XP-55 Ascender (CW-24), was a 1940s United States prototype fighter aircraft built by Curtiss. Along with the XP-54 and XP-56, it resulted from USAAC proposal R-40C issued on 27 November 1939 calling for unconventional aircraft designs. A highly unusual design for its time, it had a canard configuration, a rear mounted engine, swept wings and two vertical tails. Like the XP-54, the Ascender was initially designed for the Pratt & Whitney X-1800 engine and had to be redesigned when that engine project was cancelled. It would also be the first Curtiss fighter aircraft to use tricycle landing gear.
Design and Structure
- Type: Single-seat experimental fighter.
- Wings:
- Configuration: Low-wing cantilever monoplane with sharply swept-back wings.
- Design: Thin laminar-flow wing section with roots originating between the pilot’s cockpit and a pusher engine installation. The fins and rudders are located near the outer extremities of the wings. The trailing-edge inboard of the fins is hinged, with inner sections functioning as flaps and outer sections as ailerons. The structure is all-metal with flush-riveted smooth metal skin.
- Fuselage:
- Design: Symmetrical oval section structure of all-metal construction.
- Control Surfaces:
- Location: Fins and rudders are positioned at the wing extremities. A small horizontal stabilizing surface and elevators are mounted on the nose of the fuselage.
- Landing Gear:
- Type: Retractable tricycle type, with main wheels retracting inwardly into the underside of the wings and the nose wheel retracting backward into the fuselage.
Power Plant
- Engine:
- Model: One 1,275 h.p. Allison V-1710-95 (F23R), a twelve-cylinder Vee liquid-cooled engine.
- Location: Mounted at the aft end of the fuselage, driving a three-blade Curtiss Electric pusher airscrew. The airscrew can be jettisoned in an emergency.
- Additional Features: Air intake is located above and the coolant radiator duct below the engine, both incorporated into rectangular vertical stabilizing surfaces. Main fuel tanks are located in the fuselage.
Accommodation and Armament
- Accommodation:
- Pilot’s Position: The cockpit is located over the leading-edge of the wing roots, featuring a jettisonable canopy.
- Armament:
- Weapons: Equipped with two 20 mm cannon and four .50 cal. machine guns mounted in the nose of the fuselage.
This aircraft design showcases a unique configuration with a rear-mounted engine and pusher propeller, swept wings, and a combination of forward and aft control surfaces, likely for advanced aerodynamic testing and high-speed flight experimentation.