Incident Overview
A glider pilot was seriously injured when the aircraft collided with terrain during final approach. The accident resulted in substantial damage to the glider.
Flight Sequence
According to the pilot's report, the approach began with a turn from base to final at approximately 400 feet above ground level. The glider was configured with full flaps and spoilers extended. While on final, at about 100 feet altitude, the pilot decided to adjust the flap setting from 20 degrees to 10 degrees due to a crosswind. As the pilot moved the flap handle, it slipped from his hand, causing an instantaneous change to 10 degrees of flaps.
This sudden flap retraction resulted in a loss of lift and a nose-down pitching moment. In response, the pilot pulled back on the controls. This control input caused the glider to stall, and it subsequently collided with the ground.
Pilot Report
The pilot reported that there were no pre-impact mechanical malfunctions or failures of the airframe or engine that would have precluded normal operation. The injuries sustained by the pilot were serious. The glider itself was substantially damaged in the accident.