Does Air Traffic Control Affect The Economy?

Firstly the Pilots and their aircraft – they are the main variables that Controllers need to evaluate in any decision they make.

When the last AACC was commissioned on Australia in 1972, Controllers had three compatible aircraft as the main component of any sequence. The 8727, the DC-9 and the F27. Two similar type jets had to be 15nm apart on the cruise to allow an unrestricted descent for both aircraft and a spacing of 5nm on final. A higher speed on descent was available from both jets from approximately 140nm and in each case it was an acceleration into the descent. This meant that there was a capability when sequencing, to have a high speed effect over a long time period and this was used to gain a slot or two at the start of the sequence.

Profiles and compatability no longer exist. The 8767 is not compatible with the A300 and their differing operating flight levels mean that with the two airline policy, there is normally conflict. The 8737 does not seem to fit in anywhere although it has the same profile as a DC-9. Despite all calculations on Mach number, Indicated Airspeed or True Airspeed, any Flow Controller will agree that the DC-9 is faster over 120nm than the 8737.

The 15nm that was necessary on a cruise for an unrestricted descent for like-type jets has now opened up to 20nm due to present profiles. Instead of descending at 140nm and accelerating, jets now stand into 85nm and decelerate and drop with a faster rate of descent. This means that the following aircraft will close on the descent with approximately 6000 feet between the two aircraft and a resultant closing in True Airspeed. Any increase is only from 85nm not 145nm, a loss of 8 to 10 minutes for that speed to take effect. This is if the speed is forthcoming. There are some pilots of all companies both Domestic and International who will promise the world to get in front of the queue and then give it away at 30nm; the resulting shunting effect way back up the sequence has been experienced by all pilots when they receive late speed reductions at embarrassing times.

Pilot proficiency is the greatest asset the Controller has in his traffic management. Present schedules force aircraft into holding stacks and the ability of the pilot to achieve a Stack Departure Time on time is essential; in Europe, one of the requirements for an Instrument Rating is to depart a stack plus or minus 20 seconds. The effect of a late departure of one minute may not seem much to one aircraft but if there are six aircraft behind him, there is an immediate loss of seven minutes of fuel to the sequence, with the further problem that patterns might have to be adjusted, adding more to the loss.

With the current emphasis on fuel conservation, it is easy to see how pilots who are responsible for the economic operation of their aircraft can be affected with a type of tunnel vision with reference to individual aircraft fuel conservation. The overall fuel benefit must take precedence over individual aircraft economy in any sequence of aircraft.

On the ATC side, the Controller who has the responsibility for the overall economy is the Flow Director. This officer has the responsibility of effecting correct sequences so that priorities are achieved, and economic advantages or disadvantages are evened out, thus ensuring that the industry benefits as a whole. Decisions have to be made regarding economic benefits that are not necessarily obvious to the single aircraft affected.

The Flow has to contend with varying meteorological conditions such as thunderstorms requiring track diversions or the passage of Frontal conditions where the wind on a particular track will change from head to tailwind component in a ten minute period. The only aid Flow Controllers can look forward to is the Flow computer being developed in Sydney. This was due for field trials in late August and spent at least the first six weeks in a corner of the Sydney AACC due to the lack of a part. Even now that it is up and running, it is still only a tool for Flow Controllers as its inputs are minimal, for example, the global winds used are mainly those that are forecast, with individual updates from aircraft reports. The descent profiles are those advised by the companies and not those that might be flown by individual pilots in command. The industry has invested in new aircraft with an emphasis on fuel conservation, whilst Air Traffic Control stays in 1972 or earlier. Just like buying a new car that uses less petrol so that you lose less whilst standing in the same slow traffic at the same traffic lights. The answer is to improve the traffic management system.

Because the Flow Controller works as an individual, it can be seen that mistakes can and will be made and if a sequence is programmed loosely, the resultant loss to the industry is thousands and just in that one sequence.

Individual traffic controllers affect the economic handling of traffic by the mere fact that they have to control aircraft direct, therefore the efficiency of any traffic management relies on the Controller’s ability and workload capacity; if the controller is experiencing an ‘OFF’ day, this could cost the industry thousands of dollars. It is all the more amazing that this individual often has to control this traffic for seven hours without a break.

The industry pays the penalty for the lack of any Air Traffic System in Australia and in particular for the lack of any new technology to assist Air Traffic Controllers in their task.

What equipment do controllers currently have to accomplish their task? In the RECCE column of the September issue of “Australian Aviation”, mention is made of antiquated ATC equipment with particular reference to Sydney. It must be realised that the Sydney Area Approach Control Centre has the most modern displays, the most modern equipment and is the most modern Area Approach Control Centre in Australia. It was commissioned in 1972 and since then no update has occurred in ATC facilities in any Civil Area Approach Control Centre anywhere in Australia. Brisbane was commissioned in 1969 and Melbourne in 1967. Adelaide and Perth have never had a real Area Approach Control Centre and as well as operating with slow scanning radar, and feeding darkroom equipment, their working conditions to quote the Department of Aviation in reference to Kalamunda, “leave a lot to be desired”. Adelaide, Melbourne and Perth need new equipment to remain operational. Their Radar uses valves that are in short supply and the Radar equipment costs more to maintain than replace. Sydney, of course, needs new equipment. Most airlines have updated their fleets and technology since 1972 and Air Traffic Control should have kept pace. One thing that must be noted is that new radar or display units for Sydney will not move the traffic any quicker or obviate holding and delays. When San Francisco went to a single crossing runway configuration to enable maintenance on its parallel runway system, Sydney handled 25% more traffic than San Francisco. Sydney can handle in excess of 55 movements per hour and new Radar facilities could not make any noticeable improvement on that rate. Sydney’s problem is concrete time and that problem can only be solved by extra runways and proper entry and exit taxiways.

So where does Air Traffic Control stand with regard to new facilities? Adelaide, Melbourne and Perth will commission their new AACCs with the new ATCARDS System in mid-1985, mid-1986 and early 1987 respectively. They were planned to open in 1981, 1982 and 1983. Why the delay, surely something as important as Air Traffic Control should have the best as soon as possible. Cost recovery must take some blame, as every new facility requires cost justification. The new Area Approach Control Centres can benefit aviation as they will enable controllers to provide a better and more efficient service. The Department’s philosophy of reducing staffing levels has led to two Regional Directors stating that Air Traffic Control will enter these new facilities without the required extra staff as the present staffing levels are providing an adequate service. Why provide an adequate service when we will have the equipment to provide a better one?

In 1983 QANTAS planned to update its fleet for a cost of $846 million. For 1% of that amount it would be simple to install 8 or 9 Secondary Radar units with ranges of 220 miles and cover most routes. This would allow direct tracking and the use of optimum cruising levels. It seems easy to talk in millions on the commercial side of aviation; the replacement ATCARDS displays for Melbourne and Adelaide came to a grand total of $11. 5 million. Another large figure that has been quoted recently is a loss of $5. 8 million on TAA operations for one year due to Air Traffic Control delays.

Do the airlines recognise the effects of their scheduling? In February 1976, two members of The Professional and Technical Committee of the Civil Air Operators of Australia attended an Industry meeting on Fuel Conservation. We produced figures obtained from the previous day’s company schedules at Melbourne. They showed that, should every aircraft present itself to use the runway as scheduled and the runway and airspace was used to maximum capacity, then without any delay generated by Air Traffic Control ability or equipment, the delays incurred would have been, for arrivals, 4 hours 59 minutes and for departures, 6 hours 56 minutes, a grand total of 11 hours and 55 minutes of scheduled delays – not Air Traffic Control delays. Only one aircraft is allowed to use the runway at one time – not 7 as the schedules seem to think. On that day in 1976, 347 scheduled movements had a built-in delay of 715 minutes, indicating an average scheduled delay of roughly 2 minutes. A similar exercise was carried out on 19 October, 1984. The result was that although there were only 262 (as opposed to 347) movements, there were built-in delays totalling 599 minutes (9 hours 59 minutes) with an average delay per aircraft of 2. 3 minutes.

Remember, this is only for Melbourne for one day, think of Australia for one year! If the operators applied that 2. 3-minute delay per movement to their factors when calculating delay costs it would bring about a significant reduction in their claimed operating losses regarding Air Traffic Control delays; and one much closer to the truth.

The final irony is that the airlines have updated their fleets and procedures to achieve optimum efficiency mainly through fuel conservation and then Air Traffic Control uses their day-to-day operations for on-the-job training of controllers. Why should Air Traffic Control feel jealous of the excellent flight simulators used for pilot training when approach controllers can use the daily commercial traffic to train? Any mistakes in sequencing, any delays in descent that result in unnecessary spooling up of the engines will be paid for by the operators. Imagine hearing. “Good morning, ladies and gentlemen, this is your Captain speaking. On departure from Sydney we will simulate an engine failure, followed by a low-level circuit and a touch and go before proceeding to Melbourne. “.

All the preceding points mentioned are detrimental to the economy, so how does Air Traffic Control affect Economy in Aviation? The answer is that in its present state, it affects Economy more than it should.

John Botwood has been on the Professional and Technical Committee of the Civil Air Operators of Australia for more than twelve years. This article was written while he was Vice President and Chairman of the Technical Committee, a role that gave him a unique insight into the workings of the ATC system Australia-wide.