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Factual Information

Summary

FACTUAL INFORMATION

On 17 January 2005, at 0633 Eastern Daylight-saving Time, a Saab Aircraft Company AB SF-340B (Saab) departed Albury Airport on a scheduled passenger service to Sydney, NSW. The aircraft was being operated under the instrument flight rules (IFR). The crew had been authorised by the Albury Tower aerodrome controller to track via Yass on the 043 degree radial from the Albury very high frequency omni-directional radio range (VOR) navigation aid and to climb to flight level (FL) 170. At 0636, a de Havilland Canada DHC-8-102 (Dash 8) aircraft departed Albury Airport on a scheduled passenger service to Sydney, also under the IFR. The crew of the Dash 8 were issued with a clearance by the aerodrome controller to track via the 055 degree radial from the Albury VOR and to climb to FL200.

The Albury aerodrome controller was required to apply non-radar, or procedural, control, in accordance with published procedures, to aircraft operating within the Albury control zone (CTR) and control area (CTA) up to 8,000 ft. Procedural control is achieved by the use of information from sources other than radar. The aerodrome controller later reported that he established a difference of 12 degrees between the tracks of the two aircraft to facilitate the application of a visual separation standard. Visual separation at Albury was achieved by the use of information from sources other than radar. According to the Manual of Air Traffic Services (MATS) 4.5.2.2 (effective 10 Jun 2004):

Aerodrome controllers may also separate by the use of visual observation of aircraft position and projected flight paths.

The airspace above the Albury CTR and CTA was the responsibility of the Hume sector controller (Hume controller) operating in the Melbourne Air Traffic Control Centre. The Hume controller was required to provide a procedural air traffic control (ATC) service to aircraft operating within the Hume sector until that controller could establish a radar separation standard. The minimum horizontal radar separation standard applicable in the Hume sector was 5 NM.

To ensure that a procedural separation standard was maintained between the aircraft in the Hume sector, the Hume controller instructed the Albury aerodrome controller to establish the two aircraft in a step-climb procedure. MATS 4.3.1.8 stated that:

A step climb procedure may be used to simultaneously climb aircraft to vertically separated levels provided that the lower aircraft is progressively assigned levels which provide vertical separation with the higher aircraft.

The Albury aerodrome controller later reported that a step-climb was not practical, because there was insufficient vertical spacing between the two aircraft when he requested altitude reports from the crews. The Albury aerodrome controller did not notify the Hume controller that he was unable to implement the step-climb procedure or that he would provide visual separation until a radar standard was established.

MATS 4.1.1.4 stated that:

Tactical Separation Assurance places greater emphasis on traffic planning and conflict avoidance rather than conflict resolution. This is achieved through:

a. the proactive application of separation standards to avoid rather than resolve conflicts;

b. planning traffic to guarantee rather than achieve separation;

c. executing the plan so as to guarantee separation; and

d. monitoring the situation to ensure that plan and execution are effective.

 
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