The last single seat fighter model of the "Texan/Harvard family".
Continuing development from the NA-50 supplied to Peru, North American kept the basic fuselage but added the T-6 tailplane, changed the wing from swept-back to a more tapered shape, beefed up the engine, and of course added more guns including on an underwing pod to create the NA-68. In 1940 Thailand placed an order for 6 aircraft with the first test flight happening in September 1940. At the same time the Thais also ordered 10 NA-69 two seat light bombers also of the Harvard family.
Politics intervened before the aircraft could be delivered, as the US became concerned with the Thais becoming too close to Japan, and both aircraft orders were impounded and transfered to the USAAC. The NA-68's were impressed as P-64's, but with the very small production run there was not much that could be done with the aircraft, and so they were disarmed and sent to the main USAAC training facility at Santa Ana where they were used as fighter trainers.
One P-64 still survives, and was flown by Paul Poberezny for air displays, and was eventually retired to the EAA museum.
