DETAIL OF SELECTED BALANCE SHEET ACCOUNTS

Allowance for Doubtful Accounts

Activity in our allowance for doubtful accounts receivable consisted of the following (in thousands):



	Three months ended June 30,						Nine months ended June 30,
	2017			2016			2017			2016
Balance at beginning of period	$	310		$	976		$	811		$	746
Bad debt expense (recovery)	(129		)	(118		)	(226		)	221
Uncollectible accounts written off, net of recoveries	(92		)	16			(493		)	(98		)
Change due to foreign currency translation	1			(3		)	(2		)	2
Balance at end of period	$	90		$	871		$	90		$	871

Inventories

The components of inventories are summarized below (in thousands):



	June 30, 2017		September 30, 2016
Raw materials, parts and subassemblies, net	$	18,244	$	25,525
Work-in-progress	784		996
Total inventories	$	19,028	$	26,521

Cost and Estimated Earnings on Uncompleted Contracts

The components of costs and estimated earnings and related amounts billed on uncompleted contracts are summarized below (in thousands):



	June 30, 2017			September 30, 2016
Costs incurred on uncompleted contracts	$	1,025,641		$	1,088,921
Estimated earnings	334,072			350,125
	1,359,713			1,439,046
Less: Billings to date	(1,355,468		)	(1,416,914		)
Net underbilled position	$	4,245		$	22,132
Included in the accompanying balance sheets under the following captions:
Costs and estimated earnings in excess of billings on uncompleted contracts	$	46,127		$	66,106
Billings in excess of costs and estimated earnings on uncompleted contracts	(41,882		)	(43,974		)
Net underbilled position	$	4,245		$	22,132

Accrued Product Warranty

Activity in our product warranty accrual consisted of the following (in thousands):



	Three months ended June 30,						Nine months ended June 30,
	2017			2016			2017			2016
Balance at beginning of period	$	3,649		$	4,787		$	4,639		$	4,930
Increase to warranty expense	593			1,174			1,313			3,332
Deduction for warranty charges	(949		)	(1,206		)	(2,618		)	(3,481		)
Change due to foreign currency translation	39			(26		)	(2		)	(52		)
Balance at end of period	$	3,332		$	4,729		$	3,332		$	4,729