Lockheed XP-49

The Lockheed XP-49, company Model 522, was Lockheed's advance on the P-38 Lightning, built in response to United States Army Air Corps proposal 39-775 and substantially similar to the P-38. It was meant to use the new 24-cylinder Pratt and Whitney X-1800 engine, and the competing Grumman Model G-46 was awarded second place as the XP-50. Ordered in October 1939 and approved on 8 January 1940, it was to feature a pressurized cockpit and an armament of two 20 mm cannon and four .50 inch machine guns. Two months into the contract the Continental XI-1430 was substituted for the X-1800. The prototype first flew on 11 November 1942, force-landed on 1 January 1943 when the port landing gear failed to lock down, and flew again on 16 February 1943. Its performance was not enough better than the production P-38 to justify disrupting the production line, so quantity production was abandoned and Lockheed turned to improving the P-38 instead.