The ATSB has provided a substantive update on its on-going investigation into a midair collision near The Oaks, south-west of Sydney, on 26 October last year, with the release of an interim report.
The 35-page report outlines in detail evidence gathered during the investigation as well as contextual information around the circumstances of the accident. It does not contain findings, which will be made in the ATSB's final report, to be released at the conclusion of the investigation.
The two aircraft, a Cessna 182, which had departed Camden and a Jabiru recreational aircraft, which was returning to land at The Oaks, collided in-flight about 2.7 km west of The Oaks aerodrome. Both aircraft impacted heavily-wooded terrain and all three occupants were fatally injured.
"As we previously detailed in a preliminary report, the Jabiru was one of two aircraft that had departed The Oaks for a planned flight to Cessnock, but both decided to return to The Oaks after encountering turbulence en route," ATSB Chief Commissioner Angus Mitchell outlined.
The Cessna, meanwhile, had been conducting circuits at Camden, as part of a commercial pilot licence flight test, having originally departed Shellharbour.
"The collision occurred when the Jabiru was flying to the north on the downwind leg of the circuit for The Oaks ahead of a planned landing, and as the Cessna was tracking to the southwest."
Both aircraft were on near reciprocal headings and on relatively constant flight path trajectories at the time of the collision, with video from an onboard camera on the Jabiru showing it in straight and level flight and the Cessna climbing.
The collision occurred at an altitude of approximately 2,200 ft, about 1,300 ft above the runway at The Oaks.
"The video camera in the Jabiru has been instrumental in establishing the accident's sequence of events and in allowing us to undertake extensive analysis of radio calls made prior to the collision," Mr Mitchell said.
The Oaks aerodrome is in non-controlled airspace, meaning pilots are responsible for maintaining separation from other aircraft using 'alerted see-and-avoid' principles - making required and recommended position and intention radio calls on a common traffic advisory frequency (CTAF) and maintaining a visual scan.
Camden Airport, meanwhile, about 6.5 NM (12 km) to the north-west, is in controlled airspace which extends over a 2 NM (3.7 km) radius, with separation provided by an air traffic control tower.
"While radio calls made on The Oaks CTAF are not recorded, the video showed transmissions being both made and received by the Jabiru on The Oaks CTAF radio frequency," Mr Mitchell said.
The duration and timing of all radio calls received by the Jabiru in the six minutes prior to the collision were consistent with those calls being made by the two other aircraft in the group - a Sonex on the ground, and a second Jabiru which also returned to The Oaks.
Noting that The Oaks CTAF was not recorded, the last recorded radio call made by the Cessna was reading back a clearance to Camden air traffic control for a touch-and-go and an upwind departure from Camden.
The report also details that the Cessna and the second Jabiru aircraft passed each other while the second Jabiru was about to turn onto the final leg of the circuit to land at The Oaks. Analysis of flight data showed that this Jabiru passed in front of and about 400 ft above the Cessna on a near reciprocal heading.
The report notes that CASA guidance states that pilots should avoid flying over non-controlled aerodromes at an altitude that could result in a conflict with aircraft operations there, while a warning label on the relevant aeronautical chart (the Sydney VTC) recommends overflying The Oaks not below 2,500 ft.
"This investigation has benefited from a wide range of data sources such as the video, ASD-B and transponder data, and from electronic flight bag apps to build a picture of the flight paths of both accident aircraft and radio transmissions," Mr Mitchell noted.
"From here the investigation is looking at wider considerations, such as CPL flight test procedures and practices, and reviewing radio communications, electronic conspicuity and surveillance equipment for aircraft in non-controlled airspace."
The investigation's final report is anticipated to be released in 2026.
"We look forward to concluding our analysis of the circumstances of this tragic accident and sharing our findings to help prevent similar accidents in the future," Mr Mitchell concluded.
You can find here the interim report: Midair collision involving Jabiru UL 450, 19-4079, and Cessna 182, VH-APN, 2.7 km west of The Oaks, New South Wales, on 26 October 2024
