What happened
The pilot, holding an airline transport certificate and flight instructor rating, was conducting a landing operation when he encountered adverse weather conditions. During the landing roll, a gust of crosswind struck the aircraft, causing the pilot to lose directional control. The airplane subsequently ground looped, departing from the side of the runway.
After leaving the paved surface, the aircraft descended down an embankment and impacted rocks on the terrain below. This impact resulted in substantial damage to the airframe and components.
The investigation
The investigation focused on the circumstances surrounding the loss of control during the landing roll. The pilot's statement indicated that the primary factor was the sudden gust of crosswind which exceeded his ability to maintain directional control with the available rudder input or braking techniques.