Incident Overview
An aircraft equipped with owner-installed skis experienced a structural failure during landing. As the aircraft touched down, the left ski separated from its mounting, allowing the left ski mount to dig into the snow-covered runway surface. Subsequently, the right wingtip struck a snowbank, and the aircraft came to rest on its nose.
Pilot Account
The pilot reported that the ski mount retaining washer was missing. This omission allowed the ski mount to slide over the retaining nut and cotter pin on the axle end. The pilot stated that the missing washer could have been an oversight during preflight inspection or could have come off during the last flight.
Damage
As a result of the incident, the left ski separated, the left ski mount dug into the runway, the right wingtip struck a snowbank, and the aircraft ended up resting on its nose. No further details on damage were provided.
Probable Cause
The ski mount retaining washer was missing, which allowed the ski mount to slide over the retaining nut and cotter pin on the axle end.