What happened
The pilot was operating an airplane on a return flight to its home base following a prepurchase flight test demonstration. During the approach for landing, the pilot, who was also the potential buyer of the aircraft, attempted to touch down on a runway covered with snow.
Due to the obscured visual cues provided by the snow cover, the pilot misjudged the distance to the end of the runway. The airplane touched down beyond the usable pavement and landed short. Upon impact, the main landing gear wheels sank deeply into the accumulated snow. This sudden loss of support caused the nose of the aircraft to pitch forward violently, resulting in the airplane nosing over.
The investigation
The primary factor identified was the pilot's inability to accurately gauge the runway length due to the weather conditions. The snow cover eliminated standard visual references for depth and distance perception during the final phase of flight.