Incident Overview
On a night approach, the aircrew conducted a first ILS approach but did not activate the approach lights. Consequently, they executed a missed approach. For the second approach, the lead-in lights became visible from over one mile away. However, visibility significantly worsened at touchdown.
Approach and Landing
The aircraft landed on the left side of the runway. The left main landing gear encountered snow at the edge of the runway, causing the aircraft to swerve left into a snowbank. The snowbanks were approximately 4 feet high and located about 10 feet outside the runway lights. The pilot reported that no NOTAMs were issued concerning the presence of these snowbanks.
Weather Conditions
The 2221 CST weather observation at St. Louis, taken approximately 15 miles away, indicated visual meteorological conditions (VMC). However, the pilot reported that visibility was variable, ranging between 1/2 and 3 miles.