Accident Overview
During the arrival phase, the aircraft touched down approximately 1,725 feet beyond the runway threshold. The touchdown was made with the right wing down, and the right main gear was about 37 feet from the right edge of the runway. Following touchdown, the aircraft continued to veer to the right. This movement brought the right propeller into contact with a snowbank that was 2 to 3 feet high. The snowbank was situated between the edge of the runway and the runway edge lights. Upon impact, the number 1 blade separated from the propeller and entered the passenger cabin. This resulted in one passenger being fatally injured and another passenger sustaining serious injuries.
Investigation Findings
The investigation revealed that the snowbank was a product of runway plowing operations conducted two days before the accident. The plowing had left snowbanks at the edge of the runway, inside the runway edge lights. These snowbanks had not been removed in compliance with 14 CFR 139.85 and the airport operations manual. Additionally, no NOTAM was issued to warn of the snowbanks. The company station manager did not communicate the location of the snowbanks to the aircrew.
Lighting System
The flight crew were not aware that when the first officer dimmed the intensity of the approach lights by activating the microphone switch, the runway edge lights also dimmed. The captain reported that he believed he lost some peripheral cues after touchdown.