Australia has modified its air traffic control training to improve controllers' conflict resolution skills, according to an Australian Transport Safety Bureau report examining a 3 September 2009 loss of separation incident.
The incident involve a Boeing 737-800 en route from Sydney to Adelaide and an Emirates 777-300 en route from Melbourne to Singapore. The aircraft were on crossing tracks and both were cruising at flight level 300 (30,000ft/9,150m). The controller, relatively new to this sector, failed to notice the conflict developing until the short-term conflict alert system drew his attention to it.
The controller reacted by instructing the 777 to turn to avoid the conflict, but did not use terminology to indicate that the instruction was for traffic avoidance, and the 777 crew failed to respond to two of his calls. So the controller instructed the 737 to turn, and then to climb to FL310, but before vertical separation had been assured, the aircraft had come within 3.6nm (6.6km) of each other, breaching the 5nm horizontal separation rule for instrument flight rules airspace.
The traffic alert and collision avoidance systems on both aircraft were working, but no resolution advisory was triggered in either.
The ATSB says the controller's technique for scanning and assessing traffic for conflicts was not effective, and Air Services Australia has adopted new training for controllers in resolving situations where separation has been compromised.
Source: Flight International
