During planned stop-work meeting by air traffic controllers, Airservices Australia (Airservices) enacted a contingency plan for the Melbourne Flight Information Region (FIR). That plan amended Class A and C controlled airspace (CTA) to temporary restricted airspace (TRA) and limited the number of aircraft able to fly in the TRA. The plan required pilots of aircraft not approved to fly in the TRA to leave controlled airspace by 1015 CSuT. A Cessna Aircraft Company Citation (Citation) was seen on radar to be operating in the TRA after that time and in potential conflict with a Boeing Company 737 (737). The Adelaide Approach East controller issued traffic information and clearances to enter controlled airspace to the pilots of both aircraft that ensured their separation.
There were no separation standards applicable to aircraft in the TRA. Recorded radar data indicated that the vertical and lateral spacing between the aircraft exceeded the vertical separation standard of 1,000 ft (for aircraft below flight level (FL) 290) and the radar separation standard of 5 NM that would normally apply to aircraft in CTA.
Civil Air, the Australian Air Traffic Control Association notified Airservices of the proposed stop work meeting on 8 March 2002. On 12 March 2002, Airservices issued a notice to airmen (NOTAM) C22/02 regarding the controllers' standdown period between 1030 to 1430 on 13 March 2003. That NOTAM advised that a temporary restricted area and limited route structure would be activated and that specific details would be notified by a subsequent NOTAM. Later that afternoon, Melbourne FIR NOTAM C708/02 was issued advising that pilots of aircraft not in receipt of an approval to operate in the TRA were to be clear of CTA by 1015.
During the morning of 13 March 2002, sometime between 0830 and 0900, the Citation pilot telephoned Airservices requesting approval to fly in the TRA. That request was denied and the pilot subsequently planned to leave CTA, by descending en route, at 1015 in accordance with the NOTAM. The 737 pilot was approved to fly in the TRA.
Prior to the activation of the TRA, the two aircraft were under the control of the Melbourne Centre Canty sector controller. At about 0930, that controller received a temporary local instruction and other documents that detailed how the Canty airspace would be transitioned from CTA to TRA. An FIR Manager was available to assist controllers in the Barossa Group, of which Canty was one sector. At 1020, the Citation pilot requested a clearance to descend to FL200, a level outside the TRA. The Canty sector controller approved the descent but then advised the pilot that he could remain in the TRA. The pilot acknowledged that radio transmission and advised the controller that he would remain in the TRA. The controller was not aware of what aircraft were approved to operate in the TRA.
The plan called for controllers to record details of aircraft that remained in the TRA for subsequent checking by a manager. The intention was to confirm that only aircraft approved to fly in the TRA were actually in the area. At 1025, the controller broadcast that control services were terminated and those pilots should operate in accordance with the TRA NOTAM and closed the Canty sector control position. The controller recorded that both the Citation and the 737 were in the TRA. As Melbourne Centre staff were checking the approval status of the aircraft remaining in the TRA, they were notified by Adelaide Approach controllers that the Citation was in the area without approval.
The contingency plan was developed in 1997 to provide a structured response to, and recovery from, a failure of air traffic services. The plan was reviewed in 1998 - 1999 in preparation for the information technology problems expected during the 2000 new year, and updated in 2001. The plan was broad based and there was limited detail on how it may actually be implemented. When Airservices was notified of the controllers' standdown, it was perceived that a limited segregation service, using the plan, could be offered to assist the aviation industry. The plan was modified in conjunction with the two primary airline operators and the resultant contingency plan complemented their individual company plans.
More detailed local plans, to address the transition to/from the contingency plan, were developed during the period before the notified standdown. Those local plans were not developed in accordance with Airservices safety management processes.
A review of the plan and associated procedures was conducted following the standdown and considerable changes were made before a second similar standdown, involving Sydney and Brisbane controllers, a week later. A further review was conducted after the second standdown and, as a result of both reviews, 139 items were identified for action. A safety assessment of the contingency plan was subsequently conducted in April 2002 resulting in further changes to the plan. Those changes also included limiting the future declaration of a TRA to Class A and C airspace over Australian territory.