The Curtiss XP-71 was a design for a very heavy escort fighter, designed to support long range bombers. Two prototypes were ordered, but the project was cancelled before either of them had been completed.
The idea for the XP-71 was suggested by Curtiss in November 1941, before the US entry into the war, but after the start of the RAF bombing campaign over Germany, which had already demonstrated how vulnerable bombers were in daylight. At this point no single engine fighter had the sort of range needed to escort the bombers, so Curtiss suggested producing a very large twin engine escort fighter instead.
The XP-71 would have been a rather unusual aircraft. It was to have a wingspan of 82ft 3in. The wings would have been fairly thick, with a tapered leading edge and level training edge. The tail was largely conventional apart from having a small fin below the fuselage. The most unusual feature was that it was to be powered by two turbo-supercharged 3,450hp Prattt & Whitney Wasp Major engines arranged in a pusher configuration, driving contra rotating propellers mounted behind the wings. The nose would have been filled with two 37mm cannon with 60 rounds each and one 75mm cannon with 20 rounds. Its crew of two would have sat in a pressurized cabin mounted in front of the wings, with a bubble canopy. It would have had a tricycle undercarriage.
The XP-71 would have been a very heavy aircraft. Its loaded weight would have been 39,950lb, making it heavier than the B-25H Mitchell! Part of this weight would have come from the massive engines, and part from the 1,940 gallon fuel tank. Despite this massive weight, Curtiss estimated that the P-71 would have a top speed of 425mph at 25,000ft, a landing speed of 97mph, be capable of reaching 25,000ft in only 12.5 minutes and have a service ceiling of 40,000ft. As the aircraft was never actually built, it’s not possible to tell if these were realistic figures, but even if they had been, it probably wouldn’t have been terribly manoeuvrable, making it just as vulnerable to German fighters as the bombers it was meant to protect!
Rather remarkably the Army was actually interested in this design, and gave Curtiss a contract to built two prototypes. However before construction even began they changed their minds, and the aircraft was cancelled. The original contract was given in November 1941 and cancelled early in 1942. It is often suggested that it was ordered in the belief that Britain might be about to fall to the Germans, and cancelled when it became clear that wasn’t the case – if that is the case, then it would have been the German failure outside Moscow that ended the P-71 project!
Engine: Two Prattt & Whitney Wasp Major engines
Power: 3,450hp each
Span: 82ft 3in
Length: 61ft 10in
Empty weight: 31,0660lb
Gross weight: 39,950lb
Max speed: 428mph at 25,000ft
Climb Rate: 12.5 minutes to 25,000ft
Service ceiling: 40,000ft
Range: 3,000 miles
Armament: One 75mm cannon and two 37mm cannon