Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Disaggregation of Revenue [Line Items]
Revenue	$ 21,052	$ 21,299
Revenue from Contract with Customer | Customer Concentration Risk | Transferred over Time
Disaggregation of Revenue [Line Items]
Concentration risk	41.00%	54.00%
North America
Disaggregation of Revenue [Line Items]
Revenue	$ 15,474	$ 17,294
Europe
Disaggregation of Revenue [Line Items]
Revenue	5,578	4,005
Fixed wing aircraft
Disaggregation of Revenue [Line Items]
Revenue	9,939	10,726
Rotorcraft
Disaggregation of Revenue [Line Items]
Revenue	3,150	4,380
Energy components for power generation units
Disaggregation of Revenue [Line Items]
Revenue	6,191	4,624
Commercial product and other revenue
Disaggregation of Revenue [Line Items]
Revenue	1,772	1,569
Commercial revenue
Disaggregation of Revenue [Line Items]
Revenue	13,240	10,181
Military revenue
Disaggregation of Revenue [Line Items]
Revenue	$ 7,812	$ 11,118