Collision with terrain involving a Cessna U206E, VH-PLI, 75 km north-north-west of Brunette Downs, Northern Territory

The aircraft took off from the strip near the homestead at about 0645 hours to conduct cattle spotting operations. At about 0930 hours, the pilot reported by radio that he had completed the spotting task and was directed by the property manager to fly to the western section of the property and check the status of three bores. When the manager arrived back at the homestead at about 1200 hours, he found that the aircraft had not returned. Search arrangements were initiated and the wreckage of the aircraft was later found approximately one kilometre from the second in the series of bores to be checked. There were no witnesses to the accident.

On-site investigation revealed that the aircraft had crashed on flat, open terrain while heading in a north-easterly direction. The aircraft initially contacted the ground with the left wingtip followed by the propeller 14 metres beyond this point. There was evidence of a flash fire at this location, and of the aircraft then cartwheeling, before coming to rest 60 metres from the initial impact point. The relationship between the wingtip ground impact mark and the propeller impact point suggested that, at initial impact, the aircraft was in a slightly nose down attitude and banked steeply to the left.

The aircraft was severely damaged by a combination of impact forces and post impact fire. Examination of the wreckage did not disclose any condition or fault which might have contributed to the accident, although fire damage precluded a complete examination of some components, particularly the instruments and controls in the cockpit area.

The weather in the area around the time of the accident was reported to have been fine and hot with a light and variable wind. There were no restrictions to visibility. Flying conditions as described by occupants of the search aircraft were good with only light turbulence.

The broader area over which the aircraft was operating was covered with lush knee-high grass. Advice from the Bureau of Meteorology indicated that the chances of a dust devil (willy-willy) forming in these conditions were very small. Dust devil formation usually required barren, very hot and very dry conditions. No dust devils were observed in the area during the on-site phase of the investigation.

Considerable bird activity was noted around bores on the property. However, no evidence of the aircraft having struck a bird was found, although the post-crash fire could have destroyed any bird remains which might have entered the cabin area.

The notepad apparently used by the pilot to record information on each bore was found along the wreckage trail. Writing in pencil on the notepad indicated that the pilot had inspected the first bore (D-15) and recorded his observations. Beneath this writing was an incomplete recording of information on the second bore (X-8). At the end of this writing was a pencil mark similar to that which might be expected if the writing platform or the pencil was bumped or disturbed.

Bore inspections were a regular aspect of the pilot's flying duties. Inspections involved flying over the bore and checking the amount of water in the holding tank along with the condition of the adjacent animal drinking trough. The task could be readily accomplished from a flying height of 500 feet above ground level.

There was no indication of any physiological or psychological condition which might have affected the pilot's ability to operate the aircraft. He had been flying in the area for some 14 months during which time he had conducted many bore inspection flights. The pilot completed a course in low flying in January 1993.

Factors

The factors which contributed to this accident could not be determined.