Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jul. 30, 2018	Apr. 30, 2018
CURRENT ASSETS:
Cash	$ 7,545	$ 7,353
Accounts receivable	3,225	3,107
Income tax receivable, net	31	219
Inventories
Parts and raw materials	6,262	5,858
Work in process	1,222	1,234
Finished goods	26	27
Total inventory, net of allowance	7,510	7,119
Prepaid expenses and other current assets	1,440	978
Total current assets	19,751	18,776
PROPERTY, PLANT AND EQUIPMENT:
Land and building	5,232	5,232
Aircraft	6,157	6,157
Machinery and equipment	3,942	3,922
Office furniture and fixtures	6,724	6,658
Leasehold improvements	4,032	4,032
	26,087	26,001
Accumulated depreciation	(15,983)	(15,725)
Total property, plant and equipment	10,104	10,276
SUPPLEMENTAL TYPE CERTIFICATES (net of accumulated amortization of $5,384 at July 31, 2018 and $5,164 at April 30, 2018)	6,518	6,597
OTHER ASSETS:
Deferred tax asset	193	193
Other assets (net of accumulated amortization of $8,485 at July 31, 2018 and $8,213 at April 30, 2018)	5,317	5,589
Total other assets	5,510	5,782
Total assets	41,883	41,431
CURRENT LIABILITIES:
Promissory notes	1,676	2,387
Current maturities of long-term debt	1,555	1,612
Accounts payable	1,927	2,215
Customer deposits	2,736	1,396
Gaming facility mandated payment	937	1,219
Compensation and compensated absences	1,258	1,439
Other current liabilities	223	162
Total current liabilities	10,312	10,430
LONG-TERM DEBT, NET OF CURRENT MATURITIES	1,389	1,735
Total liabilities	11,701	12,165
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Common stock, par value $.01: authorized 100,000,000 shares issued 66,196,854 and outstanding 64,718,040 shares at July 31, 2018 and issued 66,196,854 and outstanding 64,743,317 shares at April 30, 2018	662	662
Capital contributed in excess of par	14,231	14,231
Treasury stock at cost, 1,478,814 shares at July 31, 2018 and 1,453,537 shares at April 30, 2018	(957)	(951)
Retained earnings	10,569	10,060
Total stockholders' equity Butler National Corporation	24,505	24,002
Noncontrolling interest in BHCMC, LLC	5,677	5,264
Total stockholders' equity	30,182	29,266
Total liabilities and stockholders' equity	41,883	41,431
Preferred Class A [Member]
STOCKHOLDERS' EQUITY:
Preferred stock
Preferred Class B [Member]
STOCKHOLDERS' EQUITY:
Preferred stock