The Douglas XB-43 was the first US jet bomber and was produced by fitting jet engines to the earlier Douglas XB-42 Mixmaster.
The XB-42 was a radical design for a long range twin engined bomber in which the engines were carried inside the fuselage and powered contra-rotating pusher propellers mounted behind the tail. The first prototype B-42 was ready by May 1942, and performed impressively in its trials, but it was already clear that the new turbojet engines would probably make it obsolete. During 1943 Douglas suggested fitting turbojet engines under the wings of the B-42 and this was tried out after the war. In October 1943 Douglas and the Air Materiel Command also examined the feasibility of installed turbojet engines in place of the internal piston engines of the B-42 design.
It quickly became clear that this idea was entirely feasible, and on 31 March 1944 the original XB-42 contract was modified to include the development of two jet-powered XB-43 aircraft.
The original B-42 contract had covered two flying prototypes and one stress test airframe. In order to speed up the development of the B-43 this airframe was used for the first prototype. The Allison engines were removed and two General Electric TG-180/ J35-GE-3 engines were installed instead. Long tail-pipes transferred their output to the tail, and new air intakes were added by the sides of the cockpit. A two seat pressurized cockpit was installed. The B-42 had a cross-shaped tail with a small vertical tail mounted below the fuselage to protect the props in a belly landing. With the removal of the propellers this lower part of the tail could also be removed. The upper fin was enlarged to compensate for this change. The B-43 was otherwise rather similar to the B-42, with a clean fuselage and thin mid-mounted wings.
The maiden flight of the XB-43 was delayed by problems with the turbojets, detected during ground tests in October 1945. The aircraft made its first flight on 17 May 1946, and performed fairly well. However by this time the USAAF had already decided to focus on the North American B-45 four engined jet bomber, and so no production orders were placed for the B-43. Some problems did occur during the flight tests, most importantly a relative lack of power.
The second aircraft, which was completed in May 1947, was used as an engine test bed. It kept one J35 engine, but the second engine was replaced with a General Electric J47. This aircraft remained in use until 1953, and then became part of the collection of the Smithsonian National Air & Space Museum
Engine: Two General Electric J35-GE-3
Power: 4,000lb thrust (per or each?)
Span: 71ft 2in
Length: 51ft 5in
Height: 24ft 3in
Empty weight: 22,890lb
Gross weight: 40,000lb
Max speed: 507mph
Climb Rate: 2,470ft per minute
Service ceiling: 38,500ft
Range: 2,500 miles at 420mph
Bomb load: 8,000lb (planned)