Accident Summary
On October 26, 2015, at about 1703 Alaska daylight time, an Airbus AS350B2 helicopter, Canadian registration C-GSLY, collided with terrain during an approach to a remote landing site in the Franklin Bluffs, approximately 29 miles south of Deadhorse, Alaska. The commercial pilot was not injured. The helicopter was registered to and operated by Great Slave Helicopters Limited, Yellowknife, Northwest Territories, Canada, under a North American Free Trade Agreement, 14 Code of Federal Regulations Part 91, Specialty Air Services certificate of authorization. Whiteout meteorological conditions prevailed at the landing site, and a company visual flight rules flight plan was filed. The flight originated from a staging and camp complex located between the James W. Dalton Highway (Alaska Route 11) and the Sagavanirktok River, about 5 miles southwest of the accident site.
Sequence of Events
According to the pilot, he was flying to the landing site to pick up a crew of four seismic workers. Before the accident, he conducted a preflight risk assessment, which noted that the area was conducive to whiteout conditions and that visibility was between 1 and 3 statute miles. The assessment fell within the "low risk go flying" category. While en route to the landing site, the weather began deteriorating, and he encountered an area with flat light conditions over snow-covered ground. The pilot then slowed the helicopter and stayed low to the ground. While slowing down to land, blowing snow from the main rotor downwash reduced visibility to whiteout conditions with no ground reference. The helicopter's right skid contacted the ground, and the helicopter slid right and rolled onto its right side.
Aircraft and Pilot Information
The helicopter, an Airbus AS350B2 (C-GSLY), was not instrument flight rules capable and had no onboard weather capability. The pilot reported no pre-impact mechanical failures or malfunctions with the airframe or engine that would have precluded normal operation. The pilot held a Canadian commercial pilot license and reported having no instrument rating. The helicopter had no radar altimeter or ground proximity warning system installed.
Meteorological Conditions
The pilot reported whiteout meteorological conditions at the landing site. The preflight risk assessment noted visibility between 1 and 3 statute miles and that the area was conducive to whiteout conditions. During the approach, flat light conditions over snow-covered ground were encountered, and the downwash from the main rotor created blowing snow, leading to a complete loss of visual references.
Damage
The helicopter sustained substantial damage to the main rotor system, fuselage, and tail boom as a result of the rollover.