Certain significant amounts included in the Company's condensed consolidated balance sheet as of March 31, 2020 and September 30, 2019, consisted of the following (in thousands):

	March 31,			September 30,
	2020			2019
Expendable parts and supplies, net:
Expendable parts and supplies	$	26,527		$	25,336
Less: obsolescence and other		(4,149	)		(3,999	)
	$	22,378		$	21,337

Prepaid expenses and other current assets:
Prepaid aircraft rent	$	-		$	35,786
Deferred offering and reimbursed costs		1,514			2,092
Other		4,397			3,045
	$	5,911		$	40,923
Property and equipment, net:
Aircraft and other flight equipment	$	1,588,462		$	1,582,199
Other equipment		5,122			5,122
Leasehold improvements		2,797			2,797
Vehicles		962			924
Building		699			699
Furniture and fixtures		302			302
Total property and equipment		1,598,344			1,592,043
Less: accumulated depreciation		(355,547	)		(318,458	)
	$	1,242,797		$	1,273,585

Other accrued expenses:
Accrued property taxes	$	5,707		$	9,186
Accrued interest		4,488			4,497
Accrued vacation		5,538			6,128
Accrued wheels, brakes and tires		2,705			1,513
Other		8,700			7,564
	$	27,138		$	28,888

The Company monitors for any indicators of impairment of the long-lived fixed assets. When certain conditions or changes in the economic situation such as the current environment brought by COVID-19 exist, the assets may be impaired and the carrying amount of the assets exceed its fair value. The assets need to be tested for recoverability of carrying amount.

To determine whether impairments exist, we group assets at the Capacity Purchase Agreement and fleet-type level (i.e., the lowest level for which there are identifiable cash flows) and then estimate future cash flows based on projections of capacity purchase arrangements, block hours, maintenance events, labor costs and other relevant factors. Due to our reduced flying schedules and projections of future cash flows, we evaluated each of our fleets to determine if any of the fleets are impaired.

Based on our carrying amount recoverability test, we have concluded that no fleet was impaired as of March 31, 2020 as the future cash flows exceeded the carrying value of our long-lived fixed assets. Given the uncertain future amid COVID-19, we will conduct additional tests in 3^rd quarter 2020.

Depreciation expense totaled approximately $20.1 million and $18.8 million for the three months ended March 31, 2020 and 2019, respectively, and $40.3 million and $36.9 million for the six months ended March 31, 2020 and 2019, respectively.

Prior to the Company’s adoption of Topic 842 on October 1, 2019, the Company recorded amortization of the unfavorable lease liability of approximately $1.5 million for the three months ended March 31, 2019 as a reduction to lease expense. Upon the Company’s adoption of Topic 842, the unfavorable lease liability is now included in its ROU asset balance and amortized therein.