Jul 11, 2000
Accident
Substantial CUSICK, WA
Injuries1 serious
Phase of Flight-
ConditionsVMC
OperationFAR 133
Probable Cause
The termination of power to the main rotor system as a result of the malfunction of the free-wheeling sprag clutch assembly, followed by the torsional overload separation of the engine adapter shaft. Factors include trees in the area where the emergency descent was attempted.
NTSB SEA00LA129