Note 2 - Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Apr. 30, 2019	Apr. 30, 2018
Promissory notes		$ 2,387
Long-Term Debt
Notes payable	3,975	3,347
Less: Current maturities	1,899	1,612
	2,076	1,735
Note Collateralized by Real Estate [Member]
Promissory notes		2,387
Notes Collateralized by Aircraft Security Agreements, Due January 2020 [Member]
Long-Term Debt
Notes payable	119	270
Notes Collateralized by Aircraft Security Agreements [Member]
Long-Term Debt
Notes payable	2,239
Notes Collateralized by Aircraft Security Agreements, Due January 2023 [Member]
Long-Term Debt
Notes payable
Note Payable 1, Interest at Bank Paid Off in 2019 [Member]
Long-Term Debt
Notes payable		62
Note Payable 2, Interest at Bank Paid Off in 2019 [Member]
Long-Term Debt
Notes payable		65
Note Payable 3, Interest at Bank Paid Off in 2019 [Member]
Long-Term Debt
Notes payable		147
Note Collateralized by Real Estate Due June 2024 [Member]
Long-Term Debt
Notes payable	241	259
Note Collateralized by BNSC's Assets and Compensation due under State Management Contract Due May 2020 [Member]
Long-Term Debt
Notes payable	1,313	2,464
Note Collateralized by Equipment Due April 2022 [Member]
Long-Term Debt
Notes payable	$ 63	$ 80

The carrying value as of the balance sheet date of the current portion of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

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