4. Notes Payable

Notes payable consisted of the following:


	March 31,		December 31,
	2016		2015
	(in thousands)
Credit facility at a floating rate of interest of LIBOR plus 2.75%, secured by engines. The facility has a committed amount of $700.0 million at March 31, 2016, which revolves until the maturity date of June 2019.	$	539,000	$	549,000

WEST II Series 2012-A term notes payable at a fixed rate of interest of 5.50%, maturing in September 2037. Secured by engines.		294,337		300,467

Note payable at fixed interest rates ranging from 2.60% to 2.97%, maturing in July 2024. Secured by an aircraft.		15,719		16,135

Note payable at a variable interest rate of LIBOR plus 2.25%, maturing in January 2018. Secured by engines.		12,739		13,082

Notes payable		861,795		878,684

Less: unamortized debt issuance costs		(11,764)		(12,595)
Total notes payable	$	850,031	$	866,089

At March 31, 2016 , we had a revolving credit facility to finance the acquisition of aircraft engines for lease as well as for general working capital purposes. On April 20, 2016 we entered into a Third Amended and Restated Credit Agreement which increased the revolving credit facility to $890.0 million from $700.0 million and extended the term to April 2021. This $890 million revolving credit facility has an accordion feature up to $1 billion. The initial interest rate on the facility is LIBOR plus 2.75%. Quarterly, the interest rate is adjusted based on the Company’s leverage ratio, as calculated under the terms of the revolving credit facility.

For further information on our debt instruments, see the "Notes Payable" note in Part II, Item 8 of our Annual Report on Form 10-K for the year ended December 31, 2015.

The following is a summary of the aggregate maturities of our long-term debt at March 31, 2016:


Year	(in thousands)
2016	$	17,091
2017		23,624
2018		33,294
2019		562,430
2020		23,031
Thereafter		202,325
	$	861,795