In 1939, the U.S. Army issued Circular Proposal 39-775 for new fighters that could utilize new engines. Of the four companies that submitted designs, Grumman submitted Design 41 which was largely based on Design 34 (XF5F-1) but would utilize two Wright R-1820 radial engines. Although Lockheed’s design was deemed more favorable, the Army wanted Grumman to continue revising Design 41 as a backup in case Lockheed’s proposal ran into hiccups. Grumman’s resubmission, Design 45, was later given the designation XP-50. The XP-50 was fitted with two Wright R-1820-67/69 radial engines which produced 1,200 hp with the help of turbosuperchargers. The XP-50 was promising in test flights until a turbosupercharger explosion led to the loss of the prototype. The XP-50 project was then canceled.

Introduced as a premium aircraft in Update 1.31, the XP-50 is an extremely capable aircraft. With the help of an airspawn, the XP-50 can reach heights well above enemy aircraft with ease. Although it is quite manoeuvrable, at higher speeds the XP-50 struggles with compression. Players must be careful when diving for opponents, especially with how quickly the XP-50 gains speed and the lack of airbrakes. The XP-50 also has two 20 mm cannons and two 12.7 mm machine guns mounted in the nose. However, the cannons are greatly limited in their ammo pool. Nonetheless, the XP-50 is a great plane for beginners to practice energy fighting and ammo conservation.