A large group of pilots were practicing for the forthcoming World Gliding Championships. There were a number of weak thermals in the area near the starting gate position, and there were several gliders in each thermal. The pilot of VH-FQS encountered a surge of lift and commenced to increase the angle of bank and pull up, achieving a climb rate of about 6 knots. Shortly afterwards, the canopy of this aircraft struck the wing of VH-KYF, which was at a climb rate of about 4 knots. The canopy was shattered, and the left flap of VH-KYF was broken in half. The pilots maintained control of their aircraft, and subsequently landed safely. Neither pilot had seen the other aircraft in the thermal prior to the collision. The competitive nature of the exercise and the large number of aircraft in the area combined to present an operational hazard to those involved.
