On 25 September 2007 at about 0600 Western Standard Time, a Robinson Helicopter Company R22 Beta II helicopter, registered VH-HCN, departed under the visual flight rules (VFR) from Doongan Station in the Kimberley region of Western Australia. The purpose of the flight was to conduct a stock survey in the vicinity of the station. On board the helicopter were the pilot and one passenger.
About 5 to 10 minutes into the flight, the passenger detected a rubber-like burning smell, combined with a smell he associated with hot metal. The passenger informed the pilot who immediately landed the helicopter in a clear area adjacent to a nearby road. The pilot visually inspected the helicopter with the engine and rotor turning, and remarked that one of the rotor system drive belts appeared to be damaged. The pilot decided to return the helicopter to the station, while the passenger elected to remain at the landing site and await recovery by motor vehicle.
The passenger watched the helicopter take off and, owing to the calm conditions, continued to hear the engine noise of the helicopter for some time. The passenger reported hearing variation in the engine noise before it ceased abruptly. In response, the passenger began walking along the road in the direction of the station and discovered the wreckage of the helicopter adjacent to the road. The helicopter had been destroyed by impact forces and fire and the pilot had been fatally injured.
The investigation determined that the helicopter's main rotor system drive belts probably failed or were dislodged, resulting in a loss of drive to the rotor system that necessitated an autorotative landing over inhospitable terrain. The investigation also identified a number of safety factors relating to unsafe decision making, including the operation of the helicopter beyond the allowable weight and centre of gravity limits, as well as evidence of the recent use of cannabis by the pilot.
As a result of this accident, and a number of other similar events that were identified during this investigation, the Australian Transport Safety Bureau has commenced a Safety Issue investigation to determine if there are any design, manufacture, maintenance or operational issues that increase the risk of a failure of the rotor system drive belt in the R22 helicopter.