Embraer-Empresa Brasileira De Aeronautica EMB-120 ER, VH-XFH

Following investigation of the procedures relating to the use of
"alerted see and avoid" and the provision and issuance of traffic
information by air traffic services the Bureau of Air Safety
Investigation issued interim recommendations (IR) 970175 on 30
January 1998 and IR980005, IR980020 and IR980021 on 25 March 1998
to Airservices Australia. Also, IR970155 was issued on 30 January
1998 to the Civil Aviation Safety Authority.

Subsequently, Airservices Australia responded to IR970175 in a
letter dated 17 March 1998 and to IR980005, IR980020 and IR980021
in a letter dated 27 May 1998. The recommendations and the
respective responses were:

IR970175

The Bureau of Air Safety Investigation recommends that Airservices
Australia in conjunction with the Civil Aviation Safety
Authority:

Review aviation regulations and instructions, with the aim of
maximising the use of "separation assurance" procedures in
conjunction with "alerted see-and-avoid" procedures by pilots of
flights in Class G airspace.

The Airservices Australia letter stated:

"Reference is made to your letter of 30 January 1998 regarding
BASI Interim recommendation IR970175. This Interim Recommendation
more properly falls within the province of CASA to provide further
guidance within the AIP about broadcast arrangements for aircraft
leaving controlled airspace into uncontrolled airspace and should
be addressed by CASA.

"However, inclusion of text similar to that at OPS CTL - 1
paragraph 14.2 "When determining when to make broadcasts on the
Area VHF, the pilot should consider the performance of the aircraft
and the possibility of frequency congestion, if the airspace is
known to be busy "would appear appropriate in the NCTL section to
reinforce the need for timely broadcasts to be made in these
circumstances. Airservices would, therefore support the intent of
the BASI recommendation."

Response classification: CLOSED-ACCEPTED

IR980005

The Bureau of Air Safety Investigation recommends that
Airservices Australia review the guidance in the MATS for the
passing of traffic information by ATS personnel to ensure pilots
have adequate time to assess the potential for conflict with other
aircraft.

The Airservices Australia letter stated:

"Airservices maintains an ongoing process of reviewing the
content of MATS and in line with this recommendation the issue of
flight progress strip presentation will be reviewed. I must point
out that with the advent of the Advanced Australian Air Traffic
System (TAAATS) and associated 'Stripless- environment,
presentation of traffic conflict and alerts will be vastly
different to that which is currently employed. ATS Operational
Policy Branch is developing comprehensive procedures for processing
traffic information under the new environment."

Response classification: OPEN

IR980020

The Bureau of Air Safety Investigation recommends that Airservices
Australia review the MATS in relation to flight progress strip
annotations, to assist ATS personnel to provide more timely traffic
information to flight crew.

The Airservices Australia letter stated:

"Airservices has revised the methodology and parameters for
passing traffic information in its "proposal to amend G Airspace
procedures- originally planned for introduction on 16 July 1998.
This procedure amendment has been deferred until later in 1998 to
facilitate further consultation and development."

Response classification: OPEN

IR980021

The Bureau of Air Safety Investigation recommends that Airservices
Australia review ATS proficiency and continuation training
requirements with a view to personnel undertaking specific traffic
information simulator training on a regular basis.

The Airservices Australia letter stated:

"Airservices has developed its refresher training program for
delivery to operational Air Traffic Services officers to emphasise
elements dealing with the provision of traffic information and
actions to be taken when separation has or may have been
compromised."

Response classification: OPEN

IR970155

The Bureau of Air Safety Investigation recommends that the Civil
Aviation Safety Authority in conjunction with Airservices
Australia:

Review aviation regulations and instructions, with the aim of
maximising the use of "separation assurance" procedures of
maximising the use of "separation assurance" procedures in
conjunction with "alerted see-and-avoid" procedures by pilots of
flights in Class G airspace.

The Bureau of Air Safety Investigation further recommends that
the Civil Aviation Safety Authority:

Implement an education program for pilots to promote the use of
"separation assurance" procedures in Class G airspace.

Local safety action

As a result of the investigation, the companies involved have
revised their procedures in relation to radio communications by
crews when transiting from controlled airspace into non-controlled
airspace.

1. The sector 10 trainee had not received adequate training in the
   control of conflict situations near the base of controlled
   airspace.
2. The sector 10 training officer was not familiar with the
   performance of the trainee and allowed the delay in passing traffic
   information to become significant.
3. The sector 10 trainee did not pass traffic information on the
   Dash 8 to the crew of the Brasilia in a timely manner.
4. The pilot in command of the Brasilia did not establish a
   positive separation procedure with the Dash 8 while on descent from
   controlled airspace.
5. The crew of the Brasilia did not make the required radio
   broadcast on FIS 7 frequency prior to leaving controlled
   airspace.
6. The pilot of the Brasilia decided to proceed visually and use
   "see and avoid" principles.
7. The company procedures of the Brasilia crew did not
   specifically cover the radio procedures for flight from controlled
   airspace into non-controlled airspace.

Air traffic control

The trainee had never communicated traffic information under
these circumstances before and was unsure of exactly how to do so.
The trainee had also not had to pass any traffic information during
the training period on sector 10. This situation may have
contributed to the delayed transmission.

The fact that the training officer and trainee had different
preferred methods of notating flight strips and dealing with
traffic conflictions near the control area boundary, may have
caused some misunderstanding between the trainee and the training
officer which, in turn, may have led to the delay in the training
officer's prompt.

Flight service

Had the trainee controller not volunteered to pass the traffic
information, the decision of the flight service officer to wait for
the Brasilia crew to make their general broadcast on the FIS 7
frequency before passing traffic information on the Dash 8, may
have resulted in the Brasilia passing through the level of the Dash
8 before the crew received the traffic information.

The predication that the crew of the Brasilia would contact him
at "top of descent" did not allow for any of the delays that
occurred. It did not allow for the fact that air traffic control
generally obtain a pilot report of "leaving" a level before
instructing that crew to transfer to the FIS frequency and that a
pilot may wait up to one minute after leaving a level before making
that report to air traffic control.

Crew of the Brasilia

Due to the short notice given to the pilot in command of the
Brasilia about the Dash 8, he had to make a decision on whether to
continue the descent. His choice to continue visually, even though
he had not yet sighted the Dash 8 or made radio contact with the
crew, was made when there was no separation assurance provided by
the manoeuvre. However, the pilot in command of the Brasilia had
sighted the Dash 8, while still in controlled airspace, and elected
to continue descent on a "see and avoid" basis until radio contact
was achieved.

This decision also meant that, due to the frequency congestion,
the required broadcast on the FIS 7 frequency was not made until
the Brasilia was outside controlled airspace.

Documentation

Aeronautical Information Publication

The AIP allows a pilot of an instrument flight rules aircraft to
proceed on a "see and avoid" basis under visual flight rules when
in visual meteorological conditions. These procedures were designed
when the majority of aircraft were comparatively slow and operated
at altitudes below 10,000 ft and may not be appropriate at 20,000
ft with aircraft closing speeds in the region of 500 knots. Whether
this option should be allowed in all circumstances may need to be
reviewed.

Manual of Air Traffic Services

The guidance for air traffic service officers in relation to
traffic assessment in class "G" airspace was not specific in regard
to the timely passing of traffic information and coordination.
Judgement was left to the experience of individual officers and
tended to vary from person to person.

An Embraer E120 (Brasilia) aircraft had departed from Cairns for
Bamaga. The crew were maintaining flight level (FL) 220 in
controlled airspace under the control of Brisbane Sector 10. They
had reported their position as over Lockhart River at 1211 EST with
an estimate for Bamaga of 1236. At about 50NM from Bamaga, the crew
requested clearance to descend.

A de Havilland Dash 8 aircraft had departed Horn Island for
Cairns at 1207 and the crew had reported to flight service (FIS 7)
their intention to climb to FL210. The flight service officer
instructed the crew to contact the Sector 10 controller when
approaching controlled airspace for an airways clearance.

At 1220, the flight service officer passed traffic information
regarding the Brasilia to the crew of the Dash 8.

At 1226, the controller instructed the crew of the Brasilia to
leave the control area on descent and to report passing FL200,
which was the base of controlled airspace in that vicinity. The
crew commenced descent at that time and set up a rate of descent of
2,000 ft/min. Shortly after, the controller advised the crew that
the Dash 8 aircraft was conflicting traffic for their descent and
authorised them to transfer to the FIS 7 frequency.

The pilot in command was the handling pilot of the Brasilia
while the co-pilot was performing the radio tasks. When they
received a clearance to leave controlled airspace they commenced
descent immediately and this action was followed by the receipt of
traffic information regarding the Dash 8. The pilot in command
quickly assessed that this traffic was in direct conflict and
instructed the co-pilot to make a specific call to the crew of the
Dash 8 as soon as he had transferred communications to the flight
service frequency, rather than the general traffic call normally
transmitted.

The co-pilot was waiting to report leaving FL200 as instructed
by the sector controller. As a result of the instruction by the
pilot in command, he made this report early using the phrase
"approaching FL200" and selected the radio to the FIS 7 frequency
as the aircraft was passing FL205.

Further delay was then experienced as the FIS frequency was
congested. The aircraft was passing the base of controlled airspace
and, as the weather was consistent with visual meteorological
conditions (VMC), the pilot in command elected to continue visually
rather than to level off in the control area. He was confident of
seeing the Dash 8 and, in fact, saw the aircraft before the
co-pilot could make his initial radio transmission on the FIS
frequency.

At 1228, the crew of the Dash 8 contacted sector control for an
airways clearance while passing FL188. The controller was unable to
issue a clearance at that time because the altitude of the Brasilia
was unknown and it was not clear if that aircraft had passed the
Dash 8.

At the same time, the co-pilot of the Brasilia was attempting to
contact the Dash 8 crew on the FIS 7 frequency to establish their
respective altitudes. The crews eventually determined that the Dash
8 was climbing through FL190 while the Brasilia was descending
through FL180. The Dash 8 crew had not seen the Brasilia but had
seen a shadow pass over their aircraft. Having established that the
aircraft had passed, the crew of the Dash 8 returned to the sector
control frequency where they were cleared to enter controlled
airspace on climb to FL210.

The point of conflict was outside of radar coverage but
calculation indicated that the aircraft passed with no more than
2,000 ft vertical separation and no discernible horizontal
separation.