Flight Details
On 11 September 2000, a Bell 206B helicopter (registration G-LGRM, manufactured 1974) departed Caernarvon for a private pipeline survey in North Wales. The pilot, who held an Airline Transport Pilot's Licence and had accumulated 9,022 flight hours (6,193 on type), was accompanied by one passenger. The forecast weather included a westerly wind of 10 to 15 kt and visibility greater than 10 km, but with reduced visibility in cloud and rain expected in the Snowdonia area.
Accident Sequence
As the helicopter approached Snowdonia, conditions deteriorated to a visibility of 3 to 6 km in rain showers with an overcast cloud base of 1,000 to 1,500 ft in the mountains. The pilot turned the helicopter left toward a steep hillside and descended to maintain visual contact with the ground. During the turn, an unidentified amber caution illuminated on the central warning panel, and an undemanded yaw to the right developed. The pilot suspected a tail rotor failure after corrective pedal inputs failed to arrest the yaw. He then turned in the direction of the yaw in an attempt to regain directional control, but the helicopter continued yawing right and intermittently entered cloud. The helicopter subsequently made contact with the ground and broke up. Both the pilot and passenger, who were wearing lap and diagonal seat belts, survived with minor injuries.
Post-Accident Examination
Examination of the wreckage revealed that the tail rotor drive system was fully functional at the time of impact. The pilot could not determine which amber caution had illuminated.