Curtiss P-60

P-60
Curtiss XP-60C in flight, powered by a Pratt & Whitney R-2800 engine driving contra-rotating propellers. Its original intended powerplant, the Chrysler IV-2220, was never installed.
Role	Fighter aircraft
Manufacturer	Curtiss-Wright
First flight	18 September 1941
Retired	22 December 1944
Status	Canceled
Primary user	United States Army Air Forces
Produced	1942-1944
Number built	Five (all converted into new variants)
Program cost	$8.88 million USD
Developed from	Curtiss XP-46

The Curtiss P-60 was a 1940s United States single-engine single-seat, low-wing monoplane fighter aircraft developed by the Curtiss-Wright company as a successor to their P-40. It went through a lengthy series of prototype versions, eventually evolving into a design that bore little resemblance to the P-40. None of these versions reached production.

The initial design contained in proposals to the United States Army Air Corps was for an aircraft based upon the P-40 design but featuring a low drag laminar flow wing, a Continental XIV-1430-3 inverted vee engine, and eight wing-mounted 0.5 in (12.7 mm) machine guns. This proposal was accepted and a contract for two prototypes was issued on 1 October 1940 with the aircraft designated the XP-53.

Within two months the Army Air Corps modified the contract to require the second prototype be completed with a Rolls-Royce Merlin engine in place of the XIV-1430. That aircraft was re-designated XP-60. The airframe design for the XP-60 was modified for the different engine, and the main landing gear was changed from the rearward- retracting P-40 design to a new inward retracting version, which allowed a wider wheelbase and a smooth wing surface when the gear was retracted. This aircraft first flew on 18 September 1941 with a British-built Merlin 28 engine. The XP-53 prototype was then converted into a static test airframe for the XP-60.

Considering delivery delays of quantities of the Packard-built Merlin engines due to its use in other fighters, the use of a turbo-supercharged Allison V-1710-75 engine was considered in its place. Consequently, on 31 October 1941, a contract for 1,900 P-60A fighters using the Allison engine, was awarded.

In the meantime, flight tests of the XP-60 prototype were not progressing smoothly. In addition to landing gear problems, expected top speed was not being met due to shortcomings in the laminar-flow wing surface finish, relatively high radiator drag (compared to the North American P-51 Mustang, which was then flying), and less than specified engine output performance. Consequently, work on the P-60A was stopped on 20 December 1941, when the USAAC recommended that Curtiss concentrate on licence production of Republic P-47 Thunderbolts.

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Wikipedia