Bristol-Siddeley Pegasus Mk. 5 Turbofan Engine


Display Status:

This object is not on display at the National Air and Space Museum. It is either on loan or in storage.

Collection Item Summary:

The Pegasus turbofan engine was developed under the NATO Mutual Weapons Development Program. The engine ran for the first time in 1959, and flight trials in the Hawker Siddeley P.1127 Kestrel prototypes began in October 1960. The P.1127 became the BAe Harrier, the first operational fixed-wing vertical/short take-off and landing (V/STOL) fighter aircraft. The Pegasus first entered operational service with the Royal Air Force in 1969.

Originally designed by Bristol Siddeley and later manufactured by Rolls-Royce plc, the vectored-thrust engine uses movable nozzles to direct the fan and turbine thrust, giving the aircraft V/STOL capability. In service for the U.S. Marine Corps, the engine is given the designation F402.

The unique Pegasus engine powers all versions of the Hawker Siddeley Harrier multi-role military aircraft. Rolls-Royce licensed Pratt & Whitney to build the Pegasus for US built versions. However Pratt & Whitney never completed any engines, with all new build being manufactured by Rolls-Royce in Bristol, England.

Collection Item Long Description:


Circa 1960s

Inventory Number


Physical Description

  • Type: Turbofan, vectored thrust VTOL engine, 4 swivel exhausts
  • Thrust: 68,944 N (15,500 lb) at take-off
  • Compressor: 2-stage front fan, bypass; 7-stage axial
  • Combustor: Cannular
  • Turbine: 3-stage axial
  • Weight: 975 kg (2,150 lb)

Credit Line

Transferred from the U.S. Air Force, Wright-Patterson AFB, Ohio

Country of Origin

United Kingdom


Steel, Aluminum, Rubber, Paint, Inconel, Stainless Steel, Titanium, Magnesium, Cadmium plating


Length 251 cm (98.8 in.), Diameter 121.9 cm (48 in.)

Data Source

National Air and Space Museum

Restrictions & Rights

Do not reproduce without permission from the Smithsonian Institution, National Air and Space Museum


PROPULSION-Turbines (Jet)