Breakdown of separation - Boeing 767-338, VH-OGG and Airbus A320-232, VH-VNC, 74 km north-west of Tamworth Airport, New South Wales, on 1 July 2010

On 1 July 2010, at 1003 Eastern Standard Time, a breakdown of separation occurred between an Airbus Industrie A320-232 aircraft and Boeing Company 767-338 aircraft, about 40 NM (74 km) to the north-west of Tamworth, New South Wales. The aircraft were operating on crossing tracks, with an angular displacement between the tracks of about 50°. Both aircraft were operating at standard cruising levels. The enroute air traffic controller first identified the confliction about 2 minutes before the separation breakdown occurred, when both aircraft were maintaining FL360 and there was 26.2 NM (48.5 km) between their lateral positions. An instruction to climb to FL370 was issued to the flight crew of the 767. When there was 14.6 NM (27.04 km) between the aircraft, the controller subsequently instructed the flight crew of the 767 to expedite their aircraft's climb. Shortly before a 1,000 ft separation standard between the 767 and A320 was established, the radar data indicated that longitudinal separation had reduced, below the required standard of 5NM (9.26 km), to 3.8 (7.04 km) NM.

This incident highlighted the importance of the provision of timely and appropriate traffic information to flight crew by air traffic control, in that it can significantly enhance pilots' situational awareness.  It also supported the opportunity for flight crew to enhance the situational awareness of air traffic control, such as in providing direct information regarding individual aircraft performance.

Airservices Australia (Airservices) has advised that they are conducting a systemic review into the number of breakdown of separation occurrences. Outcomes from that review will be considered in terms of further safety improvement. In addition, Airservices has implemented a Compromised Separation Recovery training module for enroute air traffic control groups.