This occurrence was investigated in 1998, and a summary report was released. The ATSB received new and significant information about this occurrence in 2004 and initiated further investigation. As a result, the ATSB has revised the summary and reissued the report as follows:
The pilot reported that he disembarked from the helicopter, leaving the engine running and the rotors turning, to converse with a stockman. He was returning to the helicopter when he heard the helicopter's engine and main rotor RPM increasing. The pilot attempted to reach the throttle control and was at the right skid before being forced to dive away as the helicopter became airborne. The helicopter flew into the ground about 5 m from its lift off point and was destroyed. There were no injuries. The wind conditions were reported by the pilot as being light and variable.
The pilot reported that he had set the engine throttle to 75%, selected the governor off, and used the cyclic and collective friction to secure the flying controls. The collective was also fitted with a strap to help secure its position but the pilot could not recall if it was deployed. The operator reported that photos taken after the occurrence indicate that the governor was selected on and the collective strap was not deployed. The circumstances of the occurrence are consistent with inadvertent raising of the collective control.