What happened
The pilot reported that he was unable to maintain directional control during the landing phase of the flight. The accident occurred under variable wind conditions, which contributed to the loss of control.
As a result of the inability to maintain control, the airplane departed the runway surface and entered into snow. During this excursion, the aircraft nosed over, leading to substantial damage to the airframe.
The investigation
The pilot provided statements regarding the circumstances of the accident. He attributed the incident to his inability to maintain directional control combined with the variable wind conditions present at the time of landing.
No mechanical failure or other contributing factors were identified in the available narrative. The primary cause cited by the pilot remains the loss of directional control during the landing maneuver.