While spraying ICI insecticide known as "Karate" the aircraft collided with a powerline and overturned. At the time of impact the pilot was flying a swath run at about one metre above the crop in a southerly direction over a 220 acre paddock. Visibility was good. The pilot had no idea that the wire was there. His first knowledge of it was when the aircraft hit the wire. This wire had not been detected during the initial airborne inspection of the paddock prior to commencement of spraying. Other wires had been detected. The span was about 150 metres. The pilot was splashed in the face with some of the poisonous chemical (S7) but was able to flush his eyes with water very soon after the accident. However his face did suffer burns similar to sunburn. Significant factors The following factors was considered relevant to the development of the accident: 1. The pilot had not detected the powerline during his initial inspection of the paddock prior to spraying.