Update: 22 June 2012

On 30 March 2012, at 2140 and 2155 Eastern Standard Time respectively, the two rostered night shift air traffic controllers for the Kimberley/Cable (KIY/CBL) airspace sectors advised that they were unable to attend for their duties, which were from 2315 to 0600 the following morning. A controller who was already working the evening shift extended their duty for an additional period and another controller agreed to commence their pending morning shift earlier than rostered. No other controllers were available to cover the remaining duty period.

In response to this controller unavailability, the air traffic control (ATC) provider requested the Civil Aviation Safety Authority Office of Airspace Regulation to designate the affected airspace as a Temporary Restricted Area (TRA) with Temporary Information Broadcast Area procedures to apply from 0015 to 0515 on 31 March 2012. The provider allocated a Contingency Response Manager to oversee the implementation of the procedures during the TRA period.

Due to a number of factors that are yet to be fully examined, two aircraft entered the TRA without the Contingency Response Manager being aware of their presence. The first aircraft, an Airbus A330 (A330) on a flight from Denpasar, Indonesia to Melbourne, Australia, was detected at 0500 when the flight crew contacted a Melbourne Centre controller because their aircraft was at the Brisbane/Melbourne Flight Information Region (FIR) boundary. The second aircraft, an A330 on a flight from Denpasar to Sydney, Australia, was detected at 0640 when the flight crew contacted Melbourne Centre because their aircraft was at the FIR boundary.

Because the second aircraft had operated in controlled airspace without the knowledge of the relevant controller from 0515 (when the controlled airspace was reactivated) to 0640, there was a loss of separation assurance. However, no other aircraft were in close proximity to the second A330 during that time, and there was no breakdown of separation.

The investigation is continuing and will include:

• analysis of the ATC data associated with the two flights
• review of the ATC provider's contingency procedures  
• review of the role of the Contingency Response Manager and the training and guidance provided to personnel who act in this role
• review of the systems used to provide information about flights between different jurisdictions.