The ATSB is continuing its investigation into a separation occurrence in uncontrolled airspace near Ballina where recorded data showed that the tracks of an Airbus A320 and a private Jabiru two-seat recreational aircraft intersected with a vertical separation of about 600 feet.
The Jetstar Airbus A320, with seven crew and 163 passengers on board, was on approach to land at Ballina Byron Gateway Airport, having operated a scheduled service from Melbourne, while the Jabiru J230D aircraft, with a pilot and a passenger on board, was conducting a private visual flight rules flight from Heck Field in Queensland to Evans Head.
Aircraft operating into Ballina and Evans Head, as well as nearby Lismore and Casino airports, are required to broadcast positional calls on a common traffic advisory frequency, or CTAF, while at Ballina Airport a certified air/ground radio operator (CA/GRO) relays positional information (but does not provide a separation service) to aircraft operating in and out of Ballina to aid pilots with decision making.
The ATSB’s preliminary report into the 28 November 2020 occurrence details that as their aircraft tracked towards Ballina the flight crew of the A320 received a traffic collision avoidance system (TCAS) proximate traffic alert for an unidentified aircraft at an unspecified altitude in the 11 o’clock position, which unbeknown to them, was probably the Jabiru aircraft.
The A320 crew attempted to sight the traffic, but were not successful. The proximate alert then escalated to a traffic advisory.
The flight crew maintained their visual scan and continued with the approach to Ballina.
Subesequent analysis of the A320’s quick access recorder and data recorded by the Jabiru pilot’s OzRunways electronic flight bag app indicated that at approximately 12 NM south west of Ballina Airport, the tracks of the A320 and the Jabiru intersected, with vertical separation between the two aircraft reducing to about 600 feet.
The flight crew of the A320 sighted the Jabiru just prior to passing below the aircraft, the preliminary report notes. The pilot of the Jabiru sighted the A320 shortly after passing above it. Both the pilot of the Jabiru and the A320 flight crew observed no lateral separation between the two aircraft.
“The ATSB’s continuing investigation will include the examination of airspace density levels; airspace suitability; flight crew actions; CA/GRS procedural design and application; and future Ballina airspace plans,” said ATSB Director Transport Safety Stuart Macleod.
Mr Macleod noted today’s preliminary report does not include any safety findings or analysis, which will be detailed in the investigation’s final report
“However, should a critical safety issue be identified during the investigation, the ATSB will immediately notify relevant parties so appropriate and timely safety action can be taken,” he said.