Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jan. 31, 2022	Apr. 30, 2021
CURRENT ASSETS:
Cash	$ 14,556	$ 22,022
Accounts receivable, net of allowance for doubtful accounts	2,172	1,961
Inventories
Parts and raw materials	4,620	4,829
Work in process	3,960	3,657
Finished goods	69	82
Total inventory, net of allowance	8,649	8,568
Contract asset	1,612	421
Prepaid expenses and other current assets	1,339	1,496
Total current assets	28,328	34,468
PROPERTY, PLANT AND EQUIPMENT:
Lease right-to-use assets	3,099	3,099
Construction in progress	4,539	1,170
Land	4,751	4,751
Building and improvements	39,762	39,747
Aircraft	8,719	9,138
Machinery and equipment	4,738	4,253
Office furniture and fixtures	11,205	10,699
Leasehold improvements	4,032	4,032
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization	80,845	76,889
Accumulated depreciation	(22,568)	(20,519)
Total property, plant and equipment	58,277	56,370
SUPPLEMENTAL TYPE CERTIFICATES (net of accumulated amortization of $8,992 at January 31, 2022 and $8,041 at April 30, 2021)	8,087	8,211
OTHER ASSETS:
Other assets (net of accumulated amortization of $11,363 at January 31, 2022 and $10,886 at April 30, 2021)	1,674	2,872
Deferred tax asset, net	1,710	0
Total other assets	3,384	2,872
Total assets	98,076	101,921
CURRENT LIABILITIES:
Current maturities of long-term debt	5,070	5,972
Current maturities of lease liability	106	107
Accounts payable	2,312	1,893
Contract liability	1,056	5,798
Gaming facility mandated payment	1,341	1,458
Compensation and compensated absences	1,736	1,862
Income taxes payable	1,365	212
Other current liabilities	474	265
Total current liabilities	13,460	17,567
LONG-TERM LIABILITIES
Long-term debt, net of current maturities	43,523	39,816
Lease liability, net of current maturities	2,678	2,759
Deferred tax liability, net	0	400
Total long-term liabilities	46,201	42,975
Total liabilities	59,661	60,542
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Common stock, par value $.01: authorized 100,000,000 shares issued 79,020,382 shares, and outstanding 75,310,459 shares at January 31, 2022 and issued 79,070,382 shares, and outstanding 75,366,749 shares at April 30, 2021	790	790
Capital contributed in excess of par	11,218	16,900
Treasury stock at cost, 3,709,923 shares at January 31, 2022 and 3,703,633 shares at April 30, 2021	(1,913)	(1,909)
Retained earnings	28,320	19,580
Total Butler National Corporation's stockholders' equity	38,415	35,361
Noncontrolling interest in BHCMC, LLC	0	6,018
Total stockholders' equity	38,415	41,379
Total liabilities and stockholders' equity	98,076	101,921
Preferred Class A [Member]
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Preferred Class B [Member]
STOCKHOLDERS' EQUITY:
Preferred stock	$ 0	$ 0