The designator North American P-64 was assigned by the U.S. Army Air Corps to six North American model NA-68 aircraft seized by the US government that were destined for Thailand when that country was invaded by Japanese forces in World War II.
The North American NA-68 was a development by the North American Aviation Company of a simple single seat, low-wing, single engine fighter for export. The design was developed from the model NA-16 experimental basic training aircraft of 1935. The NA-16 evolved into a series of aircraft that were some of the most successful advanced and basic training aircraft produced by any country and was the basic design for single engine fighters for small countries that needed simple aircraft with modern features.
In 1940, the Royal Thai Air Force ordered six aircraft similar to the NA-50A that were designated NA-68. The changes in the NA-68 included a modified landing gear, heavier armament, and redesigned tail surfaces similar to that adopted in later production advanced trainers. These aircraft were en route to Thailand when seized and returned to the United States where they were disarmed, assigned the P-64 designator and used for advanced fighter training.
Another single seat fighter that evolved from the basic NA-16 trainer design is the Australian Commonwealth Aircraft Corporation CA-12 Boomerang fighter.
The only P-64 survivor is one of the six Thai-bound P-64s, that was used for training and liaison, and is now on display in the Eagle Hangar of the EAA AirVenture Museum. One original NA-50 stills survives in Peru where it is displayed next to the Mausoleum of Captain José Quiñones.