Incident Overview
A pilot reported to a Federal Aviation Administration inspector an accident that occurred during a cattle herding operation. The pilot had landed the helicopter in a field and exited while the engine was running to speak with the land owner about the flight. While the pilot was on the ground, the collective/throttle increased, causing the helicopter to rock back on its tail. This motion resulted in the separation of the tail rotor. When the helicopter settled back down, the main rotor blades were damaged.
Damage Assessment
The helicopter sustained substantial damage to both the tail rotor and the main rotor blades as a result of the event.
Safety Notice Reference
Robinson Helicopter issued Safety Notice SN-17 in November 1984, revised June 1994, which stated: "NEVER EXIT HELICOPTER WITH ENGINE RUNNING." The notice described that several accidents have occurred when pilots momentarily left their helicopters unattended with the engine running and rotors turning, noting that the collective can creep up, increasing both pitch and throttle, allowing the helicopter to lift off or roll out of control.