In 1942, John K. Northrop conceived the XP-79 as a high-speed rocket-powered flying-wing fighter aircraft.
In January 1943, a contract for three prototypes designation XP-79 was issued by the United States Army Air Forces.
To test the radical design, glider prototypes were built. One designated MX-324 was towed into the air on 5 July 1944 by a P-38 making it the first US-built rocket-powered aircraft to fly.[1]
Originally, it was planned to use a 2,000 lbf (9 kN) thrust XCALR-2000A-1 "rotojet" rocket motor supplied by Aerojet that used monoethyl aniline and red fuming nitric acid; because of the corrosive and toxic nature of the liquids, the XP-79 was built using a welded magnesium alloy monocoque structure (to protect the pilot if the aircraft was damaged in combat) with a ⅛ in (3 mm) skin thickness at the trailing edge and a ¾ in (19 mm) thickness at the leading edge. However, the rocket motor configuration using canted rockets to drive the turbopumps was unsatisfactory and the aircraft was, subsequently fitted with two Westinghouse 19-B (J30) turbojets instead. This led to changing the designation to XP-79B. After the failure of the rocket motor, further development of the first two prototypes, ended.
The pilot controlled the XP-79 through a tiller bar and rudders mounted below; intakes mounted at the wingtips supplied air for the unusual bellows-boosted ailerons.[2]
[edit] Testing
The XP-79B (after delays because of bursting tires and brake problems on taxiing trials on the Muroc dry lake) was lost on its first flight 12 September 1945. While performing a slow roll 15 minutes into the flight, control was lost for unknown reasons. The nose dropped and the roll continued with the aircraft impacting in a vertical spin. Test pilot Harry Crosby attempted to bail out but was struck by the aircraft and fell to his death. Shortly thereafter, the project was cancelled.
[edit] Specifications (XP-79B)
Data from[citation needed]
General characteristics
Crew: 1
Length: 14 ft 0 in (4.27 m)
Wingspan: 28 ft 0 in (8.54 m)
Height: 7 ft 0 in (2.13 m)
Wing area: 278 ft² (25.8 m²)
Empty weight: 5,840 lb (2,650 kg)
Loaded weight: 8,669 lb (3,932 kg)
Powerplant: 2 × Westinghouse 19B turbojet, 1,150 lbf (5.1kN) each
Performance
Maximum speed: 547 mph (880 km/h)
Range: 993 mi (1,598 km)
Service ceiling: 40,000 ft (12,200 m)
Rate of climb: 4,000 ft/min (1,220 m/min)
Wing loading: 31 lb/ft² (153 kg/m²)
Thrust/weight: 0.27
