The pilot stated that just after the aircraft became airborne it encountered a strong gust of wind. The left wing tip and nosewheel struck the ground and the aircraft overturned. During the take-off run the pilot held back pressure on the control column and at 50 knots selected 10 degrees of flap, the aircraft becoming airborne after a ground roll of only 170 metres. The take-off distance required was 650 metres, however, the take-off was attempted on an unprepared salt pan with an available take-off distance of 300 metres. The pilot had operated from this area previously but on this occasion the aircraft was at a higher all up weight. The wind gust reported by the pilot was probably associated with a willy willy, encountered when the aircraft was at a low airspeed.