Primary finding
Probable cause
The pilot’s improper fuel planning and fuel management, which resulted in a total loss of engine power due to fuel exhaustion and subsequent impact with terrain during an autorotation.
Investigator assessment
Analysis narrative
The pilot departed on an aerial application flight in the helicopter to continue spraying a field with herbicide. The pilot stated that he became preoccupied with touching up areas, which took longer than expected. While flying across the field to begin the next spray pass, the engine experienced a total loss of power, and he immediately knew that it was due to fuel exhaustion. The pilot performed an autorotation and landed hard, which resulted in substantial damage to the main rotor blades and the tailboom. The pilot stated that after the landing, he checked the helicopter fuel tank, and it was empty. There were no mechanical malfunctions or failures of the helicopter that would have precluded normal operation.