What happened
The aircraft was conducting a landing operation when it veered off the side of the runway. The pilot reported feeling the left main landing gear strike a snow drift, which caused the airplane to swerve violently. As the aircraft moved laterally across the terrain, it crossed through a snowbank on the left side, paralleled the active runway for a short distance, and then re-entered the paved surface before coming to a complete stop approximately halfway down the length of the runway.
The conditions at the airport were challenging due to persistent winter weather. Strong winds prevented snow plow equipment from maintaining a clear path on the runway, as finger drifts formed rapidly after each plowing pass. Significant accumulation had occurred, with two-foot-high snowbanks lining both sides of the runway. The accident took place at night under dark conditions with limited visibility. The ceiling was indefinite at 400 feet with the sky obscured, and visibility was reduced to one and one-quarter miles due to light snow and fog.
The investigation
Examination of the site revealed physical evidence consistent with the pilot's account. The snowbank on the left side of the runway showed distinct wheel marks where the aircraft had crossed through the drift, paralleled the runway edge, and re-entered the paved surface. The structural damage to the airplane was consistent with the landing gear collapsing during the excursion.
Findings
Contributing factors included the inability of snow removal equipment to keep the runway clear due to strong winds and the rapid development of finger drifts. The pilot's perception of hitting a drift triggered the evasive maneuver that led to the gear collapse.