Military Wiki
The sole prototype XP-79B.
Role Interceptor
Manufacturer Northrop Corporation
Designer Jack Northrop
First flight 12 September 1945
Retired 12 September 1945
Status Prototype
Primary user United States Army Air Forces
Number built 1

The Northrop XP-79 was an ambitious design for a flying wing fighter aircraft, designed by Northrop. It had several notable design features; among these, the pilot would operate the aircraft from a prone position, permitting the pilot to withstand much greater g-forces in the upward and downward direction with respect to the plane – and welded magnesium monocoque structure instead of riveted aluminum.

Design and development

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]


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.

Specifications (XP-79B)

Data from[citation needed]

General characteristics

  • Crew: 1
  • Length: 14 ft 0 in (4.27 m)
  • Wingspan: 38 ft 0 in (11.58 m)
  • Height: 7 ft 6 in (2.29 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


  • 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


  • Guns: 4 × .50-cal (12.7 mm) machine guns (never fitted)

See also


  1. Winchester 2005, p. 150.
  2. Winchester 2005, p. 151.
  • Jenkins, Dennis R. and Tony R. Landis. Experimental and Prototype U.S. Air Force Jet Fighters. North Branch, Minnesota: Specialty Press, 2008. ISBN 978-1-58007-111-6.
  • Pape, Garry and John Campbell. Northrop Flying Wings. Atglen, Pennsylvania, Schiffer Publications, 1995, ISBN 0-88740-689-0.
  • Winchester, Jim. The World's Worst Aircraft: From Pioneering Failures to Multimillion Dollar Disasters. London: Amber Books Ltd., 2005. ISBN 1-904687-34-2.

External links

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