CIRCUMSTANCES: "The pilot, accompanied by two employees, was carrying out an aerial inspection of a harvesting operation in a large open paddock. The aircraft had approached from the north, flying at approximately 150 feet above ground level, and carried out a right hand orbit. It then proceeded for a short distance in a southerly direction, before entering a steep descending turn to the left towards a three wire powerline positioned north-south across the paddock, the spans of which were approximately 30 feet above ground level. Approaching the powerline the aircraft was observed to climb rapidly, and a noise like a breaking stick was heard as the left hand wingtip contacted the centre wire of the powerline. The aircraft continued to climb steeply to about 80 feet above ground level. It faltered momentarily before stalling and impacting the ground 100 metres east of the powerline. The aircraft impacted on its left hand wing and nose. It bounced a further 25 metres while turning inverted and became engulfed in a ball of fire which reduced it to ashes. In 1988 the pilot received a serious head injury which resulted in the Civil Aviation Authority not renewing his pilot licence pending additional information from the pilot regarding his medical condition. The pilot did not provide sufficient information but continued to fly up to the time of the accident."