At March 31, 2019, the Company leased 28 aircraft under noncancelable operating leases with remaining terms of up to 5 years. The Company has the option to terminate certain leases at various times throughout the lease. The Company headquarters and other facility noncancelable operating leases have remaining terms of up to 7 years. The leases require the Company to pay all taxes, maintenance, insurance, and other operating expenses. Rental expense is recognized on a straight-line basis over the lease term, net of lessor rebates and other incentives. Aggregate rental expense under all operating aircraft, equipment and facility leases totaled approximately $18.7 million and $22.4 million for the three months ended March 31, 2019 and 2018, respectively, and $37.8 million and $44.1 million for the six months ended March 31, 2019 and 2018, respectively.

Future minimum lease payments as of March 31, 2019, under noncancelable operating leases are as follows (in thousands):

Periods Ending September 30,	Aircraft		Other		Total
Remainder of 2019		27,619		1,658		29,277
2020		45,534		1,963		47,497
2021		44,314		1,375		45,689
2022		29,751		1,339		31,090
2023		12,418		1,308		13,726
Thereafter		11,849		2,704		14,553
Total	$	171,485	$	10,347	$	181,832

The majority of the Company's leased aircraft are leased through trusts that have a sole purpose to purchase, finance, and lease these aircraft to the Company; therefore, they meet the criteria of a variable interest entity. However, since these are single-owner trusts in which the Company does not participate, the Company is not at risk for losses and is not considered the primary beneficiary. Management believes that the Company's maximum exposure under these leases is the remaining lease payments.