Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jan. 31, 2025	Jan. 31, 2024	Jan. 31, 2025	Jan. 31, 2024
REVENUE:
Revenues from customers	$ 21,174	$ 18,960	$ 62,363	$ 55,746
COSTS AND EXPENSES:
Marketing and advertising	885	1,216	2,751	3,854
General, administrative and other	3,914	4,008	12,047	11,290
Total costs and expenses	17,148	15,165	49,947	47,215
OPERATING INCOME	4,026	3,795	12,416	8,531
OTHER INCOME (EXPENSE):
Interest expense	(557)	(615)	(1,660)	(1,869)
Gain on sale of product line	1,040	0	1,040	0
Interest income	125	83	331	199
Total other income	608	(532)	220	2,499
INCOME BEFORE INCOME TAXES	4,634	3,263	12,636	11,030
Gain on sale of airplanes			248	4,169
Gain on sale of land			261	0
PROVISION FOR INCOME TAXES:
Provision for income taxes	1,256	881	3,416	2,978
NET INCOME	$ 3,378	$ 2,382	$ 9,220	$ 8,052
BASIC EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.05	$ 0.03	$ 0.14	$ 0.11
WEIGHTED AVERAGE SHARES USED IN PER SHARE CALCULATION (in shares)	66,960,627	69,634,335	67,861,002	70,984,870
DILUTED EARNINGS PER COMMON SHARE (in dollars per share)	$ 0.05	$ 0.03	$ 0.14	$ 0.11
WEIGHTED AVERAGE SHARES USED IN PER SHARE CALCULATION (in shares)	66,960,627	69,634,335	67,861,002	70,984,870
Professional Services [Member]
REVENUE:
Revenues from customers	$ 9,813	$ 9,941	$ 28,700	$ 28,751
COSTS AND EXPENSES:
Cost of services and products	4,033	4,023	11,834	11,976
Aerospace Products [Member]
REVENUE:
Revenues from customers	11,361	9,019	33,663	26,995
COSTS AND EXPENSES:
Cost of services and products	$ 8,316	$ 5,918	$ 23,315	$ 20,095