Cessna 172I N35571 accident near Rockford, Illinois

Probable cause

The pilot's inability to maintain directional control during the landing roll after contacting a low-lying snow bank that was obscured by drifting snow.

NTSB analysis

The non-instrument-rated pilot reported that the cloud ceiling and visibility began to deteriorate about 10 minutes after his departure on a 60-nautical-mile cross-country flight. He located the nearest airport, a snow-covered grass runway, and decided to land in lieu of continuing into the deteriorating weather conditions. There was a 65-foot-wide plowed path in the runway that was bordered by snowdrifts. During landing, the airplane struck a low-lying snow bank that was obscured by drifting snow. The airplane then veered left and struck a second snow bank causing substantial damage to the left wing. Prior to departure, the pilot obtained weather information for the planned route of flight using a commercial weather service. The lower cloud ceilings and visibilities were not forecast to begin until after the accident flight was planned to reach the intended destination.

Text from the NTSB. Open the NTSB docket for CEN09CA139 for the full record.