Accident Details
On November 4, 2008, at approximately 1454 mountain standard time, a Bell 212 helicopter (registration C-GERH, serial number 30768) operated by Sequoia Helicopters Ltd. struck a mountainside while approaching a landing site to drop off skiers near Golden, British Columbia. The main rotor blades contacted the terrain, causing the rotor to separate and strike the fuselage. The helicopter remained upright. The pilot sustained fatal injuries, and the ski guide in the front left seat received serious injuries. The guide and skiers in the rear were uninjured. The uninjured guide shut off the fuel valves and battery switches. There was no fire. Survivors were evacuated by local helicopter operators.
Flight History
The helicopter was transporting skiers for Purcell Helicopter Skiing (PHS). It departed PHS's lodge at 1027 and completed 28 flight legs before the accident. The accident flight originated at Serenity Cabin (approximately 7000 feet asl) with two guides and seven skiers. The intended drop-off at Dawn Mountain was changed to Whitehorn ski run due to a snow squall causing poor visibility. The Whitehorn drop-off site, marked with four flagged poles, was located on a bench at approximately 8100 feet asl, several hundred feet above treeline and about 300 feet below the ridgeline.
Investigation Findings
Post-crash examination revealed no pre-impact defects. The helicopter was carrying three fewer passengers than previous flights and had minimal but sufficient fuel, resulting in a lower gross weight. Density altitude was lower than actual altitude, and a strong uphill wind prevailed. These conditions would have increased the helicopter's performance. The approach to the accident site was flown at a lower altitude and flatter profile than on a previous flight to the same location. The GPS tracking unit stored data from the last nine minutes but did not transmit it; the reason was not determined.
Visibility above treeline was variable due to overcast skies creating flat light and blowing snow. The flags at the drop-off site were visible moments before impact, but it is unknown if the pilot was aware of proximity to the mountainside. The helicopter's forward and vertical speeds were very low at impact, consistent with a normal landing. Wind direction was steady uphill, but gust speeds increased substantially before the accident. A momentary decrease in upflowing air or a reduction in rotor efficiency due to low airspeed (below 20 knots) may have caused a descent into the mountainside, but the exact reason for the rotor strike was undetermined.
Causes and Contributing Factors
The Transportation Safety Board determined that the helicopter's main rotor blades contacted the mountainside during the landing in poor visibility for undetermined reasons. The main rotor separated and struck the fuselage.
Other Findings
Further injury was reduced by the ski guide's shutdown of the helicopter's fuel and electrical systems and by the implementation of Purcell Helicopter Skiing's emergency response plan.