The student pilot was carrying out a series of "touch and go" circuits using gravel runway, 06. The wind was reported as being easterly at about 5 knots. On the fourth "touch and go", after a normal landing, the student applied full power, selected the carburettor heat control to cold and commenced to raise the electrically actuated flaps. He said he looked up and saw that the aircraft had commenced to veer to the left. The student closed the throttle and attempted to correct the swing with opposite rudder but was unable to prevent the aircraft striking a 30 centimetre high earthen bank bordering the edge of the runway. The nose gear was torn from its mounting and the aircraft overturned, coming to rest just beyond the runway edge. The earth bank was formed during recent grading of the strip. This work was interrupted by wet weather and was incomplete at the time of the accident.