The Douglas XB-42 Mixmaster was an experimental American bomber aircraft, designed for a high top speed. The unconventional approach was to mount the two engines within the fuselage driving a pair of contra-rotating propellers mounted at the tail in a pusher configuration, leaving the wing and fuselage clean and free of drag-inducing protrusions.
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 Douglas Y1B-7 was a 1930s American bomber aircraft. It was the first US monoplane given the B- 'bomber' designation. The monoplane was more practical and less expensive than the biplane, and the United States Army Air Corps chose to experiment with monoplanes for this reason. At the time the XB-7 was ordered, it was being tested by Douglas Aircraft as an observational plane.
The Martin XB-16, company designation Model 145, was a projected heavy bomber designed in the United States during the 1930s.
The Douglas XB-19 was a four-engined, piston-driven heavy bomber produced by the Douglas Aircraft Company for the United States Army Air Forces (USAAF) during the early 1940s. The design was originally given the designation XBLR-2. It was the largest bomber built for the USAAF until 1946, with the Convair B-36 surpassing it in size.
The Boeing Y1B-20 was designed as an improvement on the Boeing XB-15. It was slightly larger than its predecessor, and was intended to use much more powerful engines. It was presented to the Army in early 1938, and two orders were placed soon after. The order was reversed before construction began.
The Lockheed XB-30 was the design submitted by Lockheed after the request by the United States Army Air Forces for a very heavy bomber, the same request that led to the Boeing B-29 Superfortress, the Douglas XB-31 and Consolidated B-32 Dominator.
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 Nakajima G8N Renzan was a four-engine long-range bomber designed for use by the Imperial Japanese Navy. The Navy designation was "Type 18 land-based attack aircraft" (十八試陸上攻撃機); the Allied code name was "Rita".
The Boeing XB-39 Superfortress was a United States prototype bomber aircraft, a single example of the B-29 Superfortress converted to fly with alternative powerplants. It was intended to demonstrate that the B-29 could still be put into service even if the first choice of engine, the air-cooled Wright R-3350 radial engine, ran into development or production difficulties.
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 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.
Boeing XB-55 was a proposed Boeing aircraft designed to be a strategic bomber. The XB-55 was intended to be a replacement for the Boeing B-47 Stratojet in United States Air Force (USAF) service.
The Allison V-3420 was a large experimental piston aircraft engine, designed in 1937 by the American Allison Engine Company.
The Lockheed Altair was a single-engined sport aircraft produced by Lockheed Aircraft Limited in the 1930s. It was a development of the Lockheed Sirius with a retractable undercarriage, and was the first Lockheed aircraft and one of the first aircraft designs with a fully retractable undercarriage.
The Nakajima G5N Shinzan was a four-engined long-range heavy bomber designed and built for the Imperial Japanese Navy prior to World War II. The Navy designation was "Experimental 13-Shi Attack Bomber"; the Allied code name was "Liz".
The Tachikawa Ki-74 was a Japanese experimental long-range reconnaissance bomber of World War II. A twin-engine, mid-wing monoplane, it was developed for the Imperial Japanese Army Air Service but never deployed in combat. The Ki-74 was designed for high altitude operation with a pressurized cabin for its crew.
The Douglas DC-8 was an American piston-engined airliner project by Douglas Aircraft. A concept developed more than a decade before the DC-8 jetliner, the piston-engined DC-8 was to have propellers in the tail, an idea first used at Douglas by Edward F. Burton on a fighter project. The airliner project was canceled after development costs made it commercially unviable.
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.
