Recommendation

SUBJECT



Increased use of available radar coverage to improve safety.





OCCURRENCE SUMMARY



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.





SAFETY DEFICIENCY



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.





ANALYSIS



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.