What happened
The accident occurred during the landing roll phase of flight. The aircraft was operating on a snow-covered landing strip that measured approximately 1,200 feet in length and 12 feet in width. As the airplane touched down and began its rollout, the skis encountered a rut left by a snow machine.
The presence of this rut caused the skis to track laterally, pulling the airplane toward the left side of the runway. In an attempt to regain control and maintain the centerline, the pilot applied power and full right rudder input. Despite these corrective actions, the aircraft continued its leftward deviation. The airplane eventually departed the paved or prepared surface and struck trees located on the edge of the landing strip.
The investigation
The investigation focused on the physical evidence at the site and the operational conditions. The primary factor identified was the interaction between the aircraft's skis and the uneven snow surface. The specific rut created by ground maintenance equipment provided a lateral force that overwhelmed the pilot's ability to maintain directional control, even with maximum rudder authority and power application.
Findings
The sequence of events indicates that the landing strip conditions were critical to the outcome. The combination of a narrow, short runway and the presence of deep snow machine ruts created a hazardous environment for ski-equipped operations. The pilot's timely application of power and full right rudder demonstrates appropriate reaction to the loss of directional control, but the physical constraints of the terrain made recovery impossible.
Safety message
Operations on snow-covered strips require careful attention to surface conditions. Ruts from grooming or maintenance equipment can significantly affect directional control for ski-equipped aircraft. Pilots should assess the landing strip thoroughly before touchdown and be prepared for reduced effectiveness of rudder inputs in deep or uneven snow.