This document provides CASA's responses to the safety concerns
raised by the Bureau of Air Safety Investigation (BASI), Air Safety
Interim Recommendation No IR 980253. The format used is to print
each of BASI's concerns in bold type followed by CASA's
response.
a)"The Independent review process for the introduction of
airspace changes was removed when CASA, as the regulator and safety
auditor of the airspace system, also actively assumed the primary
role for the design, safety analysis, promotion and management of
the Airspace 2000 program from Airservices Australia in late
1997.
Previously Airservices Australia conducted these airspace change
activities and CASA had a clearly defined process for monitoring
and evaluating this process. However, when CASA assumed the role
formerly exercised by Airservices Australia, no system was put in
place to ensure that CASA's own work was similarly evaluated for
the Class G Airspace Demonstration. No such system is yet in
place".
CASA Response:
In view of the fact that a review is being conducted in
accordance with a Ministerial Direction, it is considered
inappropriate to respond to the above concern at this time.
b)"The CASA safety case process did not provide an integrated
summary of all hazards considered, and their associated risk
levels, mitigators, and anticipated effectiveness of the
mitigators. In addition, the CASA safety case process did not
include a "full qualitative and quantitative evaluation by
technical experts" of Airspace 2000 (which includes Class G
Airspace). Such an evaluation was proposed by the acting Chairman
of CASA in a letter to the Chairman of Airservices Australia
following the CASA Board meeting of 25-26 September 1997".
CASA Response.
With the exception of the late changes made on 4 November 1998,
the Authority considers that the safety case addressed the
principal concerns mentioned above. The main hazards were
identified and consolidated in the updated safety case, the
remainder being contained in its appendices.
A multiple risk analysis of the Class G Demonstration was
undertaken in line with accepted methodologies, any one of which
would normally be considered as adequate, The analysis of risk
associated with the Class G Airspace Demonstration included:
1. Quantitative modelling based data, validated models, and
analysed assumptions (Airservices Safety Case - included in CASA
Safety Case);
2. Experienced judgement (AEP) and UK CAA Review (see CASA
Safety Case); and
3. Trial Implementation (BASI was involved in the monitoring
process and was provided with regular reports).
c)"The pilot education programs of both CASA and the aviation
industry, as primary mitigators for hazards associated with the
airspace changes, were not implemented effectively (in terms of the
originally planned program, as well as the changes introduced
subsequent to the issue of Aeronautical Information Publication
Supplement 48198). A lack of pilot knowledge continues to be a
major operational safety concern".
CASA Response:
Noted. A comprehensive pilot education package was mailed out to
every AOC holder, some six weeks prior to the original commencement
date of the demonstration (the cost of which was $.5M). However, it
is acknowledged that there were deficiencies with respect to pilot
education in some quarters and that, with hindsight, such issues
could have been better handled by all concerned. Some changes to
airspace design were introduced two weeks prior to implementation,
but these were minor in comparison to the overall package and did
-not involve changes to pilot procedures. The Authority sent
information on these changes to all pilots licence holders.
d)"There has been a lack of support from elements of the aviation
industry for the conduct of the demonstration. Such a lack of
support had been recognised by CASA and a UK Civil Aviation
Authority review team (engaged by CASA), as a significant risk to
the success of the demonstration".
CASA Response.
Noted. As pointed out by BASI, both CASA and the UK CAA Review
Team recognised the apparent lack of support by some elements of
the aviation industry and the potential risk to the success of the
demonstration. It is considered that there might have been greater
industry support had there been more active industry involvement
earlier in the proceedings leading up to the demonstration which,
in turn, would have probably led to better understanding and hence
pilot education in the industry.
e)"There are continuing problems associated with congestion of the
NAF, a planned primary mitigator for hazards associated with the
changes. This frequency congestion can prevent the transfer of
vital information between pilots".
CASA Response:
Problems of congestion on the NAF were identified as a potential
hazard prior to the demonstration but it was determined that this
hazard could only be assessed fully during the course of the
demonstration. This was covered in the report prepared by the UK
CAA. This matter was also raised, and addressed, in CASA's
monitoring reports which showed that congestion was limited to two
periods of short duration at peak times each day. Some of the pilot
reports received, from aircraft operations conducted at higher
altitudes, indicated higher levels of congestion than was observed
by CASA staff.
f)"The Airspace 2000 plan proposed the introduction of Class E
Airspace corridors through Class G airspace on any route where
traffic density required, or where such corridors were requested by
industry. These E corridors were a planned mitigator against the
removal of DTI, but were not implemented for the Class G Airspace
Demonstration".
CASA Response:
It would appear that there is a misunderstanding of the concept
with respect to E corridors. Class E Airspace was available from
8,500 FT above the entire area covered by the Class G Airspace
Demonstration. 'E' corridors were planned as a mitigator for the
removal of DTI further west, outside the radar environment.
g)"There are safety deficiencies associated with the current
frequency management procedures, particularly during departures and
arrivals at uncontrolled aerodromes (as shown in the occurrences
described above). Pilots are required to monitor a number of
different frequencies during these high workload phases of flight
and may consequently not receive critical radio transmissions, or
may receive late advise of other traffic".
CASA Response:
Noted. This is a complex and controversial issue. It is
acknowledged that there were some workload difficulties associated
with frequency management. The changes introduced on 4 November
1998 which mandated the M13Z frequency in MTAs alleviated the
problems for arriving/departing RPT flights.
h)"Pilots and air traffic services staff have been advised of
changes to the demonstration through numerous Notices to Airmen,
which have been issued In an ad hoc and reactive manner. This
continues to cause confusion among pilots and air traffic services
staff".
CASA Response:
This criticism is acknowledged. At the time when the
demonstration was terminated, action was well advanced to issue a
replacement AIP Supplement (intended to be 69198). The intention
was that this AIP Supplement should replace AIP Supplements 48198
and 66198, together with all of the NOTAM that had been issued. The
intended replacement AIP Supplement consolidated all material into
a single document, the purpose being to minimise the risk of
confusion.
i)"As yet, the investigation team has not found evidence to
indicate that
CASA's safety case process has considered the following safety
issues
associated with the Class G Airspace Demonstration:
The full impact of each of the changes to the Class G Airspace
Demonstration procedures and design that were implemented
subsequent to the issue of Aeronautical Information Publication
Supplement 48198 on 13 August 1998";
CASA Response:
Changes introduced subsequent to the issue of AIP Supplement
48198 were not subject to the safety case process because they were
introduced to address concerns raised by the airlines which,
principally, focussed on problems associated with frequency
management and workload. It is acknowledged that changes introduced
after the demonstration commenced were not subject to a formal
safety analysis process.
"The full impact of the removal of DTI, particularly the
potentially detrimental effects on situational awareness for VFR
pilots (for example a VFR pilot may now need to monitor two or
three frequencies to maintain awareness of IFR traffic, when
previously only one frequency was required)";
CASA Response.
The contention that the full impact of the removal of DTI was
not subject to a formal safety analysis is disputed. The original
safety case prepared by Airservices in 1996 addressed this issue in
detail. It is also noted that BASI has stated that "it is not
possible at this stage to compare the overall safety level of the
Class G Airspace Demonstration with that of the previous
systems.
In terms of situational awareness for VFR aircraft, there was no
change from the one frequency they were required to monitor
enroute. There were, however, other complications introduced by the
removal of Flight Service, such as coordination with ATC for
clearances through restricted areas.
"Operational difficulties associated with two concurrent sets of
procedures, one for the demonstration airspace and one for the
existing system".
CASA Response:
The issue of demonstration area boundaries was identified and
given careful consideration by the safety education cadre and was
given prominence in the safety education material which was
produced. The Authority is satisfied that adequate procedures
existed for the en-route situation but acknowledges that the issue
of boundary aerodromes was not addressed until after the
commencement of the demonstration.
j)"As yet, the investigation team has not found evidence to
indicate that there was a clear transfer of roles and
responsibilities from Airservices to CASA for the management of
Airspace 2000 (which includes Class G Airspace)";
CASA Response.
The Airspace 2000 Program Definition Plan clearly defines the
management structure for the project and the roles of the
respective agencies.
"A comprehensive and systematic analysis of pilot tasks under the
Class G Airspace Demonstration model (including an examination of
the combined effects of all the changes on workload, situational
awareness and crew coordination, as well as the development and
testing of specific operational procedures)";
CASA Response:
This issue was the subject of extensive discussion with airlines
prior to the commencement of the demonstration during the course of
which pilot workload scenarios (including timings and radio
procedures for two pilot operations) were considered, the CASA
safety case refers. It is true to say that a comprehensive and
systematic analysis of pilot tasks was not carried out. However,
advice from the UK CAA Review Team was that this could not be
resolved prior to the demonstration and that it could only be fully
addressed by close monitoring of the demonstration.
"A systematic comparison of the Class G Airspace Demonstration
model (including consideration of the Australian aviation system
and environment) with appropriate overseas airspace systems";
CASA Response.
No formal comparison of the Class G Airspace Demonstration model
with appropriate overseas airspace systems was carried out.
However, it was widely understood that the Demonstration model was
very similar to the airspace models implemented in a number of
other countries. Moreover, an ICAO compliance matrix was prepared
(see attached).
It should also be noted that the UK CAA report drew a comparison
between the Australia Demonstration model and the British Class G
airspace.
In addition, a considerable body of work was developed,
subsequent to the failed implementation of 11/11/93, which
extensively relies on comparisons with overseas systems. This
material was taken into consideration in the development of
Airspace 2000.
"A clear rationale for conducting the demonstration prior to the
introduction of TAAATS"; and
CASA Response:
In response to the BASI Interim Recommendation No. IR970112,
CASA sought to maximise the use of available radar coverage in the
Canberra - Ballina area, especially where RPT flights were
concerned.
Implementation of the Class G demonstration is not TAAATS
dependent and the introduction of TAAATS would not have required a
change to the Class G Demonstration procedures. It is a commonly
held misconception that TAAATS incorporates an airspace design.
This is incorrect. TAAATS will be capable of supporting multiple
designs and classes of airspace.
CASA was concerned to neither delay nor disrupt TAAATS and
sought to implement the Class G Demonstration in the window of
opportunity offered by Airservices.
"A proactive evaluation of the effectiveness of the pilot education
program prior to the introduction of the demonstration".
CASA Resonse:
There was no proactive evaluation of the effectiveness of the
pilot education programme prior to the commencement of the
demonstration. However, in accordance with the communication
strategy, a number of information sessions were held to assess the
effectiveness of the training material. In addition, a 'hot line'
was put into operation several weeks prior to the commencement of
the demonstration which provided further feedback on frequently
asked questions and areas of misunderstanding.
The establishment of monitoring processes (such as a 'hot line',
ESIRs, pilots' reports, airborne monitoring etc.) once the
demonstration had commenced, provided a variety of inputs from
which it was possible to make an assessment of the effectiveness of
the pilot education programme. The most common areas of difficulty
were identified and the information repeated in Aiming Higher which
was distributed to all pilots.
