Accident Overview
On August 20, 2017, at 1200 eastern daylight time, a Bell 47G-2A helicopter, registration N9526, was substantially damaged during a hard landing in St Marys, Pennsylvania. The student pilot, who was the sole occupant, was not injured. The helicopter was being operated under Title 14 Code of Federal Regulations Part 91 as a local, solo-instructional flight. Day visual meteorological conditions prevailed, and no flight plan was filed.
Flight History
The flight originated from St Marys Municipal Airport (OYM) at about 1000. The pilot reported performing a preflight inspection and adding 12 gallons of fuel to the tanks, which already contained between 25 and 30 gallons. After departing, the pilot flew for approximately 2 hours before the helicopter "ran out of fuel." The pilot initiated an autorotation to a level, grassy lot, but the helicopter landed hard.
Damage
The helicopter came to rest upright in a grassy lot approximately 2.6 miles west of OYM. The fuselage was structurally damaged, the landing gear skids were spread and forced upward against the fuselage, and the main rotor blades were bent. No fire occurred.
Fuel Examination
An FAA inspector examined the fuel system and found both fuel tanks intact and undamaged, with no fuel leaks. The estimated fuel quantity in each tank was 1 gallon or less, which corresponds to the unusable fuel quantity for each tank.
Pilot Report
The pilot reported no preimpact mechanical malfunctions or anomalies that would have precluded normal operation. He noted that he used an average fuel burn rate for estimating fuel status, without adjusting for pressure, temperature, or other performance metrics.