What happened
Prior to departing a golf course in Berlin, Massachusetts, for an airport in Fitchburg, Massachusetts, the pilot refueled the helicopter with two to two-and-a-half gallons of unleaded automobile fuel because the aircraft was low on fuel. While starting a flare for landing at Fitchburg, the engine flamed out and the helicopter landed hard. The main rotor blade severed the tailboom.
The investigation
Examination revealed that there was no usable fuel remaining on board. Indications are that the pilot had been flying with the caution breaker pulled because the engine chip lights were on. The pulled breaker would also prevent the low fuel light from coming on.
Findings
The probable cause of this incident was the pilot's decision to use automotive fuel in a turbine engine, which led to fuel exhaustion. Contributing factors included the pilot's failure to monitor fuel quantity due to a pulled circuit breaker, which disabled the low fuel warning light.