The ATSB has completed its investigation into a near collision between a Jabiru and an A320 near Ballina in November 2020, concluding that the two aircraft weren't aware of each other.
Jabiru J230 24-7456 was tracking from Heck Field QLD to Evans Head NSW when it passed only 600 feet over the top of Jetstar A320 VH-VGP, which was inbound to Ballina Byron Gateway. The near collision took place 12 nm south-west of Ballina.
According to the ATSB investigation released in the past week, the Jabiru pilot was not aware of the A320 and did not have the aircraft's transponder set to transmit altitude.
"The ATSB’s investigation identified that the pilot of 7456 was not aware of the presence of VGP, or that the two aircraft were converging, until having passed above VGP," the ATSB report says. "The flight crew of VGP were also unaware of the presence of 7456 until they were alerted to the impending conflict by the aircraft’s TCAS.
"The ATSB also found the pilot of 7456 did not set the aircraft’s transponder to broadcast altitude data. Consequently, the TCAS on board VGP was unable to provide the flight crew with the necessary information to positively avoid the potential collision."
Neither the pilot of 7456 nor the pilots of VGP recalled hearing broadcasts made on the CTAF. The ATSB noted that the crew of the A320 probably weren't alerted by the Jabiru's call due to the callsign used, and that the J230 pilot probably didn't understand the standard instrument approach phraseology used by the Airbus pilots.
In August 2021, a Surveillance Flight Information Service (SFIS) began operating at Ballina, seven months after the incident. The ATSB also noted that although CASA had done periodic risk assessments of the Ballina airspace, the assessments didn't include transiting aircraft, only those inbound or outbound.
“The airspace surrounding Ballina Airport accommodates a complex mix of aircraft types and operations, and there is a number of other non-controlled airports in close proximity,” said ATSB Chief Commissioner Angus Mitchell.
“The ATSB determined that while the available evidence did not support a conclusion that the present system of aircraft self-separation in Ballina airspace is unsafe, there is the opportunity to potentially further reduce safety risk.”
The ATSB concluded that "measures to further reduce risk might include the increased use of controlled airspace, the increased use of ADS-B aircraft surveillance data, both by air traffic services and in-aircraft, and the identification of any increasing risk through the improved monitoring of the quantity and complexity of aircraft movements in Ballina airspace."
“The ATSB supports systemic enhancements to the overall air traffic system that provide a net overall benefit to safety,” Mitchell.
CASA's Office of Airspace Regulation (OAR) was expected to complete an airspace study into the Ballina-Byron CTAF in February, but the report has not been released.
The full investigation report is on the ATSB website.