According to the glider pilot, the purpose of the flight was to release from the tow about 300 ft above ground level, return to the airport, and land on the departure runway in the opposite direction, which would simulate the response to a "rope-break" emergency during the initial climb. After departure from the runway and release from the tow, the pilot completed a 270° turn on the north side of the runway and had to make another 90°, left base-to-final turn to return toward the runway. While still on the base leg, the glider encountered an 11-knot wind from the south, gusting to 18 knots. The pilot believed that the glider must have encountered "wind shear" as he "lost all elevator control," and the glider then impacted terrain. The Federal Aviation Administration inspector who conducted a postaccident examination of the glider reported that he established flight control continuity. The pilot reported that there were no preaccident mechanical malfunctions or failures with the glider that would have precluded normal operation.