Additional Thoughts on Airspace Management

Aircraft within controlled airspace will notice a marked reduction in radio workload. The controller can see everything on the screen he used to have to keep asking questions about. Ground speed, altitude, identity. More traffic can be processed as the controller has all the menial work done for him by the machine. His thinking time is greatly increased, safety is enhanced.

The radar, however, is not just tracking aircraft inside controlled airspace. Vast areas of uncontrolled airspace will come within the coverage of the new radar chain as it stretches from Cairns, in an unbroken line along the East Coast, as far as Adelaide.

But we have a problem. Under the CAN. s present structure, services OCTA are provided by Flight Service Units or Centres. These are separate from the Air Traffic Control Centres and are equipped with radio, communication links, and maps, but very little else. It is costing the CA A somewhere in the region of $20m to automate the Flight Service displays. The cost of also providing radar would be astronomical. It would be tantamount to creating two identical, but separate, air traffic control systems. Not a very cost effective solution, I think you will agree.

Added to this, the majority of OCTA users are Private, Airwork and third level airlines. Traditionally the most cost sensitive of aviators and also the most vociferous about over provision of services. So, how do we provide a better service to this category of customer at the lowest cost, or preferably no extra cost at all.

What I believe is required is a redesign of our airspace structure. The strict divisions of OCTA and CTA must disappear and be replaced by a total airspace concept within which different levels of service are provided by the same controller on the same frequency, in accordance with customer requirements. On the one frequency, it would be possible to hear aircraft receiving positive control, limited control and just flight information.

The new structure would preferably be introduced about one or two years after the new radar equipment is operational. To allow for detailed planning, an educational process, equipment teething problems, trials, training, etc.

What I propose has been borrowed from the United States, modified slightly to fit our requirements, but nonetheless is a proven working model, already operating safely.

New Airspace Model

PositiveControl Area (PCA)-AII traffic separated according to present standards (IFR only in the US but we can still accommodate VFR).

Lower level would rise to FL245 in outback areas and progressively lower as major centres were approached, eventually merging with Control Zones much in the way the present CTA steps do. See the following examples:

15,000 feet – (Outside Terminal Manoeuvring Areas)

IFR- Separated from other IFR; Fly even levels (50, 60, 70, etc. ) using semi-circle rule; Traffic advisories on uncontrolled VFR aircraft; Altitude encoding transponder required.

VFR – No separation; Fly 500′ levels (55, 65, 75, etc. ) using semi-circle rule; Altitude encoding transponder required; Flight Information Service; Traffic advisories on request controller workload permitting.

Change of flight procedures permitted where automated flight data handling is available to controllers.

5,000 feet – (Outside Terminal Manoeuvring Areas)

All aircraft fly at quadrantal altitudes where possible.

AFIZ – Traffic information service to RPT jets only.

Others- Flight information on request, possible Full SAR flight and non- AFIZ areas following; Traffic advisories to transponder equipped aircraft onrequest, controller workload permitting; Transponder not required unless operating into designated airport TMN.

All aircraft would get a full separation service on entering PCA areas near major airports. (Mode C transponders required.)

The full range of services would be offered vertically through the airspace from one control console, easin·g transition from one environment to the other. Sectorisation would be done purely on traffic density and not be service, as at present.

The proposal has the major advantage of offering, within each height band, the level of service appropriate to the type of aircraft operation and the capability of the customer to pay. It is also efficient in the use of CA A resources, staff and equipment.

A couple of examples might help:

You leave Moorabbin on a Sartime plan, heading north west through the lane. You listen out on ML Radar {Low Altitude Service) frequency (an additional sector responsible for assisting aircraft through the complicated ML airspace) You are navigating but, having set the nationwide ‘Sartime below 5,000 code’, you are automatically tracked by the radar and your progress is monitored clear of the Control Zones by the controller. The frequency is quiet so you identify yourself, ask for and get a direct track remaining west of Calder Raceway and Sunbury and a climb to 3,000, an immediate benefit. You are VFR inbound to land at Sydney flying at 4,000, you have been listening out on the frequencies and have not required any service to this point. You are squawking the nationwide ‘Listening Out Below 5,000 code’. In case of emergency, radar and other assistance would be immediately available. At about 80 miles you automatically switch to SY Radar (Low Altitude Service) and report position and ETA. Your level is already displayed on the controller’s screen. He reassigns you a transponder code enabling the computer to fix your call sign to the radar label. At 40 miles you are advised clearance will not be available on the direct track and that radar will provide advisory headings and traffic information to the preferred entry point. You have still got to keep your eyes open. At 15 miles positioned on a wide right base for the new runway at Mascot you are instructed to call SY Approach for vectoring onto final. A smooth and efficient use of airspace and equipment.

You are an IFR Navajo leaving Gladstone for Brisbane. You call SN Control departing, on climb to 8,000, you can hear the patter as three RPT jets chase each other northbound. You are squawking a discrete code allocated by the computer when you flight planned with the Brisbane Central Briefing Unit (CSU). Leaving 3,000, you are automatically identified by the new SSR radar near Rockhampton. Information is passed on northbound VFR traffic indicating 5,500 on Mode C. Leaving 4,500, the controller advises the traffic is 12 o’clock 10 miles, advisory radar heading 270 to avoid. You take the heading keeping your eyes open. Two minutes later you are told the traffic has passed but to maintain 7,000 for separation with a southbound IFR Bandeirante. You will be advised if 8,000 becomes available. You automatically resume your own navigation.

In the first case radar is being used to safeguard the Melbourne TMA and give a service to GA aircraft at the same time. Automatic radar identification has relieved the controller workload and made intermittent control feasible.

In the second, the same type of radar service is efficiently positioning aircraft for Control Zone entry, to provide the minimum disruption to the Approach control service.

In the final case, third level airline and other IFR aircraft are receiving a brand new service. Provided by a controller newly freed from the exacting task of non-radar separation over Rockhampton. His spare capacity and the capabilities of the new radar are being used to the best effect.

Flight Service Officers reading this will by now be very concerned, as will every pilot who remembers the friendly, efficient service they have received from FS Units over the years. The facts of life are that the CA A is already in the process of closing all those friendly face to face Flight Service Units. The satellite based communications system has made ‘consolidation’ of these far flung outposts into major capital city centres a reality. The other reality is that the comprehensive traffic information service they are trying to give around major centres such as Sydney will become more and more difficult without radar assistance. This was evident during the early stages of the pilots’ dispute.

Contemplating the use of radar to provide traffic information raises another problem. You cannot give a person a radar display and still expect them to give ONLY traffic information. It is an utter waste if that equipment cannot be used for vectoring aircraft. Why give traffic information, when a simple heading change will solve the problem? It is also debatable whether the law would allow someone to watch, that is, allow, a collision to take place without attempting positively to intervene and prevent it. This intervention is, of course, precisely the role of the air traffic controller and is the essential difference between the two services the CA A provides.

The answer to this one is easy. Train FSOs to be Air Traffic Controllers. It will not be the first Hme aviation technology has made redundant a very highly regarded group of professionals. The latest – Flight Engineers. This is one of the reasons for the lead time required to implement this new structure. New entrants to the CA A are already being trained to do both jobs.

There will obviously be some FSOs who, for a variety of reasons, cannot, or do not wish to, undertake the extra training required. Australia will never have the total radar coverage enjoyed by the USA, so the present system will continue outside radar coverage for the foreseeable future. The remaining specialist flight service officers will still have plenty of work.

The future of air navigation seems to lie in AutomaticDependent Surveillance (ADS). Navigation by satellite,based on US GPS and USSR Glonass, will become so widespread throughout the world that cars, trucks and buses, as well as ships and airliners will be using it. By that time, the unit cost will be low enough for every GA aircraft to be equipped and the new system can be extended to all areas of the country.

Regardless of the final arrangement of Australian airspace, the introduction of our new generation radar equipment is the time for new thinking. The concept was originally called IMAS (Integration and Modernisation of the Airways System). We should not attempt to perpetuate procedures and organisation based on what was possible with equipment installed thirty years ago. Now is the time to make these decisions, before we go too far down the old road.

(Geoff Fairless has been an air traffic controller with the CAA for 17 years. Before that he flew with the RAF. The views expressed in this article are his own and do not necessarily represent the views of the Civil Aviation Authority or the Civil Air Operations Officers Association. )