Before he commenced spraying operations in the particular paddock, the pilot had been reminded of the presence of power lines in the area. There was also a group of trees in the paddock, and the pilot sprayed the clear area first, passing over the power lines on at least two occasions. He then advised the property owner by radio that he would spray in the vicinity of the trees "freehand", before resuming normal spraying runs. On the first pass near the trees, the aircraft struck the power lines. The cockpit to fin cable deflector failed and one power line struck the fin about 50 centimetres from the top. The resulting loads caused the rear fuselage to fail, and the entire empennage separated from the aircraft, which dived to the ground and came to rest inverted. The pilot was able to recall that he had the power lines in sight as he lowered the nose to pass under them. It was likely that he misjudged the height of the tail of the aircraft relative to the cockpit with the aircraft in a descending attitude. The injuries suffered by the pilot were made more severe by virtue of the fact that he was not wearing a helmet, and because the seat belt buckle had failed. It was determined that the seat belts fitted to the aircraft were not of a type approved for agricultural operations, but it was not established when or why these particular belts had been installed.
