The aircraft was being winch launched on the pilot's second solo flight. Experienced observers on the ground reported that the takeoff appeared normal, but soon after liftoff the aircraft adopted a steeper than normal nose up attitude. The pilot appeared to correct this to some degree but the aircraft continued to climb slightly steeper than normal. A video tape recording of the flight showed that, at a height of between four and five hundred feet above ground level, the tow cable broke. The nose attitude of the aircraft was quickly lowered to what appeared to be a near level flight attitude. A short time later, however, the glider rolled to the left and the nose dropped. The aircraft then spiralled through one and a half turns before impacting the ground. It would appear that, following the cable break, the pilot did not lower the nose sufficiently to maintain flying speed. As a result, the aircraft stalled and then entered a spin. The pilot had not experienced a tow cable break prior to this accident but had been instructed on the procedure to be adopted in the event of such an occurrence. The cable failure would probably have taken the pilot by surprise and this, coupled with his low experience level, could have contributed to the loss of control of the aircraft. These aspects could also have affected the pilot's ability to regain control of the aircraft.