Cessna 172 N370SP accident near Boulder, Colorado

Probable cause

The pilot's loss of directional control during the landing roll on the slush-covered runway.

NTSB analysis

The pilot departed from a snow-packed runway, flew locally for about 2 hours, and then returned to land. The pilot stated that, while in the traffic pattern preparing to land, the runway still appeared to be snow-packed like it was during the departure. However, the runway was actually slush covered with patches of ice due to the morning sun melting the previously hard snow, and the airplane veered left during the landing roll. The pilot was unable to maintain directional control, and the airplane subsequently impacted a snowbank on the edge of the runway and nosed over, which resulted in substantial damage to both wings and the vertical stabilizer.

Text from the NTSB. Open the NTSB docket for CEN20CA094 for the full record.