Spirit Airlines, Inc. (Form: 10-Q, Received: 07/26/2018 14:29:19)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

_______________________________________________________________________

Form 10-Q

_______________________________________________________________________

(Mark One)



ý	QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended June 30, 2018



o	TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 001-35186

_______________________________________________________________________

SPIRIT AIRLINES, INC.

(Exact name of registrant as specified in its charter)

_______________________________________________________________________



Delaware	38-1747023
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)

2800 Executive Way Miramar, Florida	33025
(Address of principal executive offices)	(Zip Code)

(954) 447-7920

(Registrant’s telephone number, including area code)

_______________________________________________________________________

Indicate by check mark whether the registrant: (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes ý No o

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§ 232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes ý No o

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “small reporting company” and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):



Large accelerated filer	ý	Accelerated filer	o
Non-accelerated filer	o	Smaller reporting company	o
(Do not check if a smaller reporting company)		Emerging growth company	o

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 7(a)(2)(B) of the Securities Act. o

Indicate by check mark whether the registrant is a shell company (as defined by Rule 12b-2 of the Exchange Act). Yes o No ý

Indicate the number of shares outstanding of each of the registrant’s classes of common stock as of the close of business on July 19, 2018:



Class		Number of Shares
Common Stock, $0.0001 par value		68,252,441

Table of Contents

INDEX



			Page No.
Part I. Financial Information
	Item 1.	Condensed Financial Statements (unaudited)	1
		Condensed Statements of Operations - Three and Six Months Ended June 30, 2018 and 2017	1
		Condensed Statements of Comprehensive Income (Loss) - Three and Six Months Ended June 30, 2018 and 2017	2
		Condensed Balance Sheets – June 30, 2018 and December 31, 2017	3
		Condensed Statements of Cash Flows – Six Months Ended June 30, 2018 and 2017	4
		Notes to Condensed Financial Statements	5
	Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	27
		Glossary of Airline Terms	42
	Item 3.	Quantitative and Qualitative Disclosures About Market Risk	44
	Item 4.	Controls and Procedures	45
Part II. Other Information
	Item 1.	Legal Proceedings	46
	Item 1A.	Risk Factors	47
	Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	48
	Item 3.	Defaults Upon Senior Securities	48
	Item 4.	Mine Safety Disclosures	48
	Item 5.	Other Information	48
	Item 6.	Exhibits	49
Signature			51

PART I. Financial Information


ITEM 1.	UNAUDITED CONDENSED FINANCIAL STATEMENTS

Spirit Airlines, Inc.

Condensed Statements of Operations

(unaudited, in thousands, except per share amounts)



	Three Months Ended June 30,						Six Months Ended June 30,
	2018			2017			2018			2017
Operating revenues:
Passenger	$	836,350		$	680,880		$	1,525,491		$	1,253,167
Other	15,421			19,305			30,418			36,975
Total operating revenues	851,771			700,185			1,555,909			1,290,142

Operating expenses:
Aircraft fuel	246,180			142,294			450,826			282,076
Salaries, wages and benefits	187,756			129,892			342,852			257,030
Aircraft rent	41,745			52,566			91,936			109,636
Landing fees and other rents	58,602			45,592			108,232			86,040
Depreciation and amortization	45,618			35,331			84,991			66,840
Maintenance, materials and repairs	31,653			28,985			61,363			55,297
Distribution	34,997			29,835			65,628			55,607
Special charges	174			—			89,342			4,776
Loss on disposal of assets	4,644			1,493			5,492			2,598
Other operating	91,881			102,885			185,523			180,588
Total operating expenses	743,250			568,873			1,486,185			1,100,488

Operating income	108,521			131,312			69,724			189,654

Other (income) expense:
Interest expense	20,498			13,746			38,347			26,219
Capitalized interest	(2,296		)	(3,342		)	(4,548		)	(6,922		)
Interest income	(4,430		)	(1,828		)	(8,496		)	(3,141		)
Other expense	188			104			321			107
Special charges, non-operating	79,412			—			88,613			—
Total other (income) expense	93,372			8,680			114,237			16,263

Income (loss) before income taxes	15,149			122,632			(44,513		)	173,391
Provision (benefit) for income taxes	3,895			45,391			(10,845		)	64,889

Net income (loss)	$	11,254		$	77,241		$	(33,668	)	$	108,502
Basic earnings (loss) per share	$	0.16		$	1.11		$	(0.49	)	$	1.56
Diluted earnings (loss) per share	$	0.16		$	1.11		$	(0.49	)	$	1.56

The accompanying Notes are an integral part of these Condensed Financial Statements.

Spirit Airlines, Inc.

Condensed Statements of Comprehensive Income (Loss)

(unaudited, in thousands)



	Three Months Ended June 30,					Six Months Ended June 30,
	2018		2017			2018			2017
Net income (loss)	$	11,254	$	77,241		$	(33,668	)	$	108,502
Unrealized gain (loss) on short-term investment securities, net of deferred taxes of $33, ($6), $26 and ($14)	101		(11		)	78			(24		)
Interest rate derivative loss reclassified into earnings, net of taxes of $18, $31, $39 and $62	61		53			120			107
Other comprehensive income	$	162	$	42		$	198		$	83
Comprehensive income (loss)	$	11,416	$	77,283		$	(33,470	)	$	108,585

The accompanying Notes are an integral part of these Condensed Financial Statements.

Spirit Airlines, Inc.

Condensed Balance Sheets

(unaudited, in thousands)



	June 30, 2018			December 31, 2017
Assets
Current assets:
Cash and cash equivalents	$	812,362		$	800,849
Short-term investment securities	101,714			100,937
Accounts receivable, net	58,547			49,323
Aircraft maintenance deposits, net	107,252			175,615
Income tax receivable	70,672			69,844
Prepaid expenses and other current assets	79,788			85,542
Total current assets	1,230,335			1,282,110

Property and equipment:
Flight equipment	2,911,378			2,291,110
Ground property and equipment	168,039			155,166
Less accumulated depreciation	(261,314		)	(207,808		)
	2,818,103			2,238,468
Deposits on flight equipment purchase contracts	240,224			253,687
Long-term aircraft maintenance deposits	141,183			150,617
Deferred heavy maintenance, net	172,799			99,915
Other long-term assets	79,081			121,003
Total assets	$	4,681,725		$	4,145,800

Liabilities and shareholders’ equity
Current liabilities:
Accounts payable	$	50,310		$	22,822
Air traffic liability	357,645			263,711
Current maturities of long-term debt and capital leases	145,865			115,430
Other current liabilities	346,407			262,370
Total current liabilities	900,227			664,333

Long-term debt, less current maturities	1,731,766			1,387,498
Deferred income taxes	295,601			308,814
Deferred gains and other long-term liabilities	20,630			22,581
Shareholders’ equity:
Common stock	7			7
Additional paid-in-capital	365,536			360,153
Treasury stock, at cost	(66,840		)	(65,854		)
Retained earnings	1,436,064			1,469,732
Accumulated other comprehensive income (loss)	(1,266		)	(1,464		)
Total shareholders’ equity	1,733,501			1,762,574
Total liabilities and shareholders’ equity	$	4,681,725		$	4,145,800

The accompanying Notes are an integral part of these Condensed Financial Statements.

Spirit Airlines, Inc.

Condensed Statements of Cash Flows

(unaudited, in thousands)



	Six Months Ended June 30,
	2018			2017
Operating activities:
Net income (loss)	$	(33,668	)	$	108,502
Adjustments to reconcile net income (loss) to net cash provided by operations:
Losses reclassified from other comprehensive income	159			167
Stock-based compensation	5,381			4,671
Allowance for doubtful accounts (recoveries)	(12		)	(51		)
Amortization of deferred gains and losses and debt issuance costs	4,552			4,761
Depreciation and amortization	84,991			66,840
Deferred income tax expense (benefit)	(17,604		)	64,789
Loss on disposal of assets	5,492			2,598
Lease termination costs	—			4,776
Special charges, non-operating	88,613			—

Changes in operating assets and liabilities:
Accounts receivable	(9,212		)	(6,808		)
Aircraft maintenance deposits, net	11,222			(17,940		)
Prepaid income taxes	—			(1,598		)
Long-term deposits and other assets	3,003			(17,507		)
Deferred heavy maintenance	(94,267		)	(28,191		)
Income tax receivable	(828		)	—
Accounts payable	25,413			16,387
Air traffic liability	93,936			108,574
Other liabilities	83,809			13,518
Other	8			239
Net cash provided by operating activities	250,988			323,727
Investing activities:
Purchase of available-for-sale investment securities	(73,687		)	(68,459		)
Proceeds from the maturity of available-for-sale investment securities	72,964			67,857
Proceeds from sale of property and equipment	9,500			—
Pre-delivery deposits for flight equipment, net of refunds	(92,205		)	(79,357		)
Capitalized interest	(4,178		)	(6,375		)
Purchase of property and equipment	(323,229		)	(269,519		)
Net cash used in investing activities	(410,835		)	(355,853		)
Financing activities:
Proceeds from issuance of long-term debt	440,340			255,827
Proceeds from stock options exercised	2			29
Payments on debt obligations	(60,649		)	(49,980		)
Payments on capital lease obligations	(205,403		)	(119		)
Repurchase of common stock	(986		)	(1,217		)
Debt issuance costs	(1,944		)	(4,164		)
Net cash provided by financing activities	171,360			200,376
Net (decrease) increase in cash and cash equivalents	11,513			168,250
Cash and cash equivalents at beginning of period	800,849			700,900
Cash and cash equivalents at end of period	$	812,362		$	869,150
Supplemental disclosures
Cash payments for:
Interest, net of capitalized interest	$	16,769		$	16,869
Income taxes paid, net of refunds	$	3,270		$	4,340
Non-cash transactions:
Capital expenditures funded by capital lease borrowings	$	(315	)	$	(1,370	)

The accompanying Notes are an integral part of these Condensed Financial Statements.

Notes to Condensed Financial Statements

(unaudited)


1.	Basis of Presentation

The accompanying unaudited condensed financial statements include the accounts of Spirit Airlines, Inc. ("the Company"). These unaudited condensed financial statements reflect all normal recurring adjustments which management believes are necessary to fairly present the financial position, results of operations and cash flows of the Company for the respective periods presented. Certain information and footnote disclosures normally included in the annual financial statements prepared in accordance with U.S. generally accepted accounting principles ("GAAP") have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission for Form 10-Q. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements of the Company and notes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017 filed with the Securities and Exchange Commission on February 13, 2018.

The preparation of financial statements in conformity with GAAP requires management to make estimates and assumptions that affect both the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results may differ from these estimates.

The interim results reflected in the unaudited condensed financial statements are not necessarily indicative of the results that may be expected for other interim periods or for the full year.

Certain prior period amounts have been reclassified to conform to the current year's presentation and the adoption of Accounting Standards Update ("ASU") No. 2014-09, ("ASU 2014-09") "Revenue from Contracts with Customers".


2.	Recent Accounting Developments

Recently Adopted Accounting Pronouncements

Revenue from Contracts with Customers

In May 2014, the Financial Accounting Standards Board ("the FASB") issued Accounting Standards Update ("ASU") No. 2014-09, ("ASU 2014-09") "Revenue from Contracts with Customers." The objective of ASU 2014-09 is to establish a single comprehensive model for entities to use in accounting for revenue arising from contracts with customers. The Company adopted this guidance on January 1, 2018 utilizing the full retrospective method of adoption allowed by the standard, in order to provide for comparative results in all periods presented. The most significant impact of this ASU is the elimination of the incremental cost method for frequent flier program accounting, which requires the Company to re-value and record a liability associated with customer flight miles earned as part of the Company’s frequent flier program with a relative fair value approach. The classification and timing of recognition of certain ancillary fees is also impacted by the adoption of ASU 2014-09. While the adoption did not have a significant impact on earnings, the classification of certain revenues, such as bags, seats and other travel-related fees are now deemed part of the single performance obligation of providing passenger transportation. Refer to Note 3, Revenue Recognition for information regarding the Company's adoption of ASU 2014-09 and to Note 4, Revenue Disaggregation for the presentation of passenger revenues disaggregated by fare and non-fare.

Financial Instruments

In January 2016, the FASB issued ASU 2016-01, “Financial Instruments – Overall (Subtopic 825-10).” ASU 2016-01 makes several modifications to Subtopic 825-10 including the elimination of the available-for-sale classification of equity investments, and requires equity investments with readily determinable fair values to be measured at fair value with changes in fair value recognized in net income. ASU 2016-01 is effective for the Company for interim and annual periods beginning January 1, 2018. The Company adopted this guidance on January 1, 2018 with no material impact on the financial statements.

Statement of Cash Flows

In August 2016, the FASB issued ASU No. 2016-15, "Statement of Cash Flows." The standard is intended to reduce diversity in practice in how certain transactions are classified in the statement of cash flows. This standard is effective for the

Notes to Condensed Financial Statements—(Continued)

Company for fiscal years, and interim periods within those years, beginning January 1, 2018. The Company adopted this guidance on January 1, 2018 with no material impact on the financial statements.

Recently Issued Accounting Pronouncements Not Yet Adopted

Leases

In February 2016, the FASB issued ASU No. 2016-02, "Leases (Topic 842)." This standard will generally require all leases with durations greater than twelve months to be recognized on the condensed balance sheet and is effective for the Company in the first quarter of 2019, with early adoption permitted. The Company is currently evaluating the new guidance and believes adoption of this standard will have a significant impact on its condensed balance sheets although adoption is not expected to significantly change the recognition, measurement or presentation of lease expenses within the statements of operations and cash flows. Refer to Note 10, Commitments and Contingencies for information regarding the Company's undiscounted future lease payments and the timing of those payments.

Accounting for Credit Losses

In June 2016, the FASB issued ASU No. 2016-13, "Financial Instruments - Credit Losses." The standard requires the use of an "expected loss" model on certain types of financial instruments. The standard also amends the impairment model for available-for-sale securities and requires estimated credit losses to be recorded as allowances instead of reductions to the amortized cost of the securities. This standard is effective for the Company for fiscal years, and interim periods within those years, beginning January 1, 2020, with early adoption permitted. The Company is evaluating the new guidance, but does not expect it to have a material impact on its financial statements.

Income Taxes

In March 2018, the FASB issued ASU 2018-05, Income Taxes ("Topic 740") - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118. The standard amends Accounting Standards Codification 740, Income Taxes ("ASC 740") to provide guidance on accounting for the tax effects of the Tax Cuts and Jobs Act ("the Tax Act") pursuant to Staff Accounting Bulletin No. 118. The provisional income tax amounts recorded may be affected as the Company gains a more thorough understanding of the tax law, including those related to the deductibility of acquired assets, state tax treatment and amounts related to employee compensation. The provisional accounting impacts for the Company may change in future reporting periods until the accounting is finalized, which will occur no later than the fourth quarter of 2018. The Company does not expect the guidance to have a material impact on its financial statements.


3.	Revenue Recognition

Passenger revenues

Fare revenues. Tickets sold are initially deferred as “air traffic liability.” Passenger fare revenues are recognized at time of departure when transportation is provided. All tickets sold by the Company are nonrefundable. An unused ticket expires at the date of scheduled travel and is recognized as revenue at the date of scheduled travel. Passenger revenues reported prior to the adoption of ASU 2014-09 are now reported as fare revenues within passenger revenues in the Company's disaggregated revenue table within Note 4, Revenue Disaggregation.

As of December 31, 2017 and 2016, the Company had air traffic liability ("ATL") balances of $263.7 million and $220.2 million , respectively. During the six months ended June 30, 2018, substantially all of the ATL balance as of December 31, 2017 has been recognized. The remaining balance of the December 31, 2017 liability is expected to be recognized during the remainder of 2018.

Non-fare revenues. The adoption of ASU 2014-09 impacted the classification of certain ancillary items such as bags, seats and other travel-related fees, since they are deemed part of the single performance obligation of providing passenger transportation. These ancillary items are now recognized in non-fare revenues within passenger revenues in the Company's disaggregated revenue table within Note 4, Revenue Disaggregation.

Notes to Condensed Financial Statements—(Continued)

the original purchase price of the ticket, and the original ticket becomes invalid. For cancellations, a service charge is assessed and the amount remaining after deducting the service charge is called a credit shell which generally expires 60 days from the date the credit shell is created and can be used towards the purchase of a new ticket and the Company’s other service offerings. Both the service charge and credit shell amounts are recorded as deferred revenue and amounts expected to expire are estimated based on historical experience. Estimating the amount of credits that will go unused involves some level of subjectivity and judgment. However, given the relatively short period of time to expiration, this does not have a significant impact on the Company's financial statements.

Other revenues

Other revenues primarily consist of the marketing component of the sale of frequent flyer miles to the Company's credit card partner and commissions revenue from the sale of various items such as hotels and rental cars.

Frequent Flyer Program

The Company's frequent flyer program generates customer loyalty by rewarding customers with mileage credits to travel on Spirit. When traveling, customers earn redeemable mileage credits for each mile flown on Spirit. Customers can also earn mileage credits through participating companies such as the co-branded Spirit credit card. Mileage credits are redeemable by customers in future periods for air travel on Spirit.

To reflect the mileage credits earned, the program includes two types of transactions that are considered revenue arrangements with multiple performance obligations: (1) mileage credits earned with travel and (2) mileage credits sold to co-branded credit card partner.

The adoption of ASU 2014-09 eliminated the incremental cost method for frequent flier program accounting, which required the Company to re-value and record a liability associated with customer flight miles earned with travel as part of the Company’s frequent flier program with a relative fair value. Upon adoption of ASU 2014-09 on January 1, 2018, the Company recorded an increase to its air traffic liability of $12.4 million .

Passenger ticket sales earning mileage credits. Passenger ticket sales earning mileage credits provide customers with (1) mileage credits earned and (2) air transportation. The Company values each performance obligation on a standalone basis. To value the mileage credits earned, the Company considers the quantitative value a passenger receives by redeeming miles for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV").

The Company defers revenue for the mileage credits when earned and recognize loyalty travel awards in passenger revenue as the miles are redeemed and services are provided. The Company records the air transportation portion of the passenger ticket sales in air traffic liability and recognizes passenger revenue when transportation is provided or if the ticket goes unused.

Sale of mileage credits. Customers may earn mileage credits based on their spending with the Company's co-branded credit card company with which the Company has an agreement to sell mileage credits. The contract to sell mileage credits under this agreement has multiple performance obligations. During the six months ended June 30, 2018 and 2017, total cash sales from this agreement was $19.9 million and $25.0 million , respectively, which are allocated to travel and other performance obligations, as discussed below.

The Company's co-brand credit card agreement provides for joint marketing where cardholders earn mileage credits for making purchases using co-branded cards. During 2015, the Company extended its agreement with the administer of the FREE SPIRIT affinity credit card program to extend through 2022. The Company accounts for this agreement consistently with the accounting method that allocates the consideration received to the individual products and services delivered. The value is allocated based on the relative selling prices of those products and services, which generally consists of (i) travel miles to be awarded, (ii) licensing of brand and access to member lists and (iii) advertising and marketing efforts. The Company determined the best estimate of the selling prices by considering discounted cash flow analysis using multiple inputs and assumptions, including: (1) the expected number of miles awarded and number of miles redeemed, (2) ETV for the award travel obligation, (3) licensing of brand and access to member lists and (4) advertising and marketing efforts.

The Company defers the amount for award travel obligation as part of loyalty deferred revenue within air traffic liability on the balance sheet and recognizes loyalty travel awards in passenger revenue as the mileage credits are used for travel.

Notes to Condensed Financial Statements—(Continued)

Revenue allocated to the remaining performance obligations, primarily marketing components, is recorded in other revenue over time as miles are delivered.

Mileage breakage. For mileage credits that the Company estimates are not likely to be redeemed ("breakage"), the Company recognizes the associated value proportionally during the period in which the remaining mileage credits are redeemed. Management uses statistical models to estimate breakage based on historical redemption patterns. A change in assumptions as to the period over which mileage credits are expected to be redeemed, the actual redemption activity for mileage credits or the estimated fair value of mileage credits expected to be redeemed could have an impact on revenues in the year in which the change occurs and in future years.

Current activity of frequent flyer program. Mileage credits are combined in one homogeneous pool and are not separately identifiable. As such, the revenue is comprised of miles that were part of the frequent flyer deferred revenue balance at the beginning of the period as well as miles that were issued during the period.

The following tables show adjustments made due to the adoption of ASU 2014-09 on the December 31, 2017 and 2016 statements of operations. Previously reported results were derived from audited financial statements included in Company's Annual Report on Form 10-K for the fiscal years ended December 31, 2017 and December 31, 2016, as applicable.

Notes to Condensed Financial Statements—(Continued)



	Year Ended December 31, 2017
	(in thousands, except share and per share data)
	As Reported			Topic 606 Adjustment			As Adjusted
Operating revenues:
Passenger	$	1,366,034		$	1,206,853		$	2,572,887
Other	1,281,632			(1,210,967		)	70,665
Total operating revenues	2,647,666			(4,114		)	2,643,552

Operating expenses:
Aircraft fuel	615,581			—			615,581
Salaries, wages and benefits	527,959			—			527,959
Aircraft rent	205,852			—			205,852
Landing fees and other rents	180,655			—			180,655
Depreciation and amortization	140,152			—			140,152
Maintenance, materials and repairs	110,439			—			110,439
Distribution	113,620			(148		)	113,472
Special charges	12,629			—			12,629
Loss on disposal of assets	4,168			—			4,168
Other operating	347,820			—			347,820
Total operating expenses	2,258,875			(148		)	2,258,727

Operating income	388,791			(3,966		)	384,825

Other (income) expense:
Interest expense	57,302			—			57,302
Capitalized interest	(13,793		)	—			(13,793		)
Interest income	(8,736		)	—			(8,736		)
Other expense	366			—			366
Total other (income) expense	35,139			—			35,139

Income before income taxes	353,652			(3,966		)	349,686
Provision (benefit) for income taxes	(66,954		)	1,118			(65,836		)

Net income	$	420,606		$	(5,084	)	$	415,522
Basic earnings per share	$	6.08		$	(0.07	)	$	6.00
Diluted earnings per share	$	6.06		$	(0.07	)	$	5.99

Notes to Condensed Financial Statements—(Continued)



	Year Ended December 31, 2016
	(in thousands, except share and per share data)
	As Reported			Topic 606 Adjustment			As Adjusted
Operating revenues:
Passenger	$	1,200,621		$	1,057,180		$	2,257,801
Other	1,121,335			(1,059,115		)	62,220
Total operating revenues	2,321,956			(1,935		)	2,320,021

Operating expenses:
Salaries, wages and benefits	472,471			—			472,471
Aircraft fuel	447,553			—			447,553
Aircraft rent	201,675			—			201,675
Landing fees and other rents	151,679			—			151,679
Depreciation and amortization	101,136			—			101,136
Maintenance, materials and repairs	98,587			—			98,587
Distribution	96,627			268			96,895
Special charges	37,189			—			37,189
Loss on disposal of assets	4,187			—			4,187
Other operating	267,191			—			267,191
Total operating expenses	1,878,295			268			1,878,563

Operating income	443,661			(2,203		)	441,458

Other (income) expense:
Interest expense	41,654			—			41,654
Capitalized interest	(12,705		)	—			(12,705		)
Interest income	(5,276		)	—			(5,276		)
Other expense	528			—			528
Total other (income) expense	24,201			—			24,201

Income before income taxes	419,460			(2,203		)	417,257
Provision (benefit) for income taxes	154,581			(807		)	153,774

Net income	$	264,879		$	(1,396	)	$	263,483
Basic earnings per share	$	3.77		$	(0.02	)	$	3.75
Diluted earnings per share	$	3.76		$	(0.02	)	$	3.74

Notes to Condensed Financial Statements—(Continued)

The following table shows adjusted balances after the adoption of ASU 2014-09 on the quarterly statements of operations for each quarter of 2017.



	For the Quarter Ended
	March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017
	(in thousands, except share and per share data)
Operating revenues:
Passenger	$	572,287		$	680,880		$	669,072		$	650,647
Other	17,670			19,305			18,155			15,535
Total operating revenues	589,957			700,185			687,227			666,182

Operating expenses:
Aircraft fuel	139,782			142,294			158,300			175,205
Salaries, wages and benefits	127,138			129,892			134,114			136,815
Aircraft rent	57,070			52,566			53,396			42,820
Landing fees and other rents	40,448			45,592			48,498			46,117
Depreciation and amortization	31,509			35,331			36,840			36,472
Maintenance, materials and repairs	26,312			28,985			26,176			28,966
Distribution	25,772			29,835			29,695			28,170
Special charges	4,776			—			7,853			—
Loss on disposal of assets	1,105			1,493			516			1,054
Other operating	77,703			102,885			87,965			79,267
Total operating expenses	531,615			568,873			583,353			574,886

Operating income	58,342			131,312			103,874			91,296

Other (income) expense:
Interest expense	12,473			13,746			15,018			16,065
Capitalized interest	(3,580		)	(3,342		)	(3,203		)	(3,668		)
Interest income	(1,313		)	(1,828		)	(2,605		)	(2,990		)
Other expense	3			104			114			145
Total other (income) expense	7,583			8,680			9,324			9,552

Income before income taxes	50,759			122,632			94,550			81,744
Provision (benefit) for income taxes	19,498			45,391			34,506			(165,231		)

Net income	$	31,261		$	77,241		$	60,044		$	246,975
Basic earnings per share	$	0.45		$	1.11		$	0.87		$	3.59
Diluted earnings per share	$	0.45		$	1.11		$	0.86		$	3.58

Notes to Condensed Financial Statements—(Continued)

The following table shows quarterly adjustments made due to the adoption of ASU 2014-09 on the statements of operations for 2017.



				Adjustments for the Quarter Ended
	Full Year 2017 As Reported			March 31, 2017			June 30, 2017			September 30, 2017			December 31, 2017			Full Year 2017 Adjusted
	(in thousands, except share and per share data)
Operating revenues:
Passenger	$	1,366,034		$	272,525		$	308,959		$	312,865		$	312,504		$	2,572,887
Other	1,281,632			(274,314		)	(310,455		)	(312,869		)	(313,329		)	70,665
Total operating revenues	2,647,666			(1,789		)	(1,496		)	(4		)	(825		)	2,643,552

Operating expenses:
Aircraft fuel	615,581			—			—			—			—			615,581
Salaries, wages and benefits	527,959			—			—			—			—			527,959
Aircraft rent	205,852			—			—			—			—			205,852
Landing fees and other rents	180,655			—			—			—			—			180,655
Depreciation and amortization	140,152			—			—			—			—			140,152
Maintenance, materials and repairs	110,439			—			—			—			—			110,439
Distribution	113,620			(726		)	(73		)	226			425			113,472
Special charges	12,629			—			—			—			—			12,629
Loss on disposal of assets	4,168			—			—			—			—			4,168
Other operating	347,820			—			—			—			—			347,820
Total operating expenses	2,258,875			(726		)	(73		)	226			425			2,258,727

Operating income	388,791			(1,063		)	(1,423		)	(230		)	(1,250		)	384,825

Other (income) expense:
Interest expense	57,302			—			—			—			—			57,302
Capitalized interest	(13,793		)	—			—			—			—			(13,793		)
Interest income	(8,736		)	—			—			—			—			(8,736		)
Other expense	366			—			—			—			—			366
Total other (income) expense	35,139			—			—			—			—			35,139

Income before income taxes	353,652			(1,063		)	(1,423		)	(230		)	(1,250		)	349,686
Provision (benefit) for income taxes	(66,954		)	(389		)	(522		)	(84		)	2,113			(65,836		)

Net income	$	420,606		$	(674	)	$	(901	)	$	(146	)	$	(3,363	)	$	415,522
Basic earnings per share	$	6.08		$	(0.01	)	$	(0.01	)	$	—		$	(0.05	)	$	6.00
Diluted earnings per share	$	6.06		$	(0.01	)	$	(0.01	)	$	—		$	(0.05	)	$	5.99

Notes to Condensed Financial Statements—(Continued)

The following tables show adjustments made due to the adoption of ASU 2014-09 on the December 31, 2017 and 2016 balance sheets. Previously reported results were derived from audited financial statements included in Company's Annual Report on Form 10-K for the fiscal years ended December 31, 2017 and December 31, 2016, as applicable.



	December 31, 2017
	(in thousands)
	As Reported			Topic 606 Adjustment			As Adjusted
Assets
Current assets:
Cash and cash equivalents	$	800,849		$	—		$	800,849
Short-term investment securities	100,937			—			100,937
Accounts receivable, net	49,323			—			49,323
Aircraft maintenance deposits, net	175,615			—			175,615
Income tax receivable	69,844			—			69,844
Prepaid expenses and other current assets	83,692			1,850			85,542
Total current assets	1,280,260			1,850			1,282,110

Property and equipment:
Flight equipment	2,291,110			—			2,291,110
Ground property and equipment	155,166			—			155,166
Less accumulated depreciation	(207,808		)	—			(207,808		)
	2,238,468			—			2,238,468
Deposits on flight equipment purchase contracts	253,687			—			253,687
Long-term aircraft maintenance deposits	150,617			—			150,617
Deferred heavy maintenance, net	99,915			—			99,915
Other long-term assets	121,003			—			121,003
Total assets	$	4,143,950		$	1,850		$	4,145,800

Liabilities and shareholders’ equity
Current liabilities:
Accounts payable	$	22,822		$	—		$	22,822
Air traffic liability	246,404			17,307			263,711
Current maturities of long-term debt	115,430			—			115,430
Other current liabilities	262,370			—			262,370
Total current liabilities	647,026			17,307			664,333

Long-term debt, less current maturities	1,387,498			—			1,387,498
Deferred income taxes	313,140			(4,326		)	308,814
Deferred gains and other long-term liabilities	19,205			3,376			22,581
Shareholders’ equity:
Common stock: Common stock, $0.0001 par value, 240,000,000 shares authorized at December 31, 2017; 69,770,795 issued and 68,196,964 outstanding as of December 31, 2017	7			—			7
Additional paid-in-capital	360,153			—			360,153
Treasury stock, at cost: 1,573,831 shares as of December 31, 2017	(65,854		)	—			(65,854		)
Retained earnings	1,484,239			(14,507		)	1,469,732
Accumulated other comprehensive income (loss)	(1,464		)	—			(1,464		)
Total shareholders’ equity	1,777,081			(14,507		)	1,762,574
Total liabilities and shareholders’ equity	$	4,143,950		$	1,850		$	4,145,800

Notes to Condensed Financial Statements—(Continued)



	December 31, 2016
	(in thousands)
	As Reported			Topic 606 Adjustment			As Adjusted
Assets
Current assets:
Cash and cash equivalents	$	700,900		$	—		$	700,900
Short-term investment securities	100,155			—			100,155
Accounts receivable, net	41,136			—			41,136
Aircraft maintenance deposits, net	87,035			—			87,035
Income tax receivable	—			—			—
Prepaid expenses and other current assets	46,619			1,702			48,321
Total current assets	975,845			1,702			977,547

Property and equipment:
Flight equipment	1,461,525			—			1,461,525
Ground property and equipment	126,206			—			126,206
Less accumulated depreciation	(122,509		)	—			(122,509		)
	1,465,222			—			1,465,222
Deposits on flight equipment purchase contracts	325,688			—			325,688
Long-term aircraft maintenance deposits	199,415			—			199,415
Deferred heavy maintenance, net	75,534			—			75,534
Other long-term assets	110,223			—			110,223
Total assets	$	3,151,927		$	1,702		$	3,153,629

Liabilities and shareholders’ equity
Current liabilities:
Accounts payable	$	15,193		$	—		$	15,193
Air traffic liability	206,392			13,792			220,184
Current maturities of long-term debt	84,354			—			84,354
Other current liabilities	226,011			—			226,011
Total current liabilities	531,950			13,792			545,742

Long-term debt, less current maturities	897,359			—			897,359
Deferred income taxes	308,143			(5,443		)	302,700
Deferred gains and other long-term liabilities	19,868			2,776			22,644
Shareholders’ equity:
Common stock: Common stock, $0.0001 par value, 240,000,000 shares authorized at December 31, 2016; 73,549,872 issued and 69,326,202 outstanding as of December 31, 2016	7			—			7
Additional paid-in-capital	551,004			—			551,004
Treasury stock, at cost: 4,223,670 shares as of December 31, 2016	(218,692		)	—			(218,692		)
Retained earnings	1,063,633			(9,423		)	1,054,210
Accumulated other comprehensive income (loss)	(1,345		)	—			(1,345		)
Total shareholders’ equity	1,394,607			(9,423		)	1,385,184
Total liabilities and shareholders’ equity	$	3,151,927		$	1,702		$	3,153,629

Notes to Condensed Financial Statements—(Continued)


4.	Revenue Disaggregation

Operating revenues is comprised of passenger revenues, which includes fare and non-fare revenues, and other revenues. The following table shows disaggregated operating revenues for the first and second quarter of 2018 and each quarter of 2017.



	For the Quarter Ended
	June 30, 2018		March 31, 2018		December 31, 2017		September 30, 2017		June 30, 2017		March 31, 2017
	(in thousands)
Operating revenues:
Fare	$	439,549	$	342,695	$	337,324	$	355,593	$	371,443	$	299,035
Non-fare	396,801		346,446		313,323		313,479		309,437		273,252
Total passenger revenues	836,350		689,141		650,647		669,072		680,880		572,287
Other revenues	15,421		14,997		15,535		18,155		19,305		17,670
Total operating revenues	$	851,771	$	704,138	$	666,182	$	687,227	$	700,185	$	589,957

The following table shows disaggregated operating revenues for years ended December 31, 2017 and 2016.



	Year Ended December 31,
	2017							2016
	(in thousands)
	As Reported		Topic 606 Adjustment			As Adjusted		As Reported		Topic 606 Adjustment			As Adjusted
Operating revenues:
Fare	$	1,366,034	$	(2,639	)	$	1,363,395	$	1,200,621	$	(2,514	)	$	1,198,107
Non-fare	—		1,209,492			1,209,492		—		1,059,694			1,059,694
Total passenger revenues	1,366,034		1,206,853			2,572,887		1,200,621		1,057,180			2,257,801
Other revenues	1,281,632		(1,210,967		)	70,665		1,121,335		(1,059,115		)	62,220
Total operating revenues	$	2,647,666	$	(4,114	)	$	2,643,552	$	2,321,956	$	(1,935	)	$	2,320,021

The Company is managed as a single business unit that provides air transportation for passengers. Operating revenues by geographic region as defined by the Department of Transportation ("DOT") area are summarized below:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
	(in millions)
DOT—Domestic	$	768.3	$	640.0	$	1,417.4	$	1,184.3
DOT—Latin America	83.5		60.2		138.5		105.8
Total	$	851.8	$	700.2	$	1,555.9	$	1,290.1


5.	Special Charges

Special Charges, Operating

Notes to Condensed Financial Statements—(Continued)

During the first quarter of 2018, the Company negotiated and amended the collective bargaining agreement with the Air Line Pilots Association, International ("ALPA"), under the guidance of the National Mediation Board ("NMB"). In connection with the amended agreement, the Company incurred a one-time ratification incentive bonus of $80.7 million , including payroll taxes, and an $8.5 million adjustment related to other contractual provisions. As a result, the Company recorded $89.3 million in special charges within operating expenses in the statement of operations for the six months ended June 30, 2018 . During the second quarter of 2018, the Company paid $75.8 million of the ratification incentive bonus with the remainder expected to be paid during the third quarter of 2018.

During the six months ended June 30, 2017 , the Company purchased one engine which was previously financed under an operating lease agreement. The purchase price of the engine was $8.1 million , comprised of a cash payment of $3.8 million and the non-cash application of maintenance reserves and security deposits held by the previous lessor of $4.3 million . The Company estimated the fair value of the engine to be $3.1 million and recorded the purchased engine at fair value within flight equipment on the condensed balance sheets. The Company determined the valuation of the engine based on a third-party appraisal considering the condition of the engine (a Level 3 measurement). The Company recognized $4.8 million as a cost of terminating the lease within special charges on the condensed statement of operations, comprised of the excess of the purchase price paid over the fair value of the engine, less other non-cash items of $0.2 million .

Special Charges, Non-Operating

During the three and six months ended June 30, 2018 , the Company recorded $79.4 million and $88.6 million , respectively, in special charges, non-operating within other (income) expense in the statement of operations. During the first quarter of 2018, the Company entered into an aircraft purchase agreement for the purchase of 14 A319 aircraft previously operated under operating leases by the Company. The aggregate gross purchase price for the 14 aircraft was $285.0 million , and the price for each aircraft at the time of the sale was comprised of a cash payment net of the amount of maintenance reserves and security deposits for such aircraft held by the applicable lessor pursuant to the lease for such aircraft. The contract was deemed a lease modification which resulted in a change of classification from operating leases to capital leases for the 14 aircraft. During the first quarter of 2018, the capital lease assets were recorded at the fair value of the aircraft within flight equipment on the condensed balance sheets. During the second quarter of 2018, the purchase of the 14 aircraft was completed and the obligation was accreted up to the net cash payment price with interest charges recognized in special charges, non-operating in the statement of operations. The Company determined the valuation of the aircraft based on third-party appraisals considering the condition of the aircraft (a Level 3 measurement).


6.	Earnings per Share

The following table sets forth the computation of basic and diluted earnings (loss) per common share:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018			2017
	(in thousands, except per share amounts)
Numerator
Net income (loss)	$	11,254	$	77,241	$	(33,668	)	$	108,502
Denominator
Weighted-average shares outstanding, basic	68,251		69,370		68,237			69,359
Effect of dilutive stock awards	59		191		—			217
Adjusted weighted-average shares outstanding, diluted	68,310		69,561		68,237			69,576
Net income (loss) per share
Basic earnings (loss) per common share	$	0.16	$	1.11	$	(0.49	)	$	1.56
Diluted earnings (loss) per common share	$	0.16	$	1.11	$	(0.49	)	$	1.56

Anti-dilutive weighted-average shares	248		17		264			52

Notes to Condensed Financial Statements—(Continued)


7.	Short-term Investment Securities

The Company's short-term investment securities consist of available-for-sale asset-backed securities with contractual maturities of twelve months or less. These securities are stated at fair value within current assets on the Company's condensed balance sheets. Realized gains and losses on sales of investments, if any, are reflected in non-operating income (expense) in the condensed statements of operations.

As of June 30, 2018 and December 31, 2017 , the Company had $101.7 million and $100.9 million in short-term available-for-sale investment securities, respectively. During the six months ended June 30, 2018 , these investments earned interest income at a weighted-average fixed rate of approximately 1.4% . For the three and six months ended June 30, 2018 , an unrealized gain of $101 thousand and an unrealized gain of $78 thousand , net of deferred taxes of $33 thousand and $26 thousand , respectively, was recorded within accumulated other comprehensive income/(loss) ("AOCI") related to these investment securities. For the three and six months ended June 30, 2017 , an unrealized loss of $11 thousand and $24 thousand , net of deferred taxes of $6 thousand and $14 thousand , respectively, was recorded within AOCI related to these investment securities. The Company has not recognized any realized gains or losses related to these securities as the Company has not transacted any sale of these securities. As of June 30, 2018 and December 31, 2017 , $27 thousand and $105 thousand , net of tax, respectively, remained in AOCI, related to these instruments.


8.	Accrued Liabilities

Other current liabilities as of June 30, 2018 and December 31, 2017 consist of the following:



	June 30, 2018		December 31, 2017
	(in thousands)
Federal excise and other passenger taxes and fees payable	$	78,393	$	42,036
Salaries and wages	77,363		54,338
Airport obligations	59,981		56,299
Aircraft maintenance	44,065		33,033
Fuel	24,543		25,171
Interest payable	19,620		11,384
Aircraft and facility lease obligations	14,020		16,992
Other	28,422		23,117
Other current liabilities	$	346,407	$	262,370


9.	Financial Instruments and Risk Management

As part of the Company’s risk management program, the Company from time to time uses a variety of financial instruments to reduce its exposure to fluctuations in the price of jet fuel and interest rates. The Company does not hold or issue derivative financial instruments for trading purposes.

The Company is exposed to credit losses in the event of nonperformance by counterparties to these financial instruments. The Company periodically reviews and seeks to mitigate exposure to the financial deterioration and nonperformance of any counterparty by monitoring the absolute exposure levels, each counterparty's credit ratings and the historical performance of the counterparties relating to hedge transactions. The credit exposure related to these financial instruments is limited to the fair value of contracts in a net receivable position at the reporting date. The Company also maintains security agreements that require the Company to post collateral if the value of selected instruments falls below specified mark-to-market thresholds. The Company records financial derivative instruments at fair value, which includes an evaluation of each counterparty's credit risk. As of June 30, 2018 , the Company did not hold any derivatives with requirements to post collateral.

Fuel Derivative Instruments

From time to time, the Company may enter into fuel derivative contracts in order to mitigate the risk of future volatility in fuel prices. The Company's fuel derivative contracts, if any, generally consist of United States Gulf Coast jet fuel swaps ("jet fuel swaps") and United States Gulf Coast jet fuel options ("jet fuel options"). Both jet fuel swaps and jet fuel options are used at times to protect the refining price risk between the price of crude oil and the price of refined jet fuel, and to manage the risk of increasing fuel prices. Fair value of the instruments is determined using standard option valuation models.

Notes to Condensed Financial Statements—(Continued)

The Company accounts for any fuel derivative contracts at fair value and recognizes them in the balance sheet in prepaid expenses and other current assets or other current liabilities. The Company did not enter into any fuel derivative instruments during the six months ended June 30, 2018 and 2017 and did not have any outstanding fuel derivatives as of June 30, 2018 and December 31, 2017 . Historically, the Company has not elected hedge accounting on any fuel derivative instruments entered into and, as a result, changes in the fair value of fuel derivative contracts, if any, were recorded in aircraft fuel expense.

Interest Rate Swaps

From time to time, the Company may enter into interest rate swaps to fix the benchmark interest rate component of interest payments or for other reasons. These instruments limit the Company's exposure to changes in the benchmark interest rate in the period from the trade date through the date of maturity. Interest rate swaps may be designated as cash flow hedges. The Company generally accounts for interest rate swaps at fair value and recognizes them in the balance sheet in prepaid expenses and other current assets or other current liabilities with changes in fair value recorded within AOCI. As of June 30, 2018 and December 31, 2017 , the Company did not have any outstanding interest rate swaps.

Realized gains and losses from cash flow hedges are recorded in the statement of cash flows as a component of cash flows from operating activities. Subsequent to the issuance of each debt instrument, amounts remaining in AOCI are amortized over the life of the fixed-rate debt instrument. During the six months ended June 30, 2018 and 2017 , there were no unrealized gains or losses recorded within AOCI related to these instruments as they settled in 2015. For the three and six months ended June 30, 2018 , the Company reclassified interest rate swap losses of $61 thousand and $120 thousand , net of tax of $18 thousand and $39 thousand , respectively, into earnings. For the three and six months ended June 30, 2017 , the Company reclassified interest rate swap losses of $53 thousand and $107 thousand , net of tax of $31 thousand and $62 thousand , respectively, into earnings. As of June 30, 2018 and December 31, 2017 , $1.2 million and $1.4 million , net of tax, respectively, remained in AOCI, related to these instruments.


10.	Commitments and Contingencies

Aircraft-Related Commitments and Financing Arrangements

The Company’s contractual purchase commitments consist primarily of aircraft and engine acquisitions through manufacturers. During the first quarter of 2018, the Company negotiated revisions to its A320 aircraft order. The Company originally had 14 A320neo aircraft scheduled for delivery in 2019. Pursuant to the revisions, 5 of the 14 scheduled A320neo aircraft were converted to A320ceo aircraft and are scheduled to be delivered in 2018 and 2019. As of June 30, 2018 , the Company's aircraft orders consisted of the following:



	Airbus
	A320ceo	A320neo	Total
remainder of 2018	7		7
2019	2	9	11
2020		16	16
2021		18	18
	9	43	52

On March 28, 2018, the Company entered into an aircraft purchase agreement for the purchase of 14 A319 aircraft, which were previously financed under operating lease agreements. The contract was deemed a lease modification which resulted in a change of classification from operating leases to capital leases for the 14 aircraft. As a result, the Company recorded a short-term capital lease asset of $236.7 million within flight equipment and a short-term capital lease obligation of $143.8 million , net of the related maintenance reserves and security deposits, within current maturities of long-term debt and capital leases on the condensed balance sheet as of March 31, 2018. The purchase of all 14 aircraft was completed as of June 30, 2018 for an aggregate gross purchase price of $285.0 million , which was comprised of cash payments, net of the application of cash maintenance and security deposits held by the previous lessor. For additional information, refer to Note 5, Special Charges.

During the first quarter of 2018, the Company entered into an agreement to purchase six new engines. As of June 30, 2018, the Company had purchased four of the six new engines, unencumbered. In addition, the Company sold 5 used engines for $9.5 million at a loss of $4.4 million which is recorded within loss on disposal of assets in the statement of operations. The

Notes to Condensed Financial Statements—(Continued)

Company also has two spare engine orders for V2500 SelectTwo engines with International Aero Engines ("IAE") and nine spare engine orders for PurePower PW1100G-JM engines with Pratt & Whitney. Spare engines are scheduled for delivery from 2018 through 2023 . Purchase commitments for these aircraft and engines, including estimated amounts for contractual price escalations and pre-delivery payments, are expected to be $345.6 million for the remainder of remainder of 2018 , $600.7 million in 2019 , $821.6 million in 2020 , $785.1 million in 2021 , $16.8 million in 2022 , and $7.9 million in 2023 and beyond . As of June 30, 2018 , the Company had secured debt financing commitments of $117.0 million for 3 aircraft, scheduled for delivery in the remainder of 2018, and did not have financing commitments in place for the remaining 49 Airbus aircraft currently on firm order, which are scheduled for delivery in 2018 through 2021 .

Interest commitments related to the secured debt financing of 53 delivered aircraft as of June 30, 2018 are $40.3 million for the remainder of 2018, $73.4 million in 2019 , $67.0 million in 2020 , $60.7 million in 2021 , $54.4 million in 2022 , and $170.8 million in 2023 and beyond . For principal commitments related to these financed aircraft, refer to Note 12, Debt and Other Obligations. As of June 30, 2018 , principal and interest commitments related to the Company's future secured debt financing of 3 undelivered aircraft under the Series 2017-1 EETC are approximately $2.7 million for the remainder of 2018 , $4.4 million in 2019 , $4.0 million in 2020 , $3.8 million in 2021 , $3.6 million in 2022 , and $13.1 million in 2023 and beyond .

As of June 30, 2018 , the Company had a fleet consisting of 119 A320 family aircraft. As of June 30, 2018 , this fleet was comprised of 44 aircraft financed under operating leases, with lease term expirations between 2021 and 2029, and 75 purchased aircraft, of which 22 were purchased off lease and are currently unencumbered. In addition, as of June 30, 2018 , the Company had 12 spare engines financed under operating leases with lease term expiration dates ranging from 2019 to 2027, and owned 6 unencumbered spare engines of which 1 was purchased off lease. One of the Company's leased aircraft has variable rent payments, which fluctuate based on changes in LIBOR (London Interbank Offered Rate). The Company entered into sale leaseback transactions with third-party aircraft lessors for the majority of these aircraft and engine leases. Deferred losses resulting from these sale leaseback transactions are included in other long-term assets on the accompanying balance sheet. Deferred losses are recognized as an increase to rent expense on a straight-line basis over the term of the respective operating leases. Deferred gains are included in deferred gains and other long-term liabilities on the accompanying balance sheet. Deferred gains are recognized as a decrease to rent expense on a straight-line basis over the term of the respective operating leases.

Under the terms of the lease agreements, the Company will continue to operate and maintain the aircraft. Payments under the majority of the lease agreements are fixed for the term of the lease. The lease agreements contain standard termination events, including termination upon a breach of the Company's obligations to make rental payments and upon any other material breach of the Company's obligations under the leases, and standard maintenance and return condition provisions. These return provisions are evaluated at inception of the lease and throughout the lease terms and are accounted for as supplemental rent expense when it is probable that such amounts will be incurred. Upon a termination of the lease due to a breach by the Company, the Company would be liable for standard contractual damages, possibly including damages suffered by the lessor in connection with remarketing the aircraft or while the aircraft is not leased to another party.

In July 2015, the Company executed an upgrade service agreement with Airbus Americas Customer Services Inc. ("Airbus") to reconfigure the seating and increase capacity in 40 of the Company’s A320ceos from 178 to 182 seats ("reconfiguration"). The reconfiguration of the aircraft commenced in the first quarter of 2016 and was completed in the second quarter of 2018. As of June 30, 2018 , the Company had no further commitments related to this agreement. The amounts related to the reconfiguration are capitalized within flight equipment on the balance sheet.

Notes to Condensed Financial Statements—(Continued)

Future minimum lease payments under capital leases and noncancellable operating leases at June 30, 2018 were as follows:



		Capital Leases		Aircraft and Spare Engine Leases		Property Facility Leases		Total Operating and Capital Lease Obligations
	(in thousands)
remainder of 2018		$	329	$	86,675	$	27,457	$	114,461
2019		625		167,360		43,505		211,490
2020		249		161,876		28,398		190,523
2021		28		160,185		16,937		177,150
2022		—		146,904		16,250		163,154
2023 and thereafter		—		419,925		99,744		519,669
Total minimum lease payments		$	1,231	$	1,142,925	$	232,291	$	1,376,447
Less amount representing interest		65
Present value of minimum lease payments		$	1,166
Less current portion		599
Long-term portion		$	567

The majority of the Company's capital lease obligations relate to the lease of computer equipment used by the Company's flight crew. Payments related to the lease of computer equipment are fixed for the 3 -year term of the lease.

Aircraft rent expense consists of monthly lease rents for aircraft and spare engines under the terms of the Company's aircraft and spare engine lease agreements recognized on a straight-line basis. Aircraft rent expense also includes supplemental rent. Supplemental rent is made up of maintenance reserves paid or expected to be paid to aircraft lessors in advance of the performance of major maintenance activities that are not probable of being reimbursed, and probable and estimable return condition obligations. The Company expects supplemental rent to increase as individual aircraft lease agreements approach their respective termination dates and the Company begins to accrue the estimated cost of return conditions for the corresponding aircraft.

Some of the Company’s aircraft and engine master lease agreements provide that the Company pays maintenance reserves to aircraft lessors to be held as collateral in advance of the Company’s required performance of major maintenance activities. A majority of these maintenance reserve payments are calculated based on a utilization measure, such as flight hours or cycles, while some maintenance reserve payments are fixed, time-based contractual amounts. Fixed maintenance reserve payments for these aircraft and related flight equipment, including estimated amounts for contractual price escalations, are expected to be $3.7 million for the remainder of 2018 , $5.8 million in 2019 , $5.6 million in 2020 , $5.7 million in 2021 , $4.9 million in 2022 , and $12.9 million in 2023 and beyond . These lease agreements generally provide that maintenance reserves are reimbursable to the Company upon completion of the maintenance event. Some of the master lease agreements do not require that the Company pay maintenance reserves so long as the Company's cash balance does not fall below a certain level. As of June 30, 2018 , the Company is in full compliance with those requirements and does not anticipate having to pay reserves related to these master leases in the future.

The Company is contractually obligated to pay the following minimum guaranteed payments for its reservation system, new airport kiosks and other miscellaneous subscriptions and services as of June 30, 2018 : $5.3 million for the remainder of 2018 , $12.5 million in 2019 , $12.5 million in 2020 , $9.8 million in 2021 , $9.9 million in 2022 , and $65.8 million thereafter . During the first quarter of 2018, the Company entered into a contract renewal with its reservation system provider which expires in 2028.

Litigation

The Company is subject to commercial litigation claims and to administrative and regulatory proceedings and reviews that may be asserted or maintained from time to time. The Company believes the ultimate outcome of such lawsuits, proceedings and reviews will not, individually or in the aggregate, have a material adverse effect on its financial position, liquidity or results of operations.

Notes to Condensed Financial Statements—(Continued)

Credit Card Processing Arrangements

The Company has agreements with organizations that process credit card transactions arising from the purchase of air travel, baggage charges, and other ancillary services by customers. As is standard in the airline industry, the Company's contractual arrangements with credit card processors permit them, under certain circumstances, to retain a holdback or other collateral, which the Company records as restricted cash, when future air travel and other future services are purchased via credit card transactions. The required holdback is the percentage of the Company's overall credit card sales that its credit card processors hold to cover refunds to customers if the Company fails to fulfill its flight obligations.

The Company's credit card processors do not require the Company to maintain cash collateral provided that the Company satisfies certain liquidity and other financial covenants. Failure to meet these covenants would provide the processors the right to place a holdback resulting in a commensurate reduction of unrestricted cash. As of June 30, 2018 and December 31, 2017 , the Company was in compliance with such liquidity and other financial covenants in its credit card processing agreements and the processors were holding back no remittances.

The maximum potential exposure to cash holdbacks by the Company's credit card processors, based upon advance ticket sales and $9 Fare Club memberships as of June 30, 2018 and December 31, 2017 , was $403.0 million and $286.3 million , respectively.

Employees

The Company has four union-represented employee groups that together represented approximately 75% of all employees at June 30, 2018 . The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of June 30, 2018 .



Employee Groups	Representative	Amendable Date	Percentage of Workforce
Pilots	Air Line Pilots Association, International ("ALPA")	February 2023	27%
Flight Attendants	Association of Flight Attendants ("AFA-CWA")	May 2021	44%
Dispatchers	Professional Airline Flight Control Association ("PAFCA")	August 2018	1%
Ramp Service Agents	International Association of Machinists and Aerospace Workers ("IAMAW")	June 2020	3%

In August 2015 , the Company's collective bargaining agreement with its pilots, represented by ALPA, became amendable. In June 2016 , ALPA requested the services of the National Mediation Board ("NMB") to facilitate negotiations for an amended agreement and the Company joined ALPA in the request. In January 2018 , under the guidance of the NMB assigned mediators, the parties reached a tentative agreement. In February 2018, the pilot group voted to approve the new five -year agreement with the Company. The new agreement includes a one-time ratification incentive and other negotiated contractual provisions which were recorded in special charges within operating expenses in the condensed statement of operations for the six months ended June 30, 2018 . For additional information, refer to Note 5, Special Charges.

In December 2017, the Professional Airline Flight Control Association ("PAFCA") filed an application with the NMB seeking to represent the Company's dispatchers, who were previously represented by the Transport Workers Union ("TWU"). In January 2018, the NMB determined that a representation election would be held. The voting period for the representation election took place through February 20, 2018 and the dispatchers elected to be represented by the PAFCA. In June 2018, the Company commenced negotiations with PAFCA for an amended agreement with its dispatchers. The Company and PAFCA continue to meet on a regular basis.

In June 2018, the NMB notified the Company that the TWU filed an application seeking a representation election for the Company's passenger service agents. The application is currently pending, and if granted, would only apply to the Company's Ft. Lauderdale station where the Company has direct employees in the passenger service classification.

The Company is self-insured for health care claims, up to a stop loss amount for eligible participating employees and qualified dependent medical claims, subject to deductibles and limitations. The Company’s liabilities for claims incurred but not reported are determined based on an estimate of the ultimate aggregate liability for claims incurred. The estimate is calculated from actual claim rates and adjusted periodically as necessary. The Company has accrued $5.1 million and $3.9 million in health care claims as of June 30, 2018 and December 31, 2017 , respectively.

Notes to Condensed Financial Statements—(Continued)


11.	Fair Value Measurements

Under ASC 820, "Fair Value Measurements and Disclosures", disclosures relating to how fair value is determined for assets and liabilities are required, and a hierarchy for which these assets and liabilities must be grouped is established, based on significant levels of inputs, as follows:

Level 1 —Quoted prices in active markets for identical assets or liabilities.

Level 2 —Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.

Level 3 —Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.

Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. The Company utilizes several valuation techniques in order to assess the fair value of the Company’s financial assets and liabilities.

Fuel Derivative Instruments

From time to time, the Company may enter into fuel derivative contracts in order to mitigate the risk of future volatility in fuel prices. The Company’s fuel derivative contracts generally consist of jet fuel swaps and jet fuel options. These instruments are valued using energy and commodity market data, which is derived by combining raw inputs with quantitative models and processes to generate forward curves and volatilities.

The Company utilizes the market approach to measure fair value for its fuel derivative instruments, if any. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities.

The Company does not elect hedge accounting on its fuel derivative instruments, if any. As a result, the Company records the fair value adjustment of any fuel derivatives in the accompanying statement of operations within aircraft fuel and on the balance sheet within prepaid expenses and other current assets or other current liabilities, depending on whether the net fair value of the derivatives is in an asset or liability position as of the respective date. Fair values of any fuel derivative instruments are determined using standard option valuation models. The Company also considers counterparty risk and its own credit risk in its determination of all estimated fair values. The Company offsets fair value amounts recognized for any derivative instruments executed with the same counterparty under a master netting arrangement. The Company determines fair value of any jet fuel options utilizing an option pricing model based on inputs that are either readily available in public markets or can be derived from information available in publicly quoted markets. The Company has consistently applied these valuation techniques in all periods presented and believes it has obtained the most accurate information available for the types of derivative contracts it holds.

The fair value of the Company's jet fuel swaps, if any, are determined based on inputs that are readily available in public markets or can be derived from information available in publicly quoted markets; therefore, the Company categorizes these instruments as Level 2. Due to the fact that certain inputs utilized to determine the fair value of jet fuel options are unobservable (principally implied volatility), the Company categorizes these derivatives as Level 3. Implied volatility of a jet fuel option is the volatility of the price of the underlying commodity that is implied by the market price of the option based on an option pricing model. Thus, it is the volatility that when used in a particular pricing model yields a theoretical value for the option equal to the current market price of that option. Implied volatility, a forward-looking measure, differs from historical volatility because the latter is calculated from known past returns. At each balance sheet date, the Company substantiates and adjusts unobservable inputs. The Company routinely assesses the valuation model's sensitivity to changes in implied volatility. As of June 30, 2018 and December 31, 2017 , the Company had no outstanding jet fuel derivatives.

Long-Term Debt

The estimated fair value of the Company's term loan debt agreements has been determined to be Level 3 as certain inputs used to determine the fair value of these agreements are unobservable. The Company utilizes a discounted cash flow method to estimate the fair value of the Level 3 long-term debt. The estimated fair value of the Company's publicly and non-publicly held EETC debt agreements has been determined to be Level 2 as the Company utilizes quoted market prices in markets with low trading volumes to estimate the fair value of its Level 2 long-term debt.

Notes to Condensed Financial Statements—(Continued)

The carrying amounts and estimated fair values of the Company's long-term debt at June 30, 2018 and December 31, 2017 were as follows:



	June 30, 2018				December 31, 2017				Fair Value Level Hierarchy
	Carrying Value		Estimated Fair Value		Carrying Value		Estimated Fair Value		Fair Value Level Hierarchy
	(in millions)
Senior term loans	$	400.3	$	400.9	$	417.9	$	435.3	Level 3
Junior term loans	35.3		35.6		39.3		40.4		Level 3
Fixed-rate loans	502.0		489.5		518.0		528.6		Level 3
2015-1 EETC Class A	393.6		394.8		408.6		420.9		Level 2
2015-1 EETC Class B	84.0		84.6		92.0		94.2		Level 2
2015-1 EETC Class C	115.2		114.9		—		—		Level 2
2017-1 EETC Class AA	190.0		184.8		37.5		37.4		Level 2
2017-1 EETC Class A	63.3		61.3		12.5		12.6		Level 2
2017-1 EETC Class B	70.0		68.2		13.8		13.8		Level 2
2017-1 EETC Class C	65.7		65.5		—		—		Level 2
Total long-term debt	$	1,919.4	$	1,900.1	$	1,539.6	$	1,583.2

Cash and Cash Equivalents

Cash and cash equivalents at June 30, 2018 and December 31, 2017 are comprised of liquid money market funds and cash, and are categorized as Level 1 instruments. The Company maintains cash with various high-quality financial institutions.

Short-term Investment Securities

Short-term investment securities at June 30, 2018 and December 31, 2017 are comprised of available-for-sale asset-backed securities with contractual maturities of twelve months or less and are categorized as Level 1 instruments, as the Company uses quoted market prices in active markets when determining the fair value of these securities. For additional information, refer to Note 7, Short-term Investment Securities.

Assets and liabilities measured at gross fair value on a recurring basis are summarized below:



	Fair Value Measurements as of June 30, 2018
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	812.4	$	812.4	$	—	$	—
Short-term investment securities	101.7		101.7		—		—
Total assets	$	914.1	$	914.1	$	—	$	—

Total liabilities	$	—	$	—	$	—	$	—

Notes to Condensed Financial Statements—(Continued)



	Fair Value Measurements as of December 31, 2017
	Total		Level 1		Level 2		Level 3
	(in millions)
Cash and cash equivalents	$	800.8	$	800.8	$	—	$	—
Short-term investment securities	100.9		100.9		—		—
Total assets	$	901.7	$	901.7	$	—	$	—

Total liabilities	$	—	$	—	$	—	$	—

The Company had no transfers of assets or liabilities between any of the above levels during the periods ended June 30, 2018 and December 31, 2017 .

The Company's Valuation Group, which reports to the Chief Financial Officer, is made up of individuals from the Company's Treasury and Corporate Accounting departments. The Valuation Group is responsible for the execution of the Company's valuation policies and procedures. The Valuation Group compares the results of the Company's internally developed valuation methods with counterparty reports at each balance sheet date, assesses the Company's valuation methods for accurateness and identifies any needs for modification.


12.	Debt and Other Obligations

As of June 30, 2018 , the Company had outstanding non-public and public debt instruments. During the six months ended June 30, 2018 , the Company issued additional debt through the 2015-1 and 2017-1 EETCs described below.

2017-1 Class AA, Class A and Class B EETCs

In November 2017, the Company created three separate pass-through trusts, which issued $420.5 million aggregate face amount of Series 2017-1 Class AA, Class A and Class B EETCs in connection with the financing of seven new Airbus A320 aircraft and five new Airbus A321 aircraft. Each class of certificates represents a fractional undivided interest in the respective pass-through trusts and is not an obligation of the Company. The proceeds from the issuance of these certificates are initially held in escrow by a depositary and, upon satisfaction of certain terms and conditions, are released and used to purchase equipment notes which are issued by the Company and secured by the Company's aircraft. Interest on the issued and outstanding equipment notes are payable semiannually on February 15 and August 15 of each year, commencing on August 15, 2018, and principal on such equipment notes is scheduled for payment on February 15 and August 15 of certain years. Principal payments commence on August 15, 2018 in the case of five new Airbus A321 aircraft delivered from February 2018 to March 2018 and three Airbus A320 aircraft delivered from December 2017 to January 2018 and on February 15, 2019 for four Airbus A320 aircraft scheduled for delivery from April 2018 to October 2018. Issued and outstanding Series AA and Series A equipment notes mature in February 2030 and Series B equipment notes mature in February 2026. Issued and outstanding Series AA, Series A and Series B equipment notes accrue interest at a rate of 3.375% , 3.650% and 3.800% , respectively. As of June 30, 2018 , $323.3 million of the proceeds from the sale of the Series 2017-1 Class AA, Class A and Class B EETCs had been used to purchase equipment notes in connection with the financing of five Airbus A321 aircraft and four Airbus A320 aircraft. The remaining $97.2 million of escrowed proceeds held by the pass-through trusts will be used to purchase equipment notes as the remaining three new aircraft are delivered through October 2018. Equipment notes that are issued are reported as debt on the Company's condensed balance sheets.

2015-1C and 2017-1C EETCs

In May 2018, the Company completed a private placement of an aggregate amount of $115.2 million pass-through certificates, Series 2015-1C. The Company entered into 15 separate participation agreement amendments to existing participation agreements that were entered into by the Company during the period from October 2015 to February 2017 under the existing pass through trust formed by the Company on August 11, 2015. The Series 2015-1C equipment notes are secured by 12 Airbus A321 aircraft previously delivered from October 2015 to January 2017 and 3 Airbus A320 aircraft previously delivered from March 2016 to June 2016. The Series 2015-1C equipment notes mature in April 2023 and accrue interest at a rate of 4.93% . Principal and interest on the issued and outstanding Series 2015-1C equipment notes are payable semiannually

Notes to Condensed Financial Statements—(Continued)

on April 1 and October 1 of each year, commencing on October 1, 2018. Equipment notes that are issued are reported as debt on the Company's condensed balance sheets.

In May 2018, the Company also completed a private placement of an aggregate amount of $85.5 million pass-through certificates, Series 2017-1C. The Company entered into 9 separate participation agreement amendments to existing participation agreements that were entered into by the Company during the period from December 2017 to April 2018 under the existing pass through trust formed by the Company on November 28, 2017. The participation agreement amendments provide for the issuance of series 2017-1C equipment notes, in the aggregate principal amount of $65.7 million in connection with previously delivered aircraft. The 2017-1C equipment notes are secured by five Airbus A321 aircraft previously delivered from February 2018 to March 2018 and four Airbus A320 aircraft previously delivered from December 2017 to April 2018. The remaining $19.8 million in proceeds from the sale of the Series 2017-1C Certificates was placed in escrow and, upon satisfaction of certain terms and conditions, proceeds will be released to the Company and the Company will issue 2017-1C equipment notes to be secured by three new Airbus A320 aircraft scheduled for delivery from August 2018 through October 2018. The Series 2017-1C equipment notes mature in February 2023 and accrue interest at a rate of 5.11% . Interest on the Class C 2017-1 issued and outstanding equipment notes are payable semiannually on February 15 and August 15 of each year, commencing on August 15, 2018. The entire principal on the issued and outstanding Series 2017-1C equipment notes is scheduled for payment on February 15, 2023. Equipment notes that are issued are reported as debt on the Company's condensed balance sheets.

The Company evaluated whether the pass-through trusts formed are variable interest entities ("VIEs") required to be consolidated by the Company under applicable accounting guidance. The Company determined that the pass-through trusts are VIEs and that it does not have a variable interest in the pass-through trusts. Based on this analysis, the Company determined that it is not required to consolidate these pass-through trusts.

Long-term debt is comprised of the following:



	As of				Three Months Ended June 30,				Six Months Ended June 30,
	June 30, 2018		December 31, 2017		2018		2017		2018		2017
	(in millions)				(weighted-average interest rates)
Fixed-rate senior term loans due through 2027	$	400.3	$	417.9	4.10	%	4.10	%	4.10	%	4.10	%
Fixed-rate junior term loans due through 2022	35.3		39.3		6.90	%	6.90	%	6.90	%	6.90	%
Fixed-rate loans due through 2029	502.0		518.0		3.83	%	3.82	%	3.83	%	3.82	%
Fixed-rate class A 2015-1 EETC due through 2028	393.6		408.6		4.10	%	4.10	%	4.10	%	4.10	%
Fixed-rate class B 2015-1 EETC due through 2024	84.0		92.0		4.45	%	4.45	%	4.45	%	4.45	%
Fixed-rate class C 2015-1 EETC due through 2023	115.2		—		4.93	%	N/A		4.93	%	N/A
Fixed-rate class AA 2017-1 EETC due through 2030	190.0		37.5		3.38	%	N/A		3.38	%	N/A
Fixed-rate class A 2017-1 EETC due through 2030	63.3		12.5		3.65	%	N/A		3.65	%	N/A
Fixed-rate class B 2017-1 EETC due through 2026	70.0		13.8		3.80	%	N/A		3.80	%	N/A
Fixed-rate class C 2017-1 EETC due through 2023	65.7		—		5.11	%	N/A		5.11	%	N/A
Long-term debt	1,919.4		1,539.6
Less current maturities	145.9		115.4
Less unamortized discounts	41.7		36.7
Total	$	1,731.8	$	1,387.5

During the three and six months ended June 30, 2018 , the Company made scheduled principal payments of $42.0 million and $60.6 million on its outstanding debt obligations, respectively. During the three and six months ended June 30, 2017 , the Company made scheduled principal payments of $39.8 million and $50.0 million on its outstanding debt obligations, respectively.

At June 30, 2018 , long-term debt principal payments for the next five years and thereafter are as follows:

Notes to Condensed Financial Statements—(Continued)



	June 30, 2018
	(in millions)
remainder of 2018	$	76.6
2019	152.5
2020	150.0
2021	147.1
2022	144.0
2023 and beyond	1,249.2
Total debt principal payments	$	1,919.4

Interest Expense

Interest expense related to long-term debt consisted of the following:



	Three Months Ended June 30,				Six Months Ended June 30,
	2018		2017		2018		2017
	(in thousands)
Senior term loans	$	4,257	$	4,619	$	8,573	$	9,290
Junior term loans	636		775		1,303		1,578
Fixed-rate loans	4,881		1,586		9,792		1,744
Class A 2015-1 EETC	4,015		4,321		8,157		8,629
Class B 2015-1 EETC	930		1,108		1,942		2,292
Class C 2015-1 EETC	789		—		789		—
Class AA 2017-1 EETC	1,576		—		2,257		—
Class A 2017-1 EETC	568		—		814		—
Class B 2017-1 EETC	654		—		936		—
Class C 2017-1 EETC	466		—		466		—
Commitment fees	51		28		103		58
Amortization of debt discounts	1,655		1,290		3,146		2,521
Total	$	20,478	$	13,727	$	38,278	$	26,112


ITEM 2.	MANAGEMENT'S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Forward-Looking Statements

This Quarterly Report on Form 10-Q contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended ("the Securities Act"), and Section 21E of the Securities Exchange Act of 1934, as amended ("the Exchange Act"), which are subject to the “safe harbor” created by those sections. Forward-looking statements are based on our management’s beliefs and assumptions and on information currently available to our management. All statements other than statements of historical factors are “forward-looking statements” for purposes of these provisions. In some cases, you can identify forward-looking statements by terms such as “may,” “will,” “should,” “could,” “would,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “project,” “predict,” “potential,” and similar expressions intended to identify forward-looking statements. Such forward-looking statements are subject to risks, uncertainties and other important factors that could cause actual results and the timing of certain events to differ materially from future results expressed or implied by such forward-looking statements. Factors that could cause or contribute to such differences include, but are not limited to, those identified below, and those discussed in the section titled “Risk Factors” in this report and in Item 1A "Risk Factors" in our Annual Report on Form 10-K for the year ended December 31, 2017 and subsequent Quarterly Reports on Form 10-Q. Furthermore, such forward-looking statements speak only as of the date of this report. Except as required by law, we undertake no obligation to update any forward-looking statements to reflect events or circumstances after the date of such statements.

Overview

Spirit Airlines is an ultra low-cost, low-fare airline headquartered in Miramar, Florida that offers affordable travel to price-conscious customers. Our all-Airbus Fit Fleet ^TM is one of the youngest and most fuel efficient in the U.S. We currently operate more than 500 daily flights to 67 destinations in the United States, Latin America and the Caribbean. Our stock trades under the symbol "SAVE" on the New York Stock Exchange ("NYSE").

Our ultra low-cost carrier, or ULCC, business model allows us to compete principally by offering customers our Bare Fares ^TM , which are unbundled base fares that remove components traditionally included in the price of an airline ticket. We then give customers Frill Control ^TM , which provides customers the freedom to save by paying only for the options they choose, such as bags and advance seat assignments. We record revenue related to these options as non-fare passenger revenue, which is recorded within passenger revenues in our statement of operations.

We are focused on price-sensitive travelers who pay for their own travel, and our business model is designed to deliver what we believe our customers want: low fares. We aggressively use low fares to address an underserved market, which helps us to increase passenger volume, load factors and non-ticket revenue on the flights we operate. We also have high-density seating configurations on our aircraft and a simplified onboard product designed to lower costs, which is part of our Plane Simple ^TM strategy. High passenger volumes and load factors help us sell more ancillary products and services, which in turn allows us to reduce the base fare we offer even further. We strive to be recognized by our customers and potential customers as the low-fare leader in the markets we serve.

We compete based on total price. We believe other airlines have used an all-inclusive pricing concept to effectively maintain higher total prices to consumers, rather than lowering fares by unbundling each product or service. For example, carriers that tout “free bags” have included the cost of checking bags in the total ticket price, which does not allow passengers to see how much they would save if they did not check luggage. We believe that we and our customers benefit when we allow our customers to know the total price of their travel by breaking out the cost of optional products or services.

We allow our customers to see all available options and their respective prices prior to purchasing a ticket, and this full transparency illustrates that our total price, including options selected, is lower than other airlines on average. Through branded campaigns, we educate the public on how our unbundled pricing model works, showing them how it gives them choice on how they spend their money and saves them money compared to other airlines.

Comparative Operating Statistics:

The following tables set forth our operating statistics for the three and six -month period ended June 30, 2018 and 2017 :



	Three Months Ended June 30,				Percent Change
	2018		2017		Percent Change
Operating Statistics (unaudited) (A):
Average aircraft	118.7		102.8		15.5	%
Aircraft at end of period	119		104		14.4	%
Average daily aircraft utilization (hours)	12.6		11.7		7.7	%
Average stage length (miles)	1,051		982		7.0	%
Block hours	136,357		109,296		24.8	%
Departures	49,404		41,563		18.9	%
Passenger flight segments (PFSs) (thousands)	7,554		6,206		21.7	%
Revenue passenger miles (RPMs) (thousands)	7,961,128		6,219,638		28.0	%
Available seat miles (ASMs) (thousands)	9,515,842		7,294,578		30.5	%
Load factor (%)	83.7	%	85.3	%	(1.6) pts
Fare revenue per passenger flight segment ($)	58.19		59.85		(2.8	)%
Non-ticket revenue per passenger flight segment ($)	54.57		52.97		3.0	%
Total revenue per passenger flight segment ($)	112.76		112.82		(0.1	)%
Average yield (cents)	10.70		11.26		(5.0	)%
TRASM (cents)	8.95		9.60		(6.8	)%
CASM (cents)	7.81		7.80		0.1	%
Adjusted CASM (cents)	7.76		7.78		(0.3	)%
Adjusted CASM ex-fuel (cents)	5.17		5.83		(11.3	)%
Fuel gallons consumed (thousands)	106,144		85,533		24.1	%
Average economic fuel cost per gallon ($)	2.32		1.66		39.8	%

(A) See "Glossary of Airline Terms" elsewhere in this quarterly report for definitions used in this table. Certain prior period statistics reflect adjustments after the adoption of ASU 2014-09, "Revenue from Contracts with Customers".



	Six Months Ended June 30,				Percent Change
	2018		2017		Percent Change
Operating Statistics (unaudited) (A):
Average aircraft	116.4		100.0		16.4	%
Aircraft at end of period	119		104		14.4	%
Average daily aircraft utilization (hours)	12.3		11.8		4.2	%
Average stage length (miles)	1,038		983		5.6	%
Block hours	259,310		213,332		21.6	%
Departures	94,386		80,893		16.7	%
Passenger flight segments (PFSs) (thousands)	14,092		11,775		19.7	%
Revenue passenger miles (RPMs) (thousands)	14,774,647		11,833,060		24.9	%
Available seat miles (ASMs) (thousands)	17,924,606		14,170,478		26.5	%
Load factor (%)	82.4	%	83.5	%	(1.1) pts
Fare revenue per passenger flight segment ($)	55.51		56.94		(2.5	)%
Non-ticket revenue per passenger flight segment ($)	54.90		52.63		4.3	%
Total revenue per passenger flight segment ($)	110.41		109.57		0.8	%
Average yield (cents)	10.53		10.90		(3.4	)%
TRASM (cents)	8.68		9.10		(4.6	)%
CASM (cents)	8.29		7.77		6.7	%
Adjusted CASM (cents)	7.76		7.71		0.6	%
Adjusted CASM ex-fuel (cents)	5.25		5.72		(8.2	)%
Fuel gallons consumed (thousands)	201,147		164,597		22.2	%
Average economic fuel cost per gallon ($)	2.24		1.71		31.0	%

Critical Accounting Policies and Estimates

Except as set forth below, for information regarding our Critical Accounting Policies and Estimates, see the "Critical Accounting Policies and Estimates" section of "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations" in our Form 10-K.

Passenger revenues

Fare revenues. Tickets sold are initially deferred as “air traffic liability.” Passenger fare revenues are recognized at time of departure when transportation is provided. All tickets sold are nonrefundable. An unused ticket expires at the date of scheduled travel and is recognized as revenue at the date of scheduled travel. Passenger revenues reported prior to the adoption of ASU 2014-09 are now reported as fare revenues within passenger revenues in our disaggregated revenue table within Note 4, Revenue Disaggregation.

As of December 31, 2017 and 2016, we had air traffic liability balances of $263.7 million and $220.2 million , respectively. During the six months ended June 30, 2018, substantially all of the ATL balance as of December 31, 2017 has been recognized. The remaining balance of the December 31, 2017 liability is expected to be recognized during the remainder of 2018.

Non-fare revenues. The adoption of ASU 2014-09 impacted the classification of certain ancillary items such as bags, seats and other travel-related fees, since they are deemed part of the single performance obligation of providing passenger transportation. These ancillary items are now recognized in non-fare revenues within passenger revenues in our disaggregated revenue table within Note 4, Revenue Disaggregation.

Changes and cancellations. Customers may elect to change or cancel their itinerary prior to the date of departure. For changes, a service charge is recognized at time of departure of newly scheduled travel and is deducted from the face value of the original purchase price of the ticket, and the original ticket becomes invalid. For cancellations, a service charge is assessed and the amount remaining after deducting the service charge is called a credit shell which generally expires 60 days from the date the credit shell is created and can be used towards the purchase of a new ticket and other service offerings. Both the service charge and credit shell amounts are recorded as deferred revenue and amounts expected to expire are estimated based on historical experience. Estimating the amount of credits that will go unused involves some level of subjectivity and judgment. However, given the relatively short period of time to expiration, this does not have a significant impact on our financial statements.

Other revenues

Other revenues primarily consist of the marketing component of the sale of frequent flyer miles to our credit card partner and commissions revenue from the sale of various items such as hotels and rental cars.

Frequent Flyer Program

Our frequent flyer program generates customer loyalty by rewarding customers with mileage credits to travel on Spirit. When traveling, customers earn redeemable mileage credits for each mile flown on Spirit. Customers can also earn mileage credits through participating companies such as our co-branded Spirit credit card. Mileage credits are redeemable by customers in future periods for air travel on Spirit.

The adoption of ASU 2014-09 eliminated the incremental cost method for frequent flier program accounting, which required us to re-value and record a liability associated with customer flight miles earned with travel as part of our frequent flier program with a relative fair value. Upon adoption of ASU 2014-09 on January 1, 2018, we recorded an increase to air traffic liability of $12.4 million .

Passenger ticket sales earning mileage credits. Passenger ticket sales earning mileage credits provide customers with (1) mileage credits earned and (2) air transportation. We value each performance obligation on a standalone basis. To value the mileage credits earned, we consider the quantitative value a passenger receives by redeeming miles for a ticket rather than paying cash, which is referred to as equivalent ticket value ("ETV").

We defer revenue for the mileage credits when earned and recognize loyalty travel awards in passenger revenue as the miles are redeemed and services are provided. We record the air transportation portion of the passenger ticket sales in air traffic liability and recognize passenger revenue when we provide transportation or if the ticket goes unused.

Sale of mileage credits. Customers may earn mileage credits based on their spending with our co-branded credit card company with which we have an agreement to sell mileage credits. Our contract to sell mileage credits under this agreement has multiple performance obligations. During the six months ended June 30, 2018 and 2017, total cash sales from this agreement was $19.9 million and $25.0 million , respectively, which are allocated to travel and other performance obligations, as discussed below.

Our co-brand credit card agreement provides for joint marketing where cardholders earn mileage credits for making purchases using co-branded cards. During 2015, we extended our agreement with the administer of the FREE SPIRIT affinity credit card program to extend through 2022. We account for this agreement consistently with the accounting method that allocates the consideration received to the individual products and services delivered. We allocate the value based on the relative selling prices of those products and services, which generally consists of (i) travel miles to be awarded, (ii) licensing of brand and access to member lists and (iii) advertising and marketing efforts. We determined our best estimate of the selling prices by considering discounted cash flow analysis using multiple inputs and assumptions, including: (1) the expected number of miles awarded and number of miles redeemed, (2) ETV for the award travel obligation, (3) licensing of brand and access to member lists and (4) advertising and marketing efforts.

We defer the amount for award travel obligation as part of loyalty deferred revenue within air traffic liability on the balance sheet and recognize loyalty travel awards in passenger revenue as the mileage credits are used for travel. Revenue allocated to the remaining performance obligations, primarily marketing components, is recorded in other revenue over time as miles are delivered.

Mileage breakage. For mileage credits that we estimate are not likely to be redeemed ("breakage"), we recognize the associated value proportionally during the period in which the remaining mileage credits are redeemed. Management uses statistical models to estimate breakage based on historical redemption patterns. A change in assumptions as to the period over which mileage credits are expected to be redeemed, the actual redemption activity for mileage credits or the estimated fair value of mileage credits expected to be redeemed could have an impact on our revenue in the year in which the change occurs and in future years.

Executive Summary

For the second quarter of 2018 , we achieved a 12.7% operating margin, a decrease of 6.1 points compared to the prior year period. We generated pre-tax income of $15.1 million and net income of $11.3 million on operating revenues of $851.8 million . For the second quarter of 2017 , we generated pre-tax income of $122.6 million and net income of $77.2 million on operating revenues of $700.2 million .

Our adjusted CASM ex-fuel for the second quarter of 2018 was 5.17 cent s, an 11.3% decrease year over year. The decrease on a per-ASM basis was primarily due to decreases in other operating expense and aircraft rent expense.

As of June 30, 2018 , we had 119 Airbus A320-family aircraft in our fleet comprised of 31 A319s, 53 A320s, 30 A321s, and 5 A320neos. With the scheduled delivery of 7 aircraft during the remainder of 2018 and a contract currently under negotiation for the delivery of an additional 2 aircraft, we expect to end 2018 with 128 aircraft in our fleet.

Since the delivery of our initial five A320neo aircraft in the fourth quarter of 2016, we have experienced introductory issues with the new-generation PW1100G-JM engines, which has resulted in diminished service availability of such aircraft. As a result of the reliability problems associated with the introduction of the new engines, during the second quarter of 2017, we executed a support agreement with manufacturer Pratt & Whitney in order to obtain support and relief related to these operational disruptions. During the first quarter of 2018, the support agreement was extended through February 2018. The support agreement provided for compensation for grounded aircraft, if any, and for back-up spare engines. We continuously work with Pratt & Whitney to secure support and relief in connection with possible engine related operation disruptions.

Comparison of three months ended June 30, 2018 to three months ended June 30, 2017

Operating Revenues

Operating revenues increase d $151.6 million , or 21.6% , to $851.8 million for the second quarter of 2018 , as compared to the second quarter of 2017 , due primarily to an increase in traffic of 28.0% , offset by a decrease in passenger yields of 5.0% .

Total revenue per available seat mile ("TRASM") for the second quarter of 2018 was 8.95 cent s, a decrease of 6.8% , as compared to the second quarter of 2017 . This decrease was primarily due to lower passenger yields, year over year, driven in part by an increase in average stage length and the calendar shift of the Easter holiday, year over year.

Total revenue per passenger flight segment decreased slightly year over year. Fare revenue per passenger flight segment decrease d 2.8% and non-ticket revenue per passenger flight segment increase d 3.0% . The decrease in fare revenue per passenger flight segment was primarily driven by a 5.0% decrease in average yield, period over period. The increase in non-ticket revenue per passenger flight segment was primarily attributable to higher bag revenue, passenger usage fee, and seat revenue per flight segment, as compared to the prior year.

Operating Expenses

Operating expenses increase d $174.4 million , or 30.7% , to $743.3 million for the second quarter of 2018 compared to $568.9 million for the second quarter of 2017 , primarily due to an increase in operations as reflected by a 30.5% capacity growth and a 28.0% increase in traffic. Furthermore, operating expenses increased as a result of a 39.8% increase in average economic fuel cost per gallon and a 24.1% increase in fuel gallons consumed which drove higher aircraft fuel expense, year over year.

Aircraft fuel expense includes into-plane fuel expense (defined below) and realized and unrealized gains and losses associated with our fuel derivative contracts, if any. Into-plane fuel expense is defined as the price that we generally pay at the airport, including taxes and fees. Into-plane fuel prices are affected by the global oil market, refining costs, taxes and fees, which can vary by region in the United States and other countries where we operate. Into-plane fuel expense approximates cash paid to the supplier and does not reflect the effect of any fuel derivatives. From time to time, we may enter into fuel derivative contracts to protect the refining price risk between the price of crude oil and the price of refined jet fuel. We had no activity related to fuel derivative instruments during the three months ended June 30, 2018 and 2017 . Historically, management has chosen not to elect hedge accounting on any fuel derivative instruments and, as a result, changes in the fair value of fuel derivative contracts have been recorded each period in aircraft fuel expense.

Aircraft fuel expense increase d in the second quarter of 2018 by $103.9 million , or 73.0% , compared to $142.3 million in the second quarter of 2017, due to a 39.8% increase in average economic fuel cost per gallon and a 24.1% increase in fuel gallons consumed.

The elements of the changes in aircraft fuel expense are illustrated in the following table:



	Three Months Ended June 30,
	2018		2017
	(in thousands, except per gallon amounts)				Percent Change
Fuel gallons consumed	106,144		85,533		24.1	%
Into-plane fuel cost per gallon	$	2.32	$	1.66	39.8	%
Into-plane fuel expense	$	246,180	$	142,294	73.0	%
Realized losses (gains) related to fuel derivative contracts, net	—		—		NM
Unrealized losses (gains) related to fuel derivative contracts, net	—		—		NM
Aircraft fuel expense (per statement of operations)	$	246,180	$	142,294	73.0	%

Gulf Coast Jet indexed fuel is the basis for a substantial majority of our fuel consumption and is impacted by both the price of crude oil as well as increases or decreases in refining margins associated with the conversion of crude oil to jet fuel. The into-plane fuel cost per gallon increase of 39.8% was primarily a result of an increase in jet fuel prices.

We track economic fuel expense, which we believe is the best measure of the effect fuel prices are currently having on our business, because it most closely approximates the net cash outflow associated with purchasing fuel used for our operations during the period. We define economic fuel expense as into-plane fuel expense and realized gains or losses on fuel derivative contracts. The key difference between aircraft fuel expense as recorded in our statement of operations and economic fuel expense is unrealized mark-to-market changes in the value of aircraft fuel derivatives outstanding. Many industry analysts evaluate airline results using economic fuel expense and it is used in our internal management reporting.

The elements of the changes in economic fuel expense are illustrated in the following table:



	Three Months Ended June 30,
	2018		2017
	(in thousands, except per gallon amounts)				Percent Change
Into-plane fuel expense	$	246,180	$	142,294	73.0	%
Realized losses (gains) related to fuel derivative contracts, net	—		—		NM
Economic fuel expense	$	246,180	$	142,294	73.0	%
Fuel gallons consumed	106,144		85,533		24.1	%
Economic fuel cost per gallon	$	2.32	$	1.66	39.8	%

During the three months ended June 30, 2018 and 2017 , we had no activity related to fuel derivatives and thus had no realized or unrealized losses (gains) related to fuel derivative contracts.

We measure our operating cost performance on a per-ASM basis, since one ASM is the unit of production of an airline’s capacity. The following table presents our cost per-ASM, or unit cost, for the three months ended June 30, 2018 and 2017 , followed by explanations of the material changes on a dollar basis and/or unit cost basis:



	Three Months Ended June 30,				Dollar Change			Percent Change		Cost per ASM		Per-ASM Change		Percent Change
	2018		2017		Dollar Change			Percent Change		2018	2017	Per-ASM Change		Percent Change
	(in thousands)									(in cents)
Aircraft fuel	$	246,180	$	142,294	$	103,886		73.0	%	2.59	1.95	0.64		32.8	%
Salaries, wages, and benefits	187,756		129,892		57,864			44.5	%	1.97	1.78	0.19		10.7	%
Aircraft rent	41,745		52,566		(10,821		)	(20.6	)%	0.44	0.72	(0.28	)	(38.9	)%
Landing fees and other rents	58,602		45,592		13,010			28.5	%	0.62	0.63	(0.01	)	(1.6	)%
Depreciation and amortization	45,618		35,331		10,287			29.1	%	0.48	0.48	—		—	%
Maintenance, materials and repairs	31,653		28,985		2,668			9.2	%	0.33	0.40	(0.07	)	(17.5	)%
Distribution	34,997		29,835		5,162			17.3	%	0.37	0.41	(0.04	)	(9.8	)%
Special charges	174		—		174			NM		—	—	—		NM
Loss on disposal of assets	4,644		1,493		3,151			NM		0.05	0.02	0.03		NM
Other operating	91,881		102,885		(11,004		)	(10.7	)%	0.97	1.41	(0.44	)	(31.2	)%
Total operating expenses	$	743,250	$	568,873	$	174,377		30.7	%	7.81	7.80	0.01		0.1	%
Adjusted CASM (1)										7.76	7.78	(0.02	)	(0.3	)%
Adjusted CASM ex-fuel (2)										5.17	5.83	(0.66	)	(11.3	)%


(1)	Reconciliation of CASM to Adjusted CASM:



	Three Months Ended June 30,
	2018			2017
	(in millions)		Per ASM	(in millions)		Per ASM
CASM (cents)			7.81			7.80
Unrealized losses (gains) related to fuel derivative contracts, net	$	—	—	$	—	—
Loss on disposal of assets	4.6		0.05	1.5		0.02
Special charges	0.2		—	—		—
Adjusted CASM (cents)			7.76			7.78


(2)	Excludes aircraft fuel expense, loss on disposal of assets and special charges.

Our adjusted CASM ex-fuel for the second quarter of 2018 was down 11.3% as compared to the second quarter of 2017 . The decrease on a per-ASM basis was primarily due to decreases in other operating expense and aircraft rent expense.

Labor costs for the second quarter of 2018 increase d $57.9 million , or 44.5% , as compared to the second quarter of 2017 . The increase on both a dollar and per-ASM basis was primarily driven by a 21.3% increase in our pilot and flight attendant workforce resulting from an increase to our aircraft fleet of 15 additional aircraft, net of 2 aircraft lease returns, since the second quarter of 2017 . In addition, effective March 1, 2018, our pilots received a rate increase in connection with the new pilot agreement approved in February 2018.

Aircraft rent expense for the second quarter of 2018 decrease d by $10.8 million , or 20.6% , as compared to the second quarter of 2017 . This decrease in aircraft rent expense was primarily driven by the purchase of 14 A319 aircraft off lease completed during the second quarter of 2018. For additional information, refer to Note 5, Special Charges. On a per-ASM basis, aircraft rent expense decrease d primarily due to a change in the composition of our aircraft fleet between leased aircraft (for which rent expense is recorded under aircraft rent) and purchased aircraft (for which depreciation expense is recorded under depreciation and amortization). Since the prior year period, we have taken delivery of 17 new purchased aircraft, which

increased capacity but had no effect on aircraft rent expense, as these assets were purchased and are being depreciated over their useful life.

Landing fees and other rents for the second quarter of 2018 increase d $13.0 million , or 28.5% , as compared to the second quarter of 2017 , primarily due to an 18.9% increase in departures. In addition, landing fees and other rents increased due to an increase in facility rent resulting from the addition of new stations and rate increases at some of our existing stations. On a per-ASM basis, landing fees remained relatively stable period over period.

Depreciation and amortization for the second quarter of 2018 increase d by $10.3 million , or 29.1% , as compared to the prior year period. The increase was primarily due to increased depreciation expense resulting from the purchase of 17 new aircraft made since the second quarter of 2017 .

We account for heavy maintenance under the deferral method. Under the deferral method, the cost of heavy maintenance is capitalized and amortized as a component of depreciation and amortization expense in the statement of operations until the earlier of the next heavy maintenance event or end of the lease term. The amortization of heavy maintenance costs was $9.7 million and $14.6 million for the second quarters of 2018 and 2017 , respectively. The decrease, year over year, was primarily due to the timing of maintenance events relative to lease returns for two aircraft returned in the second half of 2017. As our fleet continues to grow and age, we expect that the amount of deferred heavy maintenance events will increase and will result in an increase in the amortization of those costs. If heavy maintenance events were amortized within maintenance, materials and repairs expense in the statement of operations, our maintenance, materials and repairs expense would have been $41.4 million and $43.6 million for the second quarters of 2018 and 2017 , respectively.

Maintenance, materials and repairs expense for the second quarter of 2018 increase d by $2.7 million , or 9.2% , as compared to the second quarter of 2017 . The increase in maintenance costs on a dollar basis was due to routine and ongoing maintenance on a growing fleet. On a per-unit basis, maintenance costs decreased as the timing and mix of maintenance events resulted in fewer expensed maintenance events. We expect maintenance expense to increase as our fleet continues to grow and age, resulting in the need for additional or more frequent repairs over time.

Distribution costs increase d by $5.2 million , or 17.3% , in the second quarter of 2018 as compared to the second quarter of 2017 . The increase on a dollar basis was primarily due to increased sales volume. On a per-ASM basis, distribution costs decreased primarily due to lower average fare resulting in a decrease in credit card fees year over year.

Other operating expense for the second quarter of 2018 decrease d by $11.0 million , or 10.7% , as compared to the second quarter of 2017 primarily due to better operational performance which resulted in lower passenger re-accommodation expense, as compared to the prior year period. On a dollar basis, this decrease was partially offset by an increase in overall operations and higher ground handling rates. As compared to the prior year period, we increased departures by 18.9% and had 21.7% more passenger flight segments, which drove increases in variable operating expenses.

Other Income (Expenses)

Our interest expense and corresponding capitalized interest for the three months ended June 30, 2018 and 2017 primarily represents interest related to the financing of purchased aircraft. As of June 30, 2018 and 2017 , we had 53 and 36 aircraft financed through secured long-term debt arrangements, respectively. Please see "Notes to Condensed Financial Statements—12. Debt and Other Obligations" for further discussion.

Our interest income for the three months ended June 30, 2018 primarily represents interest income earned on cash, cash equivalents, short-term investments and on funds required to be held in escrow in accordance with the terms of our EETC. Interest income for the three months ended June 30, 2017 primarily represents interest income earned on cash, cash equivalents and short-term investments.

Our special charges, non-operating for the three months ended June 30, 2018 , represents interest related to the aircraft purchase agreement to acquire 14 A319 aircraft previously operated under operating leases. The contract was deemed a lease modification which resulted in a change of classification from operating leases to capital leases. Please see "Notes to Condensed Financial Statements—5. Special Charges" for further discussion.

Income Taxes

Our effective tax rate for the second quarter of 2018 was 25.7% compared to 37.0% for the second quarter of 2017 . The decrease in tax rate is attributed to a reduction in the federal statutory tax rate from 35% to 21%, as a result of the enactment of the Tax Cuts and Jobs Act. While we expect our tax rate to be fairly consistent in the near term, it will tend to vary depending on recurring items such as the amount of income we earn in each state and the state tax rate applicable to such income. Discrete items particular to a given year may also affect our effective tax rates.

Comparison of six months ended June 30, 2018 to six months ended June 30, 2017

Operating Revenues

Operating revenues increase d $265.8 million , or 20.6% , to $1,555.9 million for the six months ended June 30, 2018 , compared to the prior year period, due primarily to an increase in traffic of 24.9% , offset by a decrease in passenger yields of 3.4% .

TRASM for the six months ended June 30, 2018 was 8.68 cent s, a decrease of 4.6% compared to the same period of 2017 . This decrease was driven by lower passenger yields and a decrease in load factor, year over year.

Total revenue per passenger flight segment increase d slightly from $109.57 for the six months ended June 30, 2017 to $110.41 for the six months ended June 30, 2018 . Our fare revenue per passenger flight segment decrease d from $56.94 to $55.51 , or 2.5% , as compared to the prior year period, and non-ticket revenue per passenger flight segment increase d from $52.63 to $54.90 , or 4.3% , as compared to the prior year period. The increase in non-ticket revenue per passenger flight segment was primarily attributable to higher bag revenue, passenger usage fee, and seat revenue per flight segment, as compared to the prior year.

Operating Expenses

Operating expenses increase d for the six months ended June 30, 2018 by $385.7 million , or 35.0% , as compared to the same period for 2017 primarily due to a 26.5% capacity growth and a 24.9% increase in traffic. Furthermore, operating expenses increased as a result of a 31.0% increase in average economic fuel cost per gallon and a 22.2% increase in fuel gallons consumed which drove higher aircraft fuel expense, year over year.

The elements of the changes in aircraft fuel expense are illustrated in the following table:



	Six Months Ended June 30,
	2018		2017
	(in thousands, except per gallon amounts)				Percent Change
Fuel gallons consumed	201,147		164,597		22.2	%
Into-plane fuel cost per gallon	$	2.24	$	1.71	31.0	%
Into-plane fuel expense	$	450,826	$	282,076	59.8	%
Realized losses (gains) related to fuel derivative contracts, net	—		—		NM
Unrealized losses (gains) related to fuel derivative contracts, net	—		—		NM
Aircraft fuel expense (per Statement of Operations)	$	450,826	$	282,076	59.8	%

The elements of the changes in economic fuel expense are illustrated in the following table:



	Six Months Ended June 30,
	2018		2017
	(in thousands, except per gallon amounts)				Percent Change
Into-plane fuel expense	$	450,826	$	282,076	59.8	%
Realized losses (gains) related to fuel derivative contracts, net	—		—		NM
Economic fuel expense	$	450,826	$	282,076	59.8	%
Fuel gallons consumed	201,147		164,597		22.2	%
Economic fuel cost per gallon	$	2.24	$	1.71	31.0	%

During the six months ended June 30, 2018 and 2017 , we had no activity related to fuel derivatives and thus had no realized or unrealized losses (gains) related to fuel derivative contracts.

We measure our operating cost performance on a per-ASM basis, since one ASM is the unit of production of an airline’s capacity. The following table presents our cost per-ASM, or unit cost, for the six months ended June 30, 2018 and 2017 , followed by explanations of the material changes on a unit cost basis and/or dollar basis:



	Six Months Ended June 30,				Dollar Change			Percent Change		Cost per ASM		Per-ASM Change		Percent Change
	2018		2017		Dollar Change			Percent Change		2018	2017	Per-ASM Change		Percent Change
	(in thousands)									(in cents)
Aircraft fuel	$	450,826	$	282,076	$	168,750		59.8	%	2.52	1.99	0.53		26.6	%
Salaries, wages, and benefits	342,852		257,030		85,822			33.4	%	1.91	1.81	0.10		5.5	%
Aircraft rent	91,936		109,636		(17,700		)	(16.1	)%	0.51	0.77	(0.26	)	(33.8	)%
Landing fees and other rents	108,232		86,040		22,192			25.8	%	0.60	0.61	(0.01	)	(1.6	)%
Depreciation and amortization	84,991		66,840		18,151			27.2	%	0.47	0.47	—		—	%
Maintenance, materials and repairs	61,363		55,297		6,066			11.0	%	0.34	0.39	(0.05	)	(12.8	)%
Distribution	65,628		55,607		10,021			18.0	%	0.37	0.39	(0.02	)	(5.1	)%
Special charges (credits)	89,342		4,776		84,566			NM		0.50	0.03	0.47		NM
Loss on disposal of assets	5,492		2,598		2,894			NM		0.03	0.02	0.01		NM
Other operating	185,523		180,588		4,935			2.7	%	1.04	1.27	(0.23	)	(18.1	)%
Total operating expenses	$	1,486,185	$	1,100,488	$	385,697		35.0	%	8.29	7.77	0.52		6.7	%
Adjusted CASM (1)										7.76	7.71	0.05		0.6	%
Adjusted CASM ex-fuel (2)										5.25	5.72	(0.47	)	(8.2	)%


(1)	Reconciliation of CASM to Adjusted CASM:



	Six Months Ended June 30,
	2018			2017
	(in millions)		Per ASM	(in millions)		Per ASM
CASM (cents)			8.29			7.77
Unrealized losses (gains) related to fuel derivative contracts, net	$	—	—	$	—	—
Loss on disposal of assets	5.5		0.03	2.6		0.02
Special charges	89.3		0.5	4.8		0.03
Adjusted CASM (cents)			7.76			7.71


(2)	Excludes aircraft fuel expense, loss on disposal of assets and special charges and credits.

Our adjusted CASM ex-fuel for the six months ended June 30, 2018 decrease d by 8.2% as compared to the same period in 2017 . The decrease on a per-ASM basis was primarily due to decreases in aircraft rent expense and other operating expense.

Labor costs for the six months ended June 30, 2018 increase d $85.8 million , or 33.4% , as compared to the same period in 2017 . The increase on both a dollar and per-ASM basis was primarily driven by a 24.2% increase in our pilot and flight attendant workforce resulting from an increase to our aircraft fleet of 15 additional aircraft, net of 2 aircraft lease returns, since the end of the second quarter of 2017 . In addition, effective March 1, 2018, our pilots received a rate increase in connection with the new pilot agreement approved in February 2018.

Aircraft rent expense for the six months ended June 30, 2018 decrease d by $17.7 million , or 16.1% , as compared to the same period in 2017 . This decrease in aircraft rent expense was primarily driven by the purchase of 14 A319 aircraft off lease completed during the second quarter of 2018. For additional information, refer to Note 5, Special Charges. In addition, estimated return costs recorded during the first quarter of 2017 also contributed to the decrease year over year. Costs associated with return conditions of leased aircraft are recorded as supplemental rent within aircraft rent expense on our statement of operations. On a per-ASM basis, aircraft rent expense decrease d primarily due to a change in the composition of our aircraft fleet between leased aircraft (for which rent expense is recorded under aircraft rent) and purchased aircraft (for which depreciation expense is recorded under depreciation and amortization). Since the prior year period, we have purchased 17 new aircraft, which increased capacity but had no effect on aircraft rent expense, as these assets were purchased and are being depreciated over their useful life.

Landing fees and other rents for the six months ended June 30, 2018 increase d $22.2 million , or 25.8% , as compared to the same period in 2017 primarily due to a 16.7% increase in departures. In addition, landing fees and other rents increased due to an increase in facility rent resulting from the addition of new stations and rate increases at some of our existing stations. On a per-ASM basis, landing fees remained relatively stable period over period.

Depreciation and amortization increase d by $18.2 million , or 27.2% , as compared to the prior year period. The increase on both a dollar and per-ASM basis was primarily due to increased depreciation expense resulting from the purchase of 17 new aircraft made since the second quarter of 2017 .

We account for heavy maintenance under the deferral method. Under the deferral method, the cost of heavy maintenance is capitalized and amortized as a component of depreciation and amortization expense in the statement of operations until the earlier of the next heavy maintenance event or end of the lease term. The amortization of heavy maintenance costs was $21.4 million and $27.9 million for the six months ended June 30, 2018 and 2017 , respectively. The decrease, year over year, was primarily due to the timing of maintenance events relative to lease returns for two aircraft returned in the second half of 2017. As our fleet continues to age, we expect that the amount of deferred heavy maintenance events will increase and will result in an increase in the amortization of those costs. If heavy maintenance events were amortized within maintenance, materials and repairs expense in the statement of operations, our maintenance, materials and repairs expense would have been $82.7 million and $83.2 million for the six months ended June 30, 2018 and 2017 , respectively.

Maintenance, materials and repairs expense for the six months ended June 30, 2018 increase d by $6.1 million , or 11.0% , as compared to the prior year period. The increase in maintenance costs on a dollar basis was due to routine and ongoing maintenance on a growing fleet. On a per-unit basis, maintenance costs decreased as the timing and mix of maintenance events resulted in fewer expensed maintenance events. We expect maintenance expense to increase as our fleet continues to grow and age, resulting in the need for additional or more frequent repairs over time.

Distribution costs increase d by $10.0 million , or 18.0% , for the six months ended June 30, 2018 as compared to the same period in 2017 . The increase on a dollar basis was primarily due to increased sales volume. On a per-ASM basis, distribution costs remained relatively stable, as compared to the prior period.

Other operating expense for the six months ended June 30, 2018 increase d by $4.9 million , or 2.7% , as compared to the prior period, primarily due to an increase in overall operations. As compared to the prior year period, we increase d departures by 16.7% and had 19.7% more passenger flight segments, which drove increases in variable operating expenses. Improved operational performance, year over year, resulted in lower passenger reaccommodation expense which partially offset the increase noted on a dollar basis. Lower passenger reaccommodation expense also contributed to a decrease in other operating expense on a per-ASM basis.

Special charges for the six months ended June 30, 2018 consisted of $89.3 million recognized in connection with the new pilot agreement approved in February 2018. The total amount includes a one-time $80.7 million ratification incentive bonus, including payroll taxes, and a $8.5 million adjustment related to other contractual provisions. For the six months ended June 30, 2017 , special charges consisted of $4.8 million in lease termination charges recognized in connection with the purchase of an engine formerly financed under an operating lease agreement. The amount recorded as lease termination charges represents the excess of the purchase price paid over the appraised fair value of the asset(s), less previously expensed supplemental rent and other non-cash items. For additional information, please refer to "Notes to Condensed Financial Statements - 5. Special Charges."

Other income (expenses)

Our interest expense and corresponding capitalized interest for the six months ended June 30, 2018 and 2017 primarily represents interest related to the financing of purchased aircraft. As of June 30, 2018 and 2017 , the Company had 53 and 36 aircraft financed through secured long-term debt arrangements, respectively. Please see "Notes to Condensed Financial Statements—12. Debt and Other Obligations" for further discussion.

Our interest income for the six months ended June 30, 2018 primarily represents interest income earned on cash, cash equivalents, short-term investments and on funds required to be held in escrow in accordance with the terms of our EETC. Interest income for the six months ended June 30, 2017 primarily represents interest income earned on cash, cash equivalents and short-term investments.

Our special charges, non-operating for the six months ended June 30, 2018 , represents interest related to the aircraft purchase agreement to acquire 14 A319 aircraft previously operated under operating leases. The contract was deemed a lease modification which resulted in a change of classification from operating leases to capital leases. Please see "Notes to Condensed Financial Statements—5. Special Charges" for further discussion.

Income Taxes

Our effective tax rate for the six months ended June 30, 2018 was 24.4% compared to 37.4% for the six months ended June 30, 2017 . The decrease in tax rate is attributed to a reduction in the federal statutory tax rate from 35% to 21%, as a result of the enactment of the Tax Cuts and Jobs Act. While we expect our tax rate to be fairly consistent in the near term, it will tend to vary depending on recurring items such as the amount of income we earn in each state and the state tax rate applicable to such income. Discrete items particular to a given year may also affect our effective tax rates.

Liquidity and Capital Resources

Our primary sources of liquidity are cash on hand, cash provided by operations and capital from debt financing. Primary uses of liquidity are for working capital needs, capital expenditures, aircraft and engine pre-delivery deposit payments ("PDPs"), debt obligations and maintenance reserves. Our total cash at June 30, 2018 was $812.4 million , an increase of $11.5 million from December 31, 2017 . In addition to cash and cash equivalents, as of June 30, 2018 , we had $101.7 million in short-term investment securities.

Currently, one of our largest capital expenditure needs is funding the acquisition costs of our aircraft. Aircraft may be acquired through debt financing, cash purchases, direct leases or sale leaseback transactions. During the six months ended June 30, 2018 , we purchased 7 aircraft through debt financing transactions and made $90.8 million in debt payments (principal, interest and fees) on our outstanding debt obligations. The debt entered into in the current year had maturity dates ranging from 2023 to 2030 and interest rates ranging from 3.375% to 5.110%. In addition, during the six months ended June 30, 2018 , we purchased six engines through cash purchases and sold five engines.

Under our agreement with Airbus for aircraft, and International Aero Engines AG ("IAE") and Pratt & Whitney for engines, we are required to pay PDPs relating to future deliveries at various times prior to each delivery date. During the six months ended June 30, 2018 , we paid $92.2 million in PDPs, net of refunds, and $4.2 million of capitalized interest for future deliveries of aircraft and spare engines. As of June 30, 2018 , we had $240.2 million of PDPs, including capitalized interest, on our balance sheet.

As of June 30, 2018 , we had secured financing for 3 aircraft, scheduled for delivery in the remainder of 2018, and did not have financing commitments in place for the remaining 49 Airbus firm aircraft orders, scheduled for delivery between 2018 through 2021 . Future aircraft deliveries may be paid in cash, leased or otherwise financed based on market conditions, our prevailing level of liquidity, and capital market availability. On March 28, 2018, we entered into an aircraft purchase agreement for the purchase of 14 A319s, which were previously financed under operating lease agreements. The contract was deemed a lease modification which resulted in a change of classification from operating leases to capital leases for the 14 aircraft. The purchase of all 14 aircraft was completed as of June 30, 2018, for an aggregate purchase price of $285.0 million , which was comprised of cash payments, net of the application of cash maintenance and security deposits held by the previous lessor. For additional information, refer to Note 5, Special Charges.

In addition to funding the acquisition of our future fleet, we are required to make maintenance reserve payments for some of the aircraft in our current fleet. Maintenance reserves are paid to aircraft lessors and are held as collateral in advance of our

performance of major maintenance activities. During the six months ended June 30, 2018 , we recorded an increase of $11.2 million in maintenance reserves, net of reimbursements, and as of June 30, 2018 , we had $248.4 million ( $107.3 million in aircraft maintenance deposits and $141.2 million in long-term aircraft maintenance deposits) on our condensed balance sheet.

On October 25, 2017, our Board of Directors authorized a new repurchase program of up to $100 million in aggregate value of shares of our Common Stock, par value $0.0001 per share, from time to time in open market or privately negotiated transactions. The authorization will expire on October 25, 2018. The timing and amount of any stock repurchases are subject to prevailing market conditions and other considerations. As of June 30, 2018 , we had repurchased 1.2 million shares for $44.9 million under our stock repurchase program.

Net Cash Flows Provided By Operating Activities. Operating activities in the six months ended June 30, 2018 provided $251.0 million in cash compared to $323.7 million provided in the six months ended June 30, 2017 . The decrease is primarily due to special charges recorded for the six months ended June 30, 2018 associated with the amended pilot agreement, approved in February 2018. For additional information, refer to Note 5, Special Charges. In addition, we had a decrease in deferred income tax expense and deferred heavy maintenance, year over year. These decreases were partially offset by increases in special charges, non-operating and other liabilities.

Net Cash Flows Used In Investing Activities. In the six months ended June 30, 2018 , investing activities used $410.8 million , compared to $355.9 million used in the prior year period. The increase was mainly driven by the purchase of property and equipment, year over year, resulting from increased purchases of aircraft and engines.

Net Cash Flows Provided By Financing Activities. During the six months ended June 30, 2018 , financing activities provided $171.4 million in cash compared to $200.4 million provided in the six months ended June 30, 2017 . We received $440.3 million in connection with the 2015-1C and 2017-1C EETCs and the debt financing related to seven aircraft delivered during the six months ended June 30, 2018 . In addition, we paid $60.6 million in debt obligations and $205.4 million in capital lease obligations. The payments on capital lease obligations are primarily related to an aircraft purchase agreement for the purchase of 14 A319 aircraft which were previously operated by the Company under operating leases. For additional information, refer to Note 5, Special Charges.

Commitments and Contractual Obligations

We have contractual obligations and commitments primarily with regard to future purchases of aircraft and engines, payment of debt, and lease arrangements. The following table discloses aggregate information about our contractual obligations as of June 30, 2018 and the periods in which payments are due (in millions):



	remainder of 2018		2019 - 2020		2021 - 2022		2023 and beyond		Total
Long-term debt (1)	$	77	$	303	$	291	$	1,249	$	1,920
Interest commitments (2)	40		140		115		171		466
Capital and operating lease obligations	114		402		340		520		1,376
Flight equipment purchase obligations	346		1,422		802		8		2,578
Other (3)	5		25		20		66		116
Total future payments on contractual obligations	$	582	$	2,292	$	1,568	$	2,014	$	6,456

(1) Includes principal only associated with senior and junior term loans, Class A, Class B, and Class C Series 2015-1 EETCs, and Class AA, Class A, Class B, and Class C Series 2017-1 EETCs. Refer to "Notes to the Financial Statements - 12. Debt and Other Obligations."

(2) Related to senior and junior term loans, fixed-rate loans, and Class A, Class B, and Class C Series 2015-1 EETCs, and Class AA, Class A, Class B, and Class C Series 2017-1 EETCs.

(3) Primarily related to our reservation system and other miscellaneous subscriptions and services. Refer to "Notes to the Financial Statements - 10. Commitments and Contingencies."

Some of our master lease agreements provide that we pay maintenance reserves to aircraft lessors to be held as collateral in advance of our required performance of major maintenance activities. Some maintenance reserve payments are fixed contractual amounts, while others are based on utilization. In addition to the contractual obligations disclosed in the table above, we have fixed maintenance reserve payments for these aircraft and related flight equipment, including estimated amounts for contractual price escalations, which are $3.7 million for the remainder of 2018 , $5.8 million in 2019 , $5.6 million in 2020 , $5.7 million in 2021 , $4.9 million in 2022 , and $12.9 million in 2023 and beyond .

As of June 30, 2018 , principal and interest commitments related to our future secured debt financing for 3 undelivered aircraft to be financed under the Series 2017-1 EETC are $2.7 million for the remainder of 2018 , $4.4 million in 2019 , $4.0 million in 2020 , $3.8 million in 2021 , $3.6 million in 2022 , and $13.1 million in 2023 and beyond .

Off-Balance Sheet Arrangements

We have significant obligations for aircraft and spare engines as 44 of our 119 aircraft and 12 of our 18 spare engines are financed under operating leases and therefore are not reflected on our balance sheets. These leases expire between 2019 and 2031. Aircraft rent payments were $52.5 million and $56.9 million for the three months ended June 30, 2018 and 2017 , respectively, and $109.1 million and $113.6 million for the six months ended June 30, 2018 and 2017 , respectively. Our aircraft lease payments for 43 of our aircraft are fixed-rate obligations. One of our leases provide for variable rent payments, which fluctuate based on changes in LIBOR (London Interbank Offered Rate).

Our contractual purchase commitments consist primarily of aircraft and engine acquisitions through manufacturers. During the first quarter of 2018, we negotiated revisions to our A320 aircraft order. We originally had 14 A320neo aircraft scheduled for delivery in 2019. Pursuant to the revisions, 5 of the 14 scheduled A320neo aircraft were converted to A320ceo aircraft and are scheduled to be delivered in 2018 and 2019. As of June 30, 2018 , our firm aircraft orders consisted of the following:



	Airbus
	A320ceo	A320neo	Total
remainder of 2018	7		7
2019	2	9	11
2020		16	16
2021		18	18
	9	43	52

On March 28, 2018, we entered into an aircraft purchase agreement for the purchase of 14 A319 aircraft, which were previously financed under operating lease agreements. The contract was deemed a lease modification which resulted in a change of classification from operating leases to capital leases for the 14 aircraft. As a result, we recorded a short-term capital lease asset of $236.7 million within flight equipment and a short-term capital lease obligation of $143.8 million , net of the related maintenance and security deposits, within current maturities of long-term debt and capital leases on the condensed balance sheet as of March 31, 2018. The purchase of all 14 aircraft was completed as of June 30, 2018, for an aggregate gross purchase price of $285.0 million , which was comprised of cash payments, net of the application of cash maintenance and security deposits held by the previous lessor. For additional information, refer to Note 5, Special Charges.

During the first quarter of 2018, we entered into an agreement to purchase six new engines. As of June 30, 2018 , we had purchased four of the six new engines, unencumbered. We also have two spare engine orders for V2500 SelectTwo engines with IAE and nine spare engine orders for PurePower PW 1100G-JM engines with Pratt & Whitney. Spare engines are scheduled for delivery from 2018 through 2023 . Committed expenditures for these aircraft and spare engines, including estimated amounts for contractual price escalations and aircraft PDPs, are expected to be $345.6 million for the remainder of remainder of 2018 , $600.7 million in 2019 , $821.6 million in 2020 , $785.1 million in 2021 , $16.8 million in 2022 and $7.9 million in 2023 and beyond .

As of June 30, 2018 , we had lines of credit related to corporate credit cards of $33.6 million from which we had drawn $1.1 million .

As of June 30, 2018 , we had lines of credit with counterparties for both physical fuel delivery and derivatives in the amount of $51.5 million . As of June 30, 2018 , we had drawn $23.0 million on these lines of credit for physical fuel delivery. We are required to post collateral for any excess above the lines of credit if the derivatives are in a net liability position and make periodic payments in order to maintain an adequate undrawn portion for physical fuel delivery. As of June 30, 2018 , we did not hold any derivatives.

As of June 30, 2018 , we have $9.0 million in uncollateralized surety bonds and a $35.0 million unsecured standby letter of credit facility, representing an off balance-sheet commitment, of which $17.1 million had been drawn upon for issued letters of credit.

GLOSSARY OF AIRLINE TERMS

Set forth below is a glossary of industry terms:

“Adjusted CASM” means operating expenses, excluding unrealized gains or losses related to fuel derivative contracts, out of period fuel federal excise tax, loss on disposal of assets, special charges and supplemental rent adjustment for liabilities accrued in prior years that are no longer probable, divided by ASMs.

“Adjusted CASM ex-fuel” means operating expenses excluding aircraft fuel expense, loss on disposal of assets, special charges and supplemental rent adjustment for liabilities accrued in prior years that are no longer probable, divided by ASMs.

“AFA-CWA” means the Association of Flight Attendants-CWA.

“Air traffic liability” or “ATL” means the value of tickets sold in advance of travel.

“ALPA” means the Air Line Pilots Association, International.

“ASIF” means an Aviation Security Infrastructure Fee assessed by the TSA on each airline.

“Available seat miles” or “ASMs” means the number of seats available for passengers multiplied by the number of miles the seats are flown, also referred to as "capacity".

“Average aircraft” means the average number of aircraft in our fleet as calculated on a daily basis.

“Average daily aircraft utilization” means block hours divided by number of days in the period divided by average aircraft.

“Average economic fuel cost per gallon” means total aircraft fuel expense, excluding unrealized gains or losses related to fuel derivative contracts and out of period fuel federal excise tax, divided by the total number of fuel gallons consumed.

“Average stage length” represents the average number of miles flown per flight.

“Average yield” means average operating revenue earned per RPM, calculated as total revenue divided by RPMs.

“Block hours” means the number of hours during which the aircraft is in revenue service, measured from the time of gate departure before take-off until the time of gate arrival at the destination.

“CASM” or “unit costs” means operating expenses divided by ASMs.

“CBA” means a collective bargaining agreement.

“CBP” means United States Customs and Border Protection.

“DOT” means the United States Department of Transportation.

“EPA” means the United States Environmental Protection Agency.

"EETC" means enhanced equipment trust certificate.

“FAA” means the United States Federal Aviation Administration.

“Fare revenue per passenger flight segment” means total fare passenger revenue divided by passenger flight segments.

“FCC” means the United States Federal Communications Commission.

"FLL Airport" means the Fort Lauderdale Hollywood International Airport.

“GDS” means Global Distribution System (e.g., Amadeus, Galileo, Sabre and Worldspan).

"IAMAW" means the International Association of Machinists and Aerospace Workers.

“Into-plane fuel cost per gallon” means into-plane fuel expense divided by number of fuel gallons consumed.

“Into-plane fuel expense” represents the cost of jet fuel and certain other charges such as fuel taxes and oil.

“Load factor” means the percentage of aircraft seats actually occupied on a flight (RPMs divided by ASMs).

"Non-ticket revenue" means the sum of non-fare passenger revenues and other revenues.

“Non-ticket revenue per passenger flight segment” means total non-fare passenger revenue and other revenue divided by passenger flight segments.

“NMB” means the National Mediation Board.

“OTA” means Online Travel Agent (e.g., Orbitz and Travelocity).

“Passenger flight segments” means the total number of passengers flown on all flight segments.

“PDP” means pre-delivery deposit payment.

"PAFCA" means the Professional Airline Flight Control Association.

“Revenue passenger mile” or “RPM” means one revenue passenger transported one mile. RPMs equals revenue passengers multiplied by miles flown, also referred to as “traffic”.

“RLA” means the United States Railway Labor Act.

"Total operating revenue per-ASM," "TRASM" or "unit revenue" means operating revenue divided by ASMs.

“TWU” means the Transport Workers Union of America.

“TSA” means the United States Transportation Security Administration.

“ULCC” means “ultra low-cost carrier.”


ITEM 3.	QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Market Risk-Sensitive Instruments and Positions

We are subject to certain market risks, including commodity prices (specifically aircraft fuel) and interest rates. We purchase the majority of our jet fuel at prevailing market prices and seek to manage market risk through execution of our hedging strategy and other means. We have market-sensitive instruments in the form of fixed-rate debt instruments, short-term investment securities and, from time to time, financial derivative instruments used to hedge our exposure to jet fuel price increases and interest rate increases. We do not purchase or hold any derivative financial instruments for trading purposes. The adverse effects of changes in these markets could pose a potential loss as discussed below. The sensitivity analysis provided below does not consider the effects that such adverse changes may have on overall economic activity, nor does it consider additional actions we may take to mitigate our exposure to such changes. Actual results may differ.

Aircraft Fuel . Our results of operations can vary materially due to changes in the price and availability of aircraft fuel. Aircraft fuel expense for the six months ended June 30, 2018 and 2017 represented approximately 30.3% and 25.6% of our operating expenses, respectively. Volatility in aircraft fuel prices or a shortage of supply could have a material adverse effect on our operations and operating results. We source a significant portion of our fuel from refining resources located in the southeast United States, particularly facilities adjacent to the Gulf of Mexico. Gulf Coast fuel is subject to volatility and supply disruptions, particularly during hurricane season when refinery shutdowns have occurred, or when the threat of weather related disruptions has caused Gulf Coast fuel prices to spike above other regional sources. Both jet fuel swaps and jet fuel options are used at times to protect the refining price risk between the price of crude oil and the price of refined jet fuel, and to manage the risk of increasing fuel prices. Gulf Coast Jet indexed fuel is the basis for a substantial majority of our fuel consumption. Based on our annual fuel consumption over the last twelve months, a hypothetical 10% increase in the average price per gallon of aircraft fuel would have increased into-plane aircraft fuel expense by approximately $78 million .

As of June 30, 2018 and December 31, 2017 , we did not have any outstanding jet fuel derivatives. We measure our financial derivative instruments at fair value. Fair value of the instruments is determined using standard option valuation models. Changes in the related commodity derivative instrument cash flows may change by more or less than the amount based upon further fluctuations in future prices. Outstanding financial derivative instruments expose us to credit loss in the event of nonperformance by the counterparties to the agreements. However, we do not expect the counterparties to fail to meet their obligations.

Interest Rates . We have market risk associated with our short-term investment securities, which had a fair market value of $101.7 million and $100.9 million , as of June 30, 2018 and December 31, 2017 , respectively. We also have market risk associated with changing interest rates due to LIBOR-based lease rates on one of our aircraft. A hypothetical 10% change in interest rates would affect total aircraft rent expense by less than $0.1 million per annum.

Fixed-Rate Debt . As of June 30, 2018 , we had $1,919.4 million outstanding in fixed-rate debt related to the purchase of 23 Airbus A320 aircraft and 30 Airbus A321 aircraft which had a fair value of $1,900.1 million . As of December 31, 2017 , we had $1,539.6 million outstanding in fixed-rate debt related to the purchase of 21 Airbus A320 aircraft and 25 Airbus A321 aircraft, which had a fair value of $1,583.2 million .


ITEM 4.	CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

Management, with the participation of our Chief Executive Officer and our Chief Financial Officer, evaluated the effectiveness of our disclosure controls and procedures as of June 30, 2018 . The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act, means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the our management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure.

Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure controls and procedures as of June 30, 2018 , our Chief Executive Officer and Chief Financial Officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control over Financial Reporting

There were no changes in our internal control over financial reporting (as defined in Rule 13a-15(f) under the Exchange Act) during the quarter ended June 30, 2018 , that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

PART II. OTHER INFORMATION


ITEM 1.	LEGAL PROCEEDINGS

We are subject to commercial litigation claims and to administrative and regulatory proceedings and reviews that may be asserted or maintained from time to time. We believe the ultimate outcome of such lawsuits, proceedings and reviews will not, individually or in the aggregate, have a material adverse effect on our financial position, liquidity or results of operations.


ITEM 1A.	RISK FACTORS

There have been no material changes to the risk factors disclosed in Item 1A Risk Factors contained in our Annual Report on Form 10-K for the year ended December 31, 2017 , filed with the Securities and Exchange Commission on February 13, 2018 , other than as disclosed in Part II, Item 1A. Risk Factors contained in our Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2018, filed with the Securities and Exchange Commission on April 26, 2018. Investors are urged to review these risk factors carefully.


ITEM 2.	UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

Repurchases of Equity Securities

The following table reflects our repurchases of our common stock during the second quarter of 2018 . All stock repurchases during this period were made from employees who received restricted stock awards. All employee stock repurchases were made at the election of each employee pursuant to an offer to repurchase by us. In each case, the shares repurchased constituted the portion of vested shares necessary to satisfy tax withholding requirements.



ISSUER PURCHASES OF EQUITY SECURITIES

Period	Total Number of Shares Purchased	Average Price Paid per Share		Total Number of Shares Purchased as Part of Publicly Announced Plans or Programs	Approximate Dollar Value of Shares that May Yet be Purchased Under Plans or Programs
April 1-30, 2018	103	$	35.52	—	$	55,076,306
May 1-31, 2018	135	$	36.43	—	$	55,076,306
June 1-30, 2018	507	$	37.29	—	$	55,076,306
Total	745	$	36.89	—


ITEM 3.	DEFAULTS UPON SENIOR SECURITIES

None


ITEM 4.	MINE SAFETY DISCLOSURES

Not applicable


ITEM 5.	OTHER INFORMATION

None


ITEM 6.	EXHIBITS



Exhibit Number		Description of Exhibits
4.1		Amended and Restated Intercreditor Agreement (2015-1), dated May 10, 2018, among Wilmington Trust, National Association, as Trustee of the Spirit Airlines Pass Through Trust 2015-1A, as Trustee of the Spirit Airlines Pass Through Trust 2015-1B and as Trustee of the Spirit Airlines Pass Through Trust 2015-C, Natixis, acting via its New York Branch, as Class A Liquidity Provider and Class B Liquidity Provider, and Wilmington Trust, National Association, as Subordination Agent.

4.2		Trust Supplement No. 2015-1C, dated as of May 10, 2018, between Spirit Airlines, Inc. and Wilmington Trust, National Association, as Trustee, to the Pass Through Trust Agreement, dated as of August 11, 2015.

4.3		Form of 2015-1 First Amendment to Participation Agreement (Participation Agreement among Spirit Airlines, Inc., Wilmington Trust, National Association, as Pass Through Trustee under each of the Pass Through Trust Agreements, Wilmington Trust, National Association, as Subordination Agent, Wilmington Trust, National Association, as Loan Trustee, and Wilmington Trust, National Association, in its individual capacity as set forth therein).

4.4		Form of 2015-1 First Amendment to Indenture and Security Agreement (Indenture and Security Agreement between Spirit Airlines, Inc. and Wilmington Trust, National Association, as Loan Trustee).

4.5		Amended and Restated Intercreditor Agreement (2017-1), dated May 10, 2018, among Wilmington Trust, National Association, as Trustee of the Spirit Airlines Pass Through Trust 2017-1AA, as Trustee of the Spirit Airlines Pass Through Trust 2017-1A, as Trustee of the Spirit Airlines Pass Through Trust 2017-1B and as Trustee of the Spirit Airlines Pass Through Trust 2017-1C, Commonwealth Bank of Australia, New York Branch, as Class AA Liquidity Provider, Class A Liquidity Provider and Class B Liquidity Provider, and Wilmington Trust, National Association, as Subordination Agent.

4.6		Trust Supplement No. 2017-1C, dated as of May 10, 2018, between Spirit Airlines, Inc. and Wilmington Trust, National Association, as Trustee, to the Pass Through Trust Agreement, dated as of August 11, 2015.

4.7		Amended and Restated Note Purchase Agreement, dated as of May 10, 2018, among Spirit Airlines, Inc., Wilmington Trust, National Association, as Pass Through Trustee under each of the Pass Through Trust Agreements, Wilmington Trust, National Association, as Subordination Agent, Wilmington Trust Company, as Escrow Agent, and Wilmington Trust National Association, as Paying Agent.

4.8		Form of Participation Agreement (Participation Agreement among Spirit Airlines, Inc., Wilmington Trust, National Association, as Pass Through Trustee under each of the Pass Through Trust Agreements, Wilmington Trust, National Association, as Subordination Agent, Wilmington Trust, National Association, as Loan Trustee, and Wilmington Trust, National Association, in its individual capacity as set forth therein) (Exhibit B to Note Purchase Agreement).

4.9		Form of Indenture and Security Agreement (Indenture and Security Agreement between Spirit Airlines, Inc. and Wilmington Trust, National Association, as Loan Trustee) (Exhibit C to Note Purchase Agreement).

4.10		Escrow and Paying Agent Agreement (Class C), dated as of May 10, 2018, among Wilmington Trust Company, as Escrow Agent, Morgan Stanley & Co. LLC, Citigroup Global Markets Inc., Goldman Sachs & Co. LLC and Barclays Capital Inc., as Underwriters, Wilmington Trust, National Association, not in its individual capacity, but solely as Pass Through Trustee for and on behalf of Spirit Airlines Pass Through Trust 2017-1C, and Wilmington Trust, National Association, as Paying Agent.

4.11		Deposit Agreement (Class C), dated as of May 10, 2018, between Wilmington Trust Company, as Escrow Agent, and Citibank, N.A., as Depositary.



4.12		Form of 2017-1 First Amendment to Participation Agreement (Participation Agreement among Spirit Airlines, Inc., Wilmington Trust, National Association, as Pass Through Trustee under each of the Pass Through Trust Agreements, Wilmington Trust, National Association, as Subordination Agent, Wilmington Trust, National Association, as Loan Trustee, and Wilmington Trust, National Association, in its individual capacity as set forth therein).

4.13		Form of 2017-1 First Amendment to Indenture and Security Agreement (Indenture and Security Agreement between Spirit Airlines, Inc. and Wilmington Trust, National Association, as Loan Trustee).

31.1		Certification of the Chief Executive Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

31.2		Certification of the Chief Financial Officer pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

32.1*		Certification of the Chief Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

32.2*		Certification of the Chief Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

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*	Exhibits 32.1 and 32.2 are being furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Exchange Act, or otherwise subject to the liability of that section, nor shall such exhibits be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act or the Exchange Act, except as otherwise specifically stated in such filing.

SIGNATURE

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.



	SPIRIT AIRLINES, INC.

Date: July 26, 2018	By:	/s/ Edward M. Christie
		Edward M. Christie
		President and Chief Financial Officer

Exhibit 4.1

EXECUTION VERSION

AMENDED AND RESTATED

INTERCREDITOR AGREEMENT

(2015-1)

Dated as of May 10, 2018

among

WILMINGTON TRUST, NATIONAL ASSOCIATION

as Trustee of the

Spirit Airlines Pass Through Trust 2015-1A,

Spirit Airlines Pass Through Trust 2015-1B

and

Spirit Airlines Pass Through Trust 2015-1C

NATIXIS, ACTING VIA ITS NEW YORK BRANCH

as Class A Liquidity Provider

and

Class B Liquidity Provider,

and

WILMINGTON TRUST, NATIONAL ASSOCIATION

as Subordination Agent

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)

Exhibit 4.1

Table of Contents



		Page

Article I
DEFINITIONS		2
Section 1.01	Definitions	2

Article II
TRUST ACCOUNTS; CONTROLLING PARTY
Section 2.01	Agreement to Terms of Subordination; Payments from Monies Received Only	20
Section 2.02	Trust Accounts	21
Section 2.03	Deposits to the Collection Account and Special Payments Account	22
Section 2.04	Distributions of Special Payments	22
Section 2.05	Designated Representatives	24
Section 2.06	Controlling Party	24

Article III
RECEIPT, DISTRIBUTION AND APPLICATION OF AMOUNTS RECEIVED
Section 3.01	Written Notice of Distribution	26
Section 3.02	Distribution of Amounts on Deposit in the Collection Account	27
Section 3.03	Other Payments	30
Section 3.04	Payments to the Trustees and the Liquidity Providers	30
Section 3.05	Liquidity Facilities	30

Article IV
EXERCISE OF REMEDIES
Section 4.01	Directions from the Controlling Party	38
Section 4.02	Remedies Cumulative	39
Section 4.03	Discontinuance of Proceedings	40
Section 4.04	Right of Certificateholders and the Liquidity Providers to Receive Payments Not to Be Impaired	40

Article V
DUTIES OF THE SUBORDINATION AGENT; AGREEMENTS OF TRUSTEES, ETC.
Section 5.01	Notice of Indenture Event of Default or Triggering Event	40
Section 5.02	Indemnification	41
Section 5.03	No Duties Except as Specified in Intercreditor Agreement	41
Section 5.04	Notice from the Liquidity Providers and Trustees	42

Article VI

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)

Exhibit 4.1



THE SUBORDINATION AGENT
Section 6.01	Authorization; Acceptance of Trusts and Duties	42
Section 6.02	Absence of Duties	42
Section 6.03	No Representations or Warranties as to Documents	42
Section 6.04	No Segregation of Monies; No Interest	42
Section 6.05	Reliance; Agents; Advice of Counsel	42
Section 6.06	Capacity in Which Acting	43
Section 6.07	Compensation	43
Section 6.08	May Become Certificateholder	43
Section 6.09	Subordination Agent Required; Eligibility	43
Section 6.10	Money to Be Held in Trust	44
Section 6.11	Notice of Substitution or Replacement of Airframe.	44

Article VII
SUCCESSOR SUBORDINATION AGENT
Section 7.01	Replacement of Subordination Agent; Appointment of Successor	44

Article VIII
SUPPLEMENTS AND AMENDMENTS
Section 8.01	Amendments, Waivers, Etc	45
Section 8.02	Subordination Agent Protected	49
Section 8.03	Effect of Supplemental Agreements	50
Section 8.04	Notice to Rating Agencies	50

Article IX
MISCELLANEOUS
Section 9.01	Termination of Intercreditor Agreement	50
Section 9.02	Intercreditor Agreement for Benefit of Trustees, Liquidity Providers and Subordination Agent	50
Section 9.03	Notices	50
Section 9.04	Severability	51
Section 9.05	No Oral Modifications or Continuing Waivers	51
Section 9.06	Successors and Assigns	52
Section 9.07	Headings	52
Section 9.08	Counterparts	52
Section 9.09	Subordination	52
Section 9.10	Governing Law	53
Section 9.11	Submission to Jurisdiction; Waiver of Jury Trial; Waiver of Immunity	53
Section 9.12	Non-Petition	54
Section 9.13	Acknowledgement; Direction; Amendment and Restatement	54

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



AMERICAS 94409277

Exhibit 4.1

AMENDED AND RESTATED INTERCREDITOR AGREEMENT

This AMENDED AND RESTATED INTERCREDITOR AGREEMENT, dated as of May 10, 2018, is made by and among WILMINGTON TRUST, NATIONAL ASSOCIATION, a national banking association (in its individual capacity, together with its successors and permitted assigns, “ WTNA ”), not in its individual capacity but solely as trustee of each Trust (such term and other capitalized terms used herein without definition being defined as provided in Article I); NATIXIS, a French société anonyme, acting via its New York Branch (“ Natixis ”), as Class A Liquidity Provider and Class B Liquidity Provider, and WILMINGTON TRUST, NATIONAL ASSOCIATION, not in its individual capacity except as expressly set forth herein, but solely as Subordination Agent and trustee hereunder (in such capacity, together with any successor appointed pursuant to Article VII, the “ Subordination Agent ”).

WHEREAS, the Class A Trustee, the Class B Trustee, the Class A Liquidity Provider, the Class B Liquidity Provider and the Subordination Agent entered into that certain Intercreditor Agreement (2015-1), dated as of August 11, 2015 (the “ Original Intercreditor Agreement ”);

WHEREAS, Spirit has a right to issue one or more series of “Additional Series Equipment Notes” (as defined in the Original Note Purchase Agreement) pursuant to the terms of Section 2.02 of each Indenture (as in effect immediately prior to the Class C Closing Date), Section 4(a)(v) of the Original Note Purchase Agreement and Section 8.01(d) of the Original Intercreditor Agreement, and such Section 8.01(d) provides that the Original Intercreditor Agreement shall be amended by written agreement of Spirit and the Subordination Agent to give effect to the issuance of any such “Additional Series Pass Through Certificates” (as defined in the Original Note Purchase Agreement) and the addition of the related “Additional Series Pass Through Trustee” (as defined in the Original Note Purchase Agreement) as a party to the Original Intercreditor Agreement;

WHEREAS, Spirit has entered into a Trust Supplement with respect to the Class C Trust in connection with the issuance of the Class C Certificates (which constitute an “Additional Series Pass Through Certificates”) to provide financing for the purchase by the Class C Trustee (which constitutes an “Additional Series Pass Through Trustee”) of the Series C Equipment Notes (which constitute an “Additional Series Equipment Notes”), in respect of, and secured by a security interest in, the Aircraft;

WHEREAS, the Trust created by the Class C Trust Agreement proposes to issue the Class C Certificates bearing the interest rate and having the final distribution date described in the Class C Trust Agreement on the terms and subject to the conditions set forth therein;

WHEREAS, pursuant to the Certificate Purchase Agreement, each Purchaser proposes to purchase the Class C Certificates issued by the Class C Trust in the face amount set forth opposite the name of such Purchaser on Schedule I thereto on the terms and subject to the conditions set forth therein;

WHEREAS, pursuant to the Indenture with respect to each Aircraft, Spirit has issued a Series A Equipment Note and a Series B Equipment Note and will issue a Series C Equipment Note on the date hereof;

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	1

Exhibit 4.1

WHEREAS, pursuant to the Participation Agreement with respect to each Aircraft, the Class A Trust and the Class B Trust have acquired the related Series A Equipment Note and the related Series B Equipment Note, respectively, and the Class C Trust will acquire the related Series C Equipment Note on the date hereof;

WHEREAS, the Liquidity Provider has entered into two separate revolving credit agreements on August 11, 2015 with the Subordination Agent, as agent and trustee for the Trustee of each of the Class A Trust and the Class B Trust, respectively, for the benefit of the Certificateholders of such Trust; and

WHEREAS, it is a condition precedent to the obligations of the Purchasers under the Certificate Purchase Agreement that (x) this Agreement be executed and delivered by each party hereto to amend and restate the Original Intercreditor Agreement in its entirety in connection with the issuance of the Class C Certificates and (y) the Subordination Agent, the Trustees and the Liquidity Provider agree to the terms of subordination set forth in this Agreement in respect of each Class of Certificates, and the Subordination Agent, the Trustees and the Liquidity Provider, by entering into this Agreement, hereby acknowledge and agree to such terms of subordination and the other provisions of this Agreement;

NOW, THEREFORE, in consideration of the mutual agreements herein contained, and of other good and valuable consideration the receipt and adequacy of which are hereby acknowledged, the parties hereto agree as follows:

Article I

DEFINITIONS

Section 1.01 Definitions . (a) The definitions stated herein apply equally to the singular and the plural forms of the terms defined.

(b) All references in this Agreement to designated “Articles”, “Sections” and other subdivisions are to the designated Articles, Sections and other subdivisions of this Agreement.

(c) The words “herein”, “hereof” and “hereunder” and other words of similar import refer to this Agreement as a whole and not to any particular Article, Section or other subdivision.

(d) Unless the context otherwise requires, whenever the words “including”, “include” or “includes” are used herein, it shall be deemed to be followed by the phrase “without limitation”.

(e) All references in this Agreement to a Person shall include successors and permitted assigns of such Person.

(f) For purposes of this Agreement, unless the context otherwise requires, the following capitalized terms shall have the following meanings:

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	2

Exhibit 4.1

“ 60-Day Period ” means the 60-day period specified in Section 1110(a)(2)(A) of the Bankruptcy Code.

“ Acceleration ” means, with respect to the amounts payable in respect of the Equipment Notes issued under any Indenture, such amounts becoming immediately due and payable by declaration or otherwise. “Accelerate”, “Accelerated” and “Accelerating” have meanings correlative to the foregoing.

“ Actual Disposition Event ” means, in respect of any Equipment Note: (i) the sale or disposition by the applicable Loan Trustee of the Aircraft securing such Equipment Note for cash, (ii) the occurrence of the mandatory redemption date for such Equipment Note following an Event of Loss (as defined in such Indenture) with respect to such Aircraft or (iii) the sale by the Subordination Agent of such Equipment Note for cash.

“ Additional Certificateholder ” has the meaning specified in Section 8.01(d), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Class C Certificateholder.

“ Additional Certificates ” has the meaning specified in Section 8.01(d), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement” and each Liquidity Facility, such term shall include the Class C Certificates.

“ Additional Equipment Notes ” has the meaning specified in Section 8.01(d), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Series C Equipment Notes.

“ Additional Trust ” has the meaning specified in Section 8.01(d), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Class C Trust.

“ Additional Trust Agreement ” has the meaning specified in Section 8.01(d), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Class C Trust Agreement.

“ Additional Trustee ” has the meaning specified in Section 8.01(d).

“ Administration Expenses ” has the meaning specified in clause “first” of Section 3.02.

“ Advance ” means, with respect to any Liquidity Facility, any Advance as defined in such Liquidity Facility.

“ Affiliate ” means, with respect to any Person, any other Person directly or indirectly controlling, controlled by or under direct or indirect common control with such Person. For the purposes of this definition, “control”, when used with respect to any specified Person, means the power, directly or indirectly, to direct or cause the direction of the management and policies of such Person, whether through

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	3

Exhibit 4.1

the ownership of voting securities or by contract or otherwise; and the terms “controlling” and “controlled” have meanings correlative to the foregoing.

“ Agreement ” means this Amended and Restated Intercreditor Agreement, as it may be amended, supplemented or otherwise modified from time to time.

“ Aircraft ” means, with respect to each Indenture, the “Aircraft” referred to therein.

“ Appraisal ” has the meaning specified in Section 4.01(a)(iv).

“ Appraised Current Market Value ” of any Aircraft means the lower of the average and the median of the three most recent Post-Default Appraisals of such Aircraft.

“ Appraisers ” means Aircraft Information Services, Inc., BK Associates, Inc. and Morten Beyer & Agnew, Inc. or, so long as the Person entitled or required hereunder to select such Appraiser acts reasonably, any other nationally recognized appraiser reasonably satisfactory to the Subordination Agent and the Controlling Party.

“ Available Amount ” means, with respect to any Liquidity Facility on any drawing date, subject to the proviso contained in the first sentence of Section 3.05(g), an amount equal to (a) the Stated Amount of such Liquidity Facility at such time, less (b) the aggregate amount of each Interest Drawing honored by the Liquidity Provider under such Liquidity Facility on or prior to such date that has not been reimbursed or reinstated as of such date; provided that, following a Downgrade Drawing (subject to any reinstatement of the obligations of such Liquidity Provider pursuant to Section 2.06(d) of such Liquidity Facility), a Non-Extension Drawing, a Special Termination Drawing or a Final Drawing under such Liquidity Facility, the Available Amount of such Liquidity Facility shall be zero.

“ Bankruptcy Code ” means the United States Bankruptcy Code, 11 United States Code §§101 et seq. , as amended, or any successor statutes thereto.

“ Basic Agreement ” means that certain Pass Through Trust Agreement, dated as of August 11, 2015, between Spirit and WTNA, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms, but does not include any Trust Supplement.

“ Business Day ” means, with respect to the Certificates of any Class, any day other than a Saturday, or a Sunday or a day on which commercial banks are required or authorized to close in New York, New York, Miramar, Florida, Wilmington, Delaware, or, so long as any Certificate is outstanding, the city and state in which any Trustee, the Subordination Agent or any related Loan Trustee maintains its Corporate Trust Office or receives and disburses funds, and that, solely with respect to draws under any Liquidity Facility, also is a “Business Day” as defined in such Liquidity Facility.

“ Cash Collateral Account ” means the Class A Cash Collateral Account or the Class B Cash Collateral Account, as applicable.

“ Certificate ” means a Class A Certificate, a Class B Certificate or a Class C Certificate, as applicable.

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	4

Exhibit 4.1

“ Certificate Buy-Out Event ” means that a Spirit Bankruptcy Event has occurred and is continuing and either of the following events has occurred: (A) (i) the 60-Day Period has expired, and (ii) Spirit has not entered into one or more agreements under Section 1110(a)(2)(A) of the Bankruptcy Code to perform all of its obligations under all of the Indentures and cured defaults under all of the Indentures in accordance with Section 1110(a)(2)(B) of the Bankruptcy Code or, if it has entered into such agreements, has at any time thereafter failed to cure any default under any of the Indentures in accordance with Section 1110(a)(2)(B) of the Bankruptcy Code; or (B) prior to the expiry of the 60-Day Period, Spirit shall have abandoned any Aircraft.

“ Certificate Purchase Agreement ” means the Certificate Purchase Agreement, dated as of May 10, 2018, among the Purchasers and Spirit, relating to the purchase of the Class C Certificates by the Purchasers, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Certificateholder ” means, with respect to any Class of Certificates, the Person in whose name a Certificate is registered in the Register for the Certificates of such Class.

“ Citizen of the United States ” has the meaning specified for such term in Section 40102(a)(15) of Title 49 of the United States Code or any similar legislation of the United States enacted in substitution or replacement therefor.

“ Class ” means a single class of Certificates issued by a Trust pursuant to a Trust Agreement.

“ Class A Cash Collateral Account ” means, in respect of the Class A Liquidity Facility, an Eligible Deposit Account in the name of the Subordination Agent maintained at an Eligible Institution, which shall be the Subordination Agent if it so qualifies, into which amounts shall be deposited as referred to in Section 3.05(f).

“ Class A Certificateholder ” means, at any time, any Certificateholder of one or more Class A Certificates.

“ Class A Certificates ” means the certificates issued by the Class A Trust, substantially in the form of Exhibit A to the Class A Trust Agreement, and authenticated by the Class A Trustee, representing Fractional Undivided Interests in the Class A Trust, and any certificates issued in exchange therefor or replacement thereof pursuant to the terms of the Class A Trust Agreement.

“ Class A Liquidity Expenses ” means all Class A Liquidity Obligations other than (i) the principal amount of any Drawings under the Class A Liquidity Facility and (ii) any interest accrued on any Class A Liquidity Obligations.

“ Class A Liquidity Facility ” means, initially, the Revolving Credit Agreement (2015-1A), dated as of August 11, 2015, between the Subordination Agent, as agent and trustee for the Class A Trustee, and Natixis and, from and after the replacement of such agreement pursuant hereto, the Replacement Liquidity Facility therefor, if any, in each case as amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligation of Spirit, no amendment, modification

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	5

Exhibit 4.1

or supplement to, or substitution or replacement of, any Class A Liquidity Facility shall be effective unless consented to by Spirit.

“ Class A Liquidity Obligations ” means all principal, interest, fees and other amounts owing to the Class A Liquidity Provider under the Class A Liquidity Facility, Section 4.02 of the Participation Agreements or the applicable Fee Letter.

“ Class A Liquidity Provider ” means Natixis, together with any Replacement Liquidity Provider that has issued a Replacement Liquidity Facility to replace the Class A Liquidity Facility pursuant to Section 3.05(c) or 3.05(e).

“ Class A Trust ” means the Spirit Airlines Pass Through Trust 2015-1A created and administered pursuant to the Class A Trust Agreement.

“ Class A Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2015-1A thereto, dated as of August 11, 2015, governing the creation and administration of the Spirit Airlines Pass Through Trust 2015-1A and the issuance of the Class A Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Class A Trustee ” means WTNA, not in its individual capacity except as expressly set forth in the Class A Trust Agreement, but solely as trustee under the Class A Trust Agreement, together with any successor trustee appointed pursuant thereto.

“ Class B Adjusted Interest ” means, as of any Current Distribution Date: (I) any interest described in clause (II) of this definition accrued prior to the immediately preceding Distribution Date which remains unpaid and (II) the sum of (A) interest determined at the Stated Interest Rate for the Class B Certificates for the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Closing Date) and ending on, but excluding, the Current Distribution Date, on the Eligible B Pool Balance on such Current Distribution Date and (B) the sum of interest for each Series B Equipment Note with respect to which, or with respect to the Aircraft with respect to which such Equipment Note was issued, a disposition, distribution, sale or Deemed Disposition Event has occurred since the immediately preceding Distribution Date (but only if no such event has previously occurred with respect to such Series B Equipment Note), determined at the Stated Interest Rate for the Class B Certificates for each day during the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Closing Date) and ending on, but excluding, the date of the earliest of such disposition, distribution, sale or Deemed Disposition Event with respect to such Series B Equipment Note or such Aircraft, as the case may be, on the principal amount of such Series B Equipment Note calculated pursuant to clause (B)(i), (ii), (iii) or (iv), as applicable, of the definition of Eligible B Pool Balance.

“ Class B Cash Collateral Account ” means, in respect of the Class B Liquidity Facility, an Eligible Deposit Account in the name of the Subordination Agent maintained at an Eligible Institution, which shall be the Subordination Agent if it so qualifies, into which amounts shall be deposited as referred to in Section 3.05(f).

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	6

Exhibit 4.1

“ Class B Certificateholder ” means, at any time, any Certificateholder of one or more Class B Certificates.

“ Class B Certificates ” means the certificates issued by the Class B Trust, substantially in the form of Exhibit A to the Class B Trust Agreement, and authenticated by the Class B Trustee, representing Fractional Undivided Interests in the Class B Trust, and any certificates issued in exchange therefor or replacement thereof pursuant to the terms of the Class B Trust Agreement.

“ Class B Liquidity Expenses ” means all Class B Liquidity Obligations other than (i) the principal amount of any Drawings under the Class B Liquidity Facility and (ii) any interest accrued on any Class B Liquidity Obligations.

“ Class B Liquidity Facility ” means, initially, the Revolving Credit Agreement (2015-1B), dated as of August 11, 2015, between the Subordination Agent, as agent and trustee for the Class B Trustee, and Natixis and, from and after the replacement of such agreement pursuant hereto, the Replacement Liquidity Facility therefor, if any, in each case as amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligation of Spirit, no amendment, modification or supplement to, or substitution or replacement of, any Class B Liquidity Facility shall be effective unless consented to by Spirit.

“ Class B Liquidity Obligations ” means all principal, interest, fees and other amounts owing to the Class B Liquidity Provider under the Class B Liquidity Facility, Section 4.02 of the Participation Agreements or the applicable Fee Letter.

“ Class B Liquidity Provider ” means Natixis, together with any Replacement Liquidity Provider that has issued a Replacement Liquidity Facility to replace the Class B Liquidity Facility pursuant to Section 3.05(c) or 3.05(e).

“ Class B Trust ” means the Spirit Airlines Pass Through Trust 2015-1B created and administered pursuant to the Class B Trust Agreement.

“ Class B Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2015-1B thereto, dated as of August 11, 2015, governing the creation and administration of the Spirit Airlines Pass Through Trust 2015-1B and the issuance of the Class B Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Class B Trustee ” means WTNA, not in its individual capacity except as expressly set forth in the Class B Trust Agreement, but solely as trustee under the Class B Trust Agreement, together with any successor trustee appointed pursuant thereto.

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	7

Exhibit 4.1

and (B) the sum of interest for each Series C Equipment Note with respect to which, or with respect to the Aircraft with respect to which such Equipment Note was issued, a disposition, distribution, sale or Deemed Disposition Event has occurred since the immediately preceding Distribution Date (but only if no such event has previously occurred with respect to such Series C Equipment Note), determined at the Stated Interest Rate for the Class C Certificates for each day during the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Class C Closing Date) and ending on, but excluding, the date of the earliest of such disposition, distribution, sale or Deemed Disposition Event with respect to such Series C Equipment Note or such Aircraft, as the case may be, on the principal amount of such Series C Equipment Note calculated pursuant to clause (B)(i), (ii), (iii) or (iv), as applicable, of the definition of Eligible C Pool Balance.

“ Class C Certificateholder ” means, at any time, any Certificateholder of one or more Class C Certificates.

“ Class C Certificates ” means the certificates issued by the Class C Trust, substantially in the form of Exhibit A to the Class C Trust Agreement, and authenticated by the Class C Trustee, representing Fractional Undivided Interests in the Class C Trust, and any certificates issued in exchange therefor or replacement thereof pursuant to the terms of the Class C Trust Agreement.

“ Class C Closing Date ” means May 10, 2018.

“ Class C Trust ” means the Spirit Airlines Pass Through Trust 2015-1C created and administered pursuant to the Class C Trust Agreement.

“ Class C Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2015-1C thereto, dated as of the date hereof, governing the creation and administration of the Spirit Airlines Pass Through Trust 2015-1C and the issuance of the Class C Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Class C Trustee ” means WTNA, not in its individual capacity except as expressly set forth in the Class C Trust Agreement, but solely as trustee under the Class C Trust Agreement, together with any successor trustee appointed pursuant thereto.

“ Closing Date ” means August 11, 2015.

“ Code ” means the Internal Revenue Code of 1986, as amended from time to time, and Treasury Regulations promulgated thereunder.

“ Collateral ” means, with respect to any Indenture, the “Collateral” referred to therein.

“ Collection Account ” means the Eligible Deposit Account established by the Subordination Agent pursuant to Section 2.02(a) in and from which the Subordination Agent shall make deposits and withdrawals in accordance with this Agreement.

“ Consent Notice ” has the meaning set forth in Section 3.05(d)(ii).

“ Consent Period ” has the meaning set forth in Section 3.05(d)(ii).

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	8

Exhibit 4.1

“ Controlling Party ” means the Person entitled to act as such pursuant to the terms of Section 2.06.

“ Corporate Trust Office ” means, with respect to any Trustee, the Subordination Agent or any Loan Trustee, the office of such Person in the city at which, at any particular time, its corporate trust business shall be principally administered.

“ Current Distribution Date ” means a Distribution Date specified as a reference date for calculating the Expected Distributions with respect to the Certificates of any Trust as of such Distribution Date.

“ Deemed Disposition Event ” means, in respect of any Equipment Note, the continuation of an Indenture Event of Default in respect of such Equipment Note without an Actual Disposition Event occurring in respect of such Equipment Note for a period of five years from the date of the occurrence of such Indenture Event of Default.

“ Delivery Period Termination Date ” has the meaning specified in the Note Purchase Agreement.

“ Deposit Agreement ” means, subject to Section 5 of the Note Purchase Agreement, with respect to any Class of Certificates (other than the Class C Certificates), the Deposit Agreement pertaining to such Class, dated as of August 11, 2015, between the Escrow Agent and the Depositary, as the same may be amended, modified or supplemented from time to time in accordance with the terms thereof.

“ Depositary ” means, subject to Section 5 of the Note Purchase Agreement, Natixis, as depositary under each Deposit Agreement.

“ Deposits ”, with respect to any Class of Certificates (other than the Class C Certificates), has the meaning set forth in the Deposit Agreement pertaining to such Class.

“ Designated Representatives ” means the Subordination Agent Representatives, the Trustee Representatives and the LP Representatives identified under Section 2.05.

“ Distribution Date ” means a Regular Distribution Date or a Special Distribution Date.

“ Dollars ” or “ $ ” means the lawful currency of the United States.

“ Downgrade Date ” has the meaning specified in Section 3.05(c)(i).

“ Downgrade Drawing ” has the meaning specified in Section 3.05(c)(iii).

“ Downgrade Event ” , with respect to any Liquidity Facility has the meaning specified in such Liquidity Facility.

“ Downgraded Facility ” has the meaning specified in Section 3.05(c)(i).

“ Drawing ” means an Interest Drawing, a Final Drawing, a Non-Extension Drawing, a Special Termination Drawing or a Downgrade Drawing, as the case may be.

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	9

Exhibit 4.1

“ DTC ” means The Depository Trust Company.

“ Eligible B Pool Balance ” means, as of any date of determination, the excess of (A) the Pool Balance of the Class B Certificates as of the immediately preceding Distribution Date (or, if such date of determination is on or before the first Distribution Date, the original aggregate face amount of the Class B Certificates) (after giving effect to distributions made on such date of determination) over (B) the sum of, with respect to each Series B Equipment Note, one of the following amounts, if applicable: (i) if there has previously been a sale or disposition by the applicable Loan Trustee of the applicable Aircraft for cash under the Indenture pursuant to which such Series B Equipment Note was issued, the outstanding principal amount of such Series B Equipment Note that remains unpaid as of such date of determination subsequent to such sale or disposition and after giving effect to any distributions of the proceeds of such sale or disposition applied under such Indenture to the payment of such Series B Equipment Note, (ii) if there has previously been an Event of Loss (as defined in such Indenture) with respect to the applicable Aircraft to which such Series B Equipment Note relates, the outstanding principal amount of such Series B Equipment Note that remains unpaid as of such date of determination subsequent to the scheduled date of mandatory redemption of such Series B Equipment Note following such Event of Loss and after giving effect to the distributions of any proceeds in respect of such Event of Loss applied under such Indenture to the payment of such Series B Equipment Note, (iii) if such Series B Equipment Note has previously been sold for cash by the Subordination Agent, the excess, if any, of (x) the outstanding amount of principal and interest as of the date of such sale by the Subordination Agent of such Series B Equipment Note over (y) the purchase price received with respect to such sale of such Series B Equipment Note for cash (net of any applicable costs and expenses of such sale) or (iv) if a Deemed Disposition Event has occurred with respect to such Series B Equipment Note, the outstanding principal amount of such Series B Equipment Note; provided , however , that if more than one of the clauses (i), (ii), (iii) and (iv) is applicable to any one Series B Equipment Note, only the amount determined pursuant to the clause that first became applicable shall be counted with respect to such Series B Equipment Note.

“ Eligible C Pool Balance ” means, as of any date of determination, the excess of (A) the Pool Balance of the Class C Certificates as of the immediately preceding Distribution Date (or, if such date of determination is on or before the first Distribution Date after the Class C Closing Date, the original aggregate face amount of the Class C Certificates) (after giving effect to distributions made on such date of determination) over (B) the sum of, with respect to each Series C Equipment Note, one of the following amounts, if applicable: (i) if there has previously been a sale or disposition by the applicable Loan Trustee of the applicable Aircraft for cash under the Indenture pursuant to which such Series C Equipment Note was issued, the outstanding principal amount of such Series C Equipment Note that remains unpaid as of such date of determination subsequent to such sale or disposition and after giving effect to any distributions of the proceeds of such sale or disposition applied under such Indenture to the payment of such Series C Equipment Note, (ii) if there has previously been an Event of Loss (as defined in such Indenture) with respect to the applicable Aircraft to which such Series C Equipment Note relates, the outstanding principal amount of such Series C Equipment Note that remains unpaid as of such date of determination subsequent to the scheduled date of mandatory redemption of such Series C Equipment Note following such Event of Loss and after giving effect to the distributions of any proceeds in respect of such Event of Loss applied under such Indenture to the payment of such Series C Equipment Note, (iii) if such Series C Equipment Note has

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	10

Exhibit 4.1

previously been sold for cash by the Subordination Agent, the excess, if any, of (x) the outstanding amount of principal and interest as of the date of such sale by the Subordination Agent of such Series C Equipment Note over (y) the purchase price received with respect to such sale of such Series C Equipment Note for cash (net of any applicable costs and expenses of such sale) or (iv) if a Deemed Disposition Event has occurred with respect to such Series C Equipment Note, the outstanding principal amount of such Series C Equipment Note; provided , however , that if more than one of the clauses (i), (ii), (iii) and (iv) is applicable to any one Series C Equipment Note, only the amount determined pursuant to the clause that first became applicable shall be counted with respect to such Series C Equipment Note.

“ Eligible Deposit Account ” means either (a) a segregated account with an Eligible Institution or (b) a segregated trust account with the corporate trust department of a depository institution organized under the laws of the United States of America or any one of the states thereof or the District of Columbia (or any U.S. branch of a foreign bank), having corporate trust powers and acting as trustee for funds deposited in such account, so long as any of the securities of such depository institution has a Long-Term Rating (or, if a Long-Term Rating is not available, its Short-Term Rating equivalent) of at least A- from either S&P or Fitch. An Eligible Deposit Account may be maintained with the Subordination Agent or a Liquidity Provider so long as the Subordination Agent or such Liquidity Provider is an Eligible Institution; provided that the Subordination Agent, in its individual capacity, or such Liquidity Provider shall have waived all rights of set-off and counterclaim with respect to such account.

“ Eligible Institution ” means (a) the corporate trust department of the Subordination Agent or any Trustee, as applicable, or (b) a depository institution organized under the laws of the United States of America or any one of the states thereof or the District of Columbia (or any U.S. branch of a foreign bank), which has a Long-Term Rating (or, if a Long-Term Rating is not available, its Short-Term Rating equivalent) of at least A- by either S&P or Fitch.

“ Eligible Investments ” means investments in (a) obligations of the United States government or agencies thereof, or obligations guaranteed by the United States government, having maturities no later than 365 days following the date of such investment, (b) open market commercial paper of any corporation incorporated under the laws of the United States or any state thereof having a Short-Term Rating of at least A-1 or its equivalent by S&P or at least F1 or its equivalent by Fitch having maturities no later than 365 days following the date of such investment, (c) certificates of deposit, time deposits, banker’s acceptances, commercial paper or other direct obligations of, or obligations guaranteed by, commercial banks organized under the laws of the United States or of any political subdivision thereof (or any United States branch of a foreign bank) having a combined capital and surplus in excess of $500,000,000 which banks or their holding companies have a Long-Term Rating of at least A- or its equivalent by either S&P or Fitch, having maturities no later than 365 days following the date of such investment; provided , however , that the aggregate amount at any one time invested in certificates of deposit issued by any one bank shall not be in excess of 5% of such bank’s capital and surplus, (d) Dollar denominated offshore certificates of deposit issued by, or offshore time deposits with, any commercial bank described in clause (c) or any subsidiary thereof having maturities no later than 365 days following the date of such investment, and (e) repurchase agreements with any financial institution having combined capital and surplus of at least $500,000,000 with any of the obligations described in clauses (a) through (d) as collateral having maturities no later than 365 days following the date of such investment. If none of the above investments is available, the entire amounts

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Exhibit 4.1

to be invested may be used to purchase Federal funds from an entity described in clause (c). All Eligible Investments must be held in an Eligible Deposit Account. Any of the investments described herein may be made through or with, as applicable, the bank acting as Trustee or its Affiliates.

“ Equipment Note Special Payment ” means a Special Payment on account of the redemption, purchase or prepayment of all of the Equipment Notes issued pursuant to an Indenture.

“ Equipment Notes ” means, at any time, the Series A Equipment Notes, the Series B Equipment Notes and the Series C Equipment Notes and in each case, any Equipment Notes issued in exchange therefor or replacement thereof pursuant to the terms of the Indentures.

“ Escrow Agent ” means Wilmington Trust Company, as escrow agent under each Escrow and Paying Agent Agreement, together with its successors in such capacity.

“ Escrow and Paying Agent Agreement ” means, with respect to any Class of Certificates (other than the Class C Certificates), the Escrow and Paying Agent Agreement pertaining to such Class dated as of August 11, 2015 between the Escrow Agent, the Underwriters, the Trustee for such Class and the Paying Agent, as the same may be amended, modified or supplemented from time to time in accordance with the terms thereof.

“ Escrow Receipts ” has the meaning assigned to such term in the Escrow and Paying Agent Agreement for the Class A Trust or Class B Trust, as applicable.

“ Excess Liquidity Obligations ” means, with respect to an Indenture, the amounts payable under clauses (a), (b), (c), (d), (e) and (f) of Section 2.14 of such Indenture.

“ Expected Distributions ” means, with respect to the Certificates of any Trust on any Current Distribution Date, the difference between (A) the Pool Balance of such Certificates as of the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date after the date of issuance of such Certificates, the original aggregate face amount of the Certificates of such Trust) and (B) the Pool Balance of such Certificates as of the Current Distribution Date calculated on the basis that (i) the principal of any Non-Performing Equipment Notes held in such Trust has been paid in full and such payments have been distributed to the holders of such Certificates, (ii) the principal of any Performing Equipment Notes held in such Trust has been paid when due (whether at stated maturity or upon prepayment or purchase or otherwise, but without giving effect to any Acceleration of Performing Equipment Notes) and such payments have been distributed to the holders of such Certificates and (iii) the principal of any Equipment Notes formerly held in such Trust that have been sold pursuant to the terms hereof has been paid in full and such payments have been distributed to the holders of such Certificates, but without giving effect to any reduction in the Pool Balance as a result of any distribution attributable to Deposits relating to such Trust occurring after the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, occurring after the initial issuance of the Certificates of such Trust). For purposes of calculating Expected Distributions with respect to the Certificates of any Trust, any Premium paid on the Equipment Notes held in such Trust which has not been distributed to the Certificateholders of such Trust (other than such Premium or a portion thereof applied to the payment of interest in respect of the Certificates

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	12

Exhibit 4.1

of such Trust or the reduction of the Pool Balance of such Trust) shall be added to the amount of such Expected Distributions.

“ Expiry Date ”, with respect to any Liquidity Facility, has the meaning specified in such Liquidity Facility.

“ Fee Letter ” means any fee letter entered into among the Subordination Agent, Spirit and a Liquidity Provider and “ Fee Letters ” has a correlative meaning.

“ Final Distributions ” means, with respect to the Certificates of any Trust on any Distribution Date, the sum of (x) the aggregate amount of all accrued and unpaid interest on such Certificates (excluding interest, if any, payable with respect to Deposits relating to such Trust) and (y) the Pool Balance of such Certificates as of the immediately preceding Distribution Date (less the amount of Deposits relating to such Trust as of such preceding Distribution Date other than any portion of such Deposits thereafter used to acquire Equipment Notes pursuant to the Original Note Purchase Agreement). For purposes of calculating Final Distributions with respect to the Certificates of any Trust, any Premium paid on the Equipment Notes held in such Trust which has not been distributed to the Certificateholders of such Trust (other than such Premium or a portion thereof applied to the payment of interest on the Certificates of such Trust or the reduction of the Pool Balance of such Trust) shall be added to the amount of such Final Distributions.

“ Final Drawing ” has the meaning specified in Section 3.05(i).

“ Final Legal Distribution Date ” means (i) with respect to the Class A Certificates, October 1, 2029 and (ii) with respect to the Class B Certificates, October 1, 2025 and (iii) with respect to the Class C Certificates, April 1, 2023.

“ First Amendment to Indenture ” means, with respect to each Aircraft, the First Amendment to Indenture and Security Agreement, dated as of the Class C Closing Date, between Spirit and the Loan Trustee relating to such Aircraft.

“ First Amendment to Participation Agreement ” means, with respect to each Aircraft, the First Amendment to Participation Agreement, dated as of the Class C Closing Date, among Spirit, the Loan Trustee, the Subordination Agent, the Trustees and WTNA relating to such Aircraft.

“Fitch” means Fitch Ratings, Inc.

“ Fractional Undivided Interest ” means the fractional undivided interest in a Trust that is represented by a Certificate relating to such Trust.

“ Indenture ” means each of the Indenture and Security Agreements entered into by the Loan Trustee and Spirit pursuant to the Original Note Purchase Agreement, in each case, as amended by the First Amendment to Indenture related thereto and as the same may be further amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Indenture Event of Default ” means, with respect to any Indenture, any Event of Default (as such term is defined in such Indenture) thereunder.

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Exhibit 4.1

“ Interest Drawing ” has the meaning specified in Section 3.05(a).

“ Interest Payment Date ” means, with respect to any Liquidity Facility, each date on which interest is due and payable under such Liquidity Facility on a Downgrade Drawing, Non-Extension Drawing, Special Termination Drawing or Final Drawing thereunder, other than any such date on which interest is due and payable under such Liquidity Facility only on an Applied Provider Advance or an Applied Special Termination Advance (as such terms are defined in such Liquidity Facility).

“ Investment Earnings ” means investment earnings on funds on deposit in the Trust Accounts net of losses and the Subordination Agent’s reasonable expenses in making such investments.

“ Lending Office ” has the meaning specified in the applicable Liquidity Facility.

“ Lien ” means any mortgage, pledge, lien, charge, claim, disposition of title, encumbrance, lease, sublease or security interest of any kind, including, without limitation, any of the foregoing arising under any conditional sales or other title retention agreement.

“ Liquidity Event of Default ”, with respect to any Liquidity Facility, has the meaning specified in such Liquidity Facility.

“ Liquidity Expenses ” means the Class A Liquidity Expenses and the Class B Liquidity Expenses.

“ Liquidity Facility ” means, at any time, the Class A Liquidity Facility or the Class B Liquidity Facility, as applicable.

“ Liquidity Obligations ” means the Class A Liquidity Obligations and the Class B Liquidity Obligations.

“ Liquidity Provider ” means, at any time, the Class A Liquidity Provider or the Class B Liquidity Provider, as applicable.

“ Loan Trustee ” means, with respect to any Indenture, the bank, trust company or other financial institution designated as loan trustee thereunder, and any successor to such loan trustee.

“ Long-Term Rating ” means, for any entity (a) in the case of Fitch, the long-term issuer default rating of such entity and (b) in the case of S&P, the long-term issuer credit rating of such entity.

“ LP Incumbency Certificate ” has the meaning specified in Section 2.05(c).

“ LP Representatives ” has the meaning specified in Section 2.05(c).

“ Majority in Interest of Noteholders ”, with respect to any Indenture, has the meaning specified in such Indenture.

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Exhibit 4.1

(2) the sum of the aggregate Note Target Price of such Equipment Notes and an amount equal to the Excess Liquidity Obligations in respect of the Indenture under which such Equipment Notes were issued.

“ Non-Controlling Party ” means, at any time, any Trustee, Liquidity Provider or other Person a party hereto, which, in each case, is not the Controlling Party at such time.

“ Non-Extended Facility ” has the meaning specified in Section 3.05(d).

“ Non-Extension Drawing ” has the meaning specified in Section 3.05(d).

“ Non-Performing Equipment Note ” means an Equipment Note issued pursuant to an Indenture that is not a Performing Equipment Note.

“ Note Purchase Agreement ” means the Note Purchase Agreement, dated as of August 11, 2015, among Spirit, the Class A Trustee, the Class B Trustee, the Escrow Agent, the Subordination Agent and the Paying Agent (the “ Original Note Purchase Agreement ”), as supplemented by the Joinder to Note Purchase Agreement, dated as of the Class C Closing Date, by the Class C Trustee in favor of Spirit, the Class A Trustee, the Class B Trustee, the Subordination Agent, the Escrow Agent and the Paying Agent, and as further amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Note Target Price ” means, for any Equipment Note issued under any Indenture, (i) the aggregate outstanding principal amount of such Equipment Note, plus (ii) the accrued and unpaid interest thereon, together with all other sums owing on or in respect of such Equipment Note under such Indenture (including, without limitation, enforcement costs incurred by the Subordination Agent in respect of such Equipment Note).

“ Notice Date” has the meaning specified in Section 3.05(d)(i).

“ Operative Agreements ” means this Agreement, the Liquidity Facilities, the Fee Letter(s), the Indentures, the Trust Agreements, the Participation Agreements, the Equipment Notes and the Certificates, together with all exhibits and schedules included with any of the foregoing.

“ Original Intercreditor Agreement ” has the meaning specified in the first recital hereto.

“ Original Note Purchase Agreement ” has the meaning specified in the definition of “ Note Purchase Agreement ”.

“ Outstanding ” means, when used with respect to each Class of Certificates, as of the date of determination, all Certificates of such Class theretofore authenticated and delivered under the related Trust Agreement, except:

(i) Certificates of such Class theretofore canceled by the Registrar (as defined in such Trust Agreement) or delivered to the Trustee thereunder or such Registrar for cancellation;

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Exhibit 4.1

Certificates as provided in Section 4.01 of such Trust Agreement, pending distribution of such money to such Certificateholders pursuant to such Final Distribution payment; and

(iii) Certificates of such Class in exchange for or in lieu of which other Certificates of such Class have been authenticated and delivered pursuant to such Trust Agreement;

provided , however , that in determining whether the holders of the requisite Fractional Undivided Interest of such Certificates have given any request, demand, authorization, direction, notice, consent or waiver hereunder, any Certificates owned by Spirit or any of its Affiliates shall be disregarded and deemed not to be Outstanding except that, in determining whether the Trustee of the applicable Trust shall be protected in relying upon any such request, demand, authorization, direction, notice, consent or waiver, only Certificates that such Trustee knows to be so owned shall be so disregarded. Notwithstanding the foregoing, (x) if Spirit and its Affiliates own 100% of the Certificates of any Class, such Certificates shall not be so disregarded and (y) if any amount of such Certificates owned by Spirit and its Affiliates have been pledged in good faith, such Certificates shall not be disregarded if the pledgee establishes to the satisfaction of the applicable Trustee the pledgee’s right so to act with respect to such Certificates and that the pledgee is not Spirit or any of its Affiliates.

“ Overdue Scheduled Payment ” means any Scheduled Payment which is not in fact received by the Subordination Agent within five days after the Scheduled Payment Date relating thereto.

“ Participation Agreement ” means each of the Participation Agreements entered into by Spirit, the Loan Trustee, the Subordination Agent, the Class A Trustee, the Class B Trustee and WTNA pursuant to the Original Note Purchase Agreement, in each case as amended by the First Amendment to Participation Agreement related thereto and as the same may be further amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Payees ” has the meaning specified in Section 2.04(c).

“ Paying Agent ” means WTNA, as paying agent under each Escrow and Paying Agent Agreement, together with its successors in such capacity.

“ Paying Agent Account ” has the meaning assigned to such term in the Escrow and Paying Agent Agreements.

“ Payment Default ”, with respect to any Indenture, has the meaning specified in such Indenture.

“ Performing Equipment Note ” means an Equipment Note issued pursuant to an Indenture with respect to which no Payment Default has occurred and is continuing (without giving effect to any Acceleration); provided that, in the event of a bankruptcy proceeding in which Spirit is a debtor under the Bankruptcy Code, (i) any payment default occurring before the date of the order for relief in such proceeding shall not be taken into consideration during the 60-Day Period (or such longer period as may apply under Section 1110(b) of the Bankruptcy Code) (the “ Section 1110 Period ”), (ii) any payment default occurring after the date of the order for relief in such proceeding shall not be taken into consideration if such payment default is cured under Section 1110(a)(2)(B) of the Bankruptcy Code before the later of 30 days after the

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Exhibit 4.1

date of such default or the expiration of the Section 1110 Period and (iii) any payment default occurring after the Section 1110 Period will not be taken into consideration if such payment default is cured before the end of the grace period, if any, set forth in the related Indenture.

“ Performing Note Deficiency ” means any time that less than 65% of the then aggregate outstanding principal amount of all Series A Equipment Notes and Series B Equipment Notes are Performing Equipment Notes.

“ Person ” means any individual, corporation, limited liability company, partnership, joint venture, association, joint-stock company, trust, trustee, unincorporated organization or government or any agency or political subdivision thereof.

“ Pool Balance ” means, with respect to the Certificates of any Class, as of any date, (i) the original aggregate face amount of the Certificates of such Class less (ii) the aggregate amount of all distributions made in respect of such Certificates of such Class or in respect of Deposits relating to such Class, other than distributions made as of such date in respect of interest or Premium or reimbursement of any costs or expenses incurred in connection therewith. The Pool Balance as of any Distribution Date with respect to each Class shall be computed after giving effect to any distribution with respect to unused Deposits relating to such Class, the payment of principal, if any, on the Equipment Notes or payment with respect to other Trust Property held in the related Trust and the distribution thereof to be made on such date.

“ Post-Default Appraisal ” has the meaning specified in Section 4.1(a)(iv).

“ Premium ” means any “ Make-Whole Amount ” as such term is defined in any Indenture.

“ Proceeding ” means any suit in equity, action at law or other judicial or administrative proceeding.

“ PTC Event of Default ” means, with respect to each Trust Agreement, the failure to distribute within 10 Business Days after the applicable Distribution Date: (i) the outstanding Pool Balance of the applicable Class of Certificates on the Final Legal Distribution Date for such Class or (ii) interest scheduled for distribution on such Certificates on any Distribution Date (unless, in the case of the Class A Trust Agreement or the Class B Trust Agreement, the Subordination Agent shall have made an Interest Drawing or a withdrawal from the Cash Collateral Account relating to a Liquidity Facility for such Class, with respect thereto in an aggregate amount sufficient to pay such interest and shall have distributed such amount to the Trustee entitled thereto).

“ Purchasers ” means the entities named as purchasers of the Class C Certificates in the Certificate Purchase Agreement.

“ Rating Agencies ” means, with respect to any Class of Certificates, collectively, at any time, each nationally recognized rating agency which shall have been requested by the Company to rate such Class of Certificates and which shall then be rating such Class of Certificates. The initial Rating Agencies will be (i) with respect to any Class of Certificates (other than the Class C Certificates), Fitch and S&P and (ii) with respect to the Class C Certificates, Fitch.

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Exhibit 4.1

“ Ratings Confirmation ” means, with respect to any action proposed to be taken, with respect to any Class of Certificates, a written confirmation from each of the Rating Agencies to the effect that such action would not result in (i) a reduction of the rating for such Class of Certificates below the then current rating for such Class of Certificates or (ii) a withdrawal or suspension of the rating of such Class of Certificates.

“ Refinancing Certificateholder ” has the meaning specified in Section 8.01(c), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include certificateholders of the new Class C Certificates issued in connection with the redemption of the Series C Equipment Notes and the issuance of new Series C Equipment Notes.

“ Refinancing Certificates ” has the meaning specified in Section 8.01(c), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the new Class C Certificates issued in connection with the redemption of the Series C Equipment Notes and the issuance of new Series C Equipment Notes.

“ Refinancing Equipment Notes ” has the meaning specified in Section 8.01(c), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the new Series C Equipment Notes issued in connection with the redemption of the Series C Equipment Notes and the issuance of such new Series C Equipment Notes.

“ Refinancing Trust ” has the meaning specified in Section 8.01(c), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the trust created pursuant to the pass through trust agreement relating to the new Class C Certificates issued in connection with the redemption of the Series C Equipment Notes and the issuance of new Series C Equipment Notes.

“ Refinancing Trust Agreement ” has the meaning specified in Section 8.01(c), provided , however, that for the purposes of each Trust Supplement referenced in the definitions of “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the pass through trust agreement relating to the new Class C Certificates issued in connection with the redemption of the Series C Equipment Notes and the issuance of new Series C Equipment Notes.

“ Refinancing Trustee ” has the meaning specified in Section 8.01(c).

“ Register ”, with respect to any Trust, has the meaning ascribed to such term in the Trust Agreement for such Trust.

“ Regular Distribution Dates ” means each April 1 and October 1, commencing on April 1, 2016; provided , however, that, if any such day shall not be a Business Day, the related distribution shall be made on the next succeeding Business Day without additional interest.

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Exhibit 4.1

“Replacement Airframe” , with respect to any Indenture, has the meaning specified in such Indenture.

“ Replacement Depositary ” has the meaning specified in the Note Purchase Agreement.

“ Replacement Liquidity Facility ” means, for any Liquidity Facility, an irrevocable revolving credit agreement (or agreements) in substantially the form of the replaced Liquidity Facility, including reinstatement provisions, or in such other form (which may include a letter of credit, surety bond, financial insurance policy or guaranty) as shall permit the Rating Agencies to confirm in writing their respective ratings then in effect for the Certificates of the Class with respect to which such Liquidity Facility was issued (before downgrading of such ratings, if any, as a result of the downgrading, if any, of the applicable Liquidity Provider), in a face amount (or in an aggregate face amount) equal to the applicable Required Amount and issued by a Person (or Persons) having the minimum Long-Term Rating specified by each Rating Agency as the applicable Threshold Rating for such Rating Agency and the applicable Class of Certificates. Without limitation of the form that a Replacement Liquidity Facility otherwise may have pursuant to the preceding sentence, a Replacement Liquidity Facility for any Class of Certificates may have a stated expiration date earlier than 15 days after the Final Legal Distribution Date of such Class of Certificates so long as such Replacement Liquidity Facility provides for a Non-Extension Drawing as contemplated by Section 3.05(d) hereof.

“ Replacement Liquidity Provider ” means a Person (or Persons) who issues a Replacement Liquidity Facility.

“ Required Amount ” means, with respect to each Liquidity Facility or the Cash Collateral Account for any Class, for any day, the sum of the aggregate amount of interest, calculated at the rate per annum equal to the Stated Interest Rate for the related Class of Certificates on the basis of a 360-day year comprised of twelve 30-day months, that would be distributable on such Class of Certificates on each of the three successive Regular Distribution Dates immediately following such day or, if such day is a Regular Distribution Date, on such day and the two succeeding Regular Distribution Dates, in each case calculated on the basis of the Pool Balance of such Class of Certificates on such day and without regard to expected future distributions of principal on such Class of Certificates.

“ Responsible Officer ” means (i) with respect to the Subordination Agent and each of the Trustees, any officer in the Corporate Trust Department or similar department of the Subordination Agent or such Trustee, as the case may be, or any other officer customarily performing functions similar to those performed by the persons who at the time shall be such officers or to whom any corporate trust matter is referred because of his knowledge of and familiarity with a particular subject, and (ii) with respect to any Liquidity Provider, any authorized officer of such Liquidity Provider.

“ S&P ” means Standard & Poor’s Ratings Services, a Standard & Poor’s Financial Services LLC business.

“ Scheduled Payment ” means, with respect to any Equipment Note, (i) any payment of principal or interest on such Equipment Note (other than an Overdue Scheduled Payment) or (ii) any distribution in respect of interest on such Equipment Note to the Certificateholders of Certificates of the

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Exhibit 4.1

corresponding Class of Certificates with funds drawn under the Liquidity Facility for such Class or withdrawn from the Cash Collateral Account for such Class, which payment in the case of clause (i) or clause (ii) represents an installment of principal on such Equipment Note at the stated maturity of such installment, or the payment of regularly scheduled interest accrued on the unpaid principal amount of such Equipment Note, or both; provided , however , that any payment of principal, Premium, if any, or interest resulting from the redemption, purchase or prepayment of any Equipment Note shall not constitute a Scheduled Payment.

“ Scheduled Payment Date ” means, with respect to any Scheduled Payment, the date on which such Scheduled Payment is scheduled to be made.

“ Section 2.04 Fraction ” means, with respect to any Special Distribution Date, a fraction, the numerator of which shall be the amount of principal of the applicable Series A Equipment Notes and Series B Equipment Notes being redeemed, purchased or prepaid on such Special Distribution Date, and the denominator of which shall be the aggregate unpaid principal amount of all Series A Equipment Notes and Series B Equipment Notes outstanding as of such Special Distribution Date immediately before giving effect to such redemption, purchase or prepayment.

“ Series A Equipment Notes ” means the equipment notes issued pursuant to each Indenture by Spirit and authenticated by the Loan Trustee thereunder, and designated “Series A Equipment Notes” thereunder, and any such Equipment Notes issued in exchange therefor or replacement thereof pursuant to the terms of such Indenture.

“ Series B Equipment Notes ” means the equipment notes issued pursuant to each Indenture by Spirit and authenticated by the Loan Trustee thereunder, and designated “Series B Equipment Notes” thereunder, and any such Equipment Notes issued in exchange therefor or replacement thereof pursuant to the terms of such Indenture.

“ Series C Equipment Notes ” means the equipment notes issued pursuant to each Indenture by Spirit and authenticated by the Loan Trustee thereunder, and designated “Series C Equipment Notes” thereunder, and any such Equipment Notes issued in exchange therefor or replacement thereof pursuant to the terms of such Indenture.

“ Short-Term Rating ” means, for any entity, (a) in the case of Fitch, the short-term issuer default rating of such entity and (b) in the case of S&P, the short-term issuer credit rating of such entity.

“ Special Distribution Date ” means, with respect to any Special Payment, the Business Day chosen by the Subordination Agent pursuant to Section 2.04(a) for the distribution of such Special Payment in accordance with this Agreement.

“ Special Payment ” means any payment (other than a Scheduled Payment) in respect of, or any proceeds of, any Equipment Note or Collateral.

“ Special Payments Account ” means the Eligible Deposit Account created pursuant to Section 2.02(a) as a sub-account to the Collection Account.

“ Special Termination Drawing ” has the meaning assigned to such term in Section 3.05(k).

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Exhibit 4.1

“ Special Termination Notice ”, with respect to any Liquidity Facility has the meaning assigned to such term (if such term is used therein) in such Liquidity Facility.

“ Spirit ” means Spirit Airlines, Inc., a Delaware corporation, and its successors and permitted assigns.

“ Spirit Bankruptcy Event ” means the occurrence and continuation of any of the following:

(a) Spirit consents to the appointment of or the taking of possession by a receiver, trustee or liquidator of itself or of a substantial part of its property, admits in writing its inability to pay its debts generally as they come due or makes a general assignment for the benefit of creditors;

(b) Spirit files a voluntary petition in bankruptcy or a voluntary petition or an answer seeking reorganization, liquidation or other relief as a debtor in a case under any bankruptcy laws or insolvency laws (as in effect at such time) or an answer admitting the material allegations of a petition filed against Spirit as a debtor in any such case, or Spirit seeks relief as a debtor by voluntary petition, answer or consent, under the provisions of any other bankruptcy or other similar law providing for the reorganization or winding-up of corporations (as in effect at such time), or Spirit seeks an agreement, composition, extension or adjustment with its creditors under such laws; or

(c) an order, judgment or decree is entered by any court of competent jurisdiction appointing, without the consent of Spirit, a receiver, trustee or liquidator of Spirit or sequestering any substantial part of its property, or granting any other relief in respect of Spirit as a debtor under any bankruptcy laws or insolvency laws (as in effect at such time), and any such order, judgment or decree of appointment or sequestration remains in force undismissed, unstayed and unvacated for a period of 90 days after the date of entry thereof; or

(d) a petition against Spirit as a debtor in a case under the federal bankruptcy laws or other insolvency laws (as in effect at such time) is filed and not withdrawn or dismissed within 90 days thereafter, or if, under the provisions of any law providing for reorganization or winding-up of corporations that applies to Spirit, any court of competent jurisdiction assumes jurisdiction, custody or control of Spirit or of any substantial part of its property and such jurisdiction, custody or control remains in force unrelinquished, unstayed and unterminated for a period of 90 days.

“ Spirit Provisions ” has the meaning specified in Section 8.01(a).

“ Stated Amount ”, with respect to any Liquidity Facility, means the Maximum Commitment (as defined in such Liquidity Facility) of the applicable Liquidity Provider thereunder.

“ Stated Expiration Date ” has the meaning specified in Section 3.05(d).

“ Stated Interest Rate ” means (i) with respect to the Class A Certificates, 4.100% per annum, (ii) with respect to the Class B Certificates, 4.450% per annum, and (iii) with respect to the Class C Certificates, 4.930% per annum.

“ Subordination Agent ” has the meaning specified in the introductory paragraph to this Agreement.

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Exhibit 4.1

“ Subordination Agent Incumbency Certificate ” has the meaning specified in Section 2.05(a).

“ Subordination Agent Representatives ” has the meaning specified in Section 2.05(a).

“Substitute Airframe” , with respect to any Indenture, has the meaning specified in such Indenture.

“ Tax ” and “ Taxes ” means all governmental fees (including, without limitation, license, filing and registration fees) and all taxes (including, without limitation, franchise, excise, stamp, value added, income, gross receipts, sales, use and property taxes), withholdings, assessments, levies, imposts, duties or charges, of any nature whatsoever, together with any related penalties, fines, additions to tax or interest thereon imposed, withheld, levied or assessed by any country, taxing authority or governmental subdivision thereof or therein or by any international authority, including any taxes imposed on any Person as a result of such Person being required to collect and pay over withholding taxes.

“ Termination Notice ” has the meaning specified in the Liquidity Facility.

“ Threshold Rating ” means (i) for the Class A Trust, a Long-Term Rating of BBB+ as determined by each of S&P and Fitch and (ii) for the Class B Trust, a Long-Term Rating of BBB as determined by each of S&P and Fitch.

“ Treasury Regulations ” means regulations, including proposed or temporary regulations, promulgated under the Code. References herein to specific provisions of proposed or temporary regulations shall include analogous provisions of final Treasury Regulations or other successor Treasury Regulations.

“ Triggering Event ” means (x) the occurrence of an Indenture Event of Default under all of the Indentures resulting in a PTC Event of Default with respect to the most senior Class of Certificates then Outstanding, (y) the Acceleration of all of the outstanding Equipment Notes; provided that, with respect to the period prior to the Delivery Period Termination Date, the aggregate principal balance of such Equipment Notes is in excess of $350,000,000 or (z) the occurrence of a Spirit Bankruptcy Event.

“ Trust ” means the Class A Trust, the Class B Trust or the Class C Trust, as applicable.

“ Trust Accounts ” has the meaning specified in Section 2.02(a).

“ Trust Agreement ” means the Class A Trust Agreement, the Class B Trust Agreement or the Class C Trust Agreement, as applicable.

“ Trust Property ”, with respect to any Trust, has the meaning specified in the Trust Agreement for such Trust.

“ Trust Supplement ” means an agreement supplemental to the Basic Agreement pursuant to which (i) a separate trust is created for the benefit of the holders of Certificates of a Class, (ii) the issuance of the Certificates of a Class representing Fractional Undivided Interests in such trust is authorized and (iii) the terms of the Certificates of such Class are established, as such agreement may from time to time be supplemented, amended or otherwise modified.

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Exhibit 4.1

“ Trustee ” means the Class A Trustee, the Class B Trustee or the Class C Trustee, as applicable.

“ Trustee Incumbency Certificate ” has the meaning specified in Section 2.05(b).

“ Trustee Representatives ” has the meaning specified in Section 2.05(b).

“ Unapplied Provider Advance ” has the meaning specified in the applicable Liquidity Facility.

“ Underwriters ” means Citigroup Global Markets, Inc., Morgan Stanley & Co. LLC and Credit Suisse Securities (USA) LLC.

“ Underwriting Agreement ” means the Underwriting Agreement, dated July 28, 2015 among the Underwriters and Spirit, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ United States ” means the United States of America.

“ Withdrawal Notice ” has the meaning specified in Section 3.05(d)(ii).

“ Written Notice ” means, from the Subordination Agent, any Trustee or Liquidity Provider, a written instrument executed by the Designated Representative of such Person. An invoice delivered by a Liquidity Provider pursuant to Section 3.01 in accordance with its normal invoicing procedures shall constitute Written Notice under such Section.

“ WTNA ” has the meaning specified in the introductory paragraph of this Agreement.

Article II

TRUST ACCOUNTS; CONTROLLING PARTY

Section 2.01 Agreement to Terms of Subordination; Payments from Monies Received Only . (a) Each Trustee hereby (i) acknowledges and agrees to the terms of subordination and distribution set forth in this Agreement in respect of each Class of Certificates and (ii) agrees to enforce such provisions and cause all payments in respect of the Equipment Notes held by the Subordination Agent and the Liquidity Facilities to be applied in accordance with the terms of this Agreement. In addition, each Trustee hereby agrees to cause the Equipment Notes purchased by the related Trust to be registered in the name of the Subordination Agent or its nominee, as agent and trustee for such Trustee, to be held in trust by the Subordination Agent solely for the purpose of facilitating the enforcement of the subordination and other provisions of this Agreement.

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	23

Exhibit 4.1

hereof. Each Trustee and the Subordination Agent hereby agrees, and each Certificateholder, by its acceptance of a Certificate, and each Liquidity Provider, by entering into the Liquidity Facility to which it is a party, has agreed to look solely to such amounts to the extent available for distribution to it as provided in this Agreement, the relevant Deposits or the applicable Trust Agreement, as the case may be, and that none of the Trustees, the Loan Trustees or the Subordination Agent is personally liable to any of them for any amounts payable or any liability arising under this Agreement, any Trust Agreement, any Liquidity Facility or such Certificate, except (in the case of the Subordination Agent) as expressly provided herein or (in the case of the Trustees) as expressly provided herein and in each Trust Agreement or (in the case of the Loan Trustees) as expressly provided in any Operative Agreement.

(c) Notwithstanding anything to the contrary in this Agreement and in the other Operative Agreements, the Certificates do not represent indebtedness of the related Trust, and references in this Agreement and the Operative Agreements to accrued interest or principal amounts payable on the Certificates of any Class are included only for computational purposes. For purposes of such computations, the Certificates of any Class shall be deemed to be comprised of interest and principal components, with the principal component deemed to be the Pool Balance, and the interest component deemed to equal interest accruing at the Stated Interest Rate for such Class of Certificates from the later of (1) the date of the issuance thereof and (2) the most recent but preceding Distribution Date to which such interest was distributed to, but excluding, the applicable date of determination, such interest to be considered payable in arrears and to be calculated on the basis of a 360-day year comprised of twelve 30-day months.

Section 2.02 Trust Accounts . (a) Upon the execution of this Agreement, the Subordination Agent shall establish and maintain in its name (i) the Collection Account as an Eligible Deposit Account, bearing a designation clearly indicating that the funds deposited therein are held in trust for the benefit of the Trustees, the Certificateholders and the Liquidity Providers, and (ii) as a sub-account in the Collection Account, the Special Payments Account as an Eligible Deposit Account, bearing a designation clearly indicating that the funds deposited therein are held in trust for the benefit of the Trustees, the Certificateholders and the Liquidity Providers. The Subordination Agent shall establish and maintain the Cash Collateral Accounts pursuant to and under the circumstances set forth in Section 3.05(f). Upon such establishment and maintenance under Section 3.05(f), the Cash Collateral Accounts shall, together with the Collection Account, constitute the “Trust Accounts” hereunder. Without limiting the foregoing, all monies credited to the Trust Accounts shall be, and shall remain, the property of the relevant Trust(s).

(b) Funds on deposit in the Trust Accounts shall be invested and reinvested by the Subordination Agent in Eligible Investments selected by Spirit or its designated representative if such investments are reasonably available and have maturities no later than the earlier of (i) 90 days following the date of such investment and (ii) the Business Day immediately preceding the Regular Distribution Date or the date of the related distribution pursuant to Section 2.04, as the case may be, next following the date of such investment; provided , however , that, following the making of a Non-Extension Drawing under any Liquidity Facility, the Subordination Agent shall invest and reinvest the amounts in the applicable Cash Collateral Account in Eligible Investments pursuant to the written instructions of the Liquidity Provider funding such Drawing, and provided further , however, that upon the occurrence and during the continuation of a Triggering Event, the Subordination Agent shall invest and reinvest the amounts on deposit in the Trust Accounts (other than amounts in the Cash Collateral Accounts as a result of a Non-Extension Drawing,

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Exhibit 4.1

which shall be governed by the foregoing proviso) in Eligible Investments in accordance with the written instructions of the Controlling Party. Unless otherwise expressly provided in this Agreement (including, without limitation, with respect to Investment Earnings on amounts on deposit in the Cash Collateral Accounts, Section 3.05(f)), any Investment Earnings shall be deposited in the Collection Account when received by the Subordination Agent and shall be applied by the Subordination Agent in the same manner as the other amounts on deposit in the Collection Account are to be applied. The Subordination Agent’s reasonable fees and expenses actually incurred in making such investments and any losses incurred in such investments shall be charged against the principal amount invested. The Subordination Agent shall not be liable for any loss resulting from any investment, reinvestment or liquidation required to be made under this Agreement other than by reason of its willful misconduct or negligence. Eligible Investments and any other investment required to be made hereunder shall be held to their maturities except that any such investment may be sold (without regard to its maturity) by the Subordination Agent without instructions whenever such sale is necessary to make a distribution required under this Agreement. Uninvested funds held hereunder shall not earn or accrue interest.

(c) The Subordination Agent shall possess all right, title and interest in all funds on deposit from time to time in the Trust Accounts and in all proceeds thereof (including all income thereon, except as otherwise expressly provided herein with respect to Investment Earnings). The Trust Accounts shall be held in trust by the Subordination Agent under the sole dominion and control of the Subordination Agent for the benefit of the applicable Trustee, the applicable Certificateholders and the applicable Liquidity Provider, as the case may be. If, at any time, any of the Trust Accounts ceases to be an Eligible Deposit Account, the Subordination Agent shall within 10 Business Days (or such longer period, not to exceed 30 calendar days, to which a Rating Agency may consent) establish a new Collection Account, Special Payments Account or Cash Collateral Account, as the case may be, as an Eligible Deposit Account and shall transfer any cash and/or any investments to such new Collection Account, Special Payments Account or Cash Collateral Account, as the case may be. So long as the Subordination Agent is an Eligible Institution, the Trust Accounts shall be maintained with it as Eligible Deposit Accounts.

Section 2.03 Deposits to the Collection Account and Special Payments Account . (a) The Subordination Agent shall, upon receipt thereof, deposit in the Collection Account all Scheduled Payments received by it (other than any Scheduled Payment which by the express terms hereof is to be deposited to a Cash Collateral Account).

(b) The Subordination Agent shall, on each day when one or more Special Payments are made to the Subordination Agent as holder of the Equipment Notes, deposit in the Special Payments Account the aggregate amount of such Special Payments.

Section 2.04 Distributions of Special Payments . (a) Notice of Special Payment . Except as provided in Section 2.04(c) below, upon receipt by the Subordination Agent, as registered holder of the Equipment Notes, of any notice of a Special Payment (or, in the absence of any such notice, upon receipt by the Subordination Agent of a Special Payment), the Subordination Agent shall promptly give notice thereof to each Trustee and the Liquidity Providers. The Subordination Agent shall promptly calculate the amount of the proceeds of any redemption, purchase or prepayment of any Equipment Note or the amount of any Overdue Scheduled Payment or the proceeds of Equipment Notes or Collateral, as the case may be,

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Exhibit 4.1

comprising such Special Payment under the applicable Indenture or Indentures and shall promptly send to each Trustee and the Liquidity Providers a Written Notice of such amount and the amount allocable to each Trust. Such Written Notice shall also set the distribution date for such Special Payment (a “ Special Distribution Date ”), which shall be the Business Day which immediately follows the later to occur of (x) the 15th day after the date of such Written Notice and (y) the date the Subordination Agent has received or expects to receive such Special Payment. Amounts on deposit in the Special Payments Account shall be distributed in accordance with Sections 2.04(b) and 2.04(c) and Article III hereof, as applicable.

For the purposes of the application of any Special Payment in respect of any Equipment Note to be distributed on any Special Distribution Date in accordance with Section 3.02 hereof, so long as no Indenture Event of Default shall have occurred and be continuing under any Indenture:

(i) clause “second” thereof shall be deemed to read as follows: “second, accrued and unpaid Liquidity Expenses then overdue plus an amount equal to all accrued and unpaid Liquidity Expenses not yet overdue multiplied by the Section 2.04 Fraction shall be distributed to the Liquidity Providers pro rata on the basis of the amount of the Liquidity Expenses owed to each Liquidity Provider”;

(ii) clause “third” thereof shall be deemed to read as follows: “third, (i) such amount as shall be required to pay accrued and unpaid interest then overdue on all Liquidity Obligations (at the rate, or in the amount, provided in the applicable Liquidity Facility) plus an amount equal to the amount of accrued and unpaid interest on the Liquidity Obligations not yet overdue multiplied by the Section 2.04 Fraction, and (ii) if one or more Special Termination Drawings have been made under the Liquidity Facilities and have not been converted into a Final Drawing, the outstanding amount of such Special Termination Drawings, shall be distributed to the Liquidity Providers, pro rata on the basis of the amounts owed to each Liquidity Provider”;

(iii) clause “seventh” thereof shall be deemed to read as follows: “seventh, such amount as shall be required to pay accrued, due and unpaid interest at the Stated Interest Rate on the outstanding Pool Balance of the Class A Certificates, together with (without duplication) any other accrued and unpaid interest at the Stated Interest Rate on the outstanding principal amount of the Series A Equipment Notes held in the Class A Trust being redeemed, purchased or prepaid, in each case excluding interest, if any, payable with respect to Deposits relating to the Class A Trust shall be paid to the Class A Trustee”;

(iv) clause “eighth” thereof shall be deemed to read as follows: “eighth, such amount as shall be required to pay any accrued, due and unpaid Class B Adjusted Interest to the holders of the Class B Certificates (excluding interest, if any, payable with respect to Deposits relating to the Class B Trust) shall be paid to the Class B Trustee”;

(v) clause “ninth” thereof shall be deemed to read as follows: “ninth, such amount as shall be required to pay any accrued, due and unpaid Class C Adjusted Interest to the holders of the Class C Certificates shall be paid to the Class C Trustee”;

(vi) clause “eleventh” thereof shall be deemed to read as follows: “eleventh, such amount as shall be required to pay in full accrued, due and unpaid interest at the Stated Interest Rate on the outstanding Pool Balance of the Class B Certificates which was not previously paid pursuant to clause “eighth” above

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Exhibit 4.1

to the holders of the Class B Certificates, together with (without duplication) any other accrued and unpaid interest at the Stated Interest Rate on the outstanding principal amount of the Series B Equipment Notes held in the Class B Trust and being redeemed, purchased or prepaid, in each case excluding interest, if any, payable with respect to Deposits relating to the Class B Trust, shall be paid to the Class B Trustee”; and

(vii) clause “thirteenth” thereof shall be deemed to read as follows: “thirteenth, such amount as shall be required to pay in full accrued, due and unpaid interest at the Stated Interest Rate on the outstanding Pool Balance of the Class C Certificates which was not previously paid pursuant to clause “ninth” above to the holders of the Class C Certificates, together with (without duplication) any other accrued and unpaid interest at the Stated Interest Rate on the outstanding principal amount of the Series C Equipment Notes held in the Class C Trust and being redeemed, purchased or prepaid shall be paid to the Class C Trustee”.

(b) Investment of Amounts in Special Payments Account . Any amounts on deposit in the Special Payments Account prior to the distribution thereof pursuant to Section 2.04 or 3.02 shall be invested in accordance with Section 2.02(b). Investment Earnings on such investments shall be distributed in accordance with Article III hereof.

(c) Certain Payments . Except for amounts constituting Liquidity Obligations which shall be distributed as provided in Section 3.02, the Subordination Agent will distribute promptly upon receipt thereof (i) any indemnity payment or expense reimbursement received by it from Spirit in respect of any Trustee, any Liquidity Provider, the Paying Agent, the Depositary or the Escrow Agent (collectively, the “ Payees ”) and (ii) any compensation received by it from Spirit under any Operative Agreement in respect of any Payee, directly to the Person entitled thereto, provided that if such Payee has previously received from the Collection Account such payment, compensation or reimbursement, then the Subordination Agent shall deposit such amount in the Collection Account.

Section 2.05 Designated Representatives . (a) With the delivery of this Agreement, the Subordination Agent shall furnish to each Liquidity Provider and each Trustee, and from time to time thereafter may furnish to each Liquidity Provider and each Trustee, at the Subordination Agent’s discretion, or upon any Liquidity Provider’s or any Trustee’s request (which request shall not be made more than one time in any 12-month period), a certificate (a “ Subordination Agent Incumbency Certificate ”) of a Responsible Officer of the Subordination Agent certifying as to the incumbency and specimen signatures of the officers of the Subordination Agent and the attorney-in-fact and agents of the Subordination Agent (the “ Subordination Agent Representatives ”) authorized to give Written Notices on behalf of the Subordination Agent hereunder. Until each Liquidity Provider and Trustee receives a subsequent Subordination Agent Incumbency Certificate, it shall be entitled to rely on the last Subordination Agent Incumbency Certificate delivered to it hereunder.

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Exhibit 4.1

“ Trustee Representatives ”) authorized to give Written Notices on behalf of such Trustee hereunder. Until the Subordination Agent receives a subsequent Trustee Incumbency Certificate from a Trustee, it shall be entitled to rely on the last Trustee Incumbency Certificate with respect to such Trustee delivered to it hereunder.

(c) With the delivery of this Agreement, each Liquidity Provider shall furnish to the Subordination Agent, and from time to time thereafter may furnish to the Subordination Agent, at such Liquidity Provider’s discretion, or upon the Subordination Agent’s request (which request shall not be made more than one time in any 12-month period), a certificate (with respect to each such Liquidity Provider, an “ LP Incumbency Certificate ”) of a Responsible Officer of such Liquidity Provider certifying as to the incumbency and specimen signatures of the officers of such Liquidity Provider and the attorney-in-fact and agents of such Liquidity Provider (with respect to each such Liquidity Provider, the “LP Representatives” and, together with the Subordination Agent Representatives and the Trustee Representatives, the “ Designated Representatives ”) authorized to give Written Notices on behalf of such Liquidity Provider hereunder. Until the Subordination Agent receives a subsequent LP Incumbency Certificate from a Liquidity Provider, it shall be entitled to rely on the last LP Incumbency Certificate with respect to such Liquidity Provider delivered to it hereunder.

Section 2.06 Controlling Party . (a) Subject to Section 8.01(b), the Trustees and the Liquidity Providers hereby agree that, with respect to any Indenture at any given time, the Loan Trustee thereunder will be directed: (i) so long as no Indenture Event of Default has occurred and is continuing thereunder, in taking, or refraining from taking, any action under such Indenture or with respect to the Equipment Notes issued thereunder by a Majority in Interest of Noteholders of such Equipment Notes ( provided that, for so long as the Subordination Agent is the registered holder of such Equipment Notes, the Subordination Agent shall act with respect to this clause (i) in accordance with the directions of the Trustees (in the case of each such Trustee, with respect to the Equipment Notes issued under such Indenture and held as Trust Property of such Trust) constituting, in the aggregate, directions with respect to an outstanding principal amount of such Equipment Notes that, if held by such Trustees directly, would make such Trustees a Majority in Interest of Noteholders), and (ii) after the occurrence and during the continuance of an Indenture Event of Default thereunder, in taking, or refraining from taking, any action under such Indenture or with respect to such Equipment Notes issued thereunder, including exercising remedies thereunder (including Accelerating the Equipment Notes issued thereunder or foreclosing the Lien created thereunder on the Aircraft securing such Equipment Notes), by the Controlling Party.

(b) Subject to paragraph (c) below, the “Controlling Party” shall be (w) the Class A Trustee and (x) upon payment of Final Distributions to the holders of Class A Certificates, but prior to payment of Final Distributions to the holders of Class B Certificates, the Class B Trustee, and (y) upon payment of Final Distributions to the holders of the Class A Certificates and the Class B Certificates, but prior to payment of Final Distributions to the holders of the Class C Certificates, the Class C Trustee, and (z) upon payment of Final Distributions to the holders of the Class A Certificates, the Class B Certificates and the Class C Certificates, but, if any class or classes of Additional Certificates are outstanding, prior to payment of Final Distributions to the holders of the most senior, in priority of payment of “Expected Distributions” under this Agreement, class of Additional Certificates, the Additional Trustee for the Additional Trust related to such most senior class of Additional Certificates. For purposes of giving effect

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Exhibit 4.1

to the provisions of Section 2.06(a) and this Section 2.06(b), the Trustees (other than the Controlling Party) irrevocably agree (and the Certificateholders (other than the Certificateholders represented by the Controlling Party) shall be deemed to agree by virtue of their purchase of Certificates) that the Subordination Agent, as record holder of the Equipment Notes, and subject always to the provisions of Section 2.06(a) and Article VIII, shall exercise its voting rights in respect of the Equipment Notes so held by the Subordination Agent as directed by the Controlling Party and any vote so exercised shall be binding upon the Trustees and all Certificateholders.

The Subordination Agent shall give Written Notice to all of the other parties to this Agreement promptly upon a change in the identity of the Controlling Party. Each of the parties hereto agrees that it shall not exercise any of the rights of the Controlling Party at such time as it is not the Controlling Party hereunder; provided , however , that nothing herein contained shall prevent or prohibit any Non-Controlling Party from exercising such rights as shall be specifically granted to such Non-Controlling Party hereunder and under the other Operative Agreements.

(c) Notwithstanding the foregoing, at any time after 18 months from the earliest to occur of (i) the date on which the entire Available Amount as of such date under any Liquidity Facility shall have been drawn (for any reason other than a Downgrade Drawing or a Non-Extension Drawing but including a Final Drawing, a Special Termination Drawing or a Downgrade Drawing or Non-Extension Drawing that has been converted into a Final Drawing under such Liquidity Facility) and remains unreimbursed, (ii) the date on which the entire amount of any Downgrade Drawing or Non-Extension Drawing under any Liquidity Facility shall have become and remain “Applied Downgrade Advances” or “Applied Non-Extension Advances”, as the case may be, under and as defined in such Liquidity Facility and (iii) the date on which all Equipment Notes under all Indentures shall have been Accelerated ( provided that (x) with respect to the period prior to the Delivery Period Termination Date, such Equipment Notes have an aggregate outstanding principal balance in excess of $350,000,000 and (y) in the event of a bankruptcy proceeding under the Bankruptcy Code in which Spirit is a debtor, any amounts payable in respect of Equipment Notes which have become immediately due and payable by declaration or otherwise shall not be considered Accelerated for purposes of this sub-clause (iii) until the expiration of the 60-Day Period or such longer period as may apply under Section 1110(a)(2)(B) or Section 1110(b) of the Bankruptcy Code), the Liquidity Provider with the greatest amount of unreimbursed Liquidity Obligations owed to it (so long as such Liquidity Provider has not defaulted in its obligation to make any Drawing under its Liquidity Facility) shall have the right to elect, by Written Notice to the Subordination Agent and each of the Trustees, to become the Controlling Party hereunder with respect to any Indenture at any time from and including the last day of such 18-month period.

(d) [Reserved].

(e) The exercise of remedies by the Controlling Party under this Agreement shall be expressly limited by Sections 4.01(a)(ii) and 4.01(a)(iii) hereof.

(f) The Controlling Party shall not be entitled to require or obligate any Non-Controlling Party to provide funds necessary to exercise any right or remedy hereunder.

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Exhibit 4.1

(g) Notwithstanding anything contained herein, neither the Controlling Party nor the Subordination Agent shall be authorized or empowered to do anything that would cause any Trust to fail to qualify as a “grantor trust” for federal income tax purposes.

Article III

RECEIPT, DISTRIBUTION AND APPLICATION OF AMOUNTS RECEIVED

Section 3.01 Written Notice of Distribution . (a) No later than 3:00 P.M. (New York City time) on the Business Day immediately preceding each Distribution Date, each of the following Persons shall deliver to the Subordination Agent a Written Notice setting forth the following information as at the close of business on such Business Day:

(i) With respect to the Class A Certificates, the Class A Trustee shall separately set forth the amounts to be paid in accordance with clause “first” (to reimburse payments made by such Trustee or the Class A Certificateholders, as the case may be, pursuant to subclause (ii) or (iv) of clause “first”) of Section 3.02 hereof, subclauses (ii) and (iii) of clause “sixth” of Section 3.02 hereof and clauses “seventh” and “tenth” of Section 3.02 hereof;

(ii) With respect to the Class B Certificates, the Class B Trustee shall separately set forth the amounts to be paid in accordance with clause “first” (to reimburse payments made by such Trustee or the Class B Certificateholders, as the case may be, pursuant to subclause (ii) or (iv) of clause “first”) of Section 3.02 hereof, subclauses (ii) and (iii) of clause “sixth” of Section 3.02 hereof and clauses “eighth”, “eleventh” and “twelfth” of Section 3.02 hereof;

(iii) With respect to the Class C Certificates, the Class C Trustee shall separately set forth the amounts to be paid in accordance with clause “first” (to reimburse payments made by such Trustee or the Class C Certificateholders, as the case may be, pursuant to subclause (ii) or (iv) of clause “first”) of Section 3.02 hereof, subclauses (ii) and (iii) of clause “sixth” of Section 3.02 hereof and clauses “ninth”, “thirteenth” and “fourteenth” of Section 3.02 hereof;

(iv) With respect to each Liquidity Facility, the Liquidity Provider thereunder shall separately set forth the amounts to be paid to it in accordance with subclauses (iii) and (iv) of clause “first” of Section 3.02 hereof, clause “second” of Section 3.02 hereof, clause “third” of Section 3.02 hereof, clause “fourth” of Section 3.02 hereof and clause “fifth” of Section 3.02 hereof; and

(v) Each Trustee shall set forth the amounts to be paid in accordance with clause “sixth” of Section 3.02 hereof.

(b) At such time as a Trustee or a Liquidity Provider shall have received all amounts owing to it (and, in the case of a Trustee, the Certificateholders for which it is acting) pursuant to Section 3.02 hereof, as applicable, and, in the case of a Liquidity Provider, its commitment or obligations under the related Liquidity Facility shall have terminated or expired, such Person shall, by a Written Notice, so inform the Subordination Agent, Spirit and each other party to this Agreement.

(c) As provided in Section 6.05, the Subordination Agent shall be fully protected in relying on any of the information set forth in a Written Notice provided by any Trustee or any Liquidity

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Exhibit 4.1

Provider pursuant to paragraphs (a) and (b) above and shall have no independent obligation to verify, calculate or recalculate any amount set forth in any Written Notice delivered in accordance with such paragraphs.

(d) Any Written Notice delivered by a Trustee, a Liquidity Provider or the Subordination Agent, as applicable, pursuant to Section 3.01, if made prior to 10:00 A.M. (New York City time) on any Business Day shall be effective on the date delivered (or if delivered later on a Business Day or if delivered on a day that is not a Business Day shall be effective as of the next Business Day). Subject to the terms of this Agreement, the Subordination Agent shall as promptly as practicable comply with any such instructions; provided , however , that any transfer of funds pursuant to any instruction received after 10:00 A.M. (New York City time) on any Business Day may be made on the next succeeding Business Day.

(e) In the event the Subordination Agent shall not receive from any Person any information set forth in paragraph (a) above which is required to enable the Subordination Agent to make a distribution to such Person pursuant to Section 3.02 hereof, the Subordination Agent shall request such information and, failing to receive any such information, the Subordination Agent shall not make such distribution(s) to such Person. In such event, the Subordination Agent shall make distributions pursuant to clauses “first” through “fourteenth” of Section 3.02 to the extent it shall have sufficient information to enable it to make such distributions, and shall continue to hold any funds remaining on the terms hereof, including Section 2.02(b), after making such distributions, until the Subordination Agent shall receive all necessary information to enable it to distribute any funds so withheld, and upon receipt of the information necessary to distribute any funds so withheld, the Subordination Agent shall distribute such funds.

(f) On such dates (but not more frequently than monthly) as any Liquidity Provider or any Trustee shall request, but in any event automatically at the end of each calendar quarter, the Subordination Agent shall send to such party a written statement reflecting all amounts on deposit with the Subordination Agent pursuant to Section 3.01(e).

The notices required under this Section 3.01(a) may be in the form of a schedule or similar document provided to the Subordination Agent by the parties referenced therein or by any one of them, which schedule or similar document may state that, unless there has been a prepayment of the Equipment Notes, such schedule or similar document is to remain in effect until any substitute notice or amendment shall be given to the Subordination Agent by the party providing such notice.

Section 3.02 Distribution of Amounts on Deposit in the Collection Account . Except as otherwise provided in Sections 2.04, 3.01(e), 3.03, 3.05(b) and 3.05(l), amounts on deposit in the Collection Account (including amounts on deposit in the Special Payments Account) shall be promptly distributed on each Regular Distribution Date (or, in the case of any amount described in Sections 2.04(a) or 2.04(b), on the Special Distribution Date thereof) in the following order of priority and in accordance with the information provided to the Subordination Agent pursuant to Section 3.01(a):

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Exhibit 4.1

in the protection of, or the realization of the value of, the Equipment Notes or any Collateral, shall be applied by the Subordination Agent in reimbursement of such costs and expenses, (ii) any Trustee for any amounts of the nature described in clause (i) above actually incurred by it under the applicable Trust Agreement (to the extent not previously reimbursed), shall be distributed to such Trustee, (iii) any Liquidity Provider for any amounts of the nature described in clause (i) above actually incurred by it (to the extent not previously reimbursed), shall be distributed to such Liquidity Provider, and (iv) any Liquidity Provider or any Certificateholder for payments, if any, made by it to the Subordination Agent or any Trustee in respect of amounts described in clause (i) above actually incurred by it (to the extent not previously reimbursed) (collectively, the “ Administration Expenses ”), shall be distributed to such Liquidity Provider or the applicable Trustee for the account of such Certificateholder, in each such case, pro rata on the basis of all amounts described in clauses (i) through (iv) above;

second , such amount as shall be required to pay all accrued and unpaid Liquidity Expenses owed to each Liquidity Provider (other than amounts distributed pursuant to clause “first” of this Section 3.02) shall be distributed to the Liquidity Providers pro rata on the basis of the amount of Liquidity Expenses owed to each Liquidity Provider;

third , (i) such amount as shall be required to pay the aggregate amount of accrued and unpaid interest on all Liquidity Obligations (at the rate, or in the amount, provided in the applicable Liquidity Facility) shall be distributed to the Liquidity Providers pro rata on the basis of the amounts owed to each Liquidity Provider, and, after giving effect to clause (i) above, (ii) if one or more Special Termination Drawings have been made under the Liquidity Facilities that have not been converted into a Final Drawing, the outstanding amount of such Special Termination Drawings shall be distributed to the Liquidity Providers pro rata on the basis of the amounts owed to each Liquidity Provider;

fourth , such amount as shall be required (A) if any Cash Collateral Account had been previously funded as provided in Section 3.05(f), unless (i) on such Distribution Date a Performing Note Deficiency exists and a Liquidity Event of Default shall have occurred and be continuing with respect to the relevant Liquidity Facility or (ii) a Final Drawing shall have occurred with respect to such Liquidity Facility or an Interest Drawing for such Liquidity Facility shall have been converted into a Final Drawing, to fund such Cash Collateral Account up to its Required Amount shall be deposited in such Cash Collateral Account, (B) if any Liquidity Facility shall become a Downgraded Facility or a Non-Extended Facility at a time when unreimbursed Interest Drawings under such Liquidity Facility have reduced the Available Amount thereunder to zero, unless (i) on such Distribution Date a Performing Note Deficiency exists and a Liquidity Event of Default shall have occurred and be continuing with respect to the relevant Liquidity Facility or (ii) a Final Drawing shall have occurred with respect to such Liquidity Facility or an Interest Drawing for such Liquidity Facility shall have been converted into a Final Drawing, to fund the related Cash Collateral Account up to its Required Amount shall be deposited in such Cash Collateral Account, and (C) if, with respect to any particular Liquidity Facility neither subclause (A) nor subclause (B) of this clause “fourth” is applicable, to pay or reimburse the Liquidity Provider in respect of such Liquidity Facility in an amount equal to the outstanding amount of all Liquidity Obligations then due under such

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	32

Exhibit 4.1

Liquidity Facility (other than amounts distributed pursuant to clauses “first”, “second” or “third” of this Section 3.02), pro rata on the basis of the amounts of all such fundings and/or unreimbursed Liquidity Obligations payable to each Liquidity Provider;

fifth , if, with respect to any particular Liquidity Facility, any amounts are to be distributed pursuant to either subclause (A) or (B) of clause “fourth” above, then the Liquidity Provider with respect to such Liquidity Facility shall be paid the excess of (x) the aggregate outstanding amount of unreimbursed Advances (whether or not then due) under such Liquidity Facility over (y) the Required Amount for the relevant Cash Collateral Account without duplication of any amounts distributed pursuant to clauses “first”, “second”, “third”, and “fourth” of this Section 3.02, pro rata on the basis of such amounts in respect of such Liquidity Provider;

sixth , such amount as shall be required to reimburse or pay (i) the Subordination Agent for any Tax (other than Taxes imposed on compensation paid hereunder), expense, fee, charge or other loss incurred by, or any other amount payable to, the Subordination Agent in connection with the transactions contemplated hereby (to the extent not previously reimbursed), shall be applied by the Subordination Agent in reimbursement of such amount, (ii) each Trustee for any Tax (other than Taxes imposed on compensation paid under the applicable Trust Agreement), expense, fee, charge or other loss incurred by, or any other amount payable to, such Trustee under the applicable Trust Agreements (to the extent not previously reimbursed), shall be distributed to such Trustee, and (iii) each Certificateholder for payments, if any, made by it pursuant to Section 5.02 hereof in respect of amounts described in clause (i) above (without duplication of any amounts distributed pursuant to subclause (iv) of clause “first” of this Section 3.02) shall be distributed to the applicable Trustee for the account of such Certificateholder, in each such case, pro rata, without duplication, on the basis of all amounts described in clauses (i) through (iii) above;

seventh , such amount as shall be required to pay in full accrued and unpaid interest at the Stated Interest Rate on the Pool Balance of the Class A Certificates (excluding interest, if any, payable with respect to Deposits relating to the Class A Trust) shall be distributed to the Class A Trustee;

eighth , such amount as shall be required to pay unpaid Class B Adjusted Interest to the holders of the Class B Certificates (excluding interest, if any, payable with respect to Deposits relating to the Class B Trust) shall be distributed to the Class B Trustee;

ninth , such amount as shall be required to pay unpaid Class C Adjusted Interest to the holders of the Class C Certificates shall be distributed to the Class C Trustee;

tenth , such amount as shall be required to pay in full Expected Distributions to the holders of the Class A Certificates on such Distribution Date shall be distributed to the Class A Trustee;

eleventh , such amount as shall be required to pay in full accrued and unpaid interest at the Stated Interest Rate on the Pool Balance of the Class B Certificates which was not previously paid pursuant to clause “eighth” above to the holders of the Class B Certificates (excluding interest, if any, payable with respect to Deposits relating to the Class B Trust) shall be distributed to the Class B Trustee;

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	33

Exhibit 4.1

twelfth , such amount as shall be required to pay in full Expected Distributions to the holders of the Class B Certificates on such Distribution Date shall be distributed to the Class B Trustee;

thirteenth , such amount as shall be required to pay in full accrued and unpaid interest at the Stated Interest Rate on the Pool Balance of the Class C Certificates which was not previously paid pursuant to clause “ninth” above to the holders of the Class C Certificates shall be distributed to the Class C Trustee;

fourteenth , such amount as shall be required to pay in full Expected Distributions to the holders of the Class C Certificates on such Distribution Date shall be distributed to the Class C Trustee; and

fifteenth , the balance, if any, of any such amount remaining thereafter shall be held in the Collection Account for later distribution in accordance with this Article III.

With respect to clauses “first” and “sixth” above, no amounts shall be reimbursable to the Subordination Agent, any Trustee, any Liquidity Provider or any Certificateholder for any payments made by any such Person in connection with any Equipment Note that is no longer held by the Subordination Agent (to the extent that such payments relate to periods after such Equipment Note ceases to be held by the Subordination Agent).

Section 3.03 Other Payments . (a) Any payments received by the Subordination Agent for which no provision as to the application thereof is made in this Agreement shall be distributed by the Subordination Agent (i) in the order of priority specified in Section 3.02 hereof and (ii) to the extent received or realized at any time after the Final Distributions for each Class of Certificates have been made, in the manner provided in clause “first” of Section 3.02 hereof.

(b) Notwithstanding the priority of payments specified in Section 3.02, in the event any Investment Earnings on amounts on deposit in any Cash Collateral Account resulting from an Unapplied Provider Advance or Special Termination Advance are deposited in the Collection Account or the Special Payments Account, such Investment Earnings shall be used to pay interest payable in respect of such Unapplied Provider Advance or such Special Termination Advance, as the case may be, to the extent of such Investment Earnings.

(c) If the Subordination Agent receives any Scheduled Payment after the Scheduled Payment Date relating thereto, but prior to such payment becoming an Overdue Scheduled Payment, then the Subordination Agent shall deposit such Scheduled Payment in the Collection Account and promptly distribute such Scheduled Payment in accordance with the priority of distributions set forth in Section 3.02; provided that, for the purposes of this Section 3.03(c) only, each reference in clauses “tenth”, “twelfth” and “ fourteenth” of Section 3.02 to “Distribution Date” shall be deemed to refer to such Scheduled Payment Date.

Section 3.04 Payments to the Trustees and the Liquidity Providers . Any amounts distributed hereunder to any Liquidity Provider shall be paid by wire transfer of funds to the account that such Liquidity Provider shall provide to the Subordination Agent. The Subordination Agent shall provide a Written Notice of any such transfer to the applicable Liquidity Provider at the time of such transfer. Any

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	34

Exhibit 4.1

amounts distributed hereunder by the Subordination Agent to any Trustee that is not the same institution as the Subordination Agent shall be paid to such Trustee by wire transfer of funds at the account such Trustee shall provide to the Subordination Agent.

Section 3.05 Liquidity Facilities . (a) Interest Drawings . If on any Distribution Date, after giving effect to the subordination provisions of this Agreement, the Subordination Agent shall not have sufficient funds for the payment of any amounts due and owing in respect of accrued interest on the Class A Certificates or the Class B Certificates (at the Stated Interest Rate for such Class of Certificates) (other than any amount of interest which was due and payable in respect of the Class A Certificates or the Class B Certificates on such Distribution Date but which remains unpaid due to the failure of the Depositary to pay any amount of accrued interest on the relevant Deposits on such Distribution Date), then, prior to 12:30 p.m. (New York City time) on such Distribution Date, (i) the Subordination Agent shall request a drawing (each such drawing, an “ Interest Drawing ”) under the Liquidity Facility with respect to such Class of Certificates in an amount equal to the lesser of (x) an amount sufficient to pay the amount of such accrued interest shortfall (at the applicable Stated Interest Rate for such Class of Certificates) and (y) the Available Amount under such Liquidity Facility, and (ii) the Subordination Agent shall upon receipt of such amount pay such amount to the Trustee with respect to each such Class of Certificates in payment of such accrued interest shortfall.

(c) Downgrade Drawings . (i) Each Liquidity Provider will promptly, but in any event within 10 days of the occurrence of a Downgrade Event with respect to it (the date of such occurrence, the “ Downgrade Date ”), deliver notice to the Subordination Agent and Spirit of the occurrence of such Downgrade Event and the Downgrade Date therefor. After the occurrence of a Downgrade Event with respect to any Liquidity Provider, each Liquidity Facility provided by such Liquidity Provider shall become a “ Downgraded Facility ” on the 35th day after the related Downgrade Date, unless, not later than such 35th day (or, if earlier, the expiration date of such Downgraded Facility), the Rating Agency whose downgrading of such Liquidity Provider resulted in such Downgrade Event shall have provided a written confirmation to the effect that the occurrence of such Downgrade Event will not result in the downgrading, withdrawal or suspension of the ratings then issued by such Rating Agency of the related Class of Certificates. Notwithstanding the foregoing, if at any time after the occurrence of such Downgrade Event, such Liquidity Provider notifies the Subordination Agent in writing that no such confirmation will be provided by such Rating Agency, each Liquidity Facility provided by such Liquidity Provider shall become a Downgraded Facility as of the date of such notice to the Subordination Agent.

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	35

Exhibit 4.1

the Liquidity Provider under such Downgraded Facility or Spirit may arrange for a Replacement Liquidity Provider to issue and deliver a Replacement Liquidity Facility to the Subordination Agent in accordance with Section 3.05(e).

(ii) If a Downgraded Facility has not been replaced by a Replacement Liquidity Facility in accordance with Section 3.05(c)(ii), the Subordination Agent shall, on the 35th day referred to in Section 3.05(c)(ii) (or if such 35th day is not a Business Day, on the next succeeding Business Day) (or, if earlier, the expiration date of such Downgraded Facility), request a drawing in accordance with and to the extent permitted by such Downgraded Facility (such drawing, a “ Downgrade Drawing ”) of the Available Amount thereunder. Amounts drawn pursuant to a Downgrade Drawing shall be maintained and invested as provided in Section 3.05(f) hereof. Subject to Section 3.05(e)(iii), the applicable Liquidity Provider may also arrange for a Replacement Liquidity Provider to issue and deliver a Replacement Liquidity Facility at any time after such Downgrade Drawing so long as such Downgrade Drawing has not been reimbursed in full to such Liquidity Provider.

(iii) For the avoidance of doubt, the provisions of this Section 3.05(c) shall apply to each occurrence of a Downgrade Event with respect to a Liquidity Provider, regardless of whether or not one or more Downgrade Events have occurred prior thereto and whether or not any confirmation by a Rating Agency specified in Section 3.05(c)(i) has been obtained with respect to any prior occurrence of a Downgrade Event.

(iv) If, at any time after making a Downgrade Drawing, the applicable Liquidity Provider satisfies the applicable Threshold Rating and delivers written notice to such effect to the Subordination Agent and Spirit, as of the second Business Day following receipt of such notice, (A) such Downgraded Facility shall cease to be a Downgraded Facility, (B) the Subordination Agent shall withdraw the unapplied amount of such Downgrade Drawing on deposit in the applicable Cash Collateral Account and reimburse such amount to such Liquidity Provider, (C) any applied amount of such Downgrade Drawing shall be deemed to have been converted to an Interest Drawing as of such date in accordance with the applicable Liquidity Facility, (D) the obligations of such Liquidity Provider shall be reinstated in accordance with the applicable Liquidity Facility, and (E) the proviso in the definition of Available Amount shall no longer apply to such Downgrade Advance.

(d) Non-Extension Drawings . If any Liquidity Facility with respect to any Class of Certificates is scheduled to expire on a date (the “ Stated Expiration Date ”) prior to the date that is 15 days after the Final Legal Distribution Date for such Class of Certificates, then the following provisions shall apply:

(i) In the case of either initial Liquidity Facility or any other Liquidity Facility having extension provisions identical to those set forth in Section 2.10 of either initial Liquidity Facility, then, if before the 25th day prior to any anniversary of the Closing Date (such 25th day, the “ Notice Date ”), the Liquidity Provider shall have advised the Subordination Agent and Spirit that such Liquidity Facility shall not be extended beyond the immediately following anniversary date of the Closing Date and on or before the Notice Date such Liquidity Facility shall not have been replaced in accordance with Section 3.05(e), the Subordination Agent shall, on the Notice Date (or as soon thereafter as possible but prior to the date of expiration of the expiring Liquidity Facility (a “ Non-Extended Facility ”), in accordance with the terms of

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	36

Exhibit 4.1

such Non-Extended Facility, request a drawing under such Non-Extended Facility (such drawing, a “ Non-Extension Drawing ”) of the Available Amount thereunder.

(ii) In the case of any other Liquidity Facility, no earlier than the 60th day and no later than the 40th day prior to the then applicable Stated Expiration Date, the Subordination Agent shall request in writing that such Liquidity Provider extend the Stated Expiration Date to the earlier of (i) the date that is 15 days after the Final Legal Distribution Date for such Class of Certificates and (ii) the date that is the day immediately preceding the 364th day after the last day of the Consent Period (unless the obligations of such Liquidity Provider thereunder are earlier terminated in accordance with such Liquidity Facility). Whether or not the applicable Liquidity Provider has received a request from the Subordination Agent, such Liquidity Provider shall by notice (the “ Consent Notice ”) to the Subordination Agent, during the period commencing on the date that is 60 days prior to the then effective Stated Expiration Date (or if earlier, the date of such Liquidity Provider’s receipt of such request, if any, from the Subordination Agent) and ending on the date that is 25 days prior to such Stated Expiration Date (the “ Consent Period ”) advise the Subordination Agent whether, in its sole discretion, it agrees to so extend the Stated Expiration Date; provided, that such extension shall not be effective with respect to such Liquidity Provider if, by notice (the “ Withdrawal Notice ”) to the Subordination Agent prior to the end of the Consent Period, such Liquidity Provider revokes its Consent Notice. If a Liquidity Provider advises the Subordination Agent on or before the end of the Consent Period that such Stated Expiration Date shall not be so extended or fails to irrevocably and unconditionally advise the Subordination Agent on or before the end of the Consent Period that such Stated Expiration Date shall be so extended or gives a Withdrawal Notice to the Subordination Agent prior to the end of the Consent Period (and, in each case, if such Liquidity Provider shall not have been replaced in accordance with Section 3.05(e)), the Subordination Agent shall, on the date on which the Consent Period ends (or as soon as possible thereafter but prior to the Stated Expiration Date), in accordance with and to the extent permitted by the terms of the Non-Extended Facility, request a Non-Extension Drawing under such Non-Extended Facility of the Available Amount thereunder.

(iii) Amounts drawn pursuant to a Non-Extension Drawing shall be maintained and invested in accordance with Section 3.05(f).

(e) Issuance of Replacement Liquidity Facility . (i) Subject to Section 3.05(e)(iii) and the agreements, if any, in the applicable Fee Letter, at any time, Spirit may, at its option, with cause or without cause, arrange for a Replacement Liquidity Facility to replace any Liquidity Facility for any Class of Certificates (including any Replacement Liquidity Facility provided pursuant to Section 3.05(e)(ii)); provided , however , that if the initial Liquidity Provider is replaced (including as a result of issuance of Refinancing Certificates in respect of the Class B Certificates) it shall be replaced with respect to all Liquidity Facilities under which it is a Liquidity Provider; provided , further , that the initial Liquidity Provider shall not be replaced by Spirit as a Liquidity Provider with respect to such Liquidity Facility without the consent of such Liquidity Provider during the period prior to the third anniversary of the Closing Date unless (A) there shall have become due to such initial Liquidity Provider, or such initial Liquidity Provider shall have demanded, amounts pursuant to Section 3.01 or 3.03 of any applicable Liquidity Facility or Spirit determines in good faith that there is a substantial likelihood that such initial Liquidity Provider will have the right to claim any such amounts (unless such initial Liquidity Provider waives, in writing, any right it may have to claim such amounts), which determination shall be set forth in a certificate delivered by Spirit to such initial

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	37

Exhibit 4.1

Liquidity Provider setting forth the basis for such determination, (B) it shall become unlawful or impossible for such initial Liquidity Provider to maintain or fund its LIBOR Advances as described in Section 3.10 of any Liquidity Facility, (C) any Liquidity Facility of such initial Liquidity Provider shall become a Downgraded Facility or a Non-Extended Facility or a Downgrade Drawing or a Non-Extension Drawing shall have occurred under any Liquidity Facility of such initial Liquidity Provider or (D) such initial Liquidity Provider shall have breached any of its payment (including, without limitation, funding) obligations under any Liquidity Facility in respect of which it is the Liquidity Provider. If such Replacement Liquidity Facility is provided at any time after a Downgrade Drawing, a Non-Extension Drawing or a Special Termination Drawing has been made, all funds on deposit in the relevant Cash Collateral Account resulting from such Downgrade Drawing, Non-Extension Drawing or Special Termination Drawing will be returned to the Liquidity Provider being replaced.

(i) If any Liquidity Provider shall determine not to extend its Liquidity Facility in accordance with Section 3.05(d), then such Liquidity Provider may, at its option, arrange for a Replacement Liquidity Facility to replace such Liquidity Facility during the period no earlier than 40 days and no later than 25 days prior to the then effective Stated Expiration Date of such Liquidity Facility. At any time after a Non-Extension Drawing has been made under any Liquidity Facility, the Liquidity Provider thereunder may, at its option and its own expense, arrange for a Replacement Liquidity Facility to replace the Liquidity Facility under which such Non-Extension Drawing has been made.

(ii) No Replacement Liquidity Facility arranged by Spirit or a Liquidity Provider in accordance with clause (i) or (ii) above or pursuant to Section 3.05(c), respectively, shall become effective and no such Replacement Liquidity Facility shall be deemed a “Liquidity Facility” under the Operative Agreements, unless and until (A) each of the conditions referred to in sub-clauses (iv)(x) and (z) below shall have been satisfied, (B) if such Replacement Liquidity Facility shall materially adversely affect the rights, remedies, interests or obligations of the Class A Certificateholders or the Class B Certificateholders under any of the Operative Agreements, the applicable Trustee shall have consented, in writing, to the execution and issuance of such Replacement Liquidity Facility and (C) in the case of a Replacement Liquidity Facility arranged by a Liquidity Provider under Section 3.05(e)(ii) or pursuant to Section 3.05(c), such Replacement Liquidity Facility is reasonably acceptable to Spirit.

(iii) In connection with the issuance of each Replacement Liquidity Facility, the Subordination Agent shall (x) prior to the issuance of such Replacement Liquidity Facility, obtain written confirmation from each Rating Agency to the effect that such Replacement Liquidity Facility will not cause a reduction, withdrawal or suspension of any rating then in effect for the related Class of Certificates by such Rating Agency (without regard to any downgrading of any rating of the Liquidity Provider being replaced pursuant to Section 3.05(c)), (y) pay all Liquidity Obligations then owing to the replaced Liquidity Provider (which payment shall be made first from available funds in the applicable Cash Collateral Account as described in Section 3.05(f), and thereafter from any other available source, including, without limitation, a drawing under the Replacement Liquidity Facility) and (z) cause the issuer of the Replacement Liquidity Facility to deliver the Replacement Liquidity Facility to the Subordination Agent, together with a legal opinion opining that such Replacement Liquidity Facility is an enforceable obligation of such Replacement Liquidity Provider.

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	38

Exhibit 4.1

(iv) Upon satisfaction of the conditions set forth in clauses (iii) and (iv) of this Section 3.05(e) with respect to a Replacement Liquidity Facility, (1) the replaced Liquidity Facility shall terminate, (2) the Subordination Agent shall, if and to the extent so requested by Spirit or the Liquidity Provider being replaced, execute and deliver any certificate or other instrument required in order to terminate the replaced Liquidity Facility, shall surrender the replaced Liquidity Facility to the Liquidity Provider being replaced and shall execute and deliver the Replacement Liquidity Facility and any associated Fee Letter, (3) each of the parties hereto shall enter into any amendments to this Agreement necessary to give effect to (a) the replacement of the applicable Liquidity Provider with the applicable Replacement Liquidity Provider and (b) the replacement of the applicable Liquidity Facility with the applicable Replacement Liquidity Facility, and (4) the applicable Replacement Liquidity Provider shall be deemed to be a Liquidity Provider with the rights and obligations of a Liquidity Provider hereunder and under the other Operative Agreements and such Replacement Liquidity Facility shall be deemed to be a Liquidity Facility hereunder and under the other Operative Agreements.

(v) Spirit shall be responsible for all fees and expenses related to its arranging a Replacement Liquidity Facility pursuant to Section 3.05(e)(i) (including a Replacement Liquidity Facility for a Non-Extended Facility) but excluding (x) any replacement at any time, whether arranged by Spirit or the Liquidity Provider being replaced, of a Downgraded Facility or (y) any replacement, whether arranged by Spirit or the Liquidity Provider being replaced, following any event described in clause (D) of the second proviso to the first sentence of Section 3.05(e)(i), in each case regardless of whether such replacement occurs before or after the third anniversary of the Closing Date. The Liquidity Provider being replaced shall be responsible for all fees and expenses related to its arranging a Replacement Liquidity Facility pursuant to Section 3.05(e)(ii), or any replacement pursuant to clause (x) or (y) of the immediately preceding sentence, provided , that the fees and expenses for which such Liquidity Provider is responsible shall in any case not include any ongoing fees or expenses of the Replacement Liquidity Provider (for the avoidance of doubt, in each case, such fees and expenses shall include upfront fees, structuring fees or similar fees (if any) payable to the Replacement Liquidity Provider.

(f) Cash Collateral Accounts; Withdrawals; Investments . In the event the Subordination Agent shall draw all Available Amounts under the Class A Liquidity Facility or the Class B Liquidity Facility pursuant to Section 3.05(c), 3.05(d), 3.05(i) or 3.05(k), or in the event amounts are to be deposited in the Class A Cash Collateral Account or the Class B Cash Collateral Account pursuant to subclause (A) or (B) of clause “fourth” of Section 3.02, amounts so drawn or to be deposited, as the case may be, shall be deposited by the Subordination Agent in the Class A Cash Collateral Account or the Class B Cash Collateral Account, as applicable. All amounts on deposit in each Cash Collateral Account shall be invested and reinvested in Eligible Investments in accordance with Section 2.02(b).

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	39

Exhibit 4.1

applied on such Interest Payment Date (or Special Distribution Date, as the case may be) in accordance with Section 3.02 or 3.03 (as applicable). The Subordination Agent shall deliver a written statement to Spirit and each Liquidity Provider one day prior to each Interest Payment Date and Special Distribution Date setting forth the aggregate amount of Investment Earnings held in the Cash Collateral Accounts as of such date. In addition, from and after the date funds are so deposited, the Subordination Agent shall make withdrawals from such accounts as follows:

(i) on each Distribution Date, the Subordination Agent shall, to the extent it shall not have received funds to pay accrued and unpaid interest due and owing on the Class A Certificates (at the Stated Interest Rate for the Class A Certificates) (other than any amount of interest which was due and payable in respect of the Class A Certificates on such Distribution Date but which remains unpaid due to the failure of the Depositary to pay any amount of accrued interest on the relevant Deposits on such Distribution Date) after giving effect to the subordination provisions of this Agreement, withdraw from the Class A Cash Collateral Account, and pay to the Class A Trustee, an amount equal to the lesser of (x) an amount necessary to pay accrued and unpaid interest (at the Stated Interest Rate for the Class A Certificates) on the Class A Certificates (other than any amount of interest which was due and payable in respect of the Class A Certificates on such Distribution Date but which remains unpaid due to the failure of the Depositary to pay any amount of accrued interest on the relevant Deposits on such Distribution Date) and (y) the amount on deposit in the Class A Cash Collateral Account;

(ii) on each Distribution Date, the Subordination Agent shall, to the extent it shall not have received funds to pay accrued and unpaid interest due and owing on the Class B Certificates (at the Stated Interest Rate for the Class B Certificates) (other than any amount of interest which was due and payable in respect of the Class B Certificates on such Distribution Date but which remains unpaid due to the failure of the Depositary to pay any amount of accrued interest on the relevant Deposits on such Distribution Date) after giving effect to the subordination provisions of this Agreement, withdraw from the Class B Cash Collateral Account, and pay to the Class B Trustee, an amount equal to the lesser of (x) an amount necessary to pay accrued and unpaid interest (at the Stated Interest Rate for the Class B Certificates) on such Class B Certificates (other than any amount of interest which was due and payable in respect of the Class B Certificates on such Distribution Date but which remains unpaid due to the failure of the Depositary to pay any amount of accrued interest on the relevant Deposits on such Distribution Date) and (y) the amount on deposit in the Class B Cash Collateral Account;

(iii) on each date on which the Pool Balance of the Class A Trust shall have been reduced by payments made to the Class A Certificateholders pursuant to Section 3.02 hereof or pursuant to Section 2.03 of the Escrow and Paying Agent Agreement for such Class, the Subordination Agent shall withdraw from the Class A Cash Collateral Account such amount as is necessary so that, after giving effect to the reduction of the Pool Balance on such date (and any reduction in the amounts on deposit in the Class A Cash Collateral Account resulting from a prior withdrawal of amounts on deposit in the Class A Cash Collateral Account on such date) and any transfer of Investment Earnings from such Cash Collateral Account to the Collection Account or the Special Payments Account on such date, an amount equal to the sum of the Required Amount (with respect to the Class A Liquidity

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	40

Exhibit 4.1

Facility) plus (if on a Distribution Date not coinciding with an Interest Payment Date) Investment Earnings on deposit in such Cash Collateral Account (after giving effect to any such transfer of Investment Earnings) will remain on deposit in the Class A Cash Collateral Account and shall first, pay such withdrawn amount to the Class A Liquidity Provider until the Class A Liquidity Obligations owing to the Class A Liquidity Provider shall have been paid in full, and second, deposit any remaining withdrawn amount in the Collection Account;

(iv) on each date on which the Pool Balance of the Class B Trust shall have been reduced by payments made to the Class B Certificateholders pursuant to Section 3.02 hereof or pursuant to Section 2.03 of the Escrow and Paying Agent Agreement for such Class, the Subordination Agent shall withdraw from the Class B Cash Collateral Account such amount as is necessary so that, after giving effect to the reduction of the Pool Balance on such date (and any reduction in the amounts on deposit in the Class B Cash Collateral Account resulting from a prior withdrawal of amounts on deposit in the Class B Cash Collateral Account on such date) and any transfer of Investment Earnings from such Cash Collateral Account to the Collection Account or the Special Payments Account on such date, an amount equal to the sum of the Required Amount (with respect to the Class B Liquidity Facility) plus (if on a Distribution Date not coinciding with an Interest Payment Date) Investment Earnings on deposit in such Cash Collateral Account (after giving effect to any such transfer of Investment Earnings) will remain on deposit in the Class B Cash Collateral Account and shall first, pay such withdrawn amount to the Class B Liquidity Provider until the Class B Liquidity Obligations owing to such Liquidity Provider shall have been paid in full, and second, deposit any remaining withdrawn amount in the Collection Account;

(v) if a Replacement Liquidity Facility for any relevant Class of Certificates shall be delivered to the Subordination Agent following the date on which funds have been deposited into the Cash Collateral Account for such Class of Certificates, the Subordination Agent shall withdraw all amounts remaining on deposit in such Cash Collateral Account and shall pay such amounts to the replaced Liquidity Provider, if any, until all Liquidity Obligations owed to such Person shall have been paid in full, and deposit any remaining amount in the Collection Account;

(vi) if the Liquidity Provider with respect to a Downgraded Facility satisfies the applicable Threshold Rating and delivers written notice to such effect to the Subordination Agent and Spirit, on the second Business Day following receipt of such notice, the Subordination Agent shall withdraw all amounts remaining on deposit in the applicable Cash Collateral Account constituting the unapplied amount of any Downgrade Drawing and shall pay such amounts to such Liquidity Provider and the obligations of such Liquidity Provider shall be reinstated in accordance with the applicable Liquidity Facility; and

(vii) following (x) the payment of Final Distributions or (y) the Final Legal Distribution Date with respect to any Class of Certificates covered by a Liquidity Facility, on the date on which the Subordination Agent shall have been notified by the Liquidity Provider for such Class of Certificates that the Liquidity Obligations owed to such Liquidity Provider have been paid in full, or, if earlier, the first Business Day after such Final Legal Distribution Date, the Subordination Agent

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



	41

Exhibit 4.1

shall withdraw all amounts on deposit in the Cash Collateral Account in respect of such Class of Certificates, if any, and shall deposit such amounts in the Collection Account.

(g) Reinstatement . With respect to any Interest Drawing under the Liquidity Facility for any relevant Trust, upon the reimbursement of the applicable Liquidity Provider for all or any part of the amount of such Interest Drawing, together with any accrued interest thereon, the Available Amount of such Liquidity Facility shall be reinstated by an amount equal to the amount of such Interest Drawing so reimbursed to the applicable Liquidity Provider but not to exceed the Stated Amount for such Liquidity Facility; provided , however , that the Available Amount of such Liquidity Facility shall not be so reinstated in part or in full pursuant to the foregoing provisions of this Section 3.05(g) at any time if (x) both a Performing Note Deficiency exists and a Liquidity Event of Default shall have occurred and be continuing with respect to the relevant Liquidity Facility or (y) a Final Drawing, Downgrade Drawing, Non-Extension Drawing or Special Termination Drawing shall have occurred with respect to such Liquidity Facility or an Interest Drawing shall have been converted into a Final Drawing. Notwithstanding anything to the contrary, in the event that, with respect to any particular Liquidity Facility, (i) funds are withdrawn from the related Cash Collateral Account pursuant to clause (i) or (ii) of Section 3.05(f) or (ii) such Liquidity Facility shall become a Downgraded Facility or a Non-Extended Facility at a time when unreimbursed Interest Drawings under such Liquidity Facility have reduced the Available Amount thereunder to zero, then funds received by the Subordination Agent at any time, other than (x) any time when both a Performing Note Deficiency exists and a Liquidity Event of Default shall have occurred and be continuing with respect to such Liquidity Facility or (y) any time after a Final Drawing shall have occurred with respect to such Liquidity Facility or an Interest Drawing for such Liquidity Facility shall have been converted into a Final Drawing, shall be deposited in such Cash Collateral Account as and to the extent provided in clause “fourth” of Section 3.02 and applied in accordance with Section 3.05(f).

(h) Reimbursement . The amount of each drawing under the Liquidity Facilities shall be due and payable, together with interest thereon, on the dates and at the rates, respectively, provided in the Liquidity Facilities.

(i) Final Drawing . Upon receipt from a Liquidity Provider of a Termination Notice with respect to its applicable Liquidity Facility, the Subordination Agent shall, not later than the date specified in such Termination Notice, in accordance with the terms of such Liquidity Facility, request a drawing under such Liquidity Facility of the Available Amount thereunder (a “ Final Drawing ”). Amounts drawn pursuant to a Final Drawing shall be maintained and invested in accordance with Section 3.05(f).

(j) Adjustments of Stated Amount . Promptly following each date on which the Required Amount of the Liquidity Facility for a relevant Class of Certificates is reduced as a result of a reduction in the Pool Balance with respect to such Certificates or otherwise, the Subordination Agent shall, if any such Liquidity Facility provides for reductions of the Stated Amount of such Liquidity Facility and if such reductions are not automatic, request such Liquidity Provider for such Class of Certificates to reduce such Stated Amount to an amount equal to the Required Amount with respect to such Liquidity Facility (as calculated by the Subordination Agent after giving effect to such payment). Each such request shall be made in accordance with the provisions of the applicable Liquidity Facility.

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	42

Exhibit 4.1

(k) Special Termination Drawing . Upon receipt from a Liquidity Provider of a Special Termination Notice with respect to any Liquidity Facility, the Subordination Agent shall, not later than the date specified in such Special Termination Notice, in accordance with the terms of such Liquidity Facility, request a drawing under such Liquidity Facility of the Available Amount thereunder (a “ Special Termination Drawing ”). Amounts drawn pursuant to a Special Termination Drawing shall be maintained and invested in accordance with Section 3.05(f) hereof.

(l) Relation to Subordination Provisions . Interest Drawings under the Liquidity Facilities and withdrawals from the Cash Collateral Accounts, in each case, in respect of interest on the Certificates of any Class, will be distributed to the Trustee for such Class of Certificates, notwithstanding Sections 2.01(b) and 3.02.

(m) Assignment of Liquidity Facility . The Subordination Agent agrees not to consent to the assignment by any Liquidity Provider of any of its rights or obligations under any Liquidity Facility or any interest therein unless (i) Spirit shall have consented to such assignment and (ii) each Rating Agency shall have provided a Ratings Confirmation with respect to each Class of Certificates then rated by such Rating Agency in connection with such assignment; provided , that the Subordination Agent shall consent to such assignment if the conditions in the foregoing clauses (i) and (ii) are satisfied, and the foregoing is not intended to and shall not be construed to limit the rights of any initial Liquidity Provider under Section 3.05(e)(ii).

Article IV

EXERCISE OF REMEDIES

Section 4.01 Directions from the Controlling Party . (a) (i) Following the occurrence and during the continuation of an Indenture Event of Default under any Indenture, the Controlling Party shall direct the Subordination Agent, as the holder of the Equipment Notes issued under such Indenture, which in turn shall direct the Loan Trustee under such Indenture, in the exercise of remedies available to the holders of such Equipment Notes, including, without limitation, the ability to vote all such Equipment Notes held by the Subordination Agent in favor of Accelerating such Equipment Notes in accordance with the provisions of such Indenture. Subject to Section 4.01(a)(iii), if the Equipment Notes issued pursuant to any Indenture have been Accelerated following an Indenture Event of Default with respect thereto, the Controlling Party may direct the Subordination Agent to sell, assign, contract to sell or otherwise dispose of and deliver all (but not less than all) of such Equipment Notes to any Person at public or private sale, at any location at the option of the Controlling Party, all upon such terms and conditions as the Controlling Party may reasonably deem advisable and in accordance with applicable law.

(ii) Following the occurrence and during the continuation of an Indenture Event of Default under any Indenture, in the exercise of remedies pursuant to such Indenture, the Loan Trustee under such Indenture may be directed to lease the related Aircraft to any Person (including Spirit) so long as the Loan Trustee in doing so acts in a “commercially reasonable” manner within the meaning of Article 9 of the Uniform Commercial Code as in effect in any applicable jurisdiction (including Sections 9-610 and 9-627 thereof).

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Exhibit 4.1

(iii) Notwithstanding the foregoing, so long as any Certificates remain Outstanding, during the period ending on the date which is nine months after the earlier of (x) the Acceleration of the Equipment Notes issued pursuant to any Indenture or (y) the occurrence of a Spirit Bankruptcy Event, without the consent of each Trustee (other than the Trustee of any Trust all of the Certificates of which are held or beneficially owned by Spirit and/or its Affiliates), no Aircraft subject to the Lien of such Indenture or such Equipment Notes may be sold if the net proceeds from such sale would be less than the Minimum Sale Price for such Aircraft or such Equipment Notes.

(iv) Upon the occurrence and continuation of an Indenture Event of Default under any Indenture, the Subordination Agent will obtain three desktop appraisals from the Appraisers selected by the Controlling Party setting forth the current market value, current lease rate and distressed value (in each case, as defined by the International Society of Transport Aircraft Trading or any successor organization) of the Aircraft subject to such Indenture (each such appraisal, an “ Appraisal ” and the current market value appraisals being referred to herein as the “ Post-Default Appraisals ”). For so long as any Indenture Event of Default shall be continuing under any Indenture, and without limiting the right of the Controlling Party to request more frequent Appraisals, the Subordination Agent will obtain updated Appraisals on the date that is 364 days from the date of the most recent Appraisal (or if a Spirit Bankruptcy Event shall have occurred and is continuing, on the date that is 180 days from the date of the most recent Appraisal) and shall (acting on behalf of each Trustee (other than the Class C Trustee)) post such Appraisals on DTC’s Internet bulletin board and make such other commercially reasonable efforts as the Subordination Agent may deem appropriate to make such Appraisals available to all Certificateholders.

(b) Following the occurrence and during the continuance of an Indenture Event of Default under any Indenture, the Controlling Party shall take such actions as it may reasonably deem most effectual to complete the sale or other disposition of the relevant Aircraft or Equipment Notes. In addition, in lieu of any sale, assignment, contract to sell or other disposition, the Controlling Party may maintain or cause the Subordination Agent to maintain possession of such Equipment Notes and continue to apply monies received in respect of such Equipment Notes in accordance with Article III hereof. In addition, in lieu of such sale, assignment, contract to sell or other disposition, or in lieu of such maintenance of possession, the Controlling Party may direct the Subordination Agent to, subject to the terms and conditions of the related Indenture, instruct the Loan Trustee under such Indenture to foreclose on the Lien on the related Aircraft or to take any other remedial action permitted under such Indenture or under any applicable law.

Amended and Restated Intercreditor Agreement (2015-1)
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	44

Exhibit 4.1

adequate protection stipulation, an extension under Section 1110(b) of the Bankruptcy Code or otherwise) to effect any such restructuring proposal with or on behalf of Spirit unless and until the material economic terms and conditions of such restructuring proposal shall have been made available to all Certificateholders and each Liquidity Provider that has not made a Final Drawing for a period of not less than 15 calendar days (except that such requirement shall not apply to any such term sheet, stipulation or other agreement that is to be effective on or as of any date occurring during the 60-Day Period and that is initially effective for a period not exceeding three months from the expiry of the 60-Day Period (an “ Interim Restructuring Arrangement ”)). The foregoing provisions of this Section 4.01(c): (i) shall not apply to any extension of a Restructuring Arrangement with respect to which such provisions have been complied with in connection with the original entry thereof if the possibility of such extension has been disclosed in satisfaction of the notification requirements of such provisions and such extension shall not amend or modify any of the other terms and conditions of such Restructuring Arrangement and (ii) shall apply to the initial extension of an Interim Restructuring Arrangement beyond the three months following the expiry of the 60-Day Period but not to any subsequent extension of such Interim Restructuring Arrangement, if the possibility of such subsequent extension has been disclosed in satisfaction of the notification requirements of such provisions and such subsequent extension shall not amend or modify any of the other terms and conditions of such Interim Restructuring Arrangement. In the event that any Certificateholder gives irrevocable notice of the exercise of its right to purchase all (but not less than all) of the Class of Certificates represented by the then Controlling Party pursuant to the applicable Trust Agreement, prior to the expiry of the 15-day notice period specified above, such Controlling Party may not direct the Subordination Agent or any Trustee to enter into any such restructuring proposal with respect to any of the Aircraft, unless and until such Certificateholder shall fail to purchase such Class of Certificates on the date that it is required to make such purchase.

Section 4.02 Remedies Cumulative . To the extent permitted by applicable law, each and every right, power and remedy given to the Trustees, the Liquidity Providers, the Controlling Party or the Subordination Agent specifically or otherwise in this Agreement shall be cumulative and shall be in addition to every other right, power and remedy herein specifically given or now or hereafter existing at law, in equity or by statute, and each and every right, power and remedy whether specifically herein given or otherwise existing may, subject always to the terms and conditions hereof, be exercised from time to time and as often and in such order as may be deemed expedient by any Trustee, any Liquidity Provider, the Controlling Party or the Subordination Agent, as appropriate, and the exercise or the beginning of the exercise of any right, power or remedy shall not be construed to be a waiver of the right to exercise at the same time or thereafter any other right, power or remedy. No delay or omission by any Trustee, any Liquidity Provider, the Controlling Party or the Subordination Agent in the exercise of any right, remedy or power or in the pursuit of any remedy shall, to the extent permitted by applicable law, impair any such right, power or remedy or be construed to be a waiver of any default or to be an acquiescence therein.

Section 4.03 Discontinuance of Proceedings . In case any party to this Agreement (including the Controlling Party in such capacity) shall have instituted any Proceeding to enforce any right, power or remedy under this Agreement by foreclosure, entry or otherwise, and such Proceeding shall have been discontinued or abandoned for any reason or shall have been determined adversely to the Person instituting such Proceeding, then and in every such case each such party shall, subject to any determination

Amended and Restated Intercreditor Agreement (2015-1)
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	45

Exhibit 4.1

in such Proceeding, be restored to its former position and rights hereunder, and all rights, remedies and powers of such party shall continue as if no such Proceeding had been instituted.

Section 4.04 Right of Certificateholders and the Liquidity Providers to Receive Payments Not to Be Impaired . Anything in this Agreement to the contrary notwithstanding but subject to each Trust Agreement, the right of any Certificateholder or any Liquidity Provider, respectively, to receive payments hereunder (including, without limitation, pursuant to Section 3.02) when due, or to institute suit for the enforcement of any such payment on or after the applicable Distribution Date, shall not be impaired or affected without the consent of such Certificateholder or such Liquidity Provider, respectively.

Article V

DUTIES OF THE SUBORDINATION AGENT; AGREEMENTS OF TRUSTEES, ETC.

Section 5.01 Notice of Indenture Event of Default or Triggering Event . (a) If the Subordination Agent shall have knowledge of an Indenture Event of Default or a Triggering Event, the Subordination Agent shall promptly give notice thereof to the Rating Agencies, Spirit, the Liquidity Providers and the Trustees by telegram, cable, facsimile or telephone (to be promptly confirmed in writing), unless such Indenture Event of Default or Triggering Event shall have been cured or waived. For all purposes of this Agreement, in the absence of actual knowledge, the Subordination Agent shall not be deemed to have knowledge of any Indenture Event of Default or Triggering Event unless notified in writing by Spirit, one or more Trustees, one or more Liquidity Providers or one or more Certificateholders; and “actual knowledge” (as used in the foregoing clause) of the Subordination Agent shall mean actual knowledge of an officer in the Corporate Trust Office of the Subordination Agent.

(b) Other Notices . The Subordination Agent will furnish to each Liquidity Provider and each Trustee, promptly upon receipt thereof, duplicates or copies of all reports, notices, requests, demands, certificates, financial statements and other instruments furnished to the Subordination Agent as registered holder of the Equipment Notes or otherwise in its capacity as Subordination Agent to the extent the same shall not have been otherwise directly distributed to such Liquidity Provider or such Trustee, as applicable, pursuant to any other Operative Agreement.

(c) Securities Position . Upon the occurrence of an Indenture Event of Default, the Subordination Agent shall instruct the Trustees (other than the Class C Trustee) to, and the Trustees (other than the Class C Trustee) shall, request that DTC post on its Internet bulletin board a securities position listing setting forth the names of all the parties reflected on DTC’s books as holding interests in the Certificates (other than the Class C Certificates).

(d) Reports . Promptly after the occurrence of a Triggering Event or an Indenture Event of Default resulting from the failure of Spirit to make payments on any Equipment Note and on every Regular Distribution Date while the Triggering Event or such Indenture Event of Default shall be continuing, the Subordination Agent will provide to the Trustees, the Liquidity Providers, the Rating Agencies and Spirit a statement setting forth the following information:

(i) after a Spirit Bankruptcy Event, with respect to each Aircraft, whether such Aircraft is (A) subject to the 60-Day Period, (B) subject to an election by Spirit under Section 1110(a) of the

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Exhibit 4.1

Bankruptcy Code, (C) covered by an agreement contemplated by Section 1110(b) of the Bankruptcy Code or (D) not subject to any of (A), (B) or (C);

(ii) to the best of the Subordination Agent’s knowledge, after requesting such information from Spirit, (A) whether the Aircraft are currently in service or parked in storage, (B) the maintenance status of the Aircraft and (C) the location of the Engines (as defined in the Indentures);

(iii) the current Pool Balance of each Class of Certificates, the Eligible B Pool Balance, the Eligible C Pool Balance and the outstanding principal amount of all Equipment Notes;

(iv) the expected amount of interest which will have accrued on the Equipment Notes and on the Certificates as of the next Regular Distribution Date;

(v) the amounts paid to each Person on such Distribution Date pursuant to this Agreement;

(vi) details of the amounts paid on such Distribution Date identified by reference to the relevant provision of this Agreement and the source of payment (by Aircraft and party);

(vii) if the Subordination Agent has made a Final Drawing or a Special Termination Drawing under any Liquidity Facility;

(viii) the amounts currently owed to each Liquidity Provider;

(ix) the amounts drawn under each Liquidity Facility; and

(x) after a Spirit Bankruptcy Event, any operational reports filed by Spirit with the bankruptcy court which are available to the Subordination Agent on a non-confidential basis.

Section 5.02 Indemnification . The Subordination Agent shall not be required to take any action or refrain from taking any action under Article IV unless the Subordination Agent shall have received indemnification against any risks that may be incurred in connection therewith in form and substance reasonably satisfactory to it, including, without limitation, adequate advances against costs (including fees and expenses) that may be incurred by it in connection therewith. The Subordination Agent shall not be required to take any action under Article IV, nor shall any other provision of this Agreement or any other Operative Agreement be deemed to impose a duty on the Subordination Agent to take any action, if the Subordination Agent shall have been advised by outside counsel that such action is contrary to the terms hereof or is otherwise contrary to law. Under no circumstances shall the Subordination Agent be required to expend or risk its own funds or otherwise incur any financial liability in performing its duties or exercising its rights or powers hereunder if it shall have reasonable grounds for believing that repayment of such funds is not assured to it.

Amended and Restated Intercreditor Agreement (2015-1)
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	47

Exhibit 4.1

any right of indemnity in respect of any such cost or expense) promptly take such action as may be necessary to discharge duly all Liens on any of the Trust Accounts or any monies deposited therein that are attributable to the Subordination Agent in its individual capacity and that are unrelated to the transaction contemplated hereby and by the other Operative Agreements.

Section 5.04 Notice from the Liquidity Providers and Trustees . If any Liquidity Provider or Trustee has notice of an Indenture Event of Default or a Triggering Event, such Person shall promptly give notice thereof to all other Liquidity Providers and Trustees and to the Subordination Agent; provided , however , that no such Person shall have any liability hereunder as a result of its failure to deliver any such notice.

Article VI

THE SUBORDINATION AGENT

Section 6.01 Authorization; Acceptance of Trusts and Duties . Each Trustee hereby designates and appoints the Subordination Agent as the agent and trustee of such Trustee under the applicable Liquidity Facility (if any) and authorizes the Subordination Agent to enter into the applicable Liquidity Facility as agent and trustee for such Trustee. Each of the Liquidity Providers and the Trustees hereby designates and appoints the Subordination Agent as the Subordination Agent under this Agreement. WTNA accepts the trusts and duties hereby created and applicable to it and agrees to perform such duties, but only upon the terms of this Agreement and agrees to receive, handle and disburse all monies received by it in accordance with the terms hereof. The Subordination Agent shall have no liability hereunder except (a) for its own willful misconduct or negligence, (b) as provided in Section 2.02 and the last sentence of Section 5.03, (c) for liabilities that may result from the inaccuracy of any representation or warranty of the Subordination Agent made in its individual capacity in any Operative Agreement and (d) as otherwise expressly provided herein or in the other Operative Agreements.

Section 6.02 Absence of Duties . The Subordination Agent shall have no duty to see to any recording or filing of this Agreement or any other document, or to see to the maintenance of any such recording or filing.

Amended and Restated Intercreditor Agreement (2015-1)
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	48

Exhibit 4.1

Section 6.03 No Representations or Warranties as to Documents . The Subordination Agent shall not be deemed to have made any representation or warranty as to the validity, legality or enforceability of this Agreement or any other Operative Agreement or as to the correctness of any statement contained herein or therein (other than the representations and warranties of the Subordination Agent made in its individual capacity under any Operative Agreement), except that the Subordination Agent hereby represents and warrants that each of said specified documents to which it is a party has been or will be duly executed and delivered by one of its officers who is and will be duly authorized to execute and deliver such document on its behalf. The Certificateholders, the Trustees and the Liquidity Providers make no representation or warranty hereunder whatsoever.

Section 6.04 No Segregation of Monies; No Interest . Any monies paid to or retained by the Subordination Agent pursuant to any provision hereof and not then required to be distributed to any Trustee or any Liquidity Provider as provided in Articles II and III or deposited into one or more Trust Accounts need not be segregated in any manner except to the extent required by such Articles II and III and by law, and the Subordination Agent shall not (except as otherwise provided in Section 2.02) be liable for any interest thereon; provided , however , that any payments received or applied hereunder by the Subordination Agent shall be accounted for by the Subordination Agent so that any portion thereof paid or applied pursuant hereto shall be identifiable as to the source thereof.

Section 6.05 Reliance; Agents; Advice of Counsel . The Subordination Agent shall not incur any liability to anyone in acting upon any signature, instrument, notice, resolution, request, consent, order, certificate, report, opinion, bond or other document or paper believed by it to be genuine and believed by it to be signed by the proper party or parties. As to the Pool Balance of any Trust as of any date, the Subordination Agent may for all purposes hereof rely on a certificate signed by any Responsible Officer of the applicable Trustee, and such certificate shall constitute full protection to the Subordination Agent for any action taken or omitted to be taken by it in good faith in reliance thereon. As to any fact or matter relating to the Liquidity Providers or the Trustees the manner of ascertainment of which is not specifically described herein, the Subordination Agent may for all purposes hereof rely on a certificate, signed by any Responsible Officer of the applicable Liquidity Provider or Trustee, as the case may be, as to such fact or matter, and such certificate shall constitute full protection to the Subordination Agent for any action taken or omitted to be taken by it in good faith in reliance thereon. In the administration of the trusts hereunder, the Subordination Agent may (a) execute any of the trusts or powers hereof and perform its powers and duties hereunder directly or through agents or attorneys and (b) consult with counsel, accountants and other skilled Persons to be selected and retained by it. The Subordination Agent shall not be liable for anything done, suffered or omitted in good faith by it in accordance with the advice or opinion of any such counsel, accountants or other skilled Persons acting within such counsel’s, accountants’ or Person’s area of competence (so long as the Subordination Agent shall have exercised reasonable care and judgment in selecting such Persons).

Section 6.06 Capacity in Which Acting . The Subordination Agent acts hereunder solely as agent or trustee herein and not in its individual capacity, except as otherwise expressly provided herein and in the Operative Agreements.

Section 6.07 Compensation . The Subordination Agent shall be entitled to such compensation, including reasonable expenses and disbursements, for all services rendered hereunder as Spirit

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Exhibit 4.1

and the Subordination Agent may agree from time to time in writing and shall have a priority claim to the extent set forth in Article III on all monies collected hereunder for the payment of such compensation, to the extent that such compensation shall not be paid by others. The Subordination Agent agrees that it shall have no right against any Trustee or any Liquidity Provider for any fee as compensation for its services as agent under this Agreement. The provisions of this Section 6.07 shall survive the termination of this Agreement.

Section 6.08 May Become Certificateholder . The institution acting as Subordination Agent hereunder may become a Certificateholder and have all rights and benefits of a Certificateholder to the same extent as if it were not the institution acting as the Subordination Agent.

Section 6.09 Subordination Agent Required; Eligibility . There shall at all times be a Subordination Agent hereunder that is a Citizen of the United States, a bank, trust company or other financial institution organized and doing business under the laws of the United States or any state thereof and eligible to act as a trustee under Section 310(a) of the Trust Indenture Act of 1939, as amended, and that has a combined capital and surplus of at least $75,000,000 (or a combined capital and surplus in excess of $5,000,000 and the obligations of which, whether now in existence or hereafter incurred, are fully and unconditionally guaranteed by a corporation organized under the laws of the United States or any State or territory thereof or the District of Columbia and having a combined capital and surplus of at least $75,000,000). If such bank, trust company or other financial institution or such corporation publishes reports of condition at least annually, pursuant to law or to the requirements of federal, state, territorial or District of Columbia supervising or examining authority, then for the purposes of this Section 6.09 the combined capital and surplus of such bank, trust company or other financial institution or such corporation shall be deemed to be its combined capital and surplus as set forth in its most recent report of condition so published.

In case at any time the Subordination Agent shall cease to be eligible in accordance with the provisions of this Section 6.09, the Subordination Agent shall resign immediately in the manner and with the effect specified in Section 7.01.

Section 6.10 Money to Be Held in Trust . All Equipment Notes, monies and other property deposited with or held by the Subordination Agent pursuant to this Agreement shall be held in trust for the benefit of the parties entitled to such Equipment Notes, monies and other property and the Subordination Agent, in its individual capacity, hereby waives all rights of set-off and counterclaim with respect to all such property.

Section 6.11 Notice of Substitution or Replacement of Airframe. If the Subordination Agent, in its capacity as a holder of Equipment Notes issued under an Indenture, receives a notice of substitution of a Substitute Airframe (as defined in such Indenture) pursuant to Section 7.04(e) of such Indenture or a notice of delivery of a Replacement Airframe (as defined in such Indenture) pursuant to Section 7.05(a) of such Indenture, the Subordination Agent shall promptly (i) provide a copy of such notice to each Trustee, each Liquidity Provider and each Rating Agency and (ii) on behalf of each Trustee (other than the Class C Trustee) post such notice on DTC’s Internet bulletin board and make such other commercially reasonable efforts as the Subordination Agent may deem appropriate to make the contents of such notice available to all Certificateholders.

Amended and Restated Intercreditor Agreement (2015-1)
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Exhibit 4.1

Article VII

SUCCESSOR SUBORDINATION AGENT

Section 7.01 Replacement of Subordination Agent; Appointment of Successor . (a) The Subordination Agent or any successor thereto must resign if at any time it fails to comply with Section 6.09 and may resign at any time without cause by giving 60 days’ prior written notice to Spirit, the Trustees and the Liquidity Providers. The Controlling Party or Spirit (only so long as no Indenture Event of Default has occurred or is continuing) may remove the Subordination Agent for cause by so notifying the Subordination Agent and may appoint a successor Subordination Agent. The Controlling Party (or the party that would be the Controlling Party if an Indenture Event of Default had occurred) shall remove the Subordination Agent if:

(1) the Subordination Agent fails to comply with Section 6.09;

(2) the Subordination Agent is adjudged bankrupt or insolvent or files a bankruptcy petition;

(3) a receiver of the Subordination Agent shall be appointed or any public officer shall take charge or control of the Subordination Agent or its property or affairs for the purpose of rehabilitation, conservation or liquidation; or

(4) the Subordination Agent otherwise becomes incapable of acting.

If the Subordination Agent resigns or is removed or if a vacancy exists in the office of Subordination Agent for any reason (the Subordination Agent in such event being referred to herein as the retiring Subordination Agent), the Controlling Party (or the party that would be the Controlling Party if an Indenture Event of Default had occurred) shall promptly appoint a successor Subordination Agent. If a successor Subordination Agent shall not have been appointed within 60 days after such notice of resignation or removal, the retiring Subordination Agent, one or more of the Trustees or one or more of the Liquidity Providers may petition any court of competent jurisdiction for the appointment of a successor Subordination Agent to act until such time, if any, as a successor shall have been appointed as provided above.

A successor Subordination Agent shall deliver (x) a written acceptance of its appointment as Subordination Agent hereunder to the retiring Subordination Agent and (y) a written assumption of its obligations hereunder and under each Liquidity Facility to each party hereto, upon which the resignation or removal of the retiring Subordination Agent shall become effective, and the successor Subordination Agent shall have all the rights, powers and duties of the Subordination Agent under this Agreement. The successor Subordination Agent shall mail a notice of its succession to Spirit, the Liquidity Providers and the Trustees. The retiring Subordination Agent shall promptly transfer its rights under each of the Liquidity Facilities and all of the property and all books and records, or true, complete and correct copies thereof, held by it as Subordination Agent to the successor Subordination Agent.

If the Subordination Agent fails to comply with Section 6.09 (to the extent applicable), one or more of the Trustees or one or more of the Liquidity Providers may petition a court of competent jurisdiction for the removal of the Subordination Agent and the appointment of a successor Subordination Agent.

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Exhibit 4.1

Notwithstanding the foregoing, no resignation or removal of the Subordination Agent shall be effective unless and until a successor has been appointed. No appointment of a successor Subordination Agent shall be effective unless and until the Rating Agencies shall have delivered a Ratings Confirmation with respect to each Class of Certificates then rated by the Rating Agencies.

(b) Any corporation, bank, trust company or other financial institution into which the Subordination Agent may be merged or converted or with which it may be consolidated, or any corporation, bank, trust company or other financial institution resulting from any merger, conversion or consolidation to which the Subordination Agent shall be a party, or any corporation, bank, trust company or other financial institution succeeding to all or substantially all of the corporate trust business of the Subordination Agent, shall be the successor of the Subordination Agent hereunder, provided that such corporation, bank, trust company or other financial institution shall be otherwise qualified and eligible under Section 6.09, without the execution or filing of any paper or any further act on the part of any of the parties hereto, except that such corporation, bank, trust company or other financial institution shall give prompt notice of such transaction to the Liquidity Providers and Spirit.

Article VIII

SUPPLEMENTS AND AMENDMENTS

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Exhibit 4.1

without the additional written consent of Spirit. Notwithstanding the foregoing, without the consent of each Certificateholder affected thereby and each Liquidity Provider, no supplement, amendment or modification of this Agreement may (i) reduce the percentage of the interest in any Trust evidenced by the Certificates issued by such Trust necessary to consent to modify or amend any provision of this Agreement or to waive compliance therewith or (ii) except as provided in the last sentence of this Section 8.01(a) or Section 8.01(c) or Section 8.01(d), modify Section 2.04, 3.02 or 3.03 hereof relating to the distribution of monies received by the Subordination Agent hereunder from the Equipment Notes or pursuant to the Liquidity Facilities. Nothing contained in this Section 8.01(a) shall require the consent of a Trustee at any time following the payment of Final Distributions with respect to the related Class of Certificates. If the Replacement Liquidity Facility for any Liquidity Facility is to be comprised of more than one instrument as contemplated by the definition of the term “Replacement Liquidity Facility”, then each party hereto agrees to amend this Agreement and the other Operative Agreements to incorporate appropriate mechanics for multiple Liquidity Facilities for a single Trust.

(b) In the event that the Subordination Agent, as the registered holder of any Equipment Notes, receives a request for the giving of notice or its consent to any amendment, supplement, modification, approval, consent or waiver under such Equipment Notes, the Indenture pursuant to which such Equipment Notes were issued, the related Participation Agreement or other related document, (i) if no Indenture Event of Default shall have occurred and be continuing with respect to such Indenture, the Subordination Agent shall request directions with respect to each series of such Equipment Notes from the Trustee of the Trust which holds such Equipment Notes and shall vote or consent in accordance with the directions of such Trustee and (ii) if any Indenture Event of Default shall have occurred and be continuing with respect to such Indenture, the Subordination Agent will exercise its voting rights as directed by the Controlling Party, subject to Sections 4.01 and 4.04. Notwithstanding the foregoing, without the consent of each Liquidity Provider and each affected Certificateholder holding Certificates representing a Fractional Undivided Interest in the Equipment Notes under the applicable Indenture held by the Subordination Agent, no such amendment, supplement, modification, approval, consent or waiver shall (i) reduce the principal amount of, Premium, if any, or interest on, any such Equipment Note under such Indenture; (ii) change the date on which any principal amount of, Premium, if any, or interest on any such Equipment Note under such Indenture, is due or payable; (iii) create any Lien with respect to the Collateral subject to such Indenture prior to or pari passu with the Lien thereon under such Indenture except such as are permitted by such Indenture; provided that, without the consent of each Certificateholder, no such amendment, supplement, modification, approval, consent or waiver shall modify Section 3.03 or Section 9.02(a)(3) of such Indenture or deprive any Certificateholder of the benefit of the Lien of such Indenture on such Collateral, except as provided in connection with the exercise of remedies under Article IV of such Indenture or as otherwise permitted by such Indenture; (iv) reduce the percentage of the outstanding principal amount of the Equipment Notes under such Indenture the consent of whose holders is required for any supplemental agreement, or the consent of whose holders is required for any waiver of compliance with certain provisions of such Indenture or of certain defaults thereunder or their consequences provided for in such Indenture; or (v) make any change in Section 4.05 or Section 9.02 of such Indenture, except to provide that certain other provisions of such Indenture cannot be modified or waived without the consent of each holder of an Equipment Note under such Indenture affected thereby.

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Exhibit 4.1

(c) If ( x ) the Series B Equipment Notes or Series C Equipment Notes (or any series of Additional Equipment Notes), with respect to all of the Aircraft for which Series B Equipment Notes or Series C Equipment Notes (or such series of Additional Equipment Notes) are at the time outstanding, are redeemed and new Equipment Notes of corresponding series are to be issued with respect to any or all of the Aircraft under the applicable Indentures or ( y ) at any time following the payment in full of the Series B Equipment Notes or Series C Equipment Notes (or any series of Additional Equipment Notes) with respect to all of the Aircraft for which Series B Equipment Notes or Series C Equipment Notes (or such series of Additional Equipment Notes) are at the time outstanding and new Equipment Notes of corresponding series are to be issued with respect to any or all of the Aircraft under the applicable Indentures, in each case in accordance with the terms of Section 2.02 of each such Indenture and Section 4(a)(v) of the Note Purchase Agreement, such series of new Equipment Notes in each case (the “ Refinancing Equipment Notes ”) shall be issued to a new pass through trust (a “ Refinancing Trust ”) that issues a class of pass through certificates (the “ Refinancing Certificates ”) to certificateholders (each, a “ Refinancing Certificateholder ”) pursuant to a pass through trust agreement (a “ Refinancing Trust Agreement ”) with a trustee (a “ Refinancing Trustee ”). A Refinancing Trust, a Refinancing Trustee and the Refinancing Certificates shall be subject to all of the provisions of this Agreement in the same manner as the Trust, the Trustee and the Certificates of the Class corresponding to the series of the refinanced Equipment Notes, including, the subordination of the Refinancing Certificates to the extent provided herein to ( A ) in the case of any Refinancing Certificates issued in respect of Class B Certificates, the Administration Expenses, the Liquidity Obligations and the Class A Certificates and (B) in the case of any Refinancing Certificates issued in respect of Class C Certificates, the Administration Expenses, the Liquidity Obligations, the Class A Certificates and the Class B Certificates and (C) in the case of any Refinancing Certificates issued in respect of any Additional Certificates, the Administration Expenses, the Liquidity Obligations, the Class A Certificates, the Class B Certificates, the Class C Certificates and, if applicable, any other class of Additional Certificates that rank senior, in priority of payment of “Expected Distributions” under this Agreement, to such Refinancing Certificates. Such issuance of Refinancing Equipment Notes and Refinancing Certificates and the amendment of this Agreement as provided below shall require Ratings Confirmation with respect to each Class of Certificates then rated by the Rating Agencies and shall not materially adversely affect any of the Trustees in their individual capacities or any of the Liquidity Providers. This Agreement shall be amended by written agreement of Spirit and the Subordination Agent to give effect to the issuance of any Refinancing Certificates subject to the following terms and conditions:

(i) the Refinancing Trustee shall be added as a party to this Agreement;

(ii) the definitions of “Certificate”, “Class”, “Class B Certificates”, “Class C Certificates”, “Final Legal Distribution Date”, “Trust”, “Trust Agreement” and “Controlling Party” (and such other applicable definitions) shall be revised, as appropriate, to reflect such issuance (and the subordination, as applicable, of the Refinancing Certificates and the Refinancing Equipment Notes);

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	54

Exhibit 4.1

in respect of the Liquidity Facilities, (B) in the case of any Refinancing Certificates issued in respect of any Class C Certificates, shall be subordinated to the Administration Expenses, the Liquidity Obligations, the Class A Certificates and the Class B Certificates and (C) in the case of any Refinancing Certificates issued in respect of any Additional Certificates, shall be subordinated, at least, to the Administration Expenses, the Liquidity Obligations, the Class A Certificates, the Class B Certificates and the Class C Certificates; provided that, (x) in each case, Ratings Confirmation with respect to each Class of Certificates then rated by the Rating Agencies shall have been obtained and (y) in the case of clause (A) the prior written consent of the Class A Liquidity Provider shall have been obtained;

(iv) the Refinancing Certificates cannot be issued to Spirit but may be issued to any of Spirit’s Affiliates so long as such Affiliate shall have bankruptcy remote and special purpose provisions in its certificate of incorporation or other organizational documents and any subsequent transfer of such Refinancing Certificates from such Affiliate to any other Affiliate of Spirit shall be similarly restricted; and

(v) the scheduled payment dates on the Refinancing Equipment Notes shall be the Regular Distribution Dates.

The issuance of the Refinancing Certificates in compliance with all of the foregoing terms in clauses (i) to (v) of this Section 8.01(c) shall be deemed to not materially adversely affect any of the Trustee’s rights and obligations and shall not require the consent of any of the Trustees or the holders of any Class of Certificates. Each of the Liquidity Providers hereby agrees and confirms that it shall be deemed to consent to any issuance and amendment in accordance with this Section 8.01(c) (subject to the Class A Liquidity Provider’s consent right in clause (y) to the proviso to Section 8.01(c)(iii)) and that any such issuance and amendment shall not affect any of its respective obligations under the applicable Liquidity Facility, provided that a condition to the issuance of any Refinancing Certificates issued in respect of a Class of Certificates with a Liquidity Facility shall be the payment in full of all amounts owed to the Liquidity Provider under such Liquidity Facility and the termination of such Liquidity Facility upon the issuance of such Refinancing Certificates. The Subordination Agent shall deliver to each Trustee and each Liquidity Provider (other than the Liquidity Provider of such terminated Liquidity Facility) a copy of the amendments made to this Agreement and all opinions, certificates and other documents delivered in connection with the issuance of any Refinancing Certificates.

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	55

Exhibit 4.1

2.04, 3.01 and 3.02 hereof, shall be amended by written agreement of Spirit and the Subordination Agent to provide for the subordination of such class of Additional Certificates to, and to provide for distributions on the Additional Certificates after payment of, the Administration Expenses, the Liquidity Obligations, the Class A Certificates, the Class B Certificates, the Class C Certificates and, if applicable, any other Additional Certificates that rank senior, in priority of payment of “Expected Distributions” under this Agreement, to such Additional Certificates (subject to clause (iii) below). Such issuance, and the amendment of this Agreement as provided below shall require Ratings Confirmation with respect to each Class of Certificates then rated by the Rating Agencies and shall not materially adversely affect any of the Trustees in their individual capacities or any of the Liquidity Providers. This Agreement shall be amended by written agreement of Spirit and the Subordination Agent to give effect to the issuance of any Additional Certificates subject to the following terms and conditions:

(i) the Additional Trustee shall be added as a party to this Agreement;

(ii) the definitions of “Certificate”, “Class”, “Equipment Notes”, “Final Legal Distribution Date”, “Trust”, “Trust Agreement”, and “Controlling Party” (and such other applicable definitions) shall be revised, as appropriate, to reflect the issuance of the Additional Certificates (and the subordination thereof);

(iii) Section 3.02 may be revised, with respect to any class of Additional Certificates, to provide for the distribution of “Adjusted Interest” for such class of Additional Certificates (calculated in a manner substantially similar to the calculation of Class C Adjusted Interest) after the Class C Adjusted Interest (and, if applicable, after any “Adjusted Interest” for any Additional Certificates that rank senior, in priority of payment of “Expected Distributions” under this Agreement, to such Additional Certificates) but before Expected Distributions on the Class A Certificates;

(iv) the Additional Certificates may have the benefit of credit support similar to the Liquidity Facilities or different therefrom, provided that (A) claims for fees, interest, expenses, reimbursement of advances and other obligations arising from such credit support shall be subordinated, at least, to the Administration Expenses, the Liquidity Obligations, the Class A Certificates, the Class B Certificates and the Class C Certificates and (B) Ratings Confirmation with respect to each Class of Certificates then rated by the Rating Agencies shall have been obtained;

(v) the Additional Certificates may be rated by the Rating Agencies;

(vi) the Additional Certificates cannot be issued to Spirit but may be issued to any of Spirit’s Affiliates so long as such Affiliate shall have bankruptcy remote and special purpose provisions in its certificate of incorporation or other organizational documents and any subsequent transfer of such Additional Certificates from such Affiliate to any other Affiliate of Spirit shall be similarly restricted;

(vii) the scheduled payment dates on such series of Additional Equipment Notes shall fall on a Regular Distribution Date; and

(viii) for the avoidance of doubt and without limitation of the foregoing, in the event that any Additional Certificates are issued prior to the Delivery Period Termination Date, the definitions

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	56

Exhibit 4.1

of Deposit Agreement, Escrow and Paying Agent Agreement, Escrow Agent, Escrow Receipts, Paying Agent, Paying Agent Account, Expected Distributions, Final Distributions and Pool Balance (and any other applicable definition) and the related provisions hereof may be appropriately revised to reflect any applicable deposit and escrow arrangement in relation to such Additional Certificates.

The issuance of the Additional Certificates in compliance with all of the foregoing terms in clauses (i) to (viii) of this Section 8.01(d) shall be deemed to not materially adversely affect any of the Trustee’s rights and obligations and shall not require the consent of any of the Trustees or the holders of any Class of Certificates. Each of the Liquidity Providers hereby agrees and confirms that it shall be deemed to consent to any issuance and amendment in accordance with this Section 8.01(d) and that any such issuance and amendment shall not affect any of its respective obligations under the applicable Liquidity Facility. The Subordination Agent shall deliver to each Trustee and each Liquidity Provider a copy of the amendments made to this Agreement and all opinions, certificates and other documents delivered in connection with the issuance of any Additional Certificates.

Section 8.02 Subordination Agent Protected . If, in the reasonable opinion of the institution acting as the Subordination Agent hereunder, any document required to be executed by it pursuant to the terms of Section 8.01 adversely affects any right, duty, immunity or indemnity with respect to such institution under this Agreement or any Liquidity Facility, the Subordination Agent may in its discretion decline to execute such document.

Section 8.03 Effect of Supplemental Agreements . Upon the execution of any amendment, consent or supplement hereto pursuant to the provisions hereof, this Agreement shall be and shall be deemed to be modified and amended in accordance therewith and the respective rights, limitations of rights, obligations, duties and immunities under this Agreement of the parties hereto and beneficiaries hereof shall thereafter be determined, exercised and enforced hereunder subject in all respects to such modifications and amendments, and all the terms and conditions of any such supplemental agreement shall be and be deemed to be part of the terms and conditions of this Agreement for any and all purposes. In executing or accepting any supplemental agreement permitted by this Article VIII, the Subordination Agent shall be entitled to receive, and shall be fully protected in relying upon, an opinion of counsel stating that the execution of such supplemental agreement is authorized or permitted by this Agreement.

Section 8.04 Notice to Rating Agencies . Promptly following its receipt of each amendment, consent, modification, supplement or waiver contemplated by this Article VIII, the Subordination Agent shall send a copy thereof to each Rating Agency.

Article IX

MISCELLANEOUS

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	57

Exhibit 4.1

terminated, this Agreement shall and the trusts created hereby terminate and this Agreement shall be of no further force or effect. Except as aforesaid or otherwise provided, this Agreement and the trusts created hereby shall continue in full force and effect in accordance with the terms hereof.

Section 9.02 Intercreditor Agreement for Benefit of Trustees, Liquidity Providers and Subordination Agent . Subject to the second sentence of Section 9.06 and the provisions of Section 4.04 and 8.01, nothing in this Agreement, whether express or implied, shall be construed to give to any Person other than the Trustees, the Liquidity Providers and the Subordination Agent any legal or equitable right, remedy or claim under or in respect of this Agreement.

Section 9.03 Notices . Unless otherwise expressly specified or permitted by the terms hereof, all notices required or permitted under the terms and provisions of this Agreement shall be in English and in writing, and any such notice may be given by United States mail, courier service or facsimile or any other customary means of communication, and any such notice shall be effective when delivered (or, if mailed, three Business Days after deposit, postage prepaid, in the first class United States mail and, if delivered by facsimile, upon completion of transmission and confirmation by the sender (by a telephone call to a representative of the recipient or by machine confirmation) that such transmission was received),

if to the Subordination Agent, to:

Wilmington Trust, National Association
1100 North Market Street
Wilmington, DE 19890-1605

Attention: Corporate Trust Administration

Ref.: Spirit 2015-1 EETC

Telephone: (302) 636-6294

Telecopy: (302) 636-4140

if to any Trustee, to:

Wilmington Trust, National Association
1100 North Market Street
Wilmington, DE 19890-1605

Attention: Corporate Trust Administration

Ref.: Spirit 2015-1 EETC

Telephone: (302) 636-6294

Telecopy: (302) 636-4140

if to the Liquidity Provider, to:

Natixis, acting via its New York Branch
1251 Avenue of the Americas

New York, NY 10020-1128

Attention: Vinh Nguyen

Telephone: (212) 891-5811
Telecopy: (646) 282-2321

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	58

Exhibit 4.1

Email: vinh.nguyen@us.natixis.com

and

Natixis, acting via its New York Branch
1251 Avenue of the Americas

New York, NY 10020-1128

Attention: Martha Sealy

Telephone: (212) 872-5031
Telecopy: (347) 402-3031

Email: martha.sealy@us.natixis.com

CC: aviationfinanceportfolio@us.natixis.com

Any party, by notice to the other parties hereto, may designate additional or different addresses for subsequent notices or communications. Whenever the words “notice” or “notify” or similar words are used herein, they mean the provision of formal notice as set forth in this Section 9.03.

Section 9.04 Severability . To the extent permitted by applicable law, any provision of this Agreement which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.

Section 9.05 No Oral Modifications or Continuing Waivers . No terms or provisions of this Agreement may be changed, waived, discharged or terminated orally, but only by an instrument in writing signed by the party or other Person against whom enforcement of the change, waiver, discharge or termination is sought and any other party or other Person whose consent is required pursuant to this Agreement and any waiver of the terms hereof shall be effective only in the specific instance and for the specific purpose given.

Section 9.06 Successors and Assigns . All covenants and agreements contained herein shall bind and inure to the benefit of, and be enforceable by, each of the parties hereto and the successors and permitted assigns of each, all as herein provided. In addition, the Spirit Provisions shall inure to the benefit of Spirit and its successors and permitted assigns, and (without limitation of the foregoing) Spirit is hereby constituted, and agreed to be, an express third party beneficiary of the Spirit Provisions.

Section 9.07 Headings . The headings of the various Articles and Sections herein and in the Table of Contents hereto are for convenience of reference only and shall not define or limit any of the terms or provisions hereof.

Section 9.08 Counterparts . This Agreement may be executed in any number of counterparts (and each party shall not be required to execute the same counterpart). Each counterpart of this Agreement including a signature page or pages executed by each of the parties hereto shall be an original counterpart of this Agreement, but all of such counterparts together constitute one instrument.

Section 9.09 Subordination . (a) As between the Liquidity Providers (and any additional liquidity providers in respect of any class of Refinancing Certificates or any Additional Certificates), on the

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	59

Exhibit 4.1

one hand, and the Trustees (and any Refinancing Trustees or any Additional Trustees) and the Certificateholders (and any Refinancing Certificateholders or any Additional Certificateholders), on the other hand, and as among the Trustees (and any Refinancing Trustees or any Additional Trustee) and the related Certificateholders (and any Refinancing Certificateholders or any Additional Certificateholders) this Agreement shall be a subordination agreement for purposes of Section 510 of the Bankruptcy Code.

(b) Notwithstanding the provisions of this Agreement, if prior to the payment in full to the Liquidity Providers of all Liquidity Obligations then due and payable any party hereto shall have received any payment or distribution in respect of Equipment Notes or any other amount under the Indentures or other Operative Agreements which, had the subordination provisions of this Agreement been properly applied to such payment, distribution or other amount, would not have been distributed to such Person, then such payment, distribution or other amount shall be received and held in trust by such Person and paid over or delivered to the Subordination Agent for application as provided herein.

(c) If any Trustee, any Liquidity Provider or the Subordination Agent receives any payment in respect of any obligations owing or amounts distributable hereunder (or, in the case of the Liquidity Providers, in respect of the Liquidity Obligations), which is subsequently invalidated, declared preferential, set aside and/or required to be repaid to a trustee, receiver or other party, then, to the extent of such payment, such obligations or amounts (or, in the case of the Liquidity Providers, such Liquidity Obligations) intended to be satisfied shall be revived and continue in full force and effect as if such payment had not been received.

(d) The Trustees (on behalf of themselves and the holders of Certificates), the Liquidity Providers and the Subordination Agent expressly confirm and agree that the payment priorities and subordination specified in Articles II and III shall apply in all circumstances, notwithstanding (x) the fact that the obligations owed to the Trustees are secured by certain assets and the Liquidity Obligations may not be so secured or (y) the occurrence of a Spirit Bankruptcy Event or any similar event or occurrence relating to any other Person (it being expressly agreed that the payment priorities and subordination specified in Articles II and III shall apply whether or not a claim for post-petition or post-filing interest is allowed in the proceedings resulting from such Spirit Bankruptcy Event or other event or occurrence). The Trustees expressly agree (on behalf of themselves and the holders of Certificates) not to assert priority over the holders of Liquidity Obligations (except as specifically set forth in Section 3.02) due to their status as secured creditors in any bankruptcy, insolvency or other legal proceeding.

(e) Each of the Trustees (on behalf of themselves and the holders of Certificates), the Liquidity Providers and the Subordination Agent may take any of the following actions without impairing its rights under this Agreement:

(i) obtain a Lien on any property to secure any amounts owing to it hereunder, including, in the case of the Liquidity Providers, the Liquidity Obligations;

(ii) obtain the primary or secondary obligation of any other obligor with respect to any amounts owing to it hereunder, including, in the case of the Liquidity Providers, any of the Liquidity Obligations;

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	60

Exhibit 4.1

(iii) renew, extend, increase, alter or exchange any amounts owing to it hereunder, including, in the case of the Liquidity Providers, any of the Liquidity Obligations, or release or compromise any obligation of any obligor with respect thereto;

(iv) refrain from exercising any right or remedy, or delay in exercising any right or remedy, which it may have; or

(v) take any other action which might discharge a subordinated party or a surety under applicable law;

provided , however , that the taking of any such actions by any of the Trustees, the Liquidity Providers or the Subordination Agent shall not prejudice the rights or adversely affect the obligations of any other party under this Agreement.

Section 9.10 Governing Law . THIS AGREEMENT HAS BEEN DELIVERED IN THE STATE OF NEW YORK AND SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

Section 9.11 Submission to Jurisdiction; Waiver of Jury Trial; Waiver of Immunity . (a) Each of the parties hereto, to the extent it may do so under applicable law, for purposes hereof and of all other Operative Agreements hereby (i) irrevocably submits itself to the non-exclusive jurisdiction of the courts of the State of New York sitting in the City of New York and to the non-exclusive jurisdiction of the United States District Court for the Southern District of New York, for the purposes of any suit, action or other proceeding arising out of this Agreement, the subject matter hereof or any of the transactions contemplated hereby brought by any party or parties hereto or thereto, or their successors or permitted assigns and (ii) waives, and agrees not to assert, by way of motion, as a defense, or otherwise, in any such suit, action or proceeding, that the suit, action or proceeding is brought in an inconvenient forum, that the venue of the suit, action or proceeding is improper or that this Agreement or the subject matter hereof or any of the transactions contemplated hereby may not be enforced in or by such courts.

(b) EACH OF THE PARTIES HERETO HEREBY AGREES TO WAIVE ITS RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT AND THE RELATIONSHIP THAT IS BEING ESTABLISHED, including, without limitation, contract claims, tort claims, breach of duty claims and all other common law and statutory claims. Each of the parties warrants and represents that it has reviewed this waiver with its legal counsel, and that it knowingly and voluntarily waives its jury trial rights following consultation with such legal counsel. TO THE EXTENT PERMITTED BY APPLICABLE LAW, THIS WAIVER IS IRREVOCABLE AND CANNOT BE MODIFIED EITHER ORALLY OR IN WRITING, AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT.

(c) To the extent that any Liquidity Provider or any of its properties has or may hereafter acquire any right of immunity, whether characterized as sovereign immunity or otherwise, and whether under

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Exhibit 4.1

the United States Foreign Sovereign Immunities Act of 1976 (or any successor legislation) or otherwise, from any legal proceedings, whether in the United States or elsewhere, to enforce or collect upon this Agreement, including, without limitation, immunity from suit or service of process, immunity from jurisdiction or judgment of any court or tribunal or execution of a judgment, or immunity of any of its property from attachment prior to any entry of judgment, or from attachment in aid of execution upon a judgment, each of the Class A Liquidity Provider and the Class B Liquidity Provider, hereby irrevocably and expressly waives any such immunity, and agrees not to assert any such right or claim in any such proceeding, whether in the United States or elsewhere.

Section 9.12 Non-Petition . Each Liquidity Provider covenants that until one year and one day after the Equipment Notes have been paid in full, it shall not acquiesce, petition or otherwise invoke or cause or join in invoking or causing any Trust or any other Person to invoke the process of any governmental authority for the purpose of commencing or sustaining a case (whether voluntary or not) against such Trust under any bankruptcy, insolvency or similar law or appointing a receiver, liquidator, assignee, trustee, custodian, sequestrator or other similar official of such Trust or any substantial part of its property or ordering the winding up or liquidation of the affairs of such Trust.

Section 9.13 Acknowledgement; Direction; Amendment and Restatement . Each party hereto (including WTNA) (a) agrees that this Agreement is entered into pursuant to and consistent with Section 8.01 of the Original Intercreditor Agreement, (b) acknowledges and agrees that, from and after the date hereof, this Agreement shall constitute the “Intercreditor Agreement” and the Note Purchase Agreement shall constitute the “Note Purchase Agreement,” in each case for all purposes of the Operative Agreements, (c) acknowledges and agrees that, from and after the date hereof, the Series C Equipment Notes, the Class C Certificates, the Class C Certificateholders, the Class C Trust, the Class C Trust Agreement and the Class C Trustee shall constitute “Additional Equipment Notes” (or “Additional Series Equipment Notes”), “Additional Certificates” (or “Additional Series Pass Through Certificates”), “Additional Certificateholders”, an “Additional Trust” (or an “Additional Series Pass Through Trust”), an “Additional Trust Agreement” (or an “Additional Series Pass Through Trust Agreement”) and an “Additional Trustee” (or an “Additional Series Pass Through Trustee”), respectively, in each case for all purposes of the Operative Agreements (as defined in the Original Note Purchase Agreement) and (d) shall have and shall perform all of the rights and obligations relating to it under the Operative Agreements. Each Trustee and Liquidity Provider hereby authorizes, empowers and instructs the Subordination Agent to enter into, execute, deliver and perform its obligations under this Agreement, the Note Purchase Agreement, the First Amendment to Participation Agreement with respect to each Aircraft, the First Amendment to Indenture with respect to each Aircraft and each other document, instrument or writing as may be contemplated by, or necessary or convenient in connection with, any of the foregoing; and further, each Trustee authorizes, empowers and instructs the Subordination Agent, as record holder of the Equipment Notes, to instruct the Loan Trustee as set forth in the First Amendment to Participation Agreement with respect to each Aircraft.

[ Remainder of Page Intentionally Left Blank ]

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Exhibit 4.1

IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be duly executed by their respective officers thereunto duly authorized, as of the date first above written.

WILMINGTON TRUST, NATIONAL ASSOCIATION,

as Trustee for the Class A Trust, Class B Trust and Class C Trust

By: /s/ Jacequline Solone

Name: Jacequline Solone

Title: Vice President

Signature Page

Amended and Restated Intercreditor Agreement (2015-1)
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AMERICAS 94409277

Exhibit 4.1

NATIXIS, ACTING VIA ITS NEW YORK BRANCH,

as Class A Liquidity Provider and Class B Liquidity Provider

By: /s/ Vinh Nguyen

Name: Vinh Nguyen

Title: Director

By: /s/ Lily Cheung

Name: Lily Cheung

Title: Executive Director

Signature Page

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



AMERICAS 94409277

Exhibit 4.1

WILMINGTON TRUST, NATIONAL ASSOCIATION ,
as Subordination Agent

By: /s/ Jacequline Solone

Name: Jacequline Solone

Title: Vice President

Signature Page

Amended and Restated Intercreditor Agreement (2015-1)
(Spirit 2015-1 EETC)



AMERICAS 94409277

Exhibit 4.2

EXECUTION VERSION

TRUST SUPPLEMENT NO. 2015-1C

Dated as of May 10, 2018

between

SPIRIT AIRLINES, INC.

and

WILMINGTON TRUST, NATIONAL ASSOCIATION,

as Trustee,

PASS THROUGH TRUST AGREEMENT

Dated as of August 11, 2015

Spirit Airlines Pass Through Trust 2015-1C

Spirit Airlines Pass Through Certificates,

Series 2015-1C



AMERICAS 94473135 v9		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Table of Contents



		PAGE
Article I DEFINITIONS		2
Section 1.01	Definitions	2
Article II DECLARATION OF TRUST		7
Section 2.01	Declaration of Trust	7
Section 2.02	Permitted Activities	7
Article III THE CERTIFICATES		7
Section 3.01	The Certificates	7
Section 3.02	Terms and Conditions	7
Article IV ISSUANCE AND TRANSFER OF THE CLASS C CERTIFICATES		9
Section 4.01	Issuance of Class C Certificates	9
Section 4.02	Legends	9
Section 4.03	Transfer and Exchange	11
Section 4.04	Amendment of Section 3.04 and Inapplicability of Section 3.05 for the Basic Agreement	12
Article V DISTRIBUTION; STATEMENTS TO CERTIFICATEHOLDERS		12
Section 5.01	Statements to Certificateholders	12
Article VI DEFAULT		13
Section 6.01	Purchase Rights of Certificateholders	13
Article VII THE TRUSTEE		15
Section 7.01	Delivery of Documents; Delivery Dates	15
Section 7.02	[Intentionally omitted]	16
Section 7.03	The Trustee	16
Section 7.04	Representations and Warranties of the Trustee	17
Section 7.05	Trustee Liens	17
Article VIII ADDITIONAL AMENDMENT; SUPPLEMENTAL AGREEMENTS		18
Section 8.01	Amendment of Sections 5.02, 6.07, 7.09, 8.04, 9.01, 12.01 and 12.02 of the Basic Agreement	18
Section 8.02	Supplemental Agreements Without Consent of Class C Certificateholders	18
Section 8.03	Supplemental Agreements with Consent of Class C Certificateholders	19
Section 8.04	Consent of Trustees for Amendment of Section 6.01	19
Article IX MISCELLANEOUS PROVISIONS		19



	i	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2



Section 9.01	Final Termination Date	19
Section 9.02	Basic Agreement Ratified	19
Section 9.03	Governing Law	19
Section 9.04	Counterparts	20
Section 9.05	Intention of Parties	20
Section 9.06	Submission to Jurisdiction.	20
Section 9.07	Successor and Assigns	20
Section 9.08	Normal Commercial Relations	20
Section 9.09	No Recourse against Others	20

EXHIBITS


Exhibit A	- Form of Certificate


Exhibit B	- Amendments to Basic Agreement

SCHEDULES


Schedule I	- Series C Equipment Notes, Principal Amounts, Maturities and Aircraft


Schedule II	- Note Documents



	ii	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

TRUST SUPPLEMENT NO. 2015-1C

This TRUST SUPPLEMENT NO. 2015-1C, dated as of May 10, 2018 (as amended from time to time, the “Trust Supplement”), between SPIRIT AIRLINES, INC., a Delaware corporation (together with any successor in interest pursuant to Section 5.02 of the Basic Agreement, the “Company” or “Spirit”), and WILMINGTON TRUST, NATIONAL ASSOCIATION, a national banking association, as trustee (together with any successor in interest and any successor or other trustee appointed as provided in the Basic Agreement, the “Trustee”) under the Pass Through Trust Agreement, dated as of August 11, 2015, between the Company and Wilmington Trust, National Association (the “Basic Agreement”).

W I T N E S S E T H:

WHEREAS, the Basic Agreement, which is unlimited as to the aggregate face amount of Certificates that may be issued and authenticated thereunder, has heretofore been executed and delivered;

WHEREAS, Spirit owns, and has financed, the 15 aircraft described in Schedule I (each, an “Aircraft” and, collectively, the “Aircraft”);

WHEREAS, Spirit has issued the Class A Certificates and Class B Certificates on August 11, 2015 in order to finance the Aircraft pursuant to the NPA;

WHEREAS, Spirit has issued a Series A Equipment Note and a Series B Equipment Note related to each Aircraft and Spirit wishes to issue a Series C Equipment Note pursuant to the Indenture related to each such Aircraft (as amended by the Indenture Amendment relating to such Indenture);

WHEREAS, the Trustee shall hereby declare the creation of the Class C Trust (as defined below) for the benefit of Holders of the Class C Certificates (as defined below) to be issued in respect of such Class C Trust, and the initial Holders of the Class C Certificates, as grantors of such Class C Trust, by their respective acceptances of the Class C Certificates, shall join in the creation of the Class C Trust with the Trustee;

WHEREAS, all Certificates to be issued by the Class C Trust will evidence Fractional Undivided Interests in the Class C Trust and will have no rights, benefits or interests in respect of any other separate Trust or the property held therein;

WHEREAS, pursuant to the terms and conditions of the Basic Agreement, as supplemented by this Trust Supplement, and the PA Amendments, the Trustee on behalf of the Class C Trust shall on the date hereof purchase the Series C Equipment Notes relating to the Aircraft issued by the Company pursuant to the Indentures related to the Aircraft (as each such Indenture is amended by the Indenture Amendment relating to such Indenture) having the identical interest rate as, and final maturity dates not later than the final Regular Distribution Date of, the Class C Certificates issued hereunder and shall hold such Series C Equipment Notes in trust for the benefit of the Class C Certificateholders;

WHEREAS, pursuant to the Certificate Purchase Agreement, each Purchaser proposes to purchase Class C Certificates issued by the Class C Trust in the face amount set forth opposite the name of such Purchaser on Schedule I thereto on the terms and subject to the conditions set forth therein;



	1	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

WHEREAS, pursuant to the terms and conditions of the Intercreditor Agreement referred to in Section 3.02(i) hereof, the Trustee and the other parties thereto will agree to the terms of subordination set forth therein;

WHEREAS, all of the conditions and requirements necessary to make this Trust Supplement, when duly executed and delivered, a valid, binding and legal instrument in accordance with its terms and for the purposes herein expressed, have been done, performed and fulfilled, and the execution and delivery of this Trust Supplement in the form and with the terms hereof have been in all respects duly authorized;

ARTICLE I

DEFINITIONS

Section 1.01 Definitions . Unless otherwise specified herein or the context otherwise requires, capitalized terms used but not defined herein, including in the recitals hereto, shall have the respective meanings set forth, and shall be construed and interpreted in the manner described, in the Basic Agreement. As used herein, the term “Agreement” shall mean the Basic Agreement, as supplemented by this Trust Supplement. For all purposes of the Basic Agreement as supplemented by this Trust Supplement, the following capitalized terms have the following meanings (any term used herein which is defined in both this Trust Supplement and the Basic Agreement shall have the meaning assigned thereto in this Trust Supplement for purposes of the Basic Agreement as supplemented by this Trust Supplement).

Additional Certificateholder : Has the meaning specified in the Intercreditor Agreement.

Additional Certificates : Has the meaning specified in the Intercreditor Agreement.

Additional Equipment Notes : Has the meaning specified in the Intercreditor Agreement.

Additional Trust : Has the meaning specified in the Intercreditor Agreement.

Additional Trust Agreement : Has the meaning specified in the Intercreditor Agreement.

Affiliate : Has the meaning specified in the Intercreditor Agreement.

Agreement : Has the meaning specified in the first paragraph of Section 1.01 of this Trust Supplement.

Aircraft : Has the meaning specified in the recitals to this Trust Supplement and any Replacement Aircraft (as defined in the applicable Indenture) in replacement thereof in accordance with the applicable Indenture.

Basic Agreement : Has the meaning specified in the preamble to this Trust Supplement.



	2	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Business Day : Has the meaning specified in the Intercreditor Agreement.

Certificate : Means a Class A Certificate, a Class B Certificate or a Class C Certificate, as applicable.

Certificate Buy-Out Event : Has the meaning specified in the Intercreditor Agreement.

Certificate Purchase Agreement : Means the Certificate Purchase Agreement dated as of May 10, 2018 among the Purchasers and Spirit, relating to the purchase of the Class C Certificates by the Purchasers, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

Certificateholder : Means, with respect to any Class of Certificates, the Person in whose name a Certificate is registered in the Register for the Certificates of such Class.

Class : Has the meaning specified in the Intercreditor Agreement.

Class A Certificateholder : Means, at any time, any Certificateholder of one or more Class A Certificates.

Class A Certificates : Has the meaning specified in the Intercreditor Agreement.

Class A Trust : Has the meaning specified in the Intercreditor Agreement.

Class A Trust Agreement : Has the meaning specified in the Intercreditor Agreement.

Class A Trustee : Has the meaning specified in the Intercreditor Agreement.

Class B Certificateholder : Has the meaning specified in the Intercreditor Agreement.

Class B Certificates : Has the meaning specified in the Intercreditor Agreement.

Class B Trust : Has the meaning specified in the Intercreditor Agreement.

Class B Trust Agreement : Has the meaning specified in the Intercreditor Agreement.

Class B Trustee : Has the meaning specified in the Intercreditor Agreement.

Class C Certificateholder : Means, at any time, any Certificateholder of one or more Class C Certificates.

Class C Certificates : Has the meaning specified in Section 3.01 of this Trust Supplement.

Class C Trust : Has the meaning specified in Section 2.01 of this Trust Supplement.

Code : Means the Internal Revenue Code of 1986, as amended.

Company : Has the meaning specified in the preamble to this Trust Supplement.

Corporate Trust Office : Has the meaning specified in the Intercreditor Agreement.



	3	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Definitive Certificates : Has the meaning specified in Section 4.01(e) of this Trust Supplement.

Distribution Date : Means a Regular Distribution Date or a Special Distribution Date.

Equipment Notes : Has the meaning specified in the Intercreditor Agreement.

ERISA : Means the Employee Retirement Income Security Act of 1974, as amended.

ERISA Plan : Means (i) a retirement plan or other employee benefit plan or arrangement, including for this purpose an individual retirement account, annuity or Keogh plan, that is subject to Title I of ERISA or Section 4975 of the Code or (ii) any other entity whose underlying assets are deemed to include the assets of any plan or arrangement described in (i) above by virtue of the U.S. Department of Labor regulation in 29 CFR §2510.3-101, as modified by Section 3(42) of ERISA (or any successor to such regulation).

Event of Default : With respect to any Indenture, has the meaning specified in Section 4.01 of such Indenture.

Fractional Undivided Interests : Has the meaning specified in the Intercreditor Agreement.

Holder : Means a Certificateholder.

Indenture : Has the meaning specified in the Intercreditor Agreement.

Indenture Amendment : Means, with respect to an Indenture and Security Agreement relating to an Aircraft entered into between the Company and the Loan Trustee pursuant to the NPA, the First Amendment thereto, dated as of the date hereof, between the Company and the Loan Trustee.

Indenture Event of Default : Means, with respect to any Indenture, any Event of Default (as such term is defined in such Indenture).

Intercreditor Agreement : Has the meaning specified in Section 3.02(j) of this Trust Supplement.

Issuance Date : Has the meaning specified in Section 7.01(a) of this Trust Supplement.

Junior Additional Certificateholder : Means, with respect to any Additional Certificateholder exercising its right to purchase Certificates under Section 6.01 of this Trust Supplement, any holder of any class of Additional Certificates that rank junior, in priority of payment of “Expected Distributions” for such class under the Intercreditor Agreement, to the class of Additional Certificates held by such Additional Certificateholder.

Liquidity Provider : Has the meaning specified in the Intercreditor Agreement.

Loan Trustee : Means, with respect to any Indenture, the bank, trust company or other financial institution designated as loan trustee thereunder, and any successor to such loan trustee.



	4	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Note Documents : Means, collectively, the Participation Agreements, the Indentures, each Indenture Supplement (as defined in any Indenture), each Manufacturer’s Consent (as defined in any Indenture) and the Equipment Notes.

NPA : Means the Note Purchase Agreement, dated as of August 11, 2015, among the Class A Trustee, the Class B Trustee, the Company, Wilmington Trust Company, as escrow agent, Wilmington Trust, National Association, as paying agent and the Subordination Agent, providing for, among other things, the purchase of Series A Equipment Notes by the Class A Trustee on behalf of the Class A Trust and the purchase of Series B Equipment Notes by the Class B. Trustee on behalf of the Class B Trust, giving effect to the NPA Joinder, as the same may be amended, supplemented or otherwise modified from time to time, in accordance with its terms.

NPA Joinder : Means the Joinder to Note Purchase Agreement, dated as of the date hereof, by Wilmington Trust, National Association, as Trustee, in favor of the Company, the Class A Trustee, the Class B Trustee, the Subordination Agent, the Escrow Agent (as defined in the NPA) and the Paying Agent (as defined in the NPA).

Operative Agreements : Has the meaning specified in the Intercreditor Agreement.

Other Agreements : Means (i) the Class A Trust Agreement, (ii) the Class B Trust Agreement, (iii) any Additional Trust Agreement and (iv) any Refinancing Trust Agreement.

Other Trustees : Means the trustees under the Other Agreements, and any successor or other trustee appointed as provided therein.

Other Trusts : Means the Class A Trust, the Class B Trust, any Additional Trust or Trusts, or any Refinancing Trust or Trusts, in each case created by the applicable Other Agreement.

PA Amendment : Means, with respect to a Participation Agreement relating to an Aircraft entered into by the parties thereto pursuant to the NPA, the First Amendment thereto, dated as of the date hereof, among the initial parties to such Participation Agreement and the Trustee.

Participation Agreement : Has the meaning specified in the Intercreditor Agreement.

Paying Agent : Means, with respect to the Class C Certificates, the paying agent maintained and appointed for such Class C Certificates pursuant to Section 7.12 of the Basic Agreement.

Person : Means any individual, corporation, limited liability company, partnership, joint venture, association, joint-stock company, trust, trustee, unincorporated organization or government or any agency or political subdivision thereof.

Plan : Means (i) an ERISA Plan or (ii) such a plan or arrangement which is a foreign, church or governmental plan or arrangement exempt from Title I of ERISA and Section 4975 of the Code but subject to a Similar Law.

Pool Balance : Means, as of any date, (i) the original aggregate face amount of the Class C Certificates less (ii) the aggregate amount of all distributions made as of such date in respect of the



	5	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Class C Certificates other than distributions made in respect of interest or Premium or reimbursement of any costs or expenses incurred in connection therewith. The Pool Balance as of any date shall be computed after giving effect to the payment of principal, if any, of the Series C Equipment Notes or payment with respect to other Trust Property and the distribution thereof to be made on such date.

Pool Factor : Means, as of any Distribution Date, the quotient (rounded to the seventh decimal place) computed by dividing (i) the Pool Balance by (ii) the original aggregate face amount of the Class C Certificates. The Pool Factor as of any Distribution Date shall be computed after giving effect to payment of principal, if any, of the Series C Equipment Notes or payment with respect to other Trust Property and the distribution thereof to be made on that date.

Premium : Has the meaning specified in the Intercreditor Agreement.

Purchasers : Means the entities named as purchasers of the Class C Certificates in the Certificate Purchase Agreement.

PTC Event of Default : Has the meaning specified in the Intercreditor Agreement.

Rating Agencies : Has the meaning specified in the Intercreditor Agreement.

Refinancing Certificateholder : Has the meaning specified in the Intercreditor Agreement.

Refinancing Certificates : Has the meaning specified in the Intercreditor Agreement.

Refinancing Equipment Notes : Has the meaning specified in the Intercreditor Agreement.

Refinancing Trust : Has the meaning specified in the Intercreditor Agreement.

Refinancing Trust Agreement : Has the meaning specified in the Intercreditor Agreement.

Registrar : Has the meaning specified in Section 4.03 of this Trust Supplement.

Regular Distribution Date : Has the meaning specified in Section 3.02(c) of this Trust Supplement.

Replacement Liquidity Facility : Has the meaning specified in the Intercreditor Agreement.

Replacement Liquidity Provider : Has the meaning specified in the Intercreditor Agreement.

Responsible Officer : Has the meaning specified in the Intercreditor Agreement.

Scheduled Payment : Has the meaning specified in the Intercreditor Agreement.

Securities Act : Means the Securities Act of 1933, as amended.

Series A Equipment Notes : Has the meaning specified in the Intercreditor Agreement.

Series B Equipment Notes : Has the meaning specified in the Intercreditor Agreement.



	6	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Series C Equipment Notes : Has the meaning specified in the Intercreditor Agreement.

Similar Law : Means a foreign, federal, state, or local law which is substantially similar to the prohibited transaction provisions of Title I of ERISA or Section 4975 of the Code.

Special Distribution Date : Means, with respect to the Class C Certificates, each date on which a Special Payment is to be distributed as specified in this Agreement.

Special Payment : Means any payment (other than a Scheduled Payment) in respect of, or any proceeds of, any Equipment Note or the Collateral (as defined in any Indenture).

Special Payments Account : Means, with respect to the Class C Certificates, the account or accounts created and maintained for such series pursuant to Section 4.01(b) of the Basic Agreement (as modified by Section 7.01(c) of this Trust Supplement) and this Trust Supplement.

Spirit : Has the meaning specified in the preamble to this Trust Supplement.

Subordination Agent : Has the meaning specified in the Intercreditor Agreement.

Triggering Event : Has the meaning specified in the Intercreditor Agreement.

Trust : Means the Class A Trust, the Class B Trust or the Class C Trust, as applicable.

Trust Property : Means (i) subject to the Intercreditor Agreement, the Series C Equipment Notes held as the property of the Class C Trust, all monies at any time paid thereon and all monies due and to become due thereunder, (ii) funds from time to time deposited in the Certificate Account and the Special Payments Account and, subject to the Intercreditor Agreement, any proceeds from the sale by the Trustee pursuant to Article VI of the Basic Agreement of any Equipment Notes and (iii) all rights of the Class C Trust and the Trustee, on behalf of the Class C Trust, under the Intercreditor Agreement and the NPA, including, without limitation, all rights to receive certain payments thereunder, and all monies paid to the Trustee on behalf of the Class C Trust pursuant to the Intercreditor Agreement .

Trust Supplement : Has the meaning specified in the preamble hereto.

Trustee : Has the meaning specified in the preamble to this Trust Supplement.

ARTICLE II

DECLARATION OF TRUST

Section 2.01 Declaration of Trust . The Trustee hereby declares the creation of a Trust, designated the “Spirit Airlines Pass Through Trust 2015-1C” (the “Class C Trust”), for the benefit of the Holders of the Class C Certificates to be issued in respect of such Class C Trust, and the initial Holders of the Class C Certificates, as grantors of such Class C Trust, by their respective acceptances of the Class C Certificates, join in the creation of such Class C Trust with the Trustee. The Trustee, by the execution and delivery of this Trust Supplement, acknowledges its acceptance of all right, title and interest in and to the Trust Property to be acquired pursuant to Section 7.01(b) of this Trust Supplement, and the PA Amendments, and the Trustee will hold such right, title and interest for the benefit of all present and future Holders of the Class C Certificates, upon the trusts set forth in the Basic Agreement and this Trust Supplement. The



	7	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

provisions of this Section 2.01 supersede and replace the provisions of Sections 2.03 of the Basic Agreement, with respect to the Class C Trust.

Section 2.02 Permitted Activities . The Class C Trust may only engage in the transactions contemplated by the Operative Agreements, subject to Section 9.05 of this Trust Supplement.

ARTICLE III

THE CERTIFICATES

Section 3.01 The Certificates . There is hereby created a series of Certificates to be issued under this Agreement designated as “Spirit Airlines Pass Through Certificates, Series 2015-1C” (the “Class C Certificates”). Each Class C Certificate represents a Fractional Undivided Interest in the Class C Trust created hereby. The Class C Certificates shall be the only instruments evidencing a Fractional Undivided Interest in the Class C Trust. The Class C Certificates do not represent indebtedness of the Class C Trust, and references herein to interest accruing on the Class C Certificates are included for purposes of computation only.

Section 3.02 Terms and Conditions . The terms and conditions applicable to the Class C Certificates and the Class C Trust are as follows:

(a) The aggregate face amount of the Class C Certificates that may be authenticated and delivered under this Agreement (except for Class C Certificates authenticated and delivered upon registration of transfer of, or in exchange for, or in lieu of, other Class C Certificates pursuant to Sections 3.03, 3.04 and 3.06 of the Basic Agreement and Section 4.03 of this Trust Supplement) is $115,235,000.

(b) [Intentionally omitted]

(c) The distribution dates with respect to any payment of Scheduled Payments (each such distribution date, a “Regular Distribution Date”) shall be April 1 and October 1 of each year, commencing on October 1, 2018, until payment of all of the Scheduled Payments to be made under the Equipment Notes has been made; provided , however , that, if any such day shall not be a Business Day, the related distribution shall be made on the next succeeding Business Day without additional interest. The principal amount of the Series C Equipment Notes to be held by the Class C Trust is scheduled for payment on April 1 and October 1 in certain years, commencing on October 1, 2018 and ending on the applicable date specified under the heading “Maturity Date” on Schedule I to the Indenture Amendment relating to each Aircraft.

(d) The Special Distribution Date with respect to the Class C Certificates means any Business Day on which a Special Payment is to be distributed pursuant to this Agreement.

(e) [Intentionally omitted]

(f) The Class C Certificates shall be in the form attached hereto as Exhibit A and shall be Definitive Certificates.



	8	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

(g) The proceeds of the offering of Class C Certificates issued by the Class C Trust shall be used by the Trustee in accordance with the PA Amendments to acquire on the date hereof the Series C Equipment Notes described in Schedule I to the Indenture Amendment related to each Aircraft.

(h) Any Person acquiring or accepting a Class C Certificate or an interest therein will, by such acquisition or acceptance, be deemed to (i) represent and warrant to the Company, the Loan Trustees and the Trustee that either (1) no assets of a Plan or any trust established with respect to a Plan have been used to purchase or hold Class C Certificates or an interest therein or (2) the purchase and holding of Class C Certificates or interests therein by such Person are exempt from the prohibited transaction restrictions of ERISA and the Code or provisions of Similar Law pursuant to one or more prohibited transaction statutory or administrative exemptions or similar exemptions under Similar Law and (ii) direct the Trustee to invest the assets held in the Class C Trust pursuant to, and take all other actions contemplated by, the terms and conditions of the Basic Agreement, this Trust Supplement, the Intercreditor Agreement, and each PA Amendment.

(i) Any Person who is an ERISA Plan and is acquiring or accepting a Class C Certificate or an interest therein will, by such acquisition or acceptance, be deemed to represent and warrant to the Company, the Loan Trustees and the Trustee, at any time when regulation 29 C.F.R. Section 2510.3-21, as modified in 2016, is applicable that, the decision to acquire or accept the Class C Certificate or interest therein has been made by a duly authorized fiduciary of the ERISA Plan that (i) is independent (as that term is used in 29 C.F.R. 2510.3-21(c)(1))of the Company and its Affiliates and there is no financial interest, ownership interest, or other relationship, agreement or understanding or otherwise that would limit its ability to carry out its fiduciary responsibility to the ERISA Plan; (ii) is a bank, insurance carrier, registered investment adviser, a registered broker-dealer, or an independent fiduciary that holds, or has under management or control, total assets of at least $50 million (in each case, as specified in 29 C.F.R. 2510.3-21(c)(1)(i)(A)-(E)); (iii) is capable of evaluating investment risks independently, both in general and with regard to particular transactions and investment strategies (including, without limitation, with respect to the decision to acquire or accept the Class C Certificate or interest therein); (iv) has been fairly informed that the Company and its Affiliates have not and will not undertake to provide impartial investment advice, or to give advice in a fiduciary capacity, in connection with the acquisition or acceptance of the Class C Certificate or interest therein; (v) has been fairly informed that the Company and its Affiliates have financial interests in the ERISA Plan’s acquisition or acceptance of the Class C Certificate or interest therein, which interests may conflict with the interest of the ERISA Plan, as more fully described in the offering materials; (vi) is a fiduciary under ERISA or the Code, or both, with respect to the decision to acquire or accept the Class C Certificate or interest therein and is responsible for exercising (and has exercised) independent judgment in evaluating whether to invest the assets of the ERISA Plan in the Class C Certificate or interest therein; and (vii) is not paying the Company or any of its Affiliates, any fee or other compensation directly for the provision of investment advice (as opposed to other services) in connection with the ERISA Plan’s acquisition or acceptance of the Class C Certificate or interest therein.



	9	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Trustee and as Class A Trustee and Class B Trustee , Natixis, acting via its New York Branch, as each Liquidity Provider, and Wilmington Trust, National Association, as Subordination Agent thereunder (as may be further amended, supplemented or otherwise modified from time to time in accordance with its terms, the “Intercreditor Agreement”). Under Article VI hereof, the Holders of the Class C Certificates, Additional Certificates (if issued) or Refinancing Certificates (if issued) shall have the rights upon the occurrence of a Certificate Buy Out Event set forth therein. The Trustee and, by acceptance of any Class C Certificate, each Certificateholder thereof, agrees to be bound by all of the provisions of the Intercreditor Agreement, including the subordination provisions of Section 9.09 thereof.

(k) [Intentionally omitted]

(l) The Class C Certificates will not have the benefit of any liquidity facility.

(m) The Responsible Party is the Company.

(n) The Company, any other obligor upon the Class C Certificates, and any Affiliate of any thereof may acquire, tender for, purchase, own, hold, become the pledgee of and otherwise deal with any Class C Certificate.

(o) The “particular sections of the Note Purchase Agreement”, for purposes of clause (3) of Section 7.07 of the Basic Agreement, are Section 4.02 of each Participation Agreement.

ARTICLE IV

ISSUANCE AND TRANSFER OF THE CLASS C CERTIFICATES

Section 4.01 Issuance of Class C Certificates . (a) The Class C Certificates will be issued in minimum denominations of $500,000 and integral multiples of $1,000 in excess thereof, except that one Certificate may be issued in a different denomination. Each Class C Certificate shall be dated the date of its authentication.

(b) [Reserved]

(d) [Reserved]

(e) Certificated Certificates in registered form shall be issued in substantially the form set forth as Exhibit A hereto (the “Definitive Certificates”) and shall be in fully registered form and shall be typed, printed, lithographed or engraved or produced by any combination of these methods or may be produced in any other manner, all as determined by the officers executing such Definitive Certificates, as evidenced by their execution of such Definitive Certificates.

Section 4.02 Legends . Each Class C Certificate shall bear the following legend on the face thereof unless the Company instructs the Trustee otherwise consistent with applicable law:

THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED, OR ANY STATE OR OTHER SECURITIES LAWS. THE HOLDER HEREOF, BY PURCHASING THIS CERTIFICATE, AGREES THAT THIS CERTIFICATE MAY NOT BE OFFERED, RESOLD, PLEDGED OR OTHERWISE TRANSFERRED OTHER THAN (1) TO AN INSTITUTION THAT IS AN “ACCREDITED INVESTOR” AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE SECURITIES ACT IN A TRANSACTION EXEMPT FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT (UPON DELIVERY TO THE TRUSTEE AND THE COMPANY OF AN OPINION OF COUNSEL AND OTHER DOCUMENTATION AS THE TRUSTEE OR THE COMPANY MAY REQUEST), (2) TO A PERSON WHO THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER WITHIN THE MEANING OF RULE 144A UNDER THE SECURITIES ACT PURCHASING FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER IN A TRANSACTION MEETING THE REQUIREMENTS OF RULE 144A, (3) IN AN OFFSHORE TRANSACTION MEETING THE REQUIREMENTS OF RULE 903 OR RULE 904 OF REGULATION S UNDER THE SECURITIES ACT, (4) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT PROVIDED



	10	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

BY RULE 144 OF THE SECURITIES ACT OR ANY SUCCESSOR PROVISION (ASSUMING ANY HOLDING PERIOD DETERMINED THEREUNDER WILL BE DEEMED TO HAVE COMMENCED ON THE MOST RECENT FUNDING DATE), (5) PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, OR (6) TO THE COMPANY AND IN EACH OF THE FOREGOING CASES, IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES OR ANY OTHER JURISDICTION.

BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT EITHER (A) NO ASSETS OF A PLAN OR ANY TRUST ESTABLISHED WITH RESPECT TO A PLAN HAVE BEEN USED TO PURCHASE OR HOLD THIS CERTIFICATE OR (B) THE PURCHASE AND HOLDING OF THIS CERTIFICATE BY SUCH A PERSON ARE EXEMPT FROM THE PROHIBITED TRANSACTION RESTRICTIONS OF ERISA AND THE CODE OR PROVISIONS OF SIMILAR LAW PURSUANT TO ONE OR MORE PROHIBITED TRANSACTION STATUTORY OR ADMINISTRATIVE EXEMPTIONS OR SIMILAR EXEMPTIONS UNDER SIMILAR LAW.

BY ITS ACQUISITION HEREOF, A HOLDER WHO IS AN ERISA PLAN REPRESENTS, AT ANY TIME WHEN REGULATION 29 C.F.R. SECTION 2510.3-21, AS MODIFIED IN 2016, IS APPLICABLE, THAT THE DECISION TO ACQUIRE OR ACCEPT THIS CERTIFICATE HAS BEEN MADE BY A DULY AUTHORITZED FIDUCIARY OF THE ERISA PLAN THAT (A) IS INDEPENDENT (AS THAT TERM IS USED IN 29 C.F.R. 2510-3-21(c)(1)) OF THE COMPANY AND ITS AFFILIATES AND THERE IS NO FINANCIAL INTEREST, OWNERSHIP INTEREST, OR OTHER RELATIONSHIP, AGREEMENT OR UNDERSTANDING OR OTHERWISE THAT WOULD LIMIT ITS ABILITY TO CARRY OUT ITS FIDUCIARY RESPONSIBILITY TO THE ERISA PLAN; (B) IS A BANK, INSURANCE CARRIER, REGISTERED INVESTMENT ADVISER, A REGISTERED BROKER-DEALER, OR AN INDEPENDENT FIDUCIARY THAT HOLDS, OR HAS UNDER MANAGEMENT OR CONTROL, TOTAL ASSETS OF AT LEAST $50 MILLION (IN EACH CASE, AS SPECIFIED IN 29 C.F.R. 2510.3-21(c)(1)(i)(A)-(E)); (C) IS CAPABLE OF EVALUATING INVESTMENT RISKS INDEPENDENTLY, BOTH IN GENERAL AND WITH REGARD TO PARTICULAR TRANSACTIONS AND INVESTMENT STRATEGIES (INCLUDING, WITHOUT LIMITATION, WITH RESPECT TO THE DECISION TO ACQUIRE OR ACCEPT THIS CERTIFICATE); (D) HAS BEEN FAIRLY INFORMED THAT THE COMPANY AND ITS AFFILIATES HAVE NOT AND WILL NOT UNDERTAKE TO PROVIDE IMPARTIAL INVESTMENT ADVICE, OR TO GIVE ADVICE IN A FIDUCIARY CAPACITY, IN CONNECTION WITH THE ACQUISITION OR ACCEPTANCE OF THIS CERTIFICATE; (E) HAS BEEN FAIRLY INFORMED THAT THE COMPANY AND ITS AFFILIATES HAVE FINANCIAL INTERESTS IN THE ERISA PLAN’S ACQUISITION OR ACCEPTANCE OF THIS CERTIFICATE, WHICH INTERESTS MAY CONFLICT WITH THE INTEREST OF THE ERISA PLAN, AS MORE FULLY DESCRIBED IN THE OFFERING MATERIALS; (F) IS A FIDUCIARY UNDER ERISA OR THE CODE, OR



	11	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

BOTH, WITH RESPECT TO THE DECISION TO ACQUIRE OR ACCEPT THIS CERTIFICATE AND IS RESPONSIBLE FOR EXERCISING (AND HAS EXERCISED) INDEPENDENT JUDGMENT IN EVALUATING WHETHER TO INVEST THE ASSETS OF THE ERISA PLAN IN THIS CERTIFICATE; AND (G) IS NOT PAYING FOR THE COMPANY OR ANY OF ITS AFFILIATES, ANY FEE OR OTHER COMPENSATION DIRECTLY FOR THE PROVISION OF INVESTMENT ADVICE (AS OPPOSED TO OTHER SERVICES) IN CONNECTION WITH THE ERISA PLAN’S ACQUISITION OR ACCEPTANCE OF THIS CERTIFICATE.

CERTAIN TERMS USED IN THE FOREGOING PARAGRAPHS SHALL HAVE THE MEANINGS SPECIFIED IN THE AGREEMENT.

Section 4.03 Transfer and Exchange . The Registrar shall cause to be kept at the office or agency to be maintained by it in accordance with the provisions of Section 7.12 of the Basic Agreement a register (the “Register”) for the Class C Certificates in which, subject to such reasonable regulations as it may prescribe, the Registrar shall provide for the registration of Certificates of such series and of transfers and exchanges of such Class C Certificates as herein provided. The Trustee shall initially be the registrar (the “Registrar”) for the purpose of registering such Class C Certificates and transfers and exchanges of such Class C Certificates as herein provided.

All Class C Certificates issued upon any registration of transfer or exchange of Class C Certificates shall be valid obligations of the Class C Trust, evidencing the same interest therein, and entitled to the same benefits under this Agreement, as the Class C Certificates surrendered upon such registration of transfer or exchange.

Upon surrender for registration of transfer or exchange of any Class C Certificate at the Corporate Trust Office or such other office or agency, the Trustee shall execute, authenticate and deliver, in the name of the designated transferee or transferees, one or more new Class C Certificates, in authorized denominations of a like aggregate Fractional Undivided Interest.

A Class C Certificateholder may transfer a Class C Certificate, or request that a Class C Certificate be exchanged for Class C Certificates in an aggregate Fractional Undivided Interest equal to the Fractional Undivided Interest of such Class C Certificate surrendered for exchange of other authorized denominations, by surrender of such Class C Certificate to the Trustee with the form of transfer notice thereon duly completed and executed, and otherwise complying with the terms of the Agreement, including providing evidence of compliance with any restrictions on transfer, in form satisfactory to the Trustee and the Registar. No such transfer shall be effected until, and such transferee shall succeed to the rights of a Class C Certificateholder only upon, final acceptance and registration of the transfer by the Registrar in the Register. Prior to the registration of any transfer by a Class C Certificateholder as provided herein, the Trustee shall treat the Person in whose name the Class C Certificate is registered as the owner thereof for all purposes, and the Trustee shall not be affected by notice to the contrary.



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Exhibit 4.2

the Company has so notified the Trustee and the Registrar in writing of such satisfaction. The Registrar and the Trustee shall not be liable to any Person for registering any transfer or exchange, or for executing, authenticating or delivering any Class C Certificate based on such certification. The Registrar and the Trustee may treat the Person in whose name any Class C Certificate is registered as the sole owner of the beneficial interest in the Class C Trust evidenced by such Class C Certificate.

By its acceptance of a Class C Certificate, each Holder of Class C Certificates acknowledges the restrictions on transfer of the Class C Certificates set forth in this Trust Supplement and in the legend on the face thereof and agrees that it will transfer such Class C Certificates only as provided in this Trust Supplement and in the legend on the face thereof.

No service charge shall be made to a Class C Certificateholder for any registration of transfer or exchange of Class C Certificates, but the Registrar shall require payment of a sum sufficient to cover any tax or governmental charge that may be imposed in connection with any transfer or exchange of Class C Certificates. All Class C Certificates surrendered for registration of transfer or exchange shall be cancelled and subsequently destroyed by the Trustee.

Section 4.04 Amendment of Section 3.04 and Inapplicability of Section 3.05 for the Basic Agreement . Section 4.03 of this Trust Supplement supersedes and replaces Section 3.04 of the Basic Agreement with respect to the Class C Trust and, for purposes of this Agreement, any references in the Basic Agreement to Section 3.04 of the Basic Agreement shall be superseded and replaced by a reference to Section 4.03 of this Trust Supplement. Pursuant to Section 3.05(f) of the Basic Agreement, Section 3.05 thereof is inapplicable to the Class C Certificates and this Trust Supplement.

ARTICLE V

DISTRIBUTION; STATEMENTS TO CERTIFICATEHOLDERS

Section 5.01 Statements to Certificateholders . (a) On each Regular Distribution Date and Special Distribution Date, the Trustee will include with each distribution to the Class C Certificateholders a statement, giving effect to the distribution to be made on such Regular Distribution Date or Special Distribution Date, setting forth the following information (per $1,000 aggregate face amount of Class C Certificates as to clauses (ii) and (iii)):

(i) the aggregate amount of funds distributed on such Distribution Date under this Agreement, indicating the amount, if any, allocable to each source;

(ii) the amount of such distribution under this Agreement allocable to principal and the amount allocable to Premium (if any);

(iii) the amount of such distribution under this Agreement allocable to interest; and

(iv) the Pool Balance and the Pool Factor.



	13	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

determined pursuant to clauses (a)(i), (a)(ii) and (a)(iii) above for such calendar year or, in the event such Person was a Class C Certificateholder of record during a portion of such calendar year, for the applicable portion of such year, and such other items as are readily available to the Trustee and which a Class C Certificateholder may reasonably request as necessary for the purpose of such Certificateholder’s preparation of its United States federal income tax returns or foreign income tax returns.

(i) [Intentionally omitted]

(ii) the date of any early redemption or purchase of, or any default in the payment of principal or interest in respect of, any of the Series C Equipment Notes held in the Class C Trust.

the Trustee shall furnish to Class C Certificateholders of record on such date a statement setting forth (x) the expected Pool Balances for each subsequent Regular Distribution Date following the date of such early redemption, purchase or default, (y) the related Pool Factors for such Regular Distribution Dates and (z) the expected principal distribution schedule of the Series C Equipment Notes, in the aggregate, held as Trust Property at the date of such notice.

(d) Notwithstanding anything to the contrary herein or in the Basic Agreement, to the extent a Class C Certificateholder has provided in writing sufficient wire transfer details to the Trustee, each distribution on the Class C Certificates to such Certificateholder shall be made by wire transfer in immediately available funds to the account designated by such Certificateholder.

(e) The provisions of this Section 5.01 supersede and replace the provisions of Section 4.03 of the Basic Agreement in their entirety with respect to the Class C Trust.

ARTICLE VI

DEFAULT

Section 6.01 Purchase Rights of Certificateholders . (a) By acceptance of its Class C Certificate, each Class C Certificateholder agrees that at any time after the occurrence and during the continuation of a Certificate Buy-Out Event:



	14	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

period, provided that (A) if prior to the end of such ten-day period any other Class C Certificateholder(s) (other than the Company or any of its Affiliates) notifies such purchasing Class C Certificateholder that such other Class C Certificateholder(s) want(s) to participate in such purchase, then such other Class C Certificateholder(s) (other than the Company or any of its Affiliates) may join with the purchasing Class C Certificateholder to purchase all, but not less than all, of the Class A Certificates and the Class B Certificates pro rata based on the Fractional Undivided Interest in the Class C Trust held by each such Class C Certificateholder and (B) upon consummation of such purchase no Class C Certificateholder shall have a right to purchase the Class A Certificates and the Class B Certificates pursuant to this Section 6.01(a)(i) during the continuance of such Certificate Buy-Out Event,

(ii) if any Additional Certificates are issued by an Additional Trust, so long as no Junior Additional Certificateholder (if any) has elected to exercise its rights to purchase Certificates pursuant to, and given notice of such election in accordance with, this Section 6.01(a) (upon such election and notification thereof, the right specified in this Section 6.01(a)(ii) shall be suspended and (x) upon consummation of the purchase pursuant to such election, be terminated with respect to such Certificate Buy-Out Event, or (y) upon failure to consummate such purchase on the proposed purchase date, such right shall be revived), each Additional Certificateholder (other than the Company or any of its Affiliates) shall have the right (which shall not expire upon any purchase of the Class A Certificates and the Class B Certificates pursuant to clause (i) above) to purchase all, but not less than all, of the Class A Certificates, the Class B Certificates, the Class C Certificates and any Additional Certificates ranked senior, in priority of payment of “Expected Distributions” therefor under the Intercreditor Agreement, to the Additional Certificates held by the purchasing Additional Certificateholder upon ten days’ prior written irrevocable notice to the Trustee, the Class A Trustee, the Class B Trustee, the trustee of any Additional Trust with respect to any Additional Certificates that rank senior, in priority of payment of “Expected Distributions” therefor under the Intercreditor Agreement, to the Additional Certificates held by the purchasing Additional Certificateholder and each other Additional Certificateholder of the same class, on the third Business Day following the expiration of such ten-day notice period, provided that (A) if prior to the end of such ten-day period any other Additional Certificateholder(s) of such class (other than the Company or any of its Affiliates) notifies such purchasing Additional Certificateholder that such other Additional Certificateholder(s) want(s) to participate in such purchase, then such other Additional Certificateholder(s) (other than the Company or any of its Affiliates) may join with the purchasing Additional Certificateholder to purchase all, but not less than all, of the Class A Certificates, the Class B Certificates, the Class C Certificates and such senior Additional Certificates pro rata based on the Fractional Undivided Interest in the applicable Additional Trust held by each such Additional Certificateholder and (B) upon consummation of such purchase no Additional Certificateholder of such class shall have a right to purchase the Class A Certificates, the Class B Certificates, the Class C Certificates and such senior Additional Certificates pursuant to this Section 6.01(a)(ii) during the continuance of such Certificate Buy-Out Event, and

(iii) if any Refinancing Certificates are issued, each Refinancing Certificateholder shall have the same right (subject to the same terms and conditions) to purchase Certificates pursuant to



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Exhibit 4.2

this Section 6.01(a) (and to receive notice in connection therewith) as the Holders of the Class that such Refinancing Certificates refinanced.

The purchase price with respect to the Class C Certificates shall be equal to the Pool Balance of the Class C Certificates, together with accrued and unpaid interest in respect thereof to the date of such purchase, and any other amounts then due and payable to the Class C Certificateholders under this Agreement, the Intercreditor Agreement, any Series C Equipment Note held as the property of the Class C Trust or the related Indenture and Participation Agreement or on or in respect of the Class C Certificates but without any Premium, provided , however , that if such purchase occurs after the Record Date relating to any Distribution Date, such purchase price shall be reduced by the amount to be distributed hereunder on such related Distribution Date (which deducted amounts shall remain distributable to, and may be retained by, the Class C Certificateholders as of such Record Date); provided further that no such purchase of Class C Certificates pursuant to this Section 6.01(a) shall be effective unless the purchaser(s) shall certify to the Trustee that contemporaneously with such purchase, such purchaser(s) is purchasing, pursuant to the terms of this Agreement, the Class A Trust Agreement, the Class B Trust Agreement, the applicable Additional Trust Agreement (if any) or the applicable Refinancing Trust Agreement (as the case may be), and the Intercreditor Agreement, all of the Class A Certificates, the Class B Certificates, the Class C Certificates and, if applicable, the Additional Certificates that rank senior, in priority of payment of “Expected Distributions” therefor under the Intercreditor Agreement, to the Additional Certificates held by the purchasing Additional Certificateholder(s) and, if applicable, the Refinancing Certificates that are senior to the securities held by such purchaser(s). Each payment of the purchase price of the Class C Certificates referred to in the first sentence of this paragraph shall be made to an account or accounts designated by the Trustee and each such purchase shall be subject to the terms of this Section 6.01(a). Each Class C Certificateholder agrees by its acceptance of its Class C Certificate that it will, upon payment from such Additional Certificateholder(s) or Refinancing Certificateholder(s), as the case may be, of the purchase price set forth in the first sentence of this paragraph, forthwith sell, assign, transfer and convey to the purchaser(s) thereof (without recourse, representation or warranty of any kind except as to its own acts) all of the right, title, interest and obligation of such Class C Certificateholder in this Agreement, the Intercreditor Agreement, the NPA, the Note Documents and all Class C Certificates held by such Class C Certificateholder (excluding all right, title and interest under any of the foregoing to the extent such right, title or interest is with respect to an obligation not then due and payable as respects any action or inaction or state of affairs occurring prior to such sale) and the purchaser(s) shall assume all of such Class C Certificateholder’s obligations under this Agreement, the Intercreditor Agreement, the NPA, the Note Documents and all such Class C Certificates. The Class C Certificates will be deemed to be purchased on the date payment of the purchase price is made notwithstanding the failure of any Class C Certificateholder to deliver any Class C Certificate and, upon such a purchase, (i) the Class C Certificateholders shall have no further rights with respect to the Class C Certificates and (ii) if the purchaser(s) shall so request, each such Class C Certificateholder will comply with all the provisions of Section 3.04 of the Basic Agreement and the applicable provisions of this Trust Supplement to enable new Class C Certificates to be issued to the purchaser(s) in such denominations otherwise authorized under this Agreement as it shall request. All charges and expenses in connection with the issuance of any such new Class C Certificates shall be borne by the purchaser(s) thereof.



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Exhibit 4.2

(b) This Section 6.01 supplements and, to the extent inconsistent with any provision of Section 6.01(b) of the Basic Agreement, replaces the provisions of Section 6.01(b) of the Basic Agreement. Notwithstanding anything to the contrary set forth herein or in any Operative Agreement, the provisions of this Section 6.01 may not be amended in any manner without the consent of each Class A Certificateholder, each Class B Certificateholder, each Class C Certificateholder and each Additional Certificateholder (if any) or, as the case may be, Refinancing Certificateholder (if any) (in each case, other than the Company or any of its Affiliates in its respective capacity as a Certificateholder) that would be adversely affected thereby; provided that the purchase price under this Section 6.01 (as in effect on the date hereof) for any Certificate held by the Company or any of its Affiliates shall not be modified without the prior written consent of the Company. For the avoidance of doubt, if a Certificate Buy-Out Event ceases to exist and another Certificate Buy-Out Event occurs and is continuing, the purchase rights set forth in Section 6.01(a) shall be revived notwithstanding any exercise of such rights during the continuance of any preceding Certificate Buy-Out Event.

ARTICLE VII

THE TRUSTEE

Section 7.01 Delivery of Documents; Delivery Dates . (a) The Trustee is hereby directed (i) to execute and deliver the Intercreditor Agreement, the NPA Joinder, and the PA Amendments on or prior to the date of the initial issuance of the Class C Certificates (the “Issuance Date”), each in the form delivered to the Trustee by the Company, and (ii) subject to the respective terms thereof, to perform its obligations under the Intercreditor Agreement, the NPA, the NPA Joinder and the Participation Agreements. Upon request of the Company and the satisfaction or waiver of the closing conditions specified in the Certificate Purchase Agreement, the Trustee shall execute, deliver, authenticate, issue and sell Class C Certificates in authorized denominations equaling in the aggregate the amount set forth, with respect to the Class C Trust, in Schedule I to the Certificate Purchase Agreement evidencing the entire ownership interest in the Class C Trust, which amount equals the maximum aggregate principal amount of Series C Equipment Notes to be purchased on the date hereof by the Trustee pursuant to the PA Amendments. Except as provided in Sections 3.03, 3.04 and 3.06 of the Basic Agreement or Section 4.03 of this Trust Supplement, the Trustee shall not execute, authenticate or deliver Class C Certificates in excess of the aggregate amount specified in this paragraph. The provisions of this Section 7.01(a) supersede and replace the first three sentences of Section 2.02(a) of the Basic Agreement and the first sentence of Section 3.02(a) of the Basic Agreement, with respect to the Class C Trust.

(b) On the Issuance Date, upon satisfaction of the conditions set forth in each PA Amendment, the Trustee shall purchase the Series C Equipment Notes to be purchased thereunder. The purchase price of such Series C Equipment Notes shall equal the principal amount of such Series C Equipment Notes. No provisions of the Basic Agreement relating to Postponed Notes and Section 2.02(b) of the Basic Agreement shall apply to the Class C Trust.



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Exhibit 4.2

be non-interest bearing except as provided in Section 4.04 of the Basic Agreement. The Trustee shall hold the Special Payments Account in trust for the benefit of the Class C Certificateholders and shall make or permit withdrawals therefrom only as provided in the Agreement or the Intercreditor Agreement. On each day when one or more Special Payments are made to the Trustee under the Intercreditor Agreement, the Trustee, upon receipt thereof, shall immediately deposit the aggregate amount of such Special Payments in the Special Payments Account.”

(d) With respect to the Class C Trust, the second through fifth sentences of Section 4.02(c) of the Basic Agreement shall be superseded and replaced in their entirety with the following sentence: “Subject to the provisions of the Intercreditor Agreement: (i) in the event of redemption or purchase of Series C Equipment Notes held in the Class C Trust, such notice shall be mailed not less than 15 days prior to the Special Distribution Date for the Special Payment resulting from such redemption or purchase, which Special Distribution Date shall be the date of such redemption or purchase; and (ii) in the case of any other Special Payments, such notice of Special Payment shall be mailed as soon as practicable after the Trustee has confirmed that it has received funds for such Special Payment and shall state the Special Distribution Date for such Special Payment, which shall occur 15 days after the date of such notice of Special Payment or (if such 15th day is not practicable) as soon as practicable thereafter.”

(e) With respect to the Class C Trust, clause (ii) of the sixth sentence of Section 4.02(c) of the Basic Agreement shall be amended by deleting in its entirety the parenthetical phrase “(taking into account any payment to be made by the Company pursuant to Section 2.02(b)).”

Section 7.02 [Intentionally omitted]

Section 7.03 The Trustee . (a) Subject to Section 7.04 of this Trust Supplement and Section 7.15 of the Basic Agreement, the Trustee shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Trust Supplement, the Intercreditor Agreement, the NPA or the NPA Joinder or the due execution hereof or thereof by the Company or the other parties thereto (other than the Trustee), or for or in respect of the recitals and statements contained herein or therein, all of which recitals and statements are made solely by the Company or the other parties thereto (other than the Trustee), except that the Trustee hereby represents and warrants that each of this Trust Supplement, the Basic Agreement, each Class C Certificate, the Intercreditor Agreement and the NPA Joinder has been executed and delivered by one of its officers who is duly authorized to execute and deliver such document on its behalf.

(b) In addition to the requirements in Section 7.08 of the Basic Agreement, the Trustee shall at all times be a bank or trust company, organized and doing business under the laws of the United States or any state thereof, a substantial part of the business of which consists of (i) receiving deposits and making loans or (ii) exercising fiduciary powers similar to those permitted to national banks by the Comptroller of the Currency, and which is subject to supervision and examination by state or federal authority having supervision over banking institutions.



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Exhibit 4.2

Section 7.04 Representations and Warranties of the Trustee . The Trustee hereby represents and warrants that:

(a) the Trustee (i) has full power, authority and legal right to (x) execute, deliver and perform this Trust Supplement, the Intercreditor Agreement, the NPA Joinder, the Class C Certificates and the Note Documents to which it is or is to become a party and (y) perform the NPA and (ii) has taken all necessary action to authorize (x) the execution, delivery and performance by it of this Trust Supplement, the Intercreditor Agreement, the NPA Joinder, the Class C Certificates and the Note Documents to which it is or is to become a party and (y) the performance by the Trustee of the NPA;

(b) (i) the execution, delivery and performance by the Trustee of this Trust Supplement, the Intercreditor Agreement, the NPA Joinder, the Class C Certificates and the Note Documents to which it is or is to become a party and (ii) the performance by the Trustee of the NPA (x) will not violate any provision of any United States federal law governing its banking powers or the law of the state of the United States where it is located governing the banking and trust powers of the Trustee or any order, writ, judgment, or decree of any court, arbitrator or governmental authority applicable to the Trustee or any of its assets, (y) will not violate any provision of the articles of association or by-laws of the Trustee, and (z) will not violate any provision of, or constitute, with or without notice or lapse of time, a default under, or result in the creation or imposition of any lien on any properties included in the Trust Property pursuant to the provisions of, any mortgage, indenture, contract, agreement or other undertaking to which it is a party, which violation, default or lien could reasonably be expected to have an adverse effect on the Trustee’s performance or ability to perform its duties hereunder or thereunder or on the transactions contemplated herein or therein;

(c) (i) the execution, delivery and performance by the Trustee of this Trust Supplement, the Intercreditor Agreement, the NPA Joinder, the Class C Certificates and the Note Documents to which it is or is to become a party and (ii) the performance by the Trustee of the NPA will not require the authorization, consent, or approval of, the giving of notice to, the filing or registration with, or the taking of any other action in respect of, any governmental authority or agency of the United States or the state of the United States where it is located regulating the banking and corporate trust activities of the Trustee; and

(d) this Trust Supplement, the Intercreditor Agreement, the NPA, the NPA Joinder, the Class C Certificates and the Note Documents to which it is or is to become a party have been, or will be, as applicable, duly executed and delivered by the Trustee and constitute, or will constitute, as applicable, the legal, valid and binding agreements of the Trustee, enforceable against it in accordance with their respective terms; provided , however , that enforceability may be limited by (i) applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting the rights of creditors generally and (ii) general principles of equity.

Section 7.05 Trustee Liens . The Trustee in its individual capacity agrees, in addition to the agreements contained in Section 7.17 of the Basic Agreement, that it will at its own cost and expense promptly take any action as may be necessary to duly discharge and satisfy in full any Trustee’s Liens on or with respect to the Trust Property which are attributable to the Trustee in its individual capacity and which are unrelated to the transactions contemplated by the Intercreditor Agreement or the NPA.



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Exhibit 4.2

ARTICLE VIII

ADDITIONAL AMENDMENT; SUPPLEMENTAL AGREEMENTS

Section 8.01 Amendment of Sections 5.02, 6.07, 7.09, 8.04, 9.01, 12.01 and 12.02 of the Basic Agreement . For purposes of this Agreement, the Basic Agreement shall be deemed amended as follows:

(a) Section 5.02 of the Basic Agreement shall be deemed amended and restated in its entirety to read as set forth in Part A of Exhibit B.

(b) Section 6.07 of the Basic Agreement shall be deemed amended and restated in its entirety to read as set forth in Part B of Exhibit B.

(c) Section 7.09 of the Basic Agreement shall be deemed amended by amending and restating the second sentence of subsection (e) thereof in its entirety to read as set forth in Part C of Exhibit B.

(d) Section 8.04 of the Basic Agreement shall be deemed amended by amending and restating subsection (a) thereof in its entirety to read as set forth in Part D of Exhibit B.

(e) Section 9.01 of the Basic Agreement shall be deemed amended by amending and restating clause (4) thereof in its entirety to read as set forth in Part E of Exhibit B.

(f) Section 12.01 of the Basic Agreement shall be deemed amended and restated in its entirety to read as set forth in Part F of Exhibit B.

(g) Section 12.02 of the Basic Agreement shall be deemed amended and restated in its entirety to read as set forth in Part G of Exhibit B.



	20	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

in Section 4(a)(v) of the NPA and Section 8.01(d) of the Intercreditor Agreement, and (iii) one or more agreements supplemental to any Operative Agreement or the NPA to provide for the formation of one or more Refinancing Trusts, the issuance of one or more Classes of Refinancing Certificates, the purchase by any Refinancing Trust of applicable Refinancing Equipment Notes and other matters incidental thereto or as otherwise contemplated by Section 2.01(b) of the Basic Agreement, all as provided in Section 4(a)(v) of the NPA and Section 8.01(c) of the Intercreditor Agreement. In addition, the following provisions of Section 9.01 of the Basic Agreement shall be amended, with respect to the Class C Trust, as follows: (A) [Reserved]; (B) Section 9.01(6) of the Basic Agreement shall be amended by inserting the phrase “to establish or” after the phrase “to such extent as shall be necessary” but before the phrase “to continue”; and (C) Section 9.01(7) of the Basic Agreement shall be amended by replacing the phrase “and to add to or change” with the phrase “, or to evidence the substitution of a Liquidity Provider with a Replacement Liquidity Provider or to provide for a Replacement Liquidity Facility, all as provided in any Intercreditor Agreement; or to provide multiple Liquidity Facilities with respect to one or more Trusts; or to add to or change”.

Section 8.04 Consent of Trustees for Amendment of Section 6.01 . Notwithstanding any provision in Section 8.02 or Section 8.03 of this Trust Supplement to the contrary, no amendment or modification of Section 6.01 of this Trust Supplement shall be effective unless the trustee for each Class of Certificates affected by such amendment or modification shall have consented thereto.

ARTICLE IX

MISCELLANEOUS PROVISIONS

Section 9.01 Final Termination Date . The respective obligations and responsibilities of the Company and the Trustee created hereby and the Class C Trust created hereby shall terminate upon the distribution to all Class C Certificateholders and the Trustee of all amounts required to be distributed to them pursuant to this Agreement and the disposition of all property held as part of the Trust Property; provided, however, that in no event shall the Trust created hereby continue beyond the expiration of 21 years from the death of the last survivor of the descendants of Joseph P. Kennedy, Sr., the father of John F. Kennedy, former President of the United States, living on the date of this Trust Supplement.

Notice of any termination of the Class C Trust, specifying the applicable Regular Distribution Date (or applicable Special Distribution Date, as the case may be) upon which the Class C Certificateholders may surrender their Class C Certificates to the Trustee for payment of the final distribution and cancellation, shall be mailed promptly by the Trustee to the Class C Certificateholders not earlier than 60 days and not later than 15 days preceding such final distribution.

Section 9.02 Basic Agreement Ratified . Except and so far as herein expressly provided, all of the provisions, terms and conditions of the Basic Agreement are in all respects ratified and confirmed;



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Exhibit 4.2

and the Basic Agreement and this Trust Supplement shall be taken, read and construed as one and the same instrument. To the extent that any provisions of the Basic Agreement are superseded by any provisions of this Trust Supplement, any reference to such provisions of the Basic Agreement herein or in the Basic Agreement shall be deemed to be to such provisions of this Trust Supplement.

Section 9.03 Governing Law . THIS AGREEMENT HAS BEEN DELIVERED IN THE STATE OF NEW YORK AND THIS AGREEMENT AND THE CLASS C CERTIFICATES SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

Section 9.04 Counterparts . This Trust Supplement may be executed in any number of counterparts (and each of the parties shall not be required to execute the same counterpart). Each counterpart of this Trust Supplement including a signature page or pages executed by each of the parties hereto shall be an original counterpart of this Trust Supplement, but all of such counterparts together shall constitute one instrument.

Section 9.05 Intention of Parties . The parties hereto intend that the Class C Trust be classified for United States federal income tax purposes as a grantor trust under Subpart E, Part I, Subchapter J, Chapter 1 of Subtitle A of the Code, and not as a trust or association taxable as a corporation or as a partnership. Each Certificateholder of, and each Person acquiring a beneficial interest in, a Class C Certificate, by its acceptance of its Class C Certificate or a beneficial interest therein, agrees to treat the Class C Trust as a grantor trust for all United States federal, state and local income tax purposes. The Trustee shall not be authorized or empowered to do anything that would cause the Class C Trust to fail to qualify as a grantor trust for such tax purposes (including as subject to this restriction, acquiring any Aircraft by bidding the Equipment Notes relating thereto or otherwise, or taking any action with respect to any such Aircraft once acquired).

Section 9.06 Submission to Jurisdiction. Each of the parties hereto, to the extent it may do so under applicable law, for purposes hereof and of all other Operative Agreements hereby (i) irrevocably submits itself to the non-exclusive jurisdiction of the courts of the State of New York sitting in the City of New York and to the non-exclusive jurisdiction of the United States District Court for the Southern District of New York, for the purposes of any suit, action or other proceeding arising out of this Agreement, the subject matter hereof or any of the transactions contemplated hereby brought by any party or parties hereto or thereto, or their successors or permitted assigns and (ii) waives, and agrees not to assert, by way of motion, as a defense, or otherwise, in any such suit, action or proceeding, that the suit, action or proceeding is brought in an inconvenient forum, that the venue of the suit, action or proceeding is improper or that this Agreement or the subject matter hereof or any of the transactions contemplated hereby may not be enforced in or by such courts.

Section 9.07 Successor and Assigns . All covenants, agreements, representations and warranties in this Agreement by the Trustee and the Company shall bind and, to the extent permitted hereby, shall inure to the benefit of and be enforceable by their respective successors and assigns, whether so expressed or not. Any request, notice, direction, consent, waiver or other instrument or action by any Class C Certificateholder shall bind the successors and assigns of such Class C Certificateholder.



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Exhibit 4.2

Section 9.08 Normal Commercial Relations . Anything contained in this Agreement to the contrary notwithstanding, the Trustee and any Class C Certificateholder, or any bank or other affiliate of any such party, may conduct any banking or other financial transactions, and have banking and other commercial relationships, with the Company fully to the same extent as if this Agreement were not in effect, including without limitation the making of loans or other extensions of credit to the Company for any purpose whatsoever, whether related to any of the transactions contemplated hereby or otherwise.

Section 9.09 No Recourse against Others . No past, present or future director, officer, employee, agent, member, manager, trustee or stockholder, as such, of the Company or any successor Person shall have any liability for any obligations of the Company or any successor Person, either directly or through the Company or any successor Person, under the Class C Certificates or this Agreement or for any claim based on, in respect of or by reason of such obligations or their creation, whether by virtue of any rule of law, statute or constitutional provision of by the enforcement of any assessment or by any legal or equitable proceeding or otherwise. By accepting a Class C Certificate, each Class C Certificateholder agrees to the provisions of this Section 9.09 and waives and releases all such liability. Such waiver and release shall be part of the consideration for the issue of the Class C Certificates.

[ Remainder of Page Intentionally Blank; Signature Pages Follow ]

IN WITNESS WHEREOF, the parties have caused this Trust Supplement to be duly executed by their respective officers thereto duly authorized as of the date first written above.

SPIRIT AIRLINES, INC.


By:	/s/ Edward Christie Name: Edward Christie Title: President and Chief Financial Officer



	23	Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Trustee


By:	/s/ Jacqueline Solone Name: Jacqueline Solone Title: Vice President

Signature Page



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

EXHIBIT A to
TRUST SUPPLEMENT NO. 2015-1C

FORM OF CERTIFICATE



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

REGISTERED BROKER-DEALER, OR AN INDEPENDENT FIDUCIARY THAT HOLDS, OR HAS UNDER MANAGEMENT OR CONTROL, TOTAL ASSETS OF AT LEAST $50 MILLION (IN EACH CASE, AS SPECIFIED IN 29 C.F.R. 2510.3-21(c)(1)(i)(A)-(E)); (C) IS CAPABLE OF EVALUATING INVESTMENT RISKS INDEPENDENTLY, BOTH IN GENERAL AND WITH REGARD TO PARTICULAR TRANSACTIONS AND INVESTMENT STRATEGIES (INCLUDING, WITHOUT LIMITATION, WITH RESPECT TO THE DECISION TO ACQUIRE OR ACCEPT THIS CERTIFICATE); (D) HAS BEEN FAIRLY INFORMED THAT THE COMPANY AND ITS AFFILIATES HAVE NOT AND WILL NOT UNDERTAKE TO PROVIDE IMPARTIAL INVESTMENT ADVICE, OR TO GIVE ADVICE IN A FIDUCIARY CAPACITY, IN CONNECTION WITH THE ACQUISITION OR ACCEPTANCE OF THIS CERTIFICATE; (E) HAS BEEN FAIRLY INFORMED THAT THE COMPANY AND ITS AFFILIATES HAVE FINANCIAL INTERESTS IN THE ERISA PLAN’S ACQUISITION OR ACCEPTANCE OF THIS CERTIFICATE, WHICH INTERESTS MAY CONFLICT WITH THE INTEREST OF THE ERISA PLAN, AS MORE FULLY DESCRIBED IN THE OFFERING MATERIALS; (F) IS A FIDUCIARY UNDER ERISA OR THE CODE, OR BOTH, WITH RESPECT TO THE DECISION TO ACQUIRE OR ACCEPT THIS CERTIFICATE AND IS RESPONSIBLE FOR EXERCISING (AND HAS EXERCISED) INDEPENDENT JUDGMENT IN EVALUATING WHETHER TO INVEST THE ASSETS OF THE ERISA PLAN IN THIS CERTIFICATE; AND (G) IS NOT PAYING FOR THE COMPANY OR ANY OF ITS AFFILIATES, ANY FEE OR OTHER COMPENSATION DIRECTLY FOR THE PROVISION OF INVESTMENT ADVICE (AS OPPOSED TO OTHER SERVICES) IN CONNECTION WITH THE ERISA PLAN’S ACQUISITION OR ACCEPTANCE OF THIS CERTIFICATE.

CERTAIN TERMS USED IN THE FOREGOING PARAGRAPHS SHALL HAVE THE MEANINGS SPECIFIED IN THE AGREEMENT.



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

SPIRIT AIRLINES PASS THROUGH TRUST 2015-1C

SPIRIT AIRLINES PASS THROUGH CERTIFICATE, SERIES 2015-1C

Final Expected Regular Distribution Date: April 1, 2023

evidencing a fractional undivided interest in the Trust,

the property of which includes or will include, among

other things, certain Equipment Notes each secured by

an Aircraft owned by Spirit Airlines, Inc.



Certificate No. ______	$_________ Fractional Undivided Interest representing 0.00086779190350154% of the Trust per $1,000 face amount	PPN No. 84858@ AA3

THIS CERTIFIES THAT , for value received, is the registered owner of a $ ( dollars) Fractional Undivided Interest (or such lesser amounts as shall be the aggregate outstanding face amount hereof as set forth in the records of the Trustee) in the Spirit Airlines Pass Through Trust, Series 2015-1C (the “Trust”) created by WILMINGTON TRUST, NATIONAL ASSOCIATION, as trustee (together with any successor in interest and any successor or other trustee appointed pursuant to the Trust Supplement referred to below, the “Trustee”) under a Pass Through Trust Agreement, dated as of August 11, 2015 (the “Basic Agreement”), between Wilmington Trust, National Association and Spirit Airlines, Inc., a Delaware corporation (together with any successor in interest pursuant to Section 5.02 of the Basic Agreement, the “Company”), as supplemented by Trust Supplement No. 2015-1C thereto dated as of May 10, 2018 (collectively with the Basic Agreement, and as may be amended from time to time, the “Agreement”), between the Trustee and the Company, a summary of certain of the pertinent provisions of which is set forth below. To the extent not otherwise defined herein, the capitalized terms used herein have the meanings assigned to them in the Agreement. This Certificate is one of the duly authorized Certificates designated as “Spirit Airlines Pass Through Certificates, Series 2015-1C” (herein called the “Certificates”). This Certificate is issued under and is subject to the terms, provisions and conditions of the Agreement. By virtue of its acceptance hereof, the Certificateholder of this Certificate assents to and agrees to be bound by all of the provisions of the Agreement and the Intercreditor Agreement, including the subordination provisions of Section 9.09 of the Intercreditor Agreement. The Trust Property is expected to include certain Equipment Notes and includes all rights of the Trust and the Trustee, on behalf of the Trust, to receive any payments under the Intercreditor Agreement. Each issue of the Equipment Notes will be secured by, among other things, a security interest in the Aircraft owned by the Company.

The Certificates represent Fractional Undivided Interests in the Trust and the Trust Property, and will have no rights, benefits or interest in respect of any other separate trust established pursuant to the terms of the Basic Agreement for any other series of certificates issued pursuant thereto.

Subject to and in accordance with the terms of the Agreement and the Intercreditor Agreement, from funds then available to the Trustee, there will be distributed on each April 1 and October 1 (each, a “Regular Distribution Date”), commencing on October 1, 2018, to the Person in whose name this



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Certificate is registered at the close of business on the 15th day preceding the Regular Distribution Date, an amount in respect of the Scheduled Payments on the Series C Equipment Notes due on such Regular Distribution Date, the receipt of which has been confirmed by the Trustee, equal to the product of the percentage interest in the Trust evidenced by this Certificate and an amount equal to the sum of such Scheduled Payments. Subject to and in accordance with the terms of the Agreement and the Intercreditor Agreement, in the event that Special Payments on the Series C Equipment Notes are received by the Trustee, from funds then available to the Trustee, there shall be distributed on the applicable Special Distribution Date, to the Person in whose name this Certificate is registered at the close of business on the 15th day preceding the applicable Special Distribution Date, an amount in respect of such Special Payments on the Series C Equipment Notes, the receipt of which has been confirmed by the Trustee, equal to the product of the percentage interest in the Trust evidenced by this Certificate and an amount equal to the sum of such Special Payments so received. If a Regular Distribution Date or Special Distribution Date is not a Business Day, distribution shall be made on the immediately following Business Day and no interest shall accrue during the intervening period. The Trustee shall mail notice of each Special Payment and the Special Distribution Date therefor to the Certificateholder of this Certificate.

Distributions on this Certificate will be made by the Trustee by check mailed to the Person entitled thereto, without the presentation or surrender of this Certificate or the making of any notation hereon, provided that to the extent the Certificateholder of this Certificate has provided in writing sufficient wire transfer details to the Trustee, each such distribution shall be made by wire transfer in immediately available funds to the account designated by the Certificateholder of this Certificate. Except as otherwise provided in the Agreement and notwithstanding the above, the final distribution on this Certificate will be made after notice mailed by the Trustee of the pendency of such distribution and only upon presentation and surrender of this Certificate at the office or agency of the Trustee specified in such notice.

The Certificates do not represent a direct obligation of, or an obligation guaranteed by, or an interest in, the Company, the Trustee, the Subordination Agent, any Loan Trustee or any Affiliate of any thereof. The Certificates are limited in right of payment, all as more specifically set forth on the face hereof and in the Agreement. All payments or distributions made to Certificateholders under the Agreement shall be made only from the Trust Property and only to the extent that the Trustee shall have sufficient income or proceeds from the Trust Property to make such payments in accordance with the terms of the Agreement. Each Certificateholder of this Certificate, by its acceptance hereof, agrees that it will look solely to the income and proceeds from the Trust Property to the extent available for any payment or distribution to such Certificateholder pursuant to the terms of the Agreement and that it will not have any recourse to the Company, the Trustee, the Loan Trustees or any Affiliate of any thereof except as otherwise expressly provided in the Agreement, in any Note Document or in the Intercreditor Agreement. This Certificate does not purport to summarize the Agreement and reference is made to the Agreement for information with respect to the interests, rights, benefits, obligations, proceeds and duties evidenced hereby. A copy of the Agreement may be examined during normal business hours at the principal office of the Trustee, and at such other places, if any, designated by the Trustee, by any Certificateholder upon request.



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

holding Certificates evidencing Fractional Undivided Interests aggregating not less than a majority in interest in the Trust. Any such consent by the Certificateholder of this Certificate shall be conclusive and binding on such Certificateholder and upon all future Certificateholders of this Certificate and of any Certificate issued upon the transfer hereof or in exchange hereof or in lieu hereof whether or not notation of such consent is made upon this Certificate. The Agreement also permits the amendment thereof, in certain limited circumstances, without the consent of the Certificateholders of any of the Certificates.

As provided in the Agreement and subject to certain limitations set forth therein, the transfer of this Certificate is registrable in the Register upon surrender of this Certificate for registration of transfer at the offices or agencies maintained by the Trustee in its capacity as Registrar, or by any successor Registrar, duly endorsed or accompanied by a written instrument of transfer in form satisfactory to the Trustee and the Registrar, duly executed by the Certificateholder hereof or such Certificateholder’s attorney duly authorized in writing, and thereupon one or more new Certificates of authorized denominations evidencing the same aggregate Fractional Undivided Interest in the Trust will be issued to the designated transferee or transferees.

The Certificates are issuable only as registered Certificates without coupons in minimum denominations of $500,000 Fractional Undivided Interest and integral multiples of $1,000 in excess thereof except that one Certificate may be issued in a different denomination. As provided in the Agreement and subject to certain limitations therein set forth, the Certificates are exchangeable for new Certificates of authorized denominations evidencing the same aggregate Fractional Undivided Interest in the Trust, as requested by the Certificateholder surrendering the same.

No service charge will be made for any such registration of transfer or exchange, but the Trustee shall require payment of a sum sufficient to cover any tax or governmental charge payable in connection therewith.

The Company, the Trustee, the Registrar and any Paying Agent shall deem and treat the Person in whose name this Certificate is registered as the owner hereof for all purposes, and none of the Company, the Trustee, the Registrar or any such agent shall be affected by any notice to the contrary.

Each Certificateholder, by its acceptance of this Certificate or such interest, agrees to treat the Trust as a grantor trust for all U.S. federal, state and local income tax purposes.

The obligations and responsibilities created by the Agreement and the Trust created thereby shall terminate upon the distribution to Certificateholders of all amounts required to be distributed to them pursuant to the Agreement and the disposition of all property held as part of the Trust Property.

Any Person acquiring or accepting this Certificate will, by such acquisition or acceptance, be deemed to (a) represent and warrant to the Company, the Loan Trustees and the Trustee that either: (i) no assets of a Plan or any trust established with respect to a Plan have been used to purchase or hold this Certificate or (ii) the purchase and holding of this Certificate by such Person are exempt from the prohibited transaction restrictions of ERISA and the Code or provisions of Similar Law pursuant to one or more prohibited transaction statutory or administrative exemptions or similar exemptions under Similar Law and (b) direct the Trustee to invest the assets held in the Trust pursuant to, and take all other actions contemplated



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

by, the terms and conditions of the Basic Agreement, this Trust Supplement, the Intercreditor Agreement, the Deposit Agreement, the Escrow Agreement, the NPA, and each Participation Agreement.

Any Person who is an ERISA Plan and is acquiring or accepting this Certificate will, by such acquisition or acceptance, be deemed to represent and warrant to the Company, the Loan Trustees and the Trustee, at any time when regulation 29 C.F.R. Section 2510.3-21, as modified in 2016, is applicable that the decision to acquire or accept this Certificate has been made by a duly authorized fiduciary of the ERISA Plan that (i) is independent (as that term is used in 29 C.F.R. 2510.3-21(c)(1)) of the Company and its Affiliates and there is no financial interest, ownership interest, or other relationship, agreement or understanding or otherwise that would limit its ability to carry out its fiduciary responsibility to the ERISA Plan; (ii) is a bank, insurance carrier, registered investment adviser, a registered broker-dealer, or an independent fiduciary that holds, or has under management or control, total assets of at least $50 million (in each case, as specified in 29 C.F.R. 2510.3-21(c)(1)(i)(A)-(E)); (iii) is capable of evaluating investment risks independently, both in general and with regard to particular transactions and investment strategies (including, without limitation, with respect to the decision to acquire or accept this Certificate); (iv) has been fairly informed that the Company and its Affiliates have not and will not undertake to provide impartial investment advice, or to give advice in a fiduciary capacity, in connection with the acquisition or acceptance of this Certificate; ( v ) has been fairly informed that the Company and its Affiliates have financial interests in the ERISA Plan’s acquisition or acceptance of this Certificate, which interests may conflict with the interest of the ERISA Plan, as more fully described in the offering materials; ( vi ) is a fiduciary under ERISA or the Code, or both, with respect to the decision to acquire or accept this Certificate and is responsible for exercising (and has exercised) independent judgment in evaluating whether to invest the assets of the ERISA Plan in this Certificate; and ( vii ) is not paying the Company or any of its Affiliates, any fee or other compensation directly for the provision of investment advice (as opposed to other services) in connection with the ERISA Plan’s acquisition or acceptance of this Certificate.

THIS CERTIFICATE AND THE AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

Unless the certificate of authentication hereon has been executed by the Trustee, by manual signature, this Certificate shall not be entitled to any benefit under the Agreement or be valid for any purpose.



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

IN WITNESS WHEREOF, the Trustee has caused this Certificate to be duly executed.

SPIRIT AIRLINES PASS THROUGH TRUST
2015-1C


By:	WILMINGTON TRUST, NATIONAL ASSOCIATION, as Trustee


By:	_____________________________

Title:

Dated:



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

TRUSTEE’S CERTIFICATE OF AUTHENTICATION

This is one of the Certificates referred to in the within-mentioned Agreement.

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Trustee


By:	_______________________________

Authorized Officer



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

[FORM OF TRANSFER NOTICE]

FOR VALUE RECEIVED the undersigned registered holder hereby sell(s), assign(s) and transfer(s) unto

Insert Taxpayer Identification No.

___________________________

Please print or typewrite name and address including zip code of assignee

___________________________

the within Certificate and all rights thereunder, hereby irrevocably constituting and appointing ___________________________ attorney to transfer said Certificate on the books of the Trustee with full power of substitution in the premises.



Date: _____________	_______________________________ NOTICE: The signature to this assignment must correspond with the name as written upon the face of the within-mentioned instrument in every particular, without alteration or any change whatsoever.


	SIGNATURE GUARANTEE: _______________

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

EXHIBIT B to
TRUST SUPPLEMENT NO. 2015-1C

AMENDMENTS TO BASIC AGREEMENT

Part A

Section 5.02. Consolidation, Merger, Etc . The Company shall not consolidate with or merge into any other Person or convey, transfer or lease substantially all of its assets as an entirety to any Person, unless:

(i) the successor or transferee entity shall, if and to the extent required under Section 1110 in order that any Loan Trustee continues to be entitled to any benefits of Section 1110 with respect to any Aircraft, be a holder of an air carrier operating certificate issued by the Secretary of Transportation pursuant to Chapter 447 of Title 49 of the United States Code for aircraft capable of carrying ten or more individuals or 6,000 pounds or more of cargo, and shall execute and deliver to the Trustee an agreement containing the express assumption by such successor or transferee entity of the due and punctual performance and observance of each covenant and condition of the Note Documents, the NPA and this Agreement to be performed or observed by the Company; and

(ii) the Company shall deliver to the Trustee a certificate signed by a Responsible Officer of the Company stating that such consolidation, merger, conveyance, transfer or lease and the assumption agreement mentioned in clause (i) above comply with this Section 5.02.

Upon any consolidation or merger, or any conveyance, transfer or lease of substantially all of the assets of the Company as an entirety in accordance with this Section 5.02, the successor Person formed by such consolidation or into which the Company is merged or to which such conveyance, transfer or lease is made shall succeed to, and be substituted for, and may exercise every right and power of, the Company under the Note Documents, the NPA and this Agreement with the same effect as if such successor Person had been named as the Company herein.

Part B

Section 6.07. Certificateholders May Not Bring Suit Except Under Certain Conditions . A Certificateholder of any series shall not have the right to institute any suit, action or proceeding at law or in equity or otherwise with respect to this Agreement, the related Trust Supplement or the Certificates or otherwise, or for the appointment of a receiver or for the enforcement of any other remedy under this Agreement, the related Trust Supplement or the Certificates or otherwise, unless:


(1)	such Certificateholder previously shall have given written notice to the Trustee of a continuing Event of Default;



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2


(2)	Certificateholders holding Certificates of such series evidencing Fractional Undivided Interests aggregating not less than 25% of the related Trust shall have requested the Trustee in writing to institute such action, suit or proceeding and shall have offered to the Trustee indemnity as provided in Section 7.03(e);


(3)	the Trustee shall have refused or neglected to institute any such action, suit or proceeding for 60 days after receipt of such notice, request and offer of indemnity; and


(4)	no Direction inconsistent with such written request shall have been given to the Trustee during such 60-day period by either Certificateholders holding Certificates of such series evidencing Fractional Undivided Interests aggregating not less than a majority in interest in the related Trust or the Controlling Party under the related Intercreditor Agreement.

Except to the extent provided in any applicable Intercreditor Agreement or in any applicable Trust Supplement, it is understood and intended that no one or more of the Certificateholders of any series shall have any right in any manner whatsoever hereunder or under the related Trust Supplement or under the Certificates of such series to (i) surrender, impair, waive, affect, disturb or prejudice any property in the Trust Property of the related Trust, or the lien of any related Indenture on any property subject thereto, or the rights of the Certificateholders of such series or the holders of the related Equipment Notes, (ii) obtain or seek to obtain priority over or preference with respect to any other such Certificateholder of such series or (iii) enforce any right under this Agreement, the related Trust Supplement or under the Certificates of such series, except in the manner provided in this Agreement and for the equal, ratable and common benefit of all the Certificateholders of such series.

Part C

Provided that there is a bank or trust company in a U.S. jurisdiction where there are no Avoidable Taxes that is willing to act as Trustee and is eligible to act as Trustee under Section 7.08 and the applicable provisions of any Trust Supplement, the Company shall promptly appoint a successor Trustee of such Trust in a jurisdiction where there are no Avoidable Taxes.

Part D

(a) file with the Trustee, within 30 days after the Company files the same with the SEC, copies of the annual reports and of the information, documents and other reports (or copies of such portions of any of the foregoing as the SEC may from time to time by rules and regulations prescribe) which the Company is required to file with the SEC pursuant to Section 13 or Section 15(d) of the Securities Exchange Act of 1934, as amended; or, if the Company is not required to file information, documents or reports pursuant to either of such sections, then to file with the Trustee and the SEC, in accordance with rules and regulations prescribed by the SEC, such supplementary and periodic information, documents and reports which may be required pursuant to Section 13 of the Securities



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

Exchange Act of 1934, as amended, in respect of a security listed and registered on a national securities exchange as may be prescribed in such rules and regulations;

Part E

(4) (A) to cure any ambiguity or to correct any mistake or inconsistency contained in this Basic Agreement or in any related Trust Supplement, any Intercreditor Agreement or any Liquidity Facility; or (B) to make or modify any other provision in regard to matters or questions arising under this Basic Agreement or any related Trust Supplement, any Intercreditor Agreement or any Liquidity Facility as the Company may deem necessary or desirable and that will not materially adversely affect the interests of the related Certificateholders; or (C) to correct or supplement the description of any property constituting property of any Trust or the description of any Aircraft, and to reflect the substitution of another aircraft for any Aircraft; or

Part F

Section 12.01. Limitation on Rights of Certificateholders . (a) The insolvency, death or incapacity of any Certificateholder of any series shall not operate to terminate this Agreement or the related Trust, nor entitle such Certificateholder’s legal representative or heirs to claim an accounting or to take any action or commence any proceeding in any court for a partition or winding up of the Trust, nor otherwise affect the rights, obligations and liabilities of the parties hereto or any of them. No Certificateholder of any series shall be entitled to revoke the related Trust.

(b) No transfer, by operation of law or otherwise, of any Certificate or other right, title and interest of any Certificateholder in and to the applicable Trust Property or under the related Trust shall operate to terminate the Trust or entitle such Certificateholder or any successor or transferee of such Certificateholder to an accounting or to the transfer to it of legal title to any part of such Trust Property.

Part G

Section 12.02. Liabilities of Certificateholders . The Certificateholders of each series shall not be personally liable for obligations of the related Trust, the Fractional Undivided Interests represented by the Certificates of such series shall be nonassessable for any losses or expenses of such Trust or for any reason whatsoever, and the Certificates of such series upon authentication thereof by the Trustee pursuant to Section 3.02 are and shall be deemed fully paid. No Certificateholder of such series shall have any right (except as expressly provided herein) to vote or in any manner otherwise control the operation and management of the related Trust Property, the related Trust, or the obligations of the parties hereto, nor shall anything set forth herein, or contained in the terms of the Certificates of such series, be construed so as to constitute the Certificateholders of such series from time to time as partners or members of an association.



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

SCHEDULE I to
TRUST SUPPLEMENT NO. 2015-1C

SERIES C EQUIPMENT NOTES,

PRINCIPAL AMOUNTS, MATURITIES AND AIRCRAFT



Initial Principal Amount of Series C Equipment Notes	Maturity	Aircraft	Manufacturer Serial Number
$5,965,000.00	April 1, 2023	N644NK	7156
5,275,000.00	April 1, 2023	N645NK	7008
5,366,000.00	April 1, 2023	N646NK	7062
6,995,000.00	April 1, 2023	N660NK	6804
7,168,000.00	April 1, 2023	N661NK	6867
7,467,000.00	April 1, 2023	N662NK	6897
7,596,000.00	April 1, 2023	N663NK	6994
8,261,000.00	April 1, 2023	N664NK	7021
7,822,000.00	April 1, 2023	N665NK	7045
8,159,000.00	April 1, 2023	N667NK	7058
8,427,000.00	April 1, 2023	N668NK	7135
8,764,000.00	April 1, 2023	N669NK	7296
8,831,000.00	April 1, 2023	N670NK	7106
9,221,000.00	April 1, 2023	N671NK	7246
9,918,000.00	April 1, 2023	N672NK	7522



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.2

SCHEDULE II to
TRUST SUPPLEMENT NO. 2015-1C

NOTE DOCUMENTS

Participation Agreement
Indenture
Manufacturer’s Consent (as defined in any applicable Indenture)

For each of the aircraft listed in Schedule I.



		Trust Supplement No. 2015-1C (Spirit 2015-1 EETC)

Exhibit 4.3

FINAL FORM

FIRST AMENDMENT TO PARTICIPATION AGREEMENT

([Reg. No.])

Dated as of [●], 2018

among

SPIRIT AIRLINES, INC.,

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Pass Through Trustee under each of the
Pass Through Trust Agreements,

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Subordination Agent,

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Loan Trustee,

and

WILMINGTON TRUST, NATIONAL ASSOCIATION,
in its individual capacity as set forth herein

One Airbus [Model]
(Generic Manufacturer and Model Airbus [Generic Model]) Aircraft
U.S. Registration No. [Reg. No.]

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

ARTICLE 1

DEFINITIONS; AMENDMENTS

Section 1.01. Definitions...............................................................................................3

Section 1.02. Other Definitional Provisions.................................................................4

Section 1.03. Amendments to Original Participation Agreement.................................5

Section 1.04. Supplemental Provisions........................................................................11

ARTICLE 2

THE LOANS

Section 2.01. The Loans...............................................................................................11

Section 2.02. Issuance of Series C Equipment Notes..................................................11

Section 2.03. The Series C Closing.............................................................................12

ARTICLE 3

CONDITIONS PRECEDENT

Section 3.01. Conditions Precedent to Obligations of the Pass Through Trustees......12

Section 3.02. Conditions Precedent to Obligations of the Company...........................16

ARTICLE 4

REPRESENTATIONS AND WARRANTIES OF THE COMPANY

Section 4.01. Representations and Warranties of the Company.................................18

ARTICLE 5

REPRESENTATIONS, WARRANTIES AND COVENANTS
OF WTNA

Section 5.01. Representations, Warranties and Covenants of WTNA.........................20

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

ARTICLE 6

FEES AND EXPENSES

Section 6.01. Fees and Expenses.................................................................................24

ARTICLE 7

MISCELLANEOUS

Section 7.01. Effective Time........................................................................................24

Section 7.02. Ratification and Agreements; Direction.................................................24

Section 7.03. Governing Law.......................................................................................25

Section 7.04. Severability............................................................................................25

Section 7.05. No Oral Modifications or Continuing Waivers; Consents.....................25

Section 7.06. Effect of Headings and Table of Contents.............................................25

Section 7.07. Successors and Assigns..........................................................................25

Section 7.08. Benefits of Agreement...........................................................................26

Section 7.09. Counterparts...........................................................................................26

Section 7.10. Submission to Jurisdiction.....................................................................26


Schedule I	- Amended Schedule I: Equipment Notes, Purchasers and Original Principal Amounts


Schedule II	- Amended Schedule II: Trust Supplements


Exhibit A	- Form of First Indenture Amendment


Exhibit B-1	- Form of Opinion of Counsel for the Company


Exhibit B-2	- Form of Opinion of Debevoise & Plimpton LLP, special counsel for the Company


Exhibit C	- Form of Opinion of Special Counsel for the Loan Trustee, the Pass Through Trustees, the Subordination Agent and WTNA


Exhibit D	- Form of Opinion of Special FAA Counsel

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

FIRST AMENDMENT TO PARTICIPATION AGREEMENT

([REG. NO.])

This FIRST AMENDMENT TO PARTICIPATION AGREEMENT ([REG. NO.]), dated as of [●], 2018 (this “ Amendment ”), is made by and among SPIRIT AIRLINES, INC., a Delaware corporation (together with its successors and permitted assigns, the “ Company ”), WILMINGTON TRUST, NATIONAL ASSOCIATION, a national banking association (in its individual capacity, together with its successors and permitted assigns, “ WTNA ”), not in its individual capacity except as otherwise expressly provided in any of the Operative Documents or the Pass Through Documents, but solely as Pass Through Trustee under each of the Pass Through Trust Agreements (such terms and other capitalized terms used herein without definition being defined as provided in Section 1.01), WILMINGTON TRUST, NATIONAL ASSOCIATION, a national banking association, as subordination agent and trustee (in such capacity, together with any successor trustee in such capacity, the “ Subordination Agent ”) under the Intercreditor Agreement, and WILMINGTON TRUST, NATIONAL ASSOCIATION, as loan trustee (in such capacity, together with any successor trustee in such capacity, the “ Loan Trustee ”) under the Indenture.

WITNESSETH:

WHEREAS, on the Closing Date, which occurred on [INSERT DATE OF PARTICIPATION AGREEMENT], the parties hereto (other than the Class C Trustee) entered into that certain Participation Agreement ([Reg. No.]), dated as of [INSERT DATE OF PARTICIPATION AGREEMENT] (the “ Original Participation Agreement ”) in order to provide for the financing of the Aircraft described therein;

WHEREAS, in connection with the Original Participation Agreement, the Company and the Loan Trustee entered into that certain Indenture and Security Agreement ([Reg. No.]), dated as of [INSERT DATE OF PARTICIPATION AGREEMENT], as supplemented by Indenture Supplement No. 1 thereto, dated [INSERT DATE OF PARTICIPATION AGREEMENT] (the “ Original Indenture ”), pursuant to which, among other things, the Company issued to the Subordination Agent the Series A Equipment Notes and the Series B Equipment Notes, in each case in the applicable original principal amount, having the applicable maturity and bearing interest at the applicable Debt Rate as specified on Schedule I to the Original Indenture, which Equipment Notes are secured by a security interest in all right, title and interest of the Company in and to the Aircraft and certain other property described in the Original Indenture (as further described in the Original Indenture, the “ Collateral ”);

WHEREAS, pursuant to the Basic Pass Through Trust Agreement and the Class A Trust Supplement, the Class A Pass Through Trust was created on August 11, 2015 to

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

facilitate the financing of certain aircraft owned by the Company, including the Aircraft, and the Class A Certificates were issued and sold on August 11, 2015;

WHEREAS, pursuant to the Basic Pass Through Trust Agreement and the Class B Trust Supplement, the Class B Pass Through Trust was created on August 11, 2015 to facilitate the financing of certain aircraft owned by the Company, including the Aircraft, and the Class B Certificates were issued and sold on August 11, 2015;

WHEREAS, Section 2.02 of the Original Participation Agreement provides that, subject to Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior to the Series C Closing) and Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing), the Company shall have the option to issue one or more Series of Additional Series Equipment Notes from time to time after the Closing Date;

WHEREAS, Section 2.02 of the Original Indenture provides that, subject to compliance with the conditions set forth in Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior to the Series C Closing), Section 2.02 of the Original Participation Agreement and Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing), the Company shall have the option to issue one or more Series of Additional Series Equipment Notes from time to time after the Closing Date;

WHEREAS, the Company now desires to issue an Additional Series Equipment Notes to be designated as “Series C Equipment Notes” (such Additional Series Equipment Notes, the “ Series C Equipment Notes ”), which Series C Equipment Notes are to be secured by a security interest in all right, title and interest of the Company in and to the Aircraft and the other Collateral;

WHEREAS, concurrently with the execution and delivery of this Amendment, the Company and the Loan Trustee are entering into the First Indenture Amendment, pursuant to which, among other things, the Company will issue Series C Equipment Notes under the Indenture;

WHEREAS, pursuant to the Basic Pass Through Trust Agreement and the Class C Trust Supplement, the Class C Pass Through Trust has been created to facilitate certain of the transactions contemplated by this Amendment, including, without limitation, the issuance and sale of the Class C Certificates; and

WHEREAS, pursuant to the Intercreditor Agreement, the Subordination Agent holds the Series A Equipment Notes on behalf of the Class A Pass Through Trust, holds the Series

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B Equipment Notes on behalf of the Class B Pass Through Trust and will hold, when issued, the Series C Equipment Notes on behalf of the Class C Pass Through Trust;

NOW, THEREFORE, in consideration of the foregoing premises and the mutual agreements herein contained, and of other good and valuable consideration the receipt and adequacy of which are hereby acknowledged, the parties hereto agree as follows:

ARTICLE I

DEFINITIONS; AMENDMENTS

Section 1.01. Definitions . Except as otherwise defined herein, capitalized terms in this Amendment have the meanings assigned to them in the Original Participation Agreement. For the purposes of this Amendment, the following capitalized terms shall have the following meanings:

“ Class A Trust Supplement ” means the Trust Supplement No. 2015-1A, dated as of August 11, 2015, between the Company and WTNA, as Class A Trustee.

“ Class B Trust Supplement ” means the Trust Supplement No. 2015-1B, dated as of August 11, 2015, between the Company and WTNA, as Class B Trustee.

“ Class C Certificates ” means pass through certificates issued by the Class C Pass Through Trust.

“ Class C Pass Through Trust ” means the Spirit Airlines Pass Through Trust 2015-1C created pursuant to the Basic Pass Through Trust Agreement, as supplemented by the Class C Trust Supplement.

“ Class C Trustee ” means the trustee for the Class C Pass Through Trust.

“ Class C Trust Supplement ” means the Trust Supplement No. 2015-1C, dated as of the Series C Closing Date, between the Company and WTNA, as Class C Trustee.

“ Collateral ” has the meaning set forth in the second recital hereto.

“ First Indenture Amendment ” means an amendment to the Original Indenture, substantially in the form attached hereto as Exhibit A .

“ Original Indenture ” has the meaning set forth in the second recital hereto.

“ Original Participation Agreement ” has the meaning set forth in the first recital hereto.

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“ Pass Through Certificates ” means the Class A Certificates, the Class B Certificates and the Class C Certificates.

“ Pass Through Trust Agreement ” means each of the Class A Trust Supplement, the Class B Trust Supplement and the Class C Trust Supplement, together in each case with the Basic Pass Through Trust Agreement, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Pass Through Trustee ” means each of the Class A Trustee, the Class B Trustee and the Class C Trustee.

“ Series C Closing ” has the meaning set forth in Section 2.03.

“ Series C Closing Date ” means [●], 2018 or such other time as the parties shall agree.

“ Series C Equipment Notes ” has the meaning set forth in the seventh recital hereto.

“ Trust Supplement ” means each of the Class A Trust Supplement, the Class B Trust Supplement and the Class C Trust Supplement.

Section 1.02. Other Definitional Provisions .

(a) For purposes of this Amendment, (i) the term “Participation Agreement” means the Original Participation Agreement as amended by this Amendment and (ii) the term “Indenture” means the Original Indenture as amended by the First Indenture Amendment.

(b) All references in this Amendment to designated “Articles”, “Sections”, “Subsections”, “Schedules”, “Exhibits”, “Annexes” and other subdivisions are to the designated Article, Section, Subsection, Schedule, Exhibit, Annex or other subdivision of this Amendment, unless otherwise specifically stated.

(c) The words “herein”, “hereof” and “hereunder” and other words of similar import refer to this Amendment as a whole and not to any particular Article, Section, Subsection, Schedule, Exhibit, Annex or other subdivision.

(d) All references in this Amendment to a “government” are to such government and any instrumentality or agency thereof.

(e) Unless the context otherwise requires, whenever the words “including”, “include” or “includes” are used herein, they shall be deemed to be followed by the phrase “without limitation”.

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(f) All references in this Amendment to a Person shall include successors and permitted assigns of such Person.

Section 1.03. Amendments to Original Participation Agreement . The Original Participation Agreement is hereby amended as follows:

(a) Amendment to Section 2.02 . Section 2.02 of the Original Participation Agreement is amended by deleting it in its entirety and replacing it with the following:

Section 2.02. Issuance of Equipment Notes . Upon the occurrence of the above payments by the Pass Through Trustee for each Pass Through Trust to the Company, the Company shall issue, pursuant to and in accordance with Article II of the Indenture, to the Subordination Agent as agent and trustee for the Pass Through Trustee for each Pass Through Trust, one or more Equipment Notes of the maturity and aggregate original principal amount and bearing the interest rate set forth in Schedule I opposite the name of such Pass Through Trust. Each such Equipment Note shall be duly authenticated by the Loan Trustee pursuant to the Indenture, registered in the name of the Subordination Agent and dated the date of original issuance thereof and shall be delivered by the Loan Trustee to the Subordination Agent. In addition, subject to Section 4(a)(v) of the Note Purchase Agreement and Section 8.01(c) or 8.01(d) of the Intercreditor Agreement, as applicable, the Company shall have the option after the Class C Issuance Date, from time to time, (i) to redeem all but not less than all of the Series B Equipment Notes or all but not less than all of the Series C Equipment Notes (or all but not less than all of any Series of Additional Series Equipment Notes) and to issue under the Indenture new Equipment Notes with the same Series designation as, but with terms that may be the same as or different from those of, the redeemed Equipment Notes, (ii) to issue one or more Series of Additional Series Equipment Notes under the Indenture and (iii) following the payment in full of all but not less than all of the Series B Equipment Notes or all but not less than all of the Series C Equipment Notes (or all but not less than all of any Series of Additional Series Equipment Notes), to issue under the Indenture new Equipment Notes with the same Series designation as, but with terms that may be the same as or different from those of, such Equipment Notes that have been paid in full. If new Series B Equipment Notes, new Series C Equipment Notes or Additional Series Equipment Notes or new Additional Series Equipment Notes are so issued after the Class C Issuance Date, each Noteholder of such Equipment Notes shall be deemed to be a party hereto without further act, and shall be entitled to execute, and at the request of the Company shall execute, a counterpart to this Agreement. For the avoidance of doubt, if the Company shall issue new “Series B Equipment Notes”, new “Series C Equipment Notes” or “Additional Series Equipment Notes” of any Series or new “Additional Series Equipment Notes”, in each case under any Related Indenture, the Company may, but shall not be required

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to, issue, as the case may be, new Series B Equipment Notes, new Series C Equipment Notes or Additional Series Equipment Notes of the same Series or new Additional Series Equipment Notes of the same Series, in each case under the Indenture.

(b) Amendment to Section 6.01(g) . Section 6.01(g) of the Original Participation Agreement is amended by deleting it in its entirety and replacing it with the following:

(g) No Petition . Each of the Company, the Loan Trustee, each Pass Through Trustee, the Subordination Agent and any other Noteholder covenants that (i) until one year and one day after the Series A Equipment Notes have been paid in full, it shall not acquiesce, petition or otherwise invoke or cause or join in invoking or causing the Class A Pass Through Trust or any other Person to invoke the process of any governmental authority for the purpose of commencing or sustaining a case (whether voluntary or not) against the Class A Pass Through Trust under any bankruptcy, insolvency or similar law or appointing a receiver, liquidator, assignee, trustee, custodian, sequestrator or other similar official of the Class A Pass Through Trust or any substantial part of its property or ordering the winding-up or liquidation of the affairs of the Class A Pass Through Trust, (ii) until one year and one day after the Series B Equipment Notes have been paid in full, it shall not acquiesce, petition or otherwise invoke or cause or join in invoking or causing the Class B Pass Through Trust or any other Person to invoke the process of any governmental authority for the purpose of commencing or sustaining a case (whether voluntary or not) against the Class B Pass Through Trust under any bankruptcy, insolvency or similar law or appointing a receiver, liquidator, assignee, trustee, custodian, sequestrator or other similar official of the Class B Pass Through Trust or any substantial part of its property or ordering the winding-up or liquidation of the affairs of the Class B Pass Through Trust, (iii) until one year and one day after the Series C Equipment Notes have been paid in full, it shall not acquiesce, petition or otherwise invoke or cause or join in invoking or causing the Class C Pass Through Trust or any other Person to invoke the process of any governmental authority for the purpose of commencing or sustaining a case (whether voluntary or not) against the Class C Pass Through Trust under any bankruptcy, insolvency or similar law or appointing a receiver, liquidator, assignee, trustee, custodian, sequestrator or other similar official of the Class C Pass Through Trust or any substantial part of its property or ordering the winding-up or liquidation of the affairs of the Class C Pass Through Trust, and (iv) if any Additional Series Equipment Notes of any Series shall have been issued, until one year and one day after such Additional Series Equipment Notes have been paid in full, it shall not acquiesce, petition or otherwise invoke or cause or join in invoking or causing the related Additional Series Pass Through Trust or any other Person to invoke the process of any governmental authority for the purpose of commencing or sustaining a case (whether voluntary or not) against such Additional Series Pass Through Trust

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under any bankruptcy, insolvency or similar law or appointing a receiver, liquidator, assignee, trustee, custodian, sequestrator or other similar official of such Additional Series Pass Through Trust or any substantial part of its property or ordering the winding-up or liquidation of the affairs of such Additional Series Pass Through Trust.

(c) Amendment to Schedule I . Schedule I to the Original Participation Agreement is amended by deleting it in its entirety and replacing it with Schedule I hereto (it being agreed and understood that no amendments are being made to the maturity, original principal amount or interest rate of the Series A Equipment Notes or the Series B Equipment Notes).

(d) Amendment to Schedule II . Schedule II to the Original Participation Agreement is amended by deleting it in its entirety and replacing it with Schedule II hereto.

(e) Amendment to Annex A . Annex A to the Original Participation Agreement is amended as follows:

(i) The definition of “ Additional Series ” or “ Additional Series Equipment Notes ” is deleted in its entirety and replaced with the following:

“ Additional Series ” or “ Additional Series Equipment Notes ” means Equipment Notes issued under the Indenture and designated as a Series (other than “Series A”, “Series B” or “Series C”) thereunder in the principal amounts and maturities and bearing interest as specified in Schedule I to the Indenture amended at the time of original issuance of such Additional Series under the heading for such Series.

(ii) The definition of “ Class A Pass Through Trust ” is deleted in its entirety and replaced with the following:

“ Class A Pass Through Trust ” means the Spirit Airlines Pass Through Trust 2015-1A created pursuant to the Basic Pass Through Trust Agreement, as supplemented by Trust Supplement No. 2015-1A, dated as of the Original Issuance Date, between the Company and WTNA, as Class A Trustee.

(iii) The definition of “ Class B Pass Through Trust ” is deleted in its entirety and replaced with the following:

“ Class B Pass Through Trust ” means the Spirit Airlines Pass Through Trust 2015-1B created pursuant to the Basic Pass Through Trust Agreement, as supplemented by Trust Supplement No. 2015-1B, dated as of the Original Issuance Date, between the Company and WTNA, as Class B Trustee.

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(iv) The definition of “ Debt Rate ” is deleted in its entirety and replaced with the following:

“ Debt Rate ” means (i) with respect to any Series of Equipment Notes, the rate per annum specified for the applicable Series as such in Schedule I to the Indenture (as amended, in the case of any Additional Series, new Series B Equipment Notes, new Series C Equipment Notes or new Additional Series issued pursuant to Section 2.02 of the Indenture, at the time of issuance of such Series), and (ii) for any other purpose, with respect to any period, the weighted average interest rate per annum during such period borne by the outstanding Equipment Notes, excluding in each case any interest payable at the Past Due Rate.

(v) The definition of “ Deposit Agreement ” is deleted in its entirety and replaced with the following:

“ Deposit Agreement ” means, subject to Section 5(f) of the Note Purchase Agreement, each of the two Deposit Agreements, dated as of the Original Issuance Date, between the Escrow Agent and the Depositary, which relate to the Class A Pass Through Trust or the Class B Pass Through Trust, respectively; provided that, for purposes of any obligation of the Company, no amendment, modification or supplement to, or substitution or replacement of, any such Deposit Agreement shall be effective unless consented to by the Company.

(vi) The definition of “ Escrow Agreement ” is deleted in its entirety and replaced with the following:

“ Escrow Agreement ” means each of the two Escrow and Paying Agent Agreements, dated as of the Original Issuance Date, among the Escrow Agent, the Paying Agent, the Underwriters and the applicable Pass Through Trustee, which relate to the Class A Pass Through Trust or the Class B Pass Through Trust, respectively; provided that, for purposes of any obligation of the Company, no amendment, modification or supplement to, or substitution or replacement of, any such Escrow Agreement shall be effective unless consented to by the Company.

(vii) The definition of “ Intercreditor Agreement ” is deleted in its entirety and replaced with the following:

“ Intercreditor Agreement ” means that certain Amended and Restated Intercreditor Agreement (2015-1), dated as of the Class C Issuance Date,

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Exhibit 4.3

among the Pass Through Trustees, the Liquidity Providers and the Subordination Agent, as the same may be further amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligations of the Company, no amendment, modification or supplement to, or substitution or replacement of, such Intercreditor Agreement shall be effective unless consented to by the Company.

(viii) The definition of “ Issuance Date ” is deleted in its entirety.

(ix) The definition of “ Make-Whole Spread ” is deleted in its entirety and replaced with the following:

“ Make-Whole Spread ” means, with respect to any Series of Equipment Notes, the percentage specified for the applicable Series as such in Schedule I to the Indenture (as amended, in the case of any Additional Series, new Series B Equipment Notes, new Series C Equipment Notes or new Additional Series issued pursuant to Section 2.02 of the Indenture, at the time of issuance of such Series).

(x) The definition of “ Note Purchase Agreement ” is deleted in its entirety and replaced with the following:

“ Note Purchase Agreement ” means the Note Purchase Agreement, dated as of the Original Issuance Date, among the Company, the Subordination Agent, the Escrow Agent, the Paying Agent, and the Pass Through Trustees under each of the Pass Through Trust Agreements in effect as of the Original Issuance Date, providing for, among other things, the issuance and sale of certain equipment notes and to which the Class C Trustee shall have become a party by means of that certain Joinder to Note Purchase Agreement, dated as of the Class C Issuance Date, as the same may be further amended, supplemented or otherwise modified from time to time in accordance with its terms.

(xi) The definition of “ Pass Through Trust ” is deleted in its entirety and replaced with the following:

“ Pass Through Trust ” means each of the three separate grantor trusts that have been created pursuant to the Pass Through Trust Agreements to facilitate certain of the transactions contemplated by the Operative Documents.

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Exhibit 4.3

(xii) The definition of “ Pass Through Trust Agreement ” is deleted in its entirety and replaced with the following:

“ Pass Through Trust Agreement ” means each of the three separate Trust Supplements relating to the Pass Through Trusts, together in each case with the Basic Pass Through Trust Agreement, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

(xiii) The definition of “ Related Additional Series Equipment Notes ” is deleted in its entirety and replaced with the following:

“ Related Additional Series Equipment Note ” means, with respect to any particular Series of Additional Series Equipment Notes and as of any date, an “Additional Series Equipment Note”, as defined in each Related Indenture, having the same designation ( i.e. , “Series D”, “Series E” or the like) as such Series of Additional Series Equipment Notes, but only if as of such date it is held by the “Subordination Agent” under the “Intercreditor Agreement”, as such terms are defined in such Related Indenture.

(xiv) The definition of “ Series ” is deleted in its entirety and replaced with the following:

“ Series ” means any series of Equipment Notes, including the Series A Equipment Notes, the Series B Equipment Notes, the Series C Equipment Notes or, if issued, any Additional Series Equipment Notes.

(xv) The following definitions shall be added to Annex A to the Original Participation Agreement in alphabetical order:

“ Class C Certificates ” means Pass Through Certificates issued by the Class C Pass Through Trust.

“ Class C Issuance Date ” means [●], 2018.

“ Class C Pass Through Trust ” means the Spirit Airlines Pass Through Trust 2015-1C created pursuant to the Basic Pass Through Trust Agreement, as supplemented by Trust Supplement No. 2015-1C, dated as of the Class C Issuance Date, between the Company and WTNA, as Class C Trustee.

“ Class C Trustee ” means the trustee for the Class C Pass Through Trust.

“ Original Issuance Date ” means August 11, 2015.

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“ Related Series C Equipment Note ” means, as of any date, a “Series C Equipment Note”, as defined in each Related Indenture, but only if as of such date it is held by the “Subordination Agent” under the “Intercreditor Agreement”, as such terms are defined in such Related Indenture.

“ Series C ” or “ Series C Equipment Notes ” means Equipment Notes issued and designated as “Series C Equipment Notes” under the Indenture, in the original principal amount and maturities as specified in Schedule I to the Indenture under the heading “Series C Equipment Notes” and bearing interest at the Debt Rate for Series C Equipment Notes specified in Schedule I to the Indenture.

Section 1.04. Supplemental Provisions . For the avoidance of doubt, Articles II through VI of this Amendment are supplemental to, and not in replacement of, Articles II through VI of the Original Participation Agreement, which shall remain in full force and effect.

ARTICLE 2

THE LOANS

Section 2.01. The Loans . Subject to the terms and conditions of this Amendment and the Indenture, on the Series C Closing Date, the Class C Trustee shall make a loan to the Company by paying to the Company the aggregate original principal amounts of the Series C Equipment Notes being issued to the Class C Pass Through Trust as set forth on Schedule I hereto opposite the name of the Class C Pass Through Trust. The Class C Trustee, on behalf of the Class C Pass Through Trust, shall make its loan to the Company no later than 11:00 a.m. (New York City time) on the Series C Closing Date by transferring such amount in immediately available funds to the Company at its account at Wells Fargo Bank, N.A., 420 Montgomery, San Francisco, CA 94104, Account No. [], ABA Number [] (or to a designee of the Company as notified by the Company prior to the Series C Closing Date).

Section 2.02. Issuance of Series C Equipment Notes . Upon the occurrence of the above payment by the Class C Trustee to the Company, the Company shall issue, pursuant to and in accordance with Article II of the Indenture, to the Subordination Agent as agent and trustee for the Class C Trustee, one or more Series C Equipment Notes of the maturity and aggregate original principal amount and bearing the interest rate set forth in Schedule I hereto opposite the name of the Class C Pass Through Trust. Each such Series C Equipment Note shall be duly authenticated by the Loan Trustee pursuant to the Indenture, registered in the name of the Subordination Agent and dated the Series C Closing Date and shall be delivered by the Loan Trustee to the Subordination Agent.

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Exhibit 4.3

Each of the Pass Through Trustees and the Subordination Agent hereby authorizes and directs the Loan Trustee to execute and deliver this Amendment and the First Indenture Amendment and, subject to the terms hereof and thereof, to take the actions contemplated herein and therein.

Section 2.03. The Series C Closing . The closing (the “ Series C Closing ”) of the transactions contemplated hereby shall take place at the offices of Debevoise & Plimpton LLP, 919 Third Avenue, New York, New York 10022 at 9:30 a.m. (New York City time) on [●], 2018 or at such other time or place as the parties shall agree.

ARTICLE 3

CONDITIONS PRECEDENT

Section 3.01. Conditions Precedent to Obligations of the Pass Through Trustees . The obligation of each Pass Through Trustee hereunder, including the obligation of the Class C Trustee to make the loan contemplated by Article II, is subject to the fulfillment (or the waiver by such Pass Through Trustee) prior to or on the Series C Closing Date of the following conditions precedent:

(a) Authentication . The Company shall have tendered the Series C Equipment Notes being issued on the Series C Closing Date to the Loan Trustee for authentication, and the Loan Trustee shall have authenticated such Series C Equipment Notes and shall have tendered such Series C Equipment Notes to the Subordination Agent on behalf of the Class C Trustee, against receipt of the loan proceeds, in accordance with Section 2.02.

(b) No Changes in Law . No change shall have occurred after the date of this Amendment in applicable law or regulations thereunder or interpretations thereof by appropriate regulatory authorities or any court that would make it a violation of law or governmental regulations for the Class C Trustee to make the loan contemplated by Section 2.01 or to acquire the Series C Equipment Notes.

(c) Documentation . This Amendment and the following documents shall have been duly authorized, executed and delivered by the respective party or parties thereto (other than the Pass Through Trustees or the Loan Trustee), shall be in full force and effect and executed counterparts (or copies thereof where indicated) thereof shall have been delivered to each Pass Through Trustee:

(i) the Amended and Restated Intercreditor Agreement, dated as of the Class C Issuance Date, among the Pass Through Trustees, the Liquidity Providers and the Subordination Agent;

(ii) the Class C Trust Supplement;

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(iii) the Joinder to Note Purchase Agreement, dated as of the date hereof, by the Class C Trustee; and

(iv) the First Indenture Amendment.

(d) [Reserved.]

(e) Certain Closing Certificates . Each Pass Through Trustee shall have received the following:

(i) a certificate dated the Series C Closing Date of the Secretary or an Assistant Secretary of the Company, certifying as to (A) a copy of the resolutions of the Board of Directors of the Company or the executive or any other applicable committee thereof duly authorizing the transactions contemplated hereby and the execution, delivery and performance by the Company of this Amendment, the First Indenture Amendment, the Series C Equipment Notes and each other document required to be executed and delivered by the Company in accordance with the provisions hereof or thereof and (B) a copy of the certificate of incorporation and by-laws of the Company, as in effect on the Series C Closing Date;

(ii) a certificate or other evidence from the Secretary of State of the State of Delaware, dated as of a date reasonably near the Series C Closing Date, as to the due incorporation and good standing of the Company in such state;

(iii) an incumbency certificate of the Company as to the person or persons authorized to execute and deliver this Amendment, the First Indenture Amendment, the Series C Equipment Notes and each other document to be executed by the Company in connection with the transactions contemplated hereby and thereby, and the specimen signatures of such person or persons; and

(iv) one or more certificates of the Loan Trustee and the Subordination Agent certifying to the reasonable satisfaction of the Pass Through Trustees as to the due authorization, execution, delivery and performance by the Loan Trustee and the Subordination Agent of this Amendment, the First Indenture Amendment, the Series C Equipment Notes and each of the other Operative Documents, in each case to which the Loan Trustee or the Subordination Agent is or will be a party and any other documents to be executed by or on behalf of the Loan Trustee or the Subordination Agent in connection with the transactions contemplated hereby or thereby.

(f) Representations; No Event of Default or Event of Loss. On the Series C Closing Date, the following statements shall be correct: (i) the representations and

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Exhibit 4.3

warranties of the Company herein are correct in all material respects as though made on and as of such date, except to the extent that such representations and warranties relate solely to an earlier date (in which case such representations and warranties are correct on and as of such earlier date) and (ii) no event has occurred and is continuing that constitutes an Event of Default or an Event of Loss with respect to the Aircraft or would constitute an Event of Default or such an Event of Loss but for the requirement that notice be given or time elapse or both.

(g) Opinion of Counsel to the Company. Each Pass Through Trustee and the Loan Trustee shall have received (i) an opinion addressed to it from Thomas Canfield, Esq., General Counsel of the Company (or such internal counsel to the Company as shall be reasonably satisfactory to the Pass Through Trustees) substantially in the form set forth in Exhibit B-1 and (ii) an opinion addressed to it from Debevoise & Plimpton LLP substantially in the form set forth in Exhibit B-2 .

(h) Opinion of Counsel to WTNA, the Loan Trustee, the Pass Through Trustees and the Subordination Agent. Each Pass Through Trustee and the Loan Trustee shall have received an opinion addressed to it from Morris James LLP, special counsel for WTNA, the Loan Trustee, the Pass Through Trustees and the Subordination Agent, substantially in the form set forth in Exhibit C .

(i) Opinion of FAA Counsel. Each Pass Through Trustee and the Loan Trustee shall have received an opinion addressed to it from Daugherty, Fowler, Peregrin, Haught & Jenson, a Professional Corporation, special FAA counsel in Oklahoma City, Oklahoma, substantially in the form set forth in Exhibit D .

(j) Certification from the Company. Each Pass Through Trustee and the Loan Trustee shall have received a certificate or certificates signed by the chief financial or accounting officer, any Senior Vice President, the Treasurer, any Vice President or any Assistant Treasurer (or any other Responsible Officer) of the Company, dated the Series C Closing Date, certifying as to the correctness of each of the matters stated in Section 3.01(f) and satisfaction of the conditions set forth in Section 3.01(r).

(k) Certification from WTNA, the Loan Trustee and the Subordination Agent. Each Pass Through Trustee shall have received a certificate from WTNA in its individual capacity and as Loan Trustee and Subordination Agent, as applicable, dated the Series C Closing Date, signed by an authorized officer of WTNA in its individual capacity and as Loan Trustee and Subordination Agent, as applicable, certifying for each such entity that no Loan Trustee Liens or Other Party Liens attributable to it, as applicable, exist, and further certifying as to the correctness of each of the matters stated in Section 5.01.

(l) [Reserved.]

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(m) Insurance Matters . The Loan Trustee shall have received an insurance report of an independent insurance broker and the related certificates of insurance, each in form and substance reasonably satisfactory to the Loan Trustee, as to the compliance with the terms of Section 7.06 of the Indenture relating to insurance with respect to the Aircraft.

(n) No Proceedings . No action or proceeding shall have been instituted nor shall governmental action be threatened before any court or governmental agency, nor shall any order, judgment or decree have been issued or proposed to be issued by any court or governmental agency at the time of the Series C Closing to set aside, restrain, enjoin or prevent the completion and consummation of this Amendment or the transactions contemplated hereby.

(o) Funding of Class C Pass Through Trust . The Class C Trustee shall have received in immediately available funds an amount at least equal to the aggregate purchase price of the Series C Equipment Notes to be purchased from the Company by the Class C Trustee.

(p) [Reserved.]

(q) Governmental Approvals . All appropriate action required to have been taken prior to the Series C Closing Date by the FAA or any governmental or political agency, subdivision or instrumentality of the United States in connection with the transactions contemplated by this Amendment has been taken, and all orders, permits, waivers, authorizations, exemptions and approvals of such entities required to be in effect on the Series C Closing Date in connection with the transactions contemplated by this Amendment have been issued.

(r) Satisfaction of Conditions under the Note Purchase Agreement and Other Agreements . The conditions set forth in Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior to the Series C Closing), Section 2.02 of the Original Participation Agreement and Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing) to the issuance of Series C Equipment Notes shall have been complied with.

(s) Issuance of Related Series C Equipment Notes . Concurrently with the Series C Closing, the Company shall have issued “Series C Equipment Notes” constituting an “Additional Series Equipment Notes” under all of the Related Indentures in effect immediately prior to the Series C Closing.

(t) Ratings Confirmation . The Company shall have obtained the “Rating Agency Confirmation” with respect to the Class A Certificates and the Class B Certificates required by Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior

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to the Series C Closing) and the “Ratings Confirmation” with respect to the Class A Certificates and the Class B Certificates required by Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing).

Promptly upon the recording of the First Indenture Amendment pursuant to the Transportation Code and the receipt of appropriate and correct recording information from the FAA, the Company will cause Daugherty, Fowler, Peregrin, Haught & Jenson, a Professional Corporation, special FAA counsel in Oklahoma City, Oklahoma to deliver to the Subordination Agent, to the Pass Through Trustees, to the Loan Trustee and to the Company an opinion as to the due recording of such instrument and the lack of filing of any intervening documents with respect to the Aircraft (other than the filings in respect of the Original Indenture).

Section 3.02. Conditions Precedent to Obligations of the Company . The obligation of the Company to issue and sell the Series C Equipment Notes is subject to the fulfillment (or waiver by the Company) prior to or on the Series C Closing Date of the following conditions precedent:

(a) No Changes in Law . No change shall have occurred after the date of this Amendment in applicable law or regulations thereunder or interpretations thereof by appropriate regulatory authorities or any court that would make it a violation of law or governmental regulations for the Company to enter into any transaction contemplated hereby or by the Operative Documents, the Note Purchase Agreement or the other Pass Through Documents.

(b) Documentation . The documents referred to in Section 3.01(c) shall have been duly authorized, executed and delivered by the respective party or parties thereto (other than the Company), shall be in full force and effect and executed counterparts (or copies thereof where indicated) thereof shall have been delivered to the Company, and the Company shall have received such documents and evidence with respect to WTNA, each Liquidity Provider, the Loan Trustee, the Subordination Agent and each Pass Through Trustee as the Company reasonably requests in order to establish the consummation of the transactions contemplated by this Amendment, the taking of all corporate and other proceedings in connection therewith and compliance with the conditions herein set forth.

(c) FAA Filing . The First Indenture Amendment shall have been duly filed for recordation (or shall be in the process of being so duly filed for recordation) with the FAA pursuant to the Transportation Code.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

to the extent that such representations and warranties relate solely to an earlier date (in which case such representations and warranties shall have been correct on and as of such earlier date), and, insofar as such representations and warranties concern WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee, such party shall have so certified to the Company.

(e) Certain Opinions and Certificates . The Company shall have received each opinion referred to in Sections 3.01(h) and 3.01(i), each such opinion addressed to the Company or accompanied by a letter from the counsel rendering such opinion authorizing the Company to rely on such opinion as if it were addressed to the Company, and the certificates referred to in Sections 3.01(e)(iv) and 3.01(k).

(f) [Reserved.]

(g) No Proceedings . No action or proceeding shall have been instituted nor shall governmental action be threatened before any court or governmental agency, nor shall any order, judgment or decree have been issued or proposed to be issued by any court or governmental agency at the time of the Series C Closing to set aside, restrain, enjoin or prevent the completion and consummation of this Amendment or the transactions contemplated hereby.

(h) No Other Party Liens, etc . The Company shall have received a certificate from WTNA dated the Series C Closing Date, signed by an authorized officer of WTNA, certifying for each Pass Through Trustee that no Other Party Liens attributable to it exist and further certifying as to the correctness of each of the matters stated in Section 5.01.

(i) Payment for Series C Equipment Notes . The Company shall have been paid by the Class C Trustee the aggregate original principal amount of the Series C Equipment Notes being issued to the Class C Trustee as set forth on Schedule I hereto opposite the name of the Class C Pass Through Trust.

(j) Satisfaction of Conditions under the Note Purchase Agreement and Other Agreements . The conditions set forth in Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior to the Series C Closing), Section 2.02 of the Original Participation Agreement and Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing) to the issuance of Series C Equipment Notes shall have been complied with.

(k) Issuance of Related Series C Equipment Notes . Concurrently with the Series C Closing, the Company shall have issued “Series C Equipment Notes” constituting an “Additional Series Equipment Notes” under all of the Related Indentures in effect immediately prior to the Series C Closing.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

(l) Ratings Confirmation . The Company shall have obtained the “Rating Agency Confirmation” with respect to the Class A Certificates and the Class B Certificates required by Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior to the Series C Closing) and the “Ratings Confirmation” with respect to the Class A Certificates and the Class B Certificates required by Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing).

ARTICLE 4

REPRESENTATIONS AND WARRANTIES OF THE COMPANY

Section 4.01. Representations and Warranties of the Company . The Company represents and warrants that:

(a) Organization; Authority; Qualification . The Company is a corporation duly incorporated and validly existing in good standing under the laws of the State of Delaware, is a Certificated Air Carrier, is a Citizen of the United States, has the corporate power and authority to own its properties or hold them under lease and to enter into and perform its obligations under this Amendment, the First Indenture Amendment, the Series C Equipment Notes and the other Operative Documents to which it is a party and is duly qualified to do business as a foreign corporation in good standing in each other jurisdiction in which the failure to so qualify would have a material adverse effect on the consolidated financial condition of the Company and its subsidiaries, considered as a whole, and its jurisdiction of organization (as such term is used in Article 9 of the Uniform Commercial Code as in effect in the State of Delaware) is Delaware.

(b) Corporate Action and Authorization; No Violations . The execution, delivery and performance by the Company of this Amendment, the First Indenture Amendment, the Series C Equipment Notes and the other Operative Documents to which the Company is a party have been duly authorized by all necessary corporate action on the part of the Company, do not require any stockholder approval or approval or consent of any trustee or holder of any indebtedness or obligations of the Company, except such as have been duly obtained and are in full force and effect, and do not contravene any law, governmental rule, regulation, judgment or order binding on the Company or the certificate of incorporation or by-laws of the Company or contravene or result in a breach of, or constitute a default under, or result in the creation of any Lien (other than as permitted under the Indenture) upon the property of the Company under, any material indenture, mortgage, contract or other agreement to which the Company is a party or by which it or any of its properties may be bound or affected.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

the Company of any of the transactions contemplated hereby or thereby, requires the authorization, consent or approval of, the giving of notice to, the filing or registration with or the taking of any other action in respect of, the Department of Transportation, the FAA or any other federal or state governmental authority or agency, or the International Registry, except for (i) the registration of the issuance and sale of the Pass Through Certificates under the Securities Act and under the securities laws of any state or other jurisdiction in which the Pass Through Certificates may be offered for sale if the laws of such state or other jurisdiction require such action, (ii) the qualification of the Pass Through Trust Agreements under the Trust Indenture Act, (iii) the orders, permits, waivers, exemptions, authorizations and approvals of the regulatory authorities having jurisdiction over the Company’s ownership or operation of the Aircraft required to be obtained on or prior to the Series C Closing Date, which orders, permits, waivers, exemptions, authorizations and approvals have been duly obtained and are, or on the Series C Closing Date will be, in full force and effect, (iv) the filings and registrations referred to in Section 4.01(e) of the Original Participation Agreement and Section 4.01(e) hereof, (v) authorizations, consents, approvals, notices and filings required to be obtained, taken, given or made under securities or Blue Sky or similar laws of the various states and foreign jurisdictions and (vi) consents, approvals, notices, registrations and other actions required to be obtained, given, made or taken only after the date hereof.

(d) Valid and Binding Agreements . This Amendment, the First Indenture Amendment, the Series C Equipment Notes and each other Operative Document to which the Company is a party have been duly executed and delivered by the Company and constitute the legal, valid and binding obligations of the Company enforceable against the Company in accordance with their terms, except as the same may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the rights of creditors generally and by general principles of equity and except, in the case of the Indenture, as limited by applicable laws that may affect the remedies provided in the Indenture, which laws, however, do not make the remedies provided in the Indenture inadequate for the practical realization of the rights and benefits intended to be provided thereby.

(e) Filings and Recordation . Except for the filing for recordation pursuant to the Transportation Code of the First Indenture Amendment, no further filing or recording of any document is necessary under the laws of the United States or any state thereof as of the Series C Closing Date in order to establish and perfect the security interest in the Aircraft created under the Indenture in favor of the Loan Trustee as against the Company and any third parties in any applicable jurisdiction in the United States.

(f) Investment Company Act . The Company is not required to be registered as an “investment company” within the meaning of the Investment Company Act of 1940, as amended.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

(g) Title . As of the Series C Closing Date, (i) the Company has good title to the Aircraft, free and clear of Liens other than Permitted Liens, (ii) the Aircraft has been duly certificated by the FAA as to type and airworthiness in accordance with the terms of the Indenture, (iii) the Original Indenture has been duly recorded (or duly filed for recordation) with the FAA pursuant to the Transportation Code, (iv) the First Indenture Amendment has been duly filed for recordation (or shall be in the process of being so duly filed for recordation) with the FAA pursuant to the Transportation Code, (v) the Aircraft is duly registered with the FAA in the name of the Company, and (vi) the registration of the International Interests created under the Indenture with respect to the Aircraft has been effected on the International Registry in accordance with the Cape Town Treaty.

(h) Section 1110 . The Loan Trustee is entitled to the benefits of Section 1110 with respect to the Aircraft subject to the Lien of the Indenture on the Series C Closing Date.

(i) Security Interest . The Indenture creates in favor of the Loan Trustee, for the benefit of the Noteholders, the Indenture Indemnitees and the Related Indenture Indemnitees, a valid and perfected Lien on the Aircraft subject to the Lien of the Indenture on the Series C Closing Date, subject to no equal or prior Lien, except Permitted Liens.

(j) Licenses, Permits and Franchises . The Company holds all licenses, permits and franchises from the appropriate government entities necessary to authorize the Company lawfully to engage in air transportation and to carry on scheduled commercial passenger service as currently conducted, except where the failure to so hold any such license, permit or franchise would not have a material adverse effect on the financial condition or operations of the Company and its consolidated subsidiaries, taken as a whole.

(k) No Prior Amendments or Supplements . Except for the documents described in Section 3.01(c) of this Amendment, there have been no amendments or supplements to the documents referred to in Section 3.01(c) of the Original Participation Agreement.

ARTICLE 5

REPRESENTATIONS, WARRANTIES AND COVENANTS
OF WTNA

Section 5.01. Representations, Warranties and Covenants of WTNA . WTNA, generally, and as each of the Loan Trustee, the Subordination Agent and the Pass Through Trustee as it relates to it, represents, warrants and covenants that:

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

Section 8.01(a) of the Indenture and has full power, authority and legal right to enter into and perform its obligations under this Amendment, the First Indenture Amendment, the Series C Equipment Notes and each of the other Operative Documents and the Pass Through Documents to which WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee is a party and, in its capacity as Loan Trustee, to authenticate the Series C Equipment Notes and, in its capacity as Class C Trustee, to authenticate the Class C Certificates. WTNA is qualified to act as Loan Trustee under Section 8.01(c) of the Indenture. WTNA is a Citizen of the United States (without the use of a voting trust agreement), and will resign as the Loan Trustee under the Indenture promptly after it obtains actual knowledge that it has ceased to be such a Citizen of the United States.

(b) Due Authorization; No Violations . The execution, delivery and performance by WTNA, individually or in its capacity as Loan Trustee, Subordination Agent or Pass Through Trustee, as the case may be, of this Amendment, the First Indenture Amendment, the Series C Equipment Notes and each of the other Operative Documents and each of the Pass Through Documents to which WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee is a party, the performance by WTNA, individually or in its capacity as Loan Trustee, Subordination Agent or Pass Through Trustee, as the case may be, of its obligations hereunder or thereunder and the consummation on the Series C Closing Date of the transactions contemplated hereby or thereby, and the authentication of the Series C Equipment Notes and the Class C Certificates to be delivered on the Series C Closing Date: (i) have been duly authorized by all necessary action on the part of WTNA, the Loan Trustee, the Subordination Agent and each Pass Through Trustee, as the case may be, (ii) do not violate any law or regulation of the United States or of the state of the United States in which WTNA is located and which governs the banking and trust powers of WTNA or any order, writ, judgment or decree of any court, arbitrator or governmental authority applicable to WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee or any of their assets, (iii) will not violate any provision of the charter or by-laws of WTNA and (iv) will not violate any provision of, or constitute a default under, any mortgage, indenture, contract, agreement or undertaking to which any of WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee is a party or by which any of them or their respective properties may be bound or affected.

(c) Approvals . Neither the execution and delivery by WTNA, individually or in its capacity as Loan Trustee, Subordination Agent or Pass Through Trustee, as the case may be, of this Amendment, the First Indenture Amendment, the Series C Equipment Notes, any other Operative Document or any Pass Through Document to which WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee is a party, nor the consummation by WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee of any of the transactions contemplated hereby or thereby, requires the authorization, consent or approval of, the giving of notice to, the filing or registration with, or the taking

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

of any other action in respect of, (i) any governmental authority or agency of the United States or the state of the United States where WTNA is located and regulating the banking and trust powers of WTNA or (ii) any trustee or other holder of any debt of WTNA.

(d) Valid and Binding Agreements . This Amendment, the First Indenture Amendment, the Series C Equipment Notes, each other Operative Document and each Pass Through Document to which WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee is a party have been duly executed and delivered by WTNA, individually and in its capacity as Loan Trustee, Subordination Agent or Pass Through Trustee, as the case may be, and constitute the legal, valid and binding obligations of WTNA, the Loan Trustee, the Subordination Agent and such Pass Through Trustee, as the case may be, enforceable against it in accordance with its terms, except as the same may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the rights of creditors generally and by general principles of equity.

(e) No Loan Trustee Liens or Other Party Liens . It unconditionally agrees with and for the benefit of the parties to this Amendment that it will not directly or indirectly create, incur, assume or suffer to exist any Loan Trustee Lien or Other Party Lien attributable to it, and it agrees that it will, at its own cost and expense, promptly take such action as may be necessary to discharge and satisfy in full any such Lien.

(f) Intercreditor Agreement . The Series C Equipment Notes to be issued to the Subordination Agent pursuant hereto are being acquired by it to be held under the Intercreditor Agreement.

(g) Funds Transfer Fees . Each of WTNA, the Loan Trustee, the Subordination Agent and each Pass Through Trustee agrees that it will not impose any lifting charge, cable charge, remittance charge or any other charge or fee on any transfer by the Company of funds to, through or by WTNA, the Loan Trustee, the Subordination Agent or such Pass Through Trustee pursuant to this Amendment, the First Indenture Amendment, the Series C Equipment Notes, any other Operative Document or any Pass Through Document, except as may be otherwise agreed to in writing by the Company.

(h) Confidentiality . Each of WTNA, the Loan Trustee, the Subordination Agent and each Pass Through Trustee agrees to be bound by the terms of Section 10.16 of the Indenture.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

C Equipment Notes, any Operative Document or any Pass Through Document (other than franchise or other Taxes based on or measured by any fees or compensation received by any such Person for services rendered in connection with the transactions contemplated by this Amendment, the First Indenture Amendment, the Series C Equipment Notes, the other Operative Documents or the Pass Through Documents), and there are no Taxes payable by any Pass Through Trustee imposed by the State of Delaware or any political subdivision thereof in connection with the acquisition, possession or ownership by such Pass Through Trustee of any of the Equipment Notes (other than franchise or other Taxes based on or measured by any fees or compensation received by such Pass Through Trustee for services rendered in connection with the transactions contemplated by this Amendment, the First Indenture Amendment, the Series C Equipment Notes, the other Operative Documents or the Pass Through Documents) and, assuming that the Pass Through Trusts will not be taxable for Federal income tax purposes as corporations, but, rather, will be characterized for such purposes as grantor trusts or partnerships, the Pass Through Trusts will not be subject to any Taxes imposed by the State of Delaware or any political subdivision thereof.

(j) Limitation on Situs of Activities . Except with the consent of the Company, which shall not be unreasonably withheld, WTNA will act as Pass Through Trustee, Subordination Agent and Loan Trustee solely through its offices within the State of Delaware, except for such services as may be performed for it by independent agents in the ordinary course of business, but not directly by it, in other states.

(k) No Proceedings . There are no pending or, to its knowledge, threatened actions or proceedings against WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee before any court or administrative agency which individually or in the aggregate, if determined adversely to it, would materially adversely affect the ability of WTNA, the Loan Trustee, the Subordination Agent or any Pass Through Trustee to perform its obligations under this Amendment, the First Indenture Amendment, the Series C Equipment Notes, any other Operative Document or any Pass Through Document.

(l) Other Representations . The representations and warranties contained in Section 7.15 of the Basic Pass Through Trust Agreement and Section 7.04 of each Trust Supplement are true, complete and correct as of the Series C Closing Date.

ARTICLE 6

FEES AND EXPENSES

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

connection with the transactions contemplated hereby and (2) the following expenses incurred by the Loan Trustee, the Subordination Agent and the Pass Through Trustees in connection with the negotiation, preparation, execution and delivery of this Amendment, the First Indenture Amendment, the Series C Equipment Notes and the other documents or instruments referred to herein or therein:

(i) the reasonable fees, expenses and disbursements of (A) Morris James LLP, special counsel for the Loan Trustee, the Subordination Agent and the Pass Through Trustees, and (B) Daugherty, Fowler, Peregrin, Haught & Jenson, a Professional Corporation, special FAA counsel in Oklahoma City, Oklahoma, in each case to the extent actually incurred; and

(ii) all reasonable expenses actually incurred in connection with printing and document production or reproduction expenses.

ARTICLE 7

MISCELLANEOUS

Section 7.01. Effective Time . The amendments to the Original Participation Agreement contemplated hereby and the agreements set forth herein shall be effective as of the time of the Series C Closing. Effective as of the time of the Series C Closing, WTNA, as Class C Trustee, and WTNA, as Subordination Agent and as Noteholder of the Series C Equipment Notes, each shall be deemed to be a party to the Participation Agreement and shall have all of the rights and obligations of a “Pass Through Trustee”, a “Noteholder”, an “Indemnitee” and “Indenture Indemnitee”, as applicable, under the Participation Agreement and the other Operative Documents.

Section 7.02. Ratification and Agreements; Direction . Except as expressly amended hereby, the Original Participation Agreement shall remain in full force and effect, and this Amendment shall be construed as supplemental to the Original Participation Agreement and shall form a part thereof. For the avoidance of doubt, the parties hereto agree that, from and after the date hereof, the Series C Equipment Notes referred to herein shall constitute “Series C Equipment Notes” and “Equipment Notes”, the Class C Certificates referred to herein shall constitute “Class C Certificates” and “Pass Through Certificates”, the Class C Pass Through Trust referred to herein shall constitute the “Class C Pass Through Trust” and a “Pass Through Trust” and the Class C Trustee referred to herein shall constitute the “Class C Trustee” and a “Pass Through Trustee”, in each case for all purposes of the Participation Agreement, the Indenture and the other Operative Documents. The Subordination Agent, as record holder of the Equipment Notes, hereby authorizes, empowers and instructs the Loan Trustee to enter into, execute, deliver and perform its obligations under this Amendment and the First

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

Indenture Amendment, and each other document, instrument or writing as may be contemplated by, or necessary or convenient in connection with, any of the foregoing.

Section 7.03. Governing Law . THIS AMENDMENT HAS BEEN DELIVERED IN THE STATE OF NEW YORK AND SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

Section 7.04. Severability . To the extent permitted by applicable law, any provision of this Amendment which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.

Section 7.05. No Oral Modifications or Continuing Waivers; Consents . Subject to Section 9.03 of the Indenture, no terms or provisions of this Amendment may be changed, waived, discharged or terminated orally, but only by an instrument in writing signed by the party against which the enforcement of the change, waiver, discharge or termination is sought. No such change, waiver, discharge or termination shall be effective unless a signed copy thereof is delivered to the Loan Trustee.

Section 7.06. Effect of Headings and Table of Contents . The headings of the various Articles and Sections herein and in the Table of Contents are for convenience of reference only and do not define or limit any of the terms or provisions hereof.

Section 7.07. Successors and Assigns . All covenants, agreements, representations and warranties in this Amendment by the Company, by WTNA, individually or as Loan Trustee, Subordination Agent or Pass Through Trustee, or by any Noteholder, shall bind and inure to the benefit of and be enforceable by the Company, and subject to the terms of Section 6.02(e) of the Original Participation Agreement, its successors and permitted assigns, each Pass Through Trustee and any successor or other trustee under the Pass Through Trust Agreement to which it is a party, the Subordination Agent and its successor under the Intercreditor Agreement and the Loan Trustee and its successor under the Indenture, whether so expressed or not.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

Person, agrees and acknowledges that each Liquidity Provider is a third party beneficiary of the representations and warranties set forth in Section 5.01 of this Amendment, and that such Liquidity Provider may rely on such representations and warranties to the same extent as if such representations and warranties were made to such Liquidity Provider directly.

Section 7.09. Counterparts . This Amendment may be executed in any number of counterparts. Each of the parties hereto shall not be required to execute the same counterpart. Each counterpart of this Amendment including a signature page or pages executed by each of the parties hereto shall be an original counterpart of this Amendment, but all of such counterparts shall together constitute one instrument.

Section 7.10. Submission to Jurisdiction . Each of the parties hereto, to the extent it may do so under applicable law, for purposes hereof hereby (a) irrevocably submits itself to the non-exclusive jurisdiction of the courts of the State of New York sitting in the City of New York and to the non-exclusive jurisdiction of the United States District Court for the Southern District of New York, for the purposes of any suit, action or other proceeding arising out of this Amendment, the subject matter hereof or any of the transactions contemplated hereby brought by any party or parties hereto or thereto, or their successors or permitted assigns and (b) waives, and agrees not to assert, by way of motion, as a defense, or otherwise, in any such suit, action or proceeding, that the suit, action or proceeding is brought in an inconvenient forum, that the venue of the suit, action or proceeding is improper or that this Amendment or the subject matter hereof or any of the transactions contemplated hereby may not be enforced in or by such courts.

[Signature Pages Follow.]

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be duly executed by their respective officers thereunto duly authorized as of the date first above written.

SPIRIT AIRLINES, INC.

By:
    Name:
    Title:

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Pass Through Trustee under each of the Pass Through Trust Agreements

By:
    Name:
    Title:

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Subordination Agent

By:
    Name:
    Title:

Signature Page

First Amendment to Participation Agreement

(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

WILMINGTON TRUST, NATIONAL ASSOCIATION,
as Loan Trustee

By:
    Name:
    Title:

WILMINGTON TRUST, NATIONAL ASSOCIATION,
in its individual capacity as set forth herein

By:
    Name:
    Title:

Signature Page

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

SCHEDULE I to
FIRST AMENDMENT TO
PARTICIPATION AGREEMENT

AMENDED SCHEDULE I to
PARTICIPATION AGREEMENT

EQUIPMENT NOTES,
PURCHASERS AND ORIGINAL PRINCIPAL AMOUNTS



Purchaser	Description of Equipment Notes	Maturity	Interest Rate	Original Principal Amount
Spirit Airlines Pass Through Trust 2015-1A	Series 2015-1A-[Reg. No.] Equipment Note	April 1, 2028	4.100%	$[●]
Spirit Airlines Pass Through Trust 2015-1B	Series 2015-1B-[Reg. No.] Equipment Note	April 1, 2024	4.450%	$[●]
Spirit Airlines Pass Through Trust 2015-1C	Series 2015-1C-[Reg. No.] Equipment Note	April 1, 2023	[●]%	$[●]

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

SCHEDULE II to
FIRST AMENDMENT TO

PARTICIPATION AGREEMENT

AMENDED SCHEDULE II to
PARTICIPATION AGREEMENT

TRUST SUPPLEMENTS

Trust Supplement No. 2015-1A, dated as of the Original Issuance Date, between the Company and the Pass Through Trustee in respect of Spirit Airlines Pass Through Trust 2015-1A.

Trust Supplement No. 2015-1B, dated as of the Original Issuance Date, between the Company and the Pass Through Trustee in respect of Spirit Airlines Pass Through Trust 2015-1B.

Trust Supplement No. 2015-1C, dated as of the Class C Issuance Date, between the Company and the Pass Through Trustee in respect of Spirit Airlines Pass Through Trust 2015-1C.

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

EXHIBIT A to
FIRST AMENDMENT TO

PARTICIPATION AGREEMENT

FORM OF FIRST INDENTURE AMENDMENT

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

EXHIBIT B-1 to
FIRST AMENDMENT TO

PARTICIPATION AGREEMENT

FORM OF OPINION OF
COUNSEL FOR THE COMPANY

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

EXHIBIT B-2 to
FIRST AMENDMENT TO

PARTICIPATION AGREEMENT

FORM OF OPINION OF
SPECIAL COUNSEL FOR THE COMPANY

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

EXHIBIT C to
FIRST AMENDMENT TO

PARTICIPATION AGREEMENT

FORM OF OPINION OF
SPECIAL COUNSEL FOR THE LOAN TRUSTEE, THE PASS THROUGH TRUSTEES, THE SUBORDINATION AGENT AND WTNA

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.3

EXHIBIT D to
FIRST AMENDMENT TO

PARTICIPATION AGREEMENT

FORM OF OPINION OF SPECIAL FAA COUNSEL

First Amendment to Participation Agreement
(Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

FINAL FORM

FIRST AMENDMENT TO
INDENTURE AND SECURITY AGREEMENT

([Reg. No.])

Dated as of [●], 2018

between

SPIRIT AIRLINES, INC.,

and

WILMINGTON TRUST, NATIONAL ASSOCIATION,

as Loan Trustee

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

FIRST AMENDMENT TO
INDENTURE AND SECURITY AGREEMENT
([REG. NO.])

This FIRST AMENDMENT TO INDENTURE AND SECURITY AGREEMENT ([REG. NO.]), dated as of [●], 2018 (this “ First Indenture Amendment ”), is made by and between SPIRIT AIRLINES, INC., a Delaware corporation (together with its successors and permitted assigns, the “ Company ”), and WILMINGTON TRUST, NATIONAL ASSOCIATION, a national banking association, not in its individual capacity, except as expressly stated herein, but solely as Loan Trustee hereunder (together with its permitted successors hereunder, the “ Loan Trustee ”).

W I T N E S S E T H :

WHEREAS, capitalized terms used but not defined herein shall have the meanings ascribed to such terms in the Original Indenture referred to below;

WHEREAS, on the Closing Date, which occurred on [●], 20[●], the Company and the Loan Trustee entered into that certain Indenture and Security Agreement ([Reg. No.]), dated as of [●], 20[●], as supplemented by Indenture Supplement No. 1 thereto, dated [●], 20[●],with respect to one Airbus model [●] aircraft bearing manufacturer’s serial number [●] and United States registration number N[●] and two International Aero Engines AG (IAE) model [●] aircraft engines bearing manufacturer’s serial numbers [●] and [●], respectively, recorded by the FAA on [●], 20[●], and assigned Conveyance No. [●](the “ Original Indenture ”), pursuant to which, among other things, the Company issued to the Subordination Agent the Series A Equipment Notes and the Series B Equipment Notes, in each case in the applicable original principal amount, having the applicable maturity and bearing interest at the applicable Debt Rate as specified on Schedule I to the Original Indenture;

WHEREAS, in connection with the Original Indenture, the Company, the Class A Trustee, the Class B Trustee, the Subordination Agent, the Loan Trustee and WTNA in its individual capacity, entered into that certain Participation Agreement ([Reg. No.]), dated as of [●], 20[●] (the “ Original Participation Agreement ”), providing for the issuance by the Company of the Series A Equipment Notes and the Series B Equipment Notes secured by a security interest in the Company’s right, title and interest in and to the Aircraft and certain other property described in the Original Indenture (as further described in the Original Indenture, the “ Collateral ”);

WHEREAS, Section 2.02 of the Original Indenture provides that, subject to compliance with the conditions set forth in Section 4(a)(v) of the Note Purchase Agreement (as in effect immediately prior to the Series C Closing (as defined in the First PA Amendment referred to below)), Section 2.02 of the Original Participation Agreement

First Amendment to

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Exhibit 4.4

and Section 8.01(d) of the Intercreditor Agreement (as in effect immediately prior to the Series C Closing), the Company shall have the option to issue one or more Series of Additional Series Equipment Notes from time to time after the Closing Date;

WHEREAS, concurrently with the execution and delivery of this First Indenture Amendment, the Company, WTNA, as Class A Trustee, Class B Trustee and Class C Trustee (as defined in the First PA Amendment referred to below), the Subordination Agent and the Loan Trustee, and WTNA, in its individual capacity, entered into that certain First Amendment to Participation Agreement ([Reg. No.]), dated as of the date hereof (the “ First PA Amendment ”), pursuant to which, among other things, Series C Equipment Notes specified in Schedule I to the Indenture and substantially in the form set forth in Section 2.01 of the Indenture will be issued to the Subordination Agent;

WHEREAS, in connection with such issuance of the Series C Equipment Notes and other transactions contemplated by the First PA Amendment, the Company and the Loan Trustee desire to amend the Original Indenture to provide for the Company’s issuance of Series C Equipment Notes on the terms provided herein and therein;

WHEREAS, all things have been done to make the Series C Equipment Notes, when executed by the Company and authenticated and delivered by the Loan Trustee, the valid, binding and enforceable obligations of the Company; and

WHEREAS, all things necessary to make this First Indenture Amendment a legal, valid and binding obligation of the Company have been done and performed and have occurred;

NOW, THEREFORE, in consideration of the mutual agreements contained herein, the parties hereto agree as follows:

ARTICLE 1

Section 1.01 Issuance of Series C Equipment Notes . The Series C Equipment Notes being issued pursuant to the Indenture shall be dated the date of issuance thereof, and shall be issued with the maturity date and in the original principal amount, and shall bear interest at the applicable Debt Rate, in each case as specified in Schedule I to the Indenture. On the date hereof, each Series C

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Equipment Note shall be issued to the Subordination Agent on behalf of the Class C Pass Through Trust (as defined in the First PA Amendment) created under the Pass Through Trust Agreement related thereto.

Section 1.02 Series C Equipment Notes Related Provisions . For the avoidance of doubt, the parties hereto agree that, from and after the date hereof, the Series C Equipment Notes being issued as provided herein shall constitute “Series C Equipment Notes” and be included in “Equipment Notes” for all purposes of the Indenture and the other Operative Documents.

Section 1.03 Definitional Provisions .

(a) For purposes of this First Indenture Amendment, ( i ) the term “Indenture” means the Original Indenture as amended by this First Indenture Amendment and ( ii ) the term “Participation Agreement” means the Original Participation Agreement as amended by the First PA Amendment.

(b) All references in this First Indenture Amendment to designated “Articles”, “Sections”, “Subsections”, “Schedules”, “Exhibits”, “Annexes” and other subdivisions are to the designated Article, Section, Subsection, Schedule, Exhibit, Annex or other subdivision of this First Indenture Amendment, unless otherwise specifically stated.

(c) The words “herein”, “hereof” and “hereunder” and other words of similar import refer to this First Indenture Amendment as a whole and not to any particular Article, Section, Subsection, Schedule, Exhibit, Annex or other subdivision.

(d) Unless the context otherwise requires, whenever the words “including”, “include” or “includes” are used herein, they shall be deemed to be followed by the phrase “without limitation”.

(e) All references in this First Indenture Amendment to a Person shall include successors and permitted assigns of such Person.

ARTICLE II

Section 2.01 Amendment to Section 2.01 . Section 2.01 of the Original Indenture is hereby amended as follows:

(a) The twelfth paragraph of the form of Equipment Notes is deleted in its entirety and replaced with the following (including the footnotes):

“The indebtedness evidenced by this Equipment Note is[,] ¹ [( i ) to the extent and in the manner provided in the Indenture, subordinate and subject in

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Exhibit 4.4

right of payment to the prior payment in full of the Secured Obligations in respect of [Series A Equipment Notes] ² [Series A Equipment Notes and Series B Equipment Notes] ³ [Series A Equipment Notes, Series B Equipment Notes and Series C Equipment Notes] ⁴ [Series A Equipment Notes, Series B Equipment Notes, Series C Equipment Notes and [____] ⁵ ] ⁶ , and certain other Secured Obligations, and ( ii )] ⁷ to the extent and in the manner provided in each Related Indenture, subordinate and subject in right of payment to the prior payment in full under such Related Indenture of the “Secured Obligations” in respect of the “Equipment Notes” issued under such Related Indenture, and this Equipment Note is issued subject to such provisions. The Noteholder of this Equipment Note, by accepting the same, ( a ) agrees to and shall be bound by such provisions, ( b ) authorizes and directs the Loan Trustee or the Related Loan Trustee under the applicable Related Indenture, as appropriate, on such Noteholder’s behalf to take any action necessary or appropriate to effectuate the subordination as provided in the Indenture or the applicable Related Indenture and ( c ) appoints the Loan Trustee or the Related Loan Trustee under the applicable Related Indenture, as appropriate, as such Noteholder’s attorney-in-fact for such purpose.

¹ To be inserted in the case of a Series A Equipment Note.

² To be inserted in the case of a Series B Equipment Note.

³ To be inserted in the case of a Series C Equipment Note.


⁴	To be inserted in the case of the Series of Additional Series Equipment Notes ranked most senior in priority of payment among all Series of Additional Series Equipment Notes.


⁵	To insert each Series of Additional Series Equipment Notes that rank senior in priority of payment to the Series of Additional Series Equipment Notes being issued.


⁶	To be inserted in the case of each Series of Additional Series Equipment Notes other than the Series of Additional Series Equipment Notes ranked most senior in priority of payment among all Series of Additional Series Equipment Notes.


⁷	To be inserted in the case of a Series B Equipment Note, a Series C Equipment Note or an Additional Series Equipment Note.”

Section 2.02 Amendment to Section 2.02 . Section 2.02 of the Original Indenture is hereby amended as follows:

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(a) The first paragraph is deleted in its entirety and replaced with the following:

“Section 2.02 Issuance and Terms of Equipment Notes . The Equipment Notes shall be dated the date of issuance thereof, shall be issued in ( a ) separate Series consisting of Series A Equipment Notes, Series B Equipment Notes, Series C Equipment Notes and one or more Additional Series Equipment Notes (if issued) and ( b ) the maturities and principal amounts and shall bear interest at the applicable Debt Rates specified in Schedule I. On the date of original issuance thereof, each Equipment Note shall be issued to the Subordination Agent on behalf of each of the Pass Through Trustees for the applicable Pass Through Trust created under the Pass Through Trust Agreements referred to in Schedule II. Subject to compliance with the conditions set forth in Section 4(a)(v) of the Note Purchase Agreement, Section 2.02 of the Participation Agreement and Section 8.01(c) or 8.01(d) of the Intercreditor Agreement, as applicable, the Company shall have the option after the Class C Issuance Date, from time to time ( i ) to issue one or more Series of Additional Series Equipment Notes under this Indenture, ( ii ) to redeem all but not less than all of the Series B Equipment Notes or all but not less than all of the Series C Equipment Notes (or all but not less than all of any Series of Additional Series Equipment Notes) pursuant to, and in accordance with, the provisions of Section 2.11(b) and to issue under this Indenture new Equipment Notes with the same Series designation as, but with terms that may be the same as or different from those of, the redeemed Equipment Notes, and (iii) following the payment in full of all but not less than all of the Series B Equipment Notes or all but not less than all of the Series C Equipment Notes (or all but not less all of any Series of Additional Series Equipment Notes), to issue new Equipment Notes with the same Series designation as, but with terms that may be the same as or different from those of, such Equipment Notes that have been paid in full. If new Series B Equipment Notes, new Series C Equipment Notes, Additional Series Equipment Notes or new Additional Series Equipment Notes are issued after the Class C Issuance Date in accordance with the immediately preceding sentence, such Equipment Notes shall be dated the date of original issuance thereof and shall have such maturities, principal amounts and interest rate as specified in an amendment to this Indenture. The Equipment Notes shall be issued in registered form only. The Equipment Notes shall be issued in denominations of $1,000 and integral multiples thereof, except that one Equipment Note of each Series may be in an amount that is not an integral multiple of $1,000. For the avoidance of doubt, if the Company shall issue new “Series B Equipment Notes” or new “Series C Equipment Notes” or “Additional Series Equipment Notes” of any Series or new “Additional Series Equipment Note”, in each case under any Related Indenture, the Company may, but shall not be required to, issue, as the case may be, new Series B Equipment Notes or new

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[Reg. No.]

Exhibit 4.4

Series C Equipment Notes or Additional Series Equipment Notes of the same Series or new Additional Series Equipment Notes of the same Series, in each case under this Indenture.”

(b) The second paragraph is deleted in its entirety and replaced with the following:

“Each Equipment Note shall bear interest at the Debt Rate specified for the applicable Series (calculated on the basis of a year of 360 days comprised of twelve 30-day months), payable in arrears on each Payment Date on the unpaid principal amount thereof from time to time outstanding from the most recent Payment Date to which interest has been paid or duly provided for (or, if no interest has been so paid or provided for, from the date of issuance of such Equipment Note) until such principal amount is paid in full, as further provided in the form of Equipment Note set forth in Section 2.01. The principal amount of each Series A Equipment Note, each Series B Equipment Note and each Series C Equipment Note shall be payable in installments or in a single payment on the Payment Dates set forth in such Equipment Note, each such installment, if any, to be in an amount computed by multiplying the original principal amount of such Equipment Note by the corresponding percentage set forth in Schedule I hereto applicable to such Series, the applicable portion of which shall be attached as Schedule I to such Equipment Note, opposite the Payment Date on which such installment is due. Each Additional Series Equipment Note, if issued, shall be payable in installments or in a single payment as set forth in an amendment to this Indenture, and if payable in installments, such installments shall be calculated as set forth in the preceding sentence. Notwithstanding the foregoing, the final payment made under each Equipment Note shall be in an amount sufficient to discharge in full the unpaid principal amount and all accrued and unpaid interest on, and any other amounts due under, such Equipment Note. Each Equipment Note shall bear interest, payable on demand, at the Past Due Rate (and not at the Debt Rate) (calculated on the basis of a year of 360 days comprised of twelve 30‑day months) on any principal amount and (to the extent permitted by applicable law) Make-Whole Amount, if any, interest and any other amounts payable thereunder not paid when due for any period during which the same is overdue, in each case for the period the same is overdue. Amounts shall be overdue under an Equipment Note if not paid in the manner provided therein or in this Indenture when due (whether at stated maturity, by acceleration or otherwise). Notwithstanding anything to the contrary contained herein, if any date on which a payment hereunder or under any Equipment Note becomes due and payable is not a Business Day, then such payment shall not be made on such scheduled date but shall be made on the next succeeding Business Day with the same force and effect as if made on such scheduled date, and if such payment is made on such next

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Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

succeeding Business Day, no interest shall accrue on the amount of such payment from and after such scheduled date.”

Section 2.03 Amendment to Section 2.11 . Section 2.11(b) of the Original Indenture is hereby amended by deleting it in its entirety and replacing it with the following:

“(b) All of the Series B Equipment Notes or all of the Series C Equipment Notes or all of any Series of Additional Series Equipment Notes (or any combination of the foregoing) may be redeemed by the Company upon at least 30 days’ revocable prior written notice to the Loan Trustee and the Noteholders of each Series to be redeemed, and such Series of Equipment Notes being redeemed pursuant to this Section 2.11(b) shall be redeemed in whole at a redemption price equal to 100% of the unpaid principal amount thereof, together with accrued and unpaid interest thereon to (but excluding) the date of redemption and all other Secured Obligations owed or then due and payable to the Noteholders of such Series, plus Make-Whole Amount, if any; provided that:

(i) no redemption shall be permitted under this Section 2.11(b) unless, simultaneously with such redemption, the Related Series B Equipment Notes (in the case of redemption hereunder of Series B Equipment Notes) or the Related Series C Equipment Notes (in the case of redemption hereunder of Series C Equipment Notes) or the Related Additional Series Equipment Notes in respect of the Additional Series Equipment Notes being redeemed (in the case of redemption hereunder of any Additional Series Equipment Notes), as the case may be, shall also be redeemed; and

(ii) if, simultaneously with such redemption, new Series B Equipment Notes (in the case of redemption hereunder of Series B Equipment Notes) or new Series C Equipment Notes (in the case of redemption hereunder of Series C Equipment Notes) or new Additional Series Equipment Notes of the same Series designation as the Additional Series Equipment Notes being redeemed (in the case of redemption hereunder of Additional Series Equipment Notes), in any such case, having terms that may be the same as or different from those of the redeemed Equipment Notes, are being issued, such new Equipment Notes shall be issued in accordance with Section 2.02 of the Participation Agreement, Section 4(a)(v) of the Note Purchase Agreement and Section 8.01(c) of the Intercreditor Agreement.”

Section 2.04 Amendment to Section 2.13 . Section 2.13(a) of the Original Indenture is hereby amended by deleting it in its entirety and replacing it with the following:

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[Reg. No.]

Exhibit 4.4

“(a) The indebtedness evidenced by the Series B Equipment Notes is, to the extent and in the manner provided in this Indenture, subordinate and subject in right of payment to the prior payment in full of the Secured Obligations in respect of the Series A Equipment Notes, and the Series B Equipment Notes are issued subject to such provisions. The indebtedness evidenced by the Series C Equipment Notes is, to the extent and in the manner provided in this Indenture, subordinate and subject in right of payment to the prior payment in full of the Secured Obligations in respect of the Series A Equipment Notes and the Series B Equipment Notes, and the Series C Equipment Notes are issued subject to such provisions. The indebtedness evidenced by the Series of Additional Series Equipment Notes ranked most senior in priority of payment among all Series of Additional Series Equipment Notes, if issued, will be, to the extent and in the manner provided in this Indenture (as this Indenture may be amended in connection with any such issuance of such most senior Series of Additional Series Equipment Notes), subordinate and subject in right of payment to the prior payment in full of the Secured Obligations in respect of the Series A Equipment Notes, the Series B Equipment Notes and the Series C Equipment Notes, and any such most senior Series of Additional Series Equipment Notes, if issued, shall be issued subject to such provisions. The indebtedness evidenced by any Additional Series Equipment Notes (other than the Series of Additional Series Equipment Notes ranked most senior in priority of payment among all Series of Additional Series Equipment Notes), if issued, will be, to the extent and in the manner provided in this Indenture (as this Indenture may be amended in connection with any such issuance of such Additional Series Equipment Notes), subordinate and subject in right of payment to the prior payment in full of the Secured Obligations in respect of the Series A Equipment Notes, the Series B Equipment Notes, the Series C Equipment Notes and each Series of Additional Series Equipment Notes that rank senior in priority of payment to such Additional Series Equipment Notes, and any such Additional Series Equipment Notes, if issued, shall be issued subject to such provisions. The indebtedness evidenced by the Series A Equipment Notes, the Series B Equipment Notes and the Series C Equipment Notes is, and the indebtedness evidenced by any Additional Series Equipment Notes, if issued, will be, to the extent and in the manner provided in each Related Indenture, subordinate and subject in right of payment to the prior payment in full under such Related Indenture of the “Secured Obligations” in respect of the “Equipment Notes” issued under such Related Indenture, and the Series A Equipment Notes, the Series B Equipment Notes and the Series C Equipment Notes are, and any Additional Series Equipment Notes shall be, issued subject to such provisions. By acceptance of its Equipment Notes of any Series, each Noteholder of such Series ( i ) agrees to and shall be bound by such provisions, ( ii ) authorizes and directs the Loan Trustee or the Related Loan Trustee under the applicable Related Indenture, as appropriate, on such Noteholder’s behalf to take

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[Reg. No.]

Exhibit 4.4

any action necessary or appropriate to effectuate the subordination as provided in this Indenture and the applicable Related Indenture and ( iii ) appoints the Loan Trustee or the Related Loan Trustee under the applicable Related Indenture, as appropriate, as such Noteholder’s attorney-in-fact for such purpose.”

Section 2.05 Amendment to Section 3.01 . Section 3.01 of the Original Indenture is hereby amended by deleting clauses “third” and “fourth” in their entirety and replacing them with the following clauses “third” and “fourth”, respectively, and adding immediately thereafter the following clause “fifth”:

“ third , after giving effect to clause “second” above, so much of such payment remaining as is required to pay in full the aggregate amount of the payment or payments of principal amount and interest (as well as any interest on any overdue principal amount and, to the extent permitted by applicable law, on any overdue interest and any other overdue amounts) then due under all Series C Equipment Notes shall be distributed to the Noteholders of Series C Equipment Notes ratably, without priority of one over the other, in the proportion that the amount of such payment or payments then due under each Series C Equipment Note bears to the aggregate amount of the payments then due under all Series C Equipment Notes;

fourth , after giving effect to clause “third” above (and except as otherwise provided in an amendment to this Indenture pursuant to paragraph (xv) or (xvi) of Section 9.01) so much of such payment remaining as is required to pay in full the aggregate amount of the payment or payments of principal amount and interest (as well as any interest on any overdue principal amount and, to the extent permitted by applicable law, on any overdue interest and any other overdue amounts) then due under all Additional Series Equipment Notes of a specified Series shall be distributed to the Noteholders of Additional Series Equipment Notes of such Series ratably, without priority of one over the other, in the proportion that the amount of such payment or payments then due under each Additional Series Equipment Note of such Series bears to the aggregate amount of the payments then due under all Additional Series Equipment Notes of such Series, provided that this clause “fourth” shall apply to each Series of Additional Series Equipment Notes in order of priority of payment; and

fifth ¸ the balance, if any, of such installment remaining thereafter shall be distributed to the Company.”

Section 2.06 Amendment to Section 3.02 . Section 3.02 of the Original Indenture is hereby amended by deleting paragraph “(iii)” of clause “second” in its

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Indenture and Security Agreement (Spirit 2015-1 EETC)

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Exhibit 4.4

entirety and replacing it with the following paragraph “(iii)” and adding immediately thereafter the following paragraph “(iv)”:

“(iii) after giving effect to paragraph (ii) above, so much of such payment remaining as is required to pay the amounts specified in paragraph (iii) of clause “third” of Section 3.03 plus Make-Whole Amount, if any, then due and payable in respect of the Series C Equipment Notes; and

(iv) after giving effect to paragraph (iii) above (and except as otherwise provided in an amendment to this Indenture pursuant to paragraph (xv) or (xvi) of Section 9.01), so much of such payment remaining as is required to pay the amounts specified in paragraph (iv) of clause “third” of Section 3.03 plus Make-Whole Amount, if any, then due and payable in respect of Additional Series Equipment Notes of a specified Series, provided that this paragraph (iv) shall apply to each Series of Additional Series Equipment Notes in order of priority of payment;”

Section 2.07 Amendment to Section 3.03 . Section 3.03 of the Original Indenture is hereby amended as follows:

(a) Clause “third” is deleted in its entirety and replaced with the following:

“ third , after giving effect to clause “second” above:

(i) so much of such payments or amounts remaining as is required to pay in full the aggregate unpaid principal amount of all Series A Equipment Notes, and the accrued but unpaid interest and other amounts due thereon and all other Secured Obligations in respect of the Series A Equipment Notes to the date of distribution, shall be distributed to the Noteholders of Series A Equipment Notes, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the aggregate unpaid principal amount of all Series A Equipment Notes held by each holder thereof plus the accrued but unpaid interest and other amounts due in respect thereof hereunder or thereunder to the date of distribution bears to ( y ) the aggregate unpaid principal amount of all Series A Equipment Notes held by all holders thereof plus the accrued but unpaid interest and other amounts due thereon to the date of distribution;

(ii) after giving effect to paragraph (i) above, so much of such payments or amounts remaining as is required to pay in full the aggregate unpaid principal amount of all Series B Equipment Notes, and the accrued but unpaid interest and other amounts due thereon and all other Secured

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Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

Obligations in respect of the Series B Equipment Notes to the date of distribution, shall be distributed to the Noteholders of Series B Equipment Notes, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the aggregate unpaid principal amount of all Series B Equipment Notes held by each holder thereof plus the accrued but unpaid interest and other amounts due in respect thereof hereunder or thereunder to the date of distribution bears to ( y ) the aggregate unpaid principal amount of all Series B Equipment Notes held by all holders thereof plus the accrued but unpaid interest and other amounts due thereon to the date of distribution;

(iii) after giving effect to paragraph (ii) above, so much of such payments or amounts remaining as is required to pay in full the aggregate unpaid principal amount of all Series C Equipment Notes, and the accrued but unpaid interest and other amounts due thereon and all other Secured Obligations in respect of the Series C Equipment Notes to the date of distribution, shall be distributed to the Noteholders of Series C Equipment Notes, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the aggregate unpaid principal amount of all Series C Equipment Notes held by each holder thereof plus the accrued but unpaid interest and other amounts due in respect thereof hereunder or thereunder to the date of distribution bears to ( y ) the aggregate unpaid principal amount of all Series C Equipment Notes held by all holders thereof plus the accrued but unpaid interest and other amounts due thereon to the date of distribution;

(iv) after giving effect to paragraph (iii) above (and except as otherwise provided in an amendment to this Indenture pursuant to paragraph (xv) or (xvi) of Section 9.01), so much of such payments or amounts remaining as is required to pay in full the aggregate unpaid principal amount of all Additional Series Equipment Notes of a specified Series, and the accrued but unpaid interest and other amounts due thereon and all other Secured Obligations in respect of the Additional Series Equipment Notes of such Series to the date of distribution, shall be distributed to the Noteholders of Additional Series Equipment Notes of such Series, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the aggregate unpaid principal amount of all Additional Series Equipment Notes of such Series held by each holder thereof plus the accrued but unpaid interest and other amounts

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Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

due in respect thereof hereunder or thereunder to the date of distribution bears to ( y ) the aggregate unpaid principal amount of all Additional Series Equipment Notes of such Series held by all holders thereof plus the accrued but unpaid interest and other amounts due thereon to the date of distribution, provided that this paragraph (iv) shall apply to each Series of Additional Series Equipment Notes in order of priority of payment;

(v) after giving effect to paragraph (iv) above, so much of such payments or amounts remaining as is required to pay in full the amounts then due and covered by clause “first” of Section 3.03 of each Defaulted Operative Indenture shall be distributed to the Related Loan Trustee under each respective Defaulted Operative Indenture, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in accordance with the priorities and prorations in such clause “first”;

(vi) after giving effect to paragraph (v) above, so much of such payments or amounts remaining as is required to pay in full the amounts then due and covered by clause “second” of Section 3.03 of each Defaulted Operative Indenture shall be distributed to the Related Loan Trustee under each respective Defaulted Operative Indenture, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in accordance with the priorities and prorations in such clause “second”;

(vii) after giving effect to paragraph (vi) above, so much of such payments or amounts remaining as is required to pay in full the aggregate amount of the payment or payments of principal amount and interest (as well as any interest on any overdue principal amount and, to the extent permitted by applicable law, on any overdue interest and any other overdue amounts) then due under all Related Series A Equipment Notes, if any, issued under any Defaulted Operative Indenture shall be distributed to the Related Loan Trustee under each respective Defaulted Operative Indenture under which any Related Series A Equipment Notes are outstanding, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the amount of such payment or payments then due under all Related Series A Equipment Notes issued under each Defaulted Operative Indenture bears to ( y ) the aggregate amount of the payments then due under all Related Series A Equipment Notes issued under all Defaulted Operative Indentures;

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[Reg. No.]

Exhibit 4.4

(viii) after giving effect to paragraph (vii) above, so much of such payments or amounts remaining as is required to pay in full the aggregate amount of the payment or payments of principal amount and interest (as well as any interest on any overdue principal amount and, to the extent permitted by applicable law, on any overdue interest and any other overdue amounts) then due under all Related Series B Equipment Notes, if any, issued under any Defaulted Operative Indenture shall be distributed to the Related Loan Trustee under each respective Defaulted Operative Indenture under which any Related Series B Equipment Notes are outstanding, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the amount of such payment or payments then due under all Related Series B Equipment Notes issued under each Defaulted Operative Indenture bears to ( y ) the aggregate amount of the payments then due under all Related Series B Equipment Notes issued under all Defaulted Operative Indentures;

(ix) after giving effect to paragraph (viii) above, so much of such payments or amounts remaining as is required to pay in full the aggregate amount of the payment or payments of principal amount and interest (as well as any interest on any overdue principal amount and, to the extent permitted by applicable law, on any overdue interest and any other overdue amounts) then due under all Related Series C Equipment Notes, if any, issued under any Defaulted Operative Indenture shall be distributed to the Related Loan Trustee under each respective Defaulted Operative Indenture under which any Related Series C Equipment Notes are outstanding, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the amount of such payment or payments then due under all Related Series C Equipment Notes issued under each Defaulted Operative Indenture bears to ( y ) the aggregate amount of the payments then due under all Related Series C Equipment Notes issued under all Defaulted Operative Indentures;

(x) after giving effect to paragraph (ix) above (and except as otherwise provided in amendments to the applicable Related Indentures pursuant to paragraph (xv) or (xvi) of Section 9.01 thereof), so much of such payments or amounts remaining as is required to pay in full the aggregate amount of the payment or payments of principal amount and interest (as well as any interest on any overdue principal amount and, to the extent permitted by applicable law, on any overdue interest and any other overdue amounts) then due under all Related Additional Series

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Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

Equipment Notes of a specified Series, if any, issued under any Defaulted Operative Indenture shall be distributed to the Related Loan Trustee under each respective Defaulted Operative Indenture under which any Related Additional Series Equipment Notes of such Series are outstanding, and in case the aggregate amount so to be distributed shall be insufficient to pay in full as aforesaid, then ratably, without priority of one over the other, in the proportion that ( x ) the amount of such payment or payments then due under all Related Additional Series Equipment Notes of such Series issued under each Defaulted Operative Indenture bears to ( y ) the aggregate amount of the payments then due under all Related Additional Series Equipment Notes of such Series issued under all Defaulted Operative Indentures, provided that this paragraph (x) shall apply to each Series of Additional Series Equipment Notes in order of priority of payment; and

(xi) after giving effect to paragraph (x) above, if any Related Equipment Note is outstanding, any of such payments or amounts remaining and any invested Permitted Investments shall be held by the Loan Trustee in an Eligible Account in accordance with the provisions of Section 3.07 (and invested as provided in Section 5.06) as additional security for the Related Secured Obligations, and such amounts (and any investment earnings thereon) shall be distributed from time to time in accordance with the foregoing provisions of this clause “third” as and to the extent any such Related Secured Obligation shall at any time and from time to time become due and remain unpaid after the giving of any required notice and the expiration of any applicable grace period; and, upon the payment in full of all such Related Secured Obligations the balance, if any, of any such remaining amounts and investment earnings thereon shall be applied as provided in clause “fourth” of this Section 3.03; and”

Section 2.08 Amendment to Section 9.01 . Section 9.01 of the Original Indenture is hereby amended by deleting clauses (xv) and (xvi) thereof in their entirety and replacing it with the following:

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Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

for the issuance of pass through certificates by any pass through trust that acquires any such Additional Series Equipment Notes (and Related Additional Series Equipment Notes), new Series B Equipment Notes (and new Related Series B Equipment Notes), new Series C Equipment Notes (and new Related Series C Equipment Notes) or new Additional Series Equipment Notes (and new Related Additional Series Equipment Notes) and to make changes relating to any of the foregoing (including, without limitation, to provide for any prefunding mechanism in connection therewith or to provide for the priority in payment among different Series of Additional Series Equipment Notes) and to provide for any credit support for any pass through certificates relating to any such Additional Series Equipment Notes (and Related Additional Series Equipment Notes), new Series B Equipment Notes (and new Related Series B Equipment Notes), new Series C Equipment Notes (and new Related Series C Equipment Notes) or new Additional Series Equipment Notes (and new Related Additional Series Equipment Notes) (including, without limitation, to secure claims for fees, interest, expenses, reimbursement of advances and other obligations arising from such credit support (including, without limitation, to specify such credit support as a “Liquidity Facility” and the provider of any such credit support as a “Liquidity Provider” and, if such Liquidity Facility is to be comprised of more than one instrument, to incorporate appropriate mechanics for multiple Liquidity Facilities for a single Pass Through Trust)); provided that any such Additional Series Equipment Notes, new Series B Equipment Notes, new Series C Equipment Notes or new Additional Series Equipment Notes, as the case may be, are issued in accordance with Section 4(a)(v) of the Note Purchase Agreement, Section 2.02 of the Participation Agreement and Section 8.01(c) or 8.01(d) of the Intercreditor Agreement, as applicable, and ( xvi ) to provide for the issuance of “Additional Series Equipment Notes” of one or more Series or new “Series B Equipment Notes” or new “Series C Equipment Notes” or new “Additional Series Equipment Notes” in each case under any or all Related Indentures and other matters incidental or relating thereto.”

ARTICLE III

Section 3.01 Amendment to Schedule I . Schedule I to the Original Indenture is hereby amended by deleting it in its entirety and replacing it with Schedule I to this First Indenture Amendment (it being agreed and understood that no amendments are being made to the maturity date, original principal amount, Debt Rate, Make-Whole Spread or amortization schedule of the Series A Equipment Notes or the Series B Equipment Notes).

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

Section 3.02 Amendment to Schedule II . Schedule II to the Original Indenture is hereby amended by deleting it in its entirety and replacing it with Schedule II to this First Indenture Amendment.

ARTICLE IV

Section 4.01 Amendment to Annex A . Annex A to the Original Indenture is amended as follows:

(a) The definition of “ Additional Series ” or “ Additional Series Equipment Notes ” is deleted in its entirety and replaced with the following:

(b) The definition of “ Class A Pass Through Trust ” is deleted in its entirety and replaced with the following:

(d) The definition of “ Debt Rate ” is deleted in its entirety and replaced with the following:

“ Debt Rate ” means ( i ) with respect to any Series of Equipment Notes, the rate per annum specified for the applicable Series as such in Schedule I to

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

the Indenture (as amended, in the case of any Additional Series, new Series B Equipment Notes, new Series C Equipment Notes or new Additional Series issued pursuant to Section 2.02 of the Indenture, at the time of issuance of such Series), and ( ii ) for any other purpose, with respect to any period, the weighted average interest rate per annum during such period borne by the outstanding Equipment Notes, excluding in each case any interest payable at the Past Due Rate.

(e) The definition of “ Deposit Agreement ” is deleted in its entirety and replaced with the following:

(f) The definition of “ Escrow Agreement ” is deleted in its entirety and replaced with the following:

(g) The definition of “ Intercreditor Agreement ” is deleted in its entirety and replaced with the following:

“ Intercreditor Agreement ” means that certain Amended and Restated Intercreditor Agreement (2015-1), dated as of the Class C Issuance Date, among the Pass Through Trustees, the Liquidity Providers and the Subordination Agent, as the same may be further amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligations of the Company, no amendment, modification or supplement to, or substitution or replacement of, such

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

Intercreditor Agreement shall be effective unless consented to by the Company.

(h) The definition of “ Issuance Date ” is deleted in its entirety.

(i) The definition of “ Make-Whole Spread ” is deleted in its entirety and replaced with the following:

(j) The definition of “ Note Purchase Agreement ” is deleted in its entirety and replaced with the following:

(k) The definition of “ Pass Through Trust ” is deleted in its entirety and replaced with the following:

(l) The definition of “ Pass Through Trust Agreement ” is deleted in its entirety and replaced with the following:

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

supplemented or otherwise modified from time to time in accordance with its terms.

(m) The definition of “ Related Additional Series Equipment Notes ” is deleted in its entirety and replaced with the following:

(n) The definition of “ Series ” is deleted in its entirety and replaced with the following:

(o) The following definitions shall be added to Annex A to the Original Indenture in alphabetical order:

“ Class C Certificates ” means Pass Through Certificates issued by the Class C Pass Through Trust.

“ Class C Issuance Date ” means [●], 2018.

“ Class C Trustee ” means the trustee for the Class C Pass Through Trust.

“ Original Issuance Date ” means August 11, 2015.

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

ARTICLE V

Section 5.01 Effective Time of Amendments . The amendments to the Original Indenture contemplated hereby and the agreements set forth herein shall be effective as of the time of the Series C Closing.

Section 5.02 Ratification . Except as expressly amended hereby, the Original Indenture shall remain in full force and effect in all respects, and this First Indenture Amendment shall be construed as supplemental to the Original Indenture and shall form a part thereof.

Section 5.03 Severability . To the extent permitted by applicable law, any provision of this First Indenture Amendment that is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.

Section 5.04 No Oral Modification or Continuing Waivers . No terms or provisions of this First Indenture Amendment may be changed, waived, discharged or terminated orally, but only by an instrument in writing signed by the Company and the Loan Trustee, in compliance with Article IX of the Indenture.

Section 5.05 Successors and Assigns . The terms and provisions contained herein shall bind and inure to the benefit of, and be enforceable by, each of the parties hereto and the successors and permitted assigns of each, all as provided herein and in the Indenture.

Section 5.06 Headings . The headings of the various Articles and Sections herein are for convenience of reference only and shall not define or limit any of the terms or provisions hereof.

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

Amendment including a signature page or pages executed by each of the parties hereto shall be an original counterpart of this First Indenture Amendment, but all of such counterparts together shall constitute one instrument.

Section 5.08 Governing Law . THIS FIRST INDENTURE AMENDMENT HAS BEEN DELIVERED IN THE STATE OF NEW YORK AND SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

Section 5.09 Submission to Jurisdiction . Each of the parties hereto, and by acceptance of Equipment Notes, each Noteholder, to the extent it may do so under applicable law, for purposes hereof hereby ( a ) irrevocably submits itself to the non-exclusive jurisdiction of the courts of the State of New York sitting in the City of New York and to the non-exclusive jurisdiction of the United States District Court for the Southern District of New York, for the purposes of any suit, action or other proceeding arising out of this First Indenture Amendment, the subject matter hereof or any of the transactions contemplated hereby brought by any party or parties hereto or thereto, or their successors or permitted assigns and ( b ) waives, and agrees not to assert, by way of motion, as a defense, or otherwise, in any such suit, action or proceeding, that the suit, action or proceeding is brought in an inconvenient forum, that the venue of the suit, action or proceeding is improper or that this First Indenture Amendment or the Equipment Notes or the subject matter hereof or any of the transactions contemplated hereby may not be enforced in or by such courts.

[Signature Pages Follow.]

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

IN WITNESS WHEREOF, the parties hereto have caused this First Indenture Amendment to be duly executed by their respective officers thereof duly authorized, as of the date first above written.

SPIRIT AIRLINES, INC.

By:
    Name:
    Title:

WILMINGTON TRUST, NATIONAL ASSOCIATION, not in its individual capacity, except as expressly provided herein, but solely as Loan Trustee

By:
    Name:
    Title:

Signature Page

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

SCHEDULE I
to First Indenture Amendment

DESCRIPTION OF EQUIPMENT NOTES

The information set forth below this text in this Schedule has been intentionally omitted from the FAA filing copy as the parties hereto deem it to contain confidential information.

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

SCHEDULE I
to First Indenture Amendment

DESCRIPTION OF EQUIPMENT NOTES



	Original Principal Amount	Maturity Date
Series A Equipment Notes:	$[●]	April 1, 2028
Series B Equipment Notes:	$[●]	April 1, 2024
Series C Equipment Notes:	$[●]	April 1, 2023

CERTAIN DEFINED TERMS

Defined Term Definition

Debt Rate for Series A Equipment Notes 4.100% per annum

Make-Whole Spread for Series A Equipment Notes 0.30%

Debt Rate for Series B Equipment Notes 4.450% per annum

Make-Whole Spread for Series B Equipment Notes 0.50%

Debt Rate for Series C Equipment Notes [●]% per annum

Make-Whole Spread for Series C Equipment Notes 0.[50]%

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

SCHEDULE I
to First Indenture Amendment (Cont’d)

EQUIPMENT NOTES AMORTIZATION

SERIES A EQUIPMENT NOTES

Airbus model [●]

[Reg. No.]



Payment Date	Percentage of Original Principal Amount to be Paid

SERIES B EQUIPMENT NOTES

Airbus model [●]

[Reg. No.]



Payment Date	Percentage of Original Principal Amount to be Paid

SERIES C EQUIPMENT NOTES

Airbus model [●]

[Reg. No.]

The principal amount of each Series C Equipment Note will be payable in a single payment on the Maturity Date for the Series C Equipment Note set forth on the first page of this Schedule I.

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

SCHEDULE I
to First Indenture Amendment (Cont’d)

EQUIPMENT NOTES AMORTIZATION

The portion of this Schedule appearing below this text is intentionally deleted from the FAA filing counterpart because the parties hereto deem it to contain confidential information.

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.4

SCHEDULE II
to First Indenture Amendment

PASS THROUGH TRUST AGREEMENT AND

PASS THROUGH TRUST SUPPLEMENTS

Pass Through Trust Agreement, dated as of August 11, 2015, between Spirit Airlines, Inc. and Wilmington Trust, National Association, as trustee, as supplemented by Trust Supplement No. 2015-1A, dated as of the Original Issuance Date.

First Amendment to

Indenture and Security Agreement (Spirit 2015-1 EETC)

[Reg. No.]

Exhibit 4.5

EXECUTION VERSION

AMENDED AND RESTATED

INTERCREDITOR AGREEMENT

(2017-1)

Dated as of May 10, 2018

among

WILMINGTON TRUST, NATIONAL ASSOCIATION

as Trustee of the

Spirit Airlines Pass Through Trust 2017-1AA,

Spirit Airlines Pass Through Trust 2017-1A,

Spirit Airlines Pass Through Trust 2017-1B,

and

Spirit Airlines Pass Through Trust 2017-1C

COMMONWEALTH BANK OF AUSTRALIA, NEW YORK BRANCH

as Class AA Liquidity Provider,

Class A Liquidity Provider

and

Class B Liquidity Provider,

and

WILMINGTON TRUST, NATIONAL ASSOCIATION

as Subordination Agent

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



AMERICAS 94409278

Exhibit 4.5

Table of Contents



Article I		Page
DEFINITIONS		2
Section 1.01	Definitions	2

Article II
TRUST ACCOUNTS; CONTROLLING PARTY
Section 2.01	Agreement to Terms of Subordination; Payments from Monies Received Only	23
Section 2.02	Trust Accounts	24
Section 2.03	Deposits to the Collection Account and Special Payments Account	25
Section 2.04	Distributions of Special Payments	25
Section 2.05	Designated Representatives	27
Section 2.06	Controlling Party	28

Article III
RECEIPT, DISTRIBUTION AND APPLICATION OF AMOUNTS RECEIVED
Section 3.01	Written Notice of Distribution	29
Section 3.02	Distribution of Amounts on Deposit in the Collection Account	31
Section 3.03	Other Payments	33
Section 3.04	Payments to the Trustees and the Liquidity Providers	34
Section 3.05	Liquidity Facilities	34

Article IV
EXERCISE OF REMEDIES
Section 4.01	Directions from the Controlling Party	42
Section 4.02	Remedies Cumulative	43
Section 4.03	Discontinuance of Proceedings	44
Section 4.04	Right of Certificateholders and the Liquidity Providers to Receive Payments Not to Be Impaired	44

Article V
DUTIES OF THE SUBORDINATION AGENT; AGREEMENTS OF TRUSTEES, ETC.
Section 5.01	Notice of Indenture Event of Default or Triggering Event	44
Section 5.02	Indemnification	45
Section 5.03	No Duties Except as Specified in Intercreditor Agreement	46
Section 5.04	Notice from the Liquidity Providers and Trustees	46

Article VI
THE SUBORDINATION AGENT
Section 6.01	Authorization; Acceptance of Trusts and Duties	46
Section 6.02	Absence of Duties	46

Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)

Exhibit 4.5

EXECUTION COPY



Section 6.03	No Representations or Warranties as to Documents	46
Section 6.04	No Segregation of Monies; No Interest	46
Section 6.05	Reliance; Agents; Advice of Counsel	47
Section 6.06	Capacity in Which Acting	47
Section 6.07	Compensation	47
Section 6.08	May Become Certificateholder	47
Section 6.09	Subordination Agent Required; Eligibility	47
Section 6.10	Money to Be Held in Trust	48
Section 6.11	Notice of Substitution or Replacement of Airframe.	48

Article VII
SUCCESSOR SUBORDINATION AGENT
Section 7.01	Replacement of Subordination Agent; Appointment of Successor	48

Article VIII
SUPPLEMENTS AND AMENDMENTS
Section 8.01	Amendments, Waivers, Etc	49
Section 8.02	Subordination Agent Protected	54
Section 8.03	Effect of Supplemental Agreements	54
Section 8.04	Notice to Rating Agencies	54

Article IX
MISCELLANEOUS
Section 9.01	Termination of Intercreditor Agreement	54
Section 9.02	Intercreditor Agreement for Benefit of Trustees, Liquidity Providers and Subordination Agent	54
Section 9.03	Notices	55
Section 9.04	Severability	56
Section 9.05	No Oral Modifications or Continuing Waivers	56
Section 9.06	Successors and Assigns	56
Section 9.07	Headings	56
Section 9.08	Counterparts	56
Section 9.09	Subordination	56
Section 9.10	Governing Law	57
Section 9.11	Submission to Jurisdiction; Waiver of Jury Trial; Waiver of Immunity	57
Section 9.12	Non-Petition	58
Section 9.13	Acknowledgement; Direction; Amendment and Restatement	58

Amended and Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



AMERICAS 94409278

Exhibit 4.5

AMENDED AND RESTATED INTERCREDITOR AGREEMENT

This AMENDED AND RESTATED INTERCREDITOR AGREEMENT, dated as of May 10, 2018, is made by and among WILMINGTON TRUST, NATIONAL ASSOCIATION, a national banking association (in its individual capacity, together with its successors and permitted assigns, “ WTNA ”), not in its individual capacity but solely as trustee of each Trust (such term and other capitalized terms used herein without definition being defined as provided in Article I); COMMONWEALTH BANK OF AUSTRALIA, NEW YORK BRANCH (“ CBA ”), as Class AA Liquidity Provider, Class A Liquidity Provider and Class B Liquidity Provider, and WILMINGTON TRUST, NATIONAL ASSOCIATION, not in its individual capacity except as expressly set forth herein, but solely as Subordination Agent and trustee hereunder (in such capacity, together with any successor appointed pursuant to Article VII, the “ Subordination Agent ”).

WHEREAS, the Class AA Trustee, the Class A Trustee, the Class B Trustee, the Class AA Liquidity Provider, the Class A Liquidity Provider, the Class B Liquidity Provider and the Subordination Agent entered into that certain Intercreditor Agreement (2017-1), dated as of November 28, 2017 (the “ Original Intercreditor Agreement ”);

WHEREAS, Spirit has a right to issue one or more series of “Additional Series Equipment Notes” (as defined in the Original Note Purchase Agreement) pursuant to the terms of Section 2.02 of each Indenture (in the case of any Funded Aircraft), Section 4(a)(v) of the Original Note Purchase Agreement and Section 8.01(d) of the Original Intercreditor Agreement, and such Section 8.01(d) provides that the Original Intercreditor Agreement shall be amended by written agreement of Spirit and the Subordination Agent to give effect to the issuance of any such “Additional Series Pass Through Certificates” (as defined in the Original Note Purchase Agreement) and the addition of the related “Additional Series Pass Through Trustee” (as defined in the Original Note Purchase Agreement) as a party to the Original Intercreditor Agreement;

WHEREAS, (i) pursuant to the Indenture with respect to each Funded Aircraft, Spirit has issued a Series AA Equipment Note, a Series A Equipment Note and a Series B Equipment Note and will issue a Series C Equipment Note on the date hereof and (ii) pursuant to the Indenture with respect to each

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	1

Exhibit 4.5

Pre‑Funded Aircraft, Spirit will issue a Series AA Equipment Note, a Series A Equipment Note, a Series B Equipment Note and a Series C Equipment Note, in each case, secured by, among other things, such Aircraft;

WHEREAS, (i) pursuant to the Participation Agreement with respect to each Funded Aircraft, the Class AA Trust, the Class A Trust and the Class B Trust have acquired the related Series AA Equipment Note, the related Series A Equipment Note and the related Series B Equipment Note and the Class C Trust will acquire the related Series C Equipment Note on the date hereof and (ii) pursuant to the Participation Agreement with respect to each Pre‑Funded Aircraft, each Trust will acquire Equipment Notes having an interest rate identical to the interest rate applicable to the Certificates issued by such Trust;

WHEREAS, the Liquidity Provider has entered into three separate revolving credit agreements on November 28. 2017 with the Subordination Agent, as agent and trustee for the Trustee of each of the Class AA Trust, the Class A Trust and the Class B Trust, respectively, for the benefit of the Certificateholders of such Trust; and

ARTICLE I

DEFINITIONS

Section 1.01 Definitions . (a) The definitions stated herein apply equally to the singular and the plural forms of the terms defined.

(b) All references in this Agreement to designated “Articles”, “Sections” and other subdivisions are to the designated Articles, Sections and other subdivisions of this Agreement.

(c) The words “herein”, “hereof” and “hereunder” and other words of similar import refer to this Agreement as a whole and not to any particular Article, Section or other subdivision.

(e) All references in this Agreement to a Person shall include successors and permitted assigns of such Person.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	2

Exhibit 4.5

(f) For purposes of this Agreement, unless the context otherwise requires, the following capitalized terms shall have the following meanings:

“ 60-Day Period ” means the 60-day period specified in Section 1110(a)(2)(A) of the Bankruptcy Code.

“ Additional Certificateholder ” has the meaning specified in Section 8.01(d), provided , however , that for the purposes of each Trust Supplement referenced in the definitions of “Class AA Trust Agreement”, “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Class C Certificateholder.

“ Additional Certificates ” has the meaning specified in Section 8.01(d), provided , however , that for the purposes of each Trust Supplement referenced in the definitions of “Class AA Trust Agreement”, “Class A Trust Agreement” and “Class B Trust Agreement” and each Liquidity Facility, such term shall include the Class C Certificates.

“ Additional Equipment Notes ” has the meaning specified in Section 8.01(d), provided , however , that for the purposes of each Trust Supplement referenced in the definitions of “Class AA Trust Agreement”, “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Series C Equipment Notes.

“ Additional Trust ” has the meaning specified in Section 8.01(d), provided , however , that for the purposes of each Trust Supplement referenced in the definitions of “Class AA Trust Agreement”, “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Class C Trust.

“ Additional Trust Agreement ” has the meaning specified in Section 8.01(d), provided , however , that for the purposes of each Trust Supplement referenced in the definitions of “Class AA Trust Agreement”, “Class A Trust Agreement” and “Class B Trust Agreement”, such term shall include the Class C Trust Agreement.

“ Additional Trustee ” has the meaning specified in Section 8.01(d).

“ Administration Expenses ” has the meaning specified in clause “first” of Section 3.02.

“ Advance ” means, with respect to any Liquidity Facility, any Advance as defined in such Liquidity Facility.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	3

Exhibit 4.5

“ Agreement ” means this Amended and Restated Intercreditor Agreement, as it may be amended, supplemented or otherwise modified from time to time.

“ Aircraft ” means, with respect to each Indenture, the “Aircraft” referred to therein.

“ Appraisal ” has the meaning specified in Section 4.01(a)(iv).

“ Appraised Current Market Value ” of any Aircraft means the lower of the average and the median of the three most recent Post-Default Appraisals of such Aircraft.

“ Bankruptcy Code ” means the United States Bankruptcy Code, 11 United States Code §§101 et seq. , as amended, or any successor statutes thereto.

“ Cash Collateral Account ” means the Class AA Cash Collateral Account, the Class A Cash Collateral Account or the Class B Cash Collateral Account, as applicable.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	4

Exhibit 4.5

“ CBA ” has the meaning specified in the introductory paragraph to this Agreement.

“ Certificate ” means a Class AA Certificate, a Class A Certificate, a Class B Certificate or a Class C Certificate, as applicable.

“ Certificateholder ” means, with respect to any Class of Certificates, the Person in whose name a Certificate is registered in the Register for the Certificates of such Class.

“ Class ” means a single class of Certificates issued by a Trust pursuant to a Trust Agreement.

“ Class AA Cash Collateral Account ” means, in respect of the Class AA Liquidity Facility, an Eligible Deposit Account in the name of the Subordination Agent maintained at an Eligible Institution, which shall be the Subordination Agent if it so qualifies, into which amounts shall be deposited as referred to in Section 3.05(f).

“ Class AA Certificateholder ” means, at any time, any Certificateholder of one or more Class AA Certificates.

“ Class AA Certificates ” means the certificates issued by the Class AA Trust, substantially in the form of Exhibit A to the Class AA Trust Agreement, and authenticated by the Class AA Trustee, representing Fractional Undivided Interests in the Class AA Trust, and any certificates issued in exchange therefor or replacement thereof pursuant to the terms of the Class AA Trust Agreement.

“ Class AA Liquidity Expenses ” means all Class AA Liquidity Obligations other than (i) the principal amount of any Drawings under the Class AA Liquidity Facility and (ii) any interest accrued on any Class AA Liquidity Obligations.

“ Class AA Liquidity Facility ” means, initially, the Revolving Credit Agreement (2017-1AA), dated as of November 28, 2017, between the Subordination Agent, as agent and trustee for the

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	5

Exhibit 4.5

Class AA Trustee, and CBA and, from and after the replacement of such agreement pursuant hereto, the Replacement Liquidity Facility therefor, if any, in each case as amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligation of Spirit, no amendment, modification or supplement to, or substitution or replacement of, any Class AA Liquidity Facility shall be effective unless consented to by Spirit.

“ Class AA Liquidity Obligations ” means all principal, interest, fees and other amounts owing to the Class AA Liquidity Provider under the Class AA Liquidity Facility, Section 4.02 of the Participation Agreements or the applicable Fee Letter.

“ Class AA Liquidity Provider ” means CBA, together with any Replacement Liquidity Provider that has issued a Replacement Liquidity Facility to replace the Class AA Liquidity Facility pursuant to Section 3.05(c) or 3.05(e).

“ Class AA Trust ” means the Spirit Airlines Pass Through Trust 2017-1AA created and administered pursuant to the Class AA Trust Agreement.

“ Class AA Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2017-1AA thereto, dated as of November 28, 2017, governing the creation and administration of the Spirit Airlines Pass Through Trust 2017-1AA and the issuance of the Class AA Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Class AA Trustee ” means WTNA, not in its individual capacity except as expressly set forth in the Class AA Trust Agreement, but solely as trustee under the Class AA Trust Agreement, together with any successor trustee appointed pursuant thereto.

“ Class A Adjusted Interest ” means, as of any Current Distribution Date: (I) any interest described in clause (II) of this definition accrued prior to the immediately preceding Distribution Date which remains unpaid and (II) the sum of (A) interest determined at the Stated Interest Rate for the Class A Certificates for the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Closing Date) and ending on, but excluding, the Current Distribution Date, on the Eligible A Pool Balance on such Current Distribution Date and (B) the sum of interest for each Series A Equipment Note with respect to which, or with respect to the Aircraft with respect to which such Equipment Note was issued, a disposition, distribution, sale or Deemed Disposition Event has occurred since the immediately preceding Distribution Date (but only if no such event has previously occurred with respect to such Series A Equipment Note), determined at the Stated Interest Rate for the Class A Certificates for each day during the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Closing Date) and ending on, but excluding, the date of the earliest of such disposition, distribution, sale or Deemed Disposition Event with respect to such Series A Equipment Note or such Aircraft, as the case may be, on the principal amount of such Series A Equipment Note calculated pursuant to clause (B)(i), (ii), (iii) or (iv), as applicable, of the definition of Eligible A Pool Balance.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	6

Exhibit 4.5

“ Class A Certificateholder ” means, at any time, any Certificateholder of one or more Class A Certificates.

“ Class A Liquidity Facility ” means, initially, the Revolving Credit Agreement (2017-1A), dated as of November 28, 2017, between the Subordination Agent, as agent and trustee for the Class A Trustee, and CBA and, from and after the replacement of such agreement pursuant hereto, the Replacement Liquidity Facility therefor, if any, in each case as amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligation of Spirit, no amendment, modification or supplement to, or substitution or replacement of, any Class A Liquidity Facility shall be effective unless consented to by Spirit.

“ Class A Liquidity Provider ” means CBA, together with any Replacement Liquidity Provider that has issued a Replacement Liquidity Facility to replace the Class A Liquidity Facility pursuant to Section 3.05(c) or 3.05(e).

“ Class A Trust ” means the Spirit Airlines Pass Through Trust 2017-1A created and administered pursuant to the Class A Trust Agreement.

“ Class A Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2017-1A thereto, dated as of November 28, 2017, governing the creation and administration of the Spirit Airlines Pass Through Trust 2017-1A and the issuance of the Class A Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	7

Exhibit 4.5

remains unpaid and (II) the sum of (A) interest determined at the Stated Interest Rate for the Class B Certificates for the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Closing Date) and ending on, but excluding, the Current Distribution Date, on the Eligible B Pool Balance on such Current Distribution Date and (B) the sum of interest for each Series B Equipment Note with respect to which, or with respect to the Aircraft with respect to which such Equipment Note was issued, a disposition, distribution, sale or Deemed Disposition Event has occurred since the immediately preceding Distribution Date (but only if no such event has previously occurred with respect to such Series B Equipment Note), determined at the Stated Interest Rate for the Class B Certificates for each day during the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Closing Date) and ending on, but excluding, the date of the earliest of such disposition, distribution, sale or Deemed Disposition Event with respect to such Series B Equipment Note or such Aircraft, as the case may be, on the principal amount of such Series B Equipment Note calculated pursuant to clause (B)(i), (ii), (iii) or (iv), as applicable, of the definition of Eligible B Pool Balance.

“ Class B Certificateholder ” means, at any time, any Certificateholder of one or more Class B Certificates.

“ Class B Liquidity Facility ” means, initially, the Revolving Credit Agreement (2017-1B), dated as of November 28, 2017, between the Subordination Agent, as agent and trustee for the Class B Trustee, and CBA and, from and after the replacement of such agreement pursuant hereto, the Replacement Liquidity Facility therefor, if any, in each case as amended, supplemented or otherwise modified from time to time in accordance with its terms; provided that, for purposes of any obligation of Spirit, no amendment, modification or supplement to, or substitution or replacement of, any Class B Liquidity Facility shall be effective unless consented to by Spirit.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	8

Exhibit 4.5

“ Class B Liquidity Provider ” means CBA, together with any Replacement Liquidity Provider that has issued a Replacement Liquidity Facility to replace the Class B Liquidity Facility pursuant to Section 3.05(c) or 3.05(e).

“ Class B Trust ” means the Spirit Airlines Pass Through Trust 2017-1B created and administered pursuant to the Class B Trust Agreement.

“ Class B Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2017-1B thereto, dated as of November 28, 2017, governing the creation and administration of the Spirit Airlines Pass Through Trust 2017-1B and the issuance of the Class B Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Class C Adjusted Interest ” means, as of any Current Distribution Date: (I) any interest described in clause (II) of this definition accrued prior to the immediately preceding Distribution Date which remains unpaid and (II) the sum of (A) interest determined at the Stated Interest Rate for the Class C Certificates for the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Class C Closing Date) and ending on, but excluding, the Current Distribution Date, on the Eligible C Pool Balance on such Current Distribution Date and (B) the sum of interest for each Series C Equipment Note with respect to which, or with respect to the Aircraft with respect to which such Equipment Note was issued, a disposition, distribution, sale or Deemed Disposition Event has occurred since the immediately preceding Distribution Date (but only if no such event has previously occurred with respect to such Series C Equipment Note), determined at the Stated Interest Rate for the Class C Certificates for each day during the period commencing on, and including, the immediately preceding Distribution Date (or, if the Current Distribution Date is the first Distribution Date, the Class C Closing Date) and ending on, but excluding, the date of the earliest of such disposition, distribution, sale or Deemed Disposition Event with respect to such Series C Equipment Note or such Aircraft, as the case may be, on the principal amount of such Series C Equipment Note calculated pursuant to clause (B)(i), (ii), (iii) or (iv), as applicable, of the definition of Eligible C Pool Balance.

“ Class C Certificateholder ” means, at any time, any Certificateholder of one or more Class C Certificates.

“ Class C Closing Date ” means May 10, 2018.

“ Class C Trust ” means the Spirit Airlines Pass Through Trust 2017-1C created and administered pursuant to the Class C Trust Agreement.

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	9

Exhibit 4.5

“ Class C Trust Agreement ” means the Basic Agreement, as supplemented by Trust Supplement No. 2017-1C thereto, dated as of the date hereof, governing the creation and administration of the Spirit Airlines Pass Through Trust 2017-1C and the issuance of the Class C Certificates, as the same may be amended, supplemented or otherwise modified from time to time in accordance with its terms.

“ Closing Date ” means November 28, 2017.

“ Code ” means the Internal Revenue Code of 1986, as amended from time to time, and Treasury Regulations promulgated thereunder.

“ Collateral ” means, with respect to any Indenture, the “Collateral” referred to therein.

“ Combination Replacement Liquidity Facility ” has the meaning set forth in the definition of “Replacement Liquidity Facility”.

“ Consent Notice ” has the meaning set forth in Section 3.05(d)(ii).

“ Consent Period ” has the meaning set forth in Section 3.05(d)(ii).

“ Controlling Party ” means the Person entitled to act as such pursuant to the terms of Section 2.06.

“ Delivery Period Termination Date ” has the meaning specified in the Note Purchase Agreement.

“ Deposit Agreement ” means, subject to Section 5 of the Note Purchase Agreement, (i) with respect to any Class of Certificates (other than the Class C Certificates), the Deposit Agreement pertaining

Amended and Restated Intercreditor Agreement (2017-1)
(Spirit 2017-1 EETC)



	10

Exhibit 4.5

to such Class, dated as of November 28, 2017 between the Escrow Agent and the Depositary and (ii) with respect to the Class C Certificates, the Deposit Agreement dated as of the date hereof between the Escrow Agent and the Depositary, in each case as the same may be amended, modified or supplemented from time to time in accordance with the terms thereof.

“ Depositary ” means, subject to Section 5 of the Note Purchase Agreement, Citibank, N.A., as depositary under each Deposit Agreement.

“ Deposits ”, with respect to any Class of Certificates, has the meaning set forth in the Deposit Agreement pertaining to such Class.