Lockheed XP49, Successor to the P-38 Lightning

In 1939, the USAAC issued a contest for a twin-engine heavy interceptor aircraft that intended to use the new Pratt & Whitney X-1800 engine. Two proposals were accepted for prototypes construction as the Lockheed XP-49 and the Grumman XP-50. The XP-49 was very similar in visual appearance to the P-38. In fact the XP-49 was an entirely new design and engineering that featured a pressure cabin and stronger undercarriage. In 1940, both the USAAC and Lockheed came to realize that the X-1800 engine would be seriously overpowered, it was decided to substitude a experimental Continental XI-1430 engines. The single prototype was completed and first flown in 1942. The preliminary flight data showed that performance of the XP-49 was not sufficiently better than the production P-38, and with the cancellation of the powerplants, consideration of quantity production was therefore abandoned. Even the USAAC decided not to proceed with production of the XP-49, the aircraft testing continued at Wright Firled until it was finally scrapped in 1946.