On December 5, 1991, a Cessna 421 (registration N777RA) operated by Arr Corp. was involved in an aviation accident near Wheeling, IL. Investigators recorded the probable cause as: The pilot's failure to maintain directional control during the landing roll, which was related to ice crystals on the windshield and a slick runway surface. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft veered left during landing roll, striking a snowbank and separating its left main gear after ice crystals obscured the pilot's right-side windshield view.
What happened
During the landing roll, the airplane encountered a slick surface on the runway. The aircraft subsequently veered toward the left side of the pavement. As it moved off the paved surface, the left main landing gear struck a snowbank. This impact caused the airplane to rotate approximately 100 degrees to the left. The aircraft then slid sideways until it came to a complete stop. During this sequence, the left main gear separated from the airframe.
Findings
The pilot reported that ice crystals were present on the right side of the windshield during the landing phase. This obstruction likely contributed to the loss of directional control and the subsequent runway excursion.
Probable cause
The pilot's failure to maintain directional control during the landing roll, which was related to ice crystals on the windshield and a slick runway surface.