The pilot was contracted to spray three areas of sorghum of 160, 200, and 44 acres on adjacent properties. He was not familiar with the areas. The owner of the 44 acre area had arranged his spraying through his neighbour who owned the larger areas. The owner of the larger areas spoke to the pilot by telephone about his and the 44 acre areas. However, he spoke in detail only about his areas and the directions the pilot should follow to locate them from the air. The pilot was given a comprehensive briefing by radio by the property owner of the larger areas when he arrived overhead before he began spraying. This briefing included detailed information on power lines in the immediate vicinity of the areas. Mention also was made that one of the power lines continued through the property containing the 44 acre crop. The pilot completed spraying of the larger areas and was then told to follow a road to the property containing the 44 acre area. Radio communications between the owner of the 44 acre area and the pilot were difficult because of intermittent transmission problems with the property owner's radio. Nevertheless, the information about which contours were to be sprayed was passed to the pilot. There was no reference to power lines by either the pilot or the property owner during this exchange. The contours to be sprayed curved from a south-easterly through to a westerly direction. A single power line ran approximately east-west along the extreme southern edge of the contour area. Immediately beyond the power line was an area of tall trees. The pilot began spraying north-east/south-west and completed about three quarters of the task with runs in this direction. To spray the final southern-most section of the crop, the pilot changed the direction of his runs to approximately north-south. As the aircraft pulled up at the completion of the second run, it suddenly rotated to a near 90 degree nose-up attitude. The nose then pitched forward and the aircraft entered a steep dive to the ground, coming to rest inverted and bursting into flames. The power line across the southern edge of the crop had been severed. Marks were found on the right main landing gear leg of the aircraft indicating that the wire had contacted the leg some 30 cm above the wheel and then slid down the leg, possibly becoming entangled in the wheel before breaking. The aircraft impacted the ground 123 metres beyond the wire. No fault was found with the aircraft or its systems which might have contributed to the accident. The wire and poles were not hazards for the initial north-east/south-west runs. For the final run, the pilot would have had to pull up early, i.e. before the end of the crop, to avoid the wire. The pull-up appears to have been made in relation to the trees beyond the crop rather than the wire. The single pole which might have warned the pilot of the presence of the power line was of natural colour and against a background of tall trees. It was to the right of the flight path and therefore not in his direct field of view.