On September 21, 1988, a Cessna 185F (registration N61500) operated by Cape Smythe Air Service was involved in an aviation accident near Chip River, AK. Investigators recorded the probable cause as: The pilot's decision to land on snow-covered tundra that had not yet frozen sufficiently to support the weight of the airplane, resulting in the main landing gear becoming mired in soft soil. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive; 6 related events involving the same aircraft type or operator are linked below.
An air taxi pilot attempted to land on snow-covered tundra near a fish camp, but the ground had not frozen sufficiently to support the aircraft's weight.
What happened
The air taxi pilot was attempting to land on snow-covered tundra near his passenger's fish camp. The tundra had not yet frozen sufficiently to support the weight of the airplane, and the main landing gear quickly became mired in the soft soil, causing the airplane to decelerate rapidly and nose over.
The investigation
The investigation found that the ground conditions were inadequate for the aircraft's weight due to insufficient freezing.
Findings
The primary factor was insufficient ground strength due to the tundra not being frozen.
Probable cause
The pilot's decision to land on snow-covered tundra that had not yet frozen sufficiently to support the weight of the airplane, resulting in the main landing gear becoming mired in soft soil.