Keith,
Just for your info, the Aerospatiale / Westland Gazelle series has no free turbine. Instead it has a centrifugal clutch and an overrun freewheel device. The engine is normally started with the rotor brake on. The brake is then released and the throttle is advanced to the "Fly" position. Once the rotor is brought up to speed the engine is effectively "constant speed" and very well it works too.
