General Electric T58
de Havilland Gnome

In 1953 the U.S. Navy asked for a helicopter turboshaft to weigh 400 lbs and deliver 800 hp. GE's prototype T58 first ran in 1955 weighing 250 lbs and delivered 1,050 hp. Two T58s powered the first jet helicopter in the U.S., a modified HSS-1, in 1957. In 1959, the civil CT58 was the first jet helicopter engine certified by the FAA.
Production ended in 1984 but not before the T58 became the basis for the LM100 gas generator and was license built by de Havilland (now Rolls-Royce) as the Gnome, Alfa Romeo and IHI.


  • CT58-GE-8: 1,250 hp (932 kW)
  • T58-GE-10: 1,400 hp (1044 kW)
  • Gnome Mk 110: 1,350 hp (1007 kW)


  • Turboshaft
  • Compressor: 10-stage axial
  • Four variable stators Turbine: 2-stage LP/2-stage HP
  • Mass flow: 12 - 14 lbs/sec
  • Pressure ratio: 8

used by

  • Sikorsky SH-3 Sea King
  • Sikorsky HH-52 Seaguard
  • Westland Wessex