The pilot had conducted a soaring flight for an hour in particularly turbulent conditions. The subsequent landing was conducted with a light crosswind from the right. The pilot misjudged the flare, and the aircraft ballooned to a height of about 15 feet, while veering to the left. The pilot then retracted the air brakes and the glider subsequently struck the ground heavily in a slight nosedown attitude. This had been the longest flight undertaken by the pilot, and the weather conditions probably resulted in stress and fatigue. The landing flare had been made with rapid, rather than progressive, control movements. The pilot had then lost directional control, and while he was attempting to regain a normal glide attitude the aircraft had struck the ground in a shallow dive.