Engine failure during rescue
My symphathie to the families affected by this event.
The A119 uses a Electronic Engine Control (EEC) system for engine start and engine speed control when the throttle is in the normal flight idle position. There is a Mechanical back-up which is controlled by the beep (like the B206). The throttle is on the collective (same as B206). Also the throttle can be opened beyond normal flight idle in case of fuel flow difficulties. The rpm could have been controlled (and this is my understanding) by winding off enough throttle to contain the run away up situation. However, and this is a BIG however, there is nothing in the flight manual to comment on this situation other than reccommending going to Manual Over-ride system (MAN) and using the throttle, should fluctuations in engine rpm be experienced..
The EEC (Electronic Engine Control) fitted to the A119 is 'not' a FADEC system. It uses mechanical inputs to assist in engine speed control.