Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Jan. 31, 2023	Apr. 30, 2022
CURRENT ASSETS:
Cash	$ 17,196	$ 12,487
Accounts receivable, net of allowance for doubtful accounts	4,754	3,636
Inventories
Parts and raw materials	5,331	4,722
Work in process	3,994	4,080
Finished goods	50	70
Total inventory, net of allowance	9,375	8,872
Contract asset	2,722	1,470
Prepaid expenses and other current assets	3,907	1,361
Total current assets	37,954	27,826
PROPERTY, PLANT AND EQUIPMENT:
Lease right-to-use assets	3,781	3,240
Construction in progress	0	6,417
Land	4,751	4,751
Building and improvements	47,813	40,962
Aircraft	8,798	8,719
Machinery and equipment	5,345	4,917
Office furniture and fixtures	13,207	11,826
Leasehold improvements	4,032	4,032
Property, Plant, and Equipment and Finance Lease Right-of-Use Asset, before Accumulated Depreciation and Amortization	87,727	84,864
Accumulated depreciation	(26,109)	(23,290)
Total property, plant and equipment	61,618	61,574
SUPPLEMENTAL TYPE CERTIFICATES (net of accumulated amortization of $10,239 at January 31, 2023 and $9,336 at April 30, 2022)	8,625	8,018
OTHER ASSETS:
Other assets (net of accumulated amortization of $12,113 at January 31, 2023 and $11,575 at April 30, 2022)	1,390	1,621
Deferred tax asset, net	1,490	1,770
Total other assets	2,880	3,391
Total assets	111,077	100,809
CURRENT LIABILITIES:
Current maturities of long-term debt	4,814	5,165
Current maturities of lease liability	142	106
Accounts payable	6,672	2,773
Contract liability	4,863	820
Gaming facility mandated payment	1,373	1,630
Compensation and compensated absences	3,006	1,911
Income taxes payable	116	1,049
Other current liabilities	473	211
Total current liabilities	21,459	13,665
LONG-TERM LIABILITIES
Long-term debt, net of current maturities	39,821	43,411
Lease liability, net of current maturities	3,351	2,899
Total long-term liabilities	43,172	46,310
Total liabilities	64,631	59,975
COMMITMENTS AND CONTINGENCIES
STOCKHOLDERS' EQUITY:
Common stock, par value $.01: authorized 100,000,000 shares issued 79,873,572 shares, and outstanding 75,896,050 shares at January 31, 2023 and issued 80,348,572 shares, and outstanding 76,458,146 shares at April 30, 2022	799	803
Capital contributed in excess of par	12,745	12,160
Treasury stock at cost, 3,977,522 shares at January 31, 2023 and 3,890,426 shares at April 30, 2022	(2,137)	(2,077)
Retained earnings	35,039	29,948
Total stockholders' equity	46,446	40,834
Total liabilities and stockholders' equity	111,077	100,809
Preferred Class A [Member]
STOCKHOLDERS' EQUITY:
Preferred stock	0	0
Preferred Class B [Member]
STOCKHOLDERS' EQUITY:
Preferred stock	$ 0	$ 0