Incident Overview
A helicopter engaged in herding horses into a trap was hovering approximately 80 feet above ground level. As the pilot transitioned from hover to forward flight, the rotor rpm began to decay while the engine rpm increased rapidly. The pilot executed an autorotation, resulting in a rapid descent and hard landing.
Damage and Post-Impact Events
The hard landing caused the main landing skids to collapse. The main rotor blades contacted and severed the tail boom. The helicopter came to rest with the engine still running. A wrangler assisted the pilot in turning off the magnetos.
Witness Observations
Several individuals in the area reported hearing the engine sound change from a normal pitch to a high pitch just before the collision. An individual who was video recording the activity captured the engine sound transitioning to a high pitch immediately prior to the sound of the impact.
Post-Accident Inspection
Following wreckage recovery, the engine, transmission, clutch, and freewheeling systems were inspected. No evidence of mechanical failure or malfunction was found.