Accident Summary
On the afternoon of 8 October 2023, a Cessna 172N, registered VH-RSB, departed from private property near Merriton, South Australia, for a private flight with a pilot and one passenger. At about 1612, while returning to the property and heading west in line with a pre‑prepared runway, the aircraft struck a single‑wire aerial powerline. The collision was followed by terrain impact and an intense fuel‑fed fire. Rescuers removed the pilot and passenger from the wreckage; the passenger was fatally injured, and the pilot later succumbed to injuries they sustained. The aircraft was destroyed.
ATSB Findings
The Australian Transport Safety Bureau (ATSB) found that the pilot likely lost awareness of the powerline and did not see it during the approach to land. The powerline ran obliquely across the approach path near the eastern threshold of the 700‑m runway, which had been positioned in a paddock with one end close to the powerline. This placement increased the risk of a wirestrike. Landing to that end placed the powerline directly in the approach path unless the pilot aimed to land approximately halfway down the runway, which was well within the aircraft’s landing distance capability.
Single‑wire powerlines are difficult to see from the air, and the powerline was not marked in a manner sufficient to enhance its visibility for pilots using the runway (there was no requirement for such marking). While some markers existed on a nearby pole, they were intended to alert pilots flying along the line to the presence of another crossing line, not for approach to the runway. Additionally, the oblique orientation relative to the runway could lead a pilot to misjudge the point of conflict.
The post‑impact fire limited examination of pre‑impact defects, but available evidence indicated the aircraft was heading west in a landing configuration (low engine power, flaps extended) when it hit the powerline. The wind direction, burn pattern, and wreckage position supported a westerly approach. The pilot was familiar with the property and the powerline’s location.
The ATSB also noted possible visual illusions from rising terrain beyond the runway, which could cause a pilot to fly a shallower approach, increasing conflict with the wire. Willy‑willies (dust devils) were common in the area but could not be confirmed as a factor; however, the approach path was not sufficiently distant from the powerline to assure separation even with small deviations.
Runway and Marking Considerations
The 700‑m runway was more than twice the required take‑off and landing distance for a Cessna 172N. Moving the eastern threshold away from the powerline would have reduced risk. Data from the previous month showed the pilot had used the end opposite the wire for five of six landings and take‑offs, suggesting an attempt to mitigate risk. However, unmarked thresholds could lead to inadvertently reverting to the dangerous approach end.
The powerline’s oblique angle relative to the runway further increased the risk of misjudgment. The existing markers near the pole were not optimally placed for runway approaches.
Safety Message
Aerial powerlines are an ongoing threat to flight operations, especially near take‑off and landing. Private runways should be separated from powerlines, even if used by familiar pilots. In several Australian states, pilots can use the Look up and live website or app to plan operations near powerlines. Electrical companies can mark identified hazard lines; property owners may request installation of markers at cost, with some states offering subsidies. The ATSB, in conjunction with the Aerial Application Association of Australia, has published an educational booklet on wirestrikes.