Accident Summary
On 4 April 2023, the pilot of a Robinson R44 Raven II helicopter, registered VH-WLH, was conducting aerial mustering operations at Bingegang, Queensland, approximately 60 km south-east of Middlemount. The pilot was the only person on board. While flying to look for straggling cattle, the helicopter struck an aerial powerline and collided with terrain. The pilot was fatally injured and the helicopter was destroyed by a post-impact fuel-fed fire.
Investigation Findings
The Australian Transport Safety Bureau (ATSB) investigated the accident. The pilot had an operational reason to be in the area at low level at the time of the accident. There was no evidence of pre-existing helicopter defects, and the terrain was generally suitable for a landing had an in-flight emergency arisen. The pilot was reportedly familiar with the property and knew that a powerline ran across it, although it was not possible to conclusively determine the level of awareness during the flight. The ATSB concluded that the pilot likely lost awareness of, and did not see, the unmarked aerial powerline during low-level aerial mustering. The powerline was not marked, and there was no requirement to do so. The helicopter model was not able to be fitted with wirestrike protection equipment.
Within the limitations of the available evidence, there were no indications of pre-impact defects, in-flight fire, or birdstrike. Damage to the wire and helicopter was consistent with a wirestrike at a height of about 5.6 m. The wire was partially obscured by large trees and undulating terrain, depriving the pilot of critical visual cues. The task of scanning for cattle was a potential distraction.
Safety Information
This accident provides a reminder of the dangers posed by aerial powerlines during low-level mustering. Helicopter wirestrike protection (WSPS) can provide a last line of defence in the event of a wirestrike. Some aircraft selected for aerial agriculture operations can be configured to include WSPS, but this technology is not currently available on smaller helicopters such as the Robinson R44. The ATSB, in association with the Aerial Application Association of Australia, has released an educational booklet, 'Wirestrikes involving known wires: A manageable aerial agriculture hazard' (AR-2011-028), containing numerous wirestrike accidents and lessons learned. Electrical power and telecommunications companies in Australia can mark powerlines identified as a hazard for low-level flying operations, and some have safety schemes to reduce costs to property owners.