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Envoy 606 (Falcon 900) was arriving at Canberra from Sydney and was assigned 7,000 ft on descent on the Wollongong - Canberra track. The pilot had been given a requirement to reach 7,000 ft by 20 DME Canberra due to conflicting traffic and reported at 7,000 ft when 25 NM from Canberra. VH-IEL (Cessna 172) had departed Goulburn for Canberra on a VFR training flight with the student performing all the functions and the instructor engaged in an examining role. The aircraft was outside controlled airspace at 6,500 ft and was tracking via Lake Bathurst. The control area (CTA) step passes through the north eastern corner of Lake Bathurst and is 30 NM from Canberra. However, the reporting point is an island in the centre of the lake and this is 28 NM from Canberra. The student was approaching Lake Bathurst and prepared to contact Canberra Approach to request an airways clearance but for some reason delayed the call until at the CTA boundary. The instructor was allowing the student to conduct his own operation as a test was in progress and although mindful of the requirement to remain outside controlled airspace until obtaining a clearance, he elected to let the situation continue up to the last instant. The instructor was about to instruct the student to make an orbit when the student made contact with air traffic control (ATC). At the time of the call by VH-IEL, ATC observed the aircraft to be 28 NM and Envoy 606 25 NM and therefore considered that a breakdown in separation had occurred. By the time altitudes were checked and VH-IEL positively identified, the aircraft were 5 NM apart and a radar separation standard existed. The tracking tolerances were 4 NM for VFR flight and 1.2 NM for the radar at that distance. The required separation standard was 5 NM by radar or 1,000 ft vertically. To remain in controlled airspace the pilot of Envoy 606 would need to be 9,000 ft at 30 NM. The descent profile of Envoy 606 was steeper than normal due to the requirement to reach 7,000 ft by 20 NM. Significant Factors 1.The student pilot allowed his aircraft to proceed to the CTA boundary before initiating an airways clearance request to ATC. 2.The instructor on VH-IEL allowed his aircraft to penetrate CTA prior to obtaining an airways clearance.
General details
Date: 19 August 1993 Investigation status: Completed 
Time: 11:44 EST  
 Investigation type: Occurrence Investigation 
 Occurrence type: Loss of separation 
Release date: 17 January 1994 Occurrence class: Airspace 
Report status: Final Occurrence category: Incident 
Aircraft 1 details
Aircraft manufacturer: Cessna Aircraft Company 
Aircraft model: 172M 
Aircraft registration: VH-IEL 
Sector: Piston 
Damage to aircraft: Nil 
Departure point:Goulburn NSW
Destination:Canberra ACT
Aircraft 2 details
Aircraft manufacturer: Dassault Aviation 
Aircraft model: Mystere-Falcon 900 
Aircraft registration: UNKNOWN 
Sector: Other 
Damage to aircraft: Nil 
Departure point:Sydney NSW
Destination:Canberra ACT
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Last update 23 July 2015