It was reported that the flight had initially been planned as a circuit training exercise. When the wind was reported as a 20 kt crosswind the flight was cancelled. As the aircraft taxied back to the parking area the pilots received a report that the crosswind had dropped to 15 kt. They then decided to takeoff and complete some upper air work. Shortly after the aircraft became airborne, with the pilot-under-instruction at the controls, it encountered a strong wind gust which caused it to roll to the right and descend. The instructor took over control of the aircraft and attempted to correct the situation. Although the aircraft apparently started to respond the instructor assessed that his input was not correcting the situation quickly enough and he closed the throttle, held the control column back and allowed the aircraft to descend to ground level. The aircraft impacted nose first, to the right of the flight strip, before sliding to a stop and overturning. The Bureau of Meteorology reported that the wind was gusting between 12 and 21 kt and changing direction from 340 to 010 degrees at the time of the takeoff. The pilots were using runway 06L.