CAA Proposes New Airspace Management System

The present system is also recognised as being too labour-intensive and subsequently too costly. Air traffic staff must closely coordinate their actions under the present system, effectively reducing the capacity to handle traffic and increasing workload and costs. This in itself is a potential hazard and any initiative which will maintain or increase the capacity to handle traffic can only be beneficial to those up in the air.

Another important reason for implementing change in line with ICAO is the availability of air traffic control (ATC) equipment. The CA A has recognised that “as the complexity of equipment necessary for air traffic control (such as radar, flight data processing, etc) increases, it becomes prohibitively expensive and risky for Australia to ‘go it alone’ and design equipment for our existing unique airspace system”. Australia should take the opportunity to benefit from the development of ATC systems in leading aviation countries with ICAO based systems, such as the USA and Canada.

The adoption of an ICAO based system basically involves the replacement of the present two levels of flight management service (controlled and uncontrolled) with no less than seven levels, ranging from Class A which retains full controlled separation of all aircraft to Class G, which offers only the basic but necessary flight information services. The introduction of seven levels of service may sound somewhat confusing but it will in actual fact streamline operational standards and procedures, and prove both safer and more cost effective for all involved. And despite any suggestions that the move is simply following those made in the United States and Europe, this is not so. The ICAO system is recognised as being the best for Australian airspace management and several unique features will remain where it is believed necessary. For instance, jet aircraft operating between majorcentreswill continue to be provided with full positive separation from all other aircraft. This is not the case in North America.

A brief description of the seven levels of service under the ICAO classification is needed. The seven levels are, as noted, divided into Classes A to G. There is very little difference between Class A and the present controlled airspace above Flight Level (FL) 200. Change to this airspace did not seem warranted. Positive separation of IFR aircraft will continue to be provided and, as is the case now,VFR trafficwill only be permitted in Class A with special approval.

Class 8 is essentially equivalent to all current Australian-controlled airspace below FL200 excluding general aviation airport (GA AP) control zones. Positive separation will be provided in airspace above 10,000ft in terminal areas surrounding major radar equipped airports and in busy air routes above 10,000ft.

Class C covers all radar terminal areas below 10,000ft surrounding major airports such as Sydney or Perth. IFR aircraft will be provided with positive separation and VFR aircraft will receive traffic advice and conflict resolution.

Class D is essentially similar to Class C but will cover the present GA airport control zones and many country controlled aerodromes. It will include aerodromes where traffic density requires air traffic control to provide a runway and circuit separation service. Airports such as Coffs Harbour will utilise Class D airspace. Like Class C, IFR aircraft will be given positive separation and VFR aircraft will receive traffic advice.

Class E airspace will be used around aerodromes where traffic is so light that an air traffic control tower is not warranted, but where the local weather conditions or the nature of the traffic dictate the provision of IFR positive separation. An example of this would be Dubbo where density is not great but IFR traffic often utilises the airport. The provision of some low level Class E airspace may be warranted within radar coverage areas or in other selected areas if required by the industry.

Class F is very similar to the present uncontrolled airspace. It will cover areas where traffic advisories to IFR aircraft are not warranted because of the low density of traffic in the area. Aircraft will receive radar advisory services, the use of which would ease the transition from uncontrolled to controlled airspace.

Class G will cover all airspace not allocated to other classes.

Essentially this will include most uncontrolled airspace, notably the outback areas where airspace density is negligible. The only service provided will be a flight information service.

There remains one other airspace classification not covered military airspace. At present, just how this will fit into the system remains unclear, though negotiations are underway for the military to “remove apparent barriers between military and civil airspace”. In effect, the CAA would like most military airspace to be covered by the new system, with military aircraft making more use of civil air traffic control services as is the case in the United States.

The introduction of ICAO based airspace classifications cannot be done effectively without changes to airspace management standards and procedures. It is only by introducing new standards and procedures that the greatest gains in efficiency and service can be realised. One of the key proposals is that from November 1992 all aircraft operating in airspace Classes A to F within radar coverage will be required to carry and use radar transponders and that when operating above 10,000ft AMSL or within 30nm of radar airports, the transponders must have Mode C altitude reporting capability. This will add to costs for the aircraft owners but the CAA is of the opinion that use of trans ponders will significantly improve the safety margin when flying, particularly when operating in busier sectors such as around Sydney or Melbourne. It will also provide ready access to direct tracking, navigational assistance and precise traffic advice. Air Traffic Control will be better able to track aircraft and detect those that stray into restricted zones, and see and avoid separation will be supplemented and made safer. Waivers of the transponder requirements will be available for aircraft which have only an occasional need j to operate in radar areas, for example when positioning for maintenance.

There is a list of other proposed standards and procedures changes, several of which will be listed. It is proposed, for instance, that the Australian ‘quadrantal’ table of cruising levels be abandoned in favour of the ICAO ‘semi-circular’ rule; Australia is at present one of just three countries not to use the ICAO table. The CAA lists vertical separation as an inherent safety feature of the ICAO table of cruising levels, allowing 500ft separation between IFR and VFR aircraft, thereby permitting greater airspace usage in visual meteorological conditions (VMC). 1,000ft separation is still provided between IFR flights on opposite tracks.

The present SARwatch system based on full reporting will be extensively modified. The CAA believes the present system adds substantially to the operating costs of the ATS system without improving safety in any measurable way. It is therefore proposed to retain full watch for flights only in Classes A and B (outside radar coverage) and for IFR flights in Classes C, D and E airspace. Full reporting SARwatch will not be available to VFR flights in Classes C to G airspace or for IFR flights in Class F or G airspace.

With the use of the recently purchased Local User Terminal (LU T) capable of receiving and processing information from search and rescue satellites, however, SAR services will not suffer. All aircraft will be required to carry an emergency locator transmitter except when clearly not needed, such as in scheduled public transport over the mainland or in aerial agriculture. By utilising LU T, SAR authorities will be able to locate the position of a transmitting emergency beacon within a maximum of four hours.

In order to simplify flight planning and notification requirements, the CAA intends to adopt the ICAO Flight Plan Format for both domestic and international flights. It is proposed that compulsory notification of flight details to the CAA be limited to IFR flights in airspace Classes A to F and to VFR flights in Class B. In some cases flight plans may be required for operations in Air Defence Identification Zones. Although VFR aircraft will not be required to submit a flight plan prior to operating in Classes C or D airspace, they will be required to establish two way communication with control and advise their intentions before entering the airspace and comply with all ATC instructions. Pilots choosing not to notify the CAA of flights in other airspace classes will be advised to leave a flight itinerary with a responsible person.

Air traffic control services in classes where this is provided will experience some change, with formal ATC clearance being replaced by an ATC instruction under some circumstances to simplify the process and reduce frequency congestion. It is envisaged that: there will be no change to the way clearances on the ground at control tower equipped aerodromes are issued; for aircraft en route, the controller will issue instructions to the pilot designed to maintain separation, and approval to proceed beyond a certain point may be denied or instruction given that the aircraft alter track and/or altitude or make further position reports; standard radio fail instructions will be published in pilot reference documents; an onwards clearance normally issued to an aircraft completing Airwork inside Class A, B or C airspace will be replaced by a control instruction or missed approach instruction.

Local procedures will be developed to expedite traffic flow. Under the new arrangements, the Control Tower will be responseible for airspace management within prescribed lateral and vertical limits. By utilising visual separation wherever possible,local procedures may be developed and negotiated between tower managers and locally based VFR operators. These procedures will be aimed at enhancing freedom of movement in the local area with the minimum of interaction with arriving and departing traffic and minimum requirement for exchanges on the tower frequency. The local procedures will be formalised through letters of agreement.

Though the above are not all the proposed changes to the airspace management system, they are some of the more important and they certainly do give a firm indication of what can be expected. But what will the changes mean to those in the industry.

For airline pilots there will be little apparent change. On a flight from Sydneyto Melbourne, for instance, the aircraft will be under radar surveillance throughout the flight and will receive positive separation from all other aircraft. However, with the carriage of Mode Ctranspondersby all aircraft within 30nm of the two major cities, the flight will be considerably safer with vastly reduced chances of collision during ascent and approach.

An example of what the new system will mean to IFR pilots is given by the CAA. If an IFR aircraft takes off from Gladstone for Brisbane and is planning to cruise at 9,000ft in the new advisory airspace, thepilot will call Brisbane radar on departure, squawking a discreet code. Leaving 3,000ft the aircraft will be identified on the new SSR radar near Rockhampton and the pilot will be advised of traffic and given advisory headings to avoid it if necessary. The aircraft will cruise at a level segregated from VFR traffic. Close to Brisbane the aircraft will be transferred to a control frequency and will receive instruction to fit into the flow of the traffic. The pilot will need only to adhere to control instructions.

To the VFR pilot, the first noticeable difference will be the simpler flight plan form which needs only the aircraft identification, a few necessary details and an indication of flight route and time of arrival at final destination, even if more than one landing is anticipated. The aircraft’s transponder will enable it to be tracked on radar and the pilot will be offered direct tracking and an early climb to cruise altitude if possible. Leaving radar airspace, the pilot will tune to the operational information service frequency to amend the flight plan, to seek updated weather or NOTAMS and cancel SARwatch at the end of the flight. It is expected that a sharp reduction in pilot workload will be noticed. If arriving at a country aerodrome, the pilot will announce intentions on a common traffic advisory frequency to arrange separation from other aircraft.

Reduced workload and increased efficiency is one thing, but what about safety? A short answer is that the new system will offer increased safety margins. As it will be implemented in conjunction with new technology, such as increased radar coverage and the use of transponders, aircraft will be both easier to track and easier to control. Reduced workloads of both pilots and controllers will increase the capacity to concentrate on control and avoidance, while the use of satellite technology will improve the SAR system.

The changes will naturally affect air traffic controllers and flight service officers in more ways than just reducing their workload. To successfully implement the changes, it will inevitably mean the integration of Air Traffic Control and Flight Service and the development of a new employment structure. _ With reduced workload and the combining of often duplicated functions, there will be a need for fewer personnel in the long run and retraining of those who remain to understand the system. The CAA is presently negotiating with the two unions involved to facilitate change. Though some opposition has been met, it is expected that common sense will prevail and cooperation will be achieved to successfully implement the new system.

The new airspace management proposal is a much needed initiative by the CAA. It should decrease workload:for many sectors of the aviation industry, should reduce costs and should make flying markedly safer. Just how long itwill take to implement is a matter of conjecture. Some aspects of the proposal, such as the establishment of two new flight lanes south of Sydney, could be implemented within two years. Others could take longer, perhaps five years being a likely target. What is known is that the new system will definitely be implemented and, according to CAA Chairman Mr Dick Smith, a final decision on the necessary standards and procedures changes will be made by the end of the year.