What happened
The captain reported flying a GPS approach to runway 35. After failing to see the runway environment, the crew initiated a missed approach. During this maneuver, visibility improved briefly to approximately 4,000 to 5,000 feet on the approach end of runway 17. The crew elected to circle northwest to prepare for a visual approach to runway 17.
During the landing, the approach was slightly high, causing the flare to be higher than normal. As the aircraft descended, it entered a layer of fog just before touchdown. During the flare, the aircraft drifted to the left, settling onto the runway left of the centerline. Shortly after touchdown, the left main gear struck a snow berm. This impact caused the aircraft to turn sharply to the left and depart the runway.
The investigation
The aircraft sustained significant damage: the nose gear separated from the airframe, the radome was crushed, and the cockpit pressure bulkhead was broken open.
At the time of the accident, the METAR at LGU reported calm winds with visibility of 1/4 statute mile in freezing fog. The sky condition indicated a vertical visibility of 100 feet AGL, with a temperature and dewpoint of minus 7 degrees Celsius.