Overview
While on approach to Chevak, the pilot encountered whiteout conditions and limited visibility due to snowfall. The pilot suffered spatial disorientation, and the airplane collided with the ground while executing a traffic pattern circling approach. The accident resulted in the deaths of two passengers and serious injuries to five other occupants.
Accident Sequence
The aircraft was in a traffic pattern circling maneuver when it impacted terrain. The weather environment included whiteout conditions and reduced visibility from snow. The pilot had continued visual flight rules (VFR) flight into these adverse weather conditions, leading to spatial disorientation. The investigation did not specify the aircraft type or registration.
Probable Cause
The official probable cause was determined to be controlled flight into terrain while in traffic pattern circling after the pilot continued VFR flight in adverse weather. Contributing factors were the pilot's spatial disorientation and the whiteout conditions.