What happened
The private certificated pilot was operating an airplane equipped with tundra tires during a landing attempt at a remote location. This specific area had been visited by the pilot previously, leading to an assumption about current ground conditions. Upon arrival, the pilot estimated that the landing zone was covered by approximately three inches of powder snow.
During the landing roll, the aircraft encountered significantly different conditions than anticipated. The tires sank deeply into crusty snow that was actually about 14 inches deep. This unexpected resistance caused the airplane to nose over upon touchdown.
The investigation
Post-accident examination revealed substantial structural damage to the airframe. The wings, wing lift struts, and the vertical stabilizer sustained impact damage consistent with the nosing-over event.
Findings
The primary factor contributing to the accident was the pilot's significant misjudgment of the snow depth on the runway surface. The actual depth of fourteen inches far exceeded the pilot's expectation of three inches, leading to loss of directional control and structural failure.