Aviation safety investigations & reports

Breakdown of separation - Boeing B737, VH-VBK and Israel Aircraft Industries Westwind 1124, VH-AJG, 22 km South of Williamtown (Newcastle Airport), NSW, 1 February 2011

Investigation number:
AO-2011-011
Status: Completed
Investigation completed

Summary

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At 1305 Eastern Daylight-saving Time on 1 February 2011, a breakdown of separation occurred 22 km south of Williamtown (Newcastle Airport), New South Wales between a Boeing B737-7Q8 (737), registered VH-VBK, and an Israel Aircraft Industries Ltd Westwind 1124 (WW24) aircraft, registered VH-AJG. Both aircraft were in communication with and under the jurisdiction of Department of Defence (DoD) air traffic controllers based at Williamtown.

Separation between the aircraft reduced to 0.7 NM (1.3 km) on radar and 400 ft vertically when the required separation standard was 3 NM (5.6 km) or 1,000 ft. The vertical separation achieved was as a result of the 737 flight crew responding in accordance with a resolution advisory provided by their aircraft's traffic alert and collision avoidance system.

The investigation identified a series of errors by the Williamtown Approach controllers involving separation assurance, coordination and communication, and compromised separation recovery.

The investigation also identified three safety issues. The DoD advised that they reviewed and amended Williamtown procedures, introduced compromised separation recovery techniques training and trialled use of the conflict alerting function in the Australian Defence Air Traffic System at Williamtown.

Download Final report
[Download  PDF: 635KB]
 
 
Alternate: [Download  DOC: 704KB]
 

Safety Issues

Go to AO-2011-011-SI-01 - Go to AO-2011-011-SI-02 - Go to AO-2011-011-SI-03 -

Compromised separation recovery training

The Department of Defence’s air traffic controllers had not received training in compromised separation recovery techniques.

Safety issue details
Issue number: AO-2011-011-SI-01
Who it affects: All Department of Defence air traffic controllers
Status: Adequately addressed

Disabling of Australian Defence Air Traffic System conflict alerts

An important alerting function within the Australian Defence Air Traffic System had been disabled at Williamtown to prevent nuisance alerts.

Safety issue details
Issue number: AO-2011-011-SI-02
Who it affects: All RAAF Base Williamtown based Department of Defence air traffic controllers
Status: Adequately addressed

Air traffic control procedures at Williamtown

The Williamtown air traffic control procedures did not clearly define the separation responsibilities and coordination requirements between the Approach sectors for departing aircraft.

Safety issue details
Issue number: AO-2011-011-SI-03
Who it affects: All RAAF Base Williamtown based Department of Defence air traffic controllers
Status: Adequately addressed
General details
Date: 01 February 2011   Investigation status: Completed  
Time: 1305 ESuT   Investigation level: Complex - click for an explanation of investigation levels  
Location   (show map): Williamtown Airport, South 22 km    
State: New South Wales   Occurrence type: Loss of separation  
Release date: 07 March 2012   Occurrence class: Airspace  
Report status: Final   Occurrence category: Serious Incident  
  Highest injury level: None  

Aircraft 1 details

Aircraft 1 details
Aircraft manufacturer The Boeing Company  
Aircraft model 737  
Aircraft registration VH-VBK  
Serial number 30648  
Type of operation Air Transport High Capacity  
Damage to aircraft Nil  
Departure point Williamtown, NSW  
Destination Melbourne, Vic  

Aircraft 2 details

Aircraft 2 details
Aircraft manufacturer Israel Aircraft Industries Ltd  
Aircraft model 1124  
Aircraft registration VH-AJG  
Serial number 281  
Type of operation Charter  
Damage to aircraft Nil  
Departure point Nowra, NSW  
Destination Williamtown, NSW  
Last update 14 November 2018