The Bell XP-83 was a United States prototype jet escort fighter designed by Bell Aircraft during World War II. It first flew in 1945. As with most early first generation jet fighters, the design was hampered by a relative lack of power. With the rapid advancements in jet technology post-WWII, the XP-83 was soon eclipsed by more advanced designs and it never entered production.
The Curtiss-Wright XF-87 Blackhawk was a prototype American all-weather jet fighter-interceptor, and the company's last aircraft project. Designed as a replacement for the World War II–era propeller-driven P-61 Black Widow night/interceptor aircraft, the XF-87 lost in government procurement competition to the Northrop F-89 Scorpion. The loss of the contract was fatal to the company; the Curtiss-Wright Corporation closed down its aviation division, selling its assets to North American Aviation.
The Curtiss-Wright XP-55 Ascender is a 1940s United States prototype fighter aircraft built by Curtiss-Wright. Along with the Vultee XP-54 and Northrop XP-56, it resulted from United States Army Air Corps 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 canard configuration with a rear-mounted engine, and two vertical tails at end of swept wings. Because of its pusher design, it was satirically referred to as the "Ass-ender". Like the XP-54, the Ascender was designed for the 1,800 hp Pratt & Whitney X-1800 24-Cylinder H-engine, but was redesigned after that engine project was canceled. It was also the first Curtiss fighter aircraft to use tricycle landing gear.
The Consolidated Vultee XP-81 is a development of the Consolidated Vultee Aircraft Corporation to build a single seat, long range escort fighter that combined use of both turbojet and turboprop engines. Although promising, the lack of suitable engines combined with the end of World War II doomed the project.
The Curtiss XP-46 was a 1940s American prototype fighter aircraft. It was a development of the Curtiss-Wright Corporation in an effort to introduce the best features found in European fighter aircraft in 1939 into a fighter aircraft which could succeed the Curtiss P-40, then in production.
The Curtiss P-60 was a 1940s American 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 Curtiss XP-62 was a prototype single-engine interceptor aircraft, that was built for the United States Army Air Forces, by the Curtiss-Wright Corporation. It first flew in 1943.
The Fisher P-75 Eagle was an American fighter aircraft designed by the Fisher Body Division of General Motors. Development started in September 1942 in response to United States Army Air Forces requirement for a fighter possessing an extremely high rate of climb, using the most powerful liquid-cooled engine then available, the Allison V-3420. The program was cancelled after only a small number of prototypes and production aircraft had been completed, as it was no longer required in its original role, could not be quickly deployed, and possessed no significant advantages over aircraft already in production.
The Grumman XP-50 was a land-based development of the shipboard XF5F-1 Skyrocket fighter, entered into a United States Army Air Corps (USAAC) contest for a twin-engine heavy interceptor aircraft. The USAAC placed an order for a prototype on 25 November 1939, designating it XP-50, but it lost the competition to the Lockheed XP-49.
The McDonnell XP-67 "Bat" or "Moonbat" was a prototype for a twin-engine, long-range, single-seat interceptor aircraft for the United States Army Air Forces. Although the design was conceptually advanced, it was beset by numerous problems and never approached its anticipated level of performance. The project was cancelled after the sole completed prototype was destroyed by an engine fire.
The Lockheed XP-49 was an advancement on the P-38 Lightning for a fighter in response to U.S. Army Air Corps proposal 39-775. Intended to use the new 24-cylinder Pratt & Whitney X-1800 engine, this proposal, which was for an aircraft substantially similar to the P-38, was assigned the designation XP-49, while the competing Grumman Model G-46 was awarded second place and designated XP-50.
The Lockheed XP-58 Chain Lightning was an American long-range fighter developed during World War II. Although derived from the successful P-38 Lightning, the XP-58 was plagued by technical problems with its engines that eventually led to the project's cancellation.
The Republic XP-72 was an American prototype fighter-interceptor developed by Republic Aircraft as a progression of the P-47 Thunderbolt design. The XP-72 was designed around the Pratt & Whitney R-4360 Wasp Major 28-cylinder air-cooled radial engine with a supercharger mounted behind the pilot and driven by an extension shaft from the engine. The armament consisted of six .50 caliber (12.7 mm) wing-mounted Browning AN/M2 machine guns and underwing racks for two 1,000 lb bombs; Alternative armament packages included two 37 mm M4 autocannons with four .50 caliber AN/M2s, or four M4 autocannons.
The Republic XP-69 was an American fighter aircraft proposed by Republic Aviation in 1941 in response to a requirement by the United States Army Air Corps for a high-speed fighter. Manufacturers were encouraged to consider unorthodox designs; although the design was ordered as a prototype it was canceled because of delays with the engine that was to power it.
The Vultee XP-54 Swoose Goose was a prototype fighter built by the Vultee Aircraft Company for the United States Army Air Forces (USAAF).
The Curtiss XP-71 was a 1941 American proposal for an exceptionally large heavy fighter design. It was intended to serve as an extreme-range interceptor and escort fighter. While significant progress was made in the design phase, no prototypes were ever built, and the design was abandoned in 1943.
Tucker XP-57 was the designation of a lightweight fighter which was proposed to the United States Army Air Corps (USAAC) in 1940. Nicknamed the "Peashooter", it was developed by the Tucker Aviation Corporation under Preston Tucker, who later became famous for the Tucker '48 Sedan.
The Douglas XP-48 was a small, lightweight fighter aircraft, designed by Douglas Aircraft in 1939 for evaluation by the U.S. Army Air Corps. Intended to be powered by a small inline piston engine, the contract was cancelled before a prototype could be constructed, due to the Army's concerns about the projected performance of the aircraft.
The Ranger V-770 was an American air-cooled inverted V-12 aircraft engine developed by the Ranger Aircraft Engine Division of the Fairchild Engine & Aircraft Corporation in the early 1930s.
The Mitsubishi Ki-83 (キ83) was a Japanese experimental long range heavy fighter designed near the end of World War II. It did not reach production status.
