May 31, 2015
Accident
Substantial Cove, OR
InjuriesNone
Phase of Flight-
ConditionsVMC
OperationFAR 133
Probable Cause
The failure of the engine-to-transmission drive shaft coupling assembly due to a fatigue fracture of one of its attachment bolts, which resulted in a loss of power to the main rotor.
NTSB WPR15LA178