The ATSB has released a preliminary report from its continuing investigation into a mid-air collision involving two Robinson R22 helicopters at Mount Anderson Station in Western Australia's Kimberley region.
The report details that on the morning of 25 July 2024, 4 R22 helicopters were being prepared to take part in mustering along a section of the Fitzroy River, about a 10-minute flight from the station homestead.
The 2 accident helicopters had been parked in a grassed clearing near the homestead, while the other 2 R22s were parked about 400 m to the west.
Shortly after 0600 the 2 accident helicopters took off from the clearing and began flying to the west towards the other 2 helicopters, which were then to follow them to the muster site.
As they approached the second pair of helicopters, the airborne R22s collided. With their pilots unable to maintain control, the helicopters collided with terrain. Both pilots were fatally injured.
"The pilots of the third and fourth helicopters observed the accident helicopters flying towards them at a height of about 100 ft, with one helicopter flying behind, and below, the other," said ATSB Director Transport Safety Dr Stuart Godley.
"Wreckage examination found damage to the right side of one helicopter which was consistent with a rotor blade strike from the other, while there was no evidence of an in-flight break-up, or any loss of flight control continuity prior to the collision."
To date, the ATSB investigation has included examining the accident site and wreckage, collecting meteorological data and operator, pilot and aircraft-related records, and conducting interviews with involved parties.
"As the investigation continues, it will include further examination and analysis of weather conditions, helicopter components, witness information, recorded audio, electronic items retrieved from the accident site, pilot qualifications, operational documentation," Dr Godley said.
Following the accident, the operator conducted a review of the operations manual and revised procedures for operations involving multiple aircraft and the operation in the vicinity of other aircraft, the preliminary report details.
The ATSB will release a final report, which contain findings and analysis, at the conclusion of the investigation.
"However, should we identify a critical safety issue during the course of the investigation, the ATSB will immediately notify relevant parties so safety action can be taken," Dr Godley noted.
You can find here the preliminary report: Mid-air collision involving Robinson R22 Beta II, VH-HQH and Robinson R22 Beta II, VH-HYQ, 51 km south-south-east of Curtin Airport, Western Australia, on 25 July 2024
