The Pratt & Whitney R-4360 Wasp Major is an American 28-cylinder four-row radial piston aircraft engine designed and built during World War II. First run in 1944, at 4,362.5 cu in (71.5 L), it is the largest-displacement aviation piston engine to be mass-produced in the United States, and at 4,300 hp (3,200 kW) the most powerful. It was the last of the Pratt & Whitney Wasp family, and the culmination of its maker's piston engine technology.
The Douglas XTB2D Skypirate was a torpedo bomber intended for service with the United States Navy's Midway- and Essex-class aircraft carriers; it was too large for earlier decks. Two prototypes were completed, but the dedicated torpedo bomber was becoming an outdated concept, and with the end of World War II, the type was deemed unnecessary and cancelled.
The Keystone B-4 was a biplane bomber, built by the Keystone Aircraft company for the United States Army Air Corps.
The Keystone B-5 is a light bomber made by the Keystone Aircraft company for the United States Army Air Corps in the early 1930s. The B-5A was a Keystone B-3A with Wright Cyclone rather than Pratt & Whitney engines.
The Grumman TB2F was a cancelled twin-engined torpedo bomber project, intended as Grumman's successor to the successful TBF Avenger. However, only a mockup was ever constructed.
The North American XB-28 Dragon (NA-63) was an aircraft proposed by North American Aviation to fill a strong need in the United States Army Air Corps for a high-altitude medium bomber. It never entered production, with only two prototypes being built.
The Douglas XB-31 was the design submitted by Douglas after the request by the United States Army Air Forces for a very heavy bomber aircraft, the same request that led to the Boeing B-29 Superfortress, Lockheed XB-30, and Consolidated B-32 Dominator.
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 Martin Model 167 Maryland was an American medium bomber that first flew in 1939. It saw action in World War II with France and the United Kingdom.
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.
The Northrop YA-13 was an attack version of the Northrop Gamma type aircraft. After receiving an engine change, the aircraft was redesignated XA-16.
The Vultee V-11 and V-12 were American stressed-skin monocoque monoplane attack aircraft of the 1930s. Developed from the Vultee V-1 single-engined airliner, the V-11 and V-12 were purchased by several nations for their armed forces, including China, who used them in combat against Japanese forces in the Second Sino-Japanese War. The United States Army Air Corps purchased seven V-11s as the YA-19 in the years before World War II, testing them to gather data to compare against twin engine light attack aircraft.
The Stearman XA-21 was a competitor in a United States Army Air Corps competition for a twin-engined attack aircraft which led to the Douglas A-20 Havoc, Martin A-22 Maryland and North American B-25 Mitchell.
The Vultee XA-41 was originally ordered as a dive bomber. After combat experience led the Army Air Corps to believe dive-bombers were too vulnerable to enemy fighters, the contract was amended to change the role to low-level ground attack. Although the XA-41 was a potent weapons system, the design was overtaken by more advanced technology, and never entered production.
The Boeing B-54 was an American strategic bomber designed by Boeing for use by the United States Air Force. Derived from the YB-50C Superfortress, construction of the prototype was canceled before completion, and the aircraft was never flown.
The Boeing P-29 and XF7B-1 were an attempt to produce a more advanced version of the highly successful P-26. Although slight gains were made in performance, the U.S. Army Air Corps and U.S. Navy did not order the aircraft.
The Curtiss XBTC was a prototype single-seat, single-engined torpedo/dive bomber developed during World War II for the United States Navy. Four aircraft were ordered, powered by two different engines, but the two aircraft to be fitted with the Wright R-3350 radial engine were cancelled in late 1942, leaving only the pair using the Pratt & Whitney R-4360 radial. By this time, Curtiss Aircraft was overwhelmed with work and the Navy gave the XBTC-2 prototypes a low priority which delayed progress so the first flight did not take place until the beginning of 1945. One aircraft crashed in early 1947 and the other was disposed of later that year.
The Boeing AT-15 was an American twin-engined bomber crew trainer designed and built by Boeing's Wichita Division. Only two prototypes, designated XAT-15, were built. Plans to build over 1,000 were cancelled on the United States' entry into the Second World War.
The Macchi MB.323 was an Italian single-engine basic training monoplane designed and built by Macchi. No orders were placed and only a prototype was built.
The Grumman G-132 was an unbuilt aircraft designed by Grumman in the 1950s. The design was initiated to meet a requirement of the United States Navy (USN) for an anti-submarine warfare seaplane.
