Rolls-Royce Spey
Allison TF41

A scaled down version of the cancelled RB.140 Medway, the RB.163 Spey was designed to power the BAe Trident. The RB.163 was rate at 12,550 lbs or 20,500 lbs thrust with afterburner.
The RB.183 (originally called the Spey Junior) is a simplified engine with lower power ratings.

A Spey derivative was produced by Allison as the TF41


  • RB.163-23: 11,000 lb (48.9 kn) thrust
  • RB.168-20: 12,140 lb (54 kN) thrust
  • RB.183-2: 9,900 lb (44 kN) thrust
  • TF41-A-3: 14,500 lb (64.5 kN) thrust


  •  Two-shaft turbofan
  • 4-stage (5-stage in some versions) LP compressor driven by a 2-stage LP turbine
  • 12-stage HP compressor driven by a 2-stage HP turbine

used by

  • British Aerospace Nimrod
  • Fokker F-28 Fellowship
  • Grumman Gulfstream II
  • Vought A-7 Corsair II