What happened
The pilot initiated a takeoff attempt from terrain that was completely covered by snow. As the helicopter began to gain altitude, the skids or wheels became caught in the deep snowpack. Instead of lifting clear, the aircraft moved forward while remaining stuck in the drifts.
Recognizing the situation, the pilot reduced collective pitch in an effort to reposition the helicopter and free it from the snow. During this maneuver, a section of the snow beneath the airframe gave way or shifted unexpectedly. This sudden loss of support caused the helicopter to roll over to the right side. The impact with the ground resulted in substantial damage to the aircraft structure.
The investigation
The primary focus of the examination was the sequence of events leading to the rollover. Investigators noted that the snow conditions played a critical role in the initial failure to lift off. The displacement of snow during the pilot's corrective action was identified as the immediate trigger for the roll.
Findings
Several factors contributed to this accident:
- Snow-covered terrain prevented adequate lift and traction during the initial takeoff phase.
- Mired helicopter status limited the pilot's ability to execute a standard climb-out.
- Snow displacement beneath the airframe caused an unexpected shift in support, leading to the rollover.
The accident highlights the hazards of operating rotary-wing aircraft from unprepared, snow-covered surfaces where ground conditions can change rapidly during power application.