The pilot was conducting sheep spotting operations on behalf of a friend. These operations had been carried out during the previous day, and the pilot had also assisted with mustering after flying for the day had been completed. On the following morning, the pilot commenced further spotting at about 0830 hours, and the aircraft was last seen about one hour later. The wreckage was discovered at about 0945 hours. The aircraft had impacted the ground while in a steep nose-down attitude, probably after stalling at a low height above the ground. No fault or defect was subsequently found with the aircraft or its systems which might have contributed to the accident. Remains of a cake and an apple were found in the wreckage. Medical tests revealed that the pilot had been eating immediately prior to the accident, and had choked when food became caught in his throat. It was probable that this incapacitation resulted in the pilot losing control of the aircraft.