The Curtiss-Wright XP-55 Ascender (company designation CW-24) is a 1940s

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prototype fighter aircraft built by

Curtiss-Wright The Curtiss-Wright Corporation is a manufacturer and services provider headquartered in Davidson, North Carolina, with factories and operations in and outside the United States. Created in 1929 from the consolidation (business), consolidation ...

. Along with the Vultee XP-54 and

Northrop XP-56 The Northrop XP-56 Black Bullet was a unique prototype fighter interceptor built by the Northrop Corporation. It was one of the most radical of the experimental aircraft built during World War II. Ultimately, it was unsuccessful and did not ent ...

, it resulted from

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proposal R-40C issued on 27 November 1939 for aircraft with improved performance, armament, and pilot visibility over existing fighters; it specifically allowed for unconventional aircraft designs. An unusual design for its time, it had a

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configuration, a rear-mounted engine, swept wings, and two vertical tails. Because of its pusher design, it was

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referred to as the "Ass-ender". Like the XP-54, the Ascender was designed for the Pratt & Whitney X-1800 engine, but was re-designed after that engine project was canceled. It was also the first Curtiss fighter aircraft to use

tricycle landing gear Tricycle gear is a type of aircraft undercarriage, or ''landing gear'', arranged in a tricycle fashion. The tricycle arrangement has a single nose wheel in the front, and two or more main wheels slightly aft of the center of gravity. Tricycle ...

Design and development

June 1940, the Curtiss-Wright company received an Army contract for preliminary engineering data and a powered

wind tunnel Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...

model. The designation P-55 was reserved for the project. The USAAC was dissatisfied with the results of these tests. Accordingly, Curtiss-Wright built a flying full-scale model they designated CW-24B. The flying testbed was powered by a Menasco C68-5 inline engine. It had a fabric-covered, welded steel tube

fuselage The fuselage (; from the French ''fuselé'' "spindle-shaped") is an aircraft's main body section. It holds crew, passengers, or cargo. In single-engine aircraft, it will usually contain an engine as well, although in some amphibious aircraft t ...

with a wooden wing. The undercarriage was non-retractable. July 1942, the

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issued a contract for three prototypes under the designation XP-55. Serial numbers were 42-78845 through 42-78847. During this time, the Pratt & Whitney X-1800 H-block

sleeve valve The sleeve valve is a type of valve mechanism for piston engines, distinct from the usual poppet valve. Sleeve valve engines saw use in a number of pre-World War II luxury cars and in the United States in the Willys-Knight car and light truck. T ...

engine was delayed, and was eventually canceled. Curtiss decided to switch to the Allison V-1710 (F16)

liquid-cooled Liquid cooling refers to cooling by means of the convection or circulation of a liquid. Examples of liquid cooling technologies include: * Cooling by convection or circulation of coolant, including water cooling * Liquid cooling and ventilatio ...

inline engine because of its proven reliability. Armament was to be two cannon and two machine guns. During the mock-up phase, engineers switched to the V-1710-95. The 20 mm cannons were also replaced by 0.50 in machine guns. One feature of the XP-55 was a propeller jettison lever inside the cockpit to prevent the pilot from hitting the propeller during bailout. The jettison device was invented by W. Jerome Peterson while working as a design engineer for Curtiss-Wright.

Operational history

The first XP-55 (42-78845) was completed on 13 July 1943 with the same configuration as the final prototype CW-24B. The aircraft made its first flight on 19 July 1943 from the Army's Scott Field near the Curtiss-Wright plant in St Louis, Missouri. The pilot was J. Harvey Gray, Curtiss' test pilot. Testing revealed the takeoff run was excessively long. To solve this problem, the nose

elevator An elevator or lift is a cable-assisted, hydraulic cylinder-assisted, or roller-track assisted machine that vertically transports people or freight between floors, levels, or decks of a building, vessel, or other structure. They ar ...

size was increased and the

aileron An aileron (French for "little wing" or "fin") is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll (or movement arou ...

up-trim was interconnected with the flaps so it operated after the flaps were lowered. November 1943, test pilot Harvey Gray, flying the first XP-55 (S/N 42-78845), was testing the aircraft's stall performance at altitude. Suddenly, the XP-55 inverted into an uncontrolled descent. The pilot was unable to right the airplane, and it fell out of control for before Gray was able to parachute to safety. The aircraft was destroyed. The second XP-55 (S/N 42-78846) was similar to the first, but with a slightly larger nose-elevator, modified elevator-tab systems, and a change from balance tabs to spring tabs on the ailerons. It flew for the first time on 9 January 1944. All flight tests were restricted so the stall-zone was avoided. The third XP-55 (S/N 42-78847) flew for the first time on 25 April 1944. It was fitted with four machine guns, and incorporated some of the lessons from the loss of the first XP-55. Engineers discovered the aircraft's stall characteristics could be improved by the addition of four-foot wingtip extensions, and by increasing the limits of the nose elevator travel. Between 16 September and 2 October 1944, the second XP-55 (42-78846), modified to the standards as the third aircraft, underwent official USAAF flight trials. The performance of the XP-55 was inferior to conventional fighter aircraft. Sealing its fate, by 1944, jet-powered fighters were in development; that terminated development of the XP-55. The third prototype XP-55 (s/n 42-78847) was lost on 27 May 1945 during the closing day of the Seventh War Bond Air Show at the Army Air Forces Fair at Wright Field in

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. After a low pass in formation with a

Lockheed P-38 Lightning The Lockheed P-38 Lightning is an American single-seat, twin piston-engined fighter aircraft that was used during World War II. Developed for the United States Army Air Corps by the Lockheed Corporation, the P-38 incorporated a distinctive twi ...

and a

North American P-51 Mustang The North American Aviation P-51 Mustang is an American long-range, single-seat fighter and fighter-bomber used during World War II and the Korean War, among other conflicts. The Mustang was designed in April 1940 by a team headed by James ...

on each wing, its pilot, William C. Glasgow, attempted a slow roll, but lost altitude and crashed, sending flaming debris into occupied civilian ground vehicles on a highway near the airfield. The crash killed Glasgow and four civilians on the ground.

Aircraft disposition

Air Zoo December 2019 016 (Curtiss XP-55 Ascender)

* 42-78845: crashed during vertical dive on Nov 15, 1943. Pilot bailed out. * 42-78846: on display at the Air Zoo in

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. It is on long-term loan from the Smithsonian's National Air and Space Museum in Washington, D.C. * 42-78847: crashed during air show at Wright Field,

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on May 27, 1945. Pilot killed."XP-55 Ascender/42-78847"
''Joe Baugher's Serial Numbers''. Retrieved: 10 May 2013.