On 3 September 2009 at about 1859 Eastern Standard Time, a Boeing 737-838 aircraft was en route from Sydney, New South Wales to Adelaide, South Australia and a Boeing 777-31H aircraft was en route from Melbourne, Victoria to Singapore. The aircraft were on crossing tracks and both were cruising at flight level 300. The air traffic control separation standard was infringed and there was a breakdown of separation.
The air traffic controller responsible for separation of the aircraft had recently completed the air navigation service provider's approved training, but had not recognised the potential conflict between the two aircraft.
As a result of this incident, Airservices Australia has amended the compromised separation recovery component of an air traffic controller's training, and introduced a compromised separation recovery element into its final controller field training.
