IFATCA - The Controller - August 1975

D 21003 F

JOURNAL OF THE INTERNATIONAL FEDERAT ION OF AIR TRAFFIC CONTROLLERS ASSOCIAT IONS

In this Issue:

Effects of SST and General Aviation Traffic on Controller Capacity The Eurocontrol Institute

F RANKFURT AM MA I N

IFATCA '75 Conference Melbourne

AUGUST

19 75

VOLUME 14

N 0

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IFATCA'76 · 26-30APRIL· IFATCA '76 .

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THE CITY OF IFATCA'S XVth ANNIVERSARY CELEBRATION

IFATCA

JOURNAL

OF

AIR

TRAFFIC CONTROL

THE CONTROLLER Frankfurt am Main, August 1975

Volume 14 • No. 3

Publisher: International Federation of Air Traffic Controllers' Associations, P. 0. B. 196, CH-1215 Geneva 15 Airport, Switzerland.

Officers of IFATCA: J-0. Monin, President, 0. H. Jonsson, Vice-President (Technical), R. E. Meyer, VicePresident (Professional), E. Bradshaw, Vice-President (Administration), T. H. Harrison, Executive Secretary, J. Gubelmann, Treasurer.

Editor: G. J. de Boer, P. 0. B. 8071, Edleen, Kempton Park, Tvl., 1625 South Africa, Telephone: 975-3521 Contributing Editor: V. D. Hopkin (Human Factors) Managing Editor: Horst Guddat, D-6368 Bad Vilbel 2, Otto-Bussmann-StraBe 7, (Federal Republic of Germany).

Telephone: (06193) 85299 Publishing Company, Production, Subscription Service and Advertising Sales Office: Verlag W. Kramer & Co., 6 Frankfurt am Main 60, Bornheimer Landwehr 57a, Phone 43 43 25 and 49 21 69, Frankfurter Bank, No. 3-03333-9. Rate Card Nr. 4.

Printed by: W. Kramer & Co., 6 Frankfurt am Main 60, Bornheimer Landwehr 57a (Federal Republic of Germany).

Subscription Rate: OM 6.- per annum for members of IFATCA OM 10.- per annum for non-members (Postage will be charged extra) 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 are welcome as are comments and criticism. No payment can be made for manuscripts submitted for publication in "The Controller". The Editor reserves the rig.ht to ma~e 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 any part of this Journal.

fotos: Archiv. Boeing, Cossor, Eurocontrol, Lufthansa Cover: Horst Guddat Cartoons: Helmut Elsner Advertisers In this Issue: APCAllFATCA 76, (inside cover), Cossor Electronics (page 2), Hollandse Signaalapparaten B. V. (page 4), Ferranti Digital Systems (page 26/27), Qantas Airways (page 37), Selenia Radar {back cover).

j

CONTENTS

The Eurocontrol Institute of Air Navigation Services

5

Value Engineering applied to ATC . • .

13

How Canada tackled its STOL Pro)ect

17

Future Commercial Air Transport Developments

19

Effects of SST and General Aviation Traffic on Controller Capacity

24

Report from the 1975 Conference, Melbourne

33

The Low Drag/Low Power, One Segment Approach

39

Fuel Economy with Linear Holding

41

The Pilot's Point of View .

41

News from the Federation

43

News from Member Associations

44

Airports and their Control Towers

46

News from Corporation Members

48

Accident Investigation Report .

50

Letters from Readers . . . . .

52

In 1984 Cossor SSR will still be watching out for you It has been estimated by the Civil Aviation Authority that air traffic will increase threefold by 1984.

It has been estimated by Cossor Electronics that air travel will be three times safer by 1984.

Why? Because ai rport authorities are increasing ly adopting the almostinfall ible type of air traffic control system pioneered by Cossor, based on Secondary Su rveill ance Radar.

Recent SSR developments by Cossor mean that more ai rcraft informa-

cossor4 2

t ion is now available to air traffic controllers much more quickly and accurately than has been possible to date.

Coss.:ir's first experimental SSR was produced in 1950. Continu ing development has led to the introduction of the SSR 990, a complete air t raffic co ntrol system incorporating advanced data processing and display techniques.

It leads the world in radar technology.

COSSOR ELECTRONICS LI MITED, TH E PINNACLES, HARLOW. ESSEX, ENGLAND ¡ TEL. HARLOW 26862

The fir st operational SSA 990 system i s now being installed for the Civi l Aviati on Department of the Hong Kong Government

Cossor SSA i s serving Australia, Austria, Bu rma, Denmark, Fr~ n_ce •. Hong Kong , India, Lebanon, Netherlands . Norway.

Philippines, Sweden, Thai land , Turkey , Uni ted Kingdom, Zaire.

Editorial The Annual Conference Still Bigger and Better: Is it Necessary?

The answer is, of course, an emphatic "no". It is not necessary for successive Conferences to be bigger and for Associations to outdo each other in better organisation of Conference facilities. The only criterion, as far as the Executive Board is concerned, is that the work in hand gets done, and gets done well. All other considerations are secondary.

To illustrate, we only have to go back to the last two years of IFATCA history. In 1974, the host Association was Israel, one of our small Associations, which had half of its members in uniform and on active service at the time of the Tel Aviv Conference. As a consequence, the Association had to place the organisation of the Conference into the hands of a commercial concern. The result: a most successful meeting. In 1975, the host Association was Australia, one of our biggest Associations, with scores of willing helpers to put the finishing touches to every facet of organisation, from meeting delegates at the airport and take them to their hotel, to taking them back to the airport and put them on their flights home. The result: another most successful meeting.

The moral for our small Member Associations is: don't be put off in coming forward to apply to hold an IFATCA Conference in your country. If the Icelandic (in 1973) and Israeli Associations can do it so very successfully, so can you. So come forward, and have your Association's application put on the list of future Conference venues.

IFATCA's New Direction That the Federation has moved away from its former direction in the last year or so, has been evident for some time, and probably warrants a few words of explanation, and reassurance.

The Executive Board under the leadership of Daniel Monin believes that the Federation must stand up for what it believes in. If we believe that we are not getting the recognition as controllers that we deserve, or that the safety of air traffic is impaired somewhere in the world, then we must make the world aware of this need, and the reasons behind it. To this end, we must¡ ceomment to the media and to the authorities in question~ matters that affect controllers.

This does not mean that IFATCA has abandoned its faith in the professional organisation approach, or is lending itself to non-professional actions in support of persons or groups of persons in the ATC system. Far from it. But the Federation does move with the times.

And in particular it supports the contention which was re-affirmed at the recent Melbourne Conference and mentioned also in the Conference report published elsewhere in this issue, that the safety of air transport in all its forms is directly dependent on the efficiency of the Air Traffic Control Services, and since ATC-efficiency is itself directly related to the conditions and circumstances of employment of ATC personnel, any delay in working towards a solution of outstanding problems in this area can only be to the detriment of flight safety.

And here is where the Federation comes in.

IFATCA needed a new direction. Our profession is a unique one, and we must behave like the unique professionals we are. This we are doing to an increasing extent.

GdB

"International Law as It concerns the Air Traffic Controller" Mr. McCluskey's popular series on International Law, which have appeared since the decision was taken at IFATCA '73 in Reykjavik to establish a new Standing Committee on Legal Matters, will be continued in our November 1975 issue and subsequent issues. This means that no article appears in this issue.

3

Look at it from the bright our new L Sl•de (w1•"h • ht Di ::a'tJ') Sp1._.z Day.Ilg 1

1

The 23" Graphical Bright Display is a mechanically and electrically self-contained unit, de~i~ned for cooperation with a (m1m) computer.

The display is able to generate and present a variety of computersupplied synthetic information with a high brightness and clarity.

The lightpen enables the operator to assign items on the CRT to the computer, where it may be used for any software action wanted.

In combination with a generalpurpose computer, the display can perform a versatile, operational task in various data handling systems, where a high data load under high ambient lighting is required.

Signaal's latest addition to the already safest air traffic control region in the world, the Netherlands.

Hollandse Signaalapparaten BV Hengelo - The Netherlands. ~Radar, weapon control, data ~ handling and air traffic control systems.

SIGNAAL

"' Iii

The Eurocontrol Institute of Air Navigation Services An International Training Centre Providing Basic, Refresher and Conversion Courses for ATS Personnel

by G. J. d:? Boer

Address of Recognition Efficient training and professional development of the men and women devoting their services to the safety of air navigat ion are undoubted ly the most powerfu l promotors of improved air traffic services, an objective in which staff and adm '. nistrations concur.

To have highlighted so ably the part the Eurocontrol Institute of Air Navigation Services, Lu xem bou rg, has been able to play in this vital field for th e common good of international aviation in the world-wide concert of A.T.S. Training Establishments is a se rvi ce which my staff and I owe with profound recognition to the IFATCA Journal. Thanks to the editor, it has also given us a genuine encouragement and has establ ished a direct personal link to each one of the readers.

G. E. KRUG Director of the Institute

Location of the Institute The city of Luxembourg - which celebrated the thousandth anniversary of its foundation in 1963 _ is situ ated at the confluence of the Germanic and Romance civi li sations, so th at many of its inhabitants speak several languages, and this cosmopolitan note is enhanced by the

presence of a number of institutio ns of the European Communities and the Eurocontrol Institute. With its 80.000 inhabitants, 80 hotels and 1,300 shops in an area of 20 square miles, the city has all the trappings of a modern capital, but at the same time is an inviting haven of peace, popularly known as th e City of Roses. It might have been built with Alphonse Allais's epigram in mind "cities are best located in the country."

The Institute is located in some ten acres of ground on the Kirchberg plateau to the north-east of the city near the Grand Duchess Charlotte bridge, whose massive arch spans the Alzette valley, linking the European Centre on the plateau with the city of Luxembourg. The bridge also constitutes an important link on the main road to Trier o n the Moselle, which connects the Luxembourg highway system with the German motorway network. Immediately adjacent to the Institute is the building of the European court of Justice, and nearby is the 22-storey European centre, which towers above the green belt that enc ircles the city. Development of the Kirchberg plateau is to be completed by an administrative and residential complex and a number of technical training establishments.

The Institute is housed in a modern two-storey building, 85 rn long and 20 rn wide, and has an overall floor space of 3,400 sq.m. some 2,500 of which are given over to

5

teaching facilities. The classrooms are pleasantly light and spacious. The main lecture and conference hall equipped for film projection and simultaneous interpretation {seating capacity 200) is available for symposia, seminars and other scientific and technical meetings of an international character. With an area of about seven hectares, the site - which was made available free of charge by the Government of Luxembourg - is large enough to accomodate virtually any building extensions the Institute might wish to carry out in the future.

The Institute Building was completed in September 1969; the first course began on 5 January, 1970, attended by fifteen ab initio students who were destined to become Area radar controllers at the Eurocontrol Upper Area Control Centre at Maastricht.

The Purpose of the Institute The Training Centre was the idea of two men - the Director General of the Eurocontrol Agency, lngenieur General de l'Air Rene Bulin, and the Director of the Institute, Mr. Gunter Erich Krug, who were guided in their view by the increasing use in Air Traffic Control of automatic data-processing techniques, the chief element of which is the computer. The new techniques had brought with them the need for a stringent review of procedures and equipment as well as the control function itself. It was as a result of their initiative that, in December 1967, the Permanent Commission of Ministers representing the Eurocontrol Member States made the de~ision t~ set up the Institute of Air Navigation Services. It did so with the know1 d e that it was taking a decisive step towards the stanof the operations of the ATC services respondeargd·sation 1 • • • M ·bt for ensuring the safety of air nav1gat1on. oreover SI e • d d t b . _ · the belief that particular attention nee e o e given t int ndardising and improving training facilities - it de~ sda to provide ATS personnel with advanced practical sire . I . t I th' training courses using spec1a squipmen. n is wa!, trainees would be able to adapt themselves to the rapid changes in ATC methods, and developments o~ .ne~ control · and procedures • as well as to fam1hanse them. techmques ·th the 1 ·mportant changes that have occurred in selves w1 . automatic data-processing methods. The importance att~ched by the Eurocontrol auth~rities to th~se matters 1s reflected by the tasks with which the Institute has been entrusted. bourg Institute comprises the following: T h e L uxem b · ·t· (b · ) a) Facilities employed specifically for the a im i.o as1c training of air traffic controllers and ATS as.s1~tant~ of own control Centres. Adm1mstrat1ons ' Eurocon t ro I s . . . re sources do not JUSt1fy .a national Or whose nee d s . · · training sch o ol can enter personnel for this kind of the basic training courses prepare young men . . training; . ·ith a secondary education for a career and women W in Air Traffic Control; 'd'ng advanced and specialised training b) A schoo I prov1 1 . ·n service instruction and special courf - by means o 1 ·enced controllers to keep them abreast ses - f or expen . . . 1 h ges that the introduction of electronic of the ra d 1ca c an . · systems have led to in ATC Centres, data-processing . and for other categories of personnel already working .m A'1r T raff'1c 5 e rv'ices , such as computer programmers, . . . . maintenance engineers and technicians. Trainee techm• c1ans may a 1so attend the elementary parts of the technical courses given at the Institute; 6

c) A centre for ATC instructors providing standardised training planned in accordance with agreed principles of instruction used by ATC Centres and schools. The instructors' courses and working sessions, devised in accordance with principles jointly defined by the Member States of Eurocontrol, are intended for instructors from national ATC colleges and those employed by Eurocontrol. A long-term aim is the standardisation in Europe of the training given to ATS personnel; this will be achieved through courses for instructors, seminars and an annual conference of directors and instructors from national training centres; d) The holding of seminars and similar events like Study Days, Training Conferences, etc. They are an expression of the lnstltute's role as an international forum for the general exchange of knowledge and information and for the cross-fertilisation of ideas on all topics of ATC applied science and technology for the common good of international aviation. Furthermore, they constitute a place from which measures for the better standardisation and adaptation of training to the professional changes imposed by the technological evolution are initiated.

In addition, courses tailored to the requirements of individual national administrations may be arranged on special terms.

The courses which the Eurocontrol Institute provides are so designed as to complement those of national training colleges. Although a significant place is reserved for ab initio training of controllers and ATS assistants, the emphasis in the lnstitute's work is placed mainly on advanced and conversion training for personnel with experience of conventional ATC methods and on courses for instructional and managerial staff with a view to standardising ATS training at national level. The need for conversion training has arisen as a result of the gradual introduction of computers in ATC and this means that users, air traffic controllers and programmers, as well as engineers and technicians, must take a fresh look at their working methods. This kind of re-appraisal is essential both for those whose task it is to define the equipment and procedures to be used in control centres and for those who supervise their implementation. The Institute provides training in the operation of electronic data-processing systems and prepares specialists employed in the data-processing and. maintenance branches of Air Navigation to acquire a basic knowledge of the subject, thereby enabling them to contribute to the many tasks involved in the introduction or further development of automation in the control of air traffic.

The courses offered cover a wide range of specialised, highly technical subjects and the "production" is of a high standard: they take account of developments in the technology, equipment and procedures employed in control centres, thus providing students with the opportunity of updating their knowledge in a particular field or acquiring the requisite basic knowledge for subsequent specialisation in a new field. The technical courses are designed to familiarise electronic engineers and technicians with the different aspects of data-processing and presentation. They are provided at two levels. One, intended for technicians, is specifically concerned with equipment operation, construction and maintenance. The other is intended for engineers with university training, and places greater emphasis on the interdependence of hardware and software.

In the foreground, from left to right, Mr. Renll Bulin, Director General of Eurocontrol , His Royal Highness the Grand Duke of Luxembourg, Mr. Gunter Krug. Director of the institute, and Mr. Horst Flentje, Engineering Director of Eurocontrol , watching a d isplay on a radar screen.

The reasons why programmes of such scope and complexity are offered are s imple but compelling. The prodigious development of aviation has made it essential to improve and standardise trai ning facilities. The volume of the air traffic to be controlled is not only great already but is also expanding with annual growth rates of 10 and 15 O/o, and the present breathing space as a result of the fuel crisis and world economic conditions is not expected to halt the upward trend for long. In few other areas of activity does technical progress influence the working envi ron ment so directly as in Air Traffic Control.

An effort has been made to apply the most modern techniques of in stru ction in all the branches of training, and to this end contacts have been established with the education authorities of several States who are in the forefront of this field of research. As the Institute - as already mentioned - is intended not to replace but to supplement national t raining establishments, its capacity has been determin ed above all by qualitative criteria. Accordingly, the ci rricu lum has necessari ly been oriented towards relatively sho rt and intensive high-quality cou rses. Since the courses are designed to provide in-service and advanced training, this means that th e number of parti cipants are restri cted and not more than a hundred or so students can be accepted on any given day of the lnstitute's 45week year. The number of students per course is normally limited to twelve with a view to in creasing the effectiveness of the instruction given, especially where practical work is concerned. The number of participants per seminar, training conference, etc., is normally not limited. All train ing of Air Traffic Services perso nnel is based on the Standards and Recommend ed Practices of ICAO. The Permanent Commission of Ministers has decided that the Institute w ill be open not on ly to the Eurocontrol Member States but also to other European or non-European countries which wish to avail themselves, on a feepaying bas is, of th e l nstitute's services. The lnstitute's w ide international appeal owes much to the interest shown in it by the countries which cooperate with Eurocontrol in Europe. Th is is reflected not on ly in the syllabus but also in the teaching material. S ince teaching programmes can be used for the t heoretical part of most courses, the instructors concentrate more on guiding and assisting the individual students rather than lecturing in the traditional

manner. The courses, seminars and special one day study sessions, the details and fees for which are given in a brochure published yearly, are therefore open to nationals of all States who wish to avail themselves of what Eurocontrol is able to offer and - since 1972 - certain sections of the programme are also open to experts from private firms in the aviation and electro nic industries and from scientific research institutes and similar bodies (subject to the avai lability of places).

The cost of setting up the Institute was borne jointly by the Member States of Eurocontrol. Running costs are in principle covered by the tu ition fees, but the Member States have to advance funds to bridge the initial gap between income and expenditure.

T he period prior to the commencement of the first cou rses was one of intense preparation. The most important preliminary task was to train the lnstitute's instructors for thei r future duties and engender a tradition of close coordination. The task of imparting knowledge is one which demands not only teachi ng skills but also the fu ll unfolding of the personality and the proper attitude to teaching. The success of a course depends on a great many factors, but the most important is the quality of the teaching staff. If th is quality is lacking, even the best and most sophisticated teaching aids and methods cannot be used to full effect. A comprehensive teacher-training has been evolved, designed to ensure not only that the lnstitute¡s instructors are fully familiar with the modern equipment and methods which they use, but also that the training objectives set for their students are met and that the instructors work in close harmony with their colleagues teaching related subjects.

As an international training centre, the Institute devotes special attention to languages, and mention shou ld be made of the audio-visual methods of language-instruction which are in_ use .. A modern 16-booth language laboratory complete with visual aids has been installed and the laboratory . is used for practice in aviation E~glish and ICAO terminology. This laboratory is also equipped with a Student Performance Monitoring Unit which enables an instructor to assess rapidly the progress being made by his students. If a student has a particularly difficult question, it is usually possible to provide an answer in 7

his mother tongue, and it is in any event the aim to conduct the courses and to provide texts in both the official languages of the Eurocontrol Agency (English and French).

In certain technical courses, German has been added as the third course language. At seminars, simultaneous interpretatio n in at least English and French is provided as far as possible in order to foster exchange of information during the d iscussion periods following the presentation of papers.

By prior arrangement, examinations may be conducted at the Institute in accordance with the requirements of National Admini strations, including, where appropriate, the participation of representatives of the competent national aut hority. Where no requirement for examination is specified, a standard examination may be set by the Institute from which the sponsoring authorities may determine whet her or not the resu lts achieved comply with their particular require ments. In all cases, a confidential report on each student will be submitted to his s ponsoring authority and a certificate of attendance will be provided to each individual.

Each course b egins with a welcoming address by the Directo r of the Institute or one of his staff, outlining the activities of Eu rocontrol and expl aining the requirements of the courses a nd the benefits th ey can bring if followed conscienti o usly. Between periods of w o rk, students will also have an oppo rtunity of getting to know one an other a nd of meet ing their instructors and other members of the lnstitute's staff. Th e time-table is so arranged that the early mo rn ing periods a re d evoted mainly to theory and the later part of t he m o rning or the first half of the afte rnoon to pract ical wor k, the remainder of the school day bein g left free fo r private study. The c irriculum provides fo r t hirty hou rs' inst ruc tion per w eek, a figure based on experience in national establishments. The students also have an oppo rtunity to t ake pa rt in various sports. At the end of each co urse, the students have an opportunity to g ive t heir o pini ons o n th e instruction they have received.

Constru ctive criticis ms are always welco me and, whereve r possible, borne in m ind w hen s ubsequent courses are being prepared. Th is is o ne of the ways in which the lnstitute's t raining is constantly being pe rfected.

As no accomod ation fo r students is p rovided at present, the courses are non-res idential and the fees are exc lusive of the cost of board a nd lodging . Howeve r, the Pe rsonnel Office is at the disposal of students for the purpose of eas ing t heir pro bl ems encounte red in finding suitable hotel accomodation.

The Organisation of the Institute As already me nt ioned, the courses are intended chiefly for air traffic co ntrollers, maintenance tech nicians and engineers, and computer prog ram mers. There are three training d epa rtments, each responsible for o ne of these categori es of staff. They are: T he ATC Department T he ATC Department is responsible for the courses. seminars and co nferences for contro l person nel, at basic and advanced levels. The basic cou rses provide inst ruction in the fundamenta ls of p rocedural contro l, using the telecomm uni cations system and the non- radar working pos itions ; and radar co ntro l, us ing progra mmes simulating the raw radar signals. The advanced co u rses lay more parti-

8

A Controller posi tion in the ATC Department w ith a synthetic Dynamic Display (SOO), an Electronic Data Disp lay (EDD) and fo ur input instruments: a dynamic keyboard, a touch input dev ice (TIO). a rolling ball and a light pen.

cular emphasis on the controllers' future duties in highly automated control centres with equipment fo r automatic data-proc essing and display, using training prog ra mmes designed to simulate synthetic radar s ignals (displ ay of alphanumeric symbols indicating the altitude and identification of aircraft equipped with 4096-cod e SS A transponders). The ATC Department collaborates c lose ly with the Programming Department on the spec ialised courses o n the application of programming techniqu es to Air Traffic Co ntrol.

The Programming Department Th e Programming Department is respons ible for the basic and advanced courses, seminars and confe rences for computer prog rammers and analysts wh o will be working in automated centres. It works in c lose cooperation with the ATC and Engineering Departments, and arranges the speci alised instruction on programming techniqu es for the techn ical and ATC personnel who will have to work with automated data-processing and di splay syste ms. Thi s department is further responsible for the maintenance an d development of the software for th e lnstitute's ATS di gital simulator.

The Engineering Department

The Engineering Department is responsibl e for the advanced and specialised courses, se mina rs and conferen ~es for computer and data-displ ay techni c ians and e~gm eers. This instruction is intended for engineers who will be co ncerned with the design, purchase o r install atio n of d~t~-processing and display equipment, and for the technicians maintaining these facilities. Softwa re is essential t~ e operation of data-processing systems, and the E~gmeenng Department co nseq uently wo rks hand in hand with the Programming Department to ensure that th e technical instruction in cludes aspects of prog ramming.

The three training departments coo rdinate th eir training activities so that in dealing with so complex a subj ect as

!or

the automation of Air Traffic Services, a combined viewpoint, representative of all aspects of the problem, is presented to the students.

As in other Eurocontrol establishments, the lnstitute's permanent staff is drawn from the seven Member States of the Organisation. There is a permanent staff of sixtyone, including almost forty engaged solely in teaching and train:ng. The nucleus of twenty-six instructors are augmented as required by visiting lecturers from the General Directorate of Eurocontrol in Brussels, the Expe rimental Centre in Bretigny, and the National Administrations as well as from training establishments and private industry in the Eurocontrol Member States. The aim is to ensure that the instruction provided is as realistic as possible and to secure the teaching services of the foremost European experts in various specialised fields.

Apart from the training departments, the Institute comprises: the Director and his Secretariat; an Administration-, Finance- and General Services Section which runs the Institute: and a Documentation Service and Language Training Bureau.

The lnstilux System In support of its wide range of courses, the Institute has a computer-simulator complex which is provided with the software necessary for advanced training in new techniques. The lnstilux digital computer-driven simulator for ATC training, in service since 1972, can rightly be cons:dered as the piece de resist ance (key component) of the lnstitute's training equipment.

Before coming to the lnstilux System proper, there are three interconnected non-computerised elements, namely: a) an Ae rodrome Control element: based on projection of aerodrome circuit traffic on the screen and sim ulation of pilot/controller communications. Its purpose is the training of ae rodrome controllers in basic R/ T phraseology and traffic handling. The capacity is 12 students (6 as controllers and 6 as "pilots"): b) an Approach Control element: three separate approach units each linked by simulated R/T and telephone lines to "pilots" and other ground units. It is used for training in procedural methods of Approach Control. Any operational unit can be simulated. and the capacity is 12 students (3 as controllers, 3 as assistant-controllers and 6 as "pilots"): c) an Area Control element: four consoles each of five bay capacity and each representing one ATC sector. They are equipped with comprehensive air/ ground and ground/ ground communication systems. The element is used for training in procedural methods of Area Control.

Any geographical area, real or fictitious, can be simulated. The capacity is 16 students (4 as contro llers. 4 as assistand-controllers, 4 as 'pilots' and 4 as other ground ATC units) .

There is also an independent bas ic radar train er, consisting of two elements: a) an Approach radar element: an analog s imulation system capable of representing performance of any operational radar, inc luding primary and SSR active/ passive decoding. Its purpose is the training in approach radar director duties. Any geographical area- or approach radar unit can be simulated. The capac ity is two radar control consoles having 6 targets, three "pilot" positions each driving two ai rcraft;

..

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-

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.

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The Display Test Bench, Engineering Department.

b) a Precision approach radar element: an analog/digital simulation system giving azimuth and elevation information on one scope. It is used for the training in precis'on approach techniques, and the capacity is two radar consoles and two "pilot" consoles.

The lnstilux System caters fo r the training of radar controllers, computer prog rammers and technicians, by means of a priority interrupt system which permits simu ltaneous ly the ope ratio n of "on-lin e" simulation exercises and "off-line" programmer training. The former has priority, and a supervisor programme is used to introduce the "off-line" task whenever spa re capacity is available.

This room houses the Aerodrome Control Simulator. In the foreground are the pilot Input positions, with the controller positi ons furth er back . The situation on the runways and taxiways is shown on the screens in front of each pilot/controller pair. and the pilot uses Perspex Aircraft Markers for the ground movements directed by the controller.

9

The simulator is based on two Elliott 905 digital computers (one as main processor, one as display processor).

The system is capable of storing 120 flightplans and will at any moment simulate up to 60 aircraft in flight, including SSTs, and simulate their detection by two radar stations, each having primary and associated secondary radars. All transfers of information for display purposes are effected exclusively in digital form. The two computers also drive an extensive display system, consisting of about two dozen cathode-ray tubes. The cathode-ray-tube-operated viewing units are usable both by trainee controllers and by the "pilots" of the simulated aircraft. An advanced telecommunications system allows the simulation of air/ground (pilot/controller) and ground/ground (controller/controller) communications.

With regard to the capacity of the two computers, the master computer has a ferrite-core memory of 49.152 words of 18 bits length, a high-speed magnetic disc store with a capacity of two million bytes and up to eight magnetic tape units. The slave computer, which drives the display system, has an additional core store of 16,384 words of 18 bits length. The master computer drives all the various types of standard peripheral equipment used in the training of computer programmers.

The importance of automatic data-processing to ATC is primarily demonstrated by the fact that the simulator automatically collects, distributes, selects and coordinates all the relevant radar data pertaining to a given situation and continuously presents the processed digitised air traffic data to the controller in suitable pictorial form on synthetic dynamic uisplays (SODs) and in_ t~bul~r form on tabular electronic data displays (EODs), md1catmg the progress of flights, so that he can take the appropriat.e de~isions.

Therefore, a choice can be ma~e betwee~ d1splaymg the flight data pictorially or presenting them m tabular form.

Synthetic dynamic displays have . an advan~~ge over conventional radar displays, wher~ aircraft pos1t1~ns are indicated by blips, in that appropnate alphanumeric symbols are utilised, which move across the scope in accordance with the speed of the air~ra~. Clutter and other · t rterence can moreover be eliminated by radar exme · ·· · th e ra d ar d at a tractors, which are also used for d191tising prior to further processing by the computer. . .

The simulator is so designed as to enable .six s1mutime, each Iat .ion exercises to be conducted at the . same . th' training exercise having two working positions. 1n 1s way twelve students can be trained as radar controllers for _ t ervices at conventional or automated ATC cenen rou e s . .. · f there are up to twelve working pos1t1ons, six o t res. So, ·r h k' · used as a controller wor mg pos1 ion, eac th em b emg · d · wor k.mg pos1·t·10n having a range of modern es1gnat1on . · sueh as synthetic dynamic display, electronic . data d ev1ces .

I k b rd touchwire input display (TIO), rolling ball d 1sp ay, ey oa • . .. . t .. h and light pen. Positions exclusively for p1 1o s ave ~u~posely not been provided, so that t~ain~es whose turn 1t 1s to act as pilot can follow the air s1tuat1on and the ~abular fl .19 ht d at a appea r·ng 1 on the controllers' screens. . , This . also enables them to learn from their fellow trainees mistakes.

The simulator is of course fully equipped to ~nable pr~c­ tical instruction to be given on raw video displays with conventional radar procedures.

A large number of programmes simulating flight movement and control procedures are employed, and a library of about 150 training exercises is available for ATC courses. In common with other modern training aids, the simu10

lator appreciably increases the trainee's experience of computer work.

Vocational training for ATC staff cannot be efficient unless the practical training is as close to real Air Traffic Control conditions as possible and the equipment employed for training is the same, or at least very similar, to that used in an actual control centre. The use of digital computers in ATC, particularly in flight data acquisition, processing and display, means that the training given to control personnel should be sufficiently advanced to allow them to take full advantage of current technology. Great care has therefore been taken to ensure that the simulator and its sophisticated "software", i. e. the programmes needed for the different types of training and associated tasks, will not only be capable of simulating existing ATC environments but will also be able to keep abreast of new developments in the techniques of data-processing and display for Air Traffic Control purposes. The computer system selected for the simulator incorporates the latest developments in ATC automation, and the diagram of the system demonstrates the numerous applications and instructional potentialities of the simulator.

It was decided that - in addition to the training set-up, and with the aid of the computer facilities of the Institute an automated Documentation Centre covering air navigation safety and related topics, should be included at a later stage in the services to be provided. The Documentation Centre itself would be the subject of extensive studies before the precise lines of its development were established.

Other Teaching Aids and Equipment In addition to the training simulator, a variety of other modern aids to learning and teaching are available. The wide range of simulation equipment and demonstration facilities include working models which the Institute has produced itself in view of the highly specialised nature of certain training courses. The emphasis is thus placed on gaining experience in a ~·quasi-live operational environment", using facilities and methods which are the best suited to adult-training requirements.

A type of training which has called for the acquisition of special equipment, is the additional programmer training, for which an Elliott MCS 920 computer has been delivered.

This computer also allows for the testing of programmes destined for the larger 905 models.

Extensive use is made of visual aids - films, slides, etc.

When it seems that the objectives of a course can best be achieved by field studies, visits are arranged to establishments in Luxembourg and elsewhere containing equipment of practical interest. Seminar reports are issued to the participants as an integral part of the services provided.

T~e use of working models are indispensable to the practical application of the knowledge acquired during th~oretical instruction on digital techniques, integrated circ~1ts, and logic circuits. A number of engineering training aids produced by the Institute are in use for the following purposes: training on digital circuits; on microprocessors and microprogramming; on digital display systems; tor radar processing courses; and for training on radar extraction and digitalisation problems.

The Institute prepares its own printed circuit cards for the demonstration models, and these precision products are quite literally put under the magnifying glass during

the design and manufacturing stages. Enlargement of the phototype of the hand-drawn design is the third in a sequence of nine operations involved in the production of these cards; the other operations include design work, photographic processes and engraving.

Two flight strip printers are also in use.

Programmed- and Computer-Assisted Instruction The use of electronics has become widespread in many sectors of economic life, proving one of the most effective agents of expansion. In aviation it is in particular Air Traffic Control, with its complex and varied range of electronic devices, where specialised knowledge is rapidly outdated; electronics experts are compelled to assimilate a constant flow of innovations. With the continuous increase in aircraft numbers and operation speeds, ATC must, if it is to be efficient, make use of the most modern techniques.

For modern man, the enlargement of his intellectual capacity is an imperative necessity, which must, to an increasing extent, prompt him to learn more and to learn faster. We associate the term "education" with the knowledge we have acquired at school or university, but a leaving certificate or diploma is not enough, and figuratively speaking, we must go on attending school all our lives, right up to retirement. Let no one say this is an exaggeration, for it is a well-known fact that in areas such as electronics, for instance, professional knowledge is constantly subject to an eve r-increasing state of obsolescence, so that experts even today have to reckon with renewing their stock of knowledge every five years, if they are to keep pace with the evergrowing requirements. It is axiomatic that in the face of this development not only must more be learnt but this additional knowledge must also be assimilated quicke r than hitherto. It should also be borne in mind that the increased stock of knowledge acquired in a shorter s pace of time must be stored and kept ready for use at all times.

Programmed instruction is a great help to that end.

The programmed instruction ¡at the Institute is very different from the old text-books in that the subject matter is divided up into a series of small steps. Each step follows on from w hat has already been dealt with and assimilated, and any gaps in the student's knowledge are filled before he passes on to the next step. This method is designed to enab le the student to reach his educational objective with max imum efficiency and speed. The advantages of programmed instruction may be summarised as follows : a) at every step performance is checked automatically, and each student is able to progress at a speed in keeping with his own assimilation capacity; b) the qu ality and presentation of the material are Independent of the aptitude of the instructor; c) the student enjoys maximum freedom while participating in a collective learning process.

Several programmes are in use at the Institute, and it is logical that this type of instruction wi ll und ergo co nsid erable expansio n with the aid of the computer.

A large number of simulations can be conducted w i t h 0 u t the use of automatic data processing provided that the exercises are not too complex and are relatively easy to construct, and that the relevant data can be dealt with by means of conventional facilities. C o m p u t e r a s s i s t e d s i m u I at i o n has, however, proved necessary, if not absolutely essential, in cases when:

These students are working at the controller positions on the procedural control simulator. Exerc ises of th is kind employ actual traffic data from the control centres of the area that i s being simulated.

there are a large number of data to be handled (e. g. a large number of tracks of aircraft of various sizes and speeds) ; the exercises are highly complex and seve ral exercises of identical or different content have to be conducted simultaneously; for teaching purposes, the exercises have at any given moment to be "frozen" and restarted automatically, or, also for the same reasons, continuous evaluation and recording are required ; a " conversational" mode is used w ith the simulator taking over certain teaching functions which in the conventional system are performed by the instructor.

The first step in computer-assisted instructio n has been accomplished in that computers can allow for differen t learning speeds.

These new training methods and aids cost far more than conventional methods do, as they necessitate the use of modern electronic data-processing equipment and highly diversified software. Besides being very costly to purchase or rent, a computer has ve ry specific operat ing needs such as air-conditioning and regular maintenance; it also requires - and this is extremely important - specialised and complex softwa re so as to enable it to be used for any specified purpose and to render it cost-effective, at feast from the teaching stand-point. The software also has to be maintained and continually developed. In a word, the computer is an expensive item but it can provide better speciali sed training in the previously mentioned cases, especially where experience gained in a quasi-live operational env ironment can result in the saving of a great deal of the time and effort devoted to on-the-job training.

On average, t he ratio between the preparation and compilation of a teach ing programme and its actual implementation is 50 : 1 ; in other words, every o ne-hour c lassroom session requires 50 hours' preparation. It is t herefore axiomatic that programmed instruction will be a rational solution from the cost-effectiveness ang le o nly if the teachin g programme is subject to comparatively little amendment, remains valid for a long period of t ime, and can be utilised by a large number of students.

11

In training air traffic controllers, computer-assisted simulation makes it possible to confront the student with a wide variety of critical ATC situations and problems which might never arise during on-the-job training but for which his schooling can have given him a good preparation. Thus the computer can bring about a marked improvement in training, both qualitative and quantitative, and can also save a considerable amount of expense.

Trainee/Computer Communication Ever since the digital simulator came into operation, the Institute has been working to optimise the practical training which the simulation exercises provide. A study is being conducted in cooperation with the French Administration with the aim of: a) making the practical part of the training more systematic and more efficient through simulation exercises; b) arranging the tuition in such a way that both instructors and trainees can effectively check on the progress made; c) obtaining a utilisation of teaching resources which is better suited to: (1) the tools available; (2) the tuition provided; and (3) the difference in pace at which individual students acquire knowledge and ATC know-how; d) achieving a more rational utilisation of the teaching staff.

For this purpose it will be necessary: 1) to fay down a general teaching policy for the practical training of students. For radar controllers this would be based on the splitting up of the course into a number of successive phases, the teaching aims, the teaching facilities to be provided, and how these are to be used being specified for each phase; 2) to define in detail the possible methods of using the conversational facilities available, at the same time specifying the operating capabilities that such facilities must provide.

A psychologist specialising in such matters has been made available to the Institute by the French Administration. He has studied these questions with the lnstitute's experts and has submitted detailed proposals which are now being assessed by the Institute with a view to form part of future action in pursuit of the above aims.

Assuming that the practical training of. student. radar controllers will continue to be based essentially on simulation exercises, these exercises can be defined in accordance with the following classification: _ static analytical exercises in "own time" within a specified time; dynamic analytical exercises in "own time" within a specified time; . . . dynamic chronological simulation in real time; final overall simulation.

The equipment to be used for each ~f these types of simulation will have to be defined according to the means available or under development. The Institute has adequate display and computer input facilities. The pro~rammes for the simulation exercises are many and varied but the conversational facilities, i. e. the programmes allowing virtually free communication between traine_e and computer at the trainee's own individual pace, are still at the elementary stage. . . .

The main item is an electronic data display unit showing data in tabular form to which is connected a touch input device (together generally known as EDD/TIO). On the 12

basis of this piece of equipment a management programme of a very general nature has been developed. Its external operation may be briefly described by indicating that in the case of each elementary key of a TIO picture, it is possible by means of a programme to determine the entire EDD/TIO picture which will be displayed on selection of that particular key. All possible sequences can thus be determined starting from one picture, each step leading to a new overall picture comprising tabular data (the EDD part), and the possibilities of switching to the following pictures can also be determined (the TIO part). In addition to this main programme, there are supplementary ones consisting of: a "Display Assembler" whereby it is possible to define externally, simply and in plain language, the whole structure and the content of each of the basic pictures (EDD/TIO) composing it; recording programmes for developing programmes analysing the progress of the exercise (individual and overall analysis). The problem is to determine the uses that can be obtained by integrating an SOD (circular screen) picture with the EDD/TIO unit, and the possibilities to be expected from a "conversational" unit of this type.

Prior to developing these- facilities in the environment in which they are to be used for radar simulation exercises, it is necessary to know: to what extent they can and should be used路1 in what circumstances they are necessary and effective; the tasks they can be expected to perform; what advantage can be obtained for the teaching system as a whole in terms of quality, time and saving.

The results with the experimental programme so far ar~ very pro.mising. It has already proved useful, the simulati~n exercises apart, for various types of teaching work designed to provide immediate reinforcement of the knowledge gained by the student. In the case of programmable tests and samples of actions that can be defined in adv~nce, etc., the instructor can be replaced as "knowledge dispenser" . . t o advantage by the computer. The workshanng is then modified, the instructor devoting himself much m~re to preparation, while the computer performs the considerable amoun t of work .involved in presenting, . . assessing and annotating the student's results Th I 路 . e nstitute has started to use its first end-of-course test programme. The tests take the form of a dialogue betw~en th~ student and the computer in which the instructor will not intervene路 It 路is th us possible . . to compare the merits of ~he conventional teaching method and the computerass1sted method d . . an assess the advantages from the learning viewpoint.

It may be expected that this method will become

gene~al and, provided that it is used properly will be of

considerable assist . ' . . . . ance to instructors in organising their work and opt1m1sing their teaching potential.

The Valuable Work of the Institute at International Level The Institute is a recognised ICAO training school and as part. of ICAO's programme of technical assistan~e to developing countries, ATC personnel from such countries have undergone training at the Institute Apart from the ICAO sponsored students, students from ~ number of other (cont. on page 32)

Value Engineering: Now Applied toATC Design

by H. C. Scott, Head of Sales, Cossor Electronics Ltd. (United Kingdom).

Sufficient experience with advanced ATC hardware and techniques has been gained and shared over past decades that innovations can be considered more confidently in early system planning phases ...

Perhaps the most significant contribution to the solution of air traffic problems and the evolution of ever safer systems has been the almost unbelievable build-up of understanding of new equipments and systems by Air Traffic Control authorities. This understanding, which has been brought about through the work of !CAO and other international aviation-associated bodies, has meant that feed-back to manufacturers from the field- has become progressively more meaningful and has reached the stage where innovations actually start with the planning and operational authorities. In short, value engineering now can be applied effectively to improve the planning and design of Air Traffic Control systems.

Much has been written since 1945 on the needs of Air Traffic Control in the promotion of a safe and expeditious flow of traffic. Progress from a purely procedural system to some form of radar-assisted system has been slow; and, even today these are not universally implemented. It is worthwhile to look at the main underlying reasons for the slow implementation of radar into en- route systems.

Undoubtedly, the conservatism of Air Traffic Controllers is an important factor and one which can be appreciated when their awesome responsibility for the safety of air travelle rs is taken into account.

In the 1950s and early 1960s, technical innovations were leg ion and sponsors bore in on the ATC system planners with claims of "answers" to all the problems; experience has modified these claims and revealed the limitations of some of the innovations when actu ally put into the field .

Nevertheless, the enormous-.cost of introducing new electronic aids has been undertaken by authorities in North America and Europe. Traffic in both regions has grown at a tremendous rate and has presented Air Traffic Controllers with problems mainly associated with the large amount of data generated by aircraft and by the system- management process, including radar data.

Throughout the formulative period, some innovations have slowly become th e basis of all modern Air Traffi c Control systems and these are readily id entified: Data processing equipment High speed data and radar displays Radar digitisers Data transmission systems Secondary surveillance radar (SSA) New high accuracy airborn navigation systems.

Elements of Today's Systems Before presenting the results of value engineering in the use of ATC equipment and systems , it is necessary to say a little more about the principal elements of the modern system and to trace the changes w hich have taken place under the influences of the operational requirement

H. C. Scott

and the availability of sign ificantly better electron ic components.

Major improvements have red uced the size of data processo rs for equivalent or increased power. Reliability has reached a very high level, which matches o r outstrips other elements of the ATC system. The cost of small volume, high performance processo rs allows their introduction into other elements of the systems as sub-units w ith great advantage - software packages for routine work have evolved to "off-the-shelf" avai lability.

The technical advance in high speed radar and data displays has been very significant, reflected by their capability to accept a large data load when operating as data displays and to present c lear p ictures of radar and other background data to air t raffic controllers with added alphanumeric informatio n. Technical advances in deflection systems and new phosphor capabil ity have been the main contributing factors.

Radar digitisers (plot extractors) have improved to the point where ATC officers accept the fact that data provided are valid for thei r purpose. This has resulted from advances in target detection , reached by a combination of better digitisers and significant improvement in the basic video processing f unction of new primary radar equipment.

Data transmission systems have provided one of the difficult areas to improve in the system; the transmission of raw v ideo over long distances by broad-band eq uipment 13

Thelnt~t~ubk1wtlbe

1SO • ZW '"" Jone in otder to

c-a. the~ltQ • lhown

p. ., Pfinltt

The res..::: of applied value engineering is reflected in this block diagram of the Cossor SSR 990 i nstallation planned for the Hong Kong ATC system.

has in the past been expensive, often prohibitively so. The acceptance of digitised radar data and the introduction of high grade radar digitisers have made data transmission over high grade telephone lines and narrow-band radio links a standard low cost system, taking advantage of ex isting commercial terminal comm unication modems and multiplexers.

The most significant advance has been the introduction of airborne SSR transponders into aircraft, together with height encoders and digitisers for the automatic transmission of altitude to ground stations. The wealth of data provided by the SSR system can be presented on the ground as required with new high speed displays. Other major advances have been made in reliability ~nd in overcoming s uch inherent system prob lems as multipath reflections and non-synchronous replies (defruiting).

A combination of a ll t he new equipments has resulted in the build ing of two new experimental secondary radar systems for the future - Discrete Address Beacon System (DABS) in the United States and Selectable Addressable Secondary Radar (ADSEL) in the United Kingdom. Briefly, aircraft will be cal led as required which will e liminate any resid ual basic problems and only collect the radar data requ ired for operational ATC purposes. The ~e"':' systems also provide a large measure of data trans_m 1s~ 1 on ~apa­ bility which can be used to pass aircraft nav1gat1 onal information to the ground system.

Advances in the accuracy of airborne navigation systems have been continuous, passing through the introduction of inertial equ ipment to new avionics for use with stationery Earth satellites and better_ long range ground syste ms. Such information could be invalu_a_ble to ground control , and the data transmission capability of ADSEL/ DABS w ill meet this requirement w it hout financial penalty to airline operators.

14

Value Engineering Philosophy The philosophy of value engineering can be simply stated as the post design engineering of an equipment or system with the aim of improving the original. Befo re undertaking a value-engineering exercise, it is therefore necessary to define very clearly the objectives in exactly the same way as is done at the time of developing and engineering the original.

The main elements of · the modern ATC system have been proved in large systems and will continue to be improved under the influence of experience in use. This improvement capability has been made possible by the introduction of digital technology with its high capabi lity components and software flexibi lity.

Before embarking on a major ATC value-engi neering programme, some f ive years ago, it was decided that the overall objective wou ld be to examine the system and make the necessary changes to enable the benefits to be avai lable to any ATC authority, in a form suitable for their needs and at a cost consistent with the requirem ent .

Before c lose definition of the objectives were made, six items were considered: cost, functional flexibility, ease of operation, installation and maintenance, expandibility and training.

Cost effectiveness ranges from the cost of individual equipment, through installation and c ivil engineering costs, to manpower reduction . Functional flexibility is associated w ith the capability to optim ise system use and plan expansion w ithout redu ndancy. Ease of operation concerns man-machine operation, be it controller or su pport personnel. Installation and maintenance requirements w ere considered to be most important aspects of the exercise and covered system configurations which could benefit both aspects. The need for the capabi lity to expand has long

oeen recognized but has always proved most difficult to achieve without creating redundancy and experiencing unacceptable costs. (Digital techniques called for new thinking on application.) Training aspects, such as operator, maintenance and ATC planning, were examined; the first and last included simulation.

Objectives Determined From the study came the following objectives : The optimisation of system elements by the application of low cost, high power, data processors; The development of standard software for radar processing; The examination of hardware to produce maximum mechanical flexibility; The optimisation of system status by data processing, including diagnostic programmes and assistance to maintenance; System improvement by overall evaluation of world-wide requirements and continuous inputs from the evaluation of the other objectives, and The simplification of equipment and installation.

Before describing the practical results of the application of value engineering to the modern Air Traffic Control system, it is interesting to note that the users who will not require an automatic or semi-automatic system for some time were not overlooked. The biggest problem for the users of a manual radar system has been one of defining the layout of the secondary radar controller operating panels and the mechanical integration into a consol e.

By a re-arrang ement of digital elements in the standard system, it has been found practical to produce modules based on individual functions which plug into a suitable mother board. The mechanical configuration can be vari able to a high degree and readily expandabl e to increase the number or function of modules. A further objective of value engin eering has been achieved by the application of a simple data highway as an alternative to the involved multi-way c able installation.

Perhaps the most unusual achievement is in how the cost-effectiveness objective is met. Before the introduction of the multi-role system , each system had operator panels defined for the specific requirement and were th erefore special and mad e in small quantities. The modules for the multirol e system are manufactured in qu antity and call ed down by the system engin eer as required ; this redu ces the cost of the system in addition to the install ation-cost savings. Reli ability is increased by virtue of a sign ificant redu ction in th e number of connections and cables.

Achievements Made The work carried out on the manu al system pointed the way to an important area of investigation in the value engin eering of the auto matic an d semi-automatic ATC system. If the work involved in manu al SSR v ideo processing could be re-arranged between the central decoder and the operator module to such advantage, could it be of equal advantage to look at re-a rrang ing the work of a cent ral data processo r to in clude the operator d isplay position?

Once the decision was made to look at a generation of controller displays, which inc lu des a data p rocessor as an integral sub-system, t he answer was obviously in the affirmative. Th is considerat ion became the central theme of

Tech nological advances in high speed displays have been signifi cant in recent years. Typical i s this uni t, one of the Cossor 2000 series displays. showing data l oacJ.

the value engineering exercise, and all other object ives dovetailed into t he final achievement almost in t he manner expected by law in physics.

The integration of the data processor has allowed the formul ation of standard rad ar software packages to cover the controll er requirements and further software for other display housekeepin g to provide high g rade video maps, flight plan information, inte r-co nsole markers, time, runway visual rang e, etc. It was a short step to the int roduct ion of a data highway system ph ilosophy and each display position function selected by the insertion of a coded key. Special keys indicate maintenance or training. The main programme and data from real time sensors flow continuously round the data highway and the insertion of a display key allows auto matic programme load for the display in a matter of some ten seconds.

The problem of moving to another display is the simplest of operations and is almost instantaneous. Transfer of targ ets fro m controller to controller is positive, simple and usually w ithout voice intervention.

The display range includes equipments wh ich display raw prim ary radar w ith superimposed secondary radar labels and fully synt hetic presentation of digitised primary and secondary radar. The prog ress from the mixed display to the syntheti c display only involves changing the cathode ray tube from one having a mixed soft and hard phospho r to one having a single hard phosphor.

The central processor is selected to meet the total system requirements ; but, a central processor identical to the one used in the display has a considerable processing capabi lity when associated with suitable input/ output devices and w ill meet many other requirements. Expandibility is s implified by virtue of the amount of routine load taken by the display processing, which includes display data refreshing in addition to providing the individual housekeeping functions.

Data entry is accomplished at a display position using fixed formats and under central programme valid ity checking before entry. All data inputs are printed on hard copy for record purposes. A facil ity exists for t he digital information on the real-time situation to be output from the

15

central processor for recording on a standard tape recorder. An analysis programme can re-constitute the real time situation. The data highway and internal display processor simplify and reduce the cost of installation and ease the maintenance task.

Diagnostic software programmes for the display element allow the introduction to the display of a maintenance key which ensures automatic loading of the main programme for routine or remedial work to be carried out and inhibit input to the main processor until the maintenance key is removed. Diagnostic programmes for the main system are simplified by eliminating the need for display checking by the central processor. In a dual processor system, the changeover of equipment from unserviceable to serviceable is automatically under central processor control with manual over-ride. The criteria for change are applied to a continuously running check programme.

The use of a "Training Key" and standard operating instructions written into the main programme provides a familiarisation training exercise to take place under supervision (e. g. inputs can only be accepted by the central processor by two operations of any executive key). The use of the maintenance key allows engineer training to take place on a fully loaded display without additional restrictions.

To further expand the inherent training capability of this system to include simulation calls for simulation so~tware to be used in the redundant central processor or tn the central processor of a single channel system. out of hours t 0 ther with dummy pilot consoles. The display system -~~ "simulation" keys will then be loaded automatically 1 wfrom the simulation central processor . . data highway. .

The results of the value-engineering exercise are n.ow · practical use and • the problem • of meeting pu t ·nto 1 b emg the operational requirements of different users 1s apparent.

Hong Kong Air Traffic Control system, for example, Th e new . "t f t . b . ·1s based on th"is concept and expansion; 1 s u ure 1s eing . d confidently, even at this early date of development. planne (First published in ICAO Bulletin)

"Not on your life," he says. "I should find it too hard to settle down - I think people start to 'rust' when they retire.

I shall stay on in an advisory capacity for as long as I can, although I am really now the general dogsbody, collecting landing fees, looking after hangarage and paying godfather to the student pilots. On a busy day here we have some 400 movements so I'm kept on my toes most of the time."

In 1939 Ash saw an advertisement for ATCO's in a newspaper. He attended a training school in Kensington, becoming a controller, first at Croydon, and then Perth at the outbreak of World War II. At the end of 1940 he joined the Air Transport Auxiliary, flying during the day and controlling at night. He re-joined ATC at Renfrew in 1945 and up to his retirement from the Ministry worked at Edinburgh.

OAC Gloucester, Filton, Bahrain, Cyprus and finally Rhoose, only to get in harness again at Sywell until 1974.

Ash says: "I've grown up with air traffic control and seen all the sophisticated equipment and techniques take over gradually. In my day there was no RT or radar everything was done by morse-code." Times have certainly changed. Ash recalls the early days at Croydon when, if an aircraft was coming in to land, the controller used to listen for the sound of the engine and then decide whether it was north, south, east or west. Very often traffic noises from nearby Purley Way got mixed up with aircraft engine noises, all helping to confuse the issue. Heston then brought out the ZZ procedure - this involved the controller going on to the airfield and listening for the approaching aircraft. As soon as it was heard ZZ was signalled and the pilot started his descent, hopefully to land on the runway.

Ash has held a PPL for many years and has flown many light aircraft. It was his ambition to have 150 different aircraft types in his logbook before he gave up piloting - an ambition he achieved in November 1973. He now has 153 types and will continue to fly, in the right hand seat.

(Anne Noonan in AIR Way)

New Air Traffic Control School In Sweden A new school for training civil and military air traffic contra! staff has been opened at Malmo/Sturup Airport, replacing the civil school at Bromma and a military one at Hagernas.

Brief News Items Alerting Controllers to Potential Conflicts New software routine for enroute air traffic control com· d to automatically alert controllers to potenputers, d es1gne . . · fl' t b tween aircraft flying above ,29,000-ft. altitude, t1al con 1c s e . ·onal evaluation at FAA s Center . m Kanhas begun operat 1 ·t The software routine, developed by Mitre Corp., C t . D d sas C I Y. · d out at the enroute en ers m enver an . also b e t ne will

Located next to the control tower, the school has a floor area of 6,500 m2 (70,000 ft2) and a maximum accomodation of 200 students. A computer and systems simulator enables various air traffic situations to be simulated simultaneously on 1.2 synthetic data display screens; it can handle u~ to 90 aircraft at one time. The computer can store 4,000 flight plans and 500 practice plans.

Total cost of the school was about $ 5.8 million.

(AIRPORTS International)

Ft. Worth.

The Remarkable Mr. Ashburner

The Inertial Navigation System

ATC is generally looked upon as a young. man's profesOne such . b ut , as w1'th e very rule · there are, exceptions. s1on, , · · L' I Ashburner or Ash as he prefers to . . exception 1s 1one be called _ who until last year held a valid ATCO licence ·n charge at Sywell Aerodrome, Northand was t h e ATCO 1 , , .

H' ge? . was 75 when amp t ons h ire. 1s a . Believe it or not, Ash he lost his licence as the result of a not-quite-perfect electrocardiogram. So he is now to retire?

Approximately two thirds of all Trans-Atlantic flights are now using INS as their primary navigation aid and are generally recording system accuracies of two or three miles at the end of Trans-Atlantic crossings. In 1978 all airlines using the North Atlantic route structure will be required to carry INS or equipment of comparable accuracy. It will then be possible to organise a more economical route structure by reducing the current separation standardSio

16

How Canada Tackled Its STOL Project ATC Considerations Were Major Issues In 1970 the Science Council of Canada recommended that the Canadian Government encourage and support the development of a STOL Air Transport System. The Council made this recommendation because it was convinced that such a system would be beneficial and that Canada enjoyed a substantial lead in the technology required for the development of such a system. This technology existed because of experience gained in the field of aviation by such organizations as DeHavilland of Canada Ltd. and Canadair Ltd. The Government accepted the recommendation and high-level discussions began in the Ministry of Transport, Department of Industry, Trade and Commerce and the Air Industries Association of Canada concerning ways and means of implementing the recommendation. In August 1970 the Ministry of Transport established a Civil Aviation Branch V/STOL Committee. This committee was made up of representatives of the various divisions of the Civil Aviation Branch and its aims were to coordinate efforts in V/STOL activities; to examine the requirement for V/STOL standards; to collect operational data and gain experience in V/STOL systems development; and to identify and recommend development programs for equipment, facilities and services that would be required for V/STOL operations.

In April 1971, on the recommendation of the Committee, the Canadian Air Transportation Administration formed a STOL Project Team. This team was to expand upon the work of the committee to include the implementation of STOL system trials to test and evaluate components of the proposed system. The project team was made up of five full-time members and representatives of the various branches and divisions which were to be involved. The full-time members of the team established a STOL Project Office and it became the focal point for all project activities.

Representatives of the branches and divisions, including the Air Traffic Services Group, carried out their work from their regular offices, with frequent visits to the project office for meetings and discussions.

Shortly after the project team had been established it was decided that a full-scale passenger carrying demonstration service would be implemented. This service would be operated between a STOLport to be developed near the Expo '67 site at Montreal and another to be developed at Ottawa's Rockcliffe Airport. The idea was that the project team would develop the entire STOL Air Transport System and then turn it over to a subsidiary of Air Canada to operate. The subsidiary was subsequently established as Airtransit Canada.

Because of the impact that a STOL Air Transport System was likely to have on the Air Traffic Control System, the ATS Branch has been involved in the planning and development work of the project from the beginning. With the. formation of the STOL Project Team the tempo of ATS activities inc reased considerably. . • .

Two working groups were organized in the branch - one to develop Air Traffic Cont~ol procedures and techniques for the control of STOL ~ircraft and the other to carry out planning and coordination for the procurement of control towers and associated

equipment and to arrange for staff to provide airport control service at the STOLports. These working groups were made up of personnel from ATS Headquarters, Regional Offices and the operational units concerned. Because the STOL service would operate between Ottawa and Montreal, it was necessary to consult and coordinate with both the Ontario and Quebec Regional Offices, IFR Units at Ottawa and Montreal and control towers associated with conventional airports in both these areas.

It was decided that the demonstration service would provide 44 flights per day (22 in each direction) throughout the week and a reduced schedule on weekends, between the hours of 7:00 a. m. and midnight.

As might be guessed, when the team first considered this from an ATC point of view, it looked at the existing system and tried to develop a plan to integrate STOL aircraft with conventional aircraft using regular VOR airways, radar vectors, etc. It soon became clear that because of the large number of flights and the complications which would be created, especially in the terminal control areas, integration of this traffic simply would not work. The team then began to consider ways to segregate STOL flights from other flights and to allow them to operate pretty much without the assistance of radar vectors. This would avoid increasing controller workload and overloading communications facilities. It was resolved that area navigation (RNAV) would provide the capability to do these things and so planning began for the use of R-NAV as the primary navigation system for STOL operations.

After consultation and coordination with other members of the project team, the .procedures group set out to develop procedures for the control of STOL aircraft based on the use of R-NAV. This began with the establishment of R-NAV criteria to be used in the development of A TC separation standards, procedures and techniques. In order to derive greatest benefit from the R-NAV system it was decided to use a system of flight profiles for STOL operations instead of the conventional airway system. These flight profiles consist of predetermined track(s) and altitude(s) to be used during the departure, enroute and arrival phases of flights, including alignment with the Microwave Landing System (MLS) for an instrument approach to the STOLport runway.

The requirement for steep approaches and the presence of tall buildings, bridges, hydro lines, etc. near STOLports precluded the use of conventional precision landing aids at STOLports. In an effort to select an alternative to this, members of the project team conducted considerable research and evaluated three Microwave Landing Systems that appeared suitable: TALAR, MODILS and COSCAN. COSCAN was eventually selected as the precision approach aid for the STOL demonstration service.

Airtransit Canada have operated the STOL commuter route between Ottawa and Montreal on a trial basis for quite some time, using six DHC-6 Twin Otters which - apart from basic flying instruments for IFR flight - have comprehensive avionics to permit precision navigation with adequate back-up. Inside the aircraft, centrally located within reach of either of the two crew, are twin ADF. VOR. 17

for the branch. Several control tower designs were con· OME, MLS, VHF radio installations, transponder, radio altisidered and the Skykeesh S-100 was selected as the most meter and flight director. The heart is a Litton R-NAV system appropriate tower for the demonstration. Each region was which performs all navigational computations based on asked to provide staff for the STOLport tower and to ensure reception of VOR/DME beacons. The 100-mile route, which that this staff was trained in time for the commencement is flown between 3,000 ft and 8,000 ft altitude, is through of the demonstration service. Also, coordination was carried a complex, controlled-airspace region and involves flying directly over Montreal International Airport. This is only out with regard to the procurement of tower equipment and supplies. feasible because R-NAV makes accurate track keeping possible and the philosophy behind the installation is to Very close liaison has been maintained with both the give the aircrew one, if not two, backups to any major Quebec and Ontario Regions and periodic briefings and meetings of all concerned have been led. Also, many of system. the personnel involved have had an opportunity to take a Prior to the flight, the pilot receives his complete flight familiarization flight in the STOL aircraft and have observed clearance in detail (but coded in format) from ATC. This the use of the special airborne equipment and in-flight will be one of the eight STOL profiles which have been procedures associated with the operation of these aircraft. defined for the route. The profiles are carried in the cockThe control tower at Rockliffe began operations in pit in the form of a series of punched cards. Each is capable February 1974 and the remaining facilities at this STOLport of carrying up to 15 three-dimensional waypoints (altitude, have been completed since then. Some delays were exlatitude and longitude), one card usually defining the perienced in completing the facilities at the Victoria STOLcomplete profile. These cards are used to instruct the port in Montreal, but these are now in operation. computer and are fed in via an automatic data entry unit.

The first waypoint is the threshold of the take-off runway A new stage in Canada's STOL project was reached recently when the service was increased to 30 flights daily and from then on the computer presents navigation information on two flight director displays and also as digital each way, with departures every half hour between 07.30 readouts on the computer display unit. This information and 22.00 hours. A new era in Canadian transportation has begun. is based on details received from ground-based beacons rather than an inertial platform. Present position, distance(adapted from an article by K. J. McDonald first published In the and time-to-go and cross-track deviations can be shown.

CATCA Journal) Should any part of the flight plan have to be changed, due to ATC requests or for other reasons, it can be overwritten simply by inserting a new punched card; alternatively, additional waypoints may be typed in using a keyboard.

Reception of enroute radio be~cons is automatic~lly. monitored by the computer, which 1s capable of momtormg up to 16 beacons simultaneously. The punched card contains information on the optimum beacons at any one point in the flight but, should an unserviceability ari~e, the comThe Air Traffic Controller's Creed puter can locate an alternative without degrading the naviAs a professional air traffic controller recognize my gational outputs. Data can also be fed from the computer obligations: to the three-axis autopilot, so that from take-off to . To the aviators who entrust their safety to my skill and h the flight can be entirely automatic. With R-NAV approac , . ATC . . . . d Judgment.

1s mm1m1se . and a transponder, communication with To my fellow controllers and supervisors who mutually The STOL profile delivers the airer.aft to the to~ of the depend upon me to follow established good practice.

MLS descent pattern, which has a six-degree ghdeslope . To my subordinates who look to me to exercise my best tional reasons, a three-degree offset localian d , f or opera .. d h JUdgment and leadership. ser. Additional airfield aids include a DME pos1t1one alfTo my fellow co-workers who are constantly striving for way down the runway, and traditional VASIS to back up greater achievement and general overall improvement in the MLS. During the approach the R-NAV .presents DMEthe air traffic control system. originated glideslope and azimuth information.

To discharge these obligations I will at all times ob't says that the COSCAN MLS (developed by the .rt A1 rans1 . h. hi · serve ~he highest standards of my profession.

AIL Division of Cutler-Hammer) is pr~~mg 19 Y. satisI will never knowingly jeopardize the safety of an aviator factory in service. The MLS is only cert1f1cated for this one by undertak!ng a risk to satisfy personal desires, nor will I ·t nables Airtransit to operate down to weather control traffic when my mental or physical conditions might rou t e b ut ' e ·1 . 'b'l'ty ( 'th t minima of 400 ft cloudbase and one m1 e v1~1 11 w1 ou lead t~ additional or unnecessary risk to an aviator.

MLS the limits would be 800 ft and two miles.) The comI will use all means at my disposal to assist the aviator e limits reduced to 300 ft and threepany h opes t o have th . . in the safe conduct of his flight. ·1e The Twin Otters are equipped with qua rt ers of a m 1 · I will continue to keep abreast of air traffic control devespecial instrumentation to monitor R-NAV and ~LS .Pe.rlopments so that my judgment, which depends largely on ·1 t workload · As the whole route lies w1thm f ormance an d p1 o such knowledges, may be of the highest order. al track holding performance can ATC ra d ar covera ge , actu I will reflect through my deportment, both on and off be evaluated. duty, respect for my profession and for my country and it Work also had to be taken in hand with regard to t~e shall be such as to bring credit to both . . 't'ion an d .mstallati'on of control towers and assoc1aI pledge adherence to these principles for the advanacqu1s1 ted equipment, and the provision of control .staff for each cement of air traffic control and to further the dignity of my profession. of the STOLports. Most of this work was earned out by the ATS Headquarters staff who normally handle these items (SFC Herbert L. McCormick In U.S. Army Aviation Digest) 18

Future Commercial Air Transport Developments: Its Implications For Controllers And Pilots~)

by J.E. Steiner, Vice Presldent-Tedtnology and New Program Development, Boeing Commercial Airplane Company

The Situation From its humble beginnings many years ago, the commercial air transport industry grew through a period dominated by a relatively few great leaders. Then came ·the decade between about 1957 and 1967 when air travel and revenue passenger miles grew almost three-and-a-half times. We thougth at the time that it was due to the introduction of British and American jet transport equipment.

We realize now that the forces at work had deep economic roots, and what was really going on was the crossover between discretionary income and cost of travel. It's true that our aircraft and our operations affected that crossover, but the powers were fundamentally economic in nature and still are.

Originally we concentrated on simply flying reliability and safety. When I came into the commercial air transportation business, concentration was on performance, speed and range. Safety and reliability were reasonably welle~tablished axioms. It stayed that way until perhaps 1968, with the last years of that period encountering a fundamental change that we in the manufacturing industry had not fully anticipated. The transportation system was maturing, and economics was becoming the paramount parameter. Top considerations became economics and ease of the availability of service, lumped into the word "frequency". · At the same time, another fundamental change was going on. It can best be illustrated by a change in the pressures and constraints of transportation. We learned long ago to live with economics, utility and technology.

The influence of two other' areas - social values and political/regulatory (particularly the former) - have become much more important and have injected another whole dimension into our expanding commercial air transportation system. We are only now on the eve of real expansion, and our predictions of revenue passenger mile growth are backed up by massive demographic data and by estimates of the discretionary income travel cost crossover referred to previously for world areas of population. World revenue passenger miles are shown in figure 1 with a low band and a high band, as must be expected.

In spite of fare increases, the majority of the world's airlines are operating either at a loss or at a profit so thin as to be totally inconsistent with the stable platform needed to launch future expansion. To cover all of the factors involved is beyond the scope of this address, but we might me.ntion two. First, of course, is the fuel price. In the United States it has doubled. We expect that it may peak out and in constant dollars decrease somewhat. In current ~olla~s, it will, of course, continue to increase with the inflation rate. The non-U.S. siutation has, in many cases. been much worse. Even if prices can be maintained at their present levels in constant dollars, the whole formula for h' *) An ex t ract from a presentation entitled "Commercial AlrmanAircraft", made by Mr. Steiner to the Guild of Air Air Navigators, London, October 8, 1974.

~il~ts 1~n=ut~re

air transportation will have been seriously changed. The changes affect not only the manufacturer of aircraft and engines, but they also affect the routes of airlines, importance of airport constraints and holding patterns, en-route navigational accuracy, and a great deal more.

Another fundamental that has changed is the influence of community noise. We as manufacturers have had to make our airplanes quieter, in order to meet the regulatory demands of FAR 36 and ICAO Annex 16, in comparison with FAR 36 levels and with the objective outlined in the CARD report of 1971. In the approach case, we find that the CARD future objectives lie below the noise of the airframe with no engines at all, and thus our ability to meet the future objectives is open to serious question. While the production lines for the 727n37/747 have all been changed to airplanes having the lower values, the expenses involved in the 707 program have proved to be too high for the industry. Technically, the improvements are available; economically, they have not come to pass. On your part, a great many noise-abatement procedures have been used and many more have been studied.

Community curfews, complicated approach and takeoff procedures, routing and increased avionics will all adversely affect the already deteriorated economic situation of the air transportation industry. It is on this uncertain foundation that we must build the expansion of the air t~ansportation system of tomorrow. Perhaps a few illustration~ would be of interest. Figure 2 shows predictions of terminal area delay cost in the near term between now and 19~0. ~fte~ a steep decline in 1971, the data available to Boeing indicate that. the incidents of reported d I · d · e ays increase in 1972 and 1973. We could postulate that by 1980 we might again be at the 1969 penalty revel. The trend. of these delay costs can be inferred also by the increasing number of U. S. airports that will become satu~ated. These conditions are predicated including planned improvements such as new runways, procedures and equipment. In some cases where improvements were not m d as predicted, the situation has occurred or will occur a ~ lier. Besides the problem of additional airports or ru nways, ear demands for ATC services must be considered. A b hub . like Chicago, assuming two airports and the opt·1m1st1c . u~y . traffic growths of figure 1, will generate 1985 d shown in figure 3. emands

Future ATC System . The simple answer to supporting more air traffic is to increase the number of runways and a"rf"eld ..

1 1 s. However .m add1t1on to the constraints considered in the : economic and r· past (1. e. po 1t1cal constraints that are more prevalent today, ecologi.c~I concerns will further compound the problems 0 ~ providing timely relief by new airports. Therefore · commerce, maximum . for continued growth of air use must' be made of existing runways and limited air space.

Current U.S. planning calls for an orderly progression from today's ATC system through an Upgraded Third Gene-

19

World Revenue Passenger-Miles· TOTAL SERVICES

~

1,000 ~

--

ANNUAL G1tOWTtt RATU

1SD

TOTAL NON U.L TOTALU.L 9"~

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REVENUE P'ASSENGERMILES 600 (BILLIQNSJ

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WORLD,.F

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-~?Z

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1965 1970 YEAR END

1960

1956

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L"~ ~ i _, ~~ !AJllUllES

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1950

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1975

1980

1985

Figure 1

Terminal Area Delay Cost

1964

1966

1968

1970

1972 YEARS

1974

1971

1978

1980

Figure 2

Demand for ATC Services 1970 vs 1985 YEAR

PEAK BUSY DAY PEAK HOUR INSTANTANEOUS (OPERATIONS) (OPERATIONS) COUNT (AIRBORNE)

1970

1835

122

30

1985

3334

273

87

BUSY HUB

EXAMPLE AIRPORT: CHICAGO

Figure 3

ration system to an Advanced Generation Air Traffic Management System still in the planning stage. According to the FAA, the pattern of change has already been set.

The U. s. ATC system of the next decade (Upgraded Third Generation system) will contain massive automation and expanded use of transponders. The necessity of expanding the capacity of existing airports will require that the current instrument landing system (ILS) be replaced by a micro20

wave landing system (MLS). The more sophisticated MLS installations provide greater airspace coverage, allowing curved path approaches with variable elevation angles.

These installations will support Category Ill operations and allow a higher metering rate on approach. To overcome undesirable traffic concentration will require an area navigation (RNAV) capability, and an RNAV circular airspace structure is now planned for all busy hubs.

The Upgraded Third Generation system will provide advanced flow control and greater automation through the implementation of a beacon system that incorporates a digital data link. The link transmits ATC separation messages up to the aircraft, while the aircraft replies automatically with altitude and control acknowledgement messages.

During the mid-1980's, air carrier operators are anticipated to transition to 40 (30 plus time) area navigation.

One concept that would apply 40 area navigation to the airspace near high density airports is called strategic control. The basic concept is that each arriving aircraft will fly a planned three-dimensional approach path up to the outer marker, according to a precise time schedule assigned by ATC. ATC will then use the aircraft's ability to predetermine its position in space as a function of time to sequence and space the arriving traffic.

The strategic control concept requires a means of position determination, a navigation system, a digital data link, and a central data processor. Figure 4 illustrates the system elements. The VOR/DME would provide the navigation environment with use of a microwave landing system (MLS) in the terminal area. The surveillance system would supply horizontal position and altitude data to be used as initial conditions both for route-time profile generation and for conformance monitoring as the flight progresses.

A digital data link would connect the air-line navigation/ guidance computer and the ATC central data processor tor transmission of airplane related data. The central data processor will store the program and data, generate the route-time profiles and compare surveillance measured position to assigned position as a basis for conformance monitoring. The controller would function primarily in an air traffic management role. His main tasks would be adjusting the computer program configuration to match conditions and monitoring system status.

A specific example of the increase in capacity available from using strategic control is seen in the analysis of the various control concepts to support the increasing traffic demands of the Los Angeles terminal area (fig. 5). If manual vectoring were to be used, delays would become totally unacceptable in a short period of time. In comparison. studies have indicated that the strategic control concept should be able to maintain average busy-hour delays to less than 6 minutes even if traffic were to double that of 1972.

Strategic control capitalizes upon automation in the Air Traffic Control system and upon the precision navigation capability inherent in modern aircraft. The importance of arrival accuracies to runway acceptance rates needs no illustration. The 2-second outer marker accuracy available with strategic control can increase runway acceptance rate by 14 % to 30 % over the 8-second accuracy expected with ground-based computerized spacing control.

Manufacturers' Actions We should perhaps cover some actions that we as manufacturers can take: that is, actions to save fuel.

actions to reduce noise, and actions to improve air space utilization. The first action we took after the fuel crisis was to advise all our customers of ways of saving fuel with their present aircraft. These generally involved operating procedures, although maintenance procedures were also noted. The total saving available through airline operational techniques was as much as 9.1 O/o or 2,760,000 gallons per day for the Boeing fleet used by U.S. airlines. Fuel conservation is one area where area navigation pays off. The three F's of fuel conservation - fly higher, fly slowly and fly accurately - result in the need for area navigation for accurate flights. Each minute of early descent in a 707 costs 80 pounds of fuel; on a 747, the cost is 200 pounds/ minute. It should be noted that the first major fuel saving improvement can be obtained through improved Air Traffic Control and that automatic flight management offers a very sizable additional improvement when and if it is absorbed into the total system.

The second item already covered earlier is noise. The Boeing Company has spent some $ 85 million over the last 18 years on developments for noise reduction. We have conducted extensive tests on noise reduction through operational procedures. Figure 6 shows the results of tests carried out on two-segment approaches and, in addition, shows the effect of flap angle. The noisiest profile, of course, is a low-altitude, flaps-down, gear-down approach.

Higher glide slopes, higher intercept altitudes, decreased flap settings, two-segment approaches and decelerating approaches are all methods of reducing noise. As a whole, they are far more potent in terms of reducing community irritation than are the developments that can be applied to the engine or even the airframe. The last named, the decelerating approach, is currently being practiced on a very small scale by certain airlines. Its widespread use probably requires automated equipment.

In the takeoff regime, engine cutback is, of course, a potent method of community noise irritation reduction. Information on flight procedure and noise abatement activities has been given to more than 20 airlines around the world, and discussions with the U. S. Air Transport Association have been held on seven different occasions. An all-day symposium on subjects that included discussion of cutback procedures was held in Australia in 1974. I am well aware that noise reduction through operational procedures has piloting implications viewed as disadvantageous in some areas. I am going to save my comments on that subject to the end of this address, but I recognize that some of these objections are quite valid.

Large savings of fuel in the terminal areas can be accomplished by precision area navigation; fuel can be conserved with advanced avionics in an airplane operating under strategic control. The required avionics include precision area navigation equipment and improved displays and instruments to allow the pilot to make a direct pathcurved, descending, decelerating-approach to the runway, with a close-up transition to a microwave landing system for guidance on to touchdown. When this direct path is compared to the other approach where the airplane is manoeuvered in an outer direct course intercept area for coarse speed/position control and in an inner DICE area for fine speed/position control, the resulting fuel saved for a 747 is approximately 1000 pounds. Using these data and analyzing an airport like Los Angeles International (LAX) where 500 approaches per day are typical, and assuming 80 of these flights are 747's or DC-10's and the remaining

ATC System for Strategic Control

CENTRAL DIGITAL

f.

------------------------D~A-T~ESSO--R____~ ~ SURVEILLANCE

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•

DIGITAL DATA LINK

t

AIR TRAFFIC

.c:J MANAGEMENT Figure 4

Busy-Hour Delay Comparison --IFR Operations LOS ANGELES INTERNATIONAL AIRPORT

AVERAGE BUSV·HOUR

DELAY !MINUTES)

110 (1.2X1972)

129 (1.4X1972l

147 (1.8X1972)

166 (1.8X1972l

184 l2X1972l

BUSV·HOUR TRAFFIC LEVEL (NUMBER OF OPERATIONS)

Figure 5

Noise Reduction Via Operating Procedures, Approach Example 4 ALTITUDE (1,000 FT)

2

TRANSITION TO 3° GLIDE SLOPE

t

t

0 120 110 EFFECTIVE 100 PERCEIVED NOISE LEVEL, 90 EPNdB 80 700

3 4 6 2 5 7 DISTANCE FROM THRESHOLD (NMI)

8

Figure 6

21

420 flights are other type aircraft that use one-half the fuel

consumption, the total fuel saved per day just at LAX is approximately 300,000 pounds.

Advanced Guidance and Control System (AGCS) Boeing has worked on an Advanced Guidance and Control System since 1969. The present avionics have grown to the stage where the resulting number of black boxes required is becoming costly and complex. The large number of boxes is required because of increased performance requirements and mission reliability (redundancy for a failoperational CAT Ill landing system). In the future there will be new requirements - noise abatement operations, 30/40 path control, precision terminal area navigation, microwave landing system, and CAT 1118 weather minima operations.

A need exists to re-examine the total system - see what can be logically integrated, and provide a flexible configuration, at less cost. The development of use of digital systems makes this approach practical. The research work at Boeing is known as AGCS - Advanced Guidance and Control System. It is anticipated that with this integrated/digital systems approach, the cost will also be reduced. The goal is to combine logical functions/systems and reduce the number of black boxes as well as simplify the interface requirements. Careful judgment has to be applied and factors such as flight critical versus noncritical, dispatch requirements, certification, self-test capability, maintainability and cost have to be considered.

A "today's system", redundant-fail operational landing system cost is three times that of existing dual passive systems, and the U. S. SST, if we had continued, would have been even higher. The integrated/digital system should get us back in the "ball park" of the existing dual fail-passive systems. Fortunately at Boeing, we have had Government contracts besides our own company IR & 0 money to support this AGCS work. In a NASA 737 airplane, we have installed an advanced digital guidance and control system including cathode ray tube (CRT) displays. Most of the advanced equipment was funded by a FAA contract.

The major equipment subcontractors were General Electric and Litton. NASA and the FAA have a joint program and Ian to continue using this research airplane and the adP . t . t vanced systems installed to conduc~ expenmen s m erminal area operations, such as noise abatement approaches, CAT Ill autolandings, precision 30/40 are~ navigaanalysis. These t .ion, erew/display interface and workload f . . d experiments will lead to the definition o av1~nic an aerodynamic features that enhance operations m future highdensity terminal areas. are: Th e f un ctions performed by the AGCSf system t• f designated flight critical or noncritical as a. unc ion o . the short-term effect that may result from a f~1lure. :unct1ons such as autoland and stability augmentation, wh1c~ could hort-term flight safety, are designated adverse Iy affect S . . flight critical and are triple redundant, while functions such as map data generation and airspeed/select/hold are designated as noncritical and are dual redundant. I~ shoul~ be noted that a navigational capability through ~O 1s provided.

In addition, curved paths of selectabl~ radius ~o conn~ct geographically defined points. are provided. A fa1l-operat~o­ nal autoland system is provided (except for servos) including flightpath angle control wheel steering.

The airplane can be flown ~anually, or the flight can be completely automatic from hftoff to touchdown/rollout.

22

The navigation and guidance computer always operates from a "best" combination of INS, VOR/DME and air data information sources. This is true even during taxi before takeoff. The accuracy of these sources is typically not good enough to support an automatic takeoff without risk of running off the runway. However, automatic 20, 30 or 40 control can be engaged immediately following liftoff.

NASA's Research Support Flight System aircraft has been modified to incorporate an aft flight deck (AFD) - a second cockpit from which a two-man crew can fly the airplane. The primary flight controls consist of conventional rudder pedals and panel-mounted controllers (Brolly handles) for roll and pitch control. The system is completely fly-by-wire. The AFO crew can have complete command and control of the aircraft from takeoff brake release through landing rollout with no natural vision whatever.

The airplane has been flown across the U. s. in this condition. The forward flight deck (FFD) remains the same (standard installation) and fulfills the requirement for a safety pilot and backup instruments. This arrangement permits a high degree of flexibility and allows two-man crew experiments not possible in the forward flight deck. The AFO is equipped with operating instruments and indicators, and functional controls to provide an appropriate workload for the two-man crew. A nose-mounted forward-looking low light level television camera presents a view of the outside world on the CRT display - an electronic attitude director indicator (EADI).

The EADI is the pilot's primary instrument for pitch and roll attitude information. Symbols for velocity vector, flightpath acceleration, vertical guidance, speed error and thrust com.mand~ are integrated into the EAOI display format.

Radio altitude is displayed in digital format starting at 2500 feet, and a symbol indicating raw ILS data appears during final approach. Command bars are included for flight director modes.

A large center (CRT) constitutes the electronic horizon-

t~I situ~tion indicator (EHSI). This instrument provides the

pil?t with a display of airplane position relative to waypomts and geographic points such as airfields VORTAC's and ' mountains. These, and other navigational data, may be added or deleted by the pilot. The desired horizontal flightpath is displayed by a solid line connecting the waypoints.

A dashed curved trend vector line is provided and depicts the effect of present turn rate and speed. A time box indicat~s desired path position along the track during 40 navigation. A digital heading is indicated at the top of the scope. The EHSI modes include either track-up or north-UP map. ~ small bottom CRT/keyboard is the navigation con~rol display unit (NCDU). It is the primary man/machine ~nterface with the system. Only alphanumeric information IS d; I .sp ayed. The mode control/select panel is in the canter of the glare shield. f

During the development of this system, I had the unorgettable experience of sitting between the two pilots wh'I1e we executed a completely automated flight between Bo. F" emg ield and Everett, a field about 25 miles to the north. The course was circuitous because of ATC procedures i~ the area. It was totally automatic; the situation was entirely monitorable from the cockpit.

W~ have flown for only 77 hours, making 166 landings. which 77 were automatic. The accuracies obtained are m the "ball par k" f or those required for future precision · t'ion (40) at congested terminals where strategic are a nav1ga

?f

control is implemented to increase capacity and reduce

delays. Much more information is needed in this area, and research is planned by NASA/FAA. Out of this program has developed, of course, a series of advanced flight deck concepts. Some are applicable to either current airplanes or future ones. A typical modern transport airplane may have as many as 14 or more devices that function as computers. Often, displays connected to computers add warning systems and duplicate information, resulting in a more complicated cockpit rather than the desired workload reduction. In addition, the flightcrew may need two procedures - one when the computer system is operating and a second when the computer is inoperative.

The time has come when many of these computers can be combined into basic systems that provide the necessary information to the flightcrew for safe efficient flight information but do not overwhelm them with non-essential information. I recognize that this is a highly provocative subject. That's why I have led into it so gradually.

Pilot Implications Current trends in commercial flight decks include greater emphasis of automatic flight control and automatic aircraft system management. The role of the pilot is rapidly changing from a manual flight controller to that of a manager, mode selector and safety monitor.

Without question, the automatic systems. once certified, improve flight safety. Long duration flight pilot fatigue effects are reduced by the consistent equipment performance. Granted, more reliance on automatic systems could tend to degrade basic flying control skills not often used.

Automation has already reached the point, however, that the nature of most failures are so "graceful" that even now the pilot stays on some level of automatics even with routine failures. The role of the pilot is changing.

Airlines are placing greater emphasis on use and sophistication of flight simulation equipment. Because of the high cost of airplane flight time, sophisticated flight simulators are very cost effective for training purposes, and the trend is to allow substitution of these devices for actual flight time even in initial qualification and flight checks. Because of the availabilty of these simulators, even greater training value is achievable through quality of simulation and capability of practicing a wide variety of very realistic emergencies. Through this means, any degradation in actual flying skills caused by reliance on automatic systems is outweighed by the significant improvement in ability to respond by greater exposure training in quality flight simulation.

Basic pilot skills cannot be ignored. Airlines must evaluate their training and facilities to ensure that they do a good job in their simulation. Many training operators. including Boeing, are developing excellent training facilities on which block time and training support can be purchased. Operators must ensure that they are not caught in the over-cost-conscious squeeze and ignore the change of emphasis in the use of quality training programs and equipment in fulfulling regulatory refresher training. ff this is properly done, overall skills will not degrade, and ability to handle the variety of emergencies will improve.

Now we come to another provocative subject - that of how many men should be in the cockpit. We all know without defining a basic number that the use of more crew members to reduce the workload is partially self-defeating, since each additional crew member requires co-ordination

with the already existing crew members, thereby increasing the total cockpit workload and adding to the problem of information dissemination and possible confusion or misunderstanding. We at Boeing have, of course, had experience in the design of both two-man and three-man crew aircraft and, of course, before INS we had a great deal of experience with four-man aircraft too.

The question of two or three men becomes significant, as you know, from an economic standpoint. I am not recommending that you try operating any of today's large airplanes with two men. I don't believe the choice of two or three men has much to do with number of engines or aircraft size. But it has a great deal to do with the fundamental design and with the systems involved. A system designed to be compatible with a two-man crew must require no crew action on any initial failure. It must require no instantaneous crew action following critical failures. It must have highly reliable computers to provide data for management decisions - for example, fuel status, flight schedule status, flightpath optimization, maintenance status storage, etc. It must have improved displays, not necessarily the pretty pictorial ones we have described, but ones equal to them. In short, it must be designed as an integrated two-man crew aircraft. Let us not forget the position taken by highly experienced personnel in our regulatory agencies. They have observed that in such a cockpit, the third man can actually decrease safety rather than increasing it. By the way, the use of two men does not mean stagnation in the demand for pilots.

Conclusion Let me conclude by predicting that growth in commercial aviation will continue. Along with it will be a more economically oriented transportation system. This economic orientation, however, will not prevent the development and widespread use of new Air Traffic Control systems.

In fact, the development will require them. The price of fuel will have a profound effect on the future. It will influence aircraft design, modification of aircraft now in use, and future demands for precision navigation, both enroute and in the terminal areas. We must accomplish all of this economically in the face of continued inflation. We must accomplish it with an improving safety record, not a deteriorating one. The aircraft can be navigated in a fuel saving manner. The crew complement can at some future time be reduced. Pilot proficiency must be maintained. While the computerization I have spoken of tends to highlight this as a problem, instead of fighting automation we should outline requirements for maintenance of proficiency within the automated system. Pilots and air traffic controllers should challenge themselves to develop criteria wherein they can work more efficiently.

The history of the air transportation industry has been one of change, and change is not necessarily a comfortable environment. However, pilots and controllers would not have selected their profession unless they wanted the challenge of operating within a changing system - unless they wanted the euphoria that comes from knowing that they have command of something, and that they are .a leader of it. I would charge you to expand your leadership horizon from the local problems of the current cockpits and radar screens to the larger problems of the air transportation industry, and the long-term viability of that industry. I know if you do this you will succeed.

23

Some Effects of SST and General Aviation Traffic on Controller Capacity~

by V. David Hopkin

Both SST Operations and General Aviation traffic have lmpllcatlons for controller capacity, which are expressed preferably in terms of the amount of work for the controller rather than In terms of the traffic handling capacity of the system. It can be deduced that controller capacity Is affected by Increased work deriving from the greater unfamlllarlty and less predictable behaviour of SST and General Aviation traffic. In the case of SST aircraft, much of this unfamlllarlty will dissipate with greater experience, and some of the extra workload will therefore be transient. Ultimately an experlen· ced controller, knowing how predictable SST aircraft have proved to be In their behaviour, wlll learn and follow appropriate standard strategies. In the case of General Aviation traffic, patterns of traffic behaviour will remain lntrlnslcally less predictable, and less possible to learn, so that some additional workload will therefore persist. General Aviation aircraft are more variable than commercial flights In the competence of pilots, In their famlllarlty with ATC procedures and instructions, In the navigational aids Installed In the aircraft, and In the controller's knowledge of the performance of each aircraft type. As a result, General Aviation traffic will continue to demand proportionately more attention, time and Instructions from the controller.

Introduction The capacity of an air traffic control (ATC) system fers to the amount of traffic it can handle, commonly re h . expressed by a number of airc~aft per our. Quest1o~s about controller capacity often imply that an answer m similar terms is expected and can be stated, but it is bet~er to think of controller capacity as the amount of work which all safety th e controller can do while continuing to meet d. . standards, to follow orthodox procedures an . instructions, and to achieve expected standards of professional competence. It is important to distinguish b~tween norm~I capa'ty h'ch can if necessary be maintained all the time the Cl , W I • h' h b controller is working, and peak capa~1ty .w 1c can e sustained only for a much short~r-: pe~1od 1~ response to mands This d1stinct1on directly affects urgent syst e m de · . . for the controller, but also has 1mpl1Work the amoun t o f . . · f ystem management and organisation. For cations or s . example, a controller working at norma~ ~a~ac1~ should have no difficulty at the end of his watc in an mg over his control task to an incoming controll~r. It may be much 'ff' It r even impossible, for him to do so when more d1 1cu , o working at peak capacity. examining the broad effects of SST For the purpos es Of . aircraft and of General Aviation traffic on the ':"or~ of the controller, it is presumed that controll~r .capacity as ~ua~. ble and constant. This 1s an over-s1mph. titat1ve, measura . . t' I for the statement of general trends and f1cat1on, essen 1a . . . b t potentially misleading because all the principles, u . t b ff d influences on controller capacity canno e quan I ie use they are not the same for every exactly an d b e Ca controller.

Effects common to Both SST and General Aviation Traffic

in their flight profiles, as with the SST, or when aircraft may be less adequately equipped with navigation aids, as with some General Aviation. The behaviour of individual aircraft may become more difficult to predict, and information on the aircraft may be poorer in quantity and quality. As a result the controller has more decisions to make, more problems to solve, more R/T messages to receive and transmit, more flight strip amendments to make, more data to enter into or retrieve from the computer, and more co-ordination to do. All of this is more work.

It is work directly associated with SST and General Aviation.

In general, such traffic requires more work by the controller than does more conventional and familiar traffic. The more SST aircraft and the more General Aviation aircraft there are, the greater will be the increase in the work, although this relationship need not be a linear one.

Indirect Effects The indirect effects on controller capacity relate to some of the implications of controlling more aircraft, or a greater variety of aircraft types, or aircraft which impose tactical restrictions in handling them. In controlling relatively unfamiliar types of aircraft, the controller has less personal experience to draw on. With experience he gradually learns how consistent the climb-out profile of an SST is and how much variability may be expected. But he does not know this beforehand. He must therefore act on the assumption that there may be considerable variability and ensure substantial safety margins accordingly. He must also pay more continuous attention to the relatively unfamiliar SST aircraft in order to gain experience and learn how it normally behaves. In dealing with General Aviation pilots, who may fly relatively infrequently, the controller may have extra work caused by the pilots' unfamiliarity with procedures, with instructions, with the flight region, or

Direct Effects A

t

of SST operations or General Aviation may capacity both directl~ and indirectly. ff t stem from the additional traffic and from the . , D1rect e ec s · ty of traffic to be handled. The controllers great er vane . . . capacity is affected when aircraft are relatively inflexible

affec~~~~ scontroller's

24

•) Revised text of a paper presented at the Biannual Convention of the United Kingdom Guild of Air Traffic Control Officers, Bournemouth, 30 October - 2 November 1974. The two themes of the Convention were SST and General Aviation. The opinions expressed are those of the author, and not necessarily shared by any official body.

with equipment. Such factors demand more than the normal share of the controller's attention and of his time.

Further demands on the controller's attention and time may derive from greater uncertainty and reduced flexibility in solving any problems which arise. Solutions such as holding an SST aircraft at an intermediate level during its climb may be strongly discouraged. Solutions depending on height separations may not be recommended, for most General Aviation aircraft are not transponding height information. Non-standard tactical solutions may therefore be required of the controller in handling SST or General Aviation traffic, since some normal solutions have been curtailed. Because of its greater uncertainty, such traffic may impose more stress on him. The indirect effects on capacity therefore relate to the non-standard aspects of SST or General Aviation aircraft, to the comparative lack of experience in handling them, to the development of new and less flexible tactical control procedures which they may entail, to the disproportionate amount of attention which they demand, and to the extra stress which they create.

On the whole, the advent of SST or General Aviation aircraft adds to the work of the controller. If either his existing normal or existing peak capacity must not be exceeded, then the amount of traffic which he can handle would be reduced by the introduction of SST or General Aviation traffic. If his existing normal or peak capacity can be increased, then it must be increased in order to handle the SST and General Aviation traffic concurrently with existing traffic. On balance, the effects are greater than they would be if further relatively predictable and uniformly equipped subsonic aircraft replaced the SST or General Aviation aircraft.

Priorities of Traffic SST and General Aviation aircraft pose a further problem affecting the controller's capacity, although they pose it in different forms. Many of the air traffic control procedures for achieving the safe, orderly and expeditious flow of traffic imply that the ATC service must also be impartial and not favour unduly one category of user over another, except in the furtherance of safety. Nevertheless, neither SST traffic nor General Aviation traffic can always be treated in the same way as other air users. The controller must give each some special attention and perhaps some priority. If an aircraft climbing to become supersonic cannot readily be held at an intermediate level for the convenience of other traffic then in some ways it has priority over other traffic, and the controller may have a disproportionate amount of work to keep other traffic safely away from its flight path. If an aircraft has such poor navigation aids that information about its height is uncertain, then separation from it must be achieved laterally and longitudinally and not by height, and other aircraft in the vicinity may therefore receive a disproportionate number of ATC instructions. For different reasons aircraft which are going supersonic or aircraft which are ill-equipped may in practice be given some priority by the controller in the interests of maintaining safety. They may also, for the same reason or because of limitations in their capabilities, have some priority in aircraft holding stacks.

Although SST and General Aviation traffic have the above implications for controller capacity in common, each has further specific implications for controller capacity.

SST Operations and Controller Capacity Dependence on Operational Experience In the present state of knowledge, most of the potential effects of SST operations on controller capacity can be named, but the magnitude of these effects is a matter for informed judgement rather than based on experimental evidence. For example it can be stated that controller capacity is affected by the consistency with which aircraft follow a given flight profile for climbing and going supersonic. Current evidence on this consistency must be based on theoretical and simulated assessments and on expert advice, as distinct from extensive operational experience.

Therefore, how consistent the performance of operational aircraft will prove to be is not yet known exactly enough for all the effects on controller capacity to be specified in detail. The main practical effects on controller capacity relate to the SST when it is subsonic or in transition between subsonic and supersonic flying conditions while it is still at flight levels and in flight regions which also contain subsonic traffic.

Perceptual Judgements The maintenance of separation using the information on radar displays requires perceptual judgement on the part of the controller. In making these judgements with conventional aircraft the controller uses his experience of the consistency of aircraft performance, and of the characteristics and flight profiles of familiar aircraft types. Normally, for example, if aircraft are in level flight approaching a point where airways merge or intersect, separation may be maintained safely at the intersection point by using the controller's experience of the predictability and consistency of the traffic, of aircraft type and even of specific airlines.

This principle can be-•xtended to situations where aircraft are not cruising in level flight but are changing speeds in a predictable way, as where airways amalgamate into a single stream during descent. An orderly flow is achieved even where speed changes occur associated with the descent profile for a particular aircraft type. In amalgamating streams of aircraft the controller takes these predictable factors into account in sequencing aircraft in a single flow with a minimum of delays, instructions or inconvenience to each one.

Although these judgements are a basic source of decisions in ensuring a smooth flow of air traffic, they are not in fact a function which human beings can fulfil very successfully in purely visual terms. This remains true no matter how much training or experience people receive.

Basic human limitations in information processing limit the accuracy which can be achieved, and certain characteristic visual distortions may occur. Current manual systems allow for such human limitations in achieving safety, but one implication is that improvements in system efficiency might be achieved if machines could assist the man in these functions of perceptual judgement. To some extent this is acknowledged by developments such as automated conflict detection and resolution, where the machine can assess the relevant information more quickly, more accurately and more frequently than the man.

The comparable situation for SST aircraft demands much more elaborate perceptual judgements. Suppose that two departing SST aircraft are at low levels and subsonic

25

Ferranti simulators put years on your student ¡ controllers

Our ATC training simulators give controllers the experience they need to do their job - before they start doing it.

This is due to the detailed and comprehensive realism of Ferranti digital simulator systems.

The trainee controller's radar displays are identical with those used operationally, and simulated RT and intercom are provided. With this equipment the trainee learns how to cope with aircraft identification, separation, sequencing, the allocation of levels, routing, stacking, and other problems.

Ferranti have studied air traffic control in depth and have an understanding of current and future needs as realistic as the simulators themselves. We know the economic importance of

handling heavy air traffic with minimum delays.

It's hardly surprising therefore that Ferranti ATC simulators have been chosen for the largest and smallest requirements and are currently in service or on order for London Heathrow, Amsterdam Schiphol, Rome Ciampino, Copenhagen Kastrup, Taiwan Taipei, Sydney Australia, and at the College of Air Traffic Control at Hurn. And a F erranti simulator is used at the .CAA ATC Evaluation Unit for their real time traffic control studies.

Ferranti Limited, Digital Systems Division, Western Road, Bracknell, Berkshire, RG 12 IRA. Telephone: 0344 3232. Telex: 848117.

FERRANTI

The real thing in simulation

fr .

speeds on different routes which will intersect at a point during their climb. Suppose that both aircraft begin to climb at predesignated positions on their routes and that there is a small difference between the times at which each starts to climb. In judging, before either starts to climb, when each will reach the intersection point of the routes and whether there will then be adequate separation between them, the controller has to make perceptual judgements and extrapolations about accelerating aircraft which are at different speeds at any given time, probably accelerating at different rates, and with relative speed differences which change as a function of these accelerating rates.

Judgements of this kind are very difficult to make accurately. In making them, the consistency of aircraft behaviour is of vital importance. If aircraft on different routes begin climbing a few minutes apart, and climb from designated positions consistently following the same climbing profiles, these circumstances could themselves be sufficient to predict a safe, ample height separation between the two aircraft at the intersection point of their routes. The greater the possible deviations from the designated point for beginning the climb or from the climbing profile, the wider the safety margins have to be to ensure a safe separation at the intersection point.

On the other hand, experience may show that the aircraft behaviour is relatively predictable and consistent, that the limitations are imposed almost entirely by perceptual judgements, and that these limitations can to some extent be overcome by providing automated aids or by expressing future flight profiles in terms of times rather than treating them visually. The ability to express future aircraft behaviour as times required to complete various manoeuvres or transitions also implies consistency of performance.

However, if performance is sufficiently consistent for this to be done, the practical outcome may be simply to allow a certain separation to ensure safety at the intersection point and to check the behaviour of the aircraft from time to time to verify that it has not become unusual.

Provision and Use of Information The above points illustrate a feature of controller capacity which often goes unrecognised - the distinction between the provision of information to the controller and his ability to use it. In planning future systems and facilities it is possible, using techniques such as .task analysis and job description, to deduce the information which must be provided before the task could be done. It does not follow that because the relevant information is provided the task can be done. The information must be provided in a usable form. 'Usable' in this context means compatible with the nature of the task, since the controller may be provided with '.nformation which he can use but which takes so long f?r him to asse~ble .or interpret that he cannot spare the time to consult 1t. This kind of situation can arise with lists of tabular data under busy traffic conditions: the extra search tasks which accrue with increasing traffic become so time-consuming that sufficient time is no longer available to do them properly. A comparable situation arises when attempts are made to reduce controller workload by further sectorisation; at some stage, no further benefits are attained because of the additional handover and coordination involved or because small gains on the ground are more than offset by extra work in the cockpit.

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Depiction of SST Aircraft Because an SST aircraft may need special treatment or demand more attention than other traffic, the question arises whether an efficient ATC system should draw attention to SST aircraft under control, without distracting too much attention from other aircraft. Should SST aircraft be i~ some way differentiated by a visual coding on tabular displays or on radar displays? Would it ease the problem of controller capacity if a suitable coding of this kind were introduced? On the whole the potential benefits of design~ting SST aircraft by a separate coding on the controller's displays seem small. If the conditions arose to make it necessary, other more pressing display problems would ~lmost certainly be present. It would perhaps be warranted if the c~ntroller was working at near his full capacity most of th.e time. Under such circumstances, the benefits, though tangi~le, would be relatively small. Colour coding may effectively attract attention, but monochrome information may then be neglected, and relationships between coloured and monochrome information overlooked.

Automated Aids T~e introduction of SST aircraft has implications for certain o.f the automated aids in the system. The nature and quahty. of the predictions about the SST aircraft may mean that its. future flight path, particularly during climb and descent, is less certain than that of other aircraft. It may .be more d'ff' 1 1cu It to program aids such as automated conflict detection and resolution to function effectively for an S~T aircraft in potential conflict with other SST aircraft or. with normal traffic. Either numerous potential conflicts m'.ght be detected which did not in fact materialise or certain conflicts might be detected late or missed. The contr?ller may continue to control SST aircraft manually the comp ut er assistance . without . used .in controlling other traffic. Certain of the criteria and data on which predictions are based are different for SST traffic: the controller will n~ed som~ guidance on what differences there are in the criterta~bemg used with the SST aircraft if he is to respond., correct!~ to automated aids in relation to them, and particularly if he is expected to accept or override proposed a~tomated solutions to problems. All these factors require him to spend more time either on interpreting the automa~ed aid or on doing a task manually without automated assistance.

Complex Solutions to Problems t' The s ~1utions which may be adopted in resolving poten1a con 1cts affecting SST aircraft tend to be less flexible than those for normal traffic because of extra constraints, ~uch. as major disadvantages in interrupting an SST durinQ its chmb, or greater reluctance to stack an SST. A possible outcome is that solutions will tend to place actions initially on the non-SST traffic with which an SST is in potential conflict, rather than on the SST itself. These solutions maY require the formulation and Implementation of more elaborate avoidance procedures because of the greater uncertainty of the speed, position and height of the SST aircraft at the time when it may be in potential conflict. More time will be required by the controller to formulate and check the adequacy of these less standard solutions, and to implement them since more numerous R/T messages will probably be necessary to do so. However, the total extra work imposed on the controllers and the consequences for

1

11

their capacity are relatively small unless SST aircraft become numerous. As experience is gained the controller will adopt the strategies which are safest, most economical, and least disruptive of other traffic for ensuring that SST aircraft do not come into conflict with other air users. Since the strategies necessary to handle SST operations most efficiently may be different from those for other aircraft, the controller may need to learn to use them alongside other strategies employed in handling normal traffic.

In general, the problems which arise in relation to SST and which have direct implications for controller capacity appear to be almost wholly restricted initially to terminal areas and the climb and descent phases of the SST flight.

From the human factors point of view, the density of SST traffic, while supersonic, seems unlikely to lead to any particular problems for oceanic controllers, apart from those already encountered in similar form with normal traffic.

General Aviation Traffic and Controller Capacity Sources of Extra Work General Aviation traffic includes a great variety of aircraft, ranging from those equipped to standards of commercial airlines to those with minimum equipment. Experience, ability, and familiarity with air traffic control instructions and procedures are all much less uniform among Gene~al Aviation pilots than among commercial pilots. In handling General Aviation traffic, the individual controller cannot make the assumptions either about the aircraft equipment or about the experience of the pilot that he makes in controlling commercial aircraft. He may either have to spend time discovering information about these facto~s or a~sume in the interests of safety that the equipment is relatively poor and the pilot relatively inexperienced, and control the traffic accordingly. The controller may be somewhat reluctant to question a pilot about his flying experience or about the serviceable equipment in his aircraft, if he considers such matters are not properly the concern of operational ATC or if he cannot spare the time for such enquiries. The effects of General Aviation traffic on controller capacity derive from his greater uncertainty in handling it, either because the information which he has on the traffic is less complete and trustworthy, or because the General Aviation traffic is on the whole less constrained in its behaviour and therefore less predictable.

Several factors make the handling of General Aviation traffic less flexible. Some refer to attributes of the aircraft, such as a smaller range of possible altitudes or cruising speeds. Others refer to differences between General Aviation and other aircraft in their normal flight conditions.

For example, General Aviation traffic may be slower and thus impose considerable workload in maintaining minimum separation standards while normal traffic is overtaking it.

Further physical factors imply that the normal separation standards betweeen aircraft may have to be increased for General Aviation traffic. These may become particularly noticeable during the approach and landing phase where the approach speed of General Aviation traffic may be slower, its landing speed slower and its movement along the runway not in unison with other aircraft traffic. In addition, it may be necessary to increase longitudinal separation because of the greater vulnerability of lighter aircraft to vortices from larger aircraft. All these factors mean that

the General Aviation traffic requires, in some senses, nonstandard treatment. Non-standard treatment in turn implies greater workload and more demands on the controller's capacity.

Some of this extra work derives from the variety of General Aviation traffic: numerous aircraft types with different characteristics may be introduced, and from time to time the controller may be dealing with an aircraft of a type which he rarely encounters. His knowledge of its normal flying characteristics, its cruising speeds, its climbing and descent profiles, and its manoeuvrability may be less comprehensive than that for most of the other aircraft which he controls. The behaviour of such an aircraft is less predictable to him; it demands more frequent monitoring and more of his attention, and hence affects his capacity.

Compatibility with Automated Aids Problems occur in matching many of the current and forthcoming developments in air traffic control with the needs of General Aviation traffic. In an environment where transponded height and identity information may be displayed as labels on a scondary radar display, there will be a considerable transition period when some aircraft are fitted with this facility and others are not. A considerable proportion of controlled traffic has to be transponding data automatically before the benefits from this aid outweigh the extra work involved in collating visual transponded height information and verbal R/T height information about different aircraft under control at the same time. Some General Aviation aircraft may well be the last to be equipped to transpond height information. For them, it may still be necessary to obtain height information verbally, write it on fl:ght strips, and incorporate it via keyboards onto tabular displays for a considerable period after this is done automatically for most other aircraft. The work involved is not simply that associated with the extra manual tasks and R/T, but is also that required in collating information in two different sense modalities, that is either visually or verbally, and in converting the verbal information into visual form to make it compatible and easily used with automatically transponded, visually displayed data.

The minimum required airborne equipment is a matter for legislation. Probably a situation will always exist where t.he expenditure which can be justified for commercial airlines can never be justified for certain categories of General Aviation traffic. Therefore there will probably always be differences between them in the quantity and quality

29

of the ATC information which they send and the ways in which they transmit it. This is economically sensible, but as a result the controller has to collate and compile information which otherwise would be assembled automatically for him. Most of the developments which can be foreseen, including for example area navigation and flow control, would be expected to encounter problems of this kind at some stage. They are not problems which have no solution, but the practical solutions give the controller extra work to do. This is an inevitable concomitant of conditions under which automated assistance can be utilised for some but not all of the aircraft in the system.

Further Demands for ATC

dictable and hence demand more attention. With increased familiarity the aircraft may become more predictable. With SST traffic, factors such as how consistently individual aircraft will begin a climb at a designated point or how consistently they will follow given climbing profiles are not yet known with sufficient certainty to determine how familiar and predictable they will become and therefore how far they will reduce the controller's capacity. No matter how consistent they are, the extra work attributable to their different flight profiles and speeds will remain.

General Aviation aircraft in principle allow less adaption than SST aircraft to the problems which they pose, because of the great variety of aircraft within General Aviation.

Some improvement may be expected from increased familiarity with General Aviation traffic but certain aircraft are likely to remain relatively unpredictable in their behaviour because of inadequate facilities installed, inexperience of the pilot, unfamiliarity with the routes, or rarity of aircraft type. Extra help will therefore be needed from the controller under circumstances where all navigation aids may not be available.

A further effect on controller capacity may be that, as the amount of General Aviation traffic increases, more requests are received for an air traffic control service. This would normally be on an advisory basis but if traffic became very dense it might become necessary to make it mandatory in the interests of safety. If more aircraft require Because the information about SST and General Aviaan ATC service, this would add to the workload of the controllers. Workload would also be increased by greater tion traffic may for different reasons appear less precise uncertainty among some of those requesting an ATC serand predictable there will be some tendency to steer other vice. The form of this uncertainty could range from pilots traffic away from these categories of traffic. The main requesting assistance because they were lost, through restraints on capacity depend on the increased time and pilots requiring verification of their position and advised attention which the controller must devote to SST or Generoutings, to pilots asking for detailed instructions when ral Aviation traffic. This takes the form of numerous more approaching an airfield with which they were totally unspecific tasks: additional Rfr messages, more frequent familiar. In all these tasks extra work would be entailed, checking of current positions and states of the aircraft the not only because of the additional traffic requiring an ATC i~troduction and maintenance of larger separations, ~ddi­ service and the more elaborate service sometimes needed, t1onal co-ordination and liaison loads, extra collation of but also because of limitations in the means by which that manual and automated information, the learning and use service could be provided, related for example to limitaof ne~ procedures based on the different profiles and tions in the experience of the pilots or in the facilities inhandling characteristics of the aircraft, and the incompletestalled in the aircraft. The size of the problem would ness of the information on certain displays such as secondepend partly on the amount of General Aviation traffic. dary radar displays because not all aircraft are fitted with The problem is unlikely to overstretch the air traffic control the same transponding facilities. Additional restraints on system seriously for long. If it ever showed signs of doing th_e controller's capacity may be Introduced, associated so, it would become necessary to restore the controller's with reconciling future automated innovations with General Aviation traffic. workload to a reasonable level by such means as making the installation of certain navigational aids mandatory in From the above it might be deduced that the extra all aircraft requiring an air traffic control service, or perwork associated with SST and General Aviation traffic haps segregating certain kinds of General Aviation traffic. could. reduce the controller's capacity so much as to make Therefore although General Aviation can be expected to ATC impractical. This is not envisaged to be the case. add to the controller's work and, if he is busy, to reduce Some problems will be overcome by the adaptability of the his capacity for handling other aircraft traffic, it is not encontroller, by learning, and by experience. Others may be visaged that in the long term its effects would be serious ov~rcome by the introduction of restrictions to ensure the enough to jeopardise the ATC service, since effective steps maintenance of safety. Such restrictions are most likely to to forestall such a situation would have to be taken long affect routes, destinations, and mandatory airborne equipbefore it became serious. For any given number of aircraft, ment for providing an ATC service. If the proportion of if they are all commercial flights the work for the controller General Aviation traffic becomes large, then special ATC is less than if they are a mixture of commercial aircraft and procedures may have to be evolved to handle •t as a f • I , General Aviation traffic. means o ensuring safety and of making workload tolerable.

Conclusions Both SST and General Aviation aircraft have effects on controller capacity. On the whole, more capacity is required to handle an SST or General Aviation aircraft than a normal commercial aircraft. The main reason is simply that such aircraft are different from normal commercial traffic.

Therefore they are less easy to fit in to normal traffic patterns. Because they are different, controllers have less experience of them. Therefore, initially they seem less pre-

30

In dealing with controller capacity the behavioural aspects have been emphasised, but the indirect effects. related for example to stress, should not be forgotten becaus~ ~hese too have measurable effects on capacitY· Res~nct1ons on controller capacity may be induced directlY by increased workload, or indirectly by the stress associated with increased workload. The reasons for strivin9 to ensure that normal capacity is seldom exceeded and peak capacity rarely approached refer to stress as well as to workload, to the well-being of the man as well as to the efficiency of the system.

Finally, there is a positive side to these problems of controller capacity. If a controller is asked what aspect of his job gives him greatest satisfaction, he usually cites some incident which used his professional skills to the full, which imposed stress on him, and which presented him with a challenge he successfully met. This is one of the main sources of job satisfaction: the ability to develop skills coupled with the opportunity to use them. SST traffic, and especially General Aviation traffic, introduce greater unpredictability into aircraft behaviour, and may render some aspects of automation incomplete. In solving the consequent problems, reliance is placed on the flexibility, skills and experience of the man, and on his ability to innovate and adapt. Accordingly, with the increased advent of SST and General Aviation traffic more opportunities will arise for controllers to achieve job satisfaction, by exercising their skills to maintain the high standards of the profession of air traffic control.

Comments on Air Traffic Control

by Aviation Spokesmen across the World E. Bradshaw, U. K. Guild IFATCA Director, on the value of membership of IFATCA:

There have been instances of members questioning the value of our membership of IFATCA, and 1 have no doubts that this subject will again be raised in the future particularly by our newer members. I am ever consciou~ that the membership should not only be kept informed of our IFATCA activities but made aware of the benefits that we, as a Guild, derive from membership of the Federation.

We joined IFATCA in 1962 because we considered that the basic aims and objects were the same as our own constitution. The Federation was only founded the previous year by 12 Associations; though the concept was world wide, at this stage membership was European. We thought then, together with whom we joined that the U.K. had a great deal to offer in professional and technical knowhow.

Similarly we could learn a great deal from our colleagues abroad. This has not changed today - now there are 39 Associations spread across the world, and whilst our input is greater, surely our "benefits" from the exchange of technical info and professional ideals has also greatly increased.

Our involvement has been total and in many ways we have influenced the course of IFATCA - Constitutionally, Admin and Finance, and I think most of all in the Technical field. This is surely shown in the way that member associations ask us to lead the Federation on technical affairs through our continued leadership in S.C. I. Additionally much of the technical effort has been by our own members, a very fine effort too and acknowledged as such by the world's associations.

If we consider the objects of the Guild, then the benefits of our continued membership are clear: a) the exchange of Technical info, and advice from member associations together with the expertise of Corporate Members both of the Guild and IFATCA, and b) continued exchange of info on Professional and Admin affairs on an ever increasing scale as more Associations join IFATCA. Unfortunately the majority of controllers are unable to read the IFATCA Conference papers and reports though this

should at least be possible at the major units. At each Conference I have attended I have collected a complete set of papers; these are currently on view at the Scottish ATCC. Sufficient papers are available at Conference for each delegate to do this and there would be no expense involved.

If one gives thought, the benefits of IFATCA membership are numerous and to the advantage of all U.K. ATCOs.

William Horn, Jr., Manager, Airspace/Air Traffic Control Services, U.S. National Business Aircraft Association, on the subject of Lost Flight Plans in the Automated System: Since I have been with NBAA, the lost flight plan has been one of the major irritants. How do you answer the pilot who writes and tells you that he has lost eleven flight plans in one week? Or the pilot who calls you on the phone and says, "I file Racine-LaGuardia-Racine. Twice in a row LaGuardia has no flight plan. I had to sit there while 8 airplanes taXied out and took off, my boss thinks I am an idiot."

We are quite concerned about the lost flight plan situation. We know the number of general aviation flights are going to increase tremendously over the years. We will be flying more and more random, short duration flights, and we will also increase to a great extent the practice of early filing at one location of 6 or 8 flight plans for one day's operation by one aircraft. As our senior business managers become more and more aware of the capabilities of their time machines and realize that the daily aircraft utilization rates can be increased substantially, we are going to find that they will allow more and more of the company executives to utilize these aircraft. This places increased pressure on aviation managers to insure that they are not delayed whenever they need to depart from an airport.

When we talk about automation we visualize black box to black box operation, with the human being the observer and the corrector if anything goes wrong. I will not go into the flight plan filing procedure in detail but will highlight the many ways people are interjected between the black boxes in this process.

At least three men can physically handle your flight plan at the FSS facility; a minimum of two in the Tower; at least two in the RAPCON; and at an ARTCC that receives a clearance from an FSS that is not one of their assigned facilities two more people could be involved. Now this is the basic flight plan. If you have any time involved between filing and departure or if you have filed a multiple flight plan, you have personnel jo~ rotation in each facility on each shift, and you have shift changes. So you see, it is fairly accurate to say that in some cases as many as twelve people have a chance at doing something to your clearance.

In addition, computers are not operating during the evening hours, say from 10:30 p. m. until 6:00 a. m.; thus the recommendation, "It's best to file when the computer is operating." If you file at the late hours, you are back to a manual operation. But if an FSS receives a number of flight plans at 4 or 5 in the morning that are of the multiple type with proposed take-off times from 6:00 a. m. until 4:00 p. m .. we now have a people decision - do I file all the flight plans manually, or do I file the 6:00 a. m. and the 8:00 a. m. flights and hold the others until the computer starts up?

If I decide to file them all manually, does the man at the Center take action on them all or does he work only

31

the early morning departures and process the rest when the computer starts? Multiply these decisions by the number of times they must be made throughout the country and you have a beautiful lost flight plan potential, and where is your automated system?

Now add the computer. When it gliches, flops, or stumbles, you have a "Chinese fire drill" when you attempt to manually pick up all the clearances that the computer did not process.

All in all we feel that this is probably the weakest link in the entire automated system, and we honestly have not been able to find out how the FAA is going to resolve the problem. Therefore, we think that priority attention should be given to the subject.

Michael v. Huck, Director, Air Traffic Control Dept., Policy and Technical Planning Division, U.S. Aircraft Owners and Pilots Association, on the Importance of the Low Altitude En Route System: Things are changing in the world of aviation, and if air traffic control is going to keep up with the times, it will have to change too.

The JFR system was heavily dominated by the airlines in the past, but general aviation use of the system has grown by leaps and bounds. In a few years, the little airplanes will actually dominate the system in the U.S. Unfortunately, these little planes don't go just from New York to Miami and from Los Angeles to Chicago. They go everywhere. And to handle this different kind of traffic, new procedures must be implemented.

The first thing that needs to be changed is the delegation of airspace to the terminal areas. Today, terminar areas control altitudes up to ten thousand feet or more.

Unfortunately, most general aviation aircraft cruise most efficiently at altitudes below ten thousand feet. This creates problems when an en route light aircraft passes, or rather attempts to pass through some one's terminal airspace.

In theory there is no problem. The Center hands you off to Approach Control, and you merrily sail through the area.

In practice it is another story! In some cases the controller is simply too busy to do the necessary coordination.

In most cases he just doesn't want to be bothered. The terminal area becomes a giant roadblock in the sky, and the only remedy is to climb to an altitude that is inefficient or detour around the area, either of which costs time and money.

The low altitude en route system is showing the highest growth rate in operations of the entire aviation system. It seems vital that someone should do an analysis of where the system is growing and what is needed to handle the growth that can be projected in the near term future. Certainly, a change in emphasis will be necessary and the system is less likely to grind to a halt if that change takes place on a timely basis.

The most important problem is changing the character of the service with the changing composite of traffic. If the system can not be modified to handle more efficiently the large increase in low altitude IFR en route operations that is coming, it will have failed miserably.

Brief News Items Cont. from page 12

Gander to keep Pace with Increasing Traffic Movements A$ 3,638,200 Air Traffic Control Operations Building ~ill be constructed at Gander, Newfoundl~nd, t~ cope ~1th increasing air traffic in the North Atlantic Region. Funding f the structure and equipment will be spread over the n:xt three years, with completion scheduled in 1978.

Th e 53 OOO square foot structure will house the Area 'I . m1 es C on t ro I centre responsible for some 1,142,000. square of international airspace in the North Atlantic Reg!on, the responsibility for which was assigned to ~anada in 19.46.

The facility will also be capable of grow1~g and coping with the expected 65 per cent increase during the .next 10 years in IFR traffic movements over the North Atlantic route and through the Gander Domestic erea.

I

countries have attended courses, and States in this category who have sent participants and/or speakers to courses and seminars include Austria, Barbados Denmark.

Italy.' Nigeria, Norway, Portugal, Rhodesia, s~udi-Arabia, Spam, Sweden, Switzerland, to name but some.

In addit~o~ to specialists from various quarters, the U.S. Federal ~v1at1on Administration is continuing to send representatives to the lnstitute's annual seminar which is held in late summer or early autumn.

Hundreds of students from Europe and elsewhere have so far benefitted from the courses the Institute offers.

These students have all been fired by the same team spirit that ma~es for success and worthwhile achievement. They. a~d the'.r successors, will be the guardians of the safety of air traffic - the constant objective of Eurocontrol.

U.S. Controllers concerned over Lack of Computer Back-ups with A .ir t r affic controllers at major airports equipped · I the Sperry-Univac ARTS-3 automated radar ter?1ma system are becoming increasingly dependent on their new automation aid, prompting increased controller. concern over consequences if the lone Univac computer th e po t en rar 1 h d'. at each airport should fail during weat er con 1t1ons requiring instrument flight. Since 1973, FAA h~s had the funds to purchase a standby computer for ma1or ARTS-3 airports, but the agency has not ~et ~lac:d an order f~r additional computers. If it does, 1t will still ha~e to wait 12-18 months for the backup systems to be delivered and installed.

32

(Airline Observer)

• • . Ah Correction: Inaccuracies In our May 1975 Issue

whi~ ~h~

;ush between make-up and printing due to a deadline 0 a be met In order to have the issue available for our S~and at the Paris Air Show, part of the final proof reading had to be 1 s . Pphed, resul.ting in a few inaccuracies which - we trust - readers 11 w1 ave easily spotted · Th e article · · 1 L in the series on lnternat1ona f aw ~~s no. 6• not no. 7 as Inadvertently given. The Aircat System ro'.11 . omson T-VT is, of course, a New System, not a News system. while '" the report from our Australian Association, the Association has warned (not was warned) that compulsory staff transfers to Darwin would not be accepted. We regret the inaccuracies.

Report From The 1975 Melbourne Conference IFATCA - 75 MTW AMÂŤJU.:'

~

C.:- THE rNTERNATIONAl.. FEDERATION

OF OSI mAFRC CONTAOU..ERS' ASSOClATIONS

The Australian Minister of Transport, the Honourable C. K. Jones, opens the Conference.

The Federation's 14th Annual Conference In the Melbourne Hiiton was opened by the Australian Minister of Transport, The Honourable C. K. Jones, M. P., and was attended by 24 Member Associations, 13 Non-Member Countries, 8 Corporation Members and 12 International and National Corporations. Altogether, a record total of 493 participants were registered, making It IFATCA's largest Conference to date. During the Conference, 133 recommendations were passed to Final Plenary, also a new record. Sri Lanka, Slera 'Leone and the Eurocontrol Guild of Air Traffic Controllers were admitted as Member Associations, bringing IFATCA membership to 41 Associations. Mr. E. Bradshaw (U. K.) was elected Vice-President Administration In place of Mr. H. Guddat (Germany), who retired after 7 years of service In this capacity, while Mr. O. Jonsson (Iceland) was unanimously re-elected for a further term as Vice-President Technical.

The superb arrangements made by the Australian Memb~r Association led by Conference Organiser Ray Soden paid off handsomely and the busy work-programmes were completed without a hitch and within the time allocated.

Opening Ceremony In a special message of welcome to delegates on their arrival in Australia, the Transport Minister had sketched the role of th e Air T raffic Controller as being vital in today's world of aviat ion to the safe. orde rly and expedit:ous flow of air traffi c. It was a ro le demanding con ti nued ded 'cation, deep con centration and a high degree of alertness an d expertise. IFATCA had been actively involved in inte rn ational aviati on affai rs since its in ception in 1961 and had mad e important co ntri butions to the stream lining of ATC procedu res. The Minister had ended by point ing o ut that th e decisions delegates wou ld make at the Conference would, no dou bt, enh ance world aviatio n safety and the reputation of th e profess ion they represented.

At the Conference opening itself, the Minister said that his Govern ment co nsidered it quite on honour that the Federatio n had aband oned its traditional Northern Hemisphere meeting places to hold its 1975 Conference in Melbourne - the first held in the Southern Hemisphe re - and that the Govern ment was giving t he meeting its full support. As good Air T raffic Control was the bas is of any safe,

efficient airways system, it had been developed in Australia in parallel with the demands of aviation in that country, and t his ai m had been achieved and was reflected in the nat:on's international ly high aviation safety record. Australia was tremendously proud of that record and completely intolerant of any action which may jeopard ise it. Australia had been described by some overseas organisations as a " police state" when it came to aviation administration (Ed itor's note: even in " T he Controller" - see our editorial in the August 1974 issue.) T his cou ntry carried that label proudly. It was a recognition of an intense desire that aviat!o n operations in Australia should be, above all things . safe. Far fro m considering the remark an insult , it was regarded rather as a compliment. Because ATC is such a vital part of aviation, it must be able to match aviation 's rapidly changing and ever-increasing demands. It can never experience the luxury of dawdling. The current val ue of Austra lia's aviation facilities was $ 444 million and the annual operating costs of airways and systems $ 140 million , and the return for this outlay was shown in the nine mill ion passengers carried by t he natio n's domestic airlines (with a total popu lation of a little more than 13 mil 33

Committee "A" (Administration) with Mr. Ray Soden In the Chair, Mr. McCluskey as Vice-Chairman, and Mr. Papathomas as Sec retary.

l:on, that's not a bad reco rd.) But this w ou ld not have been achieved without a vast network of ai r-ground navigation facilities and co mmunication aids and by a highly efficient A ir Traffic Control system.

The Minister concluded by saying that he was impressed with the nature and scope of the items listed on the Conference Age nda, which would no doubt result in recommendations w hich would be brought to the attention of ICAO and other world aviatio n authorities. This year happened to be Internat ional Women 's Year, and with a number of women controllers e mployed in the ATC organisation, it was p leasing to see so many women at this Conference. Air Traffic Cont rol was dynamic work of g reat national and international importance and one which provided a n attractive ca reer for young men and women whose interests li e in aviation.

The President of IFATCA, Mr. J-D. Monin, in his opening address stressed that di stances and boundaries did not ex ist in the ATC w orld as th e professien was truly international. Our presence at Melbourne was owed to the fact that all of us we re engaged in one of the most tremendous adventures of t he Twentieth Century : the development of civil aviation. It had been said on many occasions that aviation was abolis hing frontiers between people and civilisations , but it cou ld never be overemphasised that civil aviat ion was the best means of comm unication and better understanding and t hus s hould be a bastion of peace among peop le. Th e Executive Board had mai ntained IFATCA's course on its t rue professional track and had refused to follow any politi cal heading. The President of the Australian Association , Mr. R. F. A lexander , welcomed the participating countries, observers and oth er organisations, and said that over the past 14 years , IFATCA Confe rences had initiated many technological advances in Air Traffic Contro l and in aviation in general. These Confe rences were vital in maintaining contacts between controller associatio ns - the spirit of co-o peration in dealing with the vario us problems associated w ith an efficient ATC syste m was essential in promoting our profession.

Another spea ker, at a lat er stage during the Conferen ce, was Mr. c . c. Halton, secretary to the Aust ralian Department of Tran sport, who mention ed the Federat ion 's close interest in the work of ICAO a nd the high reg ard in w hich the views of the Federation a re he ld in ICAO and by Contracti ng States.

34

Conference Committee Sessions And so the Conference went on its way, and delegates quickly settled down to days of intense work. A s usual, three Conference Committees were appoi nted to deal with the Administrative-, Technical- and Professional matters in hand. An official Conference Report will be produced instead of the June/July IFATCA Circular, and for that reason o nly a very brief o utline of the most important decisions taken follows. The Administrative Conference Committee, at the instigation of the U. s. delegat ion, supported by New Zealand, established a Wo rking Group consisting of a cross-section of large, medium and small Member Associations und er the auspices of IFATCA Treasurer Jean Gubelmann, and this Group will investigate the system and scales of subsc riptions to commence in 1977 in orde r to come up with a report to the 15th Annual Conference.

:h~ Executive Board was continuing its efforts towards achieving normal conditions in the Eastern Mediterranean A rea arou nd Cyprus, and the following resol ution was adopted: In the inte rest of Air Safety, IFATCA condemns any action which endangers the safety of Air Traffi c , the refo re the UNO and ICAO will be urged : 1.

!

0

restore ICAO standards and recommended practices in order to provide complete Air Traffi c Servi ces in the Eastern Mediterranean Area;

2· To restore the navigation and comm unicatio n facilities located at the Nicosia Internatio nal Airport.

It was decided to hold the 1976 Conference in Lyon (France) from the 26- 30th April, while the 1977 Conference was all ocated to Cyprus and the 1978 Conference to Denmark (provisionally) . In future, before a Member Association can be ~onfirmed as host for the Annual Conference, an underta~ing mu st be given that to their best knowledge and belref no delegates of Member Assoc iations will be barred from entering the host country for political reasons. relafrons wrth · IATA were c losely ex a. The . Federation's . mined .in. the lrght. of th · . e continued absence of complete

re~ogni.tron an.d lrmrted assistance from that Association whrch 1~ cau sing dissatisfaction amongst the cont rollers c~ ncern~ng the esteem which IATA has for ATC. IFATCA will again requ e~t . t.hat IATA demonstrate its t rue support fo r the respon s1b1lrty and integral part of the aviat ion co mmunity whi ch a controller ho lds in the ATC system.

Committee "B" (Technical) chaired

by Mr. Saker.

The President of the Civil Aviation Workers Union of the USSR, Mr. V. Zuev, being unable to participate in the Closing Ceremony, address~d a combined session of the three Conference Committees and expressed his Organisation's interest in the Federation, its desire for continuing co-operation with IFATCA, and the good wishes of the USSR Controllers to the Federation. Mr. Monin, in reply, expressed the hope that our USSR Colleagues would soon take their rightful place in the international controllers' community and take part in the work of IFATCA.

Technical Matters A large number of Working Papers were tabled and discussed by the Technical Conference Committee, such as one on the use of digital, computer processed, rad ar positional data for the radar separation of aircraft, which will be submitted to ICAO for consideration by 9th -ANC. Another Working Paper concerned Air Traffic Flow Management {the proposed introduction of National Flow Coordination Cells, the establishment of Airspace Utilisation Sections, etc.), also to be used as a basic for the preparation of an IFATCA Paper for 9th ANC. After considerable discussion involving delegates and Qantas and IFALPA observers, it was recommended that Member Associations take every opportunity to make airline operators aware of the routine delays inherent in over-scheduling, and encourage the formation of scheduling committees on which there is full participation by relevant aviation organisations.

In addition, the aviation world should be made aware that ATC cannot be responsible for delays incurred by indiscriminate scheduling of flights, and that at those ai rports already operating at or near capacity, some form of quota system must inevitably result. Other material to be prepared for 9th ANC concerns Flight Plans and ATS Messages; Secondary Surveillance Radar (including a brief that no action be initiated by !CAO towards the de-commissioning of mode B until IFATCA has had further opportunity to study the value of this mode to ATC); Air Reporting; Transition Altitude; Monitoring Devices in ATS Units ; Automated Interchange of A ir/ Ground Data; Linear Holding and Turbulent Wake.

Two Working Papers on the Simu ltaneous Use of Parallel Runways were discussed with a view to the establish-

ment of IFATCA policy. On the subject of Airborne Collision Avoidance Systems, a number of points were made by IFALPA indicating differences in their policy from several of the policy statement proposals included in the Paper prepared by IFATCA's Standing Committee I. It was recommended that IFATCA closely monitor the progress in the implementation of CAS through liaison with industry, Member Associations and other aviation groups with a view to the development of a detailed policy statement on CAS. Participation by delegates and observers representing pilot organisations and airline operators also took place when the application of linear holding techniques to aircraft other than SSTs were discussed. IFATCA recognises the potential benefits to be gained from adoption of the techniques known as Linear Holding, but is opposed to any implementation without provision of appropriate procedures, airspace organisation and ATC equipment. Regarding Turbulent Wake, IFATCA deplores the lack of standardisation of the ¡application of Wake Turbulen ce separations throughout the world. The highest priority should be afforded by ATC authorities and ICAO to the standardisation of procedures in the context of Wake Turbulence separat ions, and !CAO and Administrations should be urged to prevent, through adequate provis ions, Air Traffic Controllers being increasingly confronted with the danger of involvement in aircraft accidents attributed to wake turbulence, especially during the approach and departure phase.

Civil/ Military integration also featured on the agenda, and it was decided that, due to the great complexities that occur from separate development of civil and military ATC systems, further prolification of such systems would be viewed by IFATCA with grave apprehension. Further subjects discussed in cluded Automation in ATC, and the need for a new European Airways Plan. It was also recommended that the Fed eration fully support the desirability to set aside a specific International Aviation Communication Week to emphasise the already laudable sentiments of maxi mum professional liaison between pilots and controllers.

Professional Matters Working Papers examined by this Conference Committee inc luded : Medical Studies being carried out in

35

II IFATCA-75 1aT1-1

ANNUAL OF

CONFERENCE AIR

OF

THE INTERNATIONAL FEDERATION

T RAFFIC CONTROLLERS . ASSOCIATIONS

Some of the many Asian delegates who attended the Conference, together with colleagues from other corners of the globe.

France; the Legal Liabi lity of the Controller; Hijacki ng and the Controller; Legal Developments in Aviation; Potenti al Causes of Systems Errors - The Controller's Viewpoint; and other subjects.

Discussion of the Report of the IFATCA representative to the International Symposium on Practical Applications of Ergonomics (Bucharest, September 1974) resulted in the recommendatio n that IFATCA in future would be rep resented at simi lar occas ions in ord er to attract a world-wide attention as to the exist ing unsolved problems in ATC. David H opkin 's report on the 22n d International Congress of Aviation and Space Medicine (Beirut, October 1974) and the report by the IFATCA delegation at the 31st Congress of the Internat ional Trans port Wo rkers Fede ration (Stockholm, Aug ust 1974) were accepted , and IFATCA will try to act within the ITF through the air traffic contro ll er representation in the Ground Staff Com mittee of the ITF. Some of the other points dealt with were : the Study of Aviat ion Law as it affects the Contro lle r ; the Sponsoring and Supporting of th e passage of legislatio n and :egul~­ tions which wi ll increase and protect the safety of air navigation; the study of cau ses of in cidents, layout of r~ports, standardisatio n of invest igation procedures, qu esti on of publication of factua l findings of investig ation; .th~ Study of all legal matters concerni ng the safety of av1at1on and

· h t. s·1r Donald Anderson . Chairman of. QANTAS From left to ng .

Australian Airli nes. Mrs . T . H. Harri son and Mr. Jean-Dan ie l Manin .

President of IFATCA .

36

in particular hijacking and terrorist attacks on aircraft, airports and Air Traffic Control installations. IFATCA will ma:ntain contacts with Legal Departments of International and National Organisations with a view to introducing an International Convention limiting Controller Liability, and through individual Member Associations establish informal contacts with National Legislative bodies of Legal Departments in order to investigate the possibilities of limiting Co ntroller li ability. The Federation will investigate further Controller liability as a result of air-misses, and will seek more effective means of pursuading Governments to adopt more humane attitudes towards the Controller who may be involved in an air-miss. A paper will be produced on the principles upon which controllers may be guided and protected when dealing with Hijack cases.

On the subject of Recruitment and Training of Air Traffic Controllers, future resea rch will center on Training Conlent and Methods; Inter- relation of Recruitment and Training, with Automation ; Investigation on the type of Psycho logical Testing used for Recruitment; Investigation o n Advanced Training, Assessin g, Rating and Checking of Controllers.

On IFATCA's relations with th e Inte rnational Labour Organisation, it was with dismay that the Member Associations of IFATCA learned during their 14th Annual Conference at Melbourne that the Governing Body of the !LO had decided to postpone the Meeting of Experts on Problems concerning A ir Traffic Controllers as p roposed by the ILO Preparatory Meeting on Civi l Aviation, Geneva, 1974. The safety of air transport in all its forms is directly dependent on the efficiency of the Air Traffic Control Services. Since ATC- effi ciency is itself directly related to the co nditions of employment of ATC perso nnel, any delay in working towards a soluti on of outstanding problems in this area can only be to the detriment of fli ght safety. Therefore the Federation strongly urges the Governin g Body of th e ILO to reconsider their decis io n, and to make arran gements for the "Experts Meeting" to be held as soon as possible.

Preparations w ill be taken in hand regarding IFATCA rep resentation at the intend ed Internation al Civil Aviation Conference in 1977, to be co nvened by the ILO.

37

Technical Paper Presentations Time had been allocated on Thursday afternoon (17 April) and Friday morning (18 April) for the presentation of Technical Papers under the chairmanship of the Editor.

Each presentation was of 20 to 25 minutes duration. It was noticeable that the two papers presented by Australian airline pilots proved very popular, but all papers were of a high standard. It is hoped to reproduce some of them in future issues of THE CONTROLLER.

Exhibition by Corporation Members and other Organisations The following Corporation Members exhibited at the Conference: Cossor Radar & Electronics Ltd., Ferranti Ltd., International Air Carrier Association; International Aeradio Ltd., The Marconi Radar Systems Ltd., The Solartron Electronics Group Ltd., Software Sciences Ltd. and Stansaab Elektronik A. B.

Final Impressions of the 1975 Conference This Conference was undoubtedly another outstanding event in the history of the Federation, and an unqualified success especially when seen from an Southern Hemisphere point of view. The intense interest disp!ayed In the work of IFATCA by the large number of Australian co~­ trollers who attended the entire proceedings was a tome to all other participants who had come from far and wide to receive a royal welcome which can have few pa~allels.

The hospitality of the Australians will never fade m our memory, and it is difficult and unfair to single out names in this respect as this was a truly magnificent team effort.

The Conference had a number of highlights, such as the admittance of the Eurocontrol Guild into the IFATCA fold after its unsuccessful bid last year in Tel Aviv. During the debate on this issue, many of us could not help but recall Roger Bartlett's stirring words in Tel Aviv when he admonished those who had voted against admitting his Guild, for refusing to accept the hand of fri.endshi~ extended to IFATCA by a dedicated group of international controllers as international as the Federation itself. "We'll be back n~xt year", Roger had said, but - to eve~ one's regret _ he was not present in Melbourne to receive the Charter of Affiliation from IFATCA's President. Instead, Ted McCluskey a worthy representative from Eurocontrol Bretigny, ~hose words had done ~uch ~~ make t_he issue secure, had to deputise, but Rogers spmt was with us in that room, we felt.

Gratifying was the large turn-out of ~~ many representatives from Asian countries not yet aff11tated to IFATCA, although some of them were already in Australia for the purpose of attending an ATC supervisors course. Japan's Mr. T. Hayashi, at the head of a _three-man delegation, addressed the conference and received a very warm applause. Mr. Manin, in reply, said that he hoped to welcome the affiliation of the Japanese Association to IFATCA at next year's Conference. Other representatives were from Fiji, India Indonesia, Korea, Malaysia, Nepal, Philippines and Sing~pore. From Africa, representatives of the East African Community and Malawi attended.

Ghana's George Anthonio, as always prominent, led delegates to observe a minute's silence in the memory of Bob Shipley, and Daniel Gorin, not less prominent, was a dynamo of activity in whipping up interest for next year's

38

conference in Lyon. Michael Rock (USA) and Harri Henschler (Canada) in Committee "A" were instrumental in injecting some live comments and a fresh approach into some of the issues which came up for discussion, and one could not help but feel that the growing participation of our larger Member Associations in the New World was decidedly beneficial to the overall cause of IFATCA. Added to the tremendous Australian impact at this Conference, this trend typifies the new IFATCA, no longer a show run

by Europeans only but a truly world-wide international effort. Dean Dalzell and "Watty" Watkin of New Zealand and known to the IFATCA family through their literary contributions such as Dean's "Stress and the Air Traffic Controller", a paper still used today by the Federation, at last had the opportunity to meet the Officers and other stalwarts of IFATCA. Many new friendships were made "down under" and many promises to come back were given. "Tommy" Thomas and his Rhodesian compatriots were sadly missed at Melbourne, having falling victims to political influences which for the first time, and we hope for the last time, have upset the routine of the Federation.

The Conference also saw the standing down of one of IFATCA's longest serving Officers: Horst Guddat, whose farewell speech was followed by a standing ovation. The saying "There is a time of coming, and there is a time of going", could not have struck more convincingly too when we boarded the intercontinental flights at Melbourne's Tullamarine and Sydney's Mascot Airports on the long way home from an unforgettable experience.

GdB

Book Review Airmiss Analysis Report * An analysis of civil airmisses over the United Kingdom published by the Civil Aviation Authority shows that airmiss figures, taken in conjunction with traffic levels, can be used as a quantitative index of the safety of Air Traffic Control arrangements. Since 1968 there has been no growth in the UK airmiss rate per flight despite a considerable growth of traffic, and this is a strong indication that improvements of the UK Air Traffic Control system have been successful.

The analysis of causes shows that human error is the principal cause of airmisses, and that it is attributable equally, in terms of numbers, to the pilot and air traffic controller. Relatively few airmisses are the result of a technical system fault, but when these occur they are more likely to be within the high risk-bearing category.

This study was carried out by the CAA's scientific staff in close co-operation with the staff of the National Air Traffic Services. Although it was conducted for internal purposes, the Authority decided that the results should be published, and that in future more of its internal studies should be made available in this way to those outside the Authority with an interest in aviation. ( • An Analysis of the Civil Alrmlss Situation In the United Kingdom and Its relation to Colllslon Risk, CAA Paper 75001; Price :£ 2.50.)

The Low Drag/Low Power, One-Segment Approach

by Helmut Elsner, Lufthansa This article describes a noise abatement approach technique which was developed by Lufthansa after extensive trlals conducted at Frankfurt/Main Airport In co-operation with a number of other Airlines and with Air Traffic Control.

The procedure described offers a realistic alternative to the proposed 2-segment technique which was outlined In the May 1975 issue of "The Controller".

The increase of the approach noise problem has led the aviation industry, apart from reducing noise at the source, to consider flight procedures to alleviate noise nuisance underneath the approach path. One solution, the so-called low drag/low power approach technique, was pioneered by Lufthansa, and I feel that this forum is particularly suitable for discussing the technique since it relies on a close cooperation between controllers and pilots.

Ever since the ILS was introduced as the primary approach-to-land aid to increase both safety and regularity in air transport, the flight operational procedures in conducting the final portion of an ILS approach have virtually remained unaltered. The standard flight procedure employed hitherto would normally consist of straight and level flight at low speed along the localizer, at a height of 1500 to 2000 feet, until approaching the glide path. As soon as the glide slope bar started to move in from the top of the pilot's ILS indicator (or other display using input from the airborne ILS receivers), the gear was lowered and the flaps were extended to the setting required for landing. Thus the aircraft was established in final landing configuration at a point 6 to 8 n.m. from touch-down.

To overcome the large amount of drag created by landing gear and flaps and whatever other high-lift devices are incorporated in modern jet transport aircraft to allow flight at low speed, a great amount of thrust is required which consequently results in increased aircraft noise. It follows that the noise carpet laid down by an aircraft on approach could be reduced if it were feasible to shorten the length of that portion of the approach which is flown in the high drag landing configuration.

Although recognising the advantages in terms of approach noise abatement which would accrue from a delayed gear and flap extension, Lufthansa was reluctant to change the ILS flight operational procedures since these had proved their high safety standard throughout the years. In any event, Lufthansa made it a prerequisite that a new approach technique would have to offer the same degree of safety and would have to be capable of being applied as a standard procedure irrespective of prevailing conditions such as weather, traffic density, mode of operation (i. e. manual or automatic approach) since, for safety reasons, it would not be acceptable to have two alternative procedures for application depending on circumstances.

When a serious approach noise problem developed in the late 1960s in Offenbach, a community of 120,000 people located underneath the final approach path to the main landing runway pair at Frankfurt/Main Airport, the above position was again reconsidered by Lufthansa. It was felt, however, that the expertise of other airlines would be highly desirable to give as broad a basis as possible to whatever procedures would be found feasible. Thus in 1971 a

small group of specialists, including pilots from Lufthansa, Swissair, and from the Internal German Services Divisions of British Airways and Pan American, as well as representatives from ATC and the noise abatement officer of the airport, got together. In a series of meetings, they developed a detailed noise abatement approach technique which subsequently was subject to extensive in-flight trials for a period of more than one year. After the trials had proven both the feasibility of the technique, without derogation of safety, and the benefits in terms of noise abatement, Lufthansa made the technique its standard ILS approach procedure. It is now being applied on a world-wide basis throughout the Lufthansa network.

IATA has approved this method, and ICAO has circulated details of the Lufthansa low-noise landing approach to its member states. It may soon be incorporated in ICAO official policy as standard procedure. In the system, the aircraft approaches the airport faster, and from a much higher altitude, enabling it to be flown without power and, therefore, noiselessly to a point close to the runway, where an intermediate flap setting is used to slow it down. The final application of power can be held off until something like 40 or 50 seconds before touchdown, thus cutting the size of the area affected by noise by 50 %.

In greater detail, the procedure is as follows: In a low density traffic environment (i. e. in the absence of speed control instructions from the air traffic controller), the aircraft leaves the feeder fix at a speed which permits flight in clean configuration or with a negligible flap setting (e. g.

O degree or 2 degree flaps on the B 727). The resultant airspeed, for the majority of transport jet aircraft operated today, is around 210 knots. At approx. 12 NM track distance from touchdown, flaps are extended to an intermediate setting (e. g. 5 degree or 15 degree flaps on the B 727) and speed is reduced to approx. 160-170 knots. Unless the published procedure or the ATC clearance require otherwise, the glide slope is intercepted at a height of not less than 3000 feet, preferably even higher, permitting the aircraft to gradually bleed off speed while maintaining a constant and rather low thrust setting. For example, the thrust setting required for a B 727 flying in the high drag landing configuration is approx. 68 to 74 percent N 1 (for simplicity, 100 percent N 1 can be assumed to represent maximum take-off thrust, 50 percent N 1 representing flight idle, and

39

T

the unit N 1 being the percentage of fan compression).

However, a B 727 in the low drag configuration, coming down the glide path at 160-170 knots, requires only 55 to 58 percent N 1. Gear and final flaps for landing (e. g. 30 degree or 40 degree flaps on the B 727) are extended only in the immediate vicinity of the Outer Marker, from which point speed is further reduced to final approach speed.

It should be understood that thrust levels and flap settings are dependent on aircraft landing weight, airport elevation, wind conditions and temperature. By the same token, all speeds quoted should be understood to be applicable within a tolerance of Âą 10 knots.

Considerable noise abatement benefits are brought about by this procedure to communities located more than 4 NM before the landing threshold. Both the noise level (due to less thrust) and the duration of the noise event (due to the higher speed) are reduced. In the case of Frankfurt, noise measurements taken at Offenbach over an extended period have proved that the approach annoyance factor of the entire Lufthansa fleet has been virtually halved. In fact, with more and more airlines applying low drag/ low power techniques at Frankfurt, one noise monitoring point in Offenbach had to be decommissioned recently because most aircraft overflying it could no longer be registered due to their noise level being lower than that of the road traffic in the immediate vicinity of the monitoring point.

In favourable weather conditions and subject to the discretion of the pilot-in-command, establishment of the full final configuration may be delayed to be accomplished not later than at a height of 500 feet above touch-down zone. This means that although landing gear and final flaps are to be extended over the Outer Marker, excess speed over the target threshold speed may be bled off between the Outer Marker and the point when passing 500 feet, ensuring, however, that the aircraft is in the proper "slot" and in the full final configuration at that height.

In high density traffic conditions (such as at Frankfurt) the situation is different: it is the air traffic controller who then plays a vital role in the efficient application of the low drag/low power approach technique. Under these circumstances of course, speed assignments are given by the controller to ensure a homogenous well-sequenced traffic flow for optimum use of the available terminal area and runway capacity. Both goals, the latter as well as noise abatement, can be reached if the controller assigns the proper speeds.

Since the adoption of the low drag/low power scheme, Frankfurt controllers normally assign 210 knots to aircraft departing the feeder fixes. This leaves the aircraft with approx. 18 to 25 NM to go to the threshold, depending on the length of the radar vector. The lowest altitude assigned for glide path interception is 3000 feet (4000 feet at night). At approx. 12 NM track distance from the landing threshold aircraft will be instructed to reduce to 170 knots and to maintain that speed to the Outer Marker, based on the understanding that reduction to final approach speed will be accomplished by pilots on their own in the vicinity of the Outer Marker. On occasions, 160 knots must be assigned due to a particular aircraft type which cannot maintain 170 knots to the Outer Marker; this is still acceptable. Any speed below 160, however, or above 170 will normally spoil the entire noise abatement approach because then the pilot has to select an aircraft configuration which will require

40

power manipulations, and this will result in increased noise.

The above speed schedules suit the entire Lufthansa fleet which comprises B 737, B 727, B 707, B 747 and DC 10, and apparently all other jet transport types in general use today, as evidenced by the successful operation of the scheme by operators of other aircraft types at Frankfurt.

Once accustomed to the new speeds, controllers at Frankfurt seem to find no difficulties with their application.

Some even have expressed the opinion that the new scheme has eased controller workload; the latter aspect may, however, be an indirect result of the continuing educational efforts of the Frankfurt noise abatement officer who talks to airline chief pilots and line captains, explains and advocates the system and who has meanwhile got most airlines to the point where their pilots know which speeds, and why these speeds, will be assigned to them by ATC. Consequently controller/pilot co-operation seems to have improved as far as speeds are concerned.

Operating with the above fixed set of speeds has another advantage for controllers: the loss in separation between succeeding aircraft which commence the approach at 210 knots and wind up at a speed of 120 knots on the last four miles of the final approach (about the lowest final approach speed common with today's jet transports) is exactly 2 NM by the time Number 2 aircraft is over the Outer Marker. Thus, commencing for example with a 5 m!les sp~cing during the 210 knots portion, one winds up with 3 miles over the Outer Marker. In this case the 3 miles could only be infringed (by a very small margin) if the Number 2 aircraft used an appreciably higher final approach speed than Number 1.

Lufthansa is of the firm opinion that the low drag/low comparable noise rehef .as would be available from two-segment approaches, with one outstanding difference: the low drag/ lo.w power approach has already proved its practicability without the need for additional ground and airborne equipment, nor excessive flight crew training requirements and most important, without any safety derogation. To this end: Lufthansa subscribes to many of the objections and reservations to the two-segment approach which have been voiced. The two-segment NASA system in the U.S. entails that a~ avionic installation costing $ 35,000 must be installed on aircraft, and that runways require ground guidance equip~ent worth $ 50,000, but the Lufthansa system costs nothing. Although a comparative flight evaluation of the noise benefits derived from the two-segment approach versus those available from low drag/low power has not so far been made, calculations indicate that overall noise reduction is almost the same. Furthermore Lufthansa claims that the two-segment approach will be obviated by the time it has completed development, by the arrival of quieter, more advanced engines. po~er a~proach technique brings about a

And L~f!ha~sa feels that low drag/low power, with active ATC part1c1pat1on from the beginning, offers a both pilot as well as ATC - oriented safe means of approach noise aba~eme~t for application until such time the industry can design aircraft which (a) are so quiet that pilots will be able to handle them without the need to apply special noise abatement techniques and procedures, and (b) will permit co~trollers to manage their traffic according to purely operational and ATC requirements, rather than to noise abatement considerations. (~dapted from an article that first appeared In the Journal of Air Traffic Control)

The Pilot's Point of View Separation Separation issues are again very much under review and IFALPA is heavily involved in continuing discussions of these issues within the ICAO Review of the General Concept of Separation (RGCS) and SST Panels in regard to worldwide standards, and within the North Atlantic Systems Planning Group (NAT SPG) with regard to NAT Regional standards.

Considerable pressure is being exerted by some States and IATA to reduce some of the present separation standards; for example: from 2,000 feet to 1,000 (or 1,500) feet above FL 290; from 120 n.m. to 60 n.m. for INS-equipped aircraft; from 15 minutes to 8 minutes longitudinally, and from a planned 4,000 feet vertical separation to 2,000 feet above FL 400, for the SST. The motivation is laudable; it is to increase the capacity of the airspace so as to accomodate the increasing volume of traffic, reduce delays and minimise fuel costs.

Invariably, IFALPA is in opposition to such proposals until they have been proved to be safe by the statistical and mathematical processes already approved by ICAO. This simple and logical attitude finds little favour in some quarters, however, and the situation has now been reached wherein IFALPA is openly accused of being obstructive by always wanting proof that a particular separation value is safe. The new line being taken by those who say this is to challenge IFALPA to prove that the proposals are unsafe!

This technique is not new, of course. It is well known to the legal profession and is a favourite ploy of politicians.

What is at stake in separation matters, however, is not an academic legality or a political philosophy, but the pilot's neck - to say nothing of the lives of his crew and passengers. In the ultimate, the most convincing proof that separa-

tion is unsafe is a mid-air collision. In the event, it so happens that the method of proving that a particular separation is unsafe, is precisely the same as that already adopted by the ICAO RGCS Panel and the NAT SPG to prove it is safe; that is, by determining a target level of safety and by then calculating the risk of collision in specified conditions on the basis of statistically viable and known (not hypothetical) navigational performance data. This method takes account of all measurable factors derived from actual operating experience and has the special merit of flexibility, in that when navigational performance improves, for whatever reason, the separation values can be reviewed and, if necessary, reduced. By this method the present composite separation values in the NAT Region were adjudged to be safe and were thus accepted by IFALPA. Airline pilots, by definition, are intelligent and responsible people. They are quite well aware of the airspace, operational and economic problems involved when large separation values are applied. They, too, dislike delays, diversions and excursions from desired track and flight level. At the same time, they are also well aware of the significance of deliberately placing aicraft in relative close proximity to each other at high speeds in an unstable atmospheric environment, and of the fallibility of the equipment and human beings concerned, including themselves.

In short, because they are the people most directly concerned, their judgement in matters of flight safety merits careful, close and sympathetic consideration. It is illogical and unreasonable to criticise them for seeking proof of safety and the height of folly to impose, or try to impose, on them arbitrary decisions contrary to their judgement. . We now have a suitable and agreed method of adjudging whether separation is safe or unsafe. Let us stick to it.

(Capt. V. H. King in "IFALPA" Bulletin)

Fuel Economy With Linear Holding

by M. A. L. Randell, IFATCA Standing Committee Much has been written in recent months about the need to conserve fuel; much has also been said by both Airline Pilots and Air Traffic Control Officers about how best this can be achieved. There is of course some division of opinion between these two groups as to the respective methods to be used. However, one aspect is common to both parties. The pilot is aware of the need to conserve every kilo of liquid gold, not only as a result of the price, but more often because he is short of this essential commodity for all sorts of reasons, the most frequently quoted being Flow Control restrictions or Air Traffic Control delay.

The Air Traffic Control Officer is also becoming increasingly aware of his essential role of Fuel Economist. In many instances however, his task is frustrated by airspace restrictions and sometimes by a lack of appreciation of aircraft performance in relation to fuel consumption.

At a Meeting in December 1973 of the IFALPA RAC/ COM Study Group, a discussion took place concerning the

need to conserve fuel on SSTs and to absorb holding delays by a method of en-route Linear Holding. This entails forecasting in advance an arriving SST's EAT and allowing the inbound aircraft to absorb any holding time by reducing speed at an economic cruising level whilst at the same time conserving fuel. ' It is of course apparent that this same procedure could be applied to conventional subsonic aircraft with a beneficial effect. It is also true that this method of linear holding is used on a limited scale at the moment by some Air Traffic Control Officers.

The author would not dispute that the problems of this sort of operation are many and varied, to list but a few: 1) En-route separation problems between aircraft flying at normal and reduced speed.

2) Reduced flexibility of aircraft operation. You can never regain the lost time if suddenly conditions at destination improve.

41

r

3) An accurate forecast EAT at a suitable distance out seems beyond the present capability of ATS units.

The immediate advantages are: 1) Reduced congestion in TMA holding areas.

2) Fuel saving.

However, it is not beyond the capabilities of an Air Traffic Control Officer to overcome such problems in order to play a thinking part in airline fuel economics. The problems of forecasting EATs are problems which should make our new found friends the Computer Programmers ecstatic.

As a result of the original discussions at the IFALPA RAC/COM Study Group Meeting, the IFATCA representative present asked if it was possible to have examples of fuel

Short Range Aircraft

1.

3.

1.

3.

1.

3.

1.

2.

3.

1.

2.

3.

BAC 1-11 FL 300 Standard Cruise Linear Holding FL 200 Standard Cruise Linear Holding Boeing 737 (3) FL 350 Standard Cruise Linear Holding B-727-200 (4 ) FL 310 Standard Cruise Long Range Cruise Linear Holding FL 250 Standard Cruise Long Range Cruise Linear Holding

500 MLS in time (hrs)

and time saving prepared in order to compare the savings on differing aircraft types. The information reproduced was kindly supplied by IFALPA members and collated by Captain W. K. Jennes of the Dutch Air Line Pilots Association.

The data is based upon an aircraft 500 miles (MLS) out receiving an EAT of 1.30 hrs. later than its estimate for the holding fix. The flights are performed in three different ways.

1) Proceeds at his standard cruise speed and absorbs the delay in the holding stack.

2) Reduces to long range cruise and absorbs the remaining delay in the holding stack.

3) Flies at minimum drag speed (1.1 VL/D max) Linear Holding.

Time loss in min/hr; min/100 MLS

Holding (min)

Total Burn-off {kg)

Fuel Gain

O/o

1.06 1.30

20'

4.5'

24' O'

3.690 3.130

15

1.10 1.46

31' (2);

7'

20' O'

4.130 3.200 (1)

22.5 (2)

4.5'

FL 200 23' O'

3.580 2.950

17.5

1.5' 2.5'

FL 150 20' 12' 7'

7.390 6.570 6.665

11 9.8

26.8 (2) 26 (2)

1.07 1.30

20'

1.10 1.18 1.23

7' 11'

1.06 1.20 1.24

12.5' ; 2.5' 16.5'(2); 3.5'

24' 10' 6'

8.670 6.340 6.420

1.00 1.05 1.14

5' 14'

1' 2.75'

30' 25' 16'

16.240 15.160 14.400

6.6 11.3

1.02 1.05 1.19

3' 16'

0.6' 3.5'

28' 25' 11'

11.695 10.995 10.425

6 10.85

1.03 1.07 1.15

3.5' 11'

0.75' 2.5'

27' 23' 15'

8.645 8.030 7.655

Long Range Aircraft at max. Landing Weight, ISA - no wind

1.

2.

3.

1.

2.

3.

1.

2.

3.

B-747 MLW 255.000 kg FL 300 Standard Cruise M .84 Long Range Linear Holding DC-10 MLW 182.800 kg Standard Cruise M .83 Long Range Linear Holding DC-8-63 MLW 117.000 kg Standard Cruise Long Range Linear Holding

(1) With speed increase to cover distance In 1.30 hr.

(2) The great improvement in savings is attributable to the very high fuel flow v v

aso

7.1 11.4

low TAS In

(3) Very short range ale 500 MLS appr.-max. range with full load. Sa me HO fuel at or 250 TAS I normal cruise at lower Flight Levels.

(4) Includes climb and descent for short range operation probably the most realistic one It is v ncrea~es and requires one 3500 at FL 350.

results as for BAC 1-11 and B-737 If climb and descent are eliminated.

42

¡

ery we I possible that we obtain the same

News from the Federation IFATCA Presence at the Paris Air Show, May 30 - June 8, 1975 For the first time in the histo ry of the Federation, IFATCA - in c ollabo ration with APCA (the French Association) - has operated a Stand at an international air display. Judging from the interest displayed by the public, this public relatio ns venture can be described as an unqualified success. In attendance were President JeanDaniel Monin, Horst Guddat and Ge de Boer. Mr. Monin and Mr. de Boer took the opportun ity to visit the Paris Centre and the Eurocontro l Experimental Centre at Bretigny-sur-Orge. At Bretigny, th e visitors were received by the Director of the Centre, Mr. D. D. Lipman, while Ted McClus key took them on a tour of the facility.

IFATCA is much indebted to President Dani el Gorin of APCA for the organisation involved and to th e many members of his A ssociatio n who so willingly took turns to man the Stand and who extended such warm hospitality to the visiting IFATCA officials.

Participation in the Work of an ICAO Study Group The Fede ratio n has received an invitation from Dr. Assad Kotaite, Secretary General of ICAO, to take part in the wor k of an ICAO Study Group o n Monito ring Devices in ATS Units, and the Federation has accepted the ICAO offer.

The work invo lves the fu rther deve lopment of the provis io ns in ICAO 's Annex 11 to identify the need for, and the fo rm of p resentation of instantaneous indicati ons in ATS units of the o perational status of visual and non-visual aids esse ntial to app roach, landing and take-off.

ICAO has decided that preparatory wo rk on this lask can best be pursued by a Study Group composed of members well versed in the operational and technical fields involved. It has therefore decided to establish a small group of experts f rom selected States and Internationa l Organ isations to work w ith members of the ICAO Secretariat who are s peciali sts in the technica l and operation al fields concerned.

IFATCA's Li aiso n Officer w ith ICAO, Don McLean of the Canadian Association, has been nominated as the Federat ion's representat ive, w hile the Canadian and United States Membe r Associations have been asked to provide a stand-by shou ld Mr. McLean for any reason be prevented from attending.

Nicosia FIR IFATCA's President, Mr. J.-D. Mon in, has written as fo llows to Mr. Walte r Binaghi, President of the ICAO Council : " The President and the Executive Board of the Federatio n took the oppo rtun ity on t he occasion of its Annual Conference in Melbourn e 14-18 Apri l, 1975, to meet the Delegates of th e Turk ish and Cyprus Associations. Th e matter of restoring the normal Regional Planning faci lities was conside red at this meeting and also in closed session in th e appropriate Conference Committee.

The IFATCA Stand, wh ich we shared with APCA at the Paris-Le Bourget Aero Salon, 30 May unti l 8 June 1975. From left to right, Mr. Jan Yvon and Mr. Gerard Astegianl of APCA. and Mr. Ge de Boer, editor of THE CONTROLLER.

The result of the deliberations is that the Federation has reached agreement with t he Turkish and Cyprus Assoc iations after a full review of all the factors. The Agreement is that the restoration of t he navigation and communication facilities established on the Nicosia International Airport should be affected without delay on an urgent basis and to be improved wherever possible. The Federation is aware of the talks to be opened on the whole question of Cyprus in Vienna, but I wou ld be grateful if you would make it known to the Ministers d ue to meet in Vienna that IFATCA and its Tur kish and Cyprus Associations stro ng ly request the immediate resto ration of t he above facilities and the associated Air Traffic Services as an essential step in the maintenance of a:r navigation safety."

Mr. Binaghi has replied as follows to Mr. Manin : " Since August of last year we have been following the situation c losely and doing our best to obtain an improvement in the air navigation system in the Eastern Mediterranean area. However, there are several non-techni cal c onsiderat ions that play an important role in this matter and so far we have not met with success. Neverthe less, we continue in our efforts and I was glad to hear of the action taken by your Federatio n."

43

News From Member Associations Australia The Jandakot Accident . ago at Jandakot Aerodrome, two light airSome t 1me • . .d d during the landing phase. During subsequent craft co 11 1 e ·ngs the Tower controller was foun d pa rtl y court procee d 1 • . · d 'bi f the accident. An appeal against that JU gresponsi Je ot~ e Burt in the Supreme Court of Western ment (of us ic . . . tater handed down by Justices Virtue, Lavan Australia) was . · · in an unanimous dec1s1on, the J us t"ices and Wallace, an d . . f Judge Burt's proportioning of the degree o T .

1 1 upheld . ~ ~ f the accident - 40 O/o to the controller, respons1b1hty or . . d 30 O/o each to the two pilots. and Wallace placed heavy emphasis on an Both Lavan . .

4 describing the functions and respons1ANR's 93 an d 9 · ft d ... f ATC to prevent accidents between a1rcra , an bihti~s 0 o·inted out that whereas pilots should be Justice Lavan .P itations that operations . ·m an A ero d rome aware of the I im . th" .

1s in no way . e laces on the ATC service, Tra~i~ Zon h P esponsibility of the Air Traffic Controller. diminishes ·t d" e r ted that where .1t says ·m Australian · Reguln~eed, he 1,~J 1dcagment by ATC of aircraft position and flight lat1ons uff" ·ently precise . . . to enable AT c to ·md"1. that SU ICI " • • p ath IS not . t · craft by visual means . . . 1s warning not vidually direc air .

• t but also to the controller to exercise extra only to the p1 1o • h I d . d these circumstances. To quote t e earne ~aut1on.. unmer "udgment the controller was negligent in actJUdge, In Y J mption that his judgment of the relevant ing upon the assu h" of the two aircraft was correct .. . J ust"ice 1 di.stances fro; ~ing that "observations of the positions Virtue agre.e ' sah a situation were notoriously unreliable of aircraft in sue · ently unsafe for him to re Iy on t he It was cons equ · ·. ·. which he (the controller) had formed, and to conopin io~ f further with the aircraft during their approcern h1msel no ach to land". "d "I b r th . I e ieve e s1mp e In conclusion, Justice Wallace .sa1 ' th' appeal is the failure of the controller to . solution to is . . . te explanation of his involvement otherwise . give an adequa . . · the two aircraft in question . . . that the than observing . . d to keep a good look out at a time when controller f a1 1e this was his duty"· . .

This decision is binding on all future Judgeme~ts. m ·a and serves as a precedent for all s1m1lar Western A us t r al 1 • . . . . ·n Australia Canada, NejQ Zealand, Britain and cases h eard 1 • India.

Canada Anonymous Incident Reporting Following the PATCO precedent, CATCA .ha~ decided • ent a similar scheme, and has distributed an to imp 1em Anonymous Incident Reporting F~rm to all Branches. The Form is the gathering of anonymous reports purpose Of the .. of incidents, and hazardous or d~ngerous cond1t1ons and situations. Absolute confidentiality 1s assured, and CATCA's National Office has made it clear that it is not interested in the individuals involved, rather, the circumstances of many incidents when compiled and evaluated may show the pattern of a weakness or problem in the ATC system which, once recognized, may be resolved.

The reporting form is to be submitted by the individual direct to the National Office where the operational information will be extracted from it and the form itself destroyed. The Association has appealed to all its members to participate in the program, as their completed forms may some day help to prevent a similar occurrence.

France The Mid-Air Collision near Nantes, March 5, 1973 The French Commission of Inquiry has determined that the collision of two Spanish airliners - an Iberia McDonnell Douglas DC-9-32 and a Spantax Convair 990-30A near Nantes resulted from a complex sequence of events dominated by poor communications, inadequate radio and radar facilities and confused ATC procedures. The DC-9 crashed, killing 68 persons. The 990, despite loss of a portion of a wing, landed safely at a French air force base. The collision occurred at a time when French civil controllers were on strike and military controllers were operating under a contingency system instituted 10 days earlier.

The Commission listed the following sequence of events as leading to the collision: Assigment of FL 290 to both aircraft when both were estimating arrival at Nantes at the same time on converging courses.

Decision by the Menhir Centre to keep the Spantax 990 at FL 290 and to delay its arrival at Nantes by 8 min., "although a simple change in flight level without any change in timing could have been applied".

Lateness of the Marina Centre in confirming to the Spantax 990 the instructions to lose time, "lateness that increased the urgent, compelling and exceptional nature of this instruction (8 min. to be lost over a normal flight of 9 min.)".

Delay by the Spantax aircraft "in making known the manoeuvre by means of which it could comply with the accepted instruction (360 deg. turn in about 8 min.)".

Delay by the Marina Centre in giving the Spantax aircraft instructions to change frequency and contact the Menhir Centre. The instruction was transmitted 2 min. after the Iberia DC-9 has passed the boundary between the two sectors.

Failure of both the Marina Centre and the Spantax aircraft to understand each other, causing the Spantax aircraft to remain on the Marina Centre frequency and to start the delaying turn too late and without clearance to do so.

The Commission also cited the Marina Centre for failure to carry out the proper co-ordination before assigning the Spantax flight to FL 290 and said the controller there ,,incorrectly used a term of international phraseology". As a result, the Spantax aircraft was left for nearly 2 min. in uncertainty about the final instructions. Further, the crew of the 990 did not assess the situation correctly after receiving and confirming the instructions to delay, and the Marina Centre authorized a change of frequency when the aircraft already was in the Menhir sector and without knowing the exact position of the aircraft.

44

1

..

)

Greece

2. The exchange of Technical and Professional information can but only help to improve the Guild's knowledge;

On the eve of IFATCA's Melbourne Conference, news was received from the Greek Association that their negotiations with the Greek Administration with a view to improve the employment conditions for Air Traffic Controllers had ended in deadlock, and that strike action was being contemplated. The situation deteriorated further when the Government decided on a general Mobilisation of all Greek controllers, which prevented the Association from being represented at Melbourne.

3. The Guild has improved the IFATCA, and will continue to do so, by its input in almost all fields of activity and gain in return;

IFATCA's President has written to the Prime Minister and the Minister of Transport in Greece, and has appealed for everything possible to be done to restore to normal the situation in the country's Civil Air Traffic Services. Mr. Monin said that his approach was based on purely professional grounds and in no way represented any attempt by the Federation to get involved in the situation. "But IFATCA knows from experience that whenever the atmosphere deteriorates within the ATC Services due to difficult circumstances and when additional pressures are exercised upon Air Traffic Controllers, the SAFETY in the air becomes impaired with all the consequences this may have for human lives and property. IFATCA trusts that a satisfactory solution will soon be found in the cause of SAFETY and efficiency of international civil aviation."

The Director of the Greek Civil Aviation Authority, Mr. E. J. Deros, on behalf of the Prime Minister, has repl~ed to the Federation saying that the ATC personnel working under his direction have always been treated with care and understanding. "The work of the Greek Association is fully appreciated and we are willing to adopt any suggestion which might assist in the im~rovement of the safety of flights as well as in the creation of more comfo~­ able conditions of work for the above personnel, but m spite of the understanding we have shown for d~mands of the said personnel it has not always been possible to satisfy all of them d~e to reasons of objective inability. Just now 1 am in the pleasant position to inform you that the situation in the Greek ATC Services has been restored to normal."

The Greek Association has since confirmed to IFATCA that the Mobilisation order has been rescinded.

Further, information has been received that Greek controllers now enjoy a 35 % increase of their basic salary, plus a special allowance of Drachmas 1,000,- for those working in Radar positions, and Drachmas 600,- for ot~er positions. Also a special committee was formed to examine and re-organize the Civil Aviation Authority of Greece, where necessary.

United Kingdom A Working Group of the British Guild has produced a paper for the Executive Committee on the question of the Guild's continued membership of IFATCA. The points reproduced below have been accepted as guidance material in favour of continued membership, should the question be raised in the future.

1. The basic objectives of IFATCA are the same as the Guild's;

4. The information obtained from Conference can and will be made available through the Guild's official publication ("Transmit" - and a very good publication indeed - Ed.) to the membership. This helps to spread the worldwide views to the members; 5. Membership should help: 1) maintain the high standard of the profession; 2) maintain the high efficiency of the profession; 3) Advance the profession; 6. Membership will help: 1) with exchange of information; 2) raise the standard of knowledge; 3) with dissemination of information; 4) provide facilities for discussion at Conference of common matters to the profession; 5) allow transmission of international information to United Kingdom interested parties.

7. The cost of membership is a worthwhile investment.

United States New Classification System for Controllers In a recent meeting with PATCO's Executive Vice President Robert Poli, the PATCO members of the Classification Committee discussed the next stage in the development of the project: analysis and comment on the rough draft of the elements to be covered in the new Classification System. Presently being developed, based on data supplied by controllers, is a model, or a formula, which describes the duties of a terminal controller and one for a center controller.

"The present classification system, established in 1968, has overemphasized a facility's volume of activity as virtually the sole basis for determination of a controller's workload", said Poli. "The key word, left out in 1968, was 'complexity'. PATCO and FAA members of the team have worked diligently in carving out new ways of measuring that all-important term, job complexity. It is obvious that many significant work factors that add to complexity have been ignored in the past. The controller's job is far more complex than had been acknowledged in the previous study. The task of the Committee is immense, however. We deal, for example, with the high degree of independence and responsibility of the controller. Supervision is minimal when compared to other professions", said Poli.

Because of the excellent return and handling of data by controllers, the Committee now has a wealth of statistical data which proves just how complex this work is. The work of the Committee can be thought of as a formula. In this formula the quantities that must be measured and weighed are volume, complexity, knowledge of equipment, and the inherent responsibilities of the controller profession. The present data, now analyzed factor by factor in FAA computer runoffs, were gathered by factfinding results, controller interviews, and facility observations. But another essential ingredient has been the use of controllers who have added their occupational knowledge and experience.

The report in no way diminishes the complexity of work at the highcount facility. What it does indicate, however, is that high complexity can be encountered even in a facility 45

.d t"fy complexity it was where traffic cou nt is low. To 1 en 1 • • ·ob into a number necessary to break down a cont ro IIer s J of statistically analyzable job factors.

PATCO Safety Proposals Seconded by ALPA Strong support for PA TCO's safety program, p rese~ted at the rece nt National Transportation Safety Board heanng.s into the Dulles-TWA c rash has been given by the President of the U. s. Air Line Pilots' Association, Cpt. J. J. O' Donnel l. After PAT CO Presid ent J. Leyden had g iven testimony, O'Donne ll suppo rted virtually all of PATCO's proposals. T his marks the first time t hat the two g roups have shown a com m on front on such an extensive number of needed safety measures.

Among the PATCO p roposals, ALPA supported: One standard manual fo r cont rollers and pilots, with participation of both g roups with FAA in the preparation ; Identical approach plates fo r both controlle rs and pilots; Standardized training for controllers and pilots, and support for the contro lle rs' FAM trip program and the v isiting of ATC facilities as part of airline pi lot training ;

PATCO and controllers should be on FAA technical co mmittees ("It's close to criminal to exclude controllers" ) ; FAA must engage more controllers and reduce substantially the number of hours they handle live aircraft (" I don't want a controller handling my aircraft who has been working for even four hours steadily"); There should be an immunity program wherein controllers and pilots can report incidents without pu nishment, such as the successful system in A ustralia.

Th e only PATCO proposal not expressly backed w as the need for PARs. The ALPA President said he was unfamiliar with the new AN/TPN/19 system, but t hat he would have his technical committee ev aluate it (it is hoped to publish a detailed description of this revolutionary PAR equipment in a future edition of THE CONTROL LER - Ed.).

(On April 4, 1975, PATCO announced t hat FAA had decided to institute the immunity p rogram for pilots, controllers, and other aviation support personnel reporting aviation system deviations and er rors, which program had long been recommended by PATCO as the best w ay to prevent future crashes.)

Airports and their Control Towers

by Horst Guddat

Caracas-Maiquetia "Simon Bolivar Airport"

The new Mai quetia Tower.

Flying in South America is quite an experien ce, which the writer discovered when he flew across th at continent recently in the cockpit of an airliner. In thi s case, from Ri o de Janeiro, Brazil, to Caracas, Venezuela.

46

Because of high tem peratures and humidity during the day, most international flights are schedu led for nig ht t ime.

Saint-Exupery's famous "Night Flight" came into mi nd when t he flight passed over the wide Amazonas area, with no sign of life on the ground be low which was in total darkness, with no lights of settlements, j ust the c lear and bri lliant light of t he stars. Flying at FL 370 gives one the feeling of riding in a space ship. The stars look so near that one is inclined to try and touch them. It's an impressive and unforgettable spectacle. Moments to start dreaming.

But not for the pilots. When the fi rst lights of Venezuela came into view, torches at oi l rigs looking l ike candles in a dark garden , the pilots were busy trying to make contact with the Air Traffic Control Centre at Maiquetia. When contact was established, all the f lig ht plan information was given, apparently as there are no ground communications.

The f light was cleared direct to the approach fix and for descent, with no delay.

There were no other flights in the area, except for an overflying PANAM Cl ipper (PANAM seems to be everywhere in the region) , southbound towards Rio. And she was giving all her flight plan data for everybody's information, presumably as a precautionary measure to info rm other flights in the area, as a supplementary to the Air Traffic Control Service? Meanwhile we had reached 2000 ft above the sea on an ADF approach to Maiquetia, parallel to the coast, and the pilot was saying : " Roger, cleared visual approach to runway 08." Although the p ilot pointed out a red light at nine o'clock to our position, I couldn 't see the runway. Then , a left turn for base leg, further descent, still no runway in sight. We were heading for the mountains which are pi ling up all along the coast mu ch higher than we were flying. For the first time I felt a li ttle uneasy, but the pilots seemed sure of their flight path . Then , another left turn, we came around a small hill where t he red light beacon was located, and suddenly fou nd ourselves on a two miles' final approach, the runway coming into view.

at seemed only seconds when the aircraft touched down; moments of hectic activity in the cockpit. A tremendous thunder and shudder going through the aircraft, reverse thrust and brakes in order to make the last turn-off from the 9000 ft runway with a considerable downward slope (threshold elevation r/w 08: 230 ft; at the far end: 99 ft.) It was with relief that I put my feet on solid ground again.

My respect to all flight crews who fly into Maiquetia Simon Bolivar Airport. It requires skill and experience.

The NOB being the starting point of the approach procedure is not much of a help. The VOR/DME is not fully reliable. An ILS is not available. So it's the pilot's proficiency and the weather you have to rely on. Consequently only visual approaches are permitted, and the approach charts say "if during visual approach contact is lost, initiate immediately climbing turn to the north", the open sea The Tower is not equipped with Direction Finding (D/F), nor are any other ATC facilities. The Radar, an old Decca AR-1, is not working all the time. Controllers only have a very restricted repertoire of standard English phraseology at their command, as the Civil Aviation authorities, until now, have not provided for English language courses. This really could be a severe handicap under non-routine and emergency situations, where foreign airlines are involved.

Our friends in Venezuela really face a lot of problems; understaffing, old and unreliable technical facilities and working conditions which leave much to be desired, are but some of them. Fortunately there is light on the horizon.

The almost 30 years' old Control Tower is being closed down, and a brand new modern construction, 47 meters above the new airport area, will house the Tower controllers at the time this story is published. Of the 13 colleagues

"manning" the Tower cab, 9 are female controllers. Some 50 controllers work in the Centre; 18 in Approach Control.

Simon Bolivar Airport has about 200 landings a day.

From the new Tower you have a fine view towards the sea and the small "valley" embedding the airport, and all airport installations are clearly visible. A new runway of 3500 meters is ready for operation; only the connecting taxiways, the lighting and the installation of the ILS were not completed at the time of my visit. When the new runway 09/27 goes into operation, the old 08/26 presently in use will be closed and give way to more airport buildings currently under construction. Eventually there will be an entirely new airport; the recently introduced West Terminal was the first step.

Back to the new Tower cab: it is spacy and provides for many operational positions. The equipment looks good and there are some sophisticated gadgets like automatic runway visual range indicators (at an airport with more than 300 days of sunshine a year), but a D/F is still missing. However, there is a lot of space left for further additions. More equipment will arrive as soon as the multimilion dollar improvement programme starts moving. Over the next three years, ATC equipment and ground installations at some 27 Venezuelan airports are scheduled for renewal and modernisation in order to keep pace with the rapid progress of aviation and to meet the requirements of the steadily increasing volume of air traffic.

It is hoped that when the financial programme is fully moving, all problems now existing in ATC Venezuela will disappear, and that the service will benefit to the extent that the standard of safety in air navigation will be of the highest order.

LUFTHANSA, Germain Airlines, publishes own approach charts to aid pilots.

47

News from Corporation Members International Air Carrier Association

Ferranti Limited A contract has been awarded to Ferranti Digital Systems Division by the National Air Traffic Services of the U.K. Civil Aviation Authority, to carry out the first phase design of an ATC flight data processing system for the Oceanic Area Control Centre at Prestwick, Scotland. The contract calls for Ferranti to define an automatic data processingdisplay-communications system to be available for operation in 19n. It is to be designed to meet the peak traffic needs projected for 1982 with capacity for expansion to cope with double this volume.

The airspace with which Prestwick OACC is concerned covers the North Atlantic out to 70° W. Control is exercised out to 300 (approx. halfway across). At this point, the OACC at Gander, Newfoundland, takes over responsibility, but planning by Prestwick must be such as to ensure that adequate separation continues to be maintained for westbound aircraft. On the same basis, separation for eastbound aircraft is planned by Gander to remain adequate in relation to other traffic until the aircraft enters U. K. (or French or Spanish) domestic airspace. Separation standards are much greater over the ocean than they are within domestic airspace where aircraft are under radar surveillance, and once an oceanic flight has been allocated a track and level, these are normally maintained throughout the flight.

w

Depending on meteorological conditions, certain tracks and levels may have advantages in terms of winds, other weather and aircraft performance and thus tend to be more popular. Tracks and levels are computer-allocated on the basis of a request by the pilot of each aircraft. When the track and level offered have been accepted, the computer prints out a number of flight progress strips for the crossing. Electronic tabular displays are expected to supersede the printed strips in due course.

The system currently in use at Prestwick OACC uses a Ferranti Apollo computer which holds in its memory the tracks, levels, speeds and times of all aircraft flying within the OACC boundaries. Apollo is probably the oldest computer in current use having served in an evaluation role since 1961 and then operationally on the North Atlantic.

The purpose of replacing Apollo is to provide more sophisticated and reliable automation thus-reducing the element of manual control and at the same time make better use of the airspace available, which also makes for saving aviation fuel.

(International Aviation Review)

Last May the Spanish charter airline TRABAJOS AEREOS ENLACES (TAE) joined IACA as an active member.

With headquarters in Palma de Mallorca (Spain), TAE presently operates a fleet consisting of the following aircraft: one DC-8-53, two DC-8-33, one Super Caravella, and one DC-7C. The Company began operations in 1967 with a fleet of three DC-7 and, later, one BAC-111 aircraft. In order to modernize its fleet to one which would best cater for the charter market, TAE temporarily suspended flying in 1970 until it was able to purchase two DC-8-33 from the French airline UTA. TAE is authorized to operate international passenger and cargo charters. Its main markets are in Germany, Holland, Scandinavia and Spain. It is 99 O/o owned by one of the most important Spanish shipping companies, Naviera Aznar, part of a group of companies with interests in banks, insurance and mining.

TAE has a nominal capital of Ptas. 80 million, represented by shares of Ptas. 1000 each. Eduardo Aznar Coste is President of TAE and Santiago de Andres is General Manager.

In June, Mr. F. A. Pfiffner, Director General, announced that IACA had accepted the Belgrade based Yugoslavian charter airline AVIOGENEX, and the Danish charter airline MAERSK AIR as active members.

Aviogenex is the air transport division of Generalexport, a Belgrade based import/export concern and is authorized to operate both passenger and cargo charter flights domestically and internationally. Aviogenex was the second Yugoslavian airline to join IACA. Its fleet consists of Russian TU 134, twin engine jets.

Maersk Air, headquartered in Copenhagen, operates passenger, freight and executive charters throughout Europe and North Africa and also has a helicopter division serving the North Sea area. Among others Maersk Air operates the four engine Boeing 707 jet. It is the third Danish airline to join IACA. The above three airlines bring total IACA membership up to 16. Other IACA members are: Capitol International Airways (USA), Conair (Denmark), Euralair {France), lnex Adria Airways (Yugoslavia), Overseas National Airways (USA), SATA {Switzerland), Saturn Airways (USA), Spantax (Spain), Sterling Airways (Denmark), Transavia Holland (Netherlands), Trans International Airlines (USA), Wardair (Canada) and World Airways (USA).

~nternational Aeradio Limited Contracts have been secured worth ÂŁ 910,000 for the supply of equipment and provision of technical and operating staff for a new international airport now being built in the Arab Emirate of Ras Al Khaimah.

Equipment will include all navaids, Air Traffic Control and radio communications, fire and rescue vehicles, and ground handling equipment for passengers and aircraft.

IAL will train nationals in many of the management and operational activities.

48

Marconi Radar Systems Limited The Digilux "touch sensitive" display input device, developed by Marconi Radar Systems Ltd., in which the operator's finger interrupts a grid of invisible infra-red light beams to communicate with a computer, was shown publicly for the first time at the last Farnborough and Paris air shows. Digilux does not require actual finger contact with a bare wire, as in Marconi's Touchwire system; instead, a

finger placed on the face of the cathode ray tube screen intercepts two IR beams perpendicular to each other, enabling the system to determine the "coordinates" of the finger and signal the computer. Demonstration unit utilised four horizontal beams and eight vertical beams.

Plessey Company Limited Plessey Navaids, U. K., has won two contracts worth

£ 360,000 for instrument landing systems. The Indian Department of Civil Aviation has ordered STAN 37/38 ILS for Madras and Nagpur Airports; the same system is already in use at Bombay, Calcutta and New Delhi. The company's second order was for two Cat 2 PLAN 17/18 ILS for Khartoum Airport; these will be the first instrument landing systems installed in the Sudan following an extensive evaluation programme by the country's Department of Civil Aviation.

The systems will be installed at each end of the runway to cater for the significant wind change experienced for four months of the year.

Software Sciences Limited The U. K. Civil Aviation Authority has placed a contract for the study of the "operational need" for air-ground data link in Controlled Airspace and Upper Airspace Special Rules Areas within the U. K. FIRs. The use of automated digital communications ("data link") between aircraft and ground stations has been an attractive proposition for some time; although there have been successful demonstrations of feasibility in the U. S., U. K. and France, it has not yet been adopted as part of the international civil aviation telecommunications system.

The study will provide a quantitative forecast of the expected growth in communications traffic and will develop criteria to describe the operational effectiveness of digital data link as compared with conventional radio telephony.

Operational and technical developments likely to influence the ATC system from the 1980's onwards will be taken into account.

Representatives from the Directorate of Operational Research and Analysis, the Directorate of Control (Plans) and the Directorate-General of Telecommunications are working in close liaison with the company's consultants.

Racal-Thermionic Limited The company reports major purchases, valued in excess of £ 220,000, of their International Communications Recorder by two customers in France, and by the Civil Aviation Authorities in Norway and Belgium. In France, the Service Technique de la Navigation Aerienne has bought a number of the multi-channel recorders, ranging from 8-channel, 11•" tape to 32-channel, 1" tape versions, with which to re-equip the Centres de Controle Regional at Aix en Provence and Toulouse in addition to the new airport at Lyon and the existing airports at Marseilles, Nice, St. Etienn~, and Clermont Ferrand. Airports in former French colonies are also being equipped with Racal's ICR's through purchases made

by ASECNA {Agence pour la Securite de la Navigation Aerienne en Afrique et a la Malagasy). Under the terms of this contract Senegal, Chad, Niger Republic, Malagasy, and Cameroon, are added to the list of countries using this uipment. In Norway and Begium, the orders total 25 re~~rders, embracing all ver~ion~ ~f t~e equ!pment, in addition to ancillaries such as time mJect1on units, reproducers, etc.

Racal-Milgo Limited have won two orders to supply modems for the radar data network associated with the ATC system for the U. K. The two main ATC centres at West Drayton and Prestwick, and the sub-centre at Manchester, will constantly receive information on aircraft identity, range, azimuth and height from nine remote plot extracted radar sites. At these sites the original analogue data from both primary and secondary surveillance radars is converted into digital form for transmission to the central proessors over Post Office telephone channels using Racal~ilgo modems 5500/96 operating ~t 9~00 bits ~er ~econd.

The modems include fully automatic lme equalisation and a multi-part facility enabling up to four channels of data to be handled simultaneously. In the CAA system dual channel modems are used, one channel carrying radar data at 1200 bits per second and the other handling remote monitoring information at 2400 bits per second. The first modems delivered against these contracts will be in use by the end of this year between Burrington (Devon) and West Drayton.

Book Review Fair-Weather Flying by Richard L. Taylor, published by MacMillan Publishing Company Inc., 866 Third Ave., New York, N. Y. 10022, 1974, 299 pages, $ 7.95, illustrated and indexed.

"Twelve Ways to Drive Tower Controllers Up Their Glass Walls" is the intriguing title of one chapter in this highly readable and thoroughly up-to-date textbook on VFR flight operations. This chapter, along with another called "How to Chicken Out in Front of Your Friends When the Weather is Lousy" should prevent a lot of boo-boos by neophyte pilots, and thereby save air traffic controllers a lot of headaches in the future.

Other chapters cover such subjects as ADF navigation, night flying, crosswind, short-field and twin-engine operations. The twin-engine chapter carries the somewhat startling reminder that the toss in climb rate, in light twin-engine with one engine out, varies from 69 percent in the Mitsubishi Mu-2 and the Rockwell Commander 690 A, up to 90 percent in the Piper Seneca.

The author of Fair-Weather Flying is an assistant professor in Ohio State University's Department of Aviation; the object of the book is to show other pilots how to get the most out of their airplanes, for their own enjoyment and safety.

Each chapter is complete in itself, so readers can start anywhere in the book and read the chapters in any order.

The text is practical rather than scholarly, and is liberally sprinkled with anecdotes and humor. A complete index adds to the usefulness of this book as a handy reference.

Although new pilots would probably get the most out of this book, we would recommend it highly to all who fly for the pure joy of flying.

Tirey K. Vickers

49

Accident Investigation Report Mishap With A Moral A four-engined, turbo-prop airliner with two crew members and seventeen passengers aboard was on an IFR flight to an island destination. Weather in the area was characterised by low cloud and moderate to heavy rain showers associated with an approaching cold front. They were m~intaining a westerly heading on Airways at 4,000 feet. Near the destination airport, the pilot was instructed to contact Approach Control.

The controller advised the pilot that he was in radar contact and gave him a radar po~i~ion thre~ miles east of the second intersection. This pos1t1on was in error by approximately ten miles, but it was not questioned by the crew. Another controller, observing the handoff, noticed the error but considered it a "slip of the tongue" since there was no target three miles east of the second intersection.

The controller then gave the pilot a heading of 250 degrees and advised that the approach would be a radar vecto~ to ILS final approach, landing runway 07. The crew 4,000 and ack n o wledged by stating "Okay, will maintain ,, we're turning to a heading of 250 degrees . One minute later, Approach Control cleared the flight to descend to 3,000 feet. The crew acknowledged.

After this, the controller became busy with other traffic and there were no communications between Approach Control and the aircrew for a period of 4 minutes and 5 seconds. Then the crew requested further de~cent. The conroller advised them to turn left to a heading of 220 degrees and maintain 3,000 feet. ~he crew ackno~ledge~ and read back both heading and altitude. Later, during an interview the controller stated that at this time he had lost rada~ contact with the flight in an area of precipitation and the h ading was intended as an identification turn. Another contr~ller, who was acting as co-ordinator, directed the controller to bring the aircraft back to the north, and the following transmission was imme~iately ma~e: ¡:(Aircr~ft callsign), turn back right now, heading of ~80: Neither this transmission, nor any subsequent transm1ss1on, was acknowledged by the aircrew. The wreckage was located the next day by an aircraft flown o~er a track recons~ructed from recorded clearance instructions and vectors given to the missing airliner. It was located in an area of mountainous terrain with peak elevations ¡over 3,500 feet. The aircraft was destroyed by impact and there were no survivors.

The investigation of this accident revealed no evidence of equipment failure in the .aircraft or . Appr?ac~ Control facility. Therefore, the majority of the investigative effort was directed toward the human aspects involved.

Analysis of the aircraft's flight path showed that the crew had followed given instructions to the letter until the crash. The controller handling the flight had been employed by his Administration for approximately ten years prior to the accident, and had been a qualified radar controller for several years. However, he had recently been transferred to the facility in which he was working at the time of the accident. He, with his wife and four children (ages 8, 6, 5 and 3), had been living in temporary quarters for more than two months. His household goods had not 50

been delivered due to a strike by the shipping company involved and he had no way of knowing when they would arrive.

After the accident, members of the investigating team visited the controller's quarters. They found an unfurnished house with a borrowed refrigerator, some card tables and chairs, and cots for the children. The sleeping arrangements in the main bedroom consisted of two bunk-type mattrasses on the floor.

The Board of Investigation made a careful study of the other transmissions made during the four minutes and five seconds when there had been no communications between the aircrew and Approach Control, before the final instruction by the controller for a turn back to the north-west.

During this time, the controller was found to have been responsible for five separate aircraft. He had made 18 and had received 19 transmissions, or about one transmission every six seconds. During the last 25 seconds of this period, he had been told twice by another airline crew that somebody was interfering on the frequency of his transmissions.

The source of the interference was discovered to be another controller within the Approach Control facility.

In the light of these facts, the Board concluded that environmental and personal factors beyond his control lowered the controller's performance capability to the extent that he could no longer safely handle a heavy workload.

They determined that the probable cause of the accident was: " ... Vectoring of the aircraft into mountainous terrain under IFR conditions without adequate obstruction-clearance altitude by a controller who, for reasons beyond his control, was performing beyond the safe limits of his performance capability ..."

(MAC FLYER)

Brief News Items Control of Air Routes to North Sea Oil Rigs In "Air way", the monthly publication of Britain's Civil Aviation Authority, Air Marshall lvor Broom, Controller, NATS, gives some more details of the unusual problems encountered, and says: "Air Traffic Control conjures up visions of controllers using sophisticated computerised radar information to facilitate the rapid and orderly flow of traffic along the airways between the major airports. But life is not always like that.

There are very few modern aids to assist the safe separation of aircraft at low level over the North Sea. Today there are some 65 to 70 oil rigs and production platforms in the North Sea, and approximately 250 flights daily by British based helicopters alone provide one of the links between these and the shore. They fly at distances beyond the low level cover of coastal radar stations and sometimes too low to maintain radio contact with ATC. But they are not alone in this area.

The strike and air defence aircraft of the Royal Air Force, Royal Navy and USAF carry out the bulk of their low level high speed tactical training over the sea. With military aircraft flying at 500 ft and below at speeds of up to 600 knots and helicopters transitting the area in all weathers, the NATS mandate to serve all types of aviation has been severely tested. What are we doing about it?

Trial procedures were introduced in the East Anglian area on July 1 1974, after over a year of intense negotiations with the civil and military interests. The helicopters will keep to corridors in the height bands 750 ft to 2500 ft and the military will fly either underneath the corridors or over the top unless they receive prior clearance to penetrate them. When the cloudbase drops below 1500 ft and/or visibility deteriorates below 3 miles, the military will cease low flying and leave the low level area to the helicopters. co-ordination procedures are being arranged between the radar station at Neatishead, the military airfields, and the helicopter base at North Denes, to implement the agreed procedures. There are many important points of detail which I do not have space to describe.

Different problems exist off the Shetlands. The rigs are further from the coast and as they are in the exploration areas are constantly being moved. The national concession areas and FIR boundaries do not coincide so there are foreign rigs in our airspace and vice-versa. Can we devise procedures for safe civil and military operations in this area below radar cover? Do we require a special low level co-ordination cell in Scotland, with HF/RT communications?

We are busily engaged chairing a working party of civil and military interests and will, I hope, come up with the answers. Ideas are welcome."

News from Eurocontrol The Permanent Commission of Eurocontrol, the European Organisation for the Safety of Air Navigation, held its 44th Session in Brussels recently at the level of the Ministers' Alternates. The session was presided over by Mr. H. Raben, Director General of Civil Aviation of the Netherlands.

The session had been called to consider the application made by Portugal for studying the possible accession to the Eurocontrol Convention of 13th December 1960. The permanent Commission requested the Eurocontrol Air Traffic services Agency to undertake a detailed study of all the implications of such an accession and to submit the study to an early session of the Permanent Commission, if possible at its autumn 1975 session. For the initial phase the Permanent Commission approved the conclusion of an association agreement between Portugal and Eurocontrol and authorised the Agency to negotiate such an agreement with the Portuguese authorities. on another topic: among five proposals for action to establish a European data-handling policy, the Commission has forwarded to the Council of Ministers a project called "Real-time data-processing system required for Air Traffic control in the 1980s". If the proposal is adopted it will result in a feasibility study starting this summer which is expected to take 18 months to complete.

The Commission considers that study of the problem at European level should result in savings when the next generation of ATC equipment is developed. Air Traffic Control offers the most advanced data-processing applications and participation in the study would benefit the industry.

The market for ATC data-processing systems is valued at some $ 100 million annually. Depending on the result of the study, the Council of Ministers will decide whether to embark on a joint development phase which would last for up to 15 years. Installation of the equipment would be the responsibility of national authorities or of Eurocontrol, whose main area of interest is the upper airspace.

Eleven Commandments for Safe Flying 1. Pity the poor controller, for his troubles are many and the transgressions against him number unto the thousands, yea verily even unto millions.

2. Therefore, show thy mercy unto him for he is sorely tried. He acteth as guardian angel to poor misguided birdmen, and in return receiveth harsh words, unkind looks and hath all kinds of evil happenings bestowed upon him.

3. His every act is guided by the book known as Manops and should he transgress therefrom even to the extent of, lo, one misapplied portion of phraseology, all hands revile him and make light of his prowess.

4. Therefore, I say unto you, honour the poor controller lest he turn thee on final for 07 while clearing another for takeoff on 25.

5. Turn from thy appointed way hurriedly when instructed by him, lest thou find thy propeller making merry with thy fellow birdman's empennage, for the controller seeth things which thou cannot, yea, verily even in thy wildest dreams.

6. When the controller sayeth unto thee, with the voice of urgency, "Hold", hold thou with the greatest expediency and without argument lest this be the last time that thou holdest.

7. Should the voice from the air, which is the controller's, clear thee for takeoff, go thou like the wind, for perchance there may be a machine of flight on a short base which planneth to use the very surface upon which thou sitteth in a very short while, yea verily even unto seconds.

8. Should conditions surounding thee be that which is called "IFR", ask him not for "VFR" takeoff, for should he allow it he will find himself in sore trouble with the agency known as Air Regs and the law of the land adjudgeth harsh penalities upon these happenings.

9. Speak to him with a voice of honey. Treat him as a brother lest he becometh excited, looseth his wits and giveth thee a right turn out when a left turn befitteth the occasion, for lo, he loveth a calm and courteous pilot above all things.

10. When thou hearest the words from the little black box saying "unable to approve account traffic", beseech him not from thy lofty position to change his decision, for lo, had not the traffic been there the words would not have been spoken, for he hath the eyes of an eagle and his view of the traffic pattern is unrestricted.

11. Watch thou closely for all four wheeled vehicles, for they are numerous and their actions are unpredictable, even as the whirlwind. Treat them with fear and respect while taxiing, lest they charge upon thee with the speed of a lion and the fury of the tornado, for their drivers may be uninstructed in the ways of the birdman.

Remember these commandments and heed them well, for if thou wilt not, aircraft thou will not need to fly, for wings and the harp (CATCA Journal) shall transport thee.

51

New Training Films

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Area Navigation ICAO 568 Although this film was originally produced for the U. S. Federal Aviation's (FAA) own use, air traffic controllers and pilots will find it useful to understand better the area navigation concept and particularly its advantages in helping to expedite Air Traffic Control.

The film makes use of animation to demonstrate effectively, among other things, how "way points" are established to permit direct routes to be set up between any two given points. Examples of how to operate RNAV equipment are also shown. Types of RNAV equipment, RNAV transponders, parallel airways, and many other aspects of area navigation are considered.

28 minutes U.S. $ 160.00 Colour

Airport Chicago O'Hare Santa Ana, Calif.

Van Nuys, Calif.

Long Beach, Calif.

Atlanta Los Angeles Torrance, Calif.

Opa Locka, Fla. San Jose, Calif.

Phoenix, Ariz.

Plane move.

680,763 615,446 582,853 546,762 502,264 465,721 428,273 419,736 406,830 404,868

Gen. aviation °/o (1) 15.1 95.5 99.4 96.3 15.8 23.8 99.9 97.3 87.6 76.9 (2)

(1) Note that general aviation is the majority at seven of the ten. This includes air taxis, which FAA counts as general aviation.

(2) Phoenix ranked 20 in fiscal year 1973.

General aviation, including air taxis, recorded 78.4 % of total traffic handled by 396 control towers. Instrument operations showed general aviation totalling 44 % of all IFR movements, compared with airlines' 39 O/o, probably first time general aviation has surpassed airlines in this category. Note that last paragraph: general aviation has now surpassed those wondrous airlines in instrument operations! It will be interesting to see how the airline industry puts us down now ...

Meteorological Reports for Aircraft Landing ICAO 528 Produced as a training aid for pilots, air traffic controllers, flight operations officers and meteorological observers, this film may also be used in high schools and colleges.

It stresses the importance of prompt and accurate weather reports - particularly under marginal MET conditions - since the safety and economics of commercial aviation depend heavily on the accuracy of observations made by the trained MET observer. The need for specie..:.; weather data prior to landing, the main elements of a MET report for landing, how the MET observer obtains data for his report, and how the report is relayed to Air Traffic Control for transmission to the pilot are shown.

21 112 minutes U.S. $ 125.00 Colour Both films may be ordered directly from: ICAO Distribution Office, 1080 University Street, Montreal 101, P. Q., Canada.

Max Karant, Senior Vice President, Aircraft Owners and Pilots Association, Washington, D. C.

The Editor has replied as follows: Dear Mr. Karant, Than your for letting me have the most recent resume of air traffic activity In the U.S. Our February issue was printed before the 1974 figures were In our hands, and, admittedly, the 1973 figures do appear out of date In a magazine which comes out In 1975.

The figures which you provide show a clear outline of the important part which general aviation plays not only In aviation but also in a nation's economy, and I'm afraid that too many controllers - working as they do In an environment which clearly favours the airline industry - too often seem to lose sight of general aviation's vital role. It was therefore good to see the emphasis which general aviation received at the 1974 Convention and Exhibition of the British Guild of Air Traffic Control Officers in Bournemouth, and I aim at presenting a balanced picture of both airline Industry and general aviation topics related to A.T.C. In THE CONTROLLER.

Letters from ReadeES Dear Sir, Your resume of air traffic activity in the U.S. on page 8 of your February issue is a little out of date. Data for the ten busiest airports in the U.S. for the fiscal year 1974 are as follows:

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52

Corporation Members of the International Federation of Air Traffic Controllers' Associations AEG-Telefunken, Ulm/Donau, Germany Air Vision Industries, Inc., Montreal, Canada ASS MANN GMBH, Bad Homburg v. d. H., Germany CAE Electronics Ltd., Montreal, Quebec, Canada Cossor Radar and Electronics Limited, Harlow, England Dansk lmpulsfysik A. S., Holte, Denmark Ferranti Limited, Bracknell, Berks., England Glen A. Gilbert & Associates, Washington D. C., U.S.A. Ground Aid Group, Esbjerg, Denmark International Air Carrier Association Geneva, Switzerland International Aeradio Limited, Southall, Middlesex, England Jeppesen & Co. GmbH., Frankfurt, Germany Lockheed Electronics Company, Inc., Plainfield, N. J., U.S.A. The Marconi Radar Systems Limited, Chelmsford, Essex, England N. V. Hollandse Signaalapparaten, Hengelo, Netherlands The Plessey Company Limited, Weybridge, Surrey, England Racal-Thermionic Limited, Southampton, England Selenia - lndustrie Elettroniche Associate S. p. A. Rome, Italy Software Sciences Ltd., Farnborough, Hampshire, England Space Research Corporation, Inc. Quebec, Canada The Solartron Electronic Group Limited, Farnborough, Hants., England Stansaab Elektronik AB, Jarfalla, Sweden Thomson - CSF, Paris, France 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 "The Controller" is offered as a platform for the discussion of technical and procedural developments in the field of air traffic control.

selenia airport and • traffic control systems air

Selenia offe rs adva nced equipment for Ai r Traffic Control including : • RA DARS • B ROAD BAN D AND NARROW BAND LINKS • D IG ITAL DI SPLAY SUBSYSTEM S • COMPU TERS • PRIMARY AND SECONDARY RADAR EXTRACTORS • S IM ULATORS AN D DIGITAL INTER FACE EQUI PMENT 0 AUTOMA TED A IRPORT SUBSY STEM S as w ell as " COM PLETE AIRPORT TURN-KEY PROJ ECTS

tog eth er w ith w ide experi ence in : • SYSTEM DES IGN • SY STEM IMPLEMENTATION AND INTEGRATION • LOGI STIC SUPPORT

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INDUSTRI E ELETTRONI CHE A SSOCIA TE SpA. CIVIL RADAR AND SYSTEMS DIVISION Via Tlburllna Km 12.400 - 001 31 Rome, Italy Cables : Selenla Roma Tel ex : 61106 Sel enlat Phone: 43601