The pilot had recently been endorsed to fly,"Retractable Undercarriage" and "Constant Speed Propeller" aircraft, and had accumulated six hours on this aircraft type. When the aircraft arrived in the circuit area the wind was westerly at 10-15 knots gusting to 20 knots. The pilot elected to conduct an approach to runway 23, although an into wind runway was available. The reason for this decision was not established. The pilot carried out a go-around from his initial approach. Following the second approach to the same runway the aircraft touched down heavily. Structural damage to the aircraft was sustained, with the left main landing gear door and retraction rod-end bearing being detached from the aircraft. After bouncing on the runway the aircraft became airborne again, and with the landing gear down and hanging free, it was observed to commence another left hand circuit. At an estimated height of 200-300ft, the aircraft turned onto a low level downwind leg with an increasing nose high attitude. The aircraft was then observed to roll into a spiral dive manoeuvre from which it failed to recover. The on-site investigation revealed that the aircraft had impacted soft waterlogged ground, outside the aerodrome boundary, in a near vertical attitude. Rear fuselage distortion was consistent with the aircraft having been rolling about the longitudinal axis at the time of impact. Ground impact had reduced the cockpit area to non-survivable dimensions. The engine and propeller, which were buried in the soft ground beneath the cockpit area, showed no evidence to indicate that the propeller had struck the ground during the heavy landing on the runway. Inspection of the aircraft failed to find any pre-existing defects or abnormalities which were contributory to this accident. Flight test evaluation of the stall characteristics of this model aircraft has indicated that it only marginally achieves the certification requirements, and is difficult to control in all but ideal stall conditions. It is considered probable that the attention of the pilot was diverted from the operation of the aircraft due to the failure of the landing gear to retract and the cockpit workload and associated anxiety following the heavy landing. Medical evidence indicated that both occupants had been holding their respective control columns at the time of impact. What effect this may have had on the development of the accident was not established. The reason why the aircraft entered an abnormal flight manoeuvre at an altitude from which the pilot was unable to recover could not be determined.