We had an engine overspeed on startup on R44 Raven2 ,normal cold start throttle closed,RPM went skyhigh .
Markings on fan nut out of line, technical intervention required.
Next on the same aircraft , cold engine starts the engine fires very good but when selecting clutch switch engine stops even before there is any movement of the blades.
Today on the same helicopter on warm start the RPM went very high again with throttle closed ,governor off,overspeed was just avoided.
Does anybody had simular experiences?