The Curtiss XP-62 was the heaviest American single-seat fighter to fly during the Second World War, but was underpowered and never progressed beyond the prototype stage.
In 1941 the Army issued a specification for a heavy fighter, to be powered by the new Wright R-3360 eighteen cylinder radial engine with a turbo-supercharger and driving contra-rotating propellers. It was to have a pressurized cabin, be armed with four or eight 20mm cannon, and be capable of 468mph at 27,000ft.
Curtiss began design work early in 1941, and on 27 June 1941 they were given a contract to produce one prototype of their new design, as the XP-62 (serial number 41-35873). The new aircraft was a fairly standard looking design, with tapered wings that were level until the undercarriage position, then had dihedral to the tips. The cockpit was faired into the rear fuselage, a sign of its early design and a rather outdated design by the time it actually flew.
Work on the P-62 was disrupted by problems with the new engine. The original contract had called for the prototype to be delivered in September 1942, but the supercharged engine and contra-rotating propellers couldn’t be ready by then. Curtiss suggested completing the aircraft with a standard engine. The army agreed to this, but photographs of the completed aircraft show it with the contra-rotating propellers and it would appear to have been completed with the turbo-supercharged engine. In January 1942 it was clear that the aircraft was going to be too heavy to achieve its target speeds, and the Army suggested that it should be made at least 500lb lighter. Even so, when it did finally fly it had an empty weight of 11,773lb (compared to 10,700lb for the famously bulky P-47 Thunderbolt)
The P-62 was very briefly ordered into production, although it isn’t entirely clear why. A contract for 100 P-62s was issued on 25 May 1942, with the aircraft to be delivered from May 1943, even through it was considered to inferior to the P-47, which Curtiss was also building. When it became clear that production of the P-62 would come at the cost of some of those P-47s, the Army lost all interest, and the contract was withdrawn on 27 July 1942.
Although there was no longer any interest in placing the P-62 into production, work continued on the prototype, which was already three-quarters finished. The original target for its maiden flight had been fifteen months after the initial contract, so roughly September 1942. However the many changes, combined with delays to the cabin pressurization equipment, meant that the XP-62 didn’t make its maiden flight until 21 July 1943. Even then neither the pressurized cockpit nor the guns had been installed. Work did begin on installed the pressurization equipment, but with very low priority. Eventually all work was cancelled, and the prototype was scrapped in the Autumn of 1944 without flying again.
Performance figures from Curtiss estimates
Engine: Wright R-3350-17 radial engine
Span: 53ft 7.75in
Length: 39ft 6in
Height: 16ft 3in
Empty weight: 11,773lb
Normal loaded weight: 14,660lb
Maximum take-off weight:
Max speed: 448mph at 27,000ft, 358mph at 5,000ft
Climb Rate: 6.9 mins to 15,000ft
Range: 900 miles