Bristol Siddeley BE.53 Pegasus
Rolls-Royce Pegasus

Bristol Aero-Engines began work on the BE.53 Pegasus in 1958. Since the British government had declared manned combat aircraft to be obsolete, NATO's Mutual Weapons Development Program and Bristol paid for development. Four curved nozzles rotate to provide both thrust and lift.
The engine was designed in tandem with the Hawker P.1127 which first flew in 1960. It is still the only engine of its kind.

Production and development of the Pegasus was continued by Rolls-Royce when Bristol was acquired by that firm in 1966. Over 1,100 engines have been produced.


  • Mk 103: 21,500 lb (95.6 kN)


  • Vectored-thrust turbofan
  • Compressor: three LP and eight HP stages
  • Turbine: two LP and two HP stages
  • Mass flow: 435 lb/sec
  • Pressure ratio: 14

used by

  • British Aerospace Harrier