13. Significant Customer Concentrations (Tables)

12 Months Ended

Mar. 31, 2019

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

Net sales to foreign customers were $2,438,228 and $2,599,808 for the years ended March 31, 2019 and 2018, respectively. All other sales were to customers located in the U.S. The following table presents net sales by U.S. and foreign countries:

	2019		2018
United States	$	9,677,822	$	7,424,780
Foreign countries		2,438,228		2,599,808
Total Avionics Sales	$	12,116,050	$	10,024,588