The Boeing XB-15 was a United States bomber aircraft designed in 1934 as a test for the United States Army Air Corps (USAAC) to see if it would be possible to build a heavy bomber with a 5,000 mi (8,000 km) range. For a year beginning in mid-1935 it was designated the XBLR-1. When it first flew in 1937, it was the most massive and voluminous airplane ever built in the US. It set a number of load-to-altitude records for land-based aircraft, including carrying a 31,205 lb (14,154 kg) payload to 8,200 ft (2,500 m) on 30 July 1939.
The Boeing XPBB-1 Sea Ranger was a prototype twin-engined flying boat patrol bomber built for the United States Navy. The order for this aircraft was canceled, to free production capacity to build the Boeing B-29, and only a single prototype was completed.
The Boeing XF8B was a single-engine aircraft developed by Boeing during World War II to provide the United States Navy with a long-range shipboard fighter aircraft. The XF8B was intended for operation against the Japanese home islands from aircraft carriers outside the range of Japanese land-based aircraft. Designed for various roles including interceptor, long-range escort fighter, dive-bomber, and torpedo bomber, the final design embodied a number of innovative features in order to accomplish the various roles. Despite its formidable capabilities, the XF8B-1 never entered series production.
The Vought SBU-1 Corsair was a two-seat, all-metal biplane dive bomber built by Vought Aircraft Company of Dallas, Texas for the US Navy. Its design was based upon the F3U-1 two-seat fighter that was abandoned when the Navy decided not to obtain any more two-seat fighters.
The Boeing YB-9 was the first all-metal monoplane bomber aircraft designed for the United States Army Air Corps. The YB-9 was a much enlarged twin-engine development of Boeing's single-engine Model 200 Monomail commercial transport.
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 Hall XPTBH was a prototype American twin-engined seaplane, submitted to the United States Navy by the Hall Aluminum Aircraft Corporation in response to a 1934 specification for new bomber and scout aircraft. Constructed in an innovative fashion that made extensive use of aluminum, the XPTBH proved successful in flight testing, but failed to win favor with the U.S. Navy. No production contract was awarded, and the single aircraft built served in experimental duties before its destruction in a hurricane during 1938.
The Grumman XTSF was a proposed twin-engine torpedo scout aircraft, designed by Grumman for the United States Navy towards the end of World War II. Based on the design of the Grumman F7F Tigercat fighter, but enlarged and with the addition of a bomb bay, the XTSF was deemed too large for carrier operations, and the project was cancelled before any aircraft were built. Instead, the Navy chose to order the single-engine XTB3F, which became the successful AF Guardian.
The Boeing F2B was a biplane fighter aircraft of the United States Navy in the 1920s, familiar to aviation enthusiasts of the era as the craft of the Three Sea Hawks aerobatic flying team, famous for its tied-together formation flying.
The Douglas T2D was an American twin-engined torpedo bomber contracted by the military, and required to be usable on wheels or floats, and operating from aircraft carriers. It was the first twin-engined aircraft to be operated from an aircraft carrier.
The Lublin R-XX was the Polish torpedo bomber floatplane, designed in the early 1930s in the Plage i Laśkiewicz factory in Lublin. It remained a prototype.
The Fairchild AT-21 was an American World War II specialized bomber crew trainer, intended to train crews in the use of power gun turrets or a gun on a flexible mount, as well as learn to function as a member of a crew. It had a brief career as a training aircraft before modified bombers took over this role.
The Avro Type 557 Ava was a British twin-engined biplane torpedo bomber of the 1920s. It was developed by Avro to meet a requirement for a heavy torpedo bomber for the Royal Air Force but was unsuccessful, only two prototypes being built.
The Curtiss CS was a reconnaissance and torpedo bomber aircraft used by the United States Navy during the 1920s. It was a large single-engine biplane with single-bay unstaggered wings, the design conventional in all respects other than that the lower wing was of greater span than the upper. The CS was built to allow its undercarriage to be quickly and easily interchangeable between wheeled, tailskid undercarriage, and twin pontoons for operation from water. Provision for the carriage of a torpedo was semi-recessed into the underside of the fuselage, blended in behind an aerodynamic fairing. The pilot and gunner sat in tandem open cockpits, while accommodation inside the fuselage was provided for a third crewmember who served as bombardier and radio operator. This station was also provided with a dorsal hatch aft of the gunner's position, and a ventral blister aft of the torpedo recess, which was used for aiming bombs or torpedoes.
The Grumman XSBF, also known by the company designation G-14, was an American biplane scout bomber developed by Grumman Aircraft for the United States Navy during the 1930s. Derived from Grumman's successful "Fifi" fighter, the aircraft was developed at a time when the biplane was giving way to the monoplane. In competition against other aircraft it proved to possess inferior performance in its intended role, and did not enter production. The sole prototype went on to serve as a liaison aircraft, as well as being used in experiments by NACA, before being destroyed in a crash in 1939.
The Martin T3M was an American torpedo bomber of the 1920s. A single-engined three-seat biplane, it became a standard torpedo bomber of the U.S. Navy, operating from both land bases and from aircraft carriers from 1926 to 1932.
The Macchi M.24 was a flying boat designed by Alessandro Tonini and produced by Macchi in Italy during the 1920s. Originally intended as a bomber, it was eventually produced for civilian use as well.
The Boeing Model 64 was an American single engine biplane training aircraft built by Boeing in the 1920s that failed to gain any orders.
The Dewoitine D.750 was a prototype French twin-engined torpedo bomber. It was designed prior to the outbreak of the Second World War to operate from the aircraft carriers of the French Navy, but only a single example was completed, with development ended by France's defeat by Germany in June 1940.
The Curtiss CT-1 model 24, a twin engine torpedo bomber mounted on floats, was first flown in 1921.
