The Lockheed XP-49 (company Model 522) was an advancement on the P-38 Lightning for a fighter in response to U.S. Army Air Corps proposal 39-775. Intended to use the new twenty-four cylinder Pratt & Whitney X-1800 engine, this proposal, which was for an aircraft substantially similar to the P-38, was assigned the designation XP-49, while the competing Grumman Model G-46 was awarded second place and designated XP-50.
Ordered in October 1939 and approved on January 8
, the X-1800-powered XP-49 would feature a pressurized cockpit and armament of two 20 mm cannon and four 0.5 inch (12.7 mm) machine guns. However, after two months into the contract a decision was made to substitute the Continental XI-1430-1
(or IV-1430) twelve cylinder liquid-cooled inverted vee engines for the X-1800. The XP-49 first flew on November 11
. A crash landing in early January 1943
occurred when the port landing gear failed to lock down due to a combined hydraulic and electric failure, and the XP-49 flew again on February 16
, 1943 after repairs were made. The preliminary flight data showed that performance of the XP-49 was not sufficiently better than the production P-38, and with a questionable future for the XI-1430 engine, to warrant disruption of the production line to introduce the new model aircraft. Consideration of quantity production was therefore abandoned.
The aircraft was flown to Wright Field, and after various problems further work on the XP-49 was halted.
- Green, William. War Planes of the Second World War, Volume Four: Fighters. London: MacDonald & Co. (Publishers) Ltd., 1961 (Sixth impression 1969). ISBN 0-356-01448-7.
- Green, William and Swanborough, Gordon. WW2 Aircraft Fact Files: US Army Air Force Fighters, Part 2. London: Macdonald and Jane's Publishers Ltd., 1978. ISBN 0-354-01072-7.