Aviation safety investigations & reports

Loss of separation involving Boeing 737 aircraft, VH-YFW and VH-VZD, near Amberley, Queensland, on 11 October 2018

Investigation number:
AO-2018-070
Status: Completed
Investigation completed
Phase: Final report: Dissemination Read more information on this investigation phase

Final Report

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What happened

On 11 October 2018 a Qantas Airways Boeing 737-800, registered VH-VZD (VZD) was inbound to Brisbane, Queensland from Melbourne, Victoria on a scheduled passenger flight. Another Boeing 737-800 also on a scheduled passenger flight, operated by Virgin Australia Airlines and registered VH-YFW (YFW), departed Brisbane, Queensland for Proserpine, Queensland. The two aircraft were on reciprocal tracks in the Amberley Queensland airspace when a loss of separation occurred. The aircraft inbound to Brisbane, VZD, was being controlled on the Royal Australian Air Force (RAAF) Amberley (military) air traffic control (ATC) frequency and the aircraft outbound from Brisbane, YFW, was being controlled on a Brisbane (civil) ATC frequency.

What the ATSB found

RAAF Amberley and Brisbane ATC operated non-linked air traffic management systems, which did not share a common display. Between ATC jurisdictions without linked systems information was shared using manual coordination between ATC elements.

The departing aircraft from Brisbane (YFW) entered Amberley airspace without a hand‑off from Brisbane ATC and without instructions to the crew to change to the Amberley frequency. This resulted in YFW monitoring an incorrect frequency on entry to Amberley airspace and Amberley ATC initially unable to communicate with the flight crew.

The Brisbane departures air traffic controller did not hand‑off the departing aircraft YFW until after it had entered Amberley airspace. In addition, just prior to this incident, Brisbane terminal control unit did not advise Amberley ATC of a change in configuration to the terminal control unit consoles. This led to Amberley ATC contacting the incorrect console position at Brisbane ATC once the departing aircraft had entered Amberley airspace, and delayed the opportunity for Amberley ATC to resolve the impending conflict.

Once appropriate communication with Amberley and Brisbane ATC was established, the outbound aircraft was transferred to the Amberley frequency, and the aircraft were initially diverted away from each other, before being re-established on their respective tracks.

What’s been done as a result

Following the occurrence both RAAF Amberley and Brisbane ATC have taken corrective actions to improve communication and coordination between the two units. This has included deploying a dedicated communications pathway between Amberley approach and the Brisbane Departures South air traffic control positions, and implementing an airspace release that controls the risk that short notice deviations present across the non-linked systems.

Safety message

This incident highlights the importance of clear communication and coordination between air traffic controllers operating in different, yet immediately adjacent airspace. Air traffic controllers need to maintain a clear understanding of responsibility for separation assurance, especially when operating without a shared traffic picture. This incident also illustrates the effectiveness of the conflict resolution training received by air traffic controllers in loss of separation events.

Download final report
[Download  PDF: 166KB]
 
 
Alternate: [Download  DOCX: 409KB]
 

The occurrence

General details
Date: 11 October 2018   Investigation status: Completed  
Time: 1413 EST   Investigation level: Short - click for an explanation of investigation levels  
Location   (show map): near Amberley Airport   Investigation phase: Final report: Dissemination  
State: Queensland   Occurrence type: Loss of separation  
Release date: 04 December 2019   Occurrence category: Incident  
Report status: Final   Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer The Boeing Company  
Aircraft model 737-8FE  
Aircraft registration VH-YFW  
Serial number 41037  
Operator Virgin Australia Airlines  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Nil  
Departure point Brisbane, Queensland  
Destination Proserpine, Queensland  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer The Boeing Company  
Aircraft model 737-838  
Aircraft registration VH-VZD  
Serial number 34198  
Operator Qantas Airways  
Type of operation Air Transport High Capacity  
Sector Jet  
Damage to aircraft Nil  
Departure point Melbourne, Victoria  
Destination Brisbane, Queensland  
Last update 04 December 2019