Accident Details
According to the pilot's statement, while ferrying the helicopter to the next field, a loud bang was heard from behind. The cyclic control jerked, the helicopter began to vibrate, and rotor RPM decreased. The pilot increased throttle, but the engine responded as if there was no load on the engine. An autorotation was initiated, but control could not be regained, and the aircraft impacted the terrain.
Investigation Findings
Post-accident investigation revealed that one of two pitch control rod assemblies had fractured between the clevis and turnbuckle. Examination of the fracture surface showed areas of fatigue striations and multiple crack initiation sites on the machined surface. The fracture of the pitch control rod assembly was determined to have caused the loss of control.