Introduction
A helicopter experienced a loss of engine power during the last leg of a multi-stop flight, approximately 3 miles from the destination airport. The pilot executed an autorotation but subsequently landed hard, resulting in substantial damage to the tailboom and transmission mounts.
Fuel Management
Prior to departure, the pilot was informed that the helicopter was topped off with fuel, but he did not verify the fuel quantity. During the last leg, he departed with just below 600 pounds of fuel and flew at 120 knots with a tailwind. After the hard landing, the fuel quantity gauge indicated about 225 pounds of fuel remaining. The 20-minute fuel light, which did not illuminate during the flight, came on once the helicopter was on the ground. The pilot was unsure if anyone verified the fuel quantity after landing; however, about 50 gallons of fuel were added, and the helicopter proceeded to the destination airport. The pilot estimated fuel burn at 75 to 80 gallons per hour.
The chief pilot and owner, who refueled the helicopter before the flight, reported that he filled the tank to the bottom of the filler cap on the left side. He estimated this was about 10 to 15 gallons less than the total fuel capacity of 210 gallons. He also estimated fuel burn at about 90 gallons per hour. He stated there were no open mechanical squawks and was not aware of any mechanical issues.
Post-Accident Findings
An FAA inspector examined the helicopter at the accident site. The fuel quantity gauge had been serviced and calibrated earlier in the year but continued to indicate fuel after the helicopter actually ran out of fuel. The 20-minute low fuel light appeared to be functioning normally. The pilot reported no preaccident mechanical failures or malfunctions that would have precluded normal operation.