Interim Recommendation IR19970112

Interim Recommendation issued to: Airservices Australia

Recommendation details
Output No: IR19970112
Date issued: 14 July 1997
Safety action status: Closed


Increased use of available radar coverage to improve safety.


A Piper Chieftain (PA-31-350) aircraft was on an IFR flight from Bankstown, via Williamtown and Kempsey, to Coffs Harbour at 9,000 ft. When the PA-31-350 aircraft was approximately halfway between Williamtown and Taree, a Dash 8 aircraft on an IFR flight departed Taree for Sydney. The flight service operator incorrectly assessed that the two aircraft would not be in conflict and did not pass traffic information to either crew. The Dash 8 passed close in front of the PA-31-350.

The aircraft were operating in airspace which was within radar coverage but under the jurisdiction of an air traffic service (ATS) agency using procedural methods of airspace management. Use of the available radar information would have assisted the ATS operator to provide a service with an increased level of safety.


There is radar coverage available, inside and outside controlled airspace, which is not being utilised for the management of the national airspace. An increase in the use of this radar coverage by ATS would improve the level of safety for airspace users and fare paying passengers.


Airservices Australia working group report of the "Tower Radar for Outstations and GAAP" (TROG) investigated aspects of the installation of radar displays and concluded that safety would be enhanced generally by the inclusion of such equipment. As a result of the report Airservices Australia is considering installing radar displays in the towers at Mackay, Rockhampton, Archerfield, Bankstown, Moorabbin, Parafield, Jandakot and Maroochydore.

While radar coverage at low altitudes at locations such as Coffs Harbour, Albury, Wagga and Camden is limited, there is some coverage at higher altitudes that could be utilised to assist in airspace management. For example, Coffs Harbour tower manages airspace from ground level to 10,000 ft using procedural control methods. Additionally, flight service provides a procedural traffic information service to IFR traffic in the area around Coffs Harbour from ground level to 20,000 ft. Yet, there is considerable radar coverage above approximately 6,000 ft which could be utilised to enhance safety for aircraft operating at or above this level.

The TROG report did not address the broader issue of maximising the use of the currently available radar coverage. There are routes within radar coverage which are managed using procedural methods and which are frequently utilised by regional airlines and other IFR traffic. An enhanced level of safety would be provided if radar was used by ATS. Because of the potential safety benefit to be obtained, Airservices should consider increasing the use of radar by ATS at procedural towers and on routes used by RPT aircraft.

Analysis of traffic conflict incidents, which occurred outside controlled airspace, since January 1995 indicated that there were approximately 30 incidents which were within radar coverage and the aircraft involved were being managed via procedural ATS methods. Use of radar in these areas would have assisted the ATS operators in the conduct of their task and may have averted some incidents. During the same period there were 9 incidents, within the airspace controlled by Coffs Harbour tower that were probably within radar coverage. Again, the provision of radar would have assisted the controllers.

Output text

The Bureau of Air Safety Investigation recommends that Airservices Australia review the provision of air traffic services to maximise the use of the currently available radar coverage particularly on routes used by regular public transport aircraft.

Initial response
Date issued: 21 October 1997
Response from: AirServices Australia
Action status: Closed - Accepted
Response text:

Airservices Australia is reviewing the provision of air traffic services with regard to maximising the use of radar services both within and outside controlled airspace.

As you are aware, the Airspace 2000 proposal which Airservices planned to introduce on the 26th February 1998, comprehensively addresses the extension of radar services.

These radar enhanced services include:

Radar Class E airspace from Cairns to Melbourne above 8500 feet. A Radar Information Service (RIS) in Class G airspace within radar coverage.

The Board of the Civil Aviation Safety Authority (CASA) has deferred making a decision on the proposal.

Regardless of the outcome of the Airspace 2000 review by CASA, Airservices intends proceeding with three initiatives to enhance radar services on the 26th of February 1998.

1. Radar Class E airspace will be introduced between 8500 fee and FL125 outside existing Class C airspace from Grafton to Canberra within radar coverage.

2. Brisbane Enroute will provide radar services within the Class C control area steps over Coffs Harbour down to 4500 feet.

3. Sydney Terminal Control Unit will provide radar services to 45nm Sydney in non controlled airspace on a discrete frequency.

These initiatives will increase Airservices use of existing radar coverage for air traffic services. Further expansion of radar services is limited pending decisions on Airspace 2000 by CASA.

Last update 01 April 2011