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Interim Recommendation issued to: Department Of Transport

Recommendation details
Output No: IR19980256
Date issued: 08 December 1998
Safety action status:
Background:

SUBJECT

Safety Concerns Relating to the Class G Airspace Demonstration.


BACKGROUND

Australia is harmonising with elements of the International Civil Aviation Organisation (ICAO) air traffic services standards and recommended practices. ICAO has developed an alphabetical airspace classification system ranging from A to G. Each classification indicates the level of air traffic control service provided, with Class G airspace having the least service.

The plan for Australia's move to this harmonised approach is known as "Airspace 2000". The implementation of Airspace 2000 commenced on 26 February 1998 with the demonstration of Class E airspace in the Canberra-Ballina region.

Airspace 2000 is altering some long-standing practices unique to the Australian aviation industry.

An important aspect of the Airspace 2000 program is its integration with The Australian Advanced Air Traffic System (TAAATS).

On 22 October 1998 the Civil Aviation Safety Authority (CASA) commenced a demonstration of new operating rules and procedures for Class G Airspace. The demonstration is being conducted in the Canberra-Ballina region in Class G Airspace below 8,500 feet.

Key features of the demonstration are that it:

removed directed traffic information (DTI) provided by flight service;

introduced a national advisory frequency (NAF); and

introduced a radar based traffic information service subject to radar coverage and air traffic controller workload.

The Bureau of Air Safety Investigation (BASI) is conducting a systemic investigation of the demonstration. The investigation is part of its normal systems safety investigation role.


SAFETY DEFICIENCY

The overall program management of the Class G Airspace Demonstration has been deficient because critical safety issues have not been addressed.


FACTUAL INFORMATION

Related occurrences

9805078 - The crew of a BAe Jetstream was maintaining the aircraft at 5,000 ft for separation from a descending Beechcraft King Air. The sector controller transmitted radar information on the Jetstream to the pilot of the King Air. This transmission was not acknowledged by the King Air pilot and was subsequently reported to have been over-transmitted by another pilot. The King Air was observed on radar to descend through the level of the Jetstream. The two aircraft passed each other with approximately 600 ft vertical separation and 0.5 NM horizontal displacement. The investigation is continuing.

9804984 - Prior to departing Lismore the pilot of a Beechcraft King Air transmitted taxi and departure reports on the Lismore/Casino/Ballina mandatory broadcast zone frequency (MBZ) but received no replies. He then contacted Brisbane Centre for a radar information service and was advised that there was no radar observed traffic. The pilot of a SAAB 340, which had just departed Casino, was monitoring the Brisbane Centre frequency and heard this report. He then contacted the pilot of the King Air to arrange separation. Shortly after, the pilot of the King Air saw the SAAB 340 pass underneath his aircraft. Subsequently, the pilots established that they had both transmitted the required MBZ reports but neither had heard the other's transmissions. The SAAB 340 pilot was not required to monitor the Brisbane Centre frequency, but by doing so he enhanced the crew's situational awareness. The investigation is continuing.

In both of these incidents, prior to the introduction of the Class G Airspace Demonstration, the crews would have been alerted as to each other's existence through the provision of directed traffic information.

Project monitoring

As part of the Bureau's monitoring of the Class G Airspace Demonstration, an investigation team was formed to collect and analyse information relating to the development and conduct of the demonstration. The team conducted interviews with staff and obtained data from the Civil Aviation Safety Authority (CASA), Airservices Australia and the aviation industry.

The Bureau's investigation team has noted that CASA had a safety case process for the Class G Airspace Demonstration, and that CASA is closely monitoring the operational progress of the demonstration.

However, the Bureau's initial analysis of the information obtained identified a number of major safety concerns:

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.

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.

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 48/98). A lack of pilot knowledge continues to be a major operational safety concern.

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.

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.

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.

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 advice of other traffic.

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.

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 48/98 on 13 August 1998;

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); and

operational difficulties associated with two concurrent sets of procedures, one for the demonstration airspace and one for the existing system.

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);

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);

a systematic comparison of the Class G Airspace Demonstration model (including consideration of the Australian aviation system and environment) with appropriate overseas airspace systems;

a clear rationale for conducting the demonstration prior to the introduction of TAAATS; and

a proactive evaluation of the effectiveness of the pilot education program prior to the introduction of the demonstration.

It is not possible at this stage to compare the overall safety level of the Class G Airspace Demonstration with that of the previous system. However, due to the safety concerns listed above, the following interim recommendations are made.

For further information please see report `Systemic Investigation into the Class G Airspace Demonstration'.

Output text

The Bureau of Air Safety Investigation recommends that the Department of Transport and Regional Services, the Civil Aviation Safety Authority and Airservices Australia review and clarify the roles and responsibilities of the respective organisations in relation to the regulation, design and management of airspace to ensure the safety integrity of the aviation system.

The Bureau of Air Safety Investigation simultaneously issues this interim recommendation to the Civil Aviation Safety Authority and Airservices Australia as IR980261 and IR980257 respectively.

The Bureau of Air Safety Investigation simultaneously issues the following related interim recommendations to the Civil Aviation Safety Authority:

IR980253 - The Bureau of Air Safety Investigation believes that the Class G Airspace Demonstration has served its purpose. In the light of the safety concerns identified by this investigation, BASI recommends that the Civil Aviation Safety Authority should now terminate the demonstration.

The results of the demonstration should be subject to a comprehensive evaluation that specifically addresses the safety concerns identified by BASI.

The evaluation process should take into account the time required to:

review and analyse the demonstration;

refine the model where required and conduct a proper safety analysis; and

provide a comprehensive and effective education and training program for any subsequent changes to Class G Airspace.

If this is not achieved, the deficiencies identified in this investigation are likely to be repeated, thereby seriously compromising the successful introduction of future changes to airspace including reintroduction of Class G Airspace incorporating Radar Information Service and National Advisory Frequency.

IR980260 - The Bureau of Air Safety Investigation recommends that the Civil Aviation Safety Authority review program management policies and procedures for current and proposed changes to the aviation system, in the light of experience gained from the present Class G Airspace Demonstration.

Initial response
Date issued: 04 November 1999
Response from: Department Of Transport
Action status: Closed - Accepted
Response text:

The Bureau of Air Safety Investigations review of the Class G Airspace demonstration made an interim recommendation (IR980256) that:

"The Department of Transport and Regional Services, the Civil Aviation Safety Authority and Airservices Australia review and clarify the roles and responsibilities of the respective organisations in relation to the regulation, design and management of airspace to ensure the safety integrity of the aviation system."

The Department conducted a Review of Roles and Responsibilities for the Regulation, Design and Management of Australian Airspace. This report responds to this interim recommendation.

 

ATSB response:

ATSB Note: The Bureau has been provided with a copy of the report.

 
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Last update 01 April 2011