Note 9 - Intangible Assets and Goodwill (Details Textual) - USD ($)	12 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Amortization of Intangible Assets, Total	$ 368,000	$ 323,000
Goodwill, Ending Balance	4,417,605	4,417,605
Contrail Aviation Support, Inc. [Member]
Goodwill, Ending Balance	$ 4,200,000	$ 4,200,000

The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.

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