Breakdown of co-ordination, Gold Coast Airport, Queensland, VH-VQH and VH-VQV

On 3 November 2005, the aerodrome controller (ADC) at Gold Coast Airport, Qld issued the crew of a Boeing 717 (717) aircraft a take-off clearance following closely behind an Airbus A320 (A320) aircraft. The ADC was responsible for the initial visual separation between the two aircraft and also for providing a suitable separation standard for the Brisbane approach controller who was responsible for the overlying airspace. While the ADC was able to continue to visually separate the two aircraft after departure, he was not able to communicate this or arrange another standard, with the approach controller. The two aircraft entered the approach controller's airspace with less than the required radar separation standard and the approach controller took action by initiating a significant change in heading for the 717. There was a breakdown of co-ordination.

The pilot in command of the 717 later reported that the crew had considered the distance behind the A320 to be safe for their departure, and that the crew maintained visual contact with the A320 throughout the takeoff, departure and subsequent tracking.

Documentation available to both controllers provided guidance relating to coordination phraseology and separation responsibilities. The attempted coordination exchange did not adhere to the requirements of these documents and was continuously interrupted as a result of the workload of both controllers. The incident highlighted the need for controllers to use clear unambiguous words and phrases to ensure complete understanding of all communications, including coordination exchanges. It also highlighted the importance of tactical separation assurance which places emphasis on traffic planning and conflict avoidance, rather than conflict resolution.

As both the ADC and the crew of the 717 had continuous visual contact with the two aircraft it was unlikely that the situation would have resulted in the aircraft coming into such close proximity as to have presented any significant safety risk.