Mar 15, 2011
Accident
Substantial Chandler, AZ
InjuriesNone
Phase of Flight-
ConditionsVMC
OperationFAR 091
Probable Cause
A design modification that changed the fasteners and components used to attach the main rotor drive pulley to the engine, which resulted in fatigue failure of those fasteners and a complete loss of power to the main rotor.
NTSB WPR11LA167