On March 17, 1995, a Cessna 185 (registration N714MX) was involved in an aviation accident near Baudette, MN. Investigators recorded the probable cause as: The separation of the left main landing gear due to contact with a crack in the ice, attributed to the operation of a wheeled aircraft on a frozen lake without skis. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot landed on a frozen lake to inspect ice conditions, finding no cracks. While taxiing for takeoff, the left main landing gear collapsed into an unseen fissure in the ice, causing structural separation.
What happened
The pilot reported that he had flown over a frozen lake to determine the condition of the ice and to look for any cracks prior to landing. No cracks were seen and the airplane landed without incident. While taxiing for takeoff, the airplane's left main landing gear dropped into a crack on the ice and the landing gear separated. The airplane's skis were not installed.
The investigation
The examination of the event focused on the interaction between the aircraft's wheeled landing gear and the frozen lake surface. The pilot had conducted a visual inspection of the ice from the air, identifying no visible fractures before executing the landing. However, during the subsequent ground movement for takeoff, the left main landing gear encountered a hidden fissure in the ice. This structural failure was exacerbated by the absence of skis, which would have distributed the aircraft's weight over a larger surface area and prevented the wheels from penetrating the ice sheet.
Findings
The primary contributing factor was the left main landing gear separation caused by contact with an ice crack. The decision to operate a wheeled aircraft on a frozen water surface without appropriate flotation devices (skis) created a high-risk scenario where minor surface imperfections could lead to mechanical failure. The pilot's visual inspection from the air failed to detect subsurface or small-scale fractures that were sufficient to trap the landing gear during ground operations.
Probable cause
The separation of the left main landing gear due to contact with a crack in the ice, attributed to the operation of a wheeled aircraft on a frozen lake without skis.