British Aerospace Plc BAe 146-200A , VH-JJX

The aircraft was enroute from Alice Springs to Cairns and was displayed to the Daintree sector controller in the Brisbane air traffic control centre, as a green jurisdiction track and label. Without notice, the display changed to an uncoupled black track without label data, resulting in the sector controller losing situational awareness. Investigation revealed that the Cairns tower coordinator controller had cancelled the aircraft's flight data record (FDR) in the Australian advanced air traffic control system (TAAATS).

The coordinator had assumed that an aircraft on the ground at Cairns was the aircraft displayed as airborne and consequently felt it was unnecessary to check further prior to deleting the record. Local instructions precluded the cancellation of flight data records not under the coordinator's jurisdiction without prior consultation/coordination with other air traffic control units. The possibility of this occurring had been recognised by management and the instructions were issued in an endeavour to prevent inadvertent deletion of a flight data record.

TAAATS displays a warning message requesting confirmation of the requested action when a controller deletes an FDR for an aircraft. This message does not warn controllers that they do not have jurisdiction of the aircraft. Airservices Australia have proposed that the warning message for non-jurisdiction FDRs should be amended to alert controllers to the fact that coordination is required prior to deleting the FDR.

SAFETY ACTION

Local safety action

A request to change the warning message has been submitted by Airservices Australia Northern District (This is one of many TAAATS software modification requests that have been submitted). The modification is unlikely to be actioned in the short term due to the need to action higher priority tasks. Bureau of Air Safety Investigation safety action BASI will monitor Airservices' actions and, in particular, any system modifications which are made to prevent further similar occurrences.