The commercial pilot was on a passenger flight when the accident occurred. The pilot said that, due to the cold outside temperature, he departed with the airplane's oil cooler cover in place. He said that the engine temperature increased and that he decided to land and remove the oil cooler cover. He then landed on a snow-covered lake and after landing he continued laying down tracks in the snow to aid in his departure. While laying down tracks the airplane's skis hit a ridge hidden under the snow. The pilot then examined the airplane and found that a fuselage frame tube had broken near the right main landing gear attachment. The pilot said that there were no mechanical problems with the airplane prior to the accident.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:

The pilot's selection of unsuitable terrain for landing, which resulted in structural damage to the airplane during landing.