The McDonnell XF-88 Voodoo was a long-range, twinjet fighter aircraft with swept wings designed for the United States Air Force. Although it never entered production, its design was adapted for the subsequent supersonic F-101 Voodoo.
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 Two prototypes were completed, but the dedicated torpedo bomber was becoming an outdated concept, and with the end of World War II, the type was deemed unnecessary and cancelled.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 Douglas X-3 Stiletto is a 1950s United States experimental jet aircraft with a slender fuselage and a long tapered nose, manufactured by the Douglas Aircraft Company. Its primary mission was to investigate the design features of an aircraft suitable for sustained supersonic speeds, which included the first use of titanium in major airframe components. Douglas designed the X-3 with the goal of a maximum speed of approximately 2,000 mph (3,200 km/h), but it was seriously underpowered for this purpose and could not even exceed Mach 1 in level flight. Although the research aircraft was a disappointment, Lockheed designers used data from the X-3 tests for the Lockheed F-104 Starfighter which used a similar trapezoidal wing design in a successful Mach 2 fighter.
The Douglas A2D Skyshark was an American turboprop-powered attack aircraft built by the Douglas Aircraft Company for the United States Navy. The program was substantially delayed by engine reliability problems, and was canceled because more promising jet attack aircraft had entered development and the smaller escort carriers the A2D was intended to utilize were being phased out.
The Kyūshū Q1WTōkai was a land-based anti-submarine patrol bomber aircraft developed for the Imperial Japanese Navy in World War II. The Allied reporting name was Lorna. Although similar in appearance to the German Junkers Ju 88 medium bomber, the Q1W was a much smaller aircraft with significantly different design details.
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 Douglas XA-2 was an American prototype attack aircraft converted from a Douglas O-2 observation aircraft in the spring of 1926 by Douglas Aircraft. Only one prototype aircraft was built and the type was not ordered into production.
The Hughes XH-17 "Flying Crane" was the first helicopter project for the helicopter division of Hughes Aircraft Company. The XH-17, which had a two-bladed main rotor system with a diameter of 134 feet, still holds the world record for flying with the largest rotor system. It was capable of flying at a gross weight of more than 50,000 pounds (23,000 kg), but proved too inefficient and cumbersome to be mass-produced beyond the prototype unit.
The Lockheed XV-4 Hummingbird was a U.S. Army project to demonstrate the feasibility of using VTOL for a surveillance aircraft carrying target-acquisition and sensory equipment. It was designed and built by the Lockheed Corporation in the 1960s, one of many attempts to produce a V/STOL vertical take off/landing jet. Both prototype aircraft were destroyed in accidents.
The Douglas O-43 was a monoplane observation aircraft used by the United States Army Air Corps.
The Breguet 941 is a French four-engine turboprop short takeoff and landing (STOL) transport aircraft developed by Breguet in the 1960s. Although widely promoted, both by Breguet in France and by McDonnell Aircraft and McDonnell Douglas in the United States, it was not built in large numbers; only one prototype and four production aircraft were built.
The Fairchild J83 turbojet was developed starting in 1955 to power cruise missiles used as un-armed decoys for bomber aircraft. The engine's development was terminated in November 1958.
The Westinghouse J34, company designation Westinghouse 24C, was a turbojet engine developed by Westinghouse Aviation Gas Turbine Division in the late 1940s. Essentially an enlarged version of the earlier Westinghouse J30, the J34 produced 3,000 pounds of thrust, twice as much as the J30. Later models produced as much as 4,900 lb with the addition of an afterburner. It first flew in 1947. The J46 engine was developed as a larger, more powerful version of Westinghouse's J34 engine, about 50% larger.
The Douglas XP3D was a prototype American patrol flying boat of the 1930s. A twin-engined high-winged monoplane, the P3D was produced by the Douglas Aircraft Company to equip the US Navy's Patrol squadrons, but despite meeting the Navy's requirements, the rival Consolidated PBY was preferred owing to a lower price.
The Lockheed Model 34 Big Dipper was an American two-seat monoplane, designed and built by Lockheed at Burbank for research into the company's potential entry into the civil lightplane and military light utility aircraft market. Only one was built, and following its loss in an accident the program was abandoned.
The Douglas XO2D-1 was a prototype American observation floatplane of the 1930s. It was a single engined biplane intended to be launched by aircraft catapult from ships of the United States Navy, but only one was built, the production contract going to Curtiss for the SOC Seagull.
The Lockheed Model 33 Little Dipper, also known as Air Trooper, was an American single-seat monoplane, designed by John Thorp and built by Lockheed at Burbank, California. Flown in 1944 and offered to the Army as a "flying motorcycle", it was evaluated as a potential entry for Lockheed into the civilian market, but the program was cancelled before the second prototype was completed.
The Douglas Cloudster II was an American prototype five-seat light aircraft of the late 1940s. It was of unusual layout, with two buried piston engines driving a single pusher propeller. Only a single example was built, which flew only twice, as it proved too expensive to be commercially viable.
The McDonnell XHCH was a 1950s aerial crane helicopter proposal for the United States Navy by the McDonnell Corporation.
The McDonnell 120 Flying Crane, also V-1 Jeep, was a lightweight utility flying crane helicopter designed and built by the McDonnell Aircraft Corporation during the 1950s. The open frame fuselage supported the three gas-producers and main rotor mast, with a small single-seat cockpit in the nose, which was originally open, but later enclosed.
