UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
_______________________________________________________________________

Form 10-Q

(Mark One)
ýQUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934
For the quarterly period ended SeptemberJune 30, 20172018
OR
oTRANSITION 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)

Delaware38-1747023
(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 filerýAccelerated filero
Non-accelerated fileroSmaller reporting companyo
(Do not check if a smaller reporting company)Emerging growth companyo
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 OctoberJuly 19, 2017:2018:
Class Number of Shares
Common Stock, $0.0001 par value 69,373,15468,252,441






Table of Contents
INDEX
 
 Page No.
 
  
   
   
   
   
   
  
   
  
  
 
  
  
  
  
  
  
  






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 September 30, Nine Months Ended September 30,Three Months Ended June 30, Six Months Ended June 30,
2017 2016 2017 20162018 2017 2018 2017
Operating revenues:              
Passenger$356,207
 $331,004
 $1,027,891
 $900,031
$836,350
 $680,880
 $1,525,491
 $1,253,167
Non-ticket331,024
 290,325
 952,768
 843,574
Other15,421
 19,305
 30,418
 36,975
Total operating revenues687,231
 621,329
 1,980,659
 1,743,605
851,771
 700,185
 1,555,909
 1,290,142
              
Operating expenses:              
Aircraft fuel246,180
 142,294
 450,826
 282,076
Salaries, wages and benefits134,114
 120,190
 391,144
 349,530
187,756
 129,892
 342,852
 257,030
Aircraft fuel158,300
 121,844
 440,376
 321,018
Aircraft rent53,396
 49,367
 163,032
 151,433
41,745
 52,566
 91,936
 109,636
Landing fees and other rents48,498
 39,345
 134,538
 114,096
58,602
 45,592
 108,232
 86,040
Depreciation and amortization36,840
 25,304
 103,680
 73,370
45,618
 35,331
 84,991
 66,840
Maintenance, materials and repairs26,176
 30,443
 81,473
 72,010
31,653
 28,985
 61,363
 55,297
Distribution29,469
 25,565
 85,875
 73,190
34,997
 29,835
 65,628
 55,607
Special charges7,853
 7,355
 12,629
 31,609
174
 
 89,342
 4,776
Loss on disposal of assets516
 423
 3,114
 1,166
4,644
 1,493
 5,492
 2,598
Other operating87,965
 66,277
 268,553
 197,833
91,881
 102,885
 185,523
 180,588
Total operating expenses583,127
 486,113
 1,684,414
 1,385,255
743,250
 568,873
 1,486,185
 1,100,488
              
Operating income104,104
 135,216
 296,245
 358,350
108,521
 131,312
 69,724
 189,654
              
Other (income) expense:              
Interest expense15,018
 11,362
 41,237
 29,588
20,498
 13,746
 38,347
 26,219
Capitalized interest(3,203) (3,067) (10,125) (9,163)(2,296) (3,342) (4,548) (6,922)
Interest income(2,605) (1,222) (5,746) (4,235)(4,430) (1,828) (8,496) (3,141)
Other expense114
 180
 221
 407
188
 104
 321
 107
Special charges, non-operating79,412
 
 88,613


Total other (income) expense9,324
 7,253
 25,587
 16,597
93,372
 8,680
 114,237
 16,263
              
Income before income taxes94,780
 127,963
 270,658
 341,753
Provision for income taxes34,590
 46,581
 100,390
 125,367
Income (loss) before income taxes15,149
 122,632
 (44,513) 173,391
Provision (benefit) for income taxes3,895
 45,391
 (10,845) 64,889
              
Net income$60,190
 $81,382
 $170,268
 $216,386
Basic earnings per share$0.87
 $1.17
 $2.45
 $3.06
Diluted earnings per share$0.87
 $1.17
 $2.45
 $3.05
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 Statements of Comprehensive Income
(unaudited, in thousands)

 Three Months Ended September 30, Nine Months Ended September 30,
 2017 2016 2017 2016
Net income$60,190
 $81,382
 $170,268
 $216,386
Unrealized gain (loss) on short-term investment securities, net of deferred taxes of $7, $3, ($6) and $313
 4
 (11) 4
Interest rate derivative losses reclassified into earnings, net of taxes of $31, $32, $92 and $97
53
 56
 160
 170
Other comprehensive income (loss)$66
 $60
 $149
 $174
Comprehensive income$60,256
 $81,442
 $170,417
 $216,560

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




Spirit Airlines, Inc.
Condensed Balance Sheets
(unaudited, in thousands)
 
September 30, 2017 December 31, 2016June 30, 2018 December 31, 2017
Assets      
Current assets:      
Cash and cash equivalents$863,680
 $700,900
$812,362
 $800,849
Short-term investment securities100,732

100,155
101,714
 100,937
Accounts receivable, net46,235
 41,136
58,547
 49,323
Aircraft maintenance deposits, net166,386

87,035
107,252
 175,615
Income tax receivable70,672
 69,844
Prepaid expenses and other current assets67,707
 46,619
79,788
 85,542
Total current assets1,244,740
 975,845
1,230,335
 1,282,110
      
Property and equipment:      
Flight equipment2,017,888
 1,461,525
2,911,378
 2,291,110
Ground property and equipment148,324
 126,206
168,039
 155,166
Less accumulated depreciation(183,065) (122,509)(261,314) (207,808)
1,983,147
 1,465,222
2,818,103
 2,238,468
Deposits on flight equipment purchase contracts304,732
 325,688
240,224
 253,687
Long-term aircraft maintenance deposits138,672
 199,415
141,183
 150,617
Deferred heavy maintenance, net87,566
 75,534
172,799
 99,915
Other long-term assets112,085
 110,223
79,081
 121,003
Total assets$3,870,942
 $3,151,927
$4,681,725
 $4,145,800
      
Liabilities and shareholders’ equity      
Current liabilities:      
Accounts payable$30,961
 $15,193
$50,310
 $22,822
Air traffic liability276,933
 206,392
357,645
 263,711
Current maturities of long-term debt105,958
 84,354
Current maturities of long-term debt and capital leases145,865
 115,430
Other current liabilities249,132
 226,011
346,407
 262,370
Total current liabilities662,984
 531,950
900,227
 664,333
      
Long-term debt, less current maturities1,214,138
 897,359
1,731,766
 1,387,498
Deferred income taxes406,080
 308,143
295,601
 308,814
Deferred gains and other long-term liabilities17,204
 19,868
20,630
 22,581
Shareholders’ equity:      
Common stock
7
 7
7
 7
Additional paid-in-capital557,772
 551,004
365,536
 360,153
Treasury stock, at cost(219,930) (218,692)(66,840) (65,854)
Retained earnings1,233,901
 1,063,633
1,436,064
 1,469,732
Accumulated other comprehensive loss(1,214) (1,345)
Accumulated other comprehensive income (loss)(1,266) (1,464)
Total shareholders’ equity1,570,536
 1,394,607
1,733,501
 1,762,574
Total liabilities and shareholders’ equity$3,870,942
 $3,151,927
$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)
Nine Months Ended September 30,Six Months Ended June 30,
2017 20162018 2017
Operating activities:
 

 
Net income$170,268
 $216,386
Adjustments to reconcile net income to net cash provided by operations:
 
Net income (loss)$(33,668) $108,502
Adjustments to reconcile net income (loss) to net cash provided by operations:
 
Losses reclassified from other comprehensive income252

267
159

167
Equity-based compensation6,723
 5,503
Stock-based compensation5,381
 4,671
Allowance for doubtful accounts (recoveries)(53) 213
(12) (51)
Amortization of deferred gains and losses and debt issuance costs6,415
 3,837
4,552
 4,761
Depreciation and amortization103,680
 73,370
84,991
 66,840
Deferred income tax expense97,834
 77,627
Deferred income tax expense (benefit)(17,604) 64,789
Loss on disposal of assets3,114
 1,166
5,492
 2,598
Lease termination costs12,629

31,609


4,776
Special charges, non-operating88,613
 



 



 

Changes in operating assets and liabilities:

 



  
Accounts receivable(5,046) (7,840)(9,212) (6,808)
Aircraft maintenance deposits, net(28,422) (38,299)11,222
 (17,940)
Prepaid income taxes(160)
66,218


(1,598)
Long-term deposits and other assets(81,622) (43,252)3,003
 (17,507)
Deferred heavy maintenance(94,267) (28,191)
Income tax receivable(828) 
Accounts payable13,829
 (7,044)25,413
 16,387
Air traffic liability70,540
 21,963
93,936
 108,574
Other liabilities16,152
 38,317
83,809
 13,518
Other339
 
8
 239
Net cash provided by operating activities386,472
 440,041
250,988
 323,727
Investing activities:      
Purchase of available-for-sale investment securities(96,851)
(100,076)(73,687)
(68,459)
Proceeds from the maturity of available-for-sale investment securities95,881


72,964

67,857
Proceeds from sale of property and equipment
 50
9,500
 
Pre-delivery deposits for flight equipment, net of refunds(121,702) (109,260)(92,205) (79,357)
Capitalized interest(8,054)
(7,032)(4,178)
(6,375)
Purchase of property and equipment(428,061) (447,455)(323,229) (269,519)
Net cash used in investing activities(558,787) (663,773)(410,835) (355,853)
Financing activities:      
Proceeds from issuance of long-term debt405,827

378,569
440,340

255,827
Proceeds from stock options exercised45
 92
2
 29
Payments on debt and capital lease obligations(63,643) (29,663)
Excess tax (deficiency) benefit from equity-based compensation
 (497)
Payments on debt obligations(60,649) (49,980)
Payments on capital lease obligations(205,403) (119)
Repurchase of common stock(1,238) (102,390)(986) (1,217)
Debt issuance costs(5,896)
(107)(1,944)
(4,164)
Net cash provided by financing activities335,095
 246,004
171,360
 200,376
Net (decrease) increase in cash and cash equivalents162,780
 22,272
11,513
 168,250
Cash and cash equivalents at beginning of period700,900
 803,632
800,849
 700,900
Cash and cash equivalents at end of period$863,680
 $825,904
$812,362
 $869,150
Supplemental disclosures      
Cash payments for:      
Interest, net of capitalized interest$22,541
 $26,025
$16,769
 $16,869
Income taxes paid, net of refunds$4,352
 $(18,169)$3,270
 $4,340
Non-cash transactions:      
Capital expenditures funded by capital lease borrowings$(1,370)
$(31)$(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)("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)("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, 20162017 filed with the Securities and Exchange Commission on February 13, 2017.2018.
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.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)("the FASB") issued Accounting Standards Update (ASU)("ASU") No. 2014-09, (ASU 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 newCompany adopted this guidance is effective for the Company in the first quarter of 2018. Entities have the option to use either a full retrospective or a modified retrospective approach to adopt ASU 2014-09. The Company currently anticipateson 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, and plans to adopt the standard as of January 1, 2018. While the Company is still evaluating the impact, it currently believes thepresented. The most significant impact of this ASU will beis the elimination of the incremental cost method for frequent flier program accounting, which will requirerequires 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. While our evaluation is ongoing, the Company currently estimates that applying a relative fair value would increase its air traffic liability by approximately $10 million at the date of adoption. The Company also expects the classification and timing of recognition of certain ancillary fees to beis also impacted by the adoption of ASU 2014-09. While the Company believes the adoption willdid not have a significant impact on earnings, the classification of certain revenues, such as bags, seats and other travel-related fees may beare now deemed part of the single performance obligation of providing passenger transportation. The Company expects that theseRefer 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 currently classified as non-ticket revenue, approximately $1 billion annually, will be reclassified to passenger revenue after adoption.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 and is not expected to have awith no material impact on the Company’s financial statements.


LeasesStatement 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. SeeRefer to Note 8,10, Commitments and Contingencies for information regarding the Company's undiscounted future lease payments and the timing of those payments.

Share-Based Compensation

In March 2016, the FASB issued ASU No. 2016-09, "Improvements to Employee Share-Based Payment Accounting," which simplifies several aspects of the accounting for employee share-based payment transactions, including the accounting for income taxes, forfeitures, and statutory tax withholding requirements, as well as classification on the statement of cash flows. The Company adopted this guidance on January 1, 2017. As a result, excess income tax benefits and deficiencies related to share-based compensation are now included within income tax expense rather than additional paid in capital. For the nine months ended September 30, 2017, $0.6 million of income tax deficiency related to share-based compensation was included within income tax expense on the Company's statements of operations. Additionally, excess income tax benefits and deficiencies for share-based payments are now included in net operating cash flows rather than net financing cash flows. The changes have been applied prospectively in accordance with the guidance and prior periods have not been adjusted.


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.


Statement of Cash Flows

Income Taxes

In August 2016,March 2018, the FASB issued ASU 2018-05, Income Taxes ("Topic 740") - Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 2016-15, "Statement of Cash Flows."118. The standard is intendedamends Accounting Standards Codification 740, Income Taxes ("ASC 740") to reduce diversity in practice in how certain transactions are classified inprovide guidance on accounting for the statementtax effects of cash flows. This standard is effectivethe 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 for fiscal years, and interimmay change in future reporting periods within those years, beginning January 1, 2018, with early adoption permitted.until the accounting is finalized, which will occur no later than the fourth quarter of 2018. The Company is evaluating the new guidance, but does not expect itthe 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.
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
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
Other1,281,632
 (1,210,967) 70,665
Total operating revenues2,647,666
 (4,114) 2,643,552
      
Operating expenses:     
Aircraft fuel615,581
 
 615,581
Salaries, wages and benefits
527,959
 
 527,959
Aircraft rent205,852
 
 205,852
Landing fees and other rents180,655
 
 180,655
Depreciation and amortization140,152
 
 140,152
Maintenance, materials and repairs110,439
 
 110,439
Distribution113,620
 (148) 113,472
Special charges12,629
 
 12,629
Loss on disposal of assets4,168
 
 4,168
Other operating347,820
 
 347,820
Total operating expenses2,258,875
 (148) 2,258,727
      
Operating income388,791
 (3,966) 384,825
      
Other (income) expense:     
Interest expense57,302
 
 57,302
Capitalized interest(13,793) 
 (13,793)
Interest income(8,736) 
 (8,736)
Other expense366
 
 366
Total other (income) expense35,139
 
 35,139
      
Income before income taxes353,652
 (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
Other1,121,335
 (1,059,115) 62,220
Total operating revenues2,321,956
 (1,935) 2,320,021
      
Operating expenses:     
Salaries, wages and benefits
472,471
 
 472,471
Aircraft fuel447,553
 
 447,553
Aircraft rent201,675
 
 201,675
Landing fees and other rents151,679
 
 151,679
Depreciation and amortization101,136
 
 101,136
Maintenance, materials and repairs98,587
 
 98,587
Distribution96,627
 268
 96,895
Special charges37,189
 
 37,189
Loss on disposal of assets4,187
 
 4,187
Other operating267,191
 
 267,191
Total operating expenses1,878,295
 268
 1,878,563
      
Operating income443,661
 (2,203) 441,458
      
Other (income) expense:     
Interest expense41,654
 
 41,654
Capitalized interest(12,705) 
 (12,705)
Interest income(5,276) 
 (5,276)
Other expense528
 
 528
Total other (income) expense24,201
 
 24,201
      
Income before income taxes419,460
 (2,203) 417,257
Provision (benefit) for income taxes154,581
 (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
Other17,670
 19,305
 18,155
 15,535
Total operating revenues589,957
 700,185
 687,227
 666,182
        
Operating expenses:       
Aircraft fuel139,782
 142,294
 158,300
 175,205
Salaries, wages and benefits
127,138
 129,892
 134,114
 136,815
Aircraft rent57,070
 52,566
 53,396
 42,820
Landing fees and other rents40,448
 45,592
 48,498
 46,117
Depreciation and amortization31,509
 35,331
 36,840
 36,472
Maintenance, materials and repairs26,312
 28,985
 26,176
 28,966
Distribution25,772
 29,835
 29,695
 28,170
Special charges4,776
 
 7,853
 
Loss on disposal of assets1,105
 1,493
 516
 1,054
Other operating77,703
 102,885
 87,965
 79,267
Total operating expenses531,615
 568,873
 583,353
 574,886
        
Operating income58,342
 131,312
 103,874
 91,296
        
Other (income) expense:       
Interest expense12,473
 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 expense3
 104
 114
 145
Total other (income) expense7,583
 8,680
 9,324
 9,552
        
Income before income taxes50,759
 122,632
 94,550
 81,744
Provision (benefit) for income taxes19,498
 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
Other1,281,632
 (274,314) (310,455) (312,869) (313,329) 70,665
Total operating revenues2,647,666
 (1,789) (1,496) (4) (825) 2,643,552
            
Operating expenses:           
Aircraft fuel615,581
 
 
 
 
 615,581
Salaries, wages and benefits
527,959
 
 
 
 
 527,959
Aircraft rent205,852
 
 
 
 
 205,852
Landing fees and other rents180,655
 
 
 
 
 180,655
Depreciation and amortization140,152
 
 
 
 
 140,152
Maintenance, materials and repairs110,439
 
 
 
 
 110,439
Distribution113,620
 (726) (73) 226
 425
 113,472
Special charges12,629
 
 
 
 
 12,629
Loss on disposal of assets4,168
 
 
 
 
 4,168
Other operating347,820
 
 
 
 
 347,820
Total operating expenses2,258,875
 (726) (73) 226
 425
 2,258,727
            
Operating income388,791
 (1,063) (1,423) (230) (1,250) 384,825
            
Other (income) expense:           
Interest expense57,302
 
 
 
 
 57,302
Capitalized interest(13,793) 
 
 
 
 (13,793)
Interest income(8,736) 
 
 
 
 (8,736)
Other expense366
 
 
 
 
 366
Total other (income) expense35,139
 
 
 
 
 35,139
            
Income before income taxes353,652
 (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 securities100,937
 
 100,937
Accounts receivable, net49,323
 
 49,323
Aircraft maintenance deposits, net175,615
 
 175,615
Income tax receivable69,844
 
 69,844
Prepaid expenses and other current assets83,692
 1,850
 85,542
Total current assets1,280,260
 1,850
 1,282,110
      
Property and equipment:     
Flight equipment2,291,110
 
 2,291,110
Ground property and equipment155,166
 
 155,166
Less accumulated depreciation(207,808) 
 (207,808)
 2,238,468
 
 2,238,468
Deposits on flight equipment purchase contracts253,687
 
 253,687
Long-term aircraft maintenance deposits150,617
 
 150,617
Deferred heavy maintenance, net99,915
 
 99,915
Other long-term assets121,003
 
 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 liability246,404
 17,307
 263,711
Current maturities of long-term debt115,430
 
 115,430
Other current liabilities262,370
 
 262,370
Total current liabilities647,026
 17,307
 664,333
      
Long-term debt, less current maturities1,387,498
 
 1,387,498
Deferred income taxes313,140
 (4,326) 308,814
Deferred gains and other long-term liabilities19,205
 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-capital360,153
 
 360,153
Treasury stock, at cost: 1,573,831 shares as of December 31, 2017
(65,854) 
 (65,854)
Retained earnings1,484,239
 (14,507) 1,469,732
Accumulated other comprehensive income (loss)(1,464) 
 (1,464)
Total shareholders’ equity1,777,081
 (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 securities100,155
 
 100,155
Accounts receivable, net41,136
 
 41,136
Aircraft maintenance deposits, net87,035
 
 87,035
Income tax receivable
 
 
Prepaid expenses and other current assets46,619
 1,702
 48,321
Total current assets975,845
 1,702
 977,547
      
Property and equipment:     
Flight equipment1,461,525
 
 1,461,525
Ground property and equipment126,206
 
 126,206
Less accumulated depreciation(122,509) 
 (122,509)
 1,465,222
 
 1,465,222
Deposits on flight equipment purchase contracts325,688
 
 325,688
Long-term aircraft maintenance deposits199,415
 
 199,415
Deferred heavy maintenance, net75,534
 
 75,534
Other long-term assets110,223
 
 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 liability206,392
 13,792
 220,184
Current maturities of long-term debt84,354
 
 84,354
Other current liabilities226,011
 
 226,011
Total current liabilities531,950
 13,792
 545,742
      
Long-term debt, less current maturities897,359
 
 897,359
Deferred income taxes308,143
 (5,443) 302,700
Deferred gains and other long-term liabilities19,868
 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-capital551,004
 
 551,004
Treasury stock, at cost: 4,223,670 shares as of December 31, 2016
(218,692) 
 (218,692)
Retained earnings1,063,633
 (9,423) 1,054,210
Accumulated other comprehensive income (loss)(1,345) 
 (1,345)
Total shareholders’ equity1,394,607
 (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-fare396,801
 346,446
 313,323
 313,479
 309,437
 273,252
Total passenger revenues836,350
 689,141
 650,647
 669,072
 680,880
 572,287
Other revenues15,421
 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 revenues1,366,034
 1,206,853
 2,572,887
 1,200,621
 1,057,180
 2,257,801
Other revenues1,281,632
 (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 America83.5
 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 threefirst 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 SeptemberJune 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 aircraftengine which was previously financed under an operating lease agreement. The purchase price of the aircraft was $20.0 million, comprised of a cash payment of $12.6 million and the non-cash application of maintenance and security deposits held by the previous lessor of $7.4 million. The Company estimated the fair value of the aircraft to be $11.9 million and has recorded the 1 purchased aircraft at fair value within flight equipment on the condensed balance sheets. The Company determined the valuation of the aircraft based on a third-party appraisal considering the condition of the aircraft (a Level 3 measurement). The Company recognized $7.9 million as a cost of terminating the lease within special charges on the condensed statement of operations, made up of the excess of the purchase price paid over the fair value of the aircraft, less other non-cash items of $0.2 million.

During the three months ended September 30, 2016, the Company purchased three A319 aircraft which were formerly financed under operating lease agreements. The purchase price for the 3 aircraft was $58.8 million, comprised of a cash payment of $58.1 million and the application of security deposits held by the previous lessor of $0.7 million. The Company estimated the fair value of the aircraft to be $38.2 million and has recorded the 3 purchased aircraft within flight equipment on the condensed balance sheets. The Company determined the valuation of the aircraft based on a third-party appraisal considering the condition of each aircraft (a Level 3 measurement). The Company recognized $7.4 million as a cost of terminating the leases within special charges on the condensed statement of operations, made up of the excess of the purchase price paid over the fair value of the aircraft, less previously expensed supplemental rent and other non-cash items of $13.2 million.

Notes to Condensed Financial Statements—(Continued)

During the nine months ended September 30, 2017, the Company purchased one engine and one aircraft which were previously financed under operating lease agreements. The purchase price of the 1 engine and 1 aircraft was $8.1 million, and $20.0 million, respectively, comprised of a cash payment of $3.8 million and $12.6 million, respectively, and the non-cash application of maintenance reserves and security deposits held by the previous lessor of $4.3 million and $7.4 million, respectively.million. The Company estimated the fair value of the engine and aircraft to be $3.1 million and $11.9 million, respectively, and has recorded the 1 purchased engine and 1 aircraft at fair value within flight equipment on the condensed balance sheets. The Company determined the valuation of the engine and aircraft based on a third-party appraisal considering the condition of the engine and aircraft (a Level 3 measurement). The Company recognized $4.8 million and $7.9 million as a cost of terminating the lease within special charges on the condensed statement of operations, respectively, made upcomprised of the excess of the purchase price paid over the fair value of the engine, and the aircraft, less other non-cash items of $0.2 million and $0.2 million, respectively.million.

Special Charges, Non-Operating

During the ninethree and six months ended SeptemberJune 30, 2016,2018, the Company purchased sixrecorded $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 which were previously financedoperated under operating lease agreements.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 6 aircraftsale was $124.7 million, comprised of a cash payment net of $91.9 million and the non-cash applicationamount of maintenance reserves and security deposits for such aircraft held by the previousapplicable lessor pursuant to the lease for such aircraft. The contract was deemed a lease modification which resulted in a change of $32.8 million. The Company estimatedclassification 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 to be $79.4 million and has recorded the 6 purchased aircraft at fair value 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 a third-party appraisalappraisals considering the condition of eachthe aircraft (a Level 3 measurement). The Company recognized $31.6 million as a cost of terminating the leases within special charges on the condensed statement of operations, made up of the excess of the purchase price paid over the fair value of the aircraft, less other non-cash items of $13.7 million.


4.6.Earnings per Share
The following table sets forth the computation of basic and diluted earnings (loss) per common share:
 Three Months Ended September 30, Nine Months Ended September 30,
 2017 2016 2017 2016
 (in thousands, except per share amounts)
Numerator       
Net income$60,190
 $81,382
 $170,268
 $216,386
Denominator       
Weighted-average shares outstanding, basic69,370
 69,727
 69,363
 70,689
Effect of dilutive stock awards88
 81
 174
 143
Adjusted weighted-average shares outstanding, diluted69,458
 69,808
 69,537
 70,832
Net income per share       
Basic earnings per common share$0.87
 $1.17
 $2.45
 $3.06
Diluted earnings per common share$0.87
 $1.17
 $2.45
 $3.05
        
Anti-dilutive weighted-average shares124

122
 76
 87


 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, basic68,251
 69,370
 68,237
 69,359
Effect of dilutive stock awards59
 191
 
 217
Adjusted weighted-average shares outstanding, diluted68,310
 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 shares248

17
 264
 52

Notes to Condensed Financial Statements—(Continued)


5.7.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. Unrealized gains and losses on investment securities are reflected as a component of accumulated other comprehensive income (AOCI).


As of SeptemberJune 30, 20172018 and December 31, 2016,2017, the Company had $100.7$101.7 million and $100.2$100.9 million in short-term available-for-sale investment securities, respectively. During the ninesix months ended SeptemberJune 30, 2017,2018, these investments earned interest income at a weighted-average fixed rate of approximately 1.5%1.4%. For the three and ninesix months ended SeptemberJune 30, 2017,2018, an unrealized gain of $13$101 thousand and an unrealized lossgain of $11$78 thousand, net of deferred taxes of $7$33 thousand and $6$26 thousand, respectively, was recorded within AOCIaccumulated other comprehensive income/(loss) ("AOCI") related to these investment securities. For the three and ninesix months ended SeptemberJune 30, 2016,2017, an unrealized gainloss of $4$11 thousand and $24 thousand, net of deferred taxes of $3$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 SeptemberJune 30, 20172018 and December 31, 2016, $342017, $27 thousand and $23$105 thousand, net of tax, respectively, remained in AOCI, related to these instruments.


6.8.Accrued Liabilities
Other current liabilities as of SeptemberJune 30, 20172018 and December 31, 20162017 consist of the following:
 September 30, 2017 December 31, 2016
 (in thousands)
Salaries and wages$50,635
 $54,578
Airport obligations47,289
 43,989
Federal excise and other passenger taxes and fees payable43,860
 42,064
Aircraft maintenance41,781
 30,233
Interest payable15,168
 8,499
Fuel14,940
 14,828
Aircraft and facility lease obligations11,678
 10,378
Other23,781
 21,442
Other current liabilities$249,132
 $226,011


 June 30, 2018 December 31, 2017
 (in thousands)
Federal excise and other passenger taxes and fees payable$78,393
 $42,036
Salaries and wages77,363
 54,338
Airport obligations59,981
 56,299
Aircraft maintenance44,065
 33,033
Fuel24,543
 25,171
Interest payable19,620
 11,384
Aircraft and facility lease obligations14,020
 16,992
Other28,422
 23,117
Other current liabilities$346,407
 $262,370



7.9.Financial Instruments and Risk Management
As part of the Company’s risk management program, the Company from time to time may useuses 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. As of September 30, 2017, the Company did not hold any derivatives with requirements to post collateral. 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. Historically, theThe Company's fuel derivative contracts, haveif any, generally consistedconsist of United States Gulf Coast jet fuel swaps (jet("jet fuel swaps)swaps") and United States Gulf Coast jet fuel options (jet("jet fuel options)options"). Both jet fuel swaps and jet fuel options have beenare 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 suchthe instruments is determined using standard option valuation models.

Notes to Condensed Financial Statements—(Continued)


The Company accounts for itsany fuel derivative contracts at fair value and recognizes them in the condensed 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 ninesix months ended SeptemberJune 30, 20172018 and 20162017 and did not have any outstanding fuel derivatives as of SeptemberJune 30, 20172018 and December 31, 2016.2017. 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
During 2015,From time to time, the Company settled six forwardmay enter into interest rate swaps that were designed to fix the benchmark interest rate component of interest payments on the debt related to three Airbus A321 aircraft, which the Company took delivery of during the third quarter of 2015.or for other reasons. These instruments limitedlimit the Company's exposure to changes in the benchmark interest rate in the period from the trade date through the date of maturity. The interestInterest rate swaps weremay be designated as cash flow hedges. The Company generally accounts for interest rate swaps at fair value and recognizes them in the condensed balance sheet in prepaid expenses and other current assets or other current liabilities with changes in fair value recorded within accumulated other comprehensive income (AOCI).AOCI. As of SeptemberJune 30, 20172018 and December 31, 2016,2017, the Company did not have any outstanding interest rate swaps.
Notes to Condensed Financial Statements—(Continued)

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 three and ninesix months ended SeptemberJune 30, 20172018 and 2016,2017, there were no unrealized gains or losses recorded within AOCI related to these instruments as they settled in 2015. For the three and ninesix months ended SeptemberJune 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 $160$107 thousand, net of tax of $31 thousand and $92 thousand, respectively, into earnings. For the three and nine months ended September 30, 2016, the Company reclassified interest rate swap losses of $56 thousand and $170 thousand, net of tax of $32 thousand and $97$62 thousand, respectively, into earnings. As of SeptemberJune 30, 20172018 and December 31, 2016,2017, $1.2 million and $1.3$1.4 million, net of tax, respectively, remained in AOCI, related to these instruments.


8.10.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 2017,2018, the Company negotiated revisions to its A320 aircraft order. The Company originally had four14 A320neo aircraft scheduled for delivery in 20182019. Pursuant to the revisions, 5 of which twothe 14 scheduled A320neo aircraft were converted to A320ceo aircraft and are scheduled to be delivered in 2017,2018 and the remaining two are deferred until 2019. As of SeptemberJune 30, 2017,2018, the Company's aircraft orders consisted of the following:
  Airbus 
  A320ceo A320neo A321ceo Total
remainder of 2017 2 
 4 6
2018 5 
 5 10
2019 1 14 
 15
2020 
 16 
 16
2021 
 18 
 18
  8 48 9 65


  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 fourtwo spare engine orders for V2500 SelectTwoengines with International Aero Engines (IAE)("IAE") and nine spare engine orders for PurePower PW1100G-JM engines with Pratt & Whitney. Spare engines are scheduled for delivery from 2018 through 2023.2023. Purchase commitments for these aircraft and spare engines, including estimated amounts for contractual price escalations and pre-delivery payments, are expected to be $227.8$345.6 million for the remainder of 2017, $528.4 million inremainder of 2018, $773.7$600.7 million in 2019, $820.5$821.6 million in 2020, $784.8$785.1 million in 2021, and $24.6$16.8 million in 2022, and $7.9 million in 2023 and beyond. As of SeptemberJune 30, 2017,2018, the Company had secured debt financing commitments of $160.0$117.0 million for 43 aircraft, scheduled for delivery in the remainder of 2017,2018, and did not have financing commitments in place for the remaining 6149 Airbus aircraft currently on firm order, which are scheduled for delivery in 20172018 through 2021.
Interest commitments related to the secured debt financing of 4053 delivered aircraft as of SeptemberJune 30, 20172018 are $19.5$40.3 million for the remainder of 2017, $52.9 million in 2018, $48.2$73.4 million in 2019, $43.6$67.0 million in 2020, $39.0$60.7 million in 2021, and $141.5$54.4 million in 2022, and $170.8 million in 2023 and beyond. For principal commitments related to these financed aircraft, refer to Note 10,12, Debt and Other Obligations. As of SeptemberJune 30, 2017,2018, principal and interest commitments related to the Company's future secured debt financing of 43 undelivered aircraft under bank debtthe Series 2017-1 EETC are zeroapproximately $2.7 million for the remainder of 2017, $16.5 million in 2018, $16.4$4.4 million in 2019, $17.3$4.0 million in 2020, $16.2$3.8 million in 2021, and $137.2$3.6 million in 2022, and $13.1 million in 2023 and beyond.
As of SeptemberJune 30, 2017,2018, the Company had a fleet consisting of 107119 A320 family aircraft. During the nine months ended SeptemberAs of June 30, 2017, the Company took delivery2018, this fleet was comprised of eleven aircraft financed under secured debt arrangements, two44 aircraft financed under operating leases, with lease term expirations between 2021 and 2029, and 75 purchased one previously leased aircraft, of which 22 were purchased off lease and returned one aircraft to its lessor.are currently unencumbered. In addition, the Company took deliveryas of two purchased engines and one engine financed under an operating lease, and purchased one previously leased engine. For further discussion on the previously leased aircraft and engine, refer to Note 3, Special Charges. New purchased aircraft are capitalized within flight equipment with depreciable lives of 25 years and estimated residual values of 10%. As of SeptemberJune 30, 2017,2018, the Company had 59 aircraft and 1112 spare engines financed under operating leases with lease term expiration dates ranging from 20172019 to 2029.2027, 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 and leaseback transactions with third-party aircraft lessors for the majority of these aircraft and engine leases. Deferred losses resulting from
Notes to Condensed Financial Statements—(Continued)

these sale and leaseback transactions are included in other long-term assets on the accompanying condensed balance sheets.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 creditsgains and other long-term liabilities on the accompanying condensed balance sheets.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)("Airbus") to reconfigure the seating and increase capacity in 40 of the Company’s A320ceos from 178 to 182 seats (reconfiguration)("reconfiguration"). The reconfiguration of the aircraft commenced in the first quarter of 2016 and is expected to bewas completed in the fourthsecond quarter of 2017 for a remaining committed cost2018. As of $0.6 million, as of SeptemberJune 30, 2017. These2018, the Company had no further commitments related to this agreement. The amounts will berelated to the reconfiguration are capitalized within flight equipment on the condensed balance sheets.sheet.
In September 2015, the Company executed a lease agreement with Wayne County Airport Authority (the Authority), which owns and operates Detroit Metropolitan Wayne County Airport (DTW). Under the lease agreement, the Company leases a 10-acre site, adjacent
Notes to the airfield at DTW, in order to construct, operate and maintain an approximately 126,000-square-foot hangar facility (the project). The project allows for the development of a maintenance hangar in order to fulfill the requirements of the Company's growing fleet and will reduce dependence on third-party facilities and contract maintenance. The lease agreement has a 30-year term with two 10-year extension options. Upon termination of the lease, title of the project, which will be fully depreciated, will automatically pass to the Authority. The Company completed the project during the first quarter of 2017 and has no remaining commitments related to this project as of September 30, 2017.Condensed Financial Statements—(Continued)


Future minimum lease payments under capital leases and noncancellable operating leases with initial or remaining terms in excess of one year at SeptemberJune 30, 20172018 were as follows:
  Capital Leases Aircraft and Spare Engine Leases Property Facility Leases 
Total
Operating and Capital Lease Obligations
 (in thousands)
remainder of 2017 $134
 $53,017
 $12,409
 $65,560
2018 537
 204,292
 43,726
 248,555
2019 504
 189,106
 36,512
 226,122
2020 188
 180,842
 25,604
 206,634
2021 28
 170,643
 12,740
 183,411
2022 and thereafter 
 570,120
 73,142
 643,262
Total minimum lease payments $1,391
 $1,368,020
 $204,133
 $1,573,544
Less amount representing interest 114
      
Present value of minimum lease payments $1,277
      
Less current portion 468
      
Long-term portion $809
      

  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 under thisrelated to the lease agreementof computer equipment are fixed for the 3-year term of the lease which began in the second quarter of 2017.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
Notes to Condensed Financial Statements—(Continued)

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 paypays maintenance reserves to aircraft lessors to be held as collateral in advance of the Company’s required performance of major maintenance activities. Substantially allA 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 $1.9$3.7 million for the remainder of 2017, $6.92018, $5.8 million in 2018,2019, $5.6 million in 2020, $5.7 million in 2019, $5.4 million in 2020, $5.5 million in 2021, and $17.7$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 in an amount equal to either (1) the amount of the maintenance reserves held by the lessor associated with the specific maintenance event or (2) the qualifying costs related to the specific maintenance event. Some of the master lease agreements do not require that the Company pay maintenance reserves asso long as the Company's cash balance does not fall below a certain level. As of SeptemberJune 30, 2017,2018, the Company wasis 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 SeptemberJune 30, 2017: $1.82018: $5.3 million for the remainder of 2017, $5.7 million in 2018, $1.6$12.5 million in 2019, $1.0$12.5 million in 2020, $0.5$9.8 million in 2021, $9.9 million in 2022, and $0.2$65.8 million thereafter. The Company's current agreementDuring the first quarter of 2018, the Company entered into a contract renewal with its reservation system provider which expires in 2018.2028.
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 ifprovided 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 SeptemberJune 30, 20172018 and December 31, 2016,2017, 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 SeptemberJune 30, 20172018 and December 31, 2016,2017, was $322.3$403.0 million and $234.6$286.3 million,, respectively.
Notes to Condensed Financial Statements—(Continued)

Employees
The Company has four union-represented employee groups that together represented approximately 75% of all employees at SeptemberJune 30, 2017.2018. The table below sets forth the Company's employee groups and status of the collective bargaining agreements as of SeptemberJune 30, 20172018.
Employee Groups Representative Amendable Date Percentage of Workforce
Pilots Air Line Pilots Association, International (ALPA)("ALPA") August 2015February 2023 26%27%
Flight Attendants Association of Flight Attendants (AFA-CWA)("AFA-CWA") May 2021 44%
Dispatchers Transport Workers Union (TWU)Professional Airline Flight Control Association ("PAFCA") August 2018 1%
Ramp Service Agents International Association of Machinists and Aerospace Workers (IAMAW)("IAMAW") June 2020 4%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)("NMB") to facilitate negotiations for an amended agreement and the Company joined ALPA in the request. The NMB has assigned mediators and the parties continue to work toward an amended agreement withIn January 2018, under the guidance of the mediator. UnderNMB assigned mediators, the Railway Labor Act (RLA), the parties' current agreement remains in effect until an amended agreement is reached.
In March 2016, under the supervision of the NMB, the Company and AFA-CWAparties reached a tentative agreement for a five-year contract withagreement. In February 2018, the Company's flight attendants. In May 2016, the flight attendantspilot group voted to approve the new five-year contractagreement with the Company. In connection with thisThe new agreement the Company paidincludes a $9.6 millionone-time ratification incentive ofand other negotiated contractual provisions which $8.4 million waswere recorded in special charges within salaries, wages and benefitsoperating expenses in the condensed statement of operations for the ninesix months ended SeptemberJune 30, 2016.2018. 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 $5.5$5.1 million and $5.7$3.9 million in health care claims as of SeptemberJune 30, 20172018 and December 31, 2016,2017, respectively.
Notes to Condensed Financial Statements—(Continued)

9.11.Fair Value Measurements
Under ASC 820, Fair"Fair Value Measurements and DisclosuresDisclosures", 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.
Notes to Condensed Financial Statements—(Continued)



The Company does not elect hedge accounting on its fuel derivative instruments.instruments, if any. As a result, the Company records the fair value adjustment of itsany fuel derivatives in the accompanying statement of operations within aircraft fuel and on the condensed balance sheetssheet 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 theany 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, isif 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. Based on the Company's assessment of the valuation model's sensitivity to changes in implied volatility, it concluded that holding other inputs constant, a significant increase (decrease) in implied volatility would result in a significantly higher (lower) fair value measurement for the Company's aircraft fuel derivatives. As of SeptemberJune 30, 20172018 and December 31, 2016,2017, the Company had no outstanding jet fuel derivatives.
Long-Term Debt
The estimated fair value of the Company's non-publicly heldterm 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 publicLevel 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 SeptemberJune 30, 20172018 and December 31, 20162017 were as follows:
 September 30, 2017 December 31, 2016 Fair Value Level Hierarchy
 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value 
 (in millions)  
Senior term loans$426.4
 $446.2
 $451.9
 $463.9
 Level 3
Junior term loans41.3
 42.7
 47.1
 48.1
 Level 3
Fixed-rate loans363.4
 370.1
 
 
 Level 3
Class A enhanced equipment trust certificates423.6
 440.6
 409.8
 416.0
 Level 2
Class B enhanced equipment trust certificates100.0
 103.3
 103.6
 105.7
 Level 2
Total long-term debt$1,354.7
 $1,402.9
 $1,012.4
 $1,033.7
  

 June 30, 2018 December 31, 2017 Fair Value Level Hierarchy
 Carrying Value Estimated Fair Value Carrying Value Estimated Fair Value 
 (in millions)  
Senior term loans$400.3
 $400.9
 $417.9
 $435.3
 Level 3
Junior term loans35.3
 35.6
 39.3
 40.4
 Level 3
Fixed-rate loans502.0
 489.5
 518.0
 528.6
 Level 3
2015-1 EETC Class A393.6
 394.8
 408.6
 420.9
 Level 2
2015-1 EETC Class B84.0
 84.6
 92.0
 94.2
 Level 2
2015-1 EETC Class C115.2
 114.9
 
 
 Level 2
2017-1 EETC Class AA190.0
 184.8
 37.5
 37.4
 Level 2
2017-1 EETC Class A63.3
 61.3
 12.5
 12.6
 Level 2
2017-1 EETC Class B70.0
 68.2
 13.8
 13.8
 Level 2
2017-1 EETC Class C65.7
 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 SeptemberJune 30, 20172018 and December 31, 20162017 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
Notes to Condensed Financial Statements—(Continued)



Short-term investment securities at SeptemberJune 30, 20172018 and December 31, 20162017 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 September 30, 2017Fair Value Measurements as of June 30, 2018
Total
Level
1

Level
2

Level
3
Total
Level
1

Level
2

Level
3

(in millions)(in millions)
Cash and cash equivalents$863.7

$863.7

$

$
$812.4

$812.4

$

$
Short-term investment securities100.7

100.7




101.7

101.7




Total assets$964.4

$964.4

$

$
$914.1

$914.1

$

$





















Total liabilities$

$

$

$
$

$

$

$
 Fair Value Measurements as of December 31, 2016
 Total
Level
1

Level
2

Level
3

(in millions)
Cash and cash equivalents$700.9

$700.9

$

$
Short-term investment securities100.2

100.2




Total assets$801.1

$801.1

$

$












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 securities100.9

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 nine monthsperiods ended SeptemberJune 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.



10.12.Debt and Other Obligations


As of SeptemberJune 30, 2017,2018, the Company heldhad 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:
Notes to Condensed Financial Statements—(Continued)

  As of Three Months Ended September 30, Nine Months Ended September 30,
 September 30, 2017 December 31, 2016 2017 2016 2017 2016
  (in millions) (weighted-average interest rates)
Fixed-rate senior term loans due through 2027 $426.4
 $451.9
 4.10% 4.10% 4.10% 4.10%
Fixed-rate junior term loans due through 2022 41.3
 47.1
 6.90% 6.90% 6.90% 6.90%
Fixed-rate loans due through 2029 363.4
 
 3.76% N/A
 3.76% N/A
Fixed-rate class A enhanced equipment trust certificates due through 2028 423.6
 409.8
 4.10% 4.03% 4.10% 4.03%
Fixed-rate class B enhanced equipment trust certificates due through 2024 100.0
 103.6
 4.45% 4.38% 4.45% 4.38%
Long-term debt $1,354.7
 $1,012.4
        
Less current maturities 106.0
 84.4
        
Less unamortized discounts

 34.6
 30.6
        
Total $1,214.1
 $897.4
        

  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 ninesix months ended SeptemberJune 30, 2017,2018, the Company made scheduled principal payments of $13.4$42.0 million and $63.4$60.6 million on its outstanding debt obligations, respectively. During the three and ninesix months ended SeptemberJune 30, 2016,2017, the Company made scheduled principal payments of $10.0$39.8 million and $29.6$50.0 million on its outstanding debt obligations, respectively.
At SeptemberJune 30, 2017,2018, long-term debt principal payments for the next five years and thereafter are as follows:
  September 30, 2017
  (in millions)
Remainder of 2017 $39.0
2018 108.0
2019 107.5
2020 107.1
2021 106.9
2022 and beyond 886.2
Total debt principal payments $1,354.7
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:
Notes to Condensed Financial Statements—(Continued)

 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 loans636
 775
 1,303
 1,578
Fixed-rate loans4,881
 1,586
 9,792
 1,744
Class A 2015-1 EETC4,015
 4,321
 8,157
 8,629
Class B 2015-1 EETC930
 1,108
 1,942
 2,292
Class C 2015-1 EETC789
 
 789
 
Class AA 2017-1 EETC1,576
 
 2,257
 
Class A 2017-1 EETC568
 
 814
 
Class B 2017-1 EETC654
 
 936
 
Class C 2017-1 EETC466
 
 466
 
Commitment fees51
 28
 103
 58
Amortization of debt discounts1,655
 1,290
 3,146
 2,521
Total$20,478
 $13,727
 $38,278
 $26,112

 Three Months Ended September 30, Nine Months Ended September 30,
2017 2016 2017 2016
 (in thousands)
Senior term loans$4,564
 $4,917
 $13,854
 $14,929
Junior term loans746
 879
 2,323
 2,721
Fixed-rate loans2,811
 
 4,555
 
Class A enhanced equipment trust certificates4,366
 3,538
 12,995
 7,419
Class B enhanced equipment trust certificates1,118
 1,015
 3,410
 2,124
Commitment fees29
 32
 87
 97
Amortization of debt discounts1,362
 979
 3,883
 2,289
Total$14,996
 $11,360
 $41,107
 $29,579




11.Subsequent Events

On October 25, 2017, the Company's 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.


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("the Securities Act)Act"), and Section 21E of the Securities Exchange Act of 1934, as amended (the("the Exchange Act)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, 20162017 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 FleetTM, is one of the youngest fleet of any majorand most fuel efficient in the U.S. airline,We currently operatesoperate more than 480500 daily flights to 6067 destinations in the United States, CaribbeanLatin America and Latin America.the Caribbean. Our stock trades under the symbol "SAVE" on the NASDAQ Global SelectNew York Stock Market.Exchange ("NYSE").


Our ultra low-cost carrier, or ULCC, business model allows us to compete principally by offering customers our Bare FaresTM, which are unbundled base fares that remove components traditionally included in the price of an airline ticket. We then give customers Frill ControlTM, which provides customers the freedom to save by paying only for the options they choose, such as bags and advance seat assignments and refreshments.assignments. We record revenue related to these options as non-fare passenger revenue, which is recorded within passenger revenues in our financial statements as non-ticket revenue.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 SimpleTM 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 nine-month periodssix-month period ended SeptemberJune 30, 20172018 and 20162017:
 
Three Months Ended September 30, Percent ChangeThree Months Ended June 30, Percent Change
2017 2016 2018 2017 
Operating Statistics (unaudited) (A):          
Average aircraft105.5
 87.4
 20.7 %118.7
 102.8
 15.5 %
Aircraft at end of period107
 89
 20.2 %119
 104
 14.4 %
Average daily aircraft utilization (hours)11.6
 12.3
 (5.7)%12.6
 11.7
 7.7 %
Average stage length (miles)1,006
 968
 3.9 %1,051
 982
 7.0 %
Block hours112,701
 98,586
 14.3 %136,357
 109,296
 24.8 %
Departures42,599
 38,310
 11.2 %49,404
 41,563
 18.9 %
Passenger flight segments (PFSs) (thousands)6,307
 5,674
 11.2 %7,554
 6,206
 21.7 %
Revenue passenger miles (RPMs) (thousands)6,452,529
 5,599,370
 15.2 %7,961,128
 6,219,638
 28.0 %
Available seat miles (ASMs) (thousands)7,681,312
 6,507,204
 18.0 %9,515,842
 7,294,578
 30.5 %
Load factor (%)84.0% 86.0% (2.0) pts
83.7% 85.3% (1.6) pts
Average ticket revenue per passenger flight segment ($)56.48
 58.34
 (3.2)%
Average non-ticket revenue per passenger flight segment ($)52.48
 51.17
 2.6 %
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 ($)108.96
 109.51
 (0.5)%112.76
 112.82
 (0.1)%
Average yield (cents)10.65
 11.10
 (4.1)%10.70
 11.26
 (5.0)%
TRASM (cents)8.95
 9.55
 (6.3)%8.95
 9.60
 (6.8)%
CASM (cents)7.59
 7.47
 1.6 %7.81
 7.80
 0.1 %
Adjusted CASM (cents)7.48
 7.35
 1.8 %7.76
 7.78
 (0.3)%
Adjusted CASM ex-fuel (cents)5.42
 5.48
 (1.1)%5.17
 5.83
 (11.3)%
Fuel gallons consumed (thousands)90,274
 78,288
 15.3 %106,144
 85,533
 24.1 %
Average economic fuel cost per gallon ($)1.75
 1.56
 12.2 %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".







Nine Months Ended September 30, Percent ChangeSix Months Ended June 30, Percent Change
2017 2016 2018 2017 
Operating Statistics (unaudited) (A):          
Average aircraft101.9
 84.1
 21.2 %116.4
 100.0
 16.4 %
Aircraft at end of period107
 89
 20.2 %119
 104
 14.4 %
Average daily aircraft utilization (hours)11.7
 12.6
 (7.1)%12.3
 11.8
 4.2 %
Average stage length (miles)991
 978
 1.3 %1,038
 983
 5.6 %
Block hours326,033
 290,529
 12.2 %259,310
 213,332
 21.6 %
Departures123,492
 111,495
 10.8 %94,386
 80,893
 16.7 %
Passenger flight segments (PFSs) (thousands)18,083
 16,268
 11.2 %14,092
 11,775
 19.7 %
Revenue passenger miles (RPMs) (thousands)18,285,588
 16,219,093
 12.7 %14,774,647
 11,833,060
 24.9 %
Available seat miles (ASMs) (thousands)21,851,789
 18,909,627
 15.6 %17,924,606
 14,170,478
 26.5 %
Load factor (%)83.7% 85.8% (2.1) pts
82.4% 83.5% (1.1) pts
Average ticket revenue per passenger flight segment ($)56.84
 55.32
 2.7 %
Average non-ticket revenue per passenger flight segment ($)52.69
 51.85
 1.6 %
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 ($)109.53
 107.17
 2.2 %110.41
 109.57
 0.8 %
Average yield (cents)10.83
 10.75
 0.7 %10.53
 10.90
 (3.4)%
TRASM (cents)9.06
 9.22
 (1.7)%8.68
 9.10
 (4.6)%
CASM (cents)7.71
 7.33
 5.2 %8.29
 7.77
 6.7 %
Adjusted CASM (cents)7.64
 7.15
 6.9 %7.76
 7.71
 0.6 %
Adjusted CASM ex-fuel (cents)5.62
 5.45
 3.1 %5.25
 5.72
 (8.2)%
Fuel gallons consumed (thousands)254,871
 225,851
 12.8 %201,147
 164,597
 22.2 %
Average economic fuel cost per gallon ($)1.73
 1.42
 21.8 %2.24
 1.71
 31.0 %


(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".





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.

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 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.

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.



Executive Summary
For the thirdsecond quarter of 20172018, we achieved a 15.1%12.7% operating margin, a decrease of 6.76.1 points compared to the prior year period. We generated pre-tax income of $94.8$15.1 million and net income of $60.211.3 million on operating revenues of $687.2851.8 million. For the thirdsecond quarter of 20162017, we generated pre-tax income of $128.0122.6 million and net income of $81.477.2 million on operating revenues of $621.3$700.2 million.
Our adjusted CASM ex-fuel for the thirdsecond quarter of 20172018 was 5.425.17 cents, a 1.1%an 11.3% decrease year over year. The decrease on a per-ASM basis was primarily due to decreases in maintenance, materials and repairs, salaries, wages and benefitsother operating expense and aircraft rent expense, partially offset by increases in other operating and depreciation and amortization expense.
During the third quarter 2017, we had over 1,650 flight cancellations related to Hurricanes Harvey, Irma and Maria. We estimate that this unusually intense hurricane season, together with the overhang of the pilot-related work action earlier in the year, negatively impacted our third quarter operating income by approximately $39 million.
As of SeptemberJune 30, 2017,2018, we had 107119 Airbus A320-family aircraft in our fleet comprised of 31 A319s, 5453 A320s, 30 A321s, and 22 A321s.5 A320neos. With the scheduled delivery of 6 aircraft and the retirement of 17 aircraft during the remainder of 2017,2018 and a contract currently under negotiation for the delivery of an additional 2 aircraft, we expect to end 20172018 with 112128 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 engine,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 fourthfirst quarter of 2017,2018, the support agreement was extended through the end of 2017.February 2018. The

support agreement providesprovided for compensation to the Company for grounded aircraft, if any, and for back-up spare engines. We are currently negotiating certain milestone dates for remediation of the introductory into-service issuescontinuously work with Pratt & Whitney.Whitney to secure support and relief in connection with possible engine related operation disruptions.


Comparison of three months ended SeptemberJune 30, 20172018 to three months ended SeptemberJune 30, 20162017
Operating Revenues
Operating revenues increased $65.9151.6 million, or 10.6%21.6%, to $687.2851.8 million for the thirdsecond quarter of 20172018, as compared to the thirdsecond quarter of 2016,2017, due primarily to an increase in traffic of 15.2%28.0%, offset by a decrease in passenger yields of 4.1% 5.0%.
Total revenue per available seat mile (TRASM)("TRASM") for the thirdsecond quarter of 20172018 was 8.95 cents, a decrease of 6.3%6.8%, as compared to the thirdsecond quarter of 2016.2017. This decrease was primarily driven bydue to lower passenger yields, year over year, resulting from aggressive competitive pricingdriven in manypart by an increase in average stage length and the calendar shift of our markets. In addition, load factor decreased by 2.0 points,the Easter holiday, year over year.
Total revenue per passenger flight segment decreased 0.5%,slightly year over year, driven by a decrease of 3.2% in ticketyear. Fare revenue per passenger flight segment offset by an increase of 2.6% indecreased 2.8% and non-ticket revenue per passenger flight segment.segment increased 3.0%. The decrease in ticketfare revenue per passenger flight segment was primarily driven by a 4.1%5.0% decrease in average yield, period over period, due to a more aggressive pricing environment 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 increased $97.0$174.4 million, or 20.0%30.7%, to $583.1$743.3 million for the thirdsecond quarter of 20172018 compared to $486.1$568.9 million for the thirdsecond quarter of 2016,2017, primarily due to an increase in operations as reflected by an 18.0%a 30.5% capacity growth and a 15.2%28.0% increase in traffic. OperatingFurthermore, operating expenses also increased as a result of a 15.3% increase in fuel gallons consumed and a 12.2%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 ninethree months ended SeptemberJune 30, 20172018 and 2016.2017. 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 increased in the thirdsecond quarter of 2018 by $103.9 million, or 73.0%, compared to $142.3 million in the second quarter of 2017, by $36.5 million, or 29.9%, compared to $121.8 million in the third quarter of 2016, due to a 15.3% increase in fuel gallons consumed and a 12.2%39.8% increase in average economic fuel cost per gallon.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 September 30,

 2017
2016

(in thousands, except per gallon amounts)
Percent Change
Fuel gallons consumed90,274

78,288

15.3%
Into-plane fuel cost per gallon1.75

1.56

12.2%
Into-plane fuel expense$158,300

$121,844

29.9%
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)$158,300

$121,844

29.9%


 Three Months Ended June 30,

 2018
2017

(in thousands, except per gallon amounts)
Percent Change
Fuel gallons consumed106,144

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 12.2%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 September 30,

Three Months Ended June 30,

2017
2016
2018
2017

(in thousands, except per gallon amounts)
Percent Change(in thousands, except per gallon amounts)
Percent Change
Into-plane fuel expense$158,300

$121,844

29.9%$246,180

$142,294

73.0%
Realized losses (gains) related to fuel derivative contracts, net



NM




NM
Economic fuel expense$158,300

$121,844

29.9%$246,180

$142,294

73.0%
Fuel gallons consumed90,274

78,288

15.3%106,144

85,533

24.1%
Economic fuel cost per gallon$1.75

$1.56

12.2%$2.32

$1.66

39.8%




During the three months ended SeptemberJune 30, 20172018 and 2016,2017, 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 SeptemberJune 30, 20172018 and 20162017, followed by explanations of the material changes on a dollar basis and/or unit cost basis:

Three Months Ended September 30, Dollar Change Percent Change Cost per ASM Per-ASM Change Percent ChangeThree Months Ended June 30, Dollar Change Percent Change Cost per ASM Per-ASM Change Percent Change
2017 2016 2017 2016 2018 2017 2018 2017 
(in thousands)   (in cents)  (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$134,114
 $120,190
 $13,924
 11.6 % 1.75
 1.85
 (0.10) (5.4)%187,756
 129,892
 57,864
 44.5 % 1.97
 1.78
 0.19
 10.7 %
Aircraft fuel158,300
 121,844
 36,456
 29.9 % 2.06
 1.87
 0.19
 10.2 %
Aircraft rent53,396
 49,367
 4,029
 8.2 % 0.70
 0.76
 (0.06) (7.9)%41,745
 52,566
 (10,821) (20.6)% 0.44
 0.72
 (0.28) (38.9)%
Landing fees and other rents48,498
 39,345
 9,153
 23.3 % 0.63
 0.60
 0.03
 5.0 %58,602
 45,592
 13,010
 28.5 % 0.62
 0.63
 (0.01) (1.6)%
Depreciation and amortization36,840
 25,304
 11,536
 45.6 % 0.48
 0.39
 0.09
 23.1 %45,618
 35,331
 10,287
 29.1 % 0.48
 0.48
 
  %
Maintenance, materials and repairs26,176
 30,443
 (4,267) (14.0)% 0.34
 0.47
 (0.13) (27.7)%31,653
 28,985
 2,668
 9.2 % 0.33
 0.40
 (0.07) (17.5)%
Distribution29,469
 25,565
 3,904
 15.3 % 0.38
 0.39
 (0.01) (2.6)%34,997
 29,835
 5,162
 17.3 % 0.37
 0.41
 (0.04) (9.8)%
Special charges7,853
 7,355
 498
 NM
 0.10
 0.11
 (0.01) NM
174
 
 174
 NM
 
 
 
 NM
Loss on disposal of assets516
 423
 93
 NM
 0.01
 0.01
 
 NM
4,644
 1,493
 3,151
 NM
 0.05
 0.02
 0.03
 NM
Other operating87,965
 66,277
 21,688
 32.7 % 1.15
 1.02
 0.13
 12.7 %91,881
 102,885
 (11,004) (10.7)% 0.97
 1.41
 (0.44) (31.2)%
Total operating expenses$583,127
 $486,113
 $97,014
 20.0 % 7.59
 7.47
 0.12
 1.6 %$743,250
 $568,873
 $174,377
 30.7 % 7.81
 7.80
 0.01
 0.1 %
Adjusted CASM (1)        7.48
 7.35
 0.13
 1.8 %        7.76
 7.78
 (0.02) (0.3)%
Adjusted CASM ex-fuel (2)        5.42
 5.48
 (0.06) (1.1)%        5.17
 5.83
 (0.66) (11.3)%
 
(1)Reconciliation of CASM to Adjusted CASM:


Three Months Ended September 30,Three Months Ended June 30,
2017 20162018 2017
(in millions) Per ASM (in millions) Per ASM(in millions) Per ASM (in millions) Per ASM
CASM (cents)  7.59
   7.47
  7.81
   7.80
Unrealized losses (gains) related to fuel derivative contracts, net$
 
 $
 
$
 
 $
 
Loss on disposal of assets0.5
 0.01
 0.4
 0.01
4.6
 0.05
 1.5
 0.02
Special charges7.9
 0.10
 7.4
 0.11
0.2
 
 
 
Adjusted CASM (cents)  7.48
   7.35
  7.76
   7.78


(2)Excludes aircraft fuel expense, loss on disposal of assets and special charges.
Our adjusted CASM ex-fuel for the thirdsecond quarter of 20172018 was down 1.1%11.3% as compared to the thirdsecond quarter of 2016.2017. The decrease on a per-ASM basis was primarily due to decreases in maintenance, materials and repairs, salaries, wages and benefitsother operating expense and aircraft rent expense, partially offset by increases in other operating and depreciation and amortization expense.
Labor costs for the thirdsecond quarter of 20172018 increased $13.9$57.9 million, or 11.6%44.5%, as compared to the thirdsecond quarter of 2016,2017. The increase on both a dollar and per-ASM basis was primarily driven by a 22.2%21.3% increase in our pilot and flight attendant workforce resulting from an increase to our aircraft fleet of 1815 additional aircraft, net of 2 aircraft lease returns, since the thirdsecond quarter of 2016, offset by2017. In addition, effective March 1, 2018, our pilots received a decreaserate increase in incentive compensation and sick-time expense. On a per-ASM basis, labor costs decreased due to lower incentive compensation expense resulting from lower metric performance, year over year, as well as a decreaseconnection with the new pilot agreement approved in our sick-time expense.February 2018.
Aircraft rent expense for the thirdsecond quarter of 2017 increased2018 decreased by $4.0$10.8 million, or 8.2%20.6%, as compared to the thirdsecond quarter of 2016.2017. This increasedecrease in aircraft rent expense was primarily driven by the deliverypurchase of seven new14 A319 aircraft financed under operating leases, subsequent tooff lease completed during the end of the thirdsecond quarter of 2016. This increase was partially offset by the purchase of two aircraft since the end of the third quarter of 2016, which were formerly financed under operating lease agreements.2018. For additional information, refer to Note 5, Special Charges. On a per-ASM basis, aircraft rent expense decreased 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 14 aircraft, of which 2


increased capacity but had no effect on aircraft rent expense, as these assets were previously financed under operating lease agreements.purchased and are being depreciated over their useful life.
Landing fees and other rents for the thirdsecond quarter of 20172018 increased $9.2$13.0 million, or 23.3%28.5%, as compared to the thirdsecond quarter of 2016,2017, primarily due to an 11.2%18.9% increase in departures. In addition, on both a dollar and per-ASM basis, landing fees and other rents increased due to increased volume at higher cost airports, year over year, as well as 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 increased by $11.5$10.3 million, or 45.6%29.1%, 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 1417 new aircraft made since the thirdsecond quarter of 2016.2017.
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 $14.2$9.7 million and $10.1$14.6 million for the thirdsecond quarters of 2018 and 2017, and 2016, 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 $40.4$41.4 million and $40.5$43.6 million for the thirdsecond quarters of 20172018 and 2016,2017, respectively.
Maintenance, materials and repairs expense for the thirdsecond quarter of 2017 decreased2018 increased by $4.3$2.7 million, or 14.0%9.2%, as compared to the thirdsecond quarter of 2016.2017. The decreaseincrease in maintenance costs on a dollar basis was due to routine and ongoing maintenance on a growing fleet. On a per-unit basis, was primarily due to amaintenance costs decreased numberas the timing and mix of scheduled maintenance events resulted in the current period as compared to the prior year period as well as lower aircraft repair expense year over year.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 increased by $3.9$5.2 million, or 15.3%17.3%, in the thirdsecond quarter of 20172018 as compared to the thirdsecond quarter of 2016.2017. The increase on a dollar basis was primarily due to increased sales volume. On a per-ASM basis, distribution costs remained relatively stable.


decreased primarily due to lower average fare resulting in a decrease in credit card fees year over year.
Other operating expense for the thirdsecond quarter of 2017 increased2018 decreased by $21.7$11.0 million, or 32.7%10.7%, as compared to the thirdsecond quarter of 20162017 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 passenger re-accommodation expense year over year.ground handling rates. As compared to the prior year period, we increased departures by 11.2%18.9% and had 11.2%21.7% more passenger flight segments, which drove increases in variable operating expenses. Other operating expense per ASM increased primarily due to higher passenger re-accommodation expense, as compared to the prior year period.
Special charges for the third quarter of 2017 consisted of $7.9 million in lease termination charges recognized in connection with the purchase of 1 aircraft, which was formerly financed under an operating lease agreement. For the third quarter of 2016, special charges consisted of $7.4 million in lease termination charges recognized in connection with the purchase of 3 aircraft formerly financed under operating lease agreements. 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 further discussion on this purchase, please see "Notes to Condensed Financial Statements - 3. Special Charges."




Other Income (Expenses)


Our interest expense and corresponding capitalized interest for the three months ended SeptemberJune 30, 20172018 and 20162017 primarily represents interest related to the financing of purchased aircraft. As of SeptemberJune 30, 2018 and 2017, we had 53 and 2016, the Company had 40 and 2836 aircraft financed through secured long-term debt arrangements, respectively. Please see "Notes to Condensed Financial Statements—10.12. Debt and Other Obligations" for further discussion.


Our interest income for the three months ended SeptemberJune 30, 20172018 primarily represents interest income earned on cash, cash equivalents, and short-term investments. Interest income for the three months ended September 30, 2016 primarily represents interest income earned on cash, cash equivalentsinvestments 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 thirdsecond quarter of 20172018 was 36.5%25.7% compared to 36.4%37.0% for the thirdsecond quarter of 2016. In arriving at these rates,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 considered a variety of factors, including our forecasted full-year pre-tax results, the U.S. federal rate of 35%, expected nondeductible expenses, and estimated state income taxes. We evaluateexpect 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 quarterstate and make adjustments when necessary. Our finalthe state tax rate applicable to such income. Discrete items particular to a given year may also affect our effective tax rate for the full year is dependent on the level of pre-tax income and the magnitude of any nondeductible expenses in relation to the respective pre-tax income.rates.


Comparison of ninesix months ended SeptemberJune 30, 20172018 to ninesix months ended SeptemberJune 30, 20162017
Operating Revenues
Operating revenues increased $237.1$265.8 million, or 13.6%20.6%, to $1,980.7$1,555.9 million for the ninesix months ended SeptemberJune 30, 2017,2018, compared to the prior year period, due primarily to an increase in traffic of 12.7% and an increase24.9%, offset by a decrease in passenger yields of 0.7%3.4%.
TRASM for the ninesix months ended SeptemberJune 30, 20172018 was 9.068.68 cents, a decrease of 1.7%4.6% compared to the same period of 2016.2017. This decrease was driven by a more aggressive competitive pricing environment noted in the third quarter of 2017 which put pressure on ourlower passenger yields for the nine months ended September 30, 2017. In addition,and a decrease in load factor, decreased by 2.1 points, as compared to the prioryear over year.
Total revenue per passenger flight segment increased 2.2%slightly from $107.17$109.57 for the ninesix months ended SeptemberJune 30, 20162017 to $109.53$110.41 for the ninesix months ended SeptemberJune 30, 2017.2018. Our average ticket fare revenue per passenger flight segment increaseddecreased from $55.32$56.94 to $56.84,$55.51, or 2.7%2.5%, as compared to the prior year period, and non-ticket revenue per passenger flight segment increased from $51.85$52.63 to $52.69,$54.90, or 1.6%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 increased for the ninesix months ended SeptemberJune 30, 20172018 by $299.2$385.7 million, or 21.6%35.0%, as compared to the same period for 20162017 primarily due to our 15.6%a 26.5% capacity growth and a 12.7%24.9% increase in traffic. OperatingFurthermore, operating expenses also increased as a result of ana 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.
Aircraft fuel expense for the nine months ended September 30, 2017 increased $119.4 million, or 37.2%, compared to the prior year period as a result of a 21.8% increase in average economic fuel price per gallon and a 12.8% increase in fuel gallons consumed.
The elements of the changes in aircraft fuel expense are illustrated in the following table:
Nine Months Ended September 30,

Six Months Ended June 30,

2017
2016
2018
2017

(in thousands, except per gallon amounts)
Percent Change(in thousands, except per gallon amounts)
Percent Change
Fuel gallons consumed254,871

225,851

12.8%201,147

164,597

22.2%
Into-plane fuel cost per gallon$1.73

$1.42

21.8%$2.24

$1.71

31.0%
Into-plane fuel expense$440,376

$321,018

37.2%$450,826

$282,076

59.8%
Realized losses (gains) related to fuel derivative contracts, net



NM




NM
Unrealized losses (gains) related to fuel derivative contracts, net



NM




NM
Aircraft fuel expense (per Statement of Operations)$440,376

$321,018

37.2%$450,826

$282,076

59.8%
The elements of the changes in economic fuel expense are illustrated in the following table:


Nine Months Ended September 30,

Six Months Ended June 30,

2017
2016
2018
2017
(in thousands, except per gallon amounts) Percent Change(in thousands, except per gallon amounts) Percent Change
Into-plane fuel expense$440,376

$321,018

37.2%$450,826

$282,076

59.8%
Realized losses (gains) related to fuel derivative contracts, net



NM




NM
Economic fuel expense$440,376

$321,018

37.2%$450,826

$282,076

59.8%
Fuel gallons consumed254,871

225,851

12.8%201,147

164,597

22.2%
Economic fuel cost per gallon$1.73

$1.42

21.8%$2.24

$1.71

31.0%
During the ninesix months ended SeptemberJune 30, 20172018 and 2016,2017, 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 ninesix months ended SeptemberJune 30, 20172018 and 2016,2017, followed by explanations of the material changes on a unit cost basis and/or dollar basis:
Nine Months Ended September 30, Dollar Change Percent Change Cost per ASM Per-ASM Change Percent ChangeSix Months Ended June 30, Dollar Change Percent Change Cost per ASM Per-ASM Change Percent Change
2017 2016 2017 2016 2018
2017 2018
2017 
(in thousands)   (in cents)  (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$391,144
 $349,530
 $41,614
 11.9% 1.79
 1.85
 (0.06) (3.2)%342,852
 257,030
 85,822
 33.4 % 1.91
 1.81
 0.10
 5.5 %
Aircraft fuel440,376
 321,018
 119,358
 37.2% 2.02
 1.70
 0.32
 18.8 %
Aircraft rent163,032
 151,433
 11,599
 7.7% 0.75
 0.80
 (0.05) (6.3)%91,936
 109,636
 (17,700) (16.1)% 0.51
 0.77
 (0.26) (33.8)%
Landing fees and other rents134,538
 114,096
 20,442
 17.9% 0.62
 0.60
 0.02
 3.3 %108,232
 86,040
 22,192
 25.8 % 0.60
 0.61
 (0.01) (1.6)%
Depreciation and amortization103,680
 73,370
 30,310
 41.3% 0.47
 0.39
 0.08
 20.5 %84,991
 66,840
 18,151
 27.2 % 0.47
 0.47
 
  %
Maintenance, materials and repairs81,473
 72,010
 9,463
 13.1% 0.37
 0.38
 (0.01) (2.6)%61,363
 55,297
 6,066
 11.0 % 0.34
 0.39
 (0.05) (12.8)%
Distribution85,875
 73,190
 12,685
 17.3% 0.39
 0.39
 
  %65,628
 55,607
 10,021
 18.0 % 0.37
 0.39
 (0.02) (5.1)%
Special charges (credits)12,629
 31,609
 (18,980) NM
 0.06
 0.17
 (0.11) NM
89,342
 4,776
 84,566
 NM
 0.50
 0.03
 0.47
 NM
Loss on disposal of assets3,114
 1,166
 1,948
 NM
 0.01
 0.01
 
 NM
5,492
 2,598
 2,894
 NM
 0.03
 0.02
 0.01
 NM
Other operating268,553
 197,833
 70,720
 35.7% 1.23
 1.05
 0.18
 17.1 %185,523
 180,588
 4,935
 2.7 % 1.04
 1.27
 (0.23) (18.1)%
Total operating expenses$1,684,414
 $1,385,255
 $299,159
 21.6% 7.71
 7.33
 0.38
 5.2 %$1,486,185
 $1,100,488
 $385,697
 35.0 % 8.29
 7.77
 0.52
 6.7 %
Adjusted CASM (1)        7.64
 7.15
 0.49
 6.9 %        7.76
 7.71
 0.05
 0.6 %
Adjusted CASM ex-fuel (2)        5.62
 5.45
 0.17
 3.1 %        5.25
 5.72
 (0.47) (8.2)%
 
(1)Reconciliation of CASM to Adjusted CASM:
Nine Months Ended September 30,Six Months Ended June 30,
2017 20162018 2017
(in millions) Per ASM (in millions) Per ASM(in millions) Per ASM (in millions) Per ASM
CASM (cents)  7.71
   7.33
  8.29
   7.77
Unrealized losses (gains) related to fuel derivative contracts, net$
 
 $
 
$
 
 $
 
Loss on disposal of assets3.1
 0.01
 1.2
 0.01
5.5
 0.03
 2.6
 0.02
Special charges12.6
 0.06
 31.6
 0.17
89.3
 0.5
 4.8
 0.03
Adjusted CASM (cents)  7.64
   7.15
  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 ninesix months ended SeptemberJune 30, 2017 increased2018 decreased by 3.1%8.2% as compared to the same period in 2016.2017. The increasedecrease on a per-ASM basis was primarily due to increasesdecreases in aircraft rent expense and other operating and depreciation and amortization expense, partially offset by decreases in special charges and salaries, wages and benefits expense.


Labor costs for the ninesix months ended SeptemberJune 30, 20172018 increased $41.6$85.8 million, or 11.9%33.4%, as compared to the same period in 2016.2017. The increase on both a dollar and per-ASM basis was primarily driven by an 18.5%a 24.2% increase in our pilot and flight attendant workforce resulting from an increase to our aircraft fleet of 1815 additional aircraft, net of 2 aircraft lease returns, since the end of the thirdsecond quarter of 2016, partially offset by2017. In addition, effective March 1, 2018, our pilots received a decreaserate increase in incentive compensation expense year over year. On a per-ASM basis, labor costs decreased primarily due to lower incentive compensation expense, year over year, resulting from lower metric performance and the ratification incentive inconnection with the new flight attendant contract of $8.4 million recorded during the first quarter of 2016.pilot agreement approved in February 2018.
Aircraft rent expense for the ninesix months ended SeptemberJune 30, 2017 increased2018 decreased by $11.6$17.7 million, or 7.7%16.1%, as compared to the same period in 2016.2017. This increasedecrease in aircraft rent expense was primarily driven by the deliverypurchase of seven new14 A319 aircraft financed under operating leases, subsequentoff 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 enddecrease year over year. Costs associated with return conditions of the third quarterleased aircraft are recorded as supplemental rent within aircraft rent expense on our statement of 2016. This increase was partially offset by the purchase of two aircraft since the end of the third quarter of 2016, which were formerly financed under operating lease agreements.operations. On a per-ASM basis, aircraft rent expense decreased 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 14


17 new aircraft, of which 2 were previously financed under operating lease agreements. This decrease was partially offset by an increase in return costs for two leased aircraft. Costs associated with return conditions of leased aircraft are recorded as supplemental rent withinincreased capacity but had no effect on aircraft rent expense, on our statement of operations.as these assets were purchased and are being depreciated over their useful life.
Landing fees and other rents for the ninesix months ended SeptemberJune 30, 20172018 increased $20.4$22.2 million, or 17.9%25.8%, as compared to the same period in 20162017 primarily due to a 10.8%16.7% increase in departures. In addition, on both a dollar and per-ASM basis, landing fees and other rents increased due to increased volume at higher cost airports, year over year, as well as 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 increased by $30.3$18.2 million, or 41.3%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 1417 new aircraft made since the thirdsecond quarter of 2016.2017.
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 $42.1$21.4 million and $33.0$27.9 million for the ninesix months ended SeptemberJune 30, 2018 and 2017, and 2016, 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 $123.5$82.7 million and $105.1$83.2 million for the ninesix months ended SeptemberJune 30, 20172018 and 2016,2017, respectively.
Maintenance, materials and repairs expense for the ninesix months ended SeptemberJune 30, 20172018 increased by $9.5$6.1 million, or 13.1%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 remained relatively stabledecreased as compared to the prior year period.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 increased by $12.7$10.0 million, or 17.3%18.0%, for the ninesix months ended SeptemberJune 30, 20172018 as compared to the same period in 2016.2017. 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 ninesix months ended SeptemberJune 30, 20172018 increased by $70.7$4.9 million, or 35.7%2.7%, as compared to the prior year period, primarily due to an increase in overall operations and higher passenger re-accommodation expense year over year.operations. As compared to the prior year period, we increased departures by 10.8%16.7% and had 11.2%19.7% more passenger flight segments, which drove increases in variable operating expenses. OtherImproved 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 per ASM increased primarily due to higher passenger re-accommodation expense, as compared to the prior year period.on a per-ASM basis.
Special charges for the ninesix months ended SeptemberJune 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 $12.6$4.8 million in lease termination charges recognized in connection with the purchase of 1 aircraft and 1an engine which were formerly financed under an operating lease agreements. For the nine months ended September 30, 2016, special charges consisted of $31.6 million in lease termination charges recognized in connection with the purchase of 6 aircraft formerly financed under operating lease agreements.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 further discussion on this purchase,additional information, please seerefer to "Notes to Condensed Financial Statements - 3.5. Special Charges."




Other income (expenses)


Our interest expense and corresponding capitalized interest for the ninesix months ended SeptemberJune 30, 20172018 and 20162017 primarily represents interest related to the financing of purchased aircraft. As of SeptemberJune 30, 20172018 and 2016,2017, the Company had 4053 and 2836 aircraft financed through secured long-term debt arrangements, respectively. Please see "Notes to Condensed Financial Statements—10.12. Debt and Other Obligations" for further discussion.
Our interest income for the ninesix months ended SeptemberJune 30, 20172018 primarily represents interest income earned on cash, cash equivalents, and short-term investments. Interest income for the nine months ended September 30, 2016 primarily represents interest income earned on cash, cash equivalentsinvestments 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 ninesix months ended SeptemberJune 30, 20172018 was 37.1%24.4% compared to 36.7%37.4% for the ninesix months ended SeptemberJune 30, 2016. In arriving at these rates,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 considered a variety of factors, including our forecasted full-year pre-tax results, the U.S. federal rate of 35%, expected nondeductible expenses, and estimated state income taxes. We evaluateexpect 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 quarterstate and make adjustments when necessary. Our finalthe state tax rate applicable to such income. Discrete items particular to a given year may also affect our effective tax rate for the full year is dependent on the level of pre-tax income and the magnitude of any nondeductible expenses in relation to the respective pre-tax income.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)("PDPs"), debt obligations and maintenance reserves. Our total cash at SeptemberJune 30, 20172018 was $863.7$812.4 million, an increase of $162.8$11.5 million from December 31, 2016. As2017. In addition to cash and cash equivalents, as of SeptemberJune 30, 2017,2018, we had $100.7$101.7 million in short-term available-for-sale investment securities.
Currently, one of our largest capital expenditure needs is funding the acquisition costs of our aircraft. Aircraft aremay be acquired through debt financing, sale leaseback transactions,cash purchases, direct leases or cash purchases. In debt financing transactions, capital is needed to make equity investments in capital assets and payments on debt obligations (principal and interest) after the acquisition of the aircraft.sale leaseback transactions. During the ninesix months ended SeptemberJune 30, 2017,2018, we purchased 117 aircraft through debt financing transactions and 2 engines through cash purchases. During the nine months ended September 30, 2017, we made $93.8$90.8 million in debt payments (principal, interest and fees) on our outstanding debt obligations. Capital resources required underThe debt financing transactions will generally be higher than those involving sale leaseback transactions.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 sale leaseback transactions, capital is needed to fundaddition, during the initial purchase of the aircraft prior to the sale to the lessor. During the ninesix months ended SeptemberJune 30, 2017, we entered into no sale leaseback transactions. During the nine months ended September 30, 2017,2018, we purchased one enginesix engines through cash purchases and one aircraft, which were previously financed under operating lease agreements, for $8.1 million and $20.0 million, respectively, comprised of a cash payment of $3.8 million and $12.6 million, respectively, and the non-cash application of maintenance and security deposits held by the previous lessor of $4.3 million and $7.4 million, respectively.sold five engines.
Under our agreement with Airbus for aircraft, and International Aero Engines AG (IAE)("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 ninesix months ended SeptemberJune 30, 2017,2018, we paid $121.7$92.2 million ofin PDPs, net of refunds, and $8.1$4.2 million of capitalized interest for future deliveries of aircraft and spare engines. As of SeptemberJune 30, 2017,2018, we had $304.7$240.2 million of PDPs, including capitalized interest, on our condensed balance sheet.
As of SeptemberJune 30, 2017,2018, we had secured bank debt financing for 43 aircraft, scheduled for delivery in the remainder of 2017,2018, and did not have financing commitments in place for the remaining 6149 Airbus firm aircraft orders, scheduled for delivery between 20172018 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 a portionsome 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. InDuring the ninesix months ended SeptemberJune 30, 20172018, we recorded an increase of $28.4$11.2 million in maintenance reserves, net of reimbursements, and as of SeptemberJune 30, 20172018, we had $305.1248.4 million ($166.4107.3 million in aircraft maintenance deposits and $138.7141.2 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 ninesix months ended SeptemberJune 30, 20172018 provided $386.5$251.0 million in cash compared to $440.0$323.7 million provided in the ninesix months ended SeptemberJune 30, 2016.2017. The decrease is primarily driven by higher operating costs specifically aircraft fuel, other operatingdue 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 salaries, wages, and benefits, whichdeferred heavy maintenance, year over year. These decreases were slightlypartially offset by higher revenues, as compared to the prior period. The decrease is also attributed to an income tax refund of $65.0 million receivedincreases in the prior period while no refund was received in 2017.special charges, non-operating and other liabilities.
Net Cash Flows Used In Investing Activities. In the ninesix months ended SeptemberJune 30, 2017,2018, investing activities used $558.8$410.8 million, compared to $663.8$355.9 million used in the prior year period. The decreaseincrease was mainly driven by the initial investment in our available-for-sale investment security portfolio made in the prior period. During the nine months ended September 30, 2016, we purchased $100.0 million of available-for-sale investment securities while in the current period all investment purchases were made from reinvestment of proceeds generated from the maturity of our investment securities. In


addition, we had a decrease in the purchase of property and equipment, year over year, resulting from decreasedincreased purchases of aircraft and engines.
Net Cash Flows Provided By Financing Activities. During the ninesix months ended SeptemberJune 30, 2017,2018, financing activities provided $335.1$171.4 million in cash compared to $246.0$200.4 million provided in the ninesix months ended SeptemberJune 30, 2016.2017. We received $405.8$440.3 million in connection with the 2015-1C and 2017-1C EETCs and the debt financing of elevenrelated to seven aircraft delivered during the ninesix months ended SeptemberJune 30, 2017 and2018. In addition, we paid $63.6$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 SeptemberJune 30, 20172018 and the periods in which payments are due (in millions):
 remainder of 2017 2018 - 2019 2020 - 2021 2022 and beyond Total  remainder of 2018 2019 - 2020 2021 - 2022 2023 and beyond Total
Long-term debt (1) $39
 $216
 $214
 $886
 $1,355
 $77
 $303
 $291
 $1,249
 $1,920
Interest commitments (2) 20
 101
 83
 142
 346
 40
 140
 115
 171
 466
Capital and operating lease obligations 66
 475
 390
 643
 1,574
 114
 402
 340
 520
 1,376
Flight equipment purchase obligations 228
 1,302
 1,605
 25
 3,160
 346
 1,422
 802
 8
 2,578
Other (3) 2
 7
 2
 
 11
 5
 25
 20
 66
 116
Total future payments on contractual obligations $355
 $2,101
 $2,294
 $1,696
 $6,446
 $582
 $2,292
 $1,568
 $2,014
 $6,456


(1) Includes principal only associated with senior term loans due through 2027,and junior term loans, due through 2022, fixed-rate loans due through 2029,Class A, Class B, and Class AC Series 2015-1 EETCs, and Class AA, Class A, Class B, enhanced equipment trust certificates due through 2028 and 2024, respectively.Class C Series 2017-1 EETCs. Refer to "Notes to the Financial Statements - 10.12. 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, enhanced equipment trust certificates only.and Class C Series 2017-1 EETCs.
(3) Primarily related to our reservation system new airport kiosks and our A320ceo seating reconfiguration project.other miscellaneous subscriptions and services. Refer to "Notes to the Financial Statements - 8.10. 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 $1.9$3.7 million for the remainder of 2017, $6.92018, $5.8 million in 2018,2019, $5.6 million in 2020, $5.7 million in 2019, $5.4 million in 2020, $5.5 million in 2021, and $17.7$4.9 million in 2022, and $12.9 million in 2023 and beyond.


As of SeptemberJune 30, 2017,2018, principal and interest commitments related to our future secured debt financing for 43 undelivered aircraft to be financed under the Series 2017-1 EETC are zero$2.7 million for the remainder of 2017, $16.5 million in 2018, $16.4$4.4 million in 2019, $17.3$4.0 million in 2020, $16.2$3.8 million in 2021, and $137.2$3.6 million in 2022, and $13.1 million in 2023 and beyond.


In September 2015, we executed a lease agreement with Wayne County Airport Authority (the Authority), which owns and operates Detroit Metropolitan Wayne County Airport (DTW). Under the lease agreement, we lease a 10-acre site, adjacent to the airfield at DTW, in order to construct, operate and maintain an approximately 126,000-square-foot hangar facility. The lease agreement has a 30-year term with two 10-year extension options. Upon termination of the lease, title of the project, which will be fully depreciated, will automatically pass to the Authority. We completed the project during the first quarter of 2017 and have no remaining commitments related to this project as of September 30, 2017.




Off-Balance Sheet Arrangements
We have significant lease obligations for our aircraft and spare engines as 5944 of our 107119 aircraft and 1112 of our 1518 spare engines are financed under operating leases and therefore are therefore not reflected on our condensed balance sheets. These leases expire between 20172019 and 2029.2031. Aircraft rent payments were $55.0$52.5 million and $53.5$56.9 million for the three months ended SeptemberJune 30, 20172018 and 2016,2017, respectively, and $168.6$109.1 million and $160.3$113.6 million for the ninesix months ended SeptemberJune 30, 20172018 and 2016,2017, respectively. Our aircraft lease payments for 5843 of our aircraft are fixed-rate obligations. One of our aircraft leases provide for variable rent payments, which fluctuate based on changes in the LondonLIBOR (London Interbank Offered Rate (LIBOR)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 SeptemberJune 30, 20172018, our firm aircraft orders consisted of the following:


 Airbus  Airbus 
 A320ceo A320neo A321ceo Total A320ceo A320neo Total
remainder of 2017 2 
 4 6
2018 5 
 5 10
remainder of 2018 7 
 7
2019 1 14 
 15 2 9 11
2020 
 16 
 16 
 16 16
2021 
 18 
 18 
 18 18
 8 48 9 65 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 fourtwo spare engine orders for V2500 SelectTwo engines with IAE and nine spare engine orders for PurePower PW1100G-JMPW 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 $227.8$345.6 million for the remainder of 2017, $528.4 million inremainder of 2018, $773.7$600.7 million in 2019, $820.5$821.6 million in 2020, $784.8$785.1 million in 2021, and $24.6$16.8 million in 2022 and $7.9 million in 2023 and beyond.
As of SeptemberJune 30, 2017,2018, we had lines of credit related to corporate credit cards of $33.6 million from which we had drawn $10.8$1.1 million.
As of SeptemberJune 30, 2017,2018, we had lines of credit with counterparties for both physical fuel delivery and derivatives in the amount of $51.5 million. As of SeptemberJune 30, 2017,2018, we had drawn $13.7$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 SeptemberJune 30, 20172018, we did not hold any derivatives.
As of SeptemberJune 30, 2017,2018, we had $8.2have $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 $17.8$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, and special charges (credits),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, and special charges (credits),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.""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 non-ticket revenue per passenger flight segment” means the total non-ticket revenue divided by passenger flight segments.
“Average ticket revenue per passenger flight segment” means total passenger revenue divided by passenger flight segments.
“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” or “PFS” 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.”“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 ninesix months ended SeptemberJune 30, 20172018 and 20162017 represented 26.1%approximately 30.3% and 23.2%25.6% of our operating expenses, respectively. IncreasesVolatility 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 $57$78 million.
As of SeptemberJune 30, 20172018 and December 31, 2016,2017, we had nodid 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 thisthe amount based upon further fluctuations in futuresfuture prices. Outstanding financial derivative instruments could 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 $100.7$101.7 million and $100.2$100.9 million, as of SeptemberJune 30, 20172018 and December 31, 2016,2017, 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 SeptemberJune 30, 2017,2018, we had $1,354.7$1,919.4 million outstanding in fixed-rate debt related to the purchase of 1923 Airbus A320 aircraft and 2130 Airbus A321 aircraft which had a fair value of $1,402.9$1,900.1 million. As of December 31, 2016,2017, we had $1,012.4$1,539.6 million outstanding in fixed-rate debt related to the purchase of 1521 Airbus A320 aircraft and 1425 Airbus A321 aircraft, which had a fair value of $1,033.7$1,583.2 million.






ITEM 4.CONTROLS AND PROCEDURES
Evaluation of Disclosure Controls and Procedures
Our management,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 SeptemberJune 30, 20172018. 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 Securities and Exchange Commission’sSEC’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 Company’sour 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 SeptemberJune 30, 20172018, 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 SeptemberJune 30, 20172018, 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, 2016,2017, filed with the Securities and Exchange Commission on February 13, 2017,2018, other than modifications toas disclosed in Part II, Item 1A. Risk Factors contained in our Quarterly Report on Form 10-Q for the following risk factor.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.

We depend on a limited number of suppliers for our aircraft and engines.

One of the elements of our business strategy is to save costs by operating a single-family aircraft fleet - currently Airbus A320-family, single-aisle aircraft, powered by engines manufactured by IAE and Pratt & Whitney. If any of Airbus, IAE, or Pratt & Whitney become unable to perform its contractual obligations, or if we are unable to acquire or lease aircraft or engines from these or other owners, operators or lessors on acceptable terms, we would have to find other suppliers for a similar type of aircraft or engine. If we have to lease or purchase aircraft from another supplier, we would lose the significant benefits we derive from our current single fleet composition. We may also incur substantial transition costs, including costs associated with retraining our employees, replacing our manuals and adapting our facilities and maintenance programs. Our operations could also be harmed by the failure or inability of aircraft, engine and parts suppliers to provide sufficient spare parts or related support services on a timely basis, particularly in connection with new-generation introductory technology. Our business would be significantly harmed if a design defect or mechanical problem with any of the types of aircraft, engines or components currently on order or that we operate were discovered that would halt or delay our aircraft delivery stream or that would ground any of our aircraft while the defect or problem was corrected, assuming it could be corrected at all. For example, introductory issues with the new-generation PW1100G-JM engines, designed and manufactured by Pratt & Whitney, have resulted in the intermittent grounding of certain of our A320neo aircraft. During the fourth quarter of 2016, and continuing through the third quarter of 2017, we have experienced and continue to experience various reliability problems associated with the new engine resulting in the grounding of two of our five A320neo aircraft which we expect to continue until the defect or problem is corrected. In part, due to issues involving the new engine, we renegotiated our aircraft delivery schedule. We originally had four A320neos scheduled for delivery in 2018 of which two were converted to A320ceo aircraft, to be delivered in 2017, and the remaining two are deferred until 2019. We cannot be certain that this defect will be corrected or if the defect will require the grounding of the remaining A320neos. These types of events, if appropriate design or mechanical modifications cannot be adequately implemented, could materially adversely affect our business, results of operations and financial condition. Moreover, the use of our aircraft could be suspended or restricted by regulatory authorities in the event of actual or perceived mechanical or design problems. Our business would also be significantly harmed if the public began to avoid flying with us due to an adverse perception of the types of aircraft, engines or components that we operate stemming from safety concerns or other problems, whether real or perceived, or in the event of an accident involving those types of aircraft, engines or components. Carriers that operate a more diversified fleet are better positioned than we are to manage such events.

Airlines are often affected by factors beyond their control, including: air traffic congestion at airports; air traffic control inefficiencies; adverse weather conditions, such as hurricanes or blizzards; increased security measures; new travel related taxes or the outbreak of disease, any of which could harm our business, operating results and financial condition.

Like other airlines, our business is affected by factors beyond our control, including air traffic congestion at airports, air traffic control inefficiencies, adverse weather conditions, increased security measures, new travel related taxes, the outbreak of disease, new regulations or policies from the presidential administration and Congress. Factors that cause flight delays frustrate passengers and increase costs, which in turn could adversely affect profitability. The federal government currently controls all U.S. airspace, and airlines are completely dependent on the FAA to operate that airspace in a safe, efficient and affordable manner. The air traffic control system, which is operated by the FAA, faces challenges in managing the growing demand for U.S. air travel. U.S. and foreign air-traffic controllers often rely on outdated technologies that routinely overwhelm the system and compel airlines to fly inefficient, indirect routes resulting in delays. A significant portion of our operations is concentrated in markets such as South Florida, the Caribbean, Latin America and the Northeast and Northern Midwest regions of the United States, which are particularly vulnerable to weather, airport traffic constraints and other delays. Adverse weather conditions and natural disasters, such as hurricanes affecting southern Florida and the Caribbean (such as Hurricanes Irma and Maria in September 2017) as well as southern Texas (such as Hurricane Harvey in August 2017), winter snowstorms or the September 2017 earthquakes in Mexico City, Mexico, can cause flight cancellations, significant delays and certain facility disruptions. For example, during 2017 the timing and location of Hurricanes Irma and Maria produced a domino effect on our operations resulting in approximately 1,400 flight cancellations and numerous flight delays, which resulted in an adverse effect on our results of operations. Cancellations or delays due to adverse weather conditions or natural disasters, air traffic control problems or inefficiencies, breaches in security or other factors may affect us to a greater degree than other, larger airlines that may be able to recover more quickly from these events, and therefore could harm our business, results of operations and financial condition to a greater degree than other air carriers. Because of our high utilization, point-to-point network, operational disrupt



ions can have a disproportionate impact on our ability to recover. In addition, many airlines reaccommodate their disrupted passengers on other airlines at prearranged rates under flight interruption manifest agreements. We have been unsuccessful in procuring any of these agreements with our peers, which makes our recovery from disruption more challenging than for larger airlines that have these agreements in place. Similarly, outbreaks of pandemic or contagious diseases, such as ebola, measles, avian flu, severe acute respiratory syndrome (SARS), H1N1 (swine) flu and Zika virus, could result in significant decreases in passenger traffic and the imposition of government restrictions in service and could have a material adverse impact on the airline industry. Increased travel taxes, such as those provided in the Travel Promotion Act, enacted March 10, 2010, which charges visitors from certain countries a $10 fee every two years to travel into the United States to subsidize certain travel promotion efforts, could also result in decreases in passenger traffic. Any general reduction in airline passenger traffic could have a material adverse effect on our business, results of operations and financial condition.






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 thirdsecond quarter of 2017.2018. 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 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
July 1-31, 2017 
 $
 
 $
August 1-31, 2017 552
 $37.74
 
 $
September 1-30, 2017 
 $
 
 $
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 552
 $37.74
 
   745
 $36.89
 
  


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.


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
10.1+4.1 

   
12.14.2 
4.3
4.4
4.5
4.6
4.7
4.8
4.9
4.10
4.11


4.12
4.13
   
31.1 
   
31.2 
   
32.1* 
   
32.2* 
   
101.INS XBRL Instance Document - The instance document does not appear in the interactive data file because its XBRL tags are embedded within the inline XBRL document.
   
101.SCH XBRL Taxonomy Extension Schema
   
101.CAL XBRL Taxonomy Extension Calculation Linkbase
   
101.LAB XBRL Taxonomy Extension Label Linkbase
   
101.PRE XBRL Taxonomy Extension Presentation Linkbase
 
+Indicates a management contract or compensatory plan or arrangement.
*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: OctoberJuly 26, 20172018 By:/s/ Edward M. Christie   
  Edward M. Christie
  
Executive Vice President and
Chief Financial Officer




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