A farmer requested that a pre-notified weed spraying operation be carried out urgently. The pilot briefed the
markers on the swathe width only and gave them a sketch map of the area to be sprayed. When airborne, the
pilot found that the markers had taken up position in the wrong paddock. The aircraft was landed back at Farm
Hill and instructions given to re-direct the markers. Arriving back at the spraying site the pilot saw one
marker in position and commenced his spray run over him. At the other end of the field the farmer, who was
an experienced marker, left his utility truck at the end of the paddock and stood in front of it to mark for the
runs. As the aircraft, flying with its wheels about 18 inches above the ground approached, the farmer moved
rapidly to the right of the flight path. The aircraft continued straight ahead and as it commenced to climb at
the end of the run its starboard wheel struck the door of the vehicle. The wheel rim, tyre and tube were dislodged
and later, while landing at Kununurra aerodrome, the starboard undercarriage collapsed and further
damage occurred.