Accident Sequence
The helicopter was engaged in aerial application of herbicide, operating in eight-minute segments. Between 1430 and 1500 hours, the aircraft was refueled with 29 gallons of 100-octane fuel. At 1600 hours, three minutes after a takeoff, the engine ceased operating while the helicopter was at 50 feet above ground level and traveling approximately 30 mph. The pilot, finding no clear area for a landing, performed an autorotation into trees.
Post-Accident Findings
After the accident, no fuel was found aboard the helicopter. During an initial interview, the pilot stated that the aircraft had run out of fuel. The helicopter has a fuel endurance of about one and one-half hours, and its single fuel tank contains two unusable gallons. Subsequently, the pilot discovered a loose AN fitting on the gas tank sump drain. The pilot noted that the fitting was not leaking when the aircraft was refueled. An area of leaked fuel, estimated at five gallons, was found near the sump drain.