The pilot had planned to operate for 120 minutes before refuelling, and the aircraft had an endurance of 150 minutes. As the aircraft was approaching the refuelling area after a total flight time of 121 minutes, the engine failed. The pilot carried out an autorotative landing, but on touchdown one landing skid became entangled in a large tuft of grass. Believing that the aircraft would roll over, the pilot applied rearward cyclic control. The main rotor severed the tail boom, but the aircraft remained in an upright attitude. Inspection revealed that the engine failed due to fuel exhaustion. Both the fuel gauge and the low fuel warning system were faulty, although the pilot was unaware of this fact. No reason for the apparently higher than normal fuel consumption during the flight could be found.
