Air Tractor AT301, VH-AYK, 30 km south of Boggabilla, New South Wales, on 24 April 1990

Circumstances:

The pilot had been airborne for approximately 15 minutes, carrying out aerial spraying of a newly planted crop. The paddock being sprayed was bounded on its northern and western boundaries by a fence approximately 1.2 metres high. Directly above, and running parallel with the western fence, was a three strand power line, the lower cables of which were approximately five metres above ground level. The pilot had flown above the power lines on each previous spray run, crossing the paddock from east to west. After completing a procedure turn the aircraft was lined up for the clean-up run from west to east. The pilot stated that he forgot about the power lines until they became visual again at close range. Knowing he would not be able to climb the aircraft above the cables in the distance remaining, the pilot elected to fly between the lines and the fence. The aircraft struck the two lower cables of the power lines, tearing the fin and rudder from the airframe. The aircraft continued airborne for approximately one kilometre before rolling to the right and striking the ground. It then began to break up as it cartwheeled across the paddock, finally coming to rest inverted. An inspection of the area revealed that the poles that supported the power lines would have been difficult to see, when approaching from the west, as their outline merged with trees in the paddock.

Significant Factors:

The following factors were considered relevant to the development of the accident:

1. The pilot forgot about the presence of the power lines.

2. The pilot did not see the power lines in time to avoid them.

3. The aircraft wire deflector failed on contact with the power lines.