IFATCA The Controller - 2nd Quarter 1988

ISSN 0010-8073

JOURNAL

OF AIR

TRAFFIC

CONTROL

2 / 88

IN TH IS ISS UI:: CONFLICT DETl:CT ION GLOBAL ATC SY STEM HIGH BLOOD PRESSURE MODERNIZED ATC IN EGYPT SYSTEM CAPACITY AND AIRCRAFT DESIGN HOTOL GENEVA , SWITZERLAND

2lild QUARTER 1988

VO LUME 27

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Tosee Australia, you have to hop.

If vou fh· to :\ustra li.1 \,·ith most airlines, rnu 'II onh sec ,l sn,-all pa;t ot'thc country. The part they lan'd in and · take off from . Th at's usualh · just SH lnc, or .\klhournc.

But when _v ou fly to Austra lia \Yith Qa nta s, you can hop from one side of' the countn to the other an d sec so muc h more. · Beca use (.2._ antas (and on h (.2._antas)take off and land in eight diffrre nt part s of Australia.

So nm,· _rnu can \·isit so me of the best holida\ spots

Australia has to offer, includin g;Sydney, Me lbourne Brisbane , Perth, Adelaide, 'fowns\ ilk , Cairns and f) ·in .

For instance, }OU can tly into Perth, hop across ;o ' 111 Sydney on Q_antas , then up to Brisba ne and fl, honi . .. . 'II a Iso mai,;c 1. qurtc , a sarn1g , on the cost . cit· C. 1I 0 111 there. 'rou . . · · \ OU r domestic arr/arc. · So if you plan to go to Austra lia, sec as much . .. ·1 . · an d p Ian your tnp · hop by hop. as ·\ou can. , ·''.1"1.to ()z,1,ntas I he, don t ha\ ·c a bn !!,'arnoon thcr r J)l1ncs 1·<J 1- not h.rng.

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THE AUSTRALIAN AIRLINE

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IFATCA JOURNAL

OF AIR TRAFFIC CONTROL

THE CONTROLLER Volume 27 · No. 2

Geneva, Switzerland, June, 1988

Publisher International Federation of Air Traffic Controllers · Assoc iatio ns. P.O . Box 196 . CH-12 15 Geneva 15 Airport . Switzerland Officers of IFATCA E.F. Sermijn . President and Chief Executive Officer .

U. W indt. Exec utiv e Vice-P resident Administrat ion .

T. Gustavsson. Exec utive Vice- President Finance.

W . Rooseman. Exec utive Vice-President Professional.

R.W . Randa ll. Execu tive Vice-President Technica l.

P. O' Doherty . Exec utiv e Secretary Editor H. Harri Hensc hler 1998 Glenmore Avenue. Sherwood Park.

Alb erta. Canada. TBA OX8 Telephone (403) 467 -6826 Management and Advertising Sales Office The Controller . P.O. Box 196 .

CH-1215 Geneva 15 Ai rport. Switze rland H.U. Heim. Subscrip tions and Publicity .

Tel. (022) 82 26 79 M . Henchoz. Accounting. Tel. (022) 92 56 82 B. Laydevant . Sales Promot ion . Tel. (022) 82 79 83 Printing House ' Der Sund'. Verlag und Druckerei AG Effinge rstrasse 1. CH-300 1 Bern.

Telepho ne (03 1) 25 12 11 Subscriptions and Advertising Payments to: Unio n Bank of Switze rland. Airport Branch CH-12 15 Geneva 15 Airpo rt. Switzer land Acco unt : IFATCA/The Contro ller No . 602 254 .MD L Subsc ripti on Rate: SFrs. 20.- per annum (4 issues). plu s postage and package : Surfacemai l: Europe and Med iterranean co untri es SFrs. 4.20. other countries SFrs. 5 .4 0 .

Airm ail: Europe and Mediterranean co untri es SFrs. 6 . 20. ot her cou ntr ies SFrs. 10 .60.

Specia l subscript ion rate for Air Traffic Contro llers.

Contributors are expressing their persona_l points_ot view and opinions. which may not necessarily coincide with th ose of the Internat ional Federation of Air Trattic Contro llers· Associations (IFATCA).

IFATCA does not assume responsibilit y for state ments made and opinio ns expressed. it does only accep t respo nsibility for publi shing these co ntribution s.

Contributions are we lcome as are co mments and criticism . No payment ca n be made tor man~scripts submitt ed for publica tion in "The Controll er . The Editor reserves the right to make any editori al_ changes in manuscrip ts. w hich he believes w ill im prove the mate rial wit hout altering the intended meaning .

Wri tt en permissi on by the Editor is necessary for reprintin g any part of this Journal.

Advertisers in this issue Oanta s. Phili ps. Thomson-CSF .

Cossor. Air Canada. Seleni a Photos Selen ia. Phili ps. Classic Air. _ Sofreavia . Cossor . Piaggio. RheinM ain Airport. BAe THE CONTROLLER/ JUNE 1988

In this issue Conflict Detectio n

page

4

Global ATC System

page

8

High Blood Pressure

page 12

Mod ernization of ATC in Egypt

page 15

Intera ct ion between System Capacity and Aircraft Design

page 28

HOTOL

page 31

tive which 1s not always easily attained .

All Edito rs have relied. of course. on a great number of other volunteers who cont ributed to the continued existence of 'The Control ler· . from member s of the Editor's Commi tt ee through Manag ing Editors and the present · Controller Managemen t Group· to the printing house . Al l these must be included in the expression of appreciation .

From the Editor The present issue of 'The Contr oller·. number 2 of 1988 . is edition onehundred of the magazine . although is is the seco nd issue of Volume 2 7 . Thi s is explained by the fact th at in 1971 (Volume 10 ) three magazine issues were printed . in 1972 there was one comb ined issue for the year. and 197 3 saw two issues.

Prior to these years. since Volume 1. issue 1. in lat e 1961 / early 1962 th e regul ar four issues per ann um appeared - as has been the case aga in since 197 4 .

Ref lecti ng on copy 100 of t he IFATCA Jo urnal of Air Traffic Control one ca nnot help but to look back w ith app reciat ion to th e individua ls who. over the years. vo lunteered to ens ure that 'The Controll er' was editorially sound and wou ld be printed . whenever possible. on a t imely basis.

This apprec iation is dir ected to th e magazine's fir st Editor . also it s longest-serving. Walter Endli ch ( 196119 7 2 ). and his success ors Ge de Boer (1973- 1976) . Brian J ones ( 197 7/ 78) and Andreas Avgou sti s ( 19791985 ). They all offered ded icate d and untirin g service to our magazine wh ic h . beca use of its very nature and diver se reader ship . endeavors to be mo st things to mo st people . an objec-

Than ks must also go to IFATCA 's Corporat e Member s who contribute artic les and . through the ir adverti sement s. help ensu re t he magazine ' s finan cia l viabilit y . the readers who offer encouragement and adv ice . the IFATCA off icers and the great number of other contributors . and t he aviation authorities who provide information and. as has Transport Canada. have assisted in enab ling the Editor' s required attendance at meetings .

Being a vo lunteer Editor during one ' s free time is a cha llenging and complex task. However . with the con tinued assistance of all who are int erested. involved and supporti ve I am certain that. some twenty -five year s from now . issue 200 will be successfully celebr ated.

H. Harri Hensc hler

In 1987, Schiphol and Changi were again chosen as the 'best airports in the world' by three independent surveys.

Philips compliments them on their well-earned achievement, and complements their excellent facilities with a wide range of high technology.

For Schiphol Amsterdam, the airport authority has developed an ambitious U.S. $700 million expansion project. ¡ By the mid-90s Schiphol will be capable of an annual traffic throughput of up to 25 million passengers and over 1 million tonnes of cargo.

Philips is helping with energy-efficient terminal lighting, new-generation nonglare apron floodlighting and many other technical aspects of this massive project.

We have also been commissioned to implement the first international CIDIN (Common ICAO Data Interchange Network) node as a modernization of the existing AEROPPmessage switching system for the worldwide Aeronautical Fixed Telecommunications Network, AFIN.

For Singapore's Changi International Airport, we supp lied its long -range ATCand airport surface detection radars, outdoor lighting and the public address systems in Terminal I, while the new Terminal II will be equipped w ith Philips technolog y to a combined value of some U.S. $ 15 million.

This includes public address , CCTV and energ y-efficient lighting as well as a computerized Flight Information Display System (FIDSII) that will integrate the flow of data among the public, administration and op erational areas of the terminal and display the right information, in the right format , at the right place.

A Philips AEROPPsystem helps Singapore to play a key role as a regional AFfN node. , From technical systems to profession al services, Philips complements the needs of airports the world over. [ Philips. The sure sign of expertise worldwide .

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Can Computers Take over Conflict Detection from Controllers?

S. Ratcliffe *

Introducti on Air traffic control is dominated by t he demand for very high levels of safety. In busy airspace , this is ach ieved by a large force of controllers supported by a considerable quantity of electronic equipment which is expensive to procure and maintain . To allow rising levels of traffic to use a fixed volume of airspace requires a more than proportional increase in numbers of contro llers, and the current rapid growth in computer technol ogy leads to questions about the possibil ity of ' automating ' the ATC process. Automated data processing is already spreading through ATC, and, although t he consequences do not seem to have attracted wide discussion, such data processors are beginning to encroach on decisiontaking t asks, e.g. the inte rpretation of radar data, that was once the prerogative of human con trollers.

Advanced Automation The FAA's Advanced Automation Program is perhaps the most ambitious long-term plan for ATC, and also t he most fu lly described in documents available to the public. In the m id-19 70s, the FAA were investigating the prospects of greater levels of ATC auto mat ion intended to lead to greater product ivity by the controllers and to improv ed , fuel-efficien t, flight trajectories. By 1979, FAA confi dence in the prospects for automation resulted in t he deve lopme nt of the AERA [1] conce pt for a highly automated en-route ATC system, in which all t ime-cr itica l ATC decisions in enroute and tra nsiti on sector s would be made by comp uters . A sma ll number of human ·system managers ' would ensure, by some mechanism not too close ly def ined , that the ATC system was correct ly perform ing its function.

• The author is an air traffic control consultant at 2 Mason Close, Malvern , WR14 2 NF, England . hhh 4

failure to detect the problem in time will render the resolution mechanism irrelevant .

Existing Conflict Alert Systems

Several present-day ATC data-processing systems include an automatic conflict-alert mechanism, based on radar data. Such systems are intended to support the human controllers , not to replace them . With Mode A/C SSR, imperfections in the radar data set a limit to the accuracy with which conflict can be predicted. By heavy smooth ing of the radar data, and/ or invoking the flight plan to assist the prediction, greater prec ision is possible , but the validity of the forecast now depends on the implied assumpS. Ratcliffe tions that there will be no departure from the planned trajectory, that is, The system manager would also be tha~ there will be no events of the type required to intervene in the operation which radar and the conflict-alert when it was necessary to handle mechanism is meant to detect . ·exceptions ' . The FAA has rejected In practice , _thereis a second major most of the arguments [2] critical of source of pred1ct1on error , in addition the AERA proposal . A 1987 paper [3] to the radar difficulties mentioned which speaks of ' more and more of the above . To avoid ~ conflict, ATC may cognitive aspects of ATC migrating have imposed l1m1tations on the vertifrom the controller to the ATC com- cal trajectory of aircraft wishing to puter' makes it clear that the AERA climb or descend . Unless the control concept is still adhered to as a long- ler _has made use of some input device term objective. to inform the computer of his rev·IsIon · One possible, relatively small, to the clearance , the conflict alert will initial step in the direction planned for go on to warn the controller of h AERA, is a mechanism which detects , c_on_flict' wh_ic~he h~s been carefui e eliminate . Similarly, It will fail tow to and resolves threatened conflicts between aircraft under ATC jurisdic- the controller of any danger resultrn tio n and arising from some unfore seen from his amendment to the plan . ng event leading to an early risk of colMore accurate and reliable SSR lision . In such a situation. time is e~u1pment, based on Mode S, will pressing and t he need is for a simple bring . a c~n_s1derable_reduction in immediate solution to a problem in errors in posItIon data , in mi ssing plots which the collision threat dominate s d~e _ to gar_ble a_nd in errors in transany cons ideration s of efficient flight mIssIon of 1dent1tyand height . Similar profiles or longer-term strategy . If safe benefits outside . radar coverage solut ion s ca n be devised by computer, should follow the introdu ction of the the case for automation can be quite dependent surveillance schemes strong. The present paper proposes to under study by ICAO FANS . The address t he safety issue in such an resulting capabi lity to exchange autoautomated system. The emphasis will matically data between ATC and airbe on co nflic t detection, since any craft could make available within the THE CONTROLLER/ JU NE 1988

computer system. without controller assistance. an accurate current picture of the planned trajectory of all controlled aircraft.

Highly Automated Conflict Alert Systems If. as the AERA proposal apparently intends. the eventual object is to provide a system in which human controllers are not generally required to involve themselves in the activity of individual aircraft. the automatic conflict detection system now becomes the main line of defense against collision. A limited controller workforce can. it is argued. deal with any extraordinary situations that are beyond the capability of the software. provided. presumably. that there is some mechanism to alert them to this situation when it arises.

It is a relatively simple matter to define a set of rules for detecting failure to satisfy horizontal or vertical separation standards. Rules which recognize the point at which remedial action should be initiated are much more complex and must be tailored to fit the existing data sources. the traffic environment and local ATC practices.

The problems of formulating alarm criteria will not be discussed in the present paper. which is concerned with the subsequent problem of validating the rules when they are first formulated or subsequently amended.

Despite an appreciable false-alarm rate. there are conflict-alert systems which give satisfactory service when used to back up the human controllers. Of course. in this mode of operation. a system which detected no more than. say. 50% of a controller's rare oversights would make a considerable contribution to safety. If an automated system is to replace. rather than to back up. the human controllers. it will clearly be required to detect a much larger percentage of all conflicts.

The writer is not aware of any detailed safety study that estimates the contribution made by radar-based detection of conflicts to safety in flight. or which estimates the target level of safety that should be achieve~ in the detection process. An approximate target figure is perhaps suggested by the reliability requirement for the area control computer cou~ler in the FAA' s Advanced Automation System [4]. This requires the reduced capacity mode of the system to be available 99.9999% of the time. and for the present discussion it will be assumed that an analogous level of reliability is required from the aut~matic conflict detector. that is. that 1t THE CONTROLLER/JUNE 1988

should not fail to give adequate warning more often than once in a million encounters.

If aircraft carry an airborne collision avoidance (ACAS)system. this can act as a further defense against collision.

An FAA safety study analysis of Minimum TCAS II [5] concluded that. if all intruding aircraft were equipped with SSR Mode C. the number of near midair collisions involving civil air transport aircraft operating under IFR would be reduced by a factor of about 20. It would be dangerous to assume. however. that many dangerous situations that have escaped the elaborate ground-based detection logic can be necessarily trapped by an ACAS system. such as TCAS II. having strictly limited data on range and height and no knowledge of the environment in which the aircraft are currently operating. For this reason. it is proposed to treat any airborne collision avoidance mechanism. such as ACAS or pilot vision. as part of the conflict detection mechanism to be evaluated. recognizing that any failure in the ground based system may possibly be detected by these other means.

Validation of Conflict Detection Mechanisms As explained above. TCAS II uses much simpler logic than would be necessary to perform the functions of a human controller. and the safety level needed to give a worthwhile service is probably many thousands of times lower than that needed in ·automatic ATC'. Nevertheless TCAS logic is of interest because. even after at least ten years· study. modifications are still being found to be desirable.

Almost all the theoretical studies of TCAS. in the USA and elsewhere. on which the logic is based. have been concerned with pairs of aircraft in straight-line flight. This is. of course. the most common situation. but flight in TMAs. for example. involves many heading changes. Limited study of an encounter between one aircraft flying in a straight line and another flying in a circle [6] shows that. under such conditions. the TCAS logic may give an appreciably reduced time for escape.

The theoretical design for TCAS was followed by airborne trials under controlled conditions. using FAA aircraft and pilots. and subsequently by flights using the equipment in a commercial air transport aircraft in normal operation. The FAA. understandably. approached this latter stage with considerable caution. such a trial is by no means a formality.

Several ATC authorities now

include in their data-processing systems a conflict-alert facility such as the French 'filet de sauvegarde' (safety net) logic to serve as an aidememoire to controllers. Reference 7 stressed the absolute necessity of designing this system to work with imperfect radar data. and it had to be validated under realistic conditions. with real radar data from actual traffic.

The introduction of a fully automatic conflict alert would. no doubt. need a period during which human controllers and the automatic system operated side by side until sufficient confidence had been developed.

Given the one-in-a-million criterion suggested earlier. the process would necessarily be a protracted one. There is even a danger that the controllers might come too quickly to trust the machine logic. so that they eventually failed to take a sufficiently suspicious view of the machine activities. The protracted period of study involved before such a system could be validated is a drawback not only when the automatic system is first introduced into service. but also whenever there are changes in the rules for the use of the airspace in question. Such modifications are relatively common. and can arise with the introduction of new aircraft types (often with a novel avionics fit). or with changes in the route structure reflecting the traffic demand. In the UK alone there are about 100 NOTAMs per year which involve changes. great or small. in the way airspace is to be used.

It seems clear that an essential preliminary to the introduction of automatic conflict resolution must be the evolution of tools for the off-line testing of conflict detection logic.

Such tools are not likely to eliminate the need for close supervision of the operation of any new software. but they may. in time. considerably accelerate the process. One method. that is almost invariably used to test some new software or other ATC aid before its introduction into service. is to expose it to various samples of simulated 'typical' traffic. A potential weakness of these tests is that a problem may be overlooked both in the design of the system and in subsequent simulations.

It is suggested that one test to be applied to the conflict detection algorithms should be based on a worst-case assumption. that an aircraft may inadvertently embark on some unexpected maneuver that. in accordance with 'Murphy's Law·*. is due to bring the aircraft into collision.

• 'Murphy's Law· states that anything that can go wrong. will do so at the worst possible time.

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perhaps without adequate warning from the conflict alert logic. It may be unduly pessimistic to assume that a pair of proximate aircraft will simultaneously embark on a course of Murphy-like behavior , but an encounter involving one aberrant aircraft should c learly be adequately covered by the alarm logic.

It is proposed, therefore, that the test should consider in turn a variety of aircraft, each behaving in a perfectly reasonable manner and faced by a second aircraft, the 'threat', which, within the bounds of velocity and accelerati on appropriate to the airspace under discussion , is attempting t o bring about a collision with the least possible warning. As reference 6 suggests, a conflict warning may commence and be later cancelled whilst the aircraft continue on a collisio n course. We require that the co nflict logic should give, in adequate tim e, a warni ng that persists up to the moment of collision.

Mathematic al techniques exist for finding the threat trajectory that minimi zes t he time duration of the final warn ing before impact. Many of the se have been devised in the course of studies of aerial combat problems [8] in w hich one aircraft seeks to maximi ze its chances of intercepting a target which, in turn , is attempting to minimiz e the same probability. The present pape r is concerned only with the onset of collision warning, and up to this point we assume that the t hreatened aircr aft is behaving normally, so that t he m at hematical problem should be app reciably simpler than when discuss ing pursuit and evas ion. It should be possib le to use similar to ols to study the conflict-resolution prob lem, altho ugh the present wr iter has not examined t his t opic .

Conclusion The history of ATC is centered on the steady growt h in the use of electronic too ls. If, in t he fut ure, computers are to play a st ill larger part. there are serious prob lems involving the reliab ility of com pute rs, data lin ks, and softwa re. Some of t hese problems are shared w it h co mpu ters in commerce. or in the control of aircraft flight or of the ope rat io n of nuclear reactors. ATC should therefore be ab le to exp loit ot her users' experience . The present paper has concentrated on a prob lem pecu liar to ATC, that of validating the algo rit hm s needed for an automatic short-term conf lict warning system , a small but critical part of the overa 11system.

The issue is not whether a ¡com puter' is to take over ATC tasks from 6

the controllers . Computers are mechanisms which apply a set of rules to identify situations with which they are faced, then using further rules to select and apply one of the problemsolving algorithms held in the computer repertoire . In relatively simple systems, these rules are explicitly based on a detailed description of each and every situation to be handled. In 'intelligent' systems, attempts are made to generalize the rules , in the hope of applying them in a range of environments . Both in present-day ATC and in the AERA proposal , humans are ultimately responsible for the control decisions , although there are considerable differences in the task of a controller, who must solve problems as they arise, and that of designers who must foresee all possible problems and lay down, in advance , rules for their solution .

There may well be considerable scope for software, external to the ATC system proper, to assist the software designers at many levels of their task.

Conference

The scheme here presented is perhaps the basis of one component of a software test package based on a healthy suspicion of all ATC innovations .

References 1. Goldmunz. L. et al. , Outline for AERA Concept Document, FAA Office of Systems Engineering Management. Dec. 1980 .

2. Wesson, R.. Scenarios for Evolution of ATC, Rand Corpn . R-2698-FA, Nov. 1981 .

3 . Hunt. V.R.. Zellweger, A ., Strategies for Future ATC Systems, Computer. Feb. 1987.

4 . Avizienis. A ., Ball, D.E., On the Achievement of a Highly Fault-Tolerant ATC System, Computer , Feb. 1987.

5. Mitre Corpn., System Safety Study of Minimum TCASII, MTR-83W24 1. DOT / FAA/TM-83/36 , Dec. 1983.

6. Ratcliffe. S. , Secondary Radar for Airborne Collision Avoidance , Journal of Navigation , Vol. 36 No. 3, Sept. 1983 .

7 . Printemps, A ., Conception franc;ais de la prevision des conflits : le filet de sauvegarde , International Conference on Electronic Systems and Navigati 'on Aid s, Paris, Nov. 1977.

8. Yavin, Y., Pachter , M., Pursuit-Evasion Differential Games, International Journal of Computers and Mathematics, Vol. 1 3 No .

1-3 . March 1987 _

Resol tio

IFATCA '88 The International Federation of Air Traffic Controllers' Associations, at its 27th Annual Conference, condemns in the strongest possible terms the recent hijacking of a Kuwait Airlines aircraft and the murder of two of its passengers.

The unwarranted interference with the safe passage of a civil aircraft, endangering the lives of passengers and crew cannot, in any circumstances, be condoned. The perpetrators of such foul acts of air piracy should, and must, be made to face the full rigours of civilized justice. The government authorities of all nations must ensure that there is no hiding place for such people. Only by these means will the commandeering of aircraft, and the consequent suffering of those on board be brought to an end.

High-pressure media coverage of such events, while providing the general public with an update on the hijack, serves only to glorify the perpetrators among their followers. IFATCA urges a more low-key approach to the reporting and general media coverage of such events.

THE CONTROLLER / JUNE 1988

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THE BRAINPOWER.

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Global ATC System P.A. Jorgensen and E. Di Giacomo, Selenia S.p.A.

Summary The rapid advance of new hardware and software technologies permits a new and more integrated approach to the very compl~x ~rea of air traffic control. The d1stnbuted intelligence architecture. pio~eered

by Selenia 7 to 8 years ago. 1s now generally used for the tactical part of the ATC system. The new hardware and software components open the door to a far more integrated system. where other elements of the air traffic system are included.

The areas to include in a global automation program are:

By which we mean a major system consisting of one or more ACCs. TMAs. TWRs. etc.

The main architectural building blocks are: Distributed Intelligence: Local Area Networks (LAN): - Packet Switching Network (PSN).

The concept of distributed intelligence satisfies the requirements for advanced system performance with fail safe/fail soft capabilities. using

multiprocessor computers with high configurability and remote and/ or local processing capability.

The Local Area Network (LAN) gives easy expandability in terms of processing nodes and work stations at the level of center and services (ACC. TMA, TWR. APP. Meteo. Supervision. etc.).

The Packet Switching Network (PSN) allows wide information distribution and integration over a national area. especially for non-real time services like FOP or AIS. The interconnections between subsystems are either via dedicated lines for real time data (mainly radar data and voice communication) and PSN ISO-OSI for any other data. The PSN International Standard Organization-Open System Interface is a data transmission system now being installed in many countries. The ISOOSI standard foresees a number of

Tactical Control Radar data processing Flight data processing A/G/ A voice switching Workstation automation Strategical Control Flow control - Flight planning - Apron control Services AFTN Meteo processing AIS Automated technical supervision Automated information distribution

P.S.N. PACKETSWITCHING NE'TWORK

Training

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Radar and FOP simulation Tower simulation

The following is a description of Selenia's system solution to this extremely complex task.

System Architecture A global approach to the automation of such a complex environment. incorporating many different areas of automation and using virtually all types of electronic technologies. requires an architectural structure which allows for a very wide system configuration spectrum. The research in Selenia points towards the use of ISO-OSI standards to ensure maximum system flexibility and future expandability. The working name for this system is SATCAS-4.

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TERMINALS

Figure 7

SATCAS-4 global architecture THE CONTROLLER/ JUNE 1988

different levels of connections between systems. ranging from the physical connection (electrical wires) to direct file transfers between computers.

Fig. 1 shows the global architecture of SATCAS-4 at its highest level of integration .

Hardware Elements The following hardware elements are employed in the system : Radar Sensors; ATC Center LAN based system; Airport LAN based system ; Radar site LAN based system; AIS LAN based system; Meteo Radars; Meteo LAN based system; AFTN LAN based system.

Selenia has made an immense effort to introduce a very high degree of communality between the various elements in the system. One of the most significant may be the use of the Selenia designed MARA computer throughout the system .

The MARA (Multiprocessor Architecture for Realtime Application) is based on the Intel 8086 / 286 chips . and is a multiprocessor system using up to 16 processors. with up to 0 .5 Mbyte on-board memory on each processor. each expandable with 2 Mbyte memory boards . The MARA is used as radar head processor. as multiradar processor. as flight plan processor. as built-in display processor. as AFTN processor and wherever there is a requirement for a powerful processor. Of the same family is the FDU-M. a single board processor used for less demanding roles. like Gateways. PAD' s. remote smart terminals. etc.

At the same time. the various types of radars demonstrate a very high level of communality . The same radar processor and computer is used in all radars . namely the VERA computer designed by Selenia especially as a very fast radar processor/ controller .

Standard RF-. IF-. and video circuits are used throughout in the radars.

Thi s high degree of communality is very important for several reasons .

Introdu ct ion of new functions is facilitated. new software modules are easily introduced . and as very little 'ta iloring ¡ is done from system to system. the various modules will run all systems. when installed. Selenia has here learned from experience. and from the experience from the world of PCs. Neither should the advantage from the point of view of logistic support be underestimated . A system. which employs only a very limited THE CONTROLLER/ JUNE 1988

number of various circuit boards is easy to mainta in. and has a very low life-cycle cost.

Radars A new class of radars has been studied . especially for unmanned operation. with full remote control of all parameters and BITE. using narrow band transmission of all data. inclusive of plots, tracks, weather data, radar and radar head processor remote control and radar site remote control. This class of radars is designed for radar control by extracted , synthetic data only .

The technique employed in this extremely advanced , computerized radar is so far from the traditional radar that raw video presentation is not even considered for operational use.

The confidence and precision of the digital data is an order of magnitude better than the old 'banana' paint . The new radars are available in both L- and S-band, and with both magnetron or klystron transmitters .

Sector Suites The Selenia sector suite, or controller ¡s workstation . is completely computerized. Selenia employs 3 types of displays at its sector suite: DDS-80 : Digital display system with built-in computer and advanced man-machine interface.

This display is particularly well suited for precise presentation of radar data. with 22" screen and very high contrast ratio.

CDS-80: Common display system . also with built-in computer and advanced man-machine interface .

The display is a high definit ion raster scan display, well suited for alphanumeric and graph ics presentations . The display is typical ly used in control towers, or as part as the sector suite for A/ N presentation. procedural situation monitor. as radar display back-up, as technical supervisor monitor, or as a radar simulator display .

Alphanumeric VDU ' s, coup led to the computers either via concentrators. or directly to a processor as a workstation.

Computers For the last decades . it has been Selenia's company policy to produce its own computers . The reason for this is obviously the wish of Selenia to be in full control of all systems installed worldwide . and not under control of a computer manufacturer . Selen ia has now developed the MARA system .

The principal mot ives Which led to the design of the MARA system were: The availab ility of powerful microchips; The growing importance of dist ributed architecture ; The pressing requiremen t for a highly modular computer ; The requirement to reduce app lication software cost by using advanced software factory tools.

The MARA system employs the Intel 86 series. in current produc tion the 80286 16-bit version. The MARA 286 is a multi microcomputer or iented

ATCR-330 S-band radar. Oslo. Norway

9

to a wide range of real time applications. It is based on a multiprocessor (or node) network . The processors within the multiprocessor are connected to each other via a nodal bus.

Complete separation between the funtional structure and physical structure is assured at each level.

The system software configuration is obtained by the SCL (software configuration language), which provides the interface between the high level language and the physical computer.

The MARA computer is used for all high capacity requirements. A special version 286 is used for more local requirements.

Software

Modules

An important consequence of a modular system concept is the extreme modularity of the software packages. Selenia has divided the ATC systems into three different levels, each with an increased degree of complexity. The software modules in

Software

Sector Suites, Mazatlan, Mexico, area control center

these levels have been tested for years in many different systems in more than 30 different countries .

The total system is built over a system skeleton. where the various modules are written as needed.

Module Description System Level

Radar Data Automation Radar data extraction PSR/SSR data combination Geographic radar data filtering Monoradar tracking Multiradar tracking Narrow band data transmission Synthetic data display Video mapping Autonomous stroke display Autonomous rasterscan display Sophisticated man/machine interface Radar conflict analysis Automatic hand-over and sectorization Recording and play-back Technical monitoring ATC Simulation Airspace struct ure simulation Sensor simulat ion Navaids sim ulation Exercise supervision Pseudo-pilot positions Monoe xercise ' Multie xercise Exercise recording and playback Flight Data Automation AFTN/C IDIN interface Automatic data aquisition from AFTN Trajec tory development Flow management Flight strip printing 1st strip

10

System Level

1

2

3

4

X X X X

X X X X

X X X X X X

X X X X X X X X X X

X X X X X X X X X X X X X X X

X X X X X X X X X X X X X X X

X X X

X X X X X X

X

X X X X X X X X

X

X

X X X X X X X X

X X X X

X X X X X X X X

X X X X

1

Flight Data Automation (cont.)

Flight strip printing for all strips Trajectory-flight plan correlation Trajectory-flight plan tracking Automatic generation of messages to other centers Management of meteo data Advanced management of meteo data Management of NOTAMs Generation and management of flow messages to other ACC Integration of several centers and I or FIRs Int eractive database management Global system database management Stripless system with graphic FPL presentation Technical Supervision Radar site remote monitoring Radar site remote control Radar site telediagnostics and setting Radar site access control ATC center configuration control Firealarm a,:id antiintruder control Personnel recognition Alert handling AIS Automation NOTAM automatic handling Tools for NOTAM generation and sending Pre-flight information bulletin handling Aeronautical database handling Remote pilot briefing

2

3

4

X

X X

X X X

X X

X

X X X X X

X

X X X X

X X X

X X X X X

X X X X X X

X X X X X X X

X

X

X

X

X X X

X X X X

THE CONTROLLER/ JUNE 1988

Philips' Breakthrough in Recording Technology Sets New Standards in Communications Logging

The logging of telephone or radio messages is becoming a vital aspect of communications in today's public services. industry and commerce . As greater amounts of urgent or complex information pass between various locations . so the people who must act on that information are relying more and more on the safety of a recorded back-up .. . people like air traffic controllers. currency dealers and ambulance operators . To ensure that logging equipment can continue to meet the increasingly stringent requirements of traditional and newer application areas. Philips have successfully refined an innovative technology for recording audio signals on magnetic tape .

Squeezing 64 Audio Channels onto Half-Inch Tape The new technology is thin film tape -head construction. in which tiny heads are made in a comparable way to an integrated circuit. This revolutionary new technology forms the keystone of Philips' latest generation of communications logging recorders - the CLS 8000 family. which was specifically designed to set new standards in compactness. ease of use. cost of ownership and security of recording. Philips ' advances in thin film t ec hnology made all this possible by allowing the first -time use of halfinch tape cassettes for round-theclock rec ording of analogue audio signal s from up to 64 simultaneous inputs. The CLS 8000 family includes 28 models. offering 12 or 24 hour record ing capability. with capacities between 8 and 64 channels. Every model uses exact ly the same typ e of casse tte . which measures ju st 8 X 11 X 2.5 c m .. . about the size of a paperback novel. The advantages of cassettes over ree l-to- reel tapes have already been proven in hi-fi and video applications. In communications log ging howe ver. the use of cassettes for recording as many as 64 channels over prolonged periods has been prevented mainly by t he lim itation s of conventiona l tape head s. They cannot THE CONTROLLER/ JUNE 1988

supply an adequate signal from very narrow track widths while operating with the low tape speeds needed for 12 or 24 hour continuous recording on short cassette tapes . Philips' solution involved a refinement of thin film heads that were originally devised to allow high capacity recording of digital data (for this reason . thin film record and playback heads are usually referred to as write and read heads).

Philips Proven Technology in Action The CLS 8000 family represents the first successful commercial implementation of thin film heads for analogue recording . There are 28 models in the family. including 36 to 64 track machines (asce nding in groups of 4 tracks). and 16 to 32 track models . All have dual decks as standard. and at the lower end of the range there are 8 and 12 tra ck machines. although these models use conventional ferrite heads . Each of the three groups also has its own reprodu ce r.

CLS 8000 recorder s are characterized by their compact size and neat appearance. Tape transport and head assemblies are hidden to the outside world. ma king CLS 8000 machines safe to use in busy or crowded environments like offices. In addition . foolproof operat ing procedures mean that users unfamili ar with logging recorders can handle day-to-day system management in total co nfidence.

Apart from being easier to handle. cassettes offer numerous other advantages over conventional reel tapes. Firstly. th ey can help cut costs . beca use less tape is required for a given recording duration . Secondly. each cassette has a sliding record / protect sw itch . which means that valuable reco rdings stand less chance of being erased accidenta lly . Thirdl y. archiving of cassette s is more convenient. And fourthly . they can be removed from the machine directly at any point . In playback sessions this saves having to w ind or rewind to the end of the tape before removing it: if a half spooled cassette shou ld be

inserted for recording . CLS 8000 automatically rewinds the tape first.

A programmable time system is a standard feature on all models. allowing sequenced recording and fast searches for recorded information.

There are other valuable features t oo . including voice or contact operated recording . and automatic gain reduction to limit excessively loud signals . A remote control panel is also available . allowing full system control and monitoring from locatio ns up to 100 meters from the recorder.

Philips CLS 8000 fam ily is a step forward for communications recording. both technically and in terms of greater convenience for users . The space saving aspect of t he new machine s is expected to find favor with communications centers that have very high rental costs; for example. the dealing room s of financial institu t ion s and organizations in the world's major cities. Others that will benefit will include emergency servic es. airport s and security organizations . or anywhere that convenient and highly reliab le recording of high density co mmunicat ions traffic is essential.

a

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Philips ' new CLS 8000 system records up to 64 channels .

11

High Blood Pressure Control, Risk, Lifestyle, Weight

Editor's Note: Past medical studies have tended to show a higher than normal incidence of high blood pressure (hypertension) in air traffic controllers. There were unanswered questions as to the possible causes of these findings, as well as a number of valid suggestions for their reasons. The text below is reprinted with the kind permission of the American Heart Association, a non-profit organization dedicated to reducing the risk of high blood pressure and of heart disease of any kind in humans. It is, of course, not specifically directed to air traffic controllers but, if the aforementioned studies were correct, air traffic controllers should take particular notice. The material is copyright and is being provided for educational purposes only. There is no commercial relationship between The Controller and the American Heart Association. hhh Blood pressure- everybody has it. and everybody needs it. In fact. without a certain amount of pressure in your vessels. your blood couldn't circulate through your body. And without circulating blood. your vital organs couldn't get the oxygen and food they need to keep functioning. Clearly. blood pressure is important.

A person's blood pressure doesn't always remain the same. however. It changes constantly. varying from day to day and moment to moment according to your body's needs. For example. your blood pressure will rise wh~n you're exercising or you're excited. and it will drop when you're resting or asleep. Fluctuations are perfectly normal.

ft V

American Heart Association

in turn. branch off from the aorta. the main artery from the heart.)

To understand how arterioles regulate blood pressure. think about how a nozzle regulates the water pressure in a hose. If the nozzle is wide open. it takes relatively little pressure to force the water through the hose. but if the nozzle is partially shut (or you clamp your thumb over the opening of the hose). the water pressure in the hose increases.

The same principle applies in your blood vessels. If for some reason your arterioles are narrowed. it's harder for the blood to pass through them. When that happens. the result is that your blood pressure rises and you~ heart works harder. If the pressure in your arteries increases to 140 / 90 (or more) and stays there. you have high blood pressure.

About 90% of the cases of high blood pressure have no known cause.

This form of high blood pressure is called ¡essential' or 'primary' high blood pressure. That's what this booklet is about. When high blood pressure has a specific cau~e. resulting, for example. from a disease or physical problem, it's called_'secondary' high blood pressure. This booklet doesn't discuss secondary high blood pressure.

levels of blood pressure: an upper one when your heart is beating. and a lower one when your heart is resting.

The higher reading is called the systolic pressure; the lower one. the diastolic pressure.

When a doctor or other health professional takes your blood pressure. both levels are measured and are recorded as numbers. For example. let's say your blood pressure reading is 124 / 80 ( 124 over 80). In this example the systolic reading is 124; the diastolic. 80. The numbers are calculated in millimeters of mercury and would be written as 124/80 mm Hg. These two numbers provide some very important information about the state of your health. The systolic pressure is important because it tells the maximum amount of pressure What's Blood Pressure? exerted on your arteries; the diastolic pressure is important because it tells What Causes High Blood The beating of your heart pumps blood through large blood vessels the minimum pressure on your arter- Pressure? ies. The harder it is for the blood to called arteries that conduct blood Why essential high blood pressure from your heart to other parts of your flow through your blood vessels. the occurs isn't known. Research scienhigher both numbers will be and the body. As your blood is pumped tists are trying to piece together an through your arteries. it pushes greater the strain on your heart. answer to this mystery. however. and If you're wondering whether against the arterial walls. This force they're pursuing some important there's an 'ideal' blood pressure against the walls of the arteries is reading. the answer is. there isn't one. leads. called blood pressure.

For instance. although researchers A healthy person's arteries are Acceptable blood pressure falls within haven't discovered specific causes. a range rather than being a particular muscular and elastic. They stretch or pair of numbers.

For most adults. c1 they have learned of some factors th~t contract when the heart pumps blood blood pressure reading that's less increase the chance that a person will through them; the amount of stretchdevelop high blood pressure. These ing depends on the amount of force than 140/ 90 mm Hg indicates there's no cause for worry. predisposing factors _include her~~i~y. the blood exerts. Each time your heart sex. age. race. obesity and sens1t1v1ty contracts (about 60 to 80 times a to sodium. Related factors that also minute under normal conditions). it seem to have some bearing on high sends a surge of blood into your arter- Whaf's High Blood blood pressure include heavy alcohol ies. and the blood pressure in your Pressure? consumption. the use of oral contraarteries increases. Conversely. when ceptives and a sedentary lifestyle.

Arterioles. smaller vessels that your heart relaxes between beats. your A brief explanation of each of these branch off from the arteries. regulate a blood pressure decreases. From this. person¡ s blood pressure. (The arteries. factors follows. it follows that you really have two 12

THE CONTROLLER/JUNE 1988

Heredity Experts who've studied high blood pressure have found that a tendency toward high blood pressure often seems to run in families. In other words. if your parents or other close blood relatives had high blood pressure. you're more likely to develop it than someone whose close blood relatives had normal blood pressure.

If your family history reveals that close blood relatives have suffered strokes or heart attacks at an early age. or had or have high blood pressure. you and other members of your family should take care to have your blood pressure monitored regularly.

Sex Men are more likely to develop high blood pressure than women. After menopause. however. women's risk of high blood pressure increases.

Age High blood pressure occurs most often in people over the age of 35.

Men seem to develop high blood pressure most often between the ages of 35 and 50. while women are more likely to develop high blood pressure after menopause. In general. the older a person gets. the greater the chance that he or she will develop high blood pressure.

Race Black Americans develop high blood pressure more often than whites. and it tends to be more severe.

pressure. The risk of developing high blood pressure is increased several times when women take oral contraceptives and also smoke cigarettes.

When women who take oral contraceptives are also overweight. have had high blood pressure during pregnancy. have a family history of high blood pressure or have a condition such as mild kidney disease. the risk of high blood pressure also is increased.

Sedentary Lifestyle A sedentary lifestyle tends to contribute to obesity. which is a risk factor for high blood pressure. Regular exercise helps to control weight and relieve anxiety.

Can You Tell When Your Blood Pressure Is High?

No. definitely not. High blood pressure has no symptoms. In fact. many people have high blood pressure for years without knowing it. That's why it's so dangerous.

The only way to find out if you have high blood pressure is to have your blood pressure measured. Yourdoctor or another qualified health professional should check your blood pressure at least once a year.

How Can High Blood Pressure Damage Your Body?

Uncontrolled high blood pressure can damage your body in a number of ways. Mainly. it adds to the workload of your heart and arteries. Because your heart is forced to work harder than normal for a long period oftime. it tends to enlarge. A slightly enlarged heart may function well. but if your heart becomes significantly enlarged, it may have a hard time keeping up with your body's demands.

As you grow older, your arteries Sodium Sensitivity and their smaller branches. the arteriAmericans consume far more oles. will harden and become less sodium than their bodies need. And elastic. This process takes place heavy sodium consumption increases gradually in all people (regardless of blood pressure in some people. which whether they have high blood presscan lead to high blood pressure. As a ure). but having high blood pressure result. many people who are diag- tends to speed up this hardening pronosed as hypertensive are placed on cess.

The possibility that you might have restricted sodium diets. a stroke is also increased if you have Alcohol Consumption high blood pressure. Uncontrolled Studies have shown that heavy. high blood pressure can also damage regular consumption of alcohol can your kidneys-.

Although essential high blood increase blood pressure dramatically. pressure can't be cured. it usually can Oral Contraceptives be controlled. And its effects can be Women who take oral contracep- prevented or reduced if it's treated tives may experience elevated blood and controlled early. and kept under

Obesity Studies have shown that obese individuals (people whose weight is 20% or more above their ideal body weight) are more likely to develop high blood pressure. People who are overweight (less than 20% over their ideal body weight) are more likely to have high-normal to mild high blood pressure.

THE CONTROLLER/JUNE 1988

control. If you have high blood pressure. follow medical advice and take medication if it has been prescribed.

High blood pressure isn't something to take lightly. On the average. individuals with uncontrolled high blood pressure are three times as likely to develop coronary heart disease. six times as likely to develop congestive heart failure. and seven times as likely to have a stroke as individuals with controlled high blood pressure. It's "':'Orth repeating: If you're hypertensive. follow medical advice and take prescribed medication.

What Can Be Done About High Blood Pressure?

Diet Most treatments for high blood pressure rely on some combination of diet. exercise. and medication to bring blood pressure under control. A brief discussion of each alternative follows.

Statistics show that many people who have high blood pressure are also overweight. If you weigh significantly more than your ideal body weight. you'll be advised to cut down on calories and lose weight. Your doctor can prescribe a diet that's right for you.

Other qualified health professionals (registered dietitians. nurses. phys!cian¡ s ~ssistants. etc.) can guide you 1nstarting or following it.

If you're given a diet. follow it closely. including any recommendations about reducing your consumption of alcohol. Alcoholic drinks are high in non-nutritious calories. so if you're trying to lose weight. avoid them.

Often when people lose weight. their blood pressure drops automatically. Being overweight is a general health hazard. so by losing weight you'll not only help your blood pressure. but you'll help yourself stay healthy in other ways. too.

Sometimes reducing sodium consumption can help lower blood pressure. If this might help you. your doctor will recommend a sodium (salt)restricted diet. A reduced-sodium diet will mean you'll have to avoid salty foods. cut down on the amount of salt you use in cooking and at the table. and start reading package labels regularly to learn about the sodium content of prepared foods. Don't be concerned about eating less salt. however; most Americans eat far more salt than they need. and by experimenting with herbs and spices as seasonings you can still enjoy deliciously flavorful meals.

13

The important thing to remember w ith any modified eating plan is that it should be prescribed by your doctor .

Don ' t ma ke major changes in your diet wi t hout f irst getting proper medical advice . And once a diet has been presc ribed fo r you. stick to it .

Exercise and Recreation Having high blood pressur e doe sn't mean you have to become an inva lid . In fact most people whose blood pressure is being controlled continu e the ir usual activities . Don ' t be afraid t o be active ; exercise should def init ely be part of your dai ly program . It can even help you lose weight or m aintain your ideal weight .

Your doctor or other qualif ied health professio nal can suggest the best kind of exerc ise program for you .

Wh atev er exerc ise you enjoy and do reg ularly wi ll prob ably be satisfactory .

2 . If your doctor prescribes blood pressure medications for you . ta ke them as directed. If you don 't feel well after taking the medication, tell your doctor exactly how you feel. This information will help your physician adjust your treatment so you won't have unpleasant side effects .

3 . Follow medical advice regarding diet and exercise . Make a concerted effort to lose weight if it's recommended. and make changes in your general health habits (such as getting more exercise) if you need to.

4 . Remind yourse lf that as long as you and your team of health advisors work together . you can control your blood pressure .

Unfortunately . high blood pressure is a lifelong di sease. and one th at can 't be ' cured .' But don't despair .

Usually it can be controlled . Once you've started a treatment program. you'll find that managing your high blood pressure is easier and less complicated than you thought. And by controlling your high blood pressure. you'll lower your risk of diseases like stroke, heart attack . heart failure and kidney disease.

You can do it! Good luck!

( Reproduced with permission. Š About High Blood Pressure American Heart Association)

M edication For some people . weight loss . sodium redu ct io n and other lifestyle changes wo n't low er high blood pressure as muc h as it needs to be lowered. If t hat's your situation . you ' ll need to t ake med icati on .

Man y m edicat ions are available to reduce high blood pressure. Some get rid of excess fl uid and sodium (salt) . whi le othe rs open up narrowe d blood vessels . Still oth ers prevent blood vesse ls from const rict ing and narrowing.

In most cases of essen ti al high blood pressure. medicines wi ll low er blood pressure. Every perso n reacts differently to medication . howeve r. so if you need medic ine. a t rial period may be necessary before you r doc tor finds the med icine t hat works best fo r you.

1

The Good Old Days - Only Better!'

A special group of air passengers is the market targeted by 'Classic Air' . the aviation nostalgia buff . the DC3 enthusiast .

Classic Air wa s founded in 1985 in Switzerland and operates two DC3s . the acquisition of a third one is planned for the near future .

Each aircraft carries 28 passenger s in comfortable seating arrangement s. contr ibuting to the achievement of Classic Air ' s objective of

offering the experience of flight at alti tudes where the passenger can observe details of the land below or of the surrounding mountains. coupled with exclusive service on board and individual attention to the guest.

In J anuary 1988 Classic Air celebrated its 10 000th passenger on its 651 st flight , quite an achievement for a company which caters to people who get on board an aircraft strictly for the joy of flying .

How Can You Help Yourself?

It takes a team to t reat yo ur hig h blood pressure successf ully. Your doctor or qua lified healt h professio nal can ' t do it alone. and ne it her can yo u .

You've got to work together. But even though it's a team effort. you ea n do more than anyone else to bring yo ur blood press ure under contro l - and keep it there.

You can help yourself by do ing the following: 1. Keep appointments w ith your doctor . Do ing so wil l help everyone c oncerned monitor your blood pres sure program and make whatever ad j ustments are necessary to keep your blood pressure under con t rol .

14

DC3 in the A lps THE CONTROLLER/ JU NE 1988

Modernization of Air Traffic Control in Egypt F. P. Martinoli, Sofreavia-Service

The rapid increase of the civil commercial air traffic due to the spectacular growth of international tourism in Egypt, as well as the obsolescence of the existing equipment made it a priority for the Egyptian Civil Aviation Organization (CAO) to reorganize and modernize the air traffic control service .

Based on a twenty-year plan studied by Sofreavia (French aeronautical consultant company), Egyptian Civil Aviation took the decision to imple ment. in two phases, (objective 1985 and 1992) a complete new air traffic control system, based on the automatic processing of the radar information and flight plan data.

Thomson-CSF was contracted to realize the first phase of the project. completed in 1985.

This phase includes : a 7 ,OOOm 2 building to house the new control centre. in charge of all of the Egyptian airspace; two long range rada_ r stations (LP 23K) installed at Cairo and Asyut and one short range radar station (TA 1OK) located at the airport of Cairo . All stations are equipped with primary and secondary radars; THE CONTROLLER / JUNE 1988

a new control room equipped with four en-route positions and two TMA positions and a new IFR room equipped with three approach positions (two arrivals. one departure); a new computer room for the automatic processing of the radar and flight plan data ; modernization of the communication network (air/ ground and point/ point); a new automatic switching centre ; extension of radionavigation aids facilities ( 12 VOR, 11 DME); an ATC simulator.

The second phase. planned for 1992. will include: extension of UHF /VHF air-ground communication coverage; extension of radar coverage with installation of a long range radar in North-West (Mersa-Matrouh) and South (Aswan) .

Men More Important Than Equipment Very quickly Egyptian Civil Aviation realized that these high technology tools will only allow an increase in airtraffic and improve the flow control while the safety of flights is increased if they are reliable and well used.

Sophisticated tools will be useless without skilled personnel for operation and maintenance . Thus. Egyptian Civil Aviation asked Sofreavia-Service to define the manpower requirement s. to insure the training of the required staff and to provide technical assistance (for operation and maintenance) during the start-up of the new system.

The setting-up of the new equipment required the recon siderat ion of the organization of air traffic control service. and demanded from all personnel of the centre a big effort of adaptation and updating of their knowledge .

Although the construction of the new centre was a huge investme nt, training was not forgotten and Egypt granted a very big effort to thi s purpose .

From 1982 to 1984. about 460 air traffic controllers. engineers and technicians were sent to France . Theoretical and practical courses were performed. using the facilities available in the equipment factor ies, Sofreavia and ENAC (French Civil Aviation Schoo l). on automated radar control and on advanced technolog y equipment .

Change-over The technology gap bet ween the former and the new centre imposed a great change on the way of operat ing for all the personnel. A drastic shifting plan was formed to allow a safe and speedy transfer from the former to t he new center.

Much more imp ortant than the change of building . the crucial and difficult change was to move from a manual strip writing procedu ral control environment to an automatic fligh t plan data processing - radar control enviro nment.

A step-by-step strategy was carried-out, based on the principle that it was mandato ry. for the safety of aircraft. not to change - at the same time - the tools and methods of wor king . So. the following steps were implemen ted: Shadow operation: during this period , the new system wa s working as in 'real' cond ition but oper at ional control of the tra ffic remained the respons ibil ity of the former one; Operationa l start-up of the centre , setting-up of the new devic es; Progressive introduct ion of radar information and survei llance services Slight proced ure modifications . imposed by use of radar. were introduced.

Progressive introduct ion of radar control (from a few hours at the beginning to . fi nally . 24 hours) ; Implementation of new instrument departure and arrival procedure s (SIDs and STARs). and associated navigational aids installed .

15

Organization of the Egyptian ATC system

Training Radar contro l allow s to acce lerate the movement of air traff ic by reducing the separation between aircraft it increases t he respons ibi lity of the contro ller and t he impact of human error on the safety of the flights.

16

The aim of procedural and radar contro l is the same - safety of flight but the methods of work are quite different. So, the courses were estab lished to be more of a conversion or transformation training than an improvement training .

Refresher courses on air traffic control were not forgotten , especially to up-date and reinforce know ledge of phraseology and aircraft performances .

All the operational staff contro l as well as ATC management received THE CONTROLLER/ JUNE 1988

,

1

Cairo Air Navigation Centre - General view

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THE CONTROLLER/ JUNE 198 8

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17

basic training on the overall system. allowing them to understand the accuracy of the data provided by the system and operational limitations imposed by equipment characteristics . Through this means controllers understood and applied more accurately the operat ional procedures imp osed to override technical limitations or failures.

To speed-up the improvement of ATC service with introduction of radar service. an intermediate radar information and surveillance rating was established . Controllers were allowed to continue their training to radar control qualification only after several months of practice on the spot as radar info rmation and surveillance controlle r.

This method has proved efficiencent and has allowed : quick improvement of ATC services ; familiarization of the controllers with the new environment before continuing their tra ining ; progressively introducing pilots to radar service .

As the introdu ction of radar control required modification of the general organizat ion of control rooms (enroute. approach and tower). of coordination proced ures. airspace organization and sector ization . not only radar controller training was necessary. This reorganization called for specific training for aerodrome controllers (clearance delivery position and ground control position). assistants and operators of the flight plan process ing system.

Technical Assistance Theoretical and practica l training in classroom or simulator has not replaced experience acquired on the spot in real operat ion. Assistance of

experienced technical and operational experts was a great help to a speedy and safe start-up of the new centre.

Moreover. in addition to giving advice for the reorganization of air traffic control service. operational experts have been working as radar controller instructors performing training on radar simulators (using the new procedures in the exercises) and in the position in the control room.

The technical assistance was mandatory to ' prime the pump'. and to ensure continuity of quality special attention was paid to train future instructors in order for the Egyptian Civil Aviation to be self-sufficient for its own training needs.

The ambitious training plan set up

by Sofreavia-Service in collaboration with the Egyptian management staff

required the active and pos1t1ve participation of Egyptian expertise side by side with the French experts. That organization allowed easy transfer of training responsibility to the Egyptian counterparts without a single major problem and added much to the sum of achievements.

Well aware of their new assignment. the Egyptian instructors and controllers rapidly assimilated the new environment concept and through sincere dedication set an outstanding record in the provision of Radar Control Service on a 24-hr basis .

The start-up of the new Cairo Air Navigation Centre has not been an easy task . but thanks to the efforts of the whole civil aviation team . Egypt can be proud of this major ach ievement.

ICAO Audio Visual Training For more than 40 years . the International Civil Aviation Organization (\CAO) has made available audio visual training aids aimed at fostering and facilitating the training of flight and ground person _nel. Posters . audioslides and films / videos covering a wide range of subjects such as aviation security. air traffic control. flight operations and meteorology are produced in English. French and Spanish . _ Recent improvements in the reproduction process have made po~s1ble a significant reduction in the price of these training aids . Complete information on the products . prices and ordering procedures can be found 1n the Catalogue of ICAO Audio Visual Training Aids which is offered free of charge. This trilingual (English . French and Spanish) catalogue or additional information can be obtained from : Audio Visual Aids Unit International Civil Aviation Organization 1OOO Sherbrooke Street West Montreal . Quebec H3A 2R2 . Canada

Inside the new Cairo ACC

18

THE CONTROLLER/ JUNE 1988

In today's overcrowded skies, Cossor Condor presents the true picture

Nightmare or reality? The fact is that today's air traffic controller is faced with ever -increasing traffic densities and needs the most sophisticated equipment at his disposal to make the safest, and the most efficient , use of the air space.

This is why the Cossor Condor 9600 is such an advance. It represents the latest generation of the world's leading monopulse secondary surveillance radar and display system.

Accurate bearings, clear tracks coupled with: full integration with primary radars; solid -state reliability; the latest daylight viewable rasterscan displays (in monochrome or colour); large vertical aperture antennas for interference-free coverage; remote monitoring and fault diagnosis for ease of service - these are just some of the features of the Cossor Condor system.

If you would like to be fully in the picture , please contact us at: Cossor Electronics Limited The Pinnacles, Elizabeth Way, Harlow Essex CM19 SBB, United Kingdom Telephone: (0279) 26862 Telex: 81228 FAX: 0279 410 413

Cossor A Raytheon Company

Cossor

Cossor A Raytheon Company

9600 Monopulse SSR System

General This article decribes the Cassar 9600 Monopulse Secondary Surveillance Radar (MSSR) System. which accesses then processes aircraft replies and outputs them as plot data for ATC displays. The extensive processing enables 400 aircraft to be tracked within a range of 256 nautical miles (NM). and updates plots every 5 seconds. This makes the system suitable for en-route control. TMA (Terminal Area) or local aircraft recovery applications.

The Cassar 9600 MSSR design has been enhanced by the experience gained in siting 10 monopulse systems for the United Kingdom CAA. and in siting monopulse systems at many international sites. These include Geneva airport in Switzerland; Xiamen airport in China; Bahrain airport; Dubai airport; Mount Himittos for the Athens FIR in Greece and Brisbane airport in Australia.

Cassar is currently supplying 27 systems to the United Kingdom for siting in the UK and Germany for the Royal Air Force. Royal Navy and other military establishments.

Trials at Boston have been completed prior to the delivery of 4 1 systems to Canada. as part of the radar modernization program (RAMP) being carried out by Raytheon.

The 9600 MSSR is being supplied to 3 sites in Sweden and is being offered as the improved monopulse design which will take ATC into Selective Address to· meet future international operational requirements.

Cessor Background Cassar is one of the longest estabished electronics companies in the United Kingdom. was a major participant in the earliest developments and production of radar systems as far back as 19 3 7. and was the pioneer of secondary surveillance radar for civil air traffic applications in the early 1950s. For approximately 25 years Cassar has been associated with the 1

20

Raytheon Company. and currently continues to supply a wide and varied range of products and services. However. the mainstream of current development and production effort is centered on secondary surveillance radar (SSR). and associated military Identification Friend or Foe (IFF) equipment. and display systems for ATC applications.

Cessor Monopulse SSR The Cassar MSSR uses the signal strength from two separate receiver antenna patterns of known shape to define the direction of radar signals.

This gives significant advantages over traditional SSR approaches to improve azimuth accuracy which. like PSR (Primary Surveillance Radar). have tended to use narrower antenna beams and higher interrogation rates.

MSSR operates at a reduced PRF (Pulse Repetition Frequency). which alleviates over-interrogation and so keeps 'fruit' and capture to a minimum.

SSA is internationally standardized in pulse timing and operating frequencies because it is a cooperative system. The agreed SSA frequencies. close to 1 GHz. demand physically large ground antennas for narrow beamwidths.

The number of replies received from a particular aircraft increases with increasing PRF but decrea~es with increasing antenna rotation speed. For conventional. or sliding window. SSR the PRF is chosen for a set rotation rate. The sliding window method of determining the aircraft bearing as the center of its replies !s unreliable. as the bearing accuracy Is dependent upon the system performance at the antenna beam edges which is a weak signal area most vulnerable to distortion due to multipath effects. In addition. loss of replies due to capture. or extra replies due to fruit. can cause the center of replies to be offset.

An error of O.3 ° rms is frequently reached which represents a lateral

position error of 0.4 NM at 80 NM range and 1 NM at 200 NM range but. more importantly. the plot-to-plot variations are seen as track wander on a display which can frustrate the air traffic controller.

The trends have therefore been to increase the PRF to obtain an adequate number of replies. This has led to aircraft transponders suffering increased probability of being occupied or suppressed by interrogators. which creates gaps in the reply train and leads to a general increase in fruit levels.

The monopulse method. on the other hand. employs a lower PRF for a set rotation. It can assess the bearing of each individual reply in the beamwidth. based on comparison of the strengths of signals received in the antenna main beam (called sum) and a second pattern (called difference) which has a null aligned with the peak of the main beam. This comparison produces an ·off-boresight' value which is applied as a correction to the antenna azimuth at the time of detection. This can be repeated on sub~equent replies. and further processing can use the accumulated data to provide an enhanced assessment of bearing.

The low_numbe_rof replies required from a particular aircraft to provide an accurate bearing assessment helps to keep the level of interference suffered by any other local interrogators to a minimum and permits a high rotation rate while tracking a large number of aircraft in a large area of coverage. In the Cassar system of Monopulse SSR. signal strength -~nd monopulse in'.ormation are used in the code detection process. which leads to a great improvement in the integrity of the extraction of SSA reply_ codes. Frequently. closely spaced aircraft can be identified where other methods have failed.

SSR interrogations and replies via reflected paths occur in various ways: elevational deflection. wide azimuth angle. and narrow azimuth angle.

THE CONTROLLER/JUNE 1988

resulting in a number of time relationships. The Cossor MSSR performs hardware and software processes to identify reflected-path replies .

Amongst the information used are:

e

RSLS Signal; • Reply pulse amplitude; • Reply pulse off-boresight measurement; • Range comparison of replies with similar code; • Adapti ve reflector files; • Track (indcluding reply code) file .

Compatibility with Mode S (Selective Address SSR) Purchasing authorities currently considering the purchase of air traffic control radar systems are normally budgeting for the purchase of a capital investment with a desirable working life of 10 to 15 years. At the same time. international ATC radar system evolution is moving towards selective address SSR known as Mode S. The monopulse method of bearing determination is fundamental to these selective address SSR systems .

Cossor has been closely involved in the UK Mode S program since its inception . The Monopul se 9600 system . which meets the technical requirements of the Canadian and Swedish radar replacement programs. includes many Mode S features as standard.

The System

ried out on each pulse. Each cod e pulse amplitude is checked to confirm that it is part of the reply. As a result of this test. a confidence level is assigned to each pulse of the reply . The plot extractor adjusts the instantaneous azimuth information by the off-boresight angle calculated from the SDR to obtain the aircraft bearing.

Pulses are correlated to form replies. then the range is calculated for each reply. Replies are correlated on successive PRPs to build up code information . At least two replies are required to make a target report . A single reply may be assumed to be fruit after a certain time and is deleted.

With successive rotations. the aircraft information is correlated and a track file is built up . Self-adaptive and permanent reflector files are used by the processing to store the geometry of objects that give rise to reflected replies. The self-adaptive reflector file stores temporary reflectors. such as aircraft on an airport. It analyzes the geometry of real and reflected targets to calculate the bearing. range and orientation of a reflector and enters the data in a temporary memory. The permanent reflector file data is stored on permanent memory during commissioning. by selecting the data in the self-adapt ive file. This assists in the detection and suppression of false targets. Plot data containing range and azimuth data with aircraft identity and flight level information . are formatted to be fed to the display system.

Both the antenna and the antenna drive system are designed for highaccuracy monopulse SSR operation.

The 9600 Monopul se SSR (MSSR) system is primarily ~esigned to access and process SSR information from aircr aft within its coverage range. It is fully capable of being upgraded to Mode S. a function which is a feature of the solid-state transmitter design.

Extensive processing on the data available from the 3 channels of the LVA (Large Vertical Aperture) antenna is carried out by the interrogator a_nd the plot extractor. The design policy has been to ensure that maximum use is made of the incom ing signals. while ensuring high probability of detection and high validation of airc~aft codes.

The interrogator transmits a set of Pl. P2 and P3 pulses on each PRP. with the Pl to P3 spacing dependent on the mode . Pl and P3 are fed on the sum channel and P2 is fed on the control channel. The transponder replies with a series of pulses which are received on the sum control and difference ports of the antenna. These are fed to the receivers in the interrog ator. where analogue to digital quantizat ion of the amplitude Is car- Ras terscan display suite. Stansted radar. UK THE CONTROLLER / JUNE 1988

The turning gear has the necessary mechanical precision with on-shaft azimuth data take-off to give the accurate instantaneous azimuth information required by the plot extractor.

Operator Facilities In dual-channel systems the offline interrogator is normally operated to continually perform self tests. Hot Standby Mode is therefore utilized to increase availability. and to provide a virtual · no-break' changeover on detection of a fau_lt in the on-line interrogator .

Monopulse systems are best operated at an optimized PRF. An external system trigger can be accepted but a PRFstagge r is normally applied to the internal trigger. which helps to prevent capture or problems with out-of-range replies.

The monopulse SSR system can be supplied with a dual site transponder as recommended by ICAO . which is placed at a suitable line-of-sight location between 1 and 10 NM from the radar head . The position of the site transponder as perceived by the plot extractor is compared against a known reference, thus provid ing a reliable system check.

As part of a regular system conf idence check . the antenna pattern measurement process can be initi ated.

This uses the site transponder to generate a 3 60 ° pattern of sum , difference and control ports which ca n be used to check that the site performance has not changed since it was commissioned.

21

Cossor Condor

9600 ATC System

Remoted

System

Status

and Control

Display Specifica ti on

Raster scan di sp lays

MONITORING EXPANS IO N INCLUDING PRI MARY RADAR ANO ST AT ION ALARt,.fS

TMA and En-route Applications: SSR CHANNEL

REMOTE

TERMINAL

STATUS CONTROL,4NO FAULT DIAGNOSIS

$TA TUSICONTROL

SSR

16 or 23 inc h round CRT as standard, w ith P31 / P3 9 phosphor to operate at 1500 lin es and 40Hz refre sh , non-interlac ed

CHANNEL DA TA LOGGING

LOCAL

Tower Applications:

TERM IN A L

ATC CENTRE

RADAR SYSTEM

12 inch diagon al, rectangular CRT as standard . P31 phosphor to operate at 102 4 line s, 60 Hz refresh , noninterl aced Display Processor

Environmental Conditions Operational The antenna is operational in winds of up to 160 km/ hour with up to 10 mm of rad ial ice. over a tempe rature range of - 50 ° C to + 55 ° C. The equipment. except for the antenna , will funct ion in an indoor environment as defined below: Temperature 0 ° C to +40 ° C Change in temperature max. 8 ° C I h Relative humidity Oto 95 % Change in humidity max . 5 %/ h The equipment will not emit radiat ion such as to disturb the environment.

Antenna Wind Load The ma ximum survival wind speed wit h 10 mm of radial ice on the ante nna f itt ed to the turning gear is 240 km / hour. The maximum surviva l wind spee d w ith 40 mm of radial ice (radiatorsful lyiced)is230 km/h. For wi nds exc eeding 160 km/ h. the antenna should not be driven, t o allow it to take up a position of minimum to rque and maximum drag .

Man / Machine Interface The interrogator allows various internal values to be monitored via the control pane l d isp lay . These va lues include power rails, output power, PRF and mode inte rlace program.

Analogue video, c lock fr equen cy, pulse shape, tr iggers and mode indents may be moni to red, w ith stan dard test equ ipment .

Plot extracto r power rai ls, trigger and clocks may be monitored w ith standard test equipment . The front contro l pane l, if enabled, allows particul ar self tests to be inhibit ed or cont inu o usly run . Similarly , synthetic targets can be inh1b1ted or mu lt ip lied.

A radar mainten ance monitor di splay allow s raw video and processed p lots to be inspected together with SS R label s. The range and bearing of selected target s are availab le.

22

Display Systems System Features

•

•

• • • • • • •

• •

Princ ipal app licat ions are TMA, ai rport and loca l area contro l, and ce rtain ATCC syste ms Modular system design using distributed data processors for system plann ing and expansion flexibility SSR / primary rada r plot data processing Code / ca ll sig n corre lation Video map s Display of VHF / UHF direction finding informat ion Geographic referen ce co rrection ONH co rrection System monitoring and maintenance, including diagnostic prog ram s Abil ity to upgr ade to co lor display s ATC ope ration simulation as training option

• Typi cal ly 100 m s response to operator con trol s • Refresh rate independent of proce ssing load • Autonomous operation capabi lity Display Presentation

• • • • • •

• • • • • • • •

•

Raw rada r ( PSR an d SSR sca n converted) Video maps Plot extracted data (PSR and SSR ) Trail dot s Mi xed raw and p lot extracted data Dat a table s (SSR code/ hei g ht filter GMT , ONH , arr ivals and departures list with code/ ca ll sign cor relat io n) Di rect ion finding indi cation Operator fac iliti es through fun ction -select keyboard and ro lli ng ball SSR label se lection Tabu lar data Map selec tion Elect ron ic rang e and bea rer marker (readout on CRT) Contro l hando ver Numeric data ent ry (QNH . GMT , SSR code/ height filter rada r dat a channel selecto r and arr ival/ dep art ure time s) Text data input via alphanumeric keyboa rd

In the .issue:

next

IFATCA'88 Rio de Janeiro

Large vertical apert ure monopulse SSR antenna on Cassar supplied tower and turning gea r, Brisbane . Au stra lia

THE CONTROL LER/ JUNE 1988

Accident Compensation Reprint from an article in Plane Facts' (International Foundation of Airline Passengers Associations), Issue 7, September 7987, written by Professor Peter P.C. Haanappel of the Faculty of Law of McGill University in Montreal, Canada.

(Editor's note : While not of immediate concern to some of our readers . the article nevertheless addresses an area of aviation legislation which. as many such others . is in a process of change and evolution . hhh)

How many passengers actually read the conditions of contract and the various notices which form part of their airline tickets? Probably very few .

And even if they do. the lay passenger is unlikely to understand much of them. since they are couched in typically legal jargon and refer to somewhat outlandish international legal instruments . such as the Warsaw Convention.

Yet all these conditions are of the utmost importance to airline passengers as they determine . in large part. to what extent a carrier is financially liable in the event of accidents. delays. loss of or damage to baggage . etc .

Airlines' Liability Limits On most international and domestic flights. the airline's liability for personal injury or death is limited to certain financial ceilings . These ceilings depend on the passenger's itinerary and the legal instruments applicable to that itinerary (Warsaw Convention of 192 9 . Hague Protocol of 1955 , Montreal Agreement of 1966. or domestic law) . The limits - ranging from US $ 10 OOO-$ 75 OOO - can only be exc eeded if it is proved that the airline is guilty of gross negligence or willful misconduct. In practice. this is very rare and requires lengthy and costly legal proceedings.

Fortunately. many carriers - either voluntarily or due to national government regulations - carry insurance in favour of passengers which exceeds the above limits. In some countries as well - notably in the US and Canada there are no financial limits on the airline¡ s liability for personal injury and death in domestic air transportation .

And airline passengers can. of course. take out their own supplementary privat e insurance.

For many years now. there have been proposals for new international THE CONTROLLER/ JUNE 1988

legal instruments , which would increase a carrier's liability for personal injury or death to a more realistic maximum of around US $120 OOO. regardless of whether or not the carrier is at fault . But for a variety of reasons . these have not yet come into force .

The principle of limited liability for international airlines was originally adopted as long ago as 1929 . through the Warsaw Convention . The objective at that time was to protect a then young and vulnerable industry. But the airline industry today can no longer be considered in its infancy and in need of special protection . Air travel is highly sophisticated and generally. extremely safe. So why should an airline 's liability be limited?

By comparison. aircraft manufacturers are rarely protected in the same way . And this is in fact the reason why plaintiffs . in aircraft accident cases . often sue the manufacturer of the aircraft in addition to. or instead of the airline. so as to get around the problem of financial ceilings on liability .

Limits Often Arbitrary Limits on liability are also often arbitrary . A cover of. say. US $ 7 5 OOO may adequately recompense the victim of an air crash who is 70 years old and retired. But the same limit may be grossly inadequate for a 40-year old victim . earning a decent salary and with a non-working wife and three children of sc hool age to support.

The new proposed legal instruments - known as the Guatemala City and the Montreal Protocol s - have been developed on the basis of the following trade-off : while there is still a financial limit on liability, it is more realistic in terms of today's awards and living standards . And the passenger. his estate or dependants do not depend on the fault of the airline for the purposes of indemnifi cat ion .

Extra Protection Needed It is quest ionab le whether th is trade-off goes far enough . though.

Professor Peter Haanappel

And there are certainly other opt ions .

If a carrier ' s liability is going to continue to be limited . passengers need supplementary protection to make the situation more acceptable . Suc h an additional element could be supplementary national insurance schemes. as envisaged by the new international legal instruments in question but not as yet realised .

Another possibil ity is the development of voluntarily structured settlements where the passenger. his estate or dependants agree periodic. revisable payments from an airline or its insurer . taking into account the changing situation of the victim or his dependants .

A more drastic possibility would be to leave compensation for personal injury and death to applicable national laws . thus abolishing the Warsaw family system. But this choice is not very desirable. since it would make legal proceedings even more complicated and thus more costly .

What ever the options . the present situation is unsatisfactory. It is time that states, airlines and insurance companies comp lete the revision process which began 16 years ago with the drafting of the Guatemala City Protocol. still not in force today .

It Pays to Advertise â&#x20AC;˘ 1n 'The Controller' 23

Introducing:

Piaggio Avanti P180

=-

The most innovative business aircraft ever created'

.,.,,..

-------...._

24

~.

. The 100-year-old Rinaldo Piaggio Company of Genoa, Italy. long ago secured an enviable place in aviation history.

Since 1915 when the company entered the aviation industry, it has designed 49 different aircraft models for airline, military, and civil use . Since 1930, it has developed 16 separate engines.

The company now operates two major factories in Italy, with more than one million square feet of sophisticated facilities for design, testing, and aircraft production .

The new Avanti - hailed as 'the shape of efficiency' - marks the company's most recent innovation . It is a business turboprop of unprecedented performance, efficiency, and comfort.

The speed and efficiency of any aircraft is influenced substantially by the degree of laminar flow it can achieve. That is, how closely the onrushing air adheres to the shape of the aircraft as it sweeps from nose to tail.

Flying at greater speeds than any other business turboprop is no small accomplishment . But it is even more significant that the Avanti achieves that high performance on less fuel .

The reason? Superb aerodynamics, paired with an innovative design that is both strong and lightweight. The Avanti's sleek, low-drag shape has been optimized after a six-year progression of windtunnel tests, in both Italy and the United States. It has also been flutter-tested by Boeing in the Convair Wind Tunnel - an advanced procedure usually reserved for jet airliners .

The most unusual aerodynamic feature is the three-lifting-surface concept, introduced in the Avanti for the first time in corporate aviation.

The first lifting surface is the main wing. with the highest aspect ratio of any business turboprop. It joins the fuselage just above the mid position, avoiding sharp angles that can ' pinch' the airflow.

THE CONTROLLER / JUNE 1988

The extra altitude translates directly to extra fuel efficiency. qne reason why the Avanti can offer a Jetworthy range of 2.400 statute m iles.

From cruise speed to climb rate to altitude to range capability . Avanti has stretched the old boundaries of turboprop performance. A breakthrough accomplished with a rare blend of innovation and tradition.

The innovation is obvious in the futuristic shape. the unique forward wing. and the pusher engine desig_~AII primary contributors to the Avant1 s remarkably efficient aerodynamics.

The tradition is embodied in the Avanti 's Pratt & Whitney PT6A-66 engines . the newest generation of one of aviation¡ s most respected engine families.

'The Avanti is the first turboprop to effectively cross the performance line and challenge jet superiority.'

The second lifting surface is the horizontal tail - positioned above the stresses of the propwash so it can be built lighter in weight. The focal point of this unique design is the third lifting surface . on the nose of the Avant1.

This foreplane is not a ¡canard' control surface. but a true forward wing creating positive lift that allows the main wing to be smaller . Thus reducing weight, drag. and fue l consump tion.

To accomplish such an aerodynamic coup. the Rinaldo P1agg10 company used the most advanced design and construction te~hnology.

Airflow hugs the Ava_nt1s unique profile because the skin Is sleek. smooth. and precisely curved. With no sma ll protrusions to cause lar:11nar sepa ration. Even the wind shield / fuselage joint is flush - free of raised seams that snag the airflow.

The distinctive shape was created with the precision of computer-aided design . The fuselage cross-section graduates constantly from front to back. There are no flat spots on any portion of the Avant i's skin. Every section is a smoot h. compound curve.

Traditionally . a distinct line of demarcation has separated turboprop performance from jet performance.

Jets. with their superior speed a_nd power. held claim to the territories above that line . Turboprops droned along below it.

With a top speed of 460 _mph . th e Avanti is as fast as some business Jets.

Significant ly faster than any other new -technology turboprop. And more than 130 mph faster than the bestknown business turboprop.

THE CONTROLLER/ JUNE 1988

The Avanti also cruises at higher altitudes. All the way up to 41.000 feet - while other turboprops fight wind and weather more than two miles below.

Dimensions Length Wing Span Wing Area Height Baggage Capacity Passenger Compartment

14.17 m l 46.5 ft 13 .84 m / 4 5 .4 ft 15.78m 2 / 169.6 ft 2 3.90m /1 2.8 ft 1.20m 3 / 42ft 3 Width 1.84 m l 6'0" Height 1. 7 5 m / 5'9 "

Weights Equipped Wt. Empty Crew( 1) Operating Wt. Empty Payload With Ma x. Fuel Max . Fuel Ramp Wt. Max. Takeoff Wt .

Max. Landing Wt .

3 ,039 kg / 6 ,700 lb 91 kg/ 200 lb 3 ,130k g/6 ,900Ib 454 kg/ 1,000 lb 1,224 kg / 2,700 lb 4,808 kg/ 10.600 lb 4,76 7k g / 10,510Ib 4,529 kg / 9,985 lb

Performance summary Maximum Speed Mmo Vmo Maximum Altitude Ma x. Cabin Press. Diff Stalling Speed (Landing configuration) Takeoff Distance Over 15.2 m / 50 ft Sea Standard Day 2 Engine Rate of Climb 1 Engine Rate of Climb Range (4 Pass. NBM RES)

740km / hr /4 00KTAS 0.67 M ach 4 81 km / hr/260K IAS 12.497 m / 41 .000 ft 9 .0 psi 15 2 km / hr / 82 knots 762 m l 2 .500ft 1.113 mpm /3.65 0fpm 381 mpm / 1.2 50fpm (at 592 km /h r) 3.335 km (at 320 KTAS) 1.8 00 nm

Landing Distance from 15 .2 m l 50 ft Sea Level Standard Day IL-------------------

759 m/ 2.490ft Preliminary data . pending certification ----------~

25

Vigilance and Boredom

Trends:

The information below is an excerpt from a National Transportation Safety Board [NTSBJ of the USA Report on Runway Incursions. While the report concentrated on unauthorized runway use, the principles addressed are equally applicable to air traffic control operations in other environments . hhh

In many of the incidents investigated by the Safety Board , controller worklo ad was found to be relatively light . It is reasonable to question why controllers might forget an aircraft given light workload and fewer aircraft to remember and control . Such errors can be understood by looking at characteristics of controller tasks . In gener al. controller tasks require a great deal of vigilance. which is the ability to sustain attention over long periods of time while processing aircraft movements that may be intermittent and variable in frequency.

When stimuli. such as aircraft, are variable in frequency, there is less continuous inform ation to attend to , which can result in inat tent iveness .

The characte rist ics of ATC tasks are

such that. regardless of workload levels. attentiveness and vigilance are constantly required . However , given human behavior limitations , when the frequency of events is slow, attentiveness tends to decrease . Corresponding to a loss in attentiveness are potential increases in boredom , fatigue, restlessness, daydreaming, as well as an overall decline in physiological arousal or responsivity . When viewed in this way, incidents related to a controller ' s forgetting during relatively light workload conditions are more understandable : the light workload environment with few aircraft leads to a sense of boredom, complacency, and/ or a loss in vigilance. and forgetting occurs at the expense of a potential aviation accident.

We Canadians have a refreshing approach to I ife o We' re enterprising.

Enthusia stic. Energetic o And we bring thes e attitudes to our airline o We look at every aspect of the business of business travel. From check-in to check-out o And where we can, we do things a different, better way o We' re succeeding too.

We've just won Air Transport World's Passenger Service Award o

Association of European Airlines members recorded a 70.1 % load factor in Jurie 1987. reflecting not only a recovery of lost traffic on June 1986, but also substantial real growth in some regions. the association said from Brussels. January-June figures showed a 13.1 % upswing on total international passenger traffic, with European services up 13.2% and intercontinental services up 13 .9%.

Cargo growth was 6.4% in June, but this was the lowest gain since December 1985.

'Air Transport World ' 101 87

Schiphol Airport, Amsterdam, will expand its annual passenger capacity from the current 16 million to 25 million by 1992.

'Air TransportWorld' 2 188

We believe that airline travel needs a fresh approach. So when you have the option, opt for Air Canada o We think you'll enjoy the breath of fresh air we're bringing to flying.

@ A BREATH OF FRESH AIR 26

AIR CANADA THE CONTROLLER / JUNE 1988

s e t IJ

II

SI S

a d e egal

In late January 1988 the President of IFATCA. Erik F. Sermijn conducted liaison visits to two countries in the Africa West Region. Gabon and Senegal.

In both nations there were exchanges of views and information with high ranking representatives of the civil aviation administrations and the air traffic controllers and their associations.

In Gabon the IFATCA President met with Mr. P. ZO'O-Minto'O, the Chief of Air Navigation Services . The talks provided an opportunity to discuss in detail the role IFATCA plays and how it can be of assistance . It became apparent that the Chief of Air Navigation Services understands very well the uniqueness of the air traffic control profession and fully supports the attempts of the Gabon air traffic controllers to achieve proper recognition of the profession and to join the Federation.

Erik Sermijn had occasion to meet with representatives of several general aviation companies and to participate in a very open di sc ussion on air traffic control problems between pilot s and controllers. In Gabon, a country where 80 % of the surface is covered by tropic al forest. air tran sport is of paramount importance and gen eral aviation is an extrem ely well developed sec tor of civil aviation.

During a meeting with the Secretary General of Civil Av1at1on of Gabon m atter s of mutu al inter est were discu ssed . Sub sequent meetings with Gabonese controller s from th e country ' s various airports deepened the resolve to form a controllers ¡ assoc iation and the support of thi s aim by the admini stration with a view to affiliation with IFATCA. A highlight of the visit t o _Gabon was the meeting with the Ministe r _of Transport and the ensuing open discu ssion on variou s aspects of air traffic contro l. inc ludin g the respons1bil1t1e s of air tr affi c controllers . consequen c e of error by controllers . and w orking c ondi t ions .

A visit to the air traffi c co ntrol and related service s faciliti es at Libreville. t he co untry 's m ajor airport , and a THE CONTROLLER/ JUNE 1988

quacy of equipment for use by controllers and the need to plan and prepare for the introduction of radar equipment and ensuing proc edures.

In the course of a vis it to the M ini stry of Transport the IFATCA President and the APCCS d eleg at ion were received by the Director of the Cab inet on behalf of the Mini st er who w as aw ay from Dakar . Thi s provide d a valuable opportunity to off er t he m inistry officials a detai led brief ing both on activities of the APCCAS and th e Federation .

The visits to Gabon and Senegal offered again th e possib ility. to me et person-to-person with the offi cer s of the controllers ' organizatio ns . t he air traffic contro llers . t he rep resent at ives of government s and admini strations . airlines and general aviation. and contributed to furtherin g m utual understanding and impr ess on all IFATCA' s ever-growing rol e and participation in internat ion al aviat ion.

Short Erik F. Serm,jn

meeting with the Chief of Tower and Approach, rounded off the program .

Libreville handles ap proximately 150 movement s per day , other important airports are Port-Gentil and Franceville. and. as radar is not avail able . all air traffic control is procedural.

After travelling from Gabon to Senegal the IFATCA President had an in-depth briefing from representati ves of the Association Profession elle des Contr o leurs de la Circul ati o n Aerie nne du Senegal (APCCAS) which also provided an opportunity for an up-date on Federation activitie s and programs . A detailed discu ssion on prof essiona l and working condition s identifi ed a number of areas where impro vem ents are indic at ed: the need for a better salary stru cture; t he need for improved tr ainin g and refre sher training ; th e need forfamiliariza t ion flight s; the need for assist ance fr om th e authorities to allow APCCA S t o att end IFATCA Confe rences and Region al Meeting s.

Du ring meeting s w ith M r.

M am adou Ndi aye, Dir ector of Civi l Avi at ion , and Mr . Diogamaye Diop .

Direc t or of Air Navigati on , fran k exch anges took place on t he ident if ied areas of co ncern , o n required ade -

Swetron AB (Swe den) has wo n a contract from Civil Aviati on College Gulf Stat es. Oatar / Doha fo r instal latio n of its tower and approach c ontrol (no n-radar) simula t or system in Oatar. The Civil Av iat ion College Gulf Stat es serves all the Gulf Stat es, nam ely Oatar . Bahrein . Oma n and United Ar ab Emirates .

The new simul ator syste m c om pri ses of th e fo llow ing part s : Com m unicat ion syst em Com puterized int egrat ed comm uni cat ion system fo r int erpho ne . te lephone and rad io t raff ic simulat or.

Time setting syst em Comp ute rized di gita l t ime setting, ind ividua l t ime for eac h exerc ise.

Pilot bac k-up syst em Comp uter ized p ilot back -up system to simu late air t raffi c on a real-t ime basi s .

Ai rport light ing/ w arning-ala rm/ navaid sim ulat io n syst ems.

Com puterized sim ulation system to simu late A irpo rt light ing control - W arni ng-alarm situat io ns - Navaid controls The new tower and approach control syst em will increase the capacity of training air traffic contro l students and make the Gulf States self supporting .

27

Interactions are shown by arrows pointing in both directions. This means that. for instance. in the area of ATC we are faced with the unfortunate situation of operational constraints caused by inadequate ground equipment and uncoordinated government control over national airspace.

These may have a determining influence on future aircraft design.

This perception will lead to some key questions:

Interactions between System Capacity and Aircraft Design Messerschmitt-Bolkow-Blohm GmbH/ MBB Hamburg

Which system element will accept the role of an outrider?

Which subsystem will take decisive steps?

Who will act. who must react?

Editor's note: This paper was prepared by MBB and presented at the International Air Transport's (IATA) 21 st Technical Conference. September 198 7.

The theme of the conference was 'System Demand and System Capacity'; the paper formed part of the discussion in Session Three on Technical Initiatives to Alleviate the Problem. hhh

Summary Looking at the total air transport system and its complex structure some examples of the mutual interrelations between ground and airborne system elements are presented and explained. Contributions of aircraft manufacturers to avoid operational constraints have to be evaluated on the basis of a system approach. Collaboration of all system elements involved (operators. industry. airports. air traffic control. etc.) must be accomplished during early project phases.

The coordinated development of future air traffic scenarios is the base for further system evaluations.

General

Without being exhaustive. some examples of the mutual relationships between aircraft design parameters and system capacity are outlined below.

The contribution of aircraft manufacturers to overcoming the growing airport and airspace congestion and to maintaining a functioning air transport system is generally:

Selected Aircraft Design Parameters

• willingness to communicate with all other system elements; • collaboration in system planning; • consideration of system compatibility as a design parameter; • avoidance of the 'it' s-the-other·sfault' position.

The purpose of Figure 3 is to demonstrate how complicated problem solutions appear if the total air transport system is considered. It does not claim to be complete or incontestable in all details. It is an attempt to assess how far the design of the airborne system element can influence the capacity of the system elements on the ground.

Both the list of design parameters as well as the list of effects on system capacity can be expanded.

Existing Interactions In a simplified form Figure 2 demonstrates that the dimensions of an aircraft. its physical characteristics and its performance clearly have an influence on system capacity.

The word ·system· is used to denote the total Air Transport System (Fig. 1) which has three main characteristics.

It is: •

extensive

• complex • dynamic It is the essence of a system that its elements have numerous internal relationships among themselves and any change within an element will directly or indirectly influence the performance of the total system.

Traditionally the interest of aircraft manufacturers has been entirely focused on the requirements expressed by their (potential) customers.

It has also become evident that these airline views. which are often oriented towards the short term have to be complemented by examination of longer term developments of the other system elements in order to identify operational requirements applicable to greater geographic areas and a large number of potential customers.

28

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Figure 1

Air Transport System THE CONTROLLER/ JUNE 1988

Take Off-, Climb-, Descent Performance The capability to operate from smaller runways and airports is unquestionably a contribution to improving the system capacity.

Theoretically. climb rates of more than 1000 ft/min to altitudes above 35.000 ft would be ideal from an operational standpoint .

However. as mentioned for the undercarriage. it is a question of economy and attitude .

Will aircraft operators be persuaded to invest money in improving system capacity rather than merely to reduce their own costs? And another reservation must be mentioned: The delicate subject of environmental resistance. New and perhaps more powerful aircraft designs have to expect a more noise-sensitive population in the future.

t Aircraft design : . size . airframe and systems . propulsion . performance . payload flexibility

Figure 2

Aircraft Size With a large degree of confidence it can be predicted that bigger aircraft sizes will be the only short term solution to meet growing transport demand in the light of the limited increases possible in aircraft movements (airport congestion).

But where is the size limit at which such a capacity gain can turn into capacity loss? This can happen because the runways. taxiways and aprons (not even talking about passenger handling/ landside installations) are laid out to accommodate aircraft of different size characteristics.

Consequently ground separation standards would have to be raised if large wide-body aircraft became the predominant users of certain airports now mainly served by large numbers of small narrow-bodies.

On the other hand the value of possible change in an aircraft's geometry (fuselage length. wing span) ~a~ to_be me~sured against potential limits m the airport infrastructure.

Undercarriage . The system capacity can be increased by reducing separation betw~en landing aircraft and by re~uc_mg runway occupancy times.

This. m turn. would require the ability o_flanding aircraft to leave the runway via the nearest high-speed exit available. with consequent influence on undercarriage design.

It is by no means certain that airc~aft oper~tors would be willing to pay higher prices for aircraft able to maneuver at speed on the ground · only to please tower controllers·.

Noise Reduction Even if this parameter is mainly a request to the engine manufacturers. it must be mentioned here.

If the aerospace industry could succeed in producing a new generation of 'silent' aircraft. then noise emissions must reach a level low enough to enable aircraft operation to be acceptable 24 hours a day worldwide. This of course would bring us an enormous step forward in mobilizing unexploited capacity reserves.

It is understood that any such action as lifting curfews is a highly political issue but. as was said earlier. politics are also part of the system and therefore cannot be excluded from these system considerations.

Figure 3

Wing Design An enlarged range of acceptable horizontal speeds would be helpful in making proposed reductions of longitudinal separation more acceptable from the flight safety point of view. The ability to cruise at higher altitudes would relieve airspace congestion within the preferred cruise level band of today's aircraft designs.

Great circle navigation over the continents in most cases would be feasible if cruising altitudes above 40.000 ft can be reached.

The probability of having to operate on non-optimum flight profiles due to congestion is growing. therefore the operational flexibility of new aircraft designs to adapt to flying conditions which are definitely not ideal will become an important factor in competion comparison.

THE CONTROLLER/JUNE 1988

I

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29

Conclusions The subject of this paper was to out lin e some of the interactions betw een system capacit y and aircraft design and t o see how aircraft manufactu rers ca n con tr ibute to easing operation al constraints within the system .

The foll owi ng steps seem to be import ant to overcome foreseeable difficu lties wi th in the aviation world .

The individual elements of the air trans port system (even if they are extensiv e. comple x and dynami c in themse lves) must be aware that they are ·only ' subsystem s of a greate r tot al system .

It sho uld become the common aim of all members of t he aviati on industry: • to develop agreed met hods of syst em evaluat ion and system desig n; • to develop cost / benefit conside rations w hic h encomp ass the overall system ; • to co mple te system elem ent planning by system plan ning .

The coor din ated modelling of future air t raffi ce scenari os is the base for any system evaluation by simulat ion. etc .

Coord ination and infor mation mu st be accomplis hed du ring early project phases .

In comin g issues of The Contr olle r'

Frankfurt Airpor t Traffic Statistics Soar

With 23 ,305 .603 passengers , 950,700 tonnes of air cargo, 136 ,620 tonnes of air mail and 269,313 aircraft movements , Frankfurt A irport has achieved its best results to date . 1987 once again saw increases in every area of traffic , this time running into double digits: 13 . 7 percent more passengers 10 . 6 percent more air cargo 12 .3 percent more air mail 7. 9 percent more aircraft mov ements These results have not only served to further consolidate the position of the Rhine-Main airport in the field of international aviation . but have also pushed it to the limits of its capacities .

An expansion of the Frankfurt Airport can no longer be delayed . The number of passengers increased at a rate unparalleled in the last ten years. On the North Atlantic routes , increases of over 20 percent were recorded in some month s. In intercontinental traffic. above -average growth rate s were achieved on the routes to the USA . South America. Africa and the Far East .

The increa sing number of take-offs and landings- almost 8 percent more

than in the previous year - has attained a rate of growth unknown since the 60s . In the second half of 1987 . increases ran to 10 percent.

Scheduled flights account for the lion's share of this increase ( + 8 .8 percent) , whereby the increase in foreign air traffic is double that of the increase in domestic air traffic . At 11. 7 percent . the increase in charter flights is the highest .

The new Frankfurt c ontrol tower (OM 40 million) is planned to become operational in summer 1988 . From a height of almost 70 meters and using a new airport movement surveillance radar air traffic controllers will be able to direct and control movements and activity on all runways and ta xiways.

On 21 May 19 2 7 Charles Lindbergh

became the first person to fly solo in an airplane from the North American to the European continental mainland .

6

Low Cost. High Perfor mance ATC Simu lat ion Aerodrome Cont rol Simu lator Voice Driven ATC Sim ulat or Advanced Automated A ir Traffic Cont rol (A 3TC) Making Friends with Fear

30

THE CONTROLLER/ JUNE 1988

Editor 's note: The HOTOL concept is an intriguing on e. While its applic ation, so far, is not the commercial transport of passengers or goods, rather the launching , servicing and recovery of satellites , the craft 's performance charac teristic s are close to tho se of advanced convention al aircraft . Of particular intere st, and impact , to air traffic controllers is the fact that HOTOL would operate to and from existing airport facilitie s. The following material was provided by Briti sh Aerospace Pie. hhh

Proof-of-co nce pt work on British Aero space' s horizontal take-off and landing. single-stag e-to-orbit aerospac eplan e continues to indicate that HOTOL is an entirely fea sibl e concept for th e world ' s fir st fully reusable and highly economic satellite launcher .

Designed to pla ce a 7-8 tonne payload in a 300 km orbit from an easterl y equat orial laun c h, it is 52 m long , 20 m in wing span and has a gros s take-off w eight of about 240 tonne s. Landing w eight is less th an 50 tonn es. Similar in size and w eight to Concorde it has a payloa d bay di ameter of 4 . 6 m to provide co mpatibilit y and inter c hangeabilit y of payloads with the Shuttle Orbit er. At ta ke-off it is eight tim es lig hter th an the Orbi ter assembl y but has doubl e th e payload / t ake-off mass frac ti o n, i.e. 3 % as opp osed to 1.5 %.

The latter figur e is typica l for toda y's co nvent io nal and excee din gly expensive launch ers.

The quantum impro vem ent in perform ance has been achi eved prim arily A rti st 's conc ep tion of Britis h A erospace HOTOL

by the use of a radically new hybrid rocket engine - the Rolls-Royce RB 545 - which breathes air while in the atmo sphere and uses on-board oxygen in the vacuum of space . This halves t he amount of den se liquid oxygen required to be carried on ta keoff . Performance is further enhan ced because wing s allow horizontal takeoff with a much lower level of thru st, and therefore engine w eight than on a vertical take-off vehicl e. HOTOL 's thru st/weight ratio at t ake-off is less than 0 .6 compared with Shuttle 's 1.6 and it get s airborne with the ease and smoothness of a jet fighter , ob viatin g stre ss on the payload .

By elimin ating th e need for launc h t ow ers and st ac king proce dures, hor izontal oper ation saves substa nti ally on laun c h preparati o n cost s. A philo sophy of ·one sat ellit e one laun c h' reduce s payload integ rat ion expense and the unm anned mod e of op erati o n in thi s prim ary role further red uce s cos t s by dispensing w it h

heavy and expensi ve life su ppo rt systems and reducing grou nd control personnel to about 250 comp ared with the several thou sands needed for Shuttle operations . The use of a separate trolle y for take-off means that onl y a light-dut y int eg ral under carriage is needed for lan di ng . The resultant local ma ss savi ng leads to a 33 % decrea se in overall vehic le mass , and gen erate s furthe r sub st ant ial cost savings . Finall y, t he fact t hat HOTOL operate s from a norma l runway, that it is totall y reusable , and th at no part s are jetti soned in fl igh t brin gs the ambi t iou s ta rget of an 80 % reduction in launch co sts w ithi n reach. O nly economie s of thi s order, c ou p led w it h the inheren t fle xibil ity and hig h perform ance of HOTO L, wi ll permit the true co mmer c ial deve lopment of Space .

T he Des ign The w hol e ve hic le Is base d o n a nume rical opt1m1zation betw een ma ss, shape and drag parame t ers .

The con figurat ion is dom inat ed by th e large liqui d hydro gen (LH2 ) f uel t ank, whi c h consti tu t es an integ ral part of the load carrying struc tu re. A n ·aeroshell' is used t o avo id LH2 boil off (at 20 ° K. - 253 ° C) and to with st and re-entry heat ing. The aerosh ell co nsist s of met al panels backed by high -temperatu re insulation and sup ported by t he ta nk struct ure . Conventional nickel and ti t anium alloys could be used fo r t he therm al protection pa nels, but advanc ed mat erials (metal mat rix, carbon-carbon) are being st ud ied for t hei r perfo rman ce advantage s . The liquid oxygen (LOX) tank is 1/st he volume of t he LH2 tank but its content s ac co unt fo r over 50% of t ake-off m ass. Of t he 240 tonnes t otal . approxim at ely 55 % is LOX, 25 % LH2 , 10% airframe, 5% engine s and 2 % systems , leaving 3% as usefu l pay load. The pay load bay m easures 7 .5 m by 4.6 m and is capab le of acc ommo dating very large satel lites, e.g . the Olympus class.

Wor k over t he past 12 months has led t o several changes from the orig ina l des ign: • • • •

• •

THE CONTROLLER/ J UN E 19 88

M odifications to fuselage shape Deletion of the canard foreplanes.

M odifi ed air intake for better engine performance.

Deletion of rear fins (insufficient moment arm relative to centre of gravity).

Substitution of an active. all-mov ing forward fi-n.

Change to an even number of engines (installational con venience) .

31

The major engineering studies currently in hand are : • Propuls ion integration .

• Structures and materials .

• Aerodynam ics .

• Thermal design .

• Command and control.

• Sub-system design.

groundroll 1500 m .

the on-board LOX. Thereafter acceleration continues t o 90 km and a velocity of 7 . 9 km per second where , with an elliptical orbit established, the main engine is cut off and the vehicle coasts to operating altitude, typically 300 km . At this point the orbital manoeuvring engines initiate a circularization burn to establish the desired low earth orbit .

on

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Development Programme

Following the Proof -of-Concept Study there will be sequential project definition and initial development phases over a period of about four Operations years with Enabling Technology ProRe-entry grammes running in parallel. These Operations Base Mission duration can range from programmes will investigate propulHOTOL will operate from a stan12 to 100 hours with 24 hours fairly sion ; structures , materials and manuda rd airfi eld w ith facilities for transport facturing techniques ; aerodynamics typical. Re-entry into the atmosphere airc raft flyi ng-in the prepared pay- is initiated by a de-orbit manoeuvre . (notably hypersonics); advanced subloads; fuel and pyrotechn ics loading The reaction control thrusters ( RCS) systems; command and control ; and bays and a maintenance and loading unmanned flight operations.

Sucturn HOTOL tail first, the OMS then hangar. The operational, technical cessful completion should allow entry fires to reduce forward speed and and log ist ics organization w ill be finally the RCS is used to set-up the with confidence into a development geared to ach ieving a very rapid turncorrect re-entry attitude . For the re- phase beyond 1991, leading to flight round fr om landing to take-off. as little entry phase a high angle of attack is trials in the final two years of the cenas 4 8 hours if necessary . maintained to maximize lift co- tury and operational service at the turn efficient . This enables re-entry to be of the century.

Mi ssions The costs of the development proachieved at high altitude to minimize HOTOL missions can include sat- peak velocity and aerodynamic heat- gramme are currently estimated at a ell ite launch and recovery; servicing of ing . Once peak heating has been round figure of £ 5 billion. The programme is expected to involve experimann ed spa ce stations and un- passed the vehicle is slowly pitched mann ed platfo rms ; microgra vity and down to lower incidence to maximize enced personnel and other resources lift-to-drag ratio and hence cross or of the member nations of ESA to scientifi c experiments ; and military ensure a timely and successful outdown-range performance. In general. op eratio ns . come to the overall programme for a re-entry temperatures exceeding 1200 ° K will occur only under the European Spaceplane .

Ta ke-o ff and Climb When the concept has been nosecone , the leading edges and the Take-off at 280 knots is from a trol'proved ' in the unmanned role, a lips and centre body of the intake . ley and a conventional runway of dedicated manned ver sion will be approximatel y 3. 500 m . Rotation is These ' hot spot s' are in the order of introduced to support the European 1750 ° K. init iated by mea ns of a mechanical man-in-space programme and , subpusher on the t roll ey and then aerodysequently , to undertake manned Approach and Landing namic control s t ake ove r. Provision is missions as required on a world-wide After re-entry the vehicle ' s posmade to abo rt safely du ring the 1800 basis . m tak e-off run o r du ring the climb . In ition , speed and altitude are available from the global tracking network and the lat ter case it is possi ble to divert Conclusion from the Navstar global positioning back to base . to an alternate airfield system . For the final phase of the down range . or to orbit .

HOTOL has the potential not only unpowered glide recovery the upper to reduce launch costs dramatically After take -off the vehicle will po rt io n of the flightpath is lengthened acce lerate to betwe en 500 and 600 and relax launch schedule conknots and t hen c lim b at con stant air- or shortened to cater for tail or head- straints : it will also make in-orbit wind s and an 18 ° glideslope is main- servicing and retrieval of spacecraft speed d uring the airbr eathin g ph ase to Mach 5 at 2 6 km (8 5 .000 ') when th e tained by deploying and retracting the possible . The ease and smoothness of air intake c loses. The engine the n air brake . Descent is at 2 .5 ° to 3 ° , launch could change the design philis at 160 knots . and osophy for future communications co nvert s to pure rocke t power , using touchdown satellites . Perhap s mo st important of all, HOTOL is the key to Europe ' s attainment of total autonomy in Re- Entry Heating Space .

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THE CONTROLLER/ J UNE 1988

Corporate Members of IFATCA AEG Aktiengesellschaft, Ulm, FRG Ansafone Electronic s.p.a., Pomezia, Italy Cardion Electronics, Woodbury, USA CAE Electronics Ltd., Saint-Laurent, Canada Cecsa Systemas Electronicos SA, Madrid, Spain CISET S.p.A., Rome, Italy CON RAC Communications Software GmbH, Rodermark-Waldacker, FRG Cossor Electronics Ltd., Harlow, UK Dictaphone Corporation, Rye, USA Eaton Corporation, AIL Division, Farmingdale, USA Engineering and Economics Research Technologies, Ottawa, Canada Ericsson Radio Systems AB, Stockholm, Sweden Ferranti Computer Systems Ltd., Cwmbran, UK Hollandse Signaalapparaten B. V ., Hengelo, Netherlands EB TeleCom, Nesbru, Norway ISS Videotex A/ S, Charlottenlund, Denmark Jeppesen & Co. GmbH, Frankfurt, FRG Jerry Thompson & Associates Inc., Kensington, USA Marconi Radar Systems Ltd., Chelmsford, UK McDonnell Douglas Electronics, St. Charles, USA Mitre Corporation, Mclean, USA PhilipsTelecommunicatieen Data Systemen Nederland B.V., Hilversum, Netherlands Plessey Displays Ltd., Weybridge, UK Racal Avionics Ltd., New Malden, UK Raytheon Canada Ltd., Waterloo, Canada Schmid Telecommunication, Zurich, Switzerland SCICON Ltd., London, UK Selenia lndustrie Elettroniche, Rome, Italy SEL-Standard Elektrik Lorenz, Stuttgart, FRG Societe d'Etude et d'Entreprises electriques, lssy-les-Moulineaux,

France

Sofreavia, Paris, France Software Sciences Ltd., Farnborough, UK Thomson-CSF, Meudon, France Westinghouse Electric Corp., Baltimore, USA The International Federation of Air Traffic Controllers' Associations would like to invite all corporations, organizations, and institutions interested in and concerned with the maintenance and promotion of safety in air traffic to join their organization as Corporate Members.

Corporate 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.