LONG-TERM DEBT

Long-term debt obligations (in millions):



	2016			2015
Fixed-rate notes payable due through 2028	$	1,179		$	520
Variable-rate notes payable due through 2028	1,803			166
Less debt issuance costs	(18		)	(3		)
Long-term debt	2,964			683
Less current portion	319			114
	$	2,645		$	569

Weighted-average fixed-interest rate	4.4		%	5.7		%
Weighted-average variable-interest rate	2.4		%	1.8		%

During 2016, the Company's total debt increased $2.3 billion, primarily due to the addition of $2.0 billion of secured debt financing from multiple lenders to fund the acquisition of Virgin America. Approximately $1.6 billion of the loans are secured by a total of 56 aircraft, including 37 B737-900ER aircraft and 19 B737-800 aircraft. An additional $400 million is secured by Air Group's interest in certain aircraft purchase agreements. The remainder is due to assumed debt from Virgin America. During 2016, the Company made debt payments of $249 million, including $95 million of debt extinguishment that arose from the Virgin America acquisition, and $12 million related to prepayments of existing loans. The Company's variable-rate notes payable bear interest at a floating rate per annum equal to a margin plus the three or six-month LIBOR in effect at the commencement of each semi-annual or three-month period, as applicable. As of December 31, 2016, none of the Company's borrowings were restricted by financial covenants.

Long-term debt principal payments for the next five years and thereafter (in millions):



	Total
2017	$	321
2018	351
2019	424
2020	451
2021	424
Thereafter	1,007
Total principal payments	$	2,978

Bank Line of Credit

The Company has two $100 million credit facilities and one $52 million credit facility. All three facilities have variable interest rates based on LIBOR plus a specified margin. One of the $100 million facilities, which expires in September 2017, is secured by aircraft. The other $100 million facility, which expires in March 2017, is secured by certain accounts receivable, spare engines, spare parts and ground service equipment. The $52 million facility expires in October 2017 with a mechanism for annual renewal and is secured by two aircraft. The Company has secured letters of credit against the $52 million facility, but has no plans to borrow using either of the two remaining facilities. All three credit facilities have a requirement to maintain a minimum unrestricted cash and marketable securities balance of $500 million. The Company was in compliance with this covenant at December 31, 2016.