Accident Overview
A solo cross-country helicopter flight, conducted as part of a helicopter add-on rating, ended in an accident when the engine lost power due to fuel exhaustion. The pilot reported that he believed the fuel onboard would allow for about 1.7 hours of flight time, but after only 1.5 hours, the engine began to run rough and lose power as the flight neared the destination heliport.
Pilot Report
The pilot stated that he lowered the helicopter's collective and entered an autorotation, selecting an unoccupied playground as an emergency landing site. During the descent into the playground area, he raised the collective to avoid a stand of trees, causing the main rotor speed to decay. Subsequently, the helicopter's skids struck the ground hard, and the helicopter rolled onto its right side.
Examination
An FAA inspector examined the helicopter and spoke with the pilot. The inspector noted that the helicopter's fuel tank appeared empty, and the pilot agreed with this observation. The pilot also noted that there were no preaccident mechanical anomalies with the helicopter. The helicopter sustained structural damage to the fuselage, tail boom, and main rotor drive system.
Probable Cause
The pilot's miscalculation of fuel endurance resulted in fuel exhaustion.