Mustering mid-air has familiar ring
The Australian Transport Safety Board (ATSB) has released its final report into the June 2024 fatal mid-air collision between two Robinson R22 Betas engaged in cattle mustering operations.
Vuichard says the most effective method is to begin the flare with a rotor preload of approximately half an inch, then initiate the flare. Image: Claud Vuichard
The report says that between first light and sunrise on the morning of the accident the pilots of four Robinson R22s planned to take-off from the Mount Anderson Station homestead in Western Australia’s Kimberley to transit to a mustering site about a 10-minute flight away.
Shortly after take-off, two of the helicopters collided about 150 ft above ground level. As a result, both helicopters departed controlled flight and collided with terrain.
The ATSB investigation established that the helicopters collided during their initial climb, after the lead helicopter had manoeuvred to the right.
In a finding eerily similar to that of the Gold Coast mid-air between two sightseeing H130s, the investigation found that the two pilots were unaware of the threat until the point of collision.
Chief Commissioner, Angus Mitchell, said: “Neither pilot detected their converging flight paths before the collision. While limited data prevented a full visibility study to establish what each pilot could see, the wreckage examination indicated that at the point of collision the lead helicopter may have been in a blind spot for the second helicopter.”
Vuichard argues that regulators should require OEMs to provide descriptions of autorotations with power recovery. Image: Claude Vuichard
The investigation report considers what actions the helicopters’ operator, Pearl Coast Helicopters, was taking to manage aircraft separation in its operations.
Mitchell said: “The tools used by the operator to consider and manage operational risk were not tailored to their main business of aerial mustering. Further, the risk of collision had not been identified in operational risk assessments, and the operator’s manuals did not provide documented procedures to ensure pilots establish and maintain adequate separation between helicopters.”
Instead, the final report notes, company pilots were permitted to arrange their own separation based on personal preference.
“Pilots routinely flew with reduced vertical and lateral separation, and over time this became an accepted operating preference.”
Angus Mitchell, Chief Commissioner, ATSB
Mitchell said the accident was a demonstration of the need for risk management to identify, assess and mitigate risks.
“Aerial mustering plays a critical role in Australia’s agricultural sector. This tragic accident should serve as a trigger for all mustering operators to consider their risk-management practices and whether they have scaled them adequately for their operation.”
Mitchell added that the accident was another reminder of the fallibility of see-and-avoid as a primary means of identifying and managing the threat of collision.
He said: “Defined separation minimums and pre-planned safe exits which provide an opportunity to identify and respond to emerging collision threats are important tools in assisting pilots avoid mid-air collisions.
“Additionally, airframe obstructions can limit visibility in even the most open cabins. This should be a key consideration when establishing how aircraft should be positioned when flying in close proximity.”
