Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jul. 31, 2017	Apr. 30, 2017
CURRENT ASSETS:
Cash	$ 5,901	$ 6,389
Accounts receivable	3,781	4,095
Inventories
Raw materials	5,897	5,644
Work in process	1,126	1,174
Finished goods	52	39
Total inventory	7,075	6,857
Prepaid expenses and other current assets	1,214	994
Total current assets	17,971	18,335
PROPERTY, PLANT AND EQUIPMENT:
Land and building	5,197	5,132
Aircraft	5,888	5,888
Machinery and equipment	3,801	3,639
Office furniture and fixtures	6,563	6,497
Leasehold improvements	4,032	4,032
	25,481	25,188
Accumulated depreciation	(14,859)	(14,506)
Total property, plant and equipment	10,622	10,682
SUPPLEMENTAL TYPE CERTIFICATES (net of accumulated amortization of $4,549 at July 31, 2017 and $4,345 at April 30, 2017)	6,367	6,354
OTHER ASSETS:
Deferred tax asset	925	925
Other assets (net of accumulated amortization of $7,241 at July 31, 2017 and $6,904 at April 30, 2017)	6,365	6,482
Total other assets	7,290	7,407
Total assets	42,250	42,778
CURRENT LIABILITIES:
Promissory notes	2,528	2,604
Current maturities of long-term debt	2,086	2,297
Accounts payable	1,854	1,919
Customer deposits	1,198	892
Gaming facility mandated payment	853	1,227
Compensation and compensated absences	1,147	1,478
Income tax payable	721	589
Other current liabilities	198	129
Total current liabilities	10,585	11,135
LONG-TERM DEBT, NET OF CURRENT MATURITIES	2,944	3,347
Total liabilities	13,529	14,482
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Common stock, par value $.01: authorized 100,000,000 shares issued 65,273,896 and outstanding 64,543,550 shares at July 31, 2017 and issued 65,273,896 and outstanding 64,543,550 shares at April 30, 2017	652	652
Capital contributed in excess of par	13,980	13,980
Treasury stock at cost, 730,346 shares	(764)	(764)
Retained earnings	9,957	9,719
Total stockholders' equity Butler National Corporation	23,825	23,587
Noncontrolling interest in BHCMC, LLC	4,896	4,709
Total stockholders' equity	28,721	28,296
Total liabilities and stockholders' equity	42,250	42,778
Preferred Class A [Member]
STOCKHOLDERS' EQUITY:
Preferred stock
Preferred Class B [Member]
STOCKHOLDERS' EQUITY:
Preferred stock