IFATCA - The Controller - May 1971

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Air Traffic Control in the 70' s

Ferranti have done the groundwork The steadi l y increasing volume of air traffic is prompting many c ivil aviation authorities to make an urgent re -apprai sal of control methods.

For many a irports a nd ai r traffic control systems. the Seventies are going to demand much more sophisticated systems than those currently in use.

Th e d esign of effective com puter based systems for air traffic control demands considera ble experience and a close knowledge of A TC procedures. Ferranti have that experience and know ledge. They have been engaged in the design and development of A TC systems for over 12 years, and were in fact the first company to apply comp uters to air traffic control in the U.K. This was at the Oceanic Control Centre at Prest wick, w here a Ferranti computer was inst alled to evaluate new so lutions to the A TC problems of t he North Atlantic.

Experience with simulators helps to perfect operational systems Ferranti ATC simulators for the training of controllers and the eva luation of new ATC tec hniques are already w idely know n.

Contributi ng to their international acceptance has been the long list of simulation projects carried out on the equipment installed at Hurn Airport. Bournemouth, as part of the Air Traffic Control Evaluation Unit of the Board of Trade. Ferranti's unique experience with si mulators enables them to look much farther ahead in their planning and development of operational systems. This is because in designing equipment for training young controllers they have had t o anticipate future needs.

It has also given them an intimate understanding of the controller's problems. And it has increased their ability to undertake study contracts.

Ferranti MINICAP System at the London ATC Centre This system automates the major part of flight progress strip production, and was supplied by Ferranti complete with operational prog rams. It performs some of the more routine tasks of Air Traffic Control and so leaves controllers more tree to concentrate on making the decisions that can be so vital.

ATC Automation in Stages In ATC. automation is a process of steady accretion so that eventually each part will form a unit o f a complete system.

Ferranti systems are designed w ith capability for extension in mind. Cost-effectiveness does not st op w hen the next stage in expansion is reached.

Dig ital Computer At the heart of the latest Ferranti ATC Systems Ferranti were among the world leaders in developing the microminiature d igital computer, and their FM16.00B is already established as a fast, efficient computer for shipboard systems in the Royal Navy.

Now it has been chosen for a number of ATC applications including a simulator at Schipol (Amsterdam) Airport, and another at the College of Air Traffic Control at Hurn, Bournemouth.

Ferranti, with all this backg round of experience and with advanced equipment of proven rel iability, are ready to help you solve the ATC probl ems of tomorrow.

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2

IFATCA JOURNAL OF AIR TRAFFIC CONTROL

THE CONTROLLER Frankfurt am Main

Volume 10 • No. 2

Publisher: International Federation of Air Traffic Controllers' Associations, S. C. II; 6 Frankfurt am Main 60, Bornheimer Landwehr 57a.

Officers of IFATCA: A. Field, O.B.E., President; J. D. Thomas, First Vice President; G. Atterholm, Second Vice President; G. W. Monk, Executive Secretary; H. Guddot, Honorary Secretary; J. Gubelmonn, Treasurer; W. H. Endlich, Editor.

Editor: Wolter H. Endlich Publishing Company, Production and Advertising Sales Office: Verlog W. Kramer & Co., 6 Frankfurt am Main 60, Bornheimer Landwehr 57a, Phone 43 43 25, 49 21 69, Frankfurter Bank, No. 3-03333-9. Rate Card Nr. 2.

Printed by: W. Kramer & Co., 6 Frankfurt am Main 60, Bornheimer Landwehr 57a.

Subscription Rote: OM 8,- per annum (in Germany).

Contributors are expressing their personal points of view and opinions, which must not necessarily coincide with those of the International Federation of Air Traffic Controllers' Associations (IFATCA).

IFATCA does not assume responsibility for statements made and opinions expressed, it does only accept responsibility for publishing these contributions.

Contributions ore welcome as ore comments and criticism. No payment can be made for manuscripts submitted for publication in "The Controller". The Editor reserves the_ right to make any editorial changes in manuscripts, which he believes will improve the material without altering the intended meaning.

Written permission by the Editor is necessary for reprinting ony part of this Journal.

Advertisers in this Issue: AEG-Telefunken (1}; Borg-Warner Controls Ltd. (Inside Cover)· Ferranti Ltd. (2); ' Marconi Rodar Systems Ltd. (Back Cover). ' Selenia S.p.A. (13).

Picture Credit: Endlich (10, 20, 23); Frankfurt Airport Authority (18}; Germans (12); Greek ATCA (21, 22, 23, 25, 26, 27); Royal Olympic Hotel (20}.

CONTENTS The Regional Technical Work of IATA

4

Lincoln Lee

Letter from Nepal ................................... · · · ·

6

Tirey K. Vickers

En Route Speed Control Techniques ...................... .

8

A. J. Kulikowski Air Vision Industries, Inc.

10

Training the Controllers of the Future . . . . . . . . . . . . . . . . . . . . .

J. D. Thomas

11

Small Data Handling Systems for Air Traffic Control

14

T. E. Foster

Athens 1971 -10 Years IFATCA

20

Letters to the Editor ..................................... .

28

The Nurnberg Raid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

28

3

The Regional Technical Work of IATA

By Lincoln Lee

About the author A previous paper by this contributor entitled "The Seven Sins of International ATC" was published in the Journal some years ago. Lincoln Lee joined the British Royal Air Force in 1940 and was a Captain with BOAC from 1947 to 1965. He has been with the IATA Secretariat since then, and is their Regional Technical Representative, (North Atlantic/North America).

If the throttle lever in an aircraft is pushed forward, should this increase engine power or decrease it? Naive as this question may seem today, it was effectively the first question posed to the Technical Committee of IATA; and it was answered by that Committee in the form of standardisation now so much taken for granted that it is difficult to believe that any alternative ever existed.

It comes as a surprise to some people to hear that IATA concerns itself with technical matters. The role of ICAO seems to be generally understood; being an organisation of nations and an agency of the U.N., it must obviously concern itself with agreement on both the development and standardisation of many technical aspects of international aviation. But the International Air Transport Association is so active in other fields, that its technical role is sometimes overlooked or misunderstood, and in this paper an attempt will be made to explain this role to those many Controllers who may find themselves in technical discussions with IAT A representatives.

The IAT A which addressed itself to the question posed at the start of this paper existed from 1919 for more than twenty years. The present IATA was formed in 1945, and although it was established out of the remains of the earlier organisation, it was clear from the date of its formation that it would be a far larger organisation with worldwide responsibilities. It was intended from the start that it would wait closely upon ICAO, and for that reason its Head Office has always been maintained in the city in which ICAO has its headquarters. ICAO being an organisation of States, its work is likely to be made difficult at times by political problems; IATA is equally democratic, so that all its members, regardless of size, have an equal vote in policy matters; but being an Association of scheduled airlines, it is less likely than ICAO to be hampered by national differences. As well as having a number of Associate Members, IATA has 91 Member Airlines registered in some 71 countries and these airlines carry between them an overwhelmingly high proportion of the world's air traffic outside Russia and China.

the Financial, Medical, Legal, Traffic Advisory, and Technical Committees. Each of these directs activity within its own sphere of responsibility, and as it is the technical aspects which are being reviewed in this paper, it may be useful to explain that the area of concern of this Committee is laid down as including all technical matters connected with international air transport, particularly the following: i) Operations, including promotion of safety and efficiency of flight; ii) Standardisation of equipment; iii) Communications and radio aids for navigation; iv) Meteorology; v) Airworthiness and maintenance matters; vi) Aerodromes, air routes and ground aids.

The Technical Committee of IATAmeets every six months for about three days, and gives overall direction as to the technical activity of the Association. Much of the detailed work is then carried out by a considerable number of subsidiary Committees. Of these, three of the most important hove worldwide responsibilities, and are responsible directly and through sub-committees for Engineering & Maintenance, Communications and Flight Operations; additionally, there are Panels responsible for various Regions of the world. The Technical Department of IATA is also responsible for organising conferences from time to time, and these have had considerable influence on the development of aviation.

It may be useful at this point to reiterate that IATA is an association of airlines, and it is these airlines which are responsible for making decisions and deciding policy. The Secretariat is headed by the Director General, Mr. K. Hammarskjold, with Department Heads who are responsible for the various departments. In the case of the Technical Department, direction is by Dr. R. R. Show, who heads a small but versatile team in the Montreal head office, with specialists in avionics, flight operations and maintenance and engineering. He is also responsible for the Regional Technical Offices, which are as follows: Geneva covering Europe and Middle East Regions Bangkok covering South East Asia and Pacific Regions Rio covering South America and Caribbean Regions Nairobi covering Africa Region London covering North Atlantic & North American Regions.

When in turn each of these was originally formed, they were one man offices, but as work has increased, there hos been a need for some enlargement. For example Mr. J. L. Gilmore, whose EUM Technical Office is in Geneva, has two assistants, one of whom has special responsibilities in connection with telecommunications.

The Structure of the Association The ultimate authority of IATA is vested in the General Meeting, and an Executive Committee directs the Association's work between these meetings, which are normally held annually. There are then five Standing Committees: -

4

Regional Technical Work The basic framework of IATA's Regional Office activity is routine, and is concerned with the continual development of the ICAO Regional Plan. Although amendments to

this Plan are made in the period between Regional Meetings, it is particularly during the Meetings themselves that changes are developed, and it is, therefore, of interest to review the way in which an IATA Regional Office prepares for such a meeting. The most recent of these was the 5th North Atlantic Regional Air Navigation Meeting (NAT V RAN) and as the writer was responsible for co-ordinating the IATA preparation for it, a short account may be of interest. the NAT V RAN was held from 1-24 April, 1970. The previous NAT RAN had been a "Special" Meeting, and had consequently not considered items such as Aerodromes; this meant that rather more updating work than usual was necessary; in addition to this, the Route Network reviewed by the Meeting was designated by the ICAO Commission to cover a much greater area than the "NAT Region". Preparation by IATA began in May 1969, and from June 1969 onwards, a series of circulars and questionnaires were sent out to the Member Airlines concerned. The replies duly consolidated, a full Preparatory Meeting was held in January 1970, at which the IATA Brief was largely prepared.

After this had been developed further by several small working groups, it was circulated to airlines for comment, and a final series of Delegation Meetings ensured that the eventual Brief met all requirements unanimously agreed.

As IATA is not a State, it cannot send a Delegation to an ICAO Meeting. But although it only has Observer status, many of its Working Papers, especially those tabulating requirements for runway lengths, visual aids, navigation aids, etc. carry a special authority, and the leader of an IATA Delegation is afforded considerable respect. For the NAT RAN, the IAT A leader was Mr. J. Meline of Air France, and his deputy, Mr. P. Powell of Air Canada, whilst they were supported by advisers from numerous other airlines.

It is at a time like this that airline co-operation is really demonstrated, for an IATA spokesman is representing not just his own airline, but the whole Association. This is a point worthy of emphasis, because the outside often seems to find difficulty in understanding how someone who works for an airline can speak on behalf of IAT A. The fact is that when an IATA Brief is being presented, it should make no difference as to whether the spokesman is a member of the Secretariat or an airline employee, and certainly both played a port in this Meeting.

At the conclusion of the NAT V RAN, an IAT A Report on the Meeting was circulated within the Association, and since then, of course, work has proceeded in trying to obtain implementation of the facilities and procedures which were agreed.

Other Regional Work

So much for the basic routine of Regional Activity; however a lot of the work which comes the way of the Technical Representative is more unusual and unexpected and of course it is often that well known country Ruritonia which creates the headaches. All radio communications in Ruritania have failed; can some VHF blind transmission system be organized? The main airport in Ruritania has announced that if any aircraft blocks the runway it will be bulldozed out of the way within ten minutes; can IATA send a delegation to discuss matters? The Space Centre in Ruritania has started launching 200 foot balloons without notification; can IATA make representations? Ruritania is building a new airport; how wide should the runway be? Ruritania is

intending to instal MF Radio Ranges to define a new airway; what does IATA think?

In most cases where questions of this sort arise, IATA arranges consultation between concerned airlines, but in some cases it is possible to give an answer which stems directly from its Manual of Technical Policy. This Manual, built up and amended over the years, gives clear statements on many subjects. For example IATA opposes the use of Radio Ranges and the Manual gives good reasons for this opposition. Many policies have to be modified as time goes by; thus for some years IATA opposed the use of Secondary Rodar unless there was Primary back up available; the reasons for such a policy are obvious. However, it is now becoming accepted that subject to certain conditions, which ensure no diminution of safety, SSR may be used by itself. These conditions inevitably limit the geographic areas where this relaxation of policy applies.

In addition to the Policy Manual, which has 11 sections of which only one deals with ATC, IATA publishes an Air Traffic Services reference document, which offers guidance on international ATS requirements as seen from the viewpoint of civil operations. This also is kept up to date, and is likely to be re-issued in 1971, and of course this also helps to guide the Regional Representative in his work.

A question sometimes posed is this: Why should an administration ask IATA for advice on some subject, when very often it would be ¡quicker simply to ask the national airline? Of course, there are very often cases where the national airline, or a local group, gives a quick and worthwhile answer. But there are several reasons why consultation through IATA may give a better long term answer.

Obviously, the national airline may give a reply with which other airlines do not necessarily agree. But a greater danger is that the individual reply may reflect too much the interests of a particular department; if it is the company Chief Despatcher who gives tne answer, it is liable to reflect the {quite natural and loyal) interests of the Despatch Department, and so forth. An IATA reply, whether developed through correspondence or meetings, is more likely to have been given a balanced construction, and be more in line with worldwide and long term airline policy.

IATA and ATC There are other publications which offer guidance in Regional activity. One of the best known of these is the Airport Terminals Reference Manual, a new edition of which was issued at the beginning of 1971, and which can assist in answering questions on the planning of international Airport Terminals. Although on some occasions a Technical Representative may be able to obtain guidance from one of these publications, at other times he may have to refer to earlier Briefs on the subject, or call a Meeting, or seek airline advice. The range of subjects which may concern him is considerable, and in addition to some of those already mentioned can include the composition of Volmet broadcasts; airfield lighting; aircraft noise restrictions; the accuracy of navigation charts; the coverage of Met. charts and etc, while he may have to represent IATA at airport Consultatives Committees, at meetings planning military exercises and so forth.

But this paper is of course slanted towards IATA work in connection with ATC, which is one of the more interesting and certainly one of the more enjoyable aspects of regional work. In the last two years the writer has made a dozen

5

visits to ATC Centres and has always been made warmly welcome, and has found Centre Chiefs and individual controllers willing to discuss the problems with which they are concerned. Of course this does not make the writer an Air Traffic Controller, for the Controller's job is one which can probably never be fully understood except by someone who has done it. The detailed way in which a Centre operates, or a Controller handles his flight progress strips, is of course no concern of IATA; where IATA's interest lies is in making sure that there is the right communication between the airline, the controller, and the pilot, and that the best attempt possible is made to ensure that safe and ex-

peditious flow of traffic with which we are all concerned.

In achieving this an exchange of views is often desirable.

It is hoped that this short account may promote a better understanding of IATA's work, to the advantage of both Associations. In conclusion a quotation is made from the IATA ATS Reference Document, which seems particularly apt:"Every effort should be made by both operators and ATC authorities towards mutual appreciation of each other's difficulties, since this will promote better co-ordination and efficiency."

***

Letter from Nepal

By Tirey K. Vickers

Tucked into the folds of the Siwalik Hills and the Great Himalayan Range, between India and Tibet, is the remote and isolated mountain kingdom of Nepal. This little country has the greatest range of altitudes of any country in the world. The elevations go from about 100 meters down south, to about 8 700 meters on the peak of Mount Everest up north. As a result, Nepal has a vast range of climates and vegetation, from the tropic jungles of the Terai Plain near the Indian border, to the Arctic-type glaciers of the majestic and eternally snow-clad Himalayas.

No railroads, and few paved roads, penetrate its steeply mountainous terrain. The country has little electric power, few hospitals, and very few communications channels with the outside world.

In many respects, a visit to Nepal is like a visit to the fifteenth century. Over the years, the almost impassable terrain has isolated the country from most of the blessings and curses of modern technology. In Nepal, you can't make a long-distance telephone call, but you can look up at night and see the Milky Way! The chief industry is farming, which is conducted today almost entirely by hand, using the same types of tools that have been employed for a thousand years. Most rural 6

houses have no electricity, no chimneys, and no glass windows. Cooking is done over a small wood or dried cow pattie fire in the middle of the dirt floor. The smoke fills the room and seeps out through the thatch roof. From the outside, this gives you the impression that the whole place is about to go up in smoke. However, the smoke kills the termites, which would otherwise eat up the thatch. Air is admitted to the room through wood grilles in the window openings.

The critical needs of Nepal's 10 million people today are better housing, nutrition, education, and sanitation. The country has almost nothing to export, to get the money to fulfill these needs. On the other hand, Nepal has the world's highest mountains and some of the world's most spectacular scenery. So it's no wonder that the development of tourism has a high priority, as a means of obtaining foreign exchange to meet some of the basic needs. Because of the almost insurmountable barriers to rail and highway construction, the development of air travel has a high priority, as the main method of getting the tourists in, out, and around.

As yet, Nepal has no VOR's, DME's, approach aids, nor airport lights. There is no night flying. The airports open at 7 a.m. and close promptly at 5 p.m. The navaids {a few

Simro hos jumbos but no jets. Contro l Tower in background.

Peak hour ot Simro.

nondirectional beacons) operate on the same schedule.

There are no ARTC centers. Consequently, no IFR flight plans are accepted.

Domestic air services between these locations, and a fe w other towns, a re conducted by three DC-3's of Royal

Nepal Airlines Corporation (RNAC). Th ese a ircraft ca rry w ireless operators who send their position reports and other operational messages via CW! A number of the domestic airports ore only grass strips, which become unusable during the moonsoo n season (July and August).

RNAC also operates a fl eet of Avro 748 40-passenger twin turboprops in daily international service between Kathmandu and three Indian cities: Ca lc utta, New De lhi, and Patna. Foreign air carriers serving Kathmandu include Thai Inte rnatio nal , Pakistan Inte rnational Airlines, and Indian Airlines.

In o couple of years, it is expected that a irport ligh ting wil l be installed at three of Nepal's main a irports, and VHF novoids at fi ve. Meanwhile, if you thrill to the smell of crisp, c lean mountain air, or the sight of owe-inspiring sce ne ry, exotic b irds and blossoms - or if you just wont to g et away from the complexities of the twentieth century for a while - you would en joy this beautiful, friendly little country. But don't try to come during the monsoon seaso n!

Airport termina l bui ld ing ot Moghoulie is not only functional it's practically disposable.

Controller Laleth B. Shaw on duty in Kathmandu Tower

Th e oretically, pilots are expected to remain VFR at all times. Bending the rules is risky business, not only because of the precipitous terrain, but also because of the effect of this terrain on radio navigation. Example : Approaching Pokhara from th e east, the ADF need le swings 60° right and points toward the nearest large mountain (Annapurna), because that's where the strongest (reflected) navaid signal is coming from!

There are no teletypes nor long-l ine interphone circuits.

During working hours, voice radio links are maintained betwee n the Kathmandu communications station ond th e outlying towe rs at Simra, Pokhara, Bhairawa, ond Biratnagor, us ing HF singl e sid e band transceivers.

7

En Route Speed Control Techniques*

By A. J. Kulikowski Team Supervisor, Miami Center

One of the most pressing and demanding problems facing today's radar controller, particularly in the high volume facility, is that of speed adjustment and control.

Simply stated, his job is to organize all air traffic of varying airspeeds, altitudes, performance characteristics, climb/ descent schedules, pilot techniques and preferences-usually deporting from or converging towards the same piece of concrete-into a safe and orderly procession of aircraft.

Inasmuch as safe and efficient separation between aircraft must be maintained, it is necessary to reduce all these variables into one common denominator in the form of groundspeed. Now, to perform a task of this magnitude, the controller needs an intimate knowledge of airspeeds, the factors effecting same, plus a sound speed adjustment technique.

As with any other control procedure, the degree of success with speed adjustment depends on mutual pilot/controller cooperation and understanding. Pilot awareness of some of the controller problems in traffic flow management, the variables involved, the need for in-trail spacing, and the reasons behind speed adjustment requests, is essential to insure success. We would hope for more frequent visits by pilots with the controllers at the radar scopes, affording the opportunity to exchange views as well as to observe ATC operations. On the other hand, controllers can learn about aircraft performance, discuss and a great deal more, while enjoying the hospitality of the jump seat.

The controller must understand airspeed relationships and how they are affected by changing factors. He must know aircraft performance and limitations, and be able to apply this knowledge skillfully in producing the desired results. Let us take a typical flight profile of a turbojet-say a Boeing 727-and analyze the speed range used, in an effort to assess its impact on ATC procedures.

While below 10,000 feet during the climbout, the indicated airspeed is always maintained at or below 250K, since this speed limit is mandatory; but it is above this altitude that we begin to get problems.After passing 10,000, the climb-out airspeed may accelerate to 280K, or as high as 340K IAS. The climb-out airspeed is then flown until reaching Mach .76 or .78; thereafter, a constant Mach number is maintained to the top of the climb.

The climb Mach number will normally be reached somewhere between FL230 and FL250, depending on temperature, with 340K IAS climb attaining this figure somewhat sooner than that of 280K climb. It is interesting to note that, regardless of speed used, the power setting throughout the climb remains constant1 as it is determined by temperature.

The rate of climb wi11 be slighty higher at 280K than at higher forward speeds. . .

Some short-range flights prefer 280K climb while long range departures opt for 340K speed; then, of cour~e, there are different company procedures, individual pilot preferences, and so forth. Our own ATP manual does not P.rovide for speed control of departing traffic, thus preventm~ the controller from issuing speed restrictions. However, if Reprinted from the ATCA Journal with kind permission by its Editor.

8

the pilot concurs, the controller can ask the pilot to climb at a specified indicated airspeed.

One can readily imagine five or six close departures proceeding via the same SID or route, or vectoring room further restricted on both sides by either weather or the busy inbound route from adjacent sectors. It becomes apparent immediately that we must have strict speed control throughout the climb profile, or crowding and difficult situations will develop.

It is rather uncomfortable to watch radar separation disappear on a string of departures when jockeying for speeds begins above 10,000 feet, especially when preceding flights are using a 280K climb schedule, while succeeding aircraft go for broke at 340K. To make this more complicated, all this usually takes place while radar handoff from departure control to the center is being accomplished.

While, at the time of handoff, the minimum 5 mile radar separation exists, it may decrease rapidly by the time initial radio contact is established with the center. As a result, less efficient service to the users is being provided if the requested cruising flight levels-initially preplanned and requested after considering weather, turbulence, cruise economy, etc.-have to be denied because radar spacing is lost in climb and the controller has to resort to vertical separation.

In cruise regime at altitude, speeds are somewhat more stable, but there are still many variables present. Most turbojets cruise in Mach .76 to .86 range. (Mach number is the percentage of the speed of sound at the given altitude.)

For all ~ractical purposes it will vary only slightly at normal cruise speeds at altitudes above approximately FL240.

Here each percentage of the Mach number is equal to about five to six knots of true airspeed. In the more dense atm~sphere below this flight level, the Mach number varies considerably at different altitudes, and is not normally used. Down here, at any given cruising airspeed, Mach numb~r decreases with altitude; and indicated airspeed is used. instead. An easily remembered rule-of-thumb is that an aircraft cruising at Mach .82/.84 at FL31 O will indicate arou~d 310K, with a true airspeed of 480K/500K; each 1 OOO feet increase of altitude will produce five to six knots decrease of IAS, while each 1 OOO feet decrease of altitude will result in five to six knot increase of IAS, assuming a consta~t Mach number is maintained. These figures will vary slightly with changes in weight, pressure, and temperature, but neverthless remain in the ball park.

W~~n it becomes necessary to employ speed adjustment at cruising flight levels en route, to insure specified inter~als between radar targets, meter the flow of traffic, or insure longitudinal separation of oceanic traffic, Mach number r?ther than indicated airspeed should be used.

Here again caution should be exercised because of additional variable factors. . First, winds aloft-especially in the proximity of the 1et stream-may vary as much as 80 to 100 knots within only a thousand feet of altitude. Quite obviously, in these circumstances two aircraft cruising at an identical ~ach number will not necessarily maintain a constant interval, unless both are at the same altitude.

!ew

Second, at the higher flight levels, aircraft operating near the maximum ceiling for a given weight and temperature may not be able to comply with speed adjustments, inasmuch as any appreciable speed change could adversely affect aircraft performance or limitation. In those cases, descent to a lower altitude, vectoring, or even holding may be the only means of producing the desired results.

In terms of speed control, the descent and approach profile is the most critical, as it is imperative that all traffic descending from various altitudes, using different speeds and descent schedules, be neatly fitted into an orderly trail, while maintaining or increasing the specified interval between each aircraft. Normally, most aircraft will gain some speed during descent but not to a significant degree. For example, descent from FL350 at Mach .82/290K IAS cruise, may produce Mach .85 or .86, which is only 15K to 20K faster than the cruising airspeed. This is sometimes referred to as descent at the "barber pole" or just below the maximum/never-exceed airspeed. Some pilots prefer to descend at slightly slower airspeeds or a given number of knots below the "barber pole" airspeed. In all cases, however, the profile is just about reserve to the climb; the Mach number will remain pretty close to the cruise figure in descent through about FL230, then decrease rapidly, while the indicated airspeed will increase at about SK per 1 OOO feet.

One of the most effective means of increasing spacing between aircraft in descent is to require a succeeding aircraft to fly a constant indicated airspeed, say 300K or 280K, obtaining progressively slower airspeeds as the lower altitudes ore reached, while the preceding aircraft maintains normal speed. For example, two aircraft descending from FL350 will initially start with 290K IAS, their normal cruise airspeed. With the second aircraft cleared not to exceed 290K, the speed differential at FL240will be55 knots, since the first aircraft will not be indicating around 345K at normal speed. Of course, speed reduction using lOK increments can also be employed; but the use of Mach number for speed adjustment in descent is impractical.

In order to successfully employ progressive speed reduction during this part of the flight, the aircraft must be descending at a normal rate, somewhere between 2000 to 3000 feet per minute. Delaying descent, or requiring a very low descent rate, will defeat the purpose. Additionally, the winds may be used to a great advantage in planning descent.

There is one more factor that the controller should be aware of, and it is rough air or turbulence penetration speed. Such speed for most turbojets is Mach .78, or 280K IAS, which ever is lower. It should be taken into consideation if reports indicate the presence of turbulence.

From the foregoing discussion, it should be apparent that an effective speed adjustment technique is quite dependent on control of altitude. By having all aircraft at approximately the same altitude, the controller eliminates or at least equalizes most of the variables, so that all aircraft ore affected to the some degree. Having achieved this goal, successful application of speed adjustment becomes easy, and distance between aircraft may be increased or decreased as necessary. The controller must insure that the execution of any clearance is completely within the normal range of aircraft performance.

At this point it may appear that with respect to speed adjustment and control, the controller is becoming rather involved in "flying" the airplane. Not exactly. A more

accurate viewpoint is that, while intimate knowledge of aircraft performance is necessary, the controller is more actively involved in achieving a high degree of pilot cooperation to produce a more efficient flow of air traffic.

In conclusion, here are some recommendations offered in hopes of improving and standardizing the use of speed adjustment in today's en route ATC environment: First, develop agency-wide training-theoretical in the study of airspeeds, variable factors, and aircraft performance; and practical, in the application of speed adjustment and control. This techniques should be developed on radar simulators and perfected in actual on-the-job training. While on a recent visit to the Academy, I had the opportunity to observe radar simulator training in speed adjustment and in-trail spacing developed and taught by Oklahoma City instructors. This excellent training is without a doubt invaluable to the new trainees. It should be further expanded, standardized, and made available to all radar field facilities.

Second, develop a uniform range of airspeeds to be used by all turbojets transitioning to and from en route altitudes via the published STARs and SIDs; these indicated airspeeds to be mandatory, published as a part of procedure, and adhered to unless otherwise authorized by the controller. These speeds should be in the vicinity of 300K IAS/.78 Mach in climb and Mach .80/340K IAS in descent. In reality, then we would have climb/descent corridors with speeds regulated by the procedure, as well as occasionally adjusted by the controller, so as to maintain necessary spacing and an orderly flow of traffic. With sequencing and metering of traffic established before entering the climb/descent corridor, smooth flow would be achieved, pilot/controller workload reduced, and delays (if any) absorbed on either end of the "tube." We have speed limits below 10,000 feet, within the terminal and airport traffic patterns, on the highways and waterways, but why not in the narrow transition corridors where a heavy volume of traffic is funneled in and out of terminal areas?

Third, revise the ATP manual to allow en route controllers to use speed adjustments for departing traffic. These speeds should be within 280K/340K IAS range until reaching Mach .76/.78 or so.

Fourth, incorporate into the ATP manual an appropriate procedure for the use of Mach number, in the application of speed control, to insure longitudinal separation for en route aircraft at cruising altitudes above FL240. At the present time there is a requirement in certain oceanic areas to provide ATC with cruising Mach numbers in addition to true airspeed, but the manual is silent as to the method of application.

Looking into the future, in an attempt to visualize the ATC system of tomorrow, we should like to see the development of airborne station-keeping equipment, perhaps as an added feature of a collision avoidance system, capable of assisting the controller in maintaining constant separation. Such hardware would indeed return the flying of the airplane back to the cockpit, where it belongs, and give the controller more time to supervise traffic flow, identify potential problems, state the required separation to the pilot, and watch the pilot execute the necessary adjustments. This would result in a truly cooperative system evolving from today's passive involvement, to tomorrow's active participation of the pilot in maintaining separation, and with the controller assuming the broader responsibility of insuring the safe and controlled flow of traffic.

9

Air Vision Industries, Inc. IFATCA's Youngest Corporation Member

·~H11J

" Gooneybird" aircraft around Germany and sim ulate IFR e mergencies, to test the alertness and skill of Novice Controllers. One of his favourites was a sudden " pop-up" near a busy holding stack during marginal weather conditions with, allegedly, 20 minutes fuel re maining and "u ncertain of position". But the craftiness of the Controllers soon took the sting out of Ortenburgers sim ulation s. The mom e nt he departed, his tail number and estimated positions were flashed from Controller to Controller in every fac il ity in Germany, and they soo n hod ready so lutions to counter-act the so-called emergencies he cou ld dream up.

\

Ortenburger was also known for a rather spectacular " controller ass ist" in the Munich Centre. On the inaugural flight af a now well established a irline from some place south of the Mediterranean lo Munich, in 1952, the aircraft arrived over the Munich range in rather marginal weather conditions. It executed numerous missed approaches, b ecause the Captain's approach plate foiled to indicate that a 30° turn to the left was required when inbound and after passing the low con e. Soon this e rror and the Captain's severe difficulty with the English language had the aircraft missing its' eight approach with "truly" 20 minutes of fuel remaining . In desperation, Ortenburger ran down seve n flights of stairs, fired-up the "Goo neybird", and fl ew a formation radio range let-down with th e inauguration flight.

When over the low cone for the 9th and lost time, a turn into the other aircraft forced the required 30° turn to lineup with the runway. Still in formation, the air carrier landed on the runway and Ortenburger landed on the grass strip parallel to the concrete runway .

_I

DI

Ai r Vision Ind ustries President Not Eyck . in the fore g round (right) . en. Mobile towe r mock-up

It ce rtainly was a well-tim ed surprise · w h en, a t th e Final Plenary Meeting of the " IFATCA 70" Montreal Conference, Ai~ Vision Industries' President Nat Eycken on be_ho~f of his comp~ny applied for Corporat ion Membership in the Federat1~n. The overwhelming acclamation of the Delega tes manifested the unanimous acceptance of this appl ica tion . . Al.though Ai r Vision Industries is a young name in the av1ot1 ~n sphere, the staff of this dynamic company are dyed in th e wool e xperts with long years' experience.

A.V.I. key personnel orig inate from the Control Tower Manufacturing Division of Canadair Ltd. which, before reorgani zing and concentrati ng their production activities, manufacture d multitudes of control towers fo r airfields throughout Canada, the United States and the World.

First hand operational input to A.V.I. is provided by a man wh o is well known to many Air Tra ffic Controllers, particularly in Western Europe and Germany: Colonel W. R. (Bill) Ortenburger, better known to some of our readers a s " the Errol Flynn of the Air Force". W . R. Ortenburger, one of the founders of post-war Air Traffic Control in the Fede ral Republic of Germany, joined Air Vision Industries Inc. in 1969 as a partner.

As a Captain in the U.S. Air Force, Bill Ortenburger was the Chief Con troller of the Munich Air Traffic Control Center a t Munchen-Riem a irport. Thi s ATS fac ility provided the first post-war OJT to German Co ntrollers, and it was a lso th e first unit transfe rre d for full G e rman operation and respon sibili ty to the F. R.G . Civil Av ia t ion Authorities.

On hi s departu re from Germany, Mr. Ortenburger relinquished hi s Chief Controlle r duties to Mr. Hans Kol le, w ho is stil l in charge of th e Munich Ce nter.

Many of the "Old Time" German Controllers may sti ll reca ll one o f O rte nbu rgers unique field training activ ities.

Freque ntly he wo uld pilot o ne of the Air Force C-47 10

W. R. Orte nburge r recently retired from the U.S. Air Force as a Colonel and a s Chief of Air Traffic Control for H.Q. USAF at the Pentagon. As a partner in A.V.I., Col. Ortenburger continues over 20 years of service to the Air Traffic Control profession. . Ai~ Vision Industri es' President Nat Eycken, when being 1nterv1ewed about the companies activities gave us the following telegram-style rundown: _ ' 1. Prefabricated Air Traffic Control Towers, made to U.S. FAA design criteria, lo satisfy a wide range of requi reme nts in any global e nvironm ent - 450sq.ft., Towers, which can ~ccomodale up lo 14 Controllers; - 350sq.ft. Tewers for 8 lo l O Conlrol lers; - 250sq.ft. TOwers for 6 lo 8 Conlrol lers · - l 50sq.ft. Towers for 2 to 3 Controllers'.

Th ese Towers are desig ned for rapid installation, wi th no field welding requ ired on site. Th ey are adoptable to quick disassembly and movement to another location.

Const ruction is o il aluminium w ith double g la zing.

2. Mobile Towers for temporary bare base operatio n.

They are transportable in C-130 type a irc raft and readily transferable to truck-bed for surface transportation.

This type of Tower is self-conta ined, wi th built-in power supply, transceivers, MET equipme nt, a ir conditioning, etc.

3. Complete turn-key Tower packages, including installation, complete consoles and turrets, with all pre-assembled electronics and radar equipment. All wiring and harnesses ore pre-fabricated, climatic equipment for any environment is provided, antennas installed and connected, and if the customer so desires, the entire facility con be flight commissioned by U.S. FAA trained Flight Inspectors.

4. Airport terminal finger and apron control cobs.

5. Weather-proof, oil aluminium, stressed and insulated shelters for all types of novoids, such as TACAN, VOR, DME, VORTAC. These shelters can be produced for

permanent or transportable installations, complete with climatic controls and equipment, as well as built-in power supply, if so required.

6. Consulting and engineering services for special control tower or shelter requirements, and electronic systems and equipment for tower installations.

The Editor of this journal who, in the late Fifties, hod the pleasure of organising with Col. Ortenburger a TACAN demonstration for oil Germon Controllers, extends his best wishes to Air Vision Industries' President Nat Eycken and to Col. Ortenburger, wishing them every succes in their new venture, and welcoming them as the youngest IFATCA Corporation Member.

EH

*** Training the Controllers of the Future

By J. D. Thomas lst Vice President IFATCA

In all aspects of life today the search is for ideas. Ideas to improve and make more effective existing practices. Air Traffle Control is no exception, in every facet from selection and recruiting through training to operational practices and environmental conditions, people ore seeking ideas. These ideas involve many different problems including how to select the recruits most likely to become successful air traffic controllers, how best to introduce automation; how to reduce the working strain on the individual air traffic controller; how if it is possible, to increase his effective working life. This idea seeking progress must be encouraged and each air traffic controller hos a responsibility to make some contribution to the process so that a synoptic view of air traffic control may be formed. Such a view, based upon the ideas, conceptions and opinions of many indivuduols with widely differing experience, seems to be a most attractive proposition which can do nothing but good. And what better forum to air these views than "The Controller". As a start this paper based on actual experiences concerning the training of air traffic control cadets in Rhodesia, is presented.

Air traffic control cadet schemes are becoming more and more commonplace as the demands for ATC staff steadily increase. Here in Rhodesia the first cadet course was started in February 1968. Before embarking upon the scheme a considerable amount of thought was devoted to; working at the scheme as a whole; studying objectives and deciding how best to attain them; and how best to measure achievement. Although this was a time consuming exercise it was well worthwhile, in fact, it is an essential pre-requisite to any course. This paper will confine itself to the scheme as a whole.

The allied question of where does training finish also provoked much discussion. Having disposed of answers such as "when he is qualified" some reading research was conducted which led to the conclusion that training never finishes, it is a lifelong process. It was discovered that this was not a new thought as a Greek philosopher, Epictetus, had this to soy in about 100 BC. "Education in the deespest sense is continuous and life long. In essence it is unfinishable." (1).

Where does training start and finish?

Planning the training programme

In looking at the whole scheme the first question to be answered was where does training start and where does it finish. Now at first sight there would seem to be no difficulty in answering this question, but this was not the case. It was quickly realised that this is a most complex question. It was reasoned that training itself could be considered a part of

In planning the training programme it was necessary to consider the factual knowledge to be taught, the aviation experience required on the ground and the aviation experience required in the air. The detailed programme for each of these aspects will vary from place to place therefore only the general guide lines used will be mentioned.

the selection process as during the training period each cadet would be virtually under continuous assessment and unsatisfactory performance in any phase could lead to his dismissal. It was concluded, therefore, that training must start with selection, in fact, it was suggested that selection is the most important part of training. If people are selected who are unlikely to complete the course successfully, the entire training effort hos been wasted. To ensure this did not happen the ATC instructional staff were asked to investigate up to date selection methods and make appropriate recommendations.

Today there is a growing awareness of the importance of this lifelong continuous process, due largely to the rapid social and technological changes. It is our belief that such changes ore more evident in ATC than in many other walks of life and great emphasis was placed, therefore, upon the increasing importance of regular refresher and continuity training.

Having decided that training started with selection and it never finished the next problem to be resolved was, how to programme the training, and how long would it take to complete the programme.

11

It was considered to be a waste of time to treat theory and practice as separate entities. Under such a system much of the theory would be wasted as the cadet would have no idea how it fitted into the whole. The following is an outline of the training considered to be most suitable, in chronological order: 1. An induction period of training.

2. A course in ground subjects associated with pilot training, especially navigation, meteorology, radiocommunication, navigation aids, aircraft instruments, principles of flight and aviation medicine.

This course would be made up of formal lectures, air experience (familiarization and as navigator) approximately 30 hours for each cadet and simulator experience (radar simulators and aircraft simulators).

3. An air traffic control assistant's course specially constructed to give the cadet an insight into the ATC function itself, as well as fit him to carry out the ATC Assistant's duties. The course consisted of formal lectures, discussion sessions and simulated exercises.

4. The next year would be spent performing ATC Assistant duties at each of four different airfields, including one military.

S. Another period of air experience, again 30 hours per student, as navigator. This would be followed by a number of route familiarisation flights on scheduled aircraft for flight deck and route familiarisation. These route familiarisations would become a regular part of the cadet's ATC career.

6. The cadet would now be fitted in both the theory and experience spheres to tackle a primary air traffic control course. This course would be devoted to aero-

Examination Time Our reader M. H. Germans hos provided us with this topical contribution to the subject "Controller Training".

12

7.

8.

9.

10.

drome, approach and area control, FIC and AIS work.

This part of the training would consist of formal lectures, discussion groups and simulated exercises.

At the same time each cadet would receive instruction in practical meteorology, how to read the weather charts, and how to make actual weather observations.

The cadet would now have the opportunity to put all his newly learnt expertise into practice in the operational environment, as he would carry out his 'in the field training' for validation.

This would be followed by a period of actual experience in the field carrying out the duties of a procedural controller.

A radar theory course, followed by a surveillance radar simulator course.

A period of 'on the job' training for validation as a surveillance radar controller.

Following a programme based on this schedule the results obtained have been most encouraging. From school to a controller validated in aerodrome approach and area control in less than three years indicates that the programme is a reasonable one. That is not to say there are no areas for improvement. There most certainly will be, but each course completed will provide additional information which will enable us to improve the programme.

Biblography

(1 ). Epictetus.

"This discourses and mannual" translated by P. E. Matheson.

Clarendon Press. Oxford 1916.

AIR TRAFFIC CONTROL SYSTEMS - DEFENCE SYSTEMS - COMMAND AND CONTROL SYSTEMS Selenia's digital display systems cover a wide field of applications ranging from Air Defence (NADGE) to Air Traffic Control (ATCAS). As well as displays Selenia produces computers, primary and secondary radar extractors, simulators and digital interface equipment both for ground and shipborne installation.

selenia digital l)isplay SysleDIS ~NE~~~~~IE

ELETTRONICHE;.

ASSOCIATE SpA SYSTEMS DIVISION, ROME·ITALY

•

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13

Small Data Handling Systems for Air Traffic Control* Many words have been written and spoken at conferences such as this, about the application of the computer to air traffic control. These have been of direct interest to a minority of you and of academic interest to the remainder.

As dissertations, they have educated us all about the tasks which the computer can carry out and the ways in which controllers in very busy areas can have their workload lightened. The one factor which has been common to all the systems has been their expensiveness, which has limited their application. The time has come to re-appraise the approach to system design and to consider the needs of those authorities whose budgets are small and whose air traffic control problems are, for the time being, limited.

Many of these authorities are now installing or updating primary radar equipment but would welcome the opportunity to take advantage of the secondary radar and data handling facilities providing that this can be achieved economically.

The history of the development of the air traffic control services is one of piecemeal implementation, 'ad hoe' improvision and reliance upon the adaptability of the human controller in maintaining adequate levels of safety, order and expedition. In those areas where such policies, or lack thereof, have periodically brought the system to the bri~k of breakdown, public and airline outcry and economic pressures have resulted in the introduction of new equipment and procedures. These have usually solved the problems current at the time of their specification but hove been rendered obsolescent by the growth of air traffic by the time of their implementation. In many cases the improvements have been so limited in conception and in application 1hat further expansion, when not impossible, has been extremely expensive in terms of equipment. re~un­ doncy, commissioning time and procedur~l reor~onasat10~.

The blame for this does not lie entirely with the air traffic control authorities. A major part must be borne by the industry responsible for providing the. tools t~~t controllers need. It is an unfortunate fact that, m the civil field, budgets are limited and experience has been expensive.

This experience must now be used to ensure that, for those authorities whose needs are only just becoming pressing, a viable system philosophy, tro~slatable i.nto economical hardware, is available. The twm foundation ston.e_s upon which this philosophy must be built are adaptab1l1ty and reliability.

The adaptability of a system is a measure of the assurance which con be given to a customer that future needs in terms of the number of operating positions and facilities available con be met, and changes in procedures and methods of operation can be made withou~ red~ndancy of equipment and with the minimum of disruption to the service.

Upon system reliability will depe~d th~ safety.of hui:nan life but it is a fact that equipment will foal. Cons1derohons of reliability must take into account the random notu~e of such failures and provide assurances that under no likely circumstances will service be lost. Two approaches to the Paper presented to the 1971 IFATCA Annual Conference, Athens

14

By T. E. Foster Plessey Electronics Group

problem, not mutally exclusive, are possible. The most straight-forward is to duplicate items of hardware and provide facilities for switching rapidly to standby operation, either manually or automatically. More difficult to design, but more economical to implement, is the concept of failsoft, whereby no matter where a failure occurs, the system continues operating with reduced facilities. As an integral part of the definition of the operational requirement the priority of the facilities must be clearly established and an acceptable minimum defined for any level of system development.

The cost advantages of the fail-soft approach are obvious and must be considered very important in that, under normal working conditions, all the equipment installed is contributing to the system function. The effectiveness of raising the system cost with no return except in terms of reliability must be very carefully judged.

How then can these assurances be given? What system design philosophy can be adopted which will permit customer requirements at all levels of sophistication to be met without levying development costs on each? The most flexible approach is to design a system which meets the most advanced requirement in such a way that it is composed of independent but inter-acting components. These components can be installed one at a time to build up from the very simplest to the most complex system. In a nutshell, design from the top, implement from the bottom.

This philosophy gives rise to four major areas of study, namely, the absolute maximum worthwhile facilities; the minimum practicable facilities; the order of priority of the facilities; the way in which the more complex installations can be made to fail-soft.

The first of these areas is the most difficult and the most open to debate. Technology is currently advancing so swiftly that it is unwise to forecast the state of the art as long ahead as a decade. . It could well be therefore, that commitment to a long li~e of development could prove expensive. Certain techniques, however, in an advanced stage of implementation or develo~ment, such as area navigation, phased array radar aerials, super beacons, satellite surveillance, air/ ground/air data links, give an indication of the route to the system of the future. The final objective, though not in the working lifetime of anyone present, must be to remove the h~man being, controller and pilot, from the loop and to give them the responsibility for monitoring a completely automatic system. In the meantime, however, a practical limit must be established which still allows for the eventual integration of new data and new data sources. A system providing full flight plan processing with radar/flight plan correlation and conflict prediction facilities gives a reasonable aiming point and will be discussed in more detail later.

The determination of the minimum worthwhile facilities to be provided assumes that adequate radio/telephony coverage and primary radar coverage with a raw data analogue presentation are available and do not form part of the system under consideration. Secondary radar is

logically the next requirement, but the simplest possible method of presentation is not necessarily the most economical in either the short or long term. The realisation of the full potential of secondary radar can begin only with the processing of the data to display on the plan position indicator a label associated with each aircraft plot. This label must contain a minimum of two elements giving aircraft identity and flight level (or altitude). Experience at the London Air Traffic Control Centre has shown that the facility for filtering aircraft replies and limiting the data displayed to that pertinent to any particular controller is not a basic essential even in an environment of medium density traffic. The ability to off-set and expand the display provides an effective and very economical method of selecting data for presentation. The problems of label overlap and display clutter can be overcome to a very large extent by the use of the larger displays now available with 22in and even 24in useful surface diameter. Experience is also showing that these are best used in the vertical mode in preference to their use as horizontal conference displays.

The minimal system to be considered is therefore one in which secondary radar data is processed in a plot extractor, correlated at a central input position with aircraft callsign, be it registration or flight number, and arranged for total display.

Once a decision has been reached on the maximal and minimal levels for implementation, the relative priorities for the facilities are fairly simple to determine. Some can be categorised as interdependent and therefore requiring implementation in groups, others require additional items of hardware which then make possible further extensions, and so when the complete list is examined it falls logically into order.

A principle important to the overall system concept can be established from the very beginning by considering the first facility to be added to the basic system. Since this provided for the automatic display of a label associated with every aircraft plot, the next requirement is for some means of suppressing the labels associated with selected plots. For reasons of speed, simplicity and economy this should be some form of designation device such as a rolling ball or a light pen. Note the principle that the controller has not selected data for display, but that display is automatic and suppression is by choice. As the system expands and becomes more sophisticated, this principle will extend so that the processor will perform a process of selection of data for each controller who will have facilities for modifying the resultant display. It is essential that the controller workload be kept to an absolute minimum and that he devotes as much time as possible to absorbing relevant information and as little as possible selecting it or locating it on a display cluttered with data of no immediate interest.

The final area for study before philosophy makes way for engineering is the requirement for fail-soft capability with minimal equipment redundancy. The most satisfactory approach is to divide the hardware of the 'total system' into a number of discrete 'packages' as near to identical with each other as possible. Each of these 'packages' performs its own functions in the overall operation, but by virtue of its similarities can take over those of an unserviceable 'package' if they are of a higher priority. With current technology, the best method of achieving this mode of operation is to use general purpose computers and software programs. For the performance of some of the higher system functions some form of backing store is required

for such information as flight plans of scheduled movements, route structures and aircraft performance. This backing store can thus also contain programs required to reconfigure the tasks of any one processor to ensure the continuity of service in the event of a failure in another processor with higher priority tasks.

Thus we see the concept of software modularity, not only for reasons of system expansibility, but also to ensure fail-soft reliability. Modular software will be discussed in more detail later but it is important to realise that its success, and that of the whole system philosophy, depends upon the design of a comprehensive operating program and the definition of a flexible interface with the individual modules.

Having established a philosophy and a set of principles on which to work, it now becomes necessary for the hard facts of engineering and economics to intrude. The actual requirements of, and for, air traffic control and the tasks involved in meeting them must be analysed. Of these tasks, those susceptible to automation now, and those most likely to become so must be examined for priority and interrelationship. The cost of each step forward must be examined and related to the effectiveness of the improvement.

Industry must bear in mind that hard-headed Treasury officials require more convincing than over-worked controllers.

So how does all this translate into a proposition which can be made to on air traffic control authority? What is the maximum facility system and how is it divided into stages to provide foil-soft capability? What level of flexibility and expansibility can be built into the minimum systems?

Earlier, the point was made that changing technology mode difficult the choice of an upper limit for current system thinking. This does not, however, present as great a problem as might at first be feared. In fact, most of the changes will be in the form of the hardware and its packaging. Other changes will take place in the source, renewal rate and presentation of data rather than in the data itself.

The actual information to be handled and the decisions to be made will remain unchanged in principle for many years. Incoming information will take the form of intention (flight plans), and achievement (dynamic, three dimensional positional information associated with an identity). The application to this information of procedures and experience will result in clearances and executive instructions to ensure a safe, orderly and expeditious flow of air traffic.

Since we have already postulated the use of software controlled processors to provide reconfiguration capability then future advances will give rise to format and interface problems rather than conceptual problems. The very flexibility of general purpose computers, if necessary, one can be provided for the sole purpose of standardising formats, makes them very adaptable to this sort of modification.

The first diagram shows a typical system towards which a forward looking authority can plan its development keeping pace with its traffic. The tasks to be performed are divided between three identical small but powerful processors, two of which are provided with random access backing store. The prime function of these is to hold data on scheduled flight plans, aircraft performance, area route structures and so on. In addition each holds the programs for the other processors so that, in the event of a failure the system can be reconfigured to carry on the high priority tasks.

15

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When a flight plan is received, or becomes active, it is of aircraft height at a point a known distance ahead on analysed in terms of aircraft type, destination and rei!s !rack. Su~h additional d~ta will be displayed only for a quested route and flight level. Estimates are calculated l1m1ted period before being automatically suppressed. from performance, route mileages and wind data. Wind Groundspeed presentation is also available in the form of data can either be stored and updated by meteorological a velocity vector associated with the plot symbol. office input or derived continuously in a heuristic process The position o~ the labels relative to the plot symbol is based on previous comparisons of aircraft ground speed normally automatically controlled to prevent ov I · . "bi h er appmg. and airspeed. Information is presented to the controller It 1s poss1 e, .owever,. as a matter of controller pre ference either printed out as flight progress strips or, as is more to take over this function manually. likely with advanced systems, on an electronic tabular It will b~ noted that the number of control positions in display. The planning controller's clearance based on the the system IS not defined. It is expected that this wm mnge estimates is checked by the system for possible conflicts from three to fifteen, thus covering a wide spect f and these are indicated to him, whereupon he has the . .h h rum o requirements wit out t e need for changes in th d t choice of re-clearing or leaving the problem for solution · system. e a a d .1s t ri'b ut1on by the radar or executive controller. t The next diagram shows the way in which th It will be of advantage in a system of this nature when · d e sys em 1s re uced by the removal of one of the processors d · some International agreement is reached on o method of anc1·11 ary hard ware. Th'1s reduces in the main the I on I itsf allocating a unique secondary radar identity to an aircraft . ht p Ion processing . fl 19 ova1·1 a b le. No calculations eve f o· at the time its flight plan is field. Under these circumstances, . f d . o t I ma es or corre ahon o ra ar with flight plan dat · est1as soon as the aircraft enters the coverage of the secondary formed.

Scheduled flight plans are held in th obis k~erradar it will be recognised and correlation of radar data e ac mg h and others entered by keyb d h store, owever, with flight plan data can be started automatically. If such . oar as t ey become active.

Thus planning data can be d" I d a method of code allocation is not in force, then it will fall 1sp aye an d . .

1f updating becomes necessary this can b · d to the controller to instruct the aircraft to change code on . e carrie out manually, either by keyboard entry or on th e prm . te d fl'19 h t first contact, and system recognition will then follow. . . progress stri~s. At this stage a viable choice still exists, for As soon as this recognition is accomplished comparisons pion data display, between the flight prog ress st rip · an d are made between intention and achievement and updates . the tabular display. If an electronic di"spla y ·is pre ferre d 1t · on the plan estimates calculated. Changes are displayed on . can either be a separate cathode ray tub 't b · the electronic data display to the controllers concerned but . . e uni or e written .a.s a _m1~rotabular display occupying part of the Ian without the requirement for controller intervention. pos1t1on indicator. p Each controller is provided with a plot designation deAutomatic tracking and track initiat'ion , groun d spee d vice, probably a rolling ball, and an alphanumeric and . an d. •vertical speed calculation and auto ma t'1c han d o ff functional keyboard. The use of these devices is kept to an • • fac1 11t1es are sh 11 available in the system. absolute minimum, with the system designed to perform The third . block . .m automatically as many of the routine tasks of liaison and . . diagram shows a fu rth er re d uchon system .sop h1shcat1on to simple second cry ra d or d'1sp ay data selection as practicable. These include routine hand1 offs. At procedurally defined points in the route structure, processing. S.S.R. code/collsign correlation is effected by aircraft are indicated to receiving controllers by, for exmeans of data enter~d at the computer control typewriter. ample, causing the plot symbol to flash. Hondoff is acF~r the c~ntrollers it produces a synthetic labelled pion cepted by designating the plot and pressing a single funcdisplay with n? automatic display allocation. All secondary tion key. rada~ plots will be labelled with flight level and identity, calls1gn or code. These labels may be s uppresse d an d , o f Additional data can be added to the aircraft label by course, recalled by means of a designation device. means of designation and the use of a function key. The most commonly used of these will be ground speed and The process c~n b~ taken one stage further by the revertical speed, the latter being expressed in feet per ground moval of th7 des1gnat1on device, taking away the facility mile. This presentation is chosen to facilitate the estimation for suppressing labels.

16

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Having arrived by this process at a truly minimal system it can readily be seen that the reverse procedure can be followed. Upgrading and expansion is quite literally achieved by the addition of hardware and the input of well tried program tapes. An air traffic control authority can now proceed with the definition and purchase of equipment with the dual assurance that the system is truly expansible to meet future needs at a cost which is known and for which advance budgeting becomes realistic.

In what has necessarily been a fairly brief outline of an approach to the problems of small system design, no mention has been made of the actual display system to be used, and very little of the way in which primary radar data is to be incorporated. These subjects are related and decisions must be the result of discussions with individual operating authorities. It is, however, worth mentioning a few of the possibilities in relation to currently available equipment.

The prime requirement for the display system is for sufficient writing speed and video input facilities to permit the simultaneous display of row analogue and synthetic digital data. In the more advanced systems this may be modified to a totally synthetic presentation. Opinions vary among working controllers on the relative merits of bright and dark displays. Everybody wants better conditions in which to work, but you hove all experienced the difference in extraneous noise levels between on aerodrome control cob and on approach control radar room.

However, there are currently two methods of achieving bright display, namely a fully synthetic presentation with a high refresh rate and scan conversion or derivatives of it such as Digitrace.

The introduction of two phosphor displays is on advance which gives even more flexibility to display presentation.

Used as dark displays, they enable persistence to be chosen, for example, so that synthetic data may be written once per aerial revolution with minimum smear problems and no loss of analogue data. The two phosphors can be of different colours, so that in the bright display mode, data can be categorised for easier assimilation.

The use of horizontal, conference type displays is not, in general proving popular with controllers and tends to make the operational layout of the control room inflexible.

The ergonomics associated with the arrangement of communications and radar controls, auxiliary displays and flight progress strips have never been satisfactorily solved.

The large displays developed for this purpose, however, hove advantages when installed conventionally with near vertical tube faces. Alpha-numeric data con be presented of readable size which, relative to the display area is small and giving minimum clutter problems. This is particularly the case if a port of the plan position indicator is set aside for the display of tabular pion data. Thus the choice of display size now covers the range from 12 inches diameter, through 16 inches to 22 and even 24 inches.

The principle criteria determining the way in which primary radar data ore used ore the number and location of the radar heads, and economics. If a local radar only is being used, then in the initial stages of implementation it is probably best displayed in row form. When the source is remote from the control centre then the relative merits of brood bond or narrow band transmission and the cost of plot extraction will at first be more decisive than the advantages themselves of having available processed primary radar data. It should be borne in mind, however, that full plot extraction plays on important part in the development of the system.

17

In conclusion, I would like to make one further point to emphasise the value of the approach to system development which hos been briefly outlined. Not the least of the problems facing on industry with a vast investment in research and development consists of gaining the confidence of the controllers who are going to operate the system, and of the pilots whose lives ore going to depend upon th e system. Let us gain this confidence step-by-minimal-step and ensure that the facilities curren tly available and the procedures being developed ore exploited to the full to keep safety, order and expedition as meaningful objectives.

Acknowledgements The author wishes to thank the Directors of the Plessey Company for permission to publish this paper.

*** Frankfurt Airport Company opens Data Processing Center It could scarce ly go any faster: In September 1970, construction work for the data processing center started at Frankfurt Rhe in-Main Airport. As early as April 1971 close to l 00 System Analyst's, Programmers and Operators moved in. On June 3, 1971 , the data processing cenler has been inaugurated.

Activi ties of the new EDP center not only comprise internal operational and technica l matters, EDP services will also be rendered to thi rd parties, including customs, passenger handling at the counters a nd at th e gates, the compilation of sh ipping documents for aircraft, as well as the facil itation of the shipp in g agencies ' work.

The interna l activities include the information system in the new passenger terminal, the operation of th e baggage conveyor system, th e positioning of aircraft, the sim ulation of technical and other processes in th e fields of opera tion s and engineering ; furthermore, personnel matters (such as the payro ll ), statistics, book-keeping and auditi ng (including the Duty Free Shops, where ow ing to the EDP the passenger can pay in two dozens of currencies).

All tasks wi ll b e perform ed with the a id of AMIS (Airport Managemen t Inform ation System), which is bei~g developed by the Frankfurt Airport Company and which is being introduced on a step by step bas is. Part of AMIS is a lready in opera tion.

Th ese activities required th e construction of a new building specifically design ed for the EDP department of the Frankfurt Airport Company.

The three-floor building is fully aircond iti oned; a failsafe emergency power unit is installed in the basement.

The first floor a ccommodates the computer system and additional space for archives and data evaluation. In th e upper flo or offi ce space for system analysis and programming as we ll as for oth er activities, such as train ing, is provided. Since the system ana lysts and the programming staff work together in project groups they are accomodated in a large space office, to provide for the necessa ry flexibi lity in group activities .

In the EDP center o ne Sieme ns 4004/45 256 KB Duplex unit and four Siemens 4004/S 64 KB data co mmuni cat ions units are insta lled . Th e co mpute r system is interconn ected by mea ns of data exchange stations and swi tchi ng e lement 18

The computer room of the Electronic Doto Processing Centre o f the Fra nkfurt A irport Company.

groups. Linked to the Siemens computer are also Autophon display boards and the AEG process calculators controlling the baggage conveyor system. Complex internal peripheral equipme nt, including magnetic disc and tape memories, punch card readers, card punchers, lope readers, tape punchers, high speed printers, and console teletype machines, as well as th e e::lernal periphol equipment, including input and output devices read ing and counting stations, complete th e system.

FAG

IFALPA NAV SYMPOSIUM

5-7 October 1971 Hotel Intercontinental Frankfurt, Germany

For further details please contact th e Conference organizers

Vereinigung Cockpit e. V. 6000 Frankfurt 75 NEW 2035007

11rH. ANNUAL IFATCA CONFERENCE

DUBLIN IRELAND 24-27 APRIL 1972 -~-

o· c ounc ll Br idge, Dubl in

at · ton tel surhn9 t•on centre The nO st con"en • ' ne"'e Europes LJ

prepare your flight plan

now!

Briefing details from IRISH AIR TRAFFIC CONTROL ASSOCIATION ORGANISING COMMITTEE 11TH. ANNUAL IFATCA CONFERENCE

Air Traffic Serv ices Department of Transport & Power Dublin Airport Ireland Sha nnon A ·1C Ce ntre

Tel. 01-376497

19

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Athens1971 10 Years IFATCA

The 1971 Annual Conference o f the International Federation of Air Traffic Controllers Associations, which was held from second to seventh Moy, 1971, in the extended premises of the Royal O lympic Hotel at Athens, ha s been a milestone in the history of this dynamic Organization.

In 1971 IFATCA looks back to ten years of continuous effort to enhan ce the safety o f air navigation by providing operational input on Air Traffic Control to va rious leve ls of notional and international aviation.

the consolidated views of t he working-l evel A TC staff, wh ich is based on the professiona l experience o f Contro llers from a ll over the World. Such interest, high l ighted by the most valuab le assistance r endered to t he Greek Ai r Traffic Contro llers Association in p reparing th e Athens Co nference by the Greek Government and by O lympic Airways, is also indicative of the recognition of IFA TCA.

Within that decade the Federation hos experienced a tremendous growth. Th e Argentine Air Troffic Controllers' Association, which joined IFATCA as a ful l member at the Athens Conference, has brought the number of M ember Associations up to 33, with on overall individual membership of some 12.000 A TC staff.

IFATCA President Arnold Field, in his Opening Address to the Conference, said : " ... it is fitting that the venue on this occasion should be the very birthplace of cl assical civilisation. A civilisation which hos given to the world some of the greatest philosophers whose words and works still forrn a f undamental basis for modern art and technology. I am certain that I speak for all of the 32 different nationalities which the Federatio n represents, when I say how honoured we a re ta be guests in such delightful surroundings."

Indeed, the Athens Conference was one of the most successful IFATCA meetings ever he ld. More than 350 Delegates and Observers from oil over the World participated in this impressive gathering. With almost one hundred percent of the Member Association being represented, the tru ly world-wide scope of the Federation was readily apparent.

The international status of IFATCA was, however, not only manifested by the number of Member Associations in attendance but equally, or even more so, through the representation at Conference of numerous I nternationo l Aviation Organizations, Notional Aviation Author ities, civi l and military a irspace users, and other related bodies with an interest in international air navigation.

The very active participation in the Conference deli be ra tions by high level Observers from nationa l and international organizations demonstrated the wide interest in

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IFATCA President Arnold Field welcoMing the Delegoles of the Argentine Association as youngest IFATCA Member.

Athens -

view from the Acropolis.

The Greek Minister of Communicotions, Mr. George Vallis, addressing the Conference.

Guests of Honou r ot the O p en ing Ce remo ny.

Fi rst Plenory Meeting. Jn the foregro und the Delegates of the Netherland s Gui ld and of the Netherland Antilles ATCA.

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The exhibition stand al Gustav A. Ring, Oslo.

The Greek Minister of Commun icotions in disc ussio n with R. N. (Bobbie) Harrison.

Bob Shipley exp lo ining to the Minister sp ecific fea tu res of a Cassar Radar Display.

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Recognition as a professional organization that has grown to maturity in a very short period of time. High quality of work produced (on a voluntary basis) by Member Association s, Standing Committees and Officers, and faithful adherance to IFATCA's Constitution hove gained the Federation world-wide reputation. The frequent invitations for IFATCA to participate in ICAO Conferences ore mainly based on this reputation as o responsible, professional body.

The Greek Minister of Communications, Mr. George Vollis, and his staff took particu lar interest in the Conference. After having extended a fri end ly Address of Wecome at the Open ing Ceremony, the Minister attentively participated in the first Pl enary Meeting. Then he officially opened the exhibition of ATC eq uipment that was on display at the foye r of th e Royal Olympic Hotel. During his tour of the exhibition, th e Minister had many detailed questions, and he spent o lon g time in discussion with the representatives of IFATCA Corporation Members at th e individual exhibition stands.

Mr. Athonosios Botsis, Secretary Genera l, Ministry of Communications, and Mr. Kiriakos Ponogopoulo s, Civil Aviation Administrator of Greece, who we re Gue st Speake rs at the Opening Ceremony, assisted the Minister during this function.

Mr. Kiriakos Pana gopoulo s (cent re) with IFATCA Preside nt Arno ld Fi e ld (rig ht) and Hono ra ry Secretary Horst G udda t (le ft).

The exhi bition - one night before the opening of the Conference.

To honour the lOth anniversary of IFATCA, the Greek Mini stry of Communications had issued a specia l franking stamp. This was availabl e on the opening day at the temporary post office that had been establ ished a t the Royal Olympic Hotel.

~OF AIR TRAFFIC CON1.:r ,

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Post o ffi ce ot the Royal Olympic Hotel.

At the Telefunken stand.

H. Loube (second from ri ght) describes ta the Mi ni ster of Communications the various activities of AEG-Telefu nken in the field of A ir Tra ffic Control ond Automa tic Data Processi ng. IFATCA President Arnold Field and G eorge A5!anides, the President of the Greek ATCA, o re listening in .

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Ten years IFATCA and world-wide participation were not the only factors which made the Athens Conference a milestone. For the first time at an Annual Conference did it become necessary to split up into three groups, instead of two, in order to deal with the heavily charged agenda: - Committee A" Administration and Nomination"; - Sub-Committee A "Human and Environmental Factors in Air Traffic Control"; - Committee B "Technical and Professional Matters".

Some of the more important subjects dealt with in Committees and Sub-Committees were:

Recruitment and Training of Air Traffic Controllers Although no definite policy on Controller Recruitment and Training has yet been established by IFATCA, the report of Standing Committee V highlighted some of the problems presently encountered in the training of ATC and suggested a broad approach that could be taken by the Federation. Standing Committee V were quite firm in stating that "Air Traffic Control is a young man's job" and that the effective working life of a Controller was not more than 20 to 25 years.

These c~nsiderations were important factors in making the Committee suggest that the educational entry requirements for ATC trainees should be raised to post-secondary education of a specialised nature. The academically d.isciplined background of such trainees would not only increase the success rate of ATC training, but would also alleviate the exit phase from active control duties. ATC staff with such a background would more readily absorb management and administrative training and would also have a good basic framework on which to build an alternative career.

Standing Committee V was not suggesting that the higher academic education would be an "end all" to cu~­ rent recruitment and training problems or that present Air Traffic Control staff were less qualified. On the contrary, S.C.V. emphasized that nowhere, in any profession, were there more dedicated and conscientious individuals as they are now employed in Air Traffle Control. But the hig~er education would better equip Controllers to cope w~th the rapidly changing ATC environment, provide them with better opportunities for becoming future ATC r:r'anagers, and to give them a chance to favourably competing on the . . job market when leaving the system.

Taking all these points into account, Standing Cor~1t­ tee V had produced a draft program, covering a period of approximately three years of academic, simulator and on-the-job training.

The report was accepted by Conference, but referre~ back to S.C.V. for consideration of the feasibility of individual proposals, and for expansion in regard to ~ career structure additional to the executive ATC function, but within the ATC environment. All Member Associations were requested to actively participate in this project.

Requirements of SSTs regarding Air Traffic Services Based on a report of Standing Committee I, the Conference considered the revised list of operational requirements applicable to SSTs in the field of Air Traffic Control, as established by the ICAO SST Technical Panel.

In this context reference was made to DAAO (U.K. Board of Trade Directorate of Advanced Aircraft Operation) Paper No. 1 "SST Airborne Manoeuvrability and Flight Path".

24

S.C.I. found no basic disagreement with any of the items on the ICAO list, but suggested that some of the proposals might not be capable of world-wide implementation before the Concorde flies in service (excepting the NAT Region) and that the necessary technical resources may well hove to be introduced on a Regional basis.

The Meeting finally charged Standing Committee I with a detailed study of "ICAO Guidance Material for ATS Personnel on the Performance and Operating Characteristics of SSTs during all Flight Phases".

Air/Ground Automatic Data Exchange Already in 1965 IFATCA Standing Committee I had produced a substantial paper on this subject (65.B.27). This paper, which slanted favourably towards Data Link Systems, was considered a good general survey of air/ground/ air communications problems.

Meanwhile the ADIS Panel had been established, however its activities had centered on ground/ground aspects, with only an exchange of view on air/ground problems.

Standing Committee I suggested for IFATCA to re-affirm that the basic communication problems still exist and, bearing in mind the increased use and understanding of SSR since 1965, and the increasing application of computers in Air Traffic Control, that the Federation should concentrate: - on the definition of ATC problems which a data link could solve or alleviate; _ operational characteristics of the data link required.

As a step into that direction and in order to prepare a world-wide survey on controllers' experience with air/ ground automatic data exchange, S.C.I will design and disseminate an appropriate questionnaire to all Member Associations. Upon receipt of the replies, the Committee will evaluate them for the possible establishment of IFATCA policy.

Turbulent Wake Procedures The expected world-wide increases in heavy jet traffic may produce significant problems for Air Traffic Control.

A study on how the dangers of VORTEX generation can be avoided will therefore be on the permanent work program of IFATCA's Standing Committee I. The Conference also concluded that any difficulties encountered by Member Associations in this respect should immediately be reported.

Automation in Air Traffic Control This subject is already on the IFATCA work-program since two years. The 1971 Conference has established the following priority areas, which will be studied immediately: - Compatibility of automated systems; - Controller involvement in detailed analysis and programming; - Controller involvement in subsequent system development and modification.

Radar Monitoring of Aircraft using Reduced Separation Standing Committee I had produced an extensive paper on this subject, which was discussed at length. In the end, it was decided that the paper should be made available to interested international organizations, such as ICAO, and that Section 6 of the paper should be adopted as

IFATCA policy on the concept of radar monitoring of aircraft, navigational accuracy, and reduced horizontal separation. The main contents of Section 6 are related to: - Factors affecting the ability of radar controllers to monitor track-keeping accuracy and the maintenance of separation between pilot-navigated aircraft (Radar Controller workload, aircraft navigational capability, radar equipment a nd display characteristics, weathe r effects).

- Monitoring of pilot-navigated track-keeping accuracy.

- Monitoring of separation between aircraft along closely-spaced, pilot-navigated, parallel tracks.

- Monitoring of reduced longitudinal separatio n between aircraft estab lished at cruising leve l.

- General requirements for radar monitoring.

Th e ent ire paper, as amended, wil l also be used as guidance material, particularly as a basis for IFATCA briefs of presentations to ICAO meetings.

SSR Mode C and Omit Report Procedures Only limited "omit report" procedures are currently in use, i. e. the ommission of certain R/T position reports and forward estima tes, but not the R/T reporting of fl ight level information. Hence th ere is insufficient information and operational experience on this subject. This was considered to be unfortunate in view of the forthcoming 6th EUM/ RAN Meeting of ICAO, and bearing in mind the anticipated increase in radar monitoring workload resulting from th e introduction of the full "omit report" procedure.

Particularly when ope ratin g in the ,. manual " mode of radar monitoring, Controllers may find that they have to o?tain too much information visua lly (by systematic sca nning for detai led information on position and height), whi le their ab ility to obtain information aurally (by R/T reports from aircraft) is too little used.

The report issued on a recent UAS trial in the U.K. (with full omit report procedure) po inted out the d iffi culti es Controllers had in observing from the labe lled display when aircraft w he re climbing or descending or rea che d their cleared level.

A ll Membe r Associations were urged to provide re leva nt information in sufficient time for it to be used by the IFAT CA Observer to the 6th EUM/ RAN Mee ting.

Loss of Licence Insurance Th e difficulties of arranging an international scheme appeared to be so great that it was decided to discontinue effo rts to p roduce such a scheme. The information that has been obtain ed so far w ill be availabl e to Member Associat ions considering a national scheme, on application to the Swiss Association.

Human and Environmental Factors in Air Traffic Control Sub-Committee A had been set up to dea l with this topic, unde r th e able cha irmanship of J. D. Thomas, the new ly elected First Vice Preside nt of the Federation. W o rking age of Controll e rs, shift rostering, rest periods, night duty, medi ca l checks and physical and men tal abi lity of staff for Air Traffle Contro l duties w e re among th e topics discussed in this working group.

How to cope with the Growth IFATCA now has 33 Member Associations, and can truly claim to represent the opinion of Air Traffle Controllers throughout the World. The most important element in making the Athens Conference a milestone in IFATCA history is probably the fact that the continued growth of the Federation taxes to capacity the voluntary effort on which depend most of IFATCA's activities. The step from this voluntary effort to a larger executive work force, which the Federation may have to face in the future is a very big jump. It will involve a considerable increase in financial expenditure. Member Associations and Officers will have to carefu lly consider the implications which involve the further expansion of activities by the Federation.

IFATCA President Arnold Field, in his report to the Final Plenary Meeting, announced that the Board of Officers in order to assist Member Associations in their consideration of this important matter, will prepa re a list of what they consider the objectives of IFATCA should be. The IFATCA Finance Committee will then work out a figure of cost for these objectives, following which a development plan will be proposed of how they could be achi eved.

The Delegates o f the Australian Association, Lowrie Cummings (left) and Ray Soden (right), had travelled o long way to attend the Athens Conference.

Exhibition of ATC Equipment and Technical Presentation Standard features of a ll IFATCA Conferences are the exhibition of ATC eq uipment and the technical presentation or pane l discussion of th e IFATCA Corpo rat ion Members.

At th e Athens Conference, the follow ing presentations were made and met with great interest: - From SATCO to SARP, by Mr. Mila of Hollandse Signaalapparate n; - Data Handling Systems for ATC, by Mr. T. Foster of Plessey Electronics Group ; - Information Pres e ntation in ATC, by Mr. R. N. Harrison of Ferranti Ltd.; - SSR Equipment fo r the Computer Environm e nt,

by Mr. R. Ship ley of Cossor Electronics Ltd.; - GAREX-5, the modern, modular and expanda b le Te lecom System, by Mr. J. Bennett of Gustav A. Ring A/ S; - Improved Navigatio n Capabilities, Quo Yod is?,

by Mr. W . E. J. Groves of the Decca Navigotior Co mpany, Ltd. Supporting the pa pers presented were a nu mber of techni ca l e xhibits, perfectly a rranged in the hall of the Royal Olympic Hote l. They aroused considerable d iscussio n an d interest. Th e Greek Mini ster of Communications, Mr. George Va llis, spent o long time visiting the exh ibitio n and discussing in detail w ith IFATCA Corporation Me mbers the vario us syste ms on display.

25

Old friends of IFATCA. Well-known to oil Conference porticipants since the early days of the Federation: Paul Berger of the ICAO Regiona I Office Paris (right) and George Wal ler (FAA) with Mrs. Waller (left), Mrs. Johansen-Gobel and Wolf Gobel of the German ATCA (centre).

Captain a nd Mrs. Muirhead, IFALPA, al a social function sponsored by the G ree k Airline Pilots' Association.

Capta in Spyres Cho rafos, President of the Greek Airline Pilots' Association is on the right, Mrs. Chorafos on the left side of the p icture.

An album with a photographic record of the Conference activities is offered to the Greek Minister of Communications

by IFATCA President Arnold Fie ld a nd Greek ATCA President George Aslanides, a s a so uven ir of " IFATCA 71". Nick Gono s is co mme nting on the p roceed ings via the Hi-Fi sound syste m of the Club Aste ria.

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Conference Organisation and Social Arrangements Last o n tlie list of factors which made the Athe ns Conference a milestone in IFAT CA hi sto ry, but definitely not th e least, are Conference organisation, warm hospitality, and superb soc ial a rrange ments. Th e Greek Associa tion as a w ho le, and its members individually, aroused the utmost adm irat ion fo r the excell e nt o rga nis a tio n of the Conference, and the amount of work put in to see that it functioned smoothly.

Overwhelming hospita lity was e xtended to Delega tes and Observe rs by vari ou s organizations. These social f unctions provided an exce ll e nt opportunity for meeting w ith officials of th e Aviation Admini stration, airline management staff, civil and military pilots, a nd representatives of national and international a viation o rganizations. Shop talk often continued until midnight, w hi ch was not always favoured by th e lad ies, who had rath e r seen their husbands fo rget about Air Traffic Contro l after the official business session s.

An interes ting ladies' program had been arrang ed by the Greek Associat ion, w ith visi ts to the Acropolis and to Delphi, s ig ht-see ing at Athens, specia l museum tours, and in d ividua l shopping a ssista nce by Greek ladies.

At severa l occasions the Confere nce participants were guests of th e Greek Minister of Communicat ions. The most splendid of these eve nts was a dinner party at th e seaside "Asteria '', which also provided a very pleasant introduction to G reek folklore and to bouzoukia music.

Professor Th eod. Garofolodis, Pres iden t of O lympic Airways, was charmin g host to the IFATCA group for an evening at the Club N ereida in Kalamaki. At this occasion the Conference a tte ndants met w ith ma nage me nt staff of Olympic A irways. O lympic Vice President R. Lo ubry was partic ularly inte reste d in the activities o f th e Federation and had long discussions with IFATCA Officers and Delegates.

Th e final highlight of the Ath ens Conference was a sea cruise among the Saronic isl a nds, at which the Delegates we re the Guests of the Coast Lines o f Greece and the Greek Natio nal Tou rist O rg aniza tio n. Landings were made at Poros and Hydra. Magnificent sunshine, t he beauty of the G reek islands, and the friendly hospi ta lity of the host organizations mad e this excursio n a n event which no participant wi ll ever fo rget.

Th e friendly bonds existing between IFATCA and national and international pi lots ' organizations since the early days of the Federation were aga in manifested at Athens, both in Wo rk ing Sessions as well as during social f un ctions to w hich the pilots had invited t heir fe llow workers on the ground.

Election of IFATCA Officers Th e following Officers were appointed by the 1971 Annua l Conference: J. D. Thom as (Rhodesia), replacing First Vice Presid e nt : J. R. (Dick) Campbell who has been e lected Executive President of t he Canadian Air Traffle Control Association, In c.

Hon o rary Secretary: Horst G uddat (Germany), re-elected.

Wa lte r H. Endlich (Germany), reEditor: e lected.

Location of Annual Conferences 11 th Ann ua l Confe rence 1972 l 2th Ann ua l Confere nce 1973 l 3th Ann ua l Conference 1974 14th Annual Confe rence 1974 -

Du bl in, Ire land, 24/27 Apri l 1972 Iceland Israel (provisiona l) Australia, Austria, Hungary and Rhodesia have issued invi tations.

EH

Conference organisers at a lighter moment. l. to r. El ias Karayannidis, Napoleon Vletsas, George As lanides, Nick Gonos, Po livious Ma th ioudakis, Costas Theodoro polous.

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Letters to the Editor An Open Letter to Mr. Grambart SUBJECT:

Your Article AN APPRAISAL OF ATC AUTOMATION

Dear Mr. Grambart !

I have just read your article AN APPRAISAL OF ATC AUTOMATION and must say that it hits the ATC-Automation-Problem-Nail right on the top. I should like to make a few remarks in general on points of importance, if you allow.

1. Why does nobody want to answer the separation question for synthetic dynamic traffic displays? Is it that they fear to tell the public, airspace capacity could be lost instead of being gained? Everybody seems to be aware of the problems and choses different symbols for radar derived data on the scope, depending in their origin, primary, secondary or combined primary and secondary data received from the antenna. But nobody seems to take the corresponding following and logic steps and either increases the radar separation minima or makes the symbol bigger to make good for the inaccuracies not visible to the controller. Whom does it really help to change a 7 NM wide SSR target into a e.g. 1.5 NM wide synthetic symbol?

It surely doesn't help the pilot or the controller. It's the 'positional truth', as you say, that must be given, if one does not want to increase work for the controller and thereby decrease capacity.

2. I completely agree with your remarks at the end of page 13. A thorough ATC System Analysis has to be done before any other steps are taken to automate an ATCPart.

3. We all know that the less input necessary by the controller the better the automated part of the system will be, but we fear to give too many of such tasks to the computer. Is it for reasons of money, expensive or capacity using additional programmes, or what?

4. People should be assured that much has been gained, if we succeed to ease the memory burden of the controllers, in respect to safety and money spent. The possible increase of airspace/sector/controller/etc. capacity is only a second thought and aim.

5. And to increase capacity one has to organize its basic ATC system according to the traffic flow needs first, i.e. provide for one way routes, allow for an altitude conflict free crossing of air routes, etc. Once this has been achieved, automation can come in and help to solve the information and data presentation and absorption mass problems, make the traffic movement more easy along those tracks, closely spaced, i.e. about 15 NM or so.

6. The operation of flights 5 NM apart in an enroute system, what some people outside ATC, but providing funds for it, apparently do not understand, means the end of any enroute system. It is like driving all automobiles with maximum speed along a high traffic density highway during night time, foggy conditions and lights switched off.

Whereas a wisely chosen separation minimum, taking into account coordination times, speed changes without notification, heading changes, wind effect, etc., reaction time of the controllers and the pilots, could mean everything and possibly be in the area of 15 to 20 NM (with the assistance of automation).

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7. We do not have a 5 NM separation ATC system today, nowhere. And if we approach this value somewhere and sometimes in any ATC system, we are giving the whole problem to the controller, and there is no better computer than he. The type of operation of quite some ATC units is coming close to such a catastrophic situation and we must move away from this, not make it the rule. The controller is a human being, the cheapest part of the ATC computer system, the most valuable part in it and must therefore be treated in the best way possible. I join everybody in saying that all parts of the system must be designed to suit him and the pilot.

8. I recall an IFATCA Conference open forum in Geneva in 1967, where I asked for a quiet picture of the traffic situation for the controller and a representative of the industry asked me, if I wanted them to install a rubber hammer to wake up controllers. I answered that this is exactly what the controllers need, to assist them in the maintenance of identity and the remembrance of problems ahead. Automation will definitely help to regulate the traffic flow, but cannot decrease the amount of traffic and therefore will leave the controller with most of his present problems to be solved by himself.

Very truly yours, Frank W. Fischer

*** The Niirnberg Raid An English historian, Martin Middlebrook, is writing a book about the great air battle which took place on the night of March 30th/31 st, 1944 when the British Royal Air Force Bomber Command raided the German city of Nurnberg. The British lost 95 heavy bombers on this night; most of these were shot down by German night fighters.

Mr. Middlebrook is anxious to obtain personal accounts of this air battle from any of those taking part. In particular he would like to hear from: German night fighter crews, German night fighter controllers, British bomber crews.

Would any reader who can help please write to: Martin Middlebrook, 48 Linden Way, Boston, Lines, England.

••• and~ 24-27 April 1972 11th IFATCA Conference Dublin, Ireland Hotel Burlington

Corporation Members of the International Federation of Air Traffic Controllers' Associations AEG-Telefunken, Ulm/Donau, Germany Air Vision Industries, Inc., Montreal, Canada The Air Transport Association, Washington D. C., U.S.A. Wolfgang Assmann GmbH., Bad Homburg v.d.H. ComJ:?agnie Generale de Telegraphie sans Fil Malakoff, Paris, France Cessor Radar and Electronics Limited, Harlow, England The Decca Navigator Company Limited, London ELLIOTI Brothers (London} Limited Borehamwood, Herts., England FERRANTI Limited Bracknell, Berks., England Glen A. Gilbert & Associates, Washington D. C., U.S.A. IBM World Trade Europe Corporation, Paris, France International Aeradio Limited, Southall, Middlesex, England ITI Europe Corporation, Brussels, Belgium Jeppesen & Co. GmbH, Frankfurt, Germany The Marconi Company Limited Radar Division Chelmsford, Essex, England N.V. Hollandse Signaalapparaten Hengelo, Netherlands N.V. Philips Telecommunicatie lndustrie Hilversum, Holland The Plessey Company Limited Chessington, Surrey, England Selenia - lndustrie Elettroniche Associate S.p.A. Rome, Italy The Solartron Electronic Group, Ltd. Farnborough, Honts., England Texas Instruments Inc., Dallas 22, Texas, USA Whittaker Corporation, North Hollywood, California, USA The International Federation of Air Traffic Controllers' Associations would like to invite all corporations, organizations, and institutions interested in and concerned with the maintenance and promotion of safety in air traffic to join their organization as Corporation Members.

Corporation Members support the aims of the Federation by supplying the Federation with technical information and by means of an annual subscription. The Federation's international journal nThe Controller" is offered as a platform for the discussion of technical and procedural developments in the field of air traffic control.

ground air defence

naval defence

air traffic control

airfield monitoring

S600 SERIES-THE MODULAR SOLUTION FOR ATC The Marconi S600 series, the most advanced range of modular radar equipment in the world, enables custom-built air traffic control systems to be created off-the-shelf without any need for special development.

The total modularity of the S600 series gives complete freedo m in the cho ice o f facili ties provided with in any system.

Furthermore, the system, or any facility within it, can be readily extended whenever the need arises.

Standard sub-systems, built up from basic S600 series elements, have been created to meet specific air t raffic control applications. These uni ts can be brough t together in various co n fi~u rat i ons to pro vide com plete systems that will satisfy, both operationally and techn ically, any individual air traffic control req ui rements.

S600 series standard sub-systems for Air Traffic Control Aerials for 50cm, 23cm and SSR , short, medium o r long range.

Turning gears wit h turning speeds from 5 to 15 rpm, single or dual drives.

Transmitter/receivers fo r 50cm, 23cm and SSR, all crystal controlled or referenced.

Digita l signal processors with wide ra nge of plug-in facil ities.

D igital extractors for primary a nd seconda ry radar.

Radar data processors with mod ular computers.

Flight plan processors with wide expansion capabil ity.

Viewing units for radar or data d isplay in colo ur o r monochrome with pl ug-in dig ital or a na logue mod ules.

Daylight viewi ng displays for approach and airpor t control using di rect-view sto rage tubes.

D igital radar simu lators, completely compati ble with operatio nal eq uipment, for training and opera tio nal forward planni ng.

Marconi Radar Systems Limited C rompton Works, C helmsford, England CMI 3BN and New Par ks, Leicester, England, LE3 1UF A GEC-Marconi Elect ronics Cornp3ny

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5654 - an advanced 23 cm (L) Band Radar The Marcon i S654 is an advanced modular 23 cm (L) Band radar designed to satisfy a ll AT C sur veillance requiremen ts in two sta ndard configu ratio ns. For Approach and Terminal Area Control a high p.r.f, short pulse leng th a nd high aerial turni ng s peed are used with o ne transmitter operating. For en-route surveillance the p.r.f. is lowered , the pulse length increased, the aeria l turning speed reduced and two trans111itters a re used in d ivers ity operatio n.

T he S654 employs a d ual-bea111 aeria l system which com bines overl apping high a nd low cover beams fro111 a single aeria l, the lower beam on ly being used fo r transmissio n and bo th beams fo r recepti on. T he fea ture reduces ground clutter and 'a ngels' o n the radar d isplay while preserving the st rength of a ircraft ret urns.

Very efficient circular polarisers o f new design are fi tted to bot h bea111s fo r further p rotectio n agai nst weather clutter.

T he so lid s ta te S600 series transmitter/ receiver em ploys a n entirely new design of

magnetron in which electrical and mechanica l vibrati on have been reduced to negligible proport io ns to achieve exceptional pulse-to-pulse sta bil ity. In add ition, complete lo ng term stability is achieved by referencing the magnetron freq uency to a crystal. The associated signal processing, which can be analogue o r d igital, is co mpletely modula r offering a wide choice o f fa ci li ties, incl ud ing extremely sta ble double-cancellatio n MT I. The d igita l system incl udes very effi cient 8-bit word signa l quantiza tion fo llowed by phase and quadrature detecti on and two entirely independent MT! cha nnels to eliminate blind phases and to provide fa il soft operatio n. Fully co m patible with the dig ita l signal processing is an advanced pl o t extracto r which provides da ta either direct to a p rocessor or in serial fo rm s uitable fo r tra nsmission over a narrow band lin k.

M arconi Radar Systems Limited Crompton Works, C helmsford, England C M ! 3BN 4/ B

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