Summary of Significant Accounting Policies (Details) - USD ($)			1 Months Ended	12 Months Ended
	Dec. 10, 2020	Sep. 04, 2020	Mar. 31, 2020	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Restricted Cash
Cash dividends declared per share	$ 0.50	$ 0.65
Total cash dividend payment	$ 8,600,000			$ 11,200,000
Cash and cash equivalents				8,265,606	$ 12,603,967
Restricted cash				0	11,180,900
Total cash and cash equivalents and restricted cash				8,265,606	23,784,867	$ 22,416,830	$ 20,390,713
Inventory Valuation
Raw materials				3,729,692	3,378,246
Work-in-process				629,814	656,382
Finished goods				185,886	256,707
Inventories				4,545,392	4,291,335
Property and Equipment
Payment to acquire property and equipment				340,678	118,797	81,281
Long-Lived Assets
Impairment charges				0	0	0
Contract Balances
Balance at beginning of the period (contract liabilities)				313,365
Contract asset additions					(80,182)	80,182
Performance obligations satisfied during the period that were included in the contract liability balance at the beginning of the period				(305,494)
Increases due to invoicing prior to satisfaction of performance obligations				409,633
Balance at end of the period (contract liabilities)				417,504	313,365
Customer Service Revenue
Customer Service Cost of Sales				10,263,166	9,793,224	7,676,119
Gross profit				$ 12,781,630	$ 11,801,975	$ 9,896,470
Income taxes
U.S. Federal statutory tax rate (as a percent)				21.00%	21.00%	21.00%
Customer Service
Customer Service Revenue
Customer Service Sales				$ 4,034,294	$ 4,265,086	$ 3,553,919
Customer Service Cost of Sales				1,489,942	1,457,995	1,374,227
Gross profit				$ 2,544,352	$ 2,807,091	$ 2,179,692
COVID 19
Income taxes
Amount of pre-tax NOL carried back two years to fully offset taxable income			$ 1,500,000
AMT tax			16,000
Cash impact of carryback			309,412
COVID 19 | R&D
Income taxes
Increase in R&D credit carryforward			$ 196,000
Property Plant and Equipment Other than Air Transportation Equipment and Manufacturing Facility | Minimum
Property and Equipment
Estimated useful lives				3 years
Property Plant and Equipment Other than Air Transportation Equipment and Manufacturing Facility | Maximum
Property and Equipment
Estimated useful lives				7 years
Corporate airplanes
Property and Equipment
Estimated useful lives				10 years
Manufacturing facility
Property and Equipment
Estimated useful lives				39 years