Primary finding
Probable cause
The pilot's failure to maintain clearance from a tree while maneuvering in flight.
Investigator assessment
Analysis narrative
After being towed to altitude, the pilot of the glider began soaring above a mountain peak. After making several circular passes over the peak the glider began to descend, and the pilot initiated a turn to an adjacent ridge. As he passed over the ridge, he felt the glider sink and he initiated a descending right turn. During the turn, the pilot felt the glider "jolt" and yaw to the left. He verified that the flight controls functioned correctly, and initiated an uneventful straight-in approach and landing at the departure airport. Postaccident inspection revealed damage consistent with an in-flight collision with a tree. The glider sustained substantial damage to the left wing spar and aileron during the collision.
Source record
Factual narrative
After being towed to altitude, the pilot of the glider began soaring above a mountain peak. After making several circular passes over the peak the glider began to descend, and the pilot initiated a turn to an adjacent ridge. As he passed over the ridge, he felt the glider sink and he initiated a descending right turn. During the turn, the pilot felt the glider "jolt" and yaw to the left. He verified that the flight controls functioned correctly, and initiated an uneventful straight-in approach and landing at the departure airport. Postaccident inspection revealed damage consistent with an in-flight collision with a tree. The glider sustained substantial damage to the left wing spar and aileron during the collision.