13. Significant Customer Concentrations (Tables)

12 Months Ended

Mar. 31, 2017

Risks and Uncertainties [Abstract]

Schedules of Concentration of Risk, by Risk Factor [Table Text Block]

Net sales to foreign customers were $1,782,646 and $1,900,724 for the years ended March 31, 2017 and 2016, respectively. All other sales were to customers located in the U.S. The following table presents net sales by U.S. and foreign countries:

	2017		2016
United States	$	16,962,810	$	22,904,101
Foreign countries		1,782,646		1,900,724
Total Avionics Sales	$	18,745,456	$	24,804,825