What happened
During the landing phase, the aircraft encountered significant snow accumulation on the runway. Immediately after touchdown, the wheels entered a snowdrift approximately 2 feet deep, which caused the aircraft to pull sideways. In an attempt to execute a go-around, the pilot applied full power, but the aircraft subsequently struck another snowdrift measuring between 12 and 16 inches deep. This second impact resulted in the aircraft sliding off the runway.
The accident occurred during civil twilight, specifically 15 minutes after the start of twilight and 44 minutes before official sunrise. The pilot reported that due to the low-light conditions, the snowdrifts were not visible prior to impact.
Prior to the flight, the operator's dispatcher had contacted the airport regarding runway conditions. The airport personnel informed the dispatcher that, to the best of their knowledge, the runway condition was good. However, the individual responsible for runway plowing reported that the snowplow had broken down. This individual had instructed the dispatcher to advise the pilot to perform a visual inspection of the runway before landing. At the time of the incident, there was no NOTAM in effect regarding the runway condition. The Alaska Supplement FLIP cautions that runway conditions are not monitored and recommends a visual inspection prior to use.