Note 9 - Segment Information (Details) - Schedule of Segment Reporting Information, by Segment - USD ($)	3 Months Ended		6 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Net sales	$ 3,912,168	$ 2,222,941	$ 7,218,630	$ 4,037,155
Cost of Sales	2,038,535	1,223,728	3,763,393	2,556,629
Gross Margin	1,873,633	999,213	3,455,237	1,480,526
Engineering, research, and Development	525,739	503,380	1,050,842	1,020,703
Selling, general, and administrative	625,163	555,411	1,237,634	1,121,936
Litigation expenses	91,553	35,848	102,060	75,119
Change in fair value of common stock warrant	(5,500)	0	73,000	0
Interest income	(1,018)	(1,009)	(2,018)	(2,007)
Interest expense - judgment	90,596	72,003	171,106	143,223
Interest expense, net	10,866	24,990	28,603	59,035
Total expenses	1,337,399	1,190,623	2,661,227	2,418,009
Income (loss) before income taxes	536,234	(191,410)	794,010	(937,483)
Avionics Government [Member]
Segment Reporting Information [Line Items]
Net sales	3,140,454	1,284,099	5,644,594	2,376,681
Cost of Sales	1,626,089	714,590	2,868,656	1,475,844
Gross Margin	1,514,365	569,509	2,775,938	900,837
Avionics Commercial [Member]
Segment Reporting Information [Line Items]
Net sales	771,714	938,842	1,574,036	1,660,474
Cost of Sales	412,446	509,138	894,737	1,080,785
Gross Margin	359,268	429,704	679,299	579,689
Avionics Total [Member]
Segment Reporting Information [Line Items]
Net sales	3,912,168	2,222,941	7,218,630	4,037,155
Cost of Sales	2,038,535	1,223,728	3,763,393	2,556,629
Gross Margin	1,873,633	999,213	3,455,237	1,480,526
Engineering, research, and Development	525,739	503,380	1,050,842	1,020,703
Selling, general, and administrative	278,026	194,179	512,604	411,307
Litigation expenses	0	0
Change in fair value of common stock warrant	0
Interest income	0	0
Interest expense - judgment	0
Interest expense, net	0	0
Total expenses	803,765	697,559	1,563,446	1,432,010
Income (loss) before income taxes	1,069,868	301,654	1,891,791	48,516
Corporate Segment [Member]
Segment Reporting Information [Line Items]
Net sales	0	0
Cost of Sales	0	0
Gross Margin	0	0
Engineering, research, and Development	0	0
Selling, general, and administrative	347,137	361,232	725,030	710,629
Litigation expenses	91,553	35,848	102,060	75,119
Change in fair value of common stock warrant	(5,500)		73,000
Interest income	(1,018)	(1,009)	(2,018)	(2,007)
Interest expense - judgment	90,596	72,003	171,106	143,223
Interest expense, net	10,866	24,990	28,603	59,035
Total expenses	533,634	493,064	1,097,781	985,999
Income (loss) before income taxes	$ (533,634)	$ (493,064)	$ (1,097,781)	$ (985,999)