The aircraft was engaged in spraying a cotton crop. The spray runs were being flown into the west in the late afternoon. About three-quarters of the way into the treatment area a power line crossed the swath path at right angles . The line was carried on poles about 300 metres apart, and the aircraft had crossed under or over the line on about 8 occasions. With the sun shining directly into his eyes, the pilot found it difficult to see the markers. While concentrating on lining up the swath run, he temporarily forgot the presence of the power line. The aircraft collided with the cables and subsequently struck the ground in a steep nose-down attitude 57 metres beyond the run of the lines. The pilot sustained serious burn injuries in the post-impact fire which gutted the aircraft.