The smallish XP-46 was to be the answer for the deficiencies encountered in the P-40 Warhawk. With production of the P-40 Warhawk in full swing, designers at Curtiss had sold the idea of a more powerful successor to the US Army Air Corps, to which two prototypes were ordered on 29 September 1939. The design was to be powered by an Allison liquid-cooled engine of 1,150 horsepower fitted into a small frame. Armament – proposed but never fitted to either prototype – was consist of eight 0.30 caliber machine guns mounted in the wings with an additional two 0.50 caliber systems in the nose.
The US Army ordered one XP-46 and one XP-46A, the XP-46A without armament to expedite the testing programme. Both were powered by the 857kW Allison V-1710-39 inline engine. The XP-46A flew first on 15 February 1941 and both machines were being tested by the time of Pearl Harbor.
The XP-46 and XP-46A had moderately good performance except for their limited range of 523km. They were heavier and costlier than the P-40D, however, and seemed to lack ‘stretching’ potential for further development. The two airframes were markedly different from each other in detail, especially in cockpit layout, the XP-46 being viewed by pilots as cramped and uncomfortable, a ‘sweatbox’.
By the time the second prototype had flown as the XP-46A, the aircraft was already showing clear signs of never matching even the P-40. The XP-46 proved to be slow-responding for a fighter and the 400mph speed was never close to being reached. The samples were later scrapped.
The Curtiss XP 46 produced data which was made available to North American in the design of the P 51 Mustang.
XP-46
Engine: 1 x Allison V-1710-39, 1,150hp / 857kW
Length: 30.18ft (9.2m)
Wingspan: 34.45ft (10.50m)
Height: 12.99ft (3.96m)
Maximum Speed: 355mph (571kmh; 308kts)
Maximum Range: 325miles (523km)
Rate-of-Climb: 2,000ft/min (610m/min)
Service Ceiling: 27,999ft (8,534m)
Crew: 1
Hardpoints: 0
Empty Weight: 5,624lbs (2,551kg)
Maximum Take-Off Weight: 7,663lbs (3,476kg)
XP-46A
Engine: 1 x Allison V-1710-39, 1,150hp / 857kW
Take-off weight: 3320 kg / 7319 lb
Empty weight: 2550 kg / 5622 lb
Wingspan: 10.46 m / 34 ft 4 in
Length: 9.19 m / 30 ft 2 in
Height: 3.96 m / 12 ft 12 in
Wing area: 19.32 sq.m / 207.96 sq ft
Max. speed: 571 km/h / 355 mph
Ceiling: 8990 m / 29500 ft
Range: 523 km / 325 miles
All Aero 