What happened
The pilot in command was preparing the airplane for departure by taxiing on a snow-covered surface. While maneuvering toward the runway threshold, the pilot did not observe double tracks left by a snow machine ahead. As the aircraft crossed these depressions, the nose of the plane bounced upward due to the impact with the uneven terrain.
Reacting to the bounce, the pilot attempted to lower the nose back down. However, the nose wheel ski tip sank deeply into the soft snow beneath the tracks. The excessive downward force and resistance from the snow caused the structural integrity of the landing gear to fail, resulting in a collapse of the nose gear assembly.
The investigation
Examination of the accident site revealed clear evidence of the double snow machine tracks that had been missed by the pilot during the taxi phase. The soft consistency of the snow at the location of the tracks contributed to the nose wheel ski tip digging in rather than rolling over the obstacle. No mechanical pre-existing failures were noted in the narrative; the collapse was a direct result of the ground contact dynamics.
Findings
The primary factor leading to the accident was the pilot's failure to see and avoid the double snow machine tracks while taxiing. The subsequent bounce and aggressive nose-down input caused the nose wheel ski tip to penetrate the soft snow, leading to the collapse of the nose gear. This incident highlights the hazards of taxiing on unprepared snowy surfaces where hidden obstacles or ruts may not be immediately visible.