What happened
During the final stages of landing, approximately 20 feet above the ground, the crew of the aircraft experienced an unexpected transition of a propeller into beta mode. This mechanical event caused the plane to yaw sharply to the right. As a result of this sudden directional change, the pilot was unable to maintain control of the aircraft, leading to a collision with a nearby snowbank. The force of the impact was severe enough to separate the wings from the main fuselage.
Findings
Investigations into the accident focused on several critical areas regarding the mechanical and operational failures. The primary contributing factor was an undetermined malfunction within the propeller system, specifically involving the pitch change mechanism, the reversing system, or the propeller control unit.
Additionally, the following factors were identified during the landing sequence:
- A failure to maintain directional control by the pilot in command.
- An absence of effective remedial actions taken by the crew to counteract the yaw.
- The presence of a snowbank which served as the impact point for the uncontrolled ground loop.