TRIDAIR HELICOPTERS, the California-based developer of the modified twin-engined Bell 206L LongRanger (or Gemini ST) has received certification for in-flight shutdown of an engine as a normal procedure.
The long-awaited clearance allows operators to switch routinely between single- or twin-engined operation depending on circumstances - a cornerstone of the original Gemini ST concept. Until now, in-flight engine shutdown of one of the helicopter's two engines, which power the rotor through a Soloy combining gearbox, has been limited to emergencies only.
The in-flight shutdown certification, awarded by the US Federal Aviation Administration in January, is not applicable to the 206L-4 TwinRanger, a licence-built version of the Gemini ST made by Bell. The Texas-based helicopter manufacturer revealed at the 1995 Heli-Expo that it had elected not to seek single-engined certification of the TwinRanger (Flight International 15-21 February, 1995).
Source: Flight International