IA thii laeus:

Sprinttlme in E

Notes en the •El•liaJ•llllll of Dual hnwa.rs

VO L UME 3 N 0 . 3

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Increasing air traffic

necessitate quicker and more accurate detection of

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by employing digital computers to collate and process

flight data and to display the traffic situation at any

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powered traffic.

The system has been ordered by The Netherlands Govern­ment and the first phase is in operational use.

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EVOLUTI ON OF A RADAR Ear ly in 1962. D ec ca c om pleted a s u rvey wh ich showed th em ex ­actly w hat us ers w an ted fo r both A TC and T a c t i ca l T er m i nal us ag e. It also sh owe d that no s in g le radar exis ted capab le of s at i sf y ing the s e nee d s . Th e s pec ificatio n for such a rada r w as dra w n up , and ten months later th e comp lete AR1 system ha d bee n des ig ne d, buil t and evalu ated. It sho wed its elf to be a rad ar of no mea n performanc e. WHAT T H EY WANTED D ec c a found tha t use rs wanted comp lete co ve rage o f app roa ch, land in g , take-off an d hold ing areas , w ith a s ing le rad ar. A radar m oreo ve r, tha t wo u ld be acc ura te en ou g h for contro lli ng fin a l ap ­proa c h. AR 1 g ive s the m just thi s. A t a rece nt demonstrat io n, ob ­servers sa w an airc raft talked in

from 30 mi les away. Control beg an at 5,000 feet- although the radar is capa bl e of operating at up to 45 ,000 feet. Th e aircraft remain ed visi bl e ri g ht dow n to 200 feet , at w h ich t ime it was 600 yards fro m th e radar head . Th e exc ell ent low alti tud e per­fo rmanc e, w hich ext ends to 50 m il es , is o bta ined w ith a parti c­ularl y g ood Mo ving T arget Ind i­ca t io n system. By us ing doub le canc ell at io n, th e sy stem- w hi c h is tra ns istori sed - g ive s sub­clutter vis ib i l ity of th e ord er of 21d B. INSTALLATION NO PROBLEM In t he des ign of th e AR1 great attention ha s bee n paid to easy instal lat ion . Firstl y, th e equ ip­men t ca n be arra nged in any of fo ur c o nfi gurat ions , us ing stan­da rd ca bl e and w aveg u ide runs;

VERSATILE ARl

sec o ndl y, it is unusu all y compact. Th ese tw o fa ctor s minim ise in­stallat ion tim e, make for easy t ransportat ion, and frequ ently avo id co stl y a lterat ion to ex ist ing buildings . CONTINUOUS RELIABILITY Wh ereve r radar mean s safety ­as for exa mpl e in bl ind ap proach -the AR1 shows two major ad ­vantag es . Fi rstly , although us ing th e ' S ' band and obtaining th e ad vantages of ea sy s iting and small aer ia l arrays , th e AR1 does not suffer from weath er clutter. Pol ar isa t ion can be var ied by th e operator from lin ear at 45 to true c ircular , enabling h im to choos e th e best c ond ition for prevail ing c ond it ions . Sec ondl y, a pair of transmitters can be coupl ed to th e aerial, thu s ensur in g contin ­uous service, eve n if on e of th e

pair fail s. I n m on th s o f indepe n­dent test ing th e AR1 has sho w n its elf to be th e ans we r to th e prob lem of pro viding rel iabl e, c omprehensi ve rada r c overag e at a reason abl e pri ce - for th e fi rst tim e.

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IFATCA JOURNAL OF AIR TRAFFIC CONTROL

THE CONTROLLER Frankfurt am Main, July 1964

Publisher: International Federation of Air Traffic Can­t.-allers' A5'aciatians, Cologne-Wahn Airport, Germany.

Officers of IFATCA: L. N. Tekstra, President ; G. W . Monk, Executive Secretary; Maurice Cerf, First Vice President; Rager Sadet, Second Vice President; Hans W. Thau, Hon. Secretary; Henning Throne, Treasurer; Wa lter Endlich, Editor.

Editor: Walter H. Endlich, 3, rue Roosendael, Bruxelles-Forest, Belg ique Telephone: 456248

Production and Advertising Sales Office: W.Kramer&Co., 6 Frankfu.-t om Main NO 14, Barnheimer Landwehr 570, Phone 44325, Postscheckkonto Frankfurt am Ma in 11727. Rate Ca rd Nr. 2.

Printed by : W .Kromer&Ca., 6 Frankfurt am Ma in NO 14, Barnheimer Landwehr 57a.

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

CONTENTS

The Control Load and Sector Design Bar Atid Arod

Volume 3 · No. 3

7

Contributors are express ing their persona l points of view and op in ions, which must not necessar il y coincide with those al the Internationa l Federat ion al A i r Traff ic Contro llers' Assoc iations (IFATCA) .

Bo Lundberg received Monsanto Safety Award 14

IFATCA does not assume responsibil i ty for statements made and op inions expressed, it does only accept re ­sponsibil i ty for publish ing these contr ibutions .

Contribut ions ore we lcome as o re comments and criti­

ci sm . Na payment can be made fa r manuscripts submitted for pubi icatian in "The Controller". The Editor reserves the. r ight lo ;nake a ny editorial changes i n manuscripts,

wh ich he bel ieves w i l l improve the mater ial without a l tering the in~e nd ed meani ng .

Written perm ission by the Ed i tor is necessary IN re­p r inting any part of this Journal.

Advertisers in this Issue: The Decca Navigator Com­pa ny Limited (25); Decca Rada r Lim ited (4); Cassar Elec· I ronies Limited (6) ; Ma rconi Company Limited (1 , 2); N . V. rlollandse Signoo lapporaten (3) ; SELENIA lndu­str ie Ele tt ron iche Associate S.p .A . (Back Cover); Tele· fun ken AG (Ins ide Cove r).

Picture Credit: ATCA Journal (7 8 11 ). Brit ish Features (18) ; W Endl ich (16) ; J. Gertz ' (1 ,5) ; Standard Elekt ri k Lorenz (17 , 20) ; Tirey K. Vicke rs (22 , 23 , 24 )

Springtime in Europe

Tirey K. Vickers

USA ATCA's Ninth Convention

ICAO reports on Air Transportation in 1963

Pioneer Award for Dr.-lng. E. Kramar

Big Picture, Little Picture

Notes on the Employment of Dual Runways

Tirey K. Vickers

Restriction of VFR-Flights on Dutch Airways

5th Convention of UK Guild of ATCOs

IFATCA Addresses

Welcome to IFATCA

15

18

19

20

20

2i

26

26

27

28

COSS OR- BRIGHT DISPLAY Conventional cathode ray tube displays are capable of providing

excellent readout facilities of radar data given the correct environ ­

ment, i.e. low ambient lighting. This environment is far from ideal

for an Air Traffic Controller who is required to read other data and is not necessarily a nocturnal animal.

An ideal solution is to have a display capable of being viewed in

high ambient lighting , daylight or artificial. It must be capable of

displaying radar tracks and other information which is not required

to leave a trail when moved. Also it must be possible to cancel the

picture completely when changing the range displayed, or off

centring. The Cossor Raytheon Bright Display System provides

all these facilities and has been adopted by the F.A.A. in the United States for civil and military air traffic control.

Further information on request to:-

COSSOR ELECTRONICS LIMITED RADAR DIVISION (a subs id iary of A. C. Cossor and Raytheon Co. U.S.A.)

THE PINNAC LES, HARLOW, ESSEX. Telephone HARLOW 26862

The Control Load and Sector Design*

by Bar Atid Arad

B. A. Arad , recently chief of the Operations Division of Israel's Departm e nt of Civil Aviation, is currently with th e Federal Aviation Ag ency System Desi gn Te am on an exchange basi s. A rated pilot as well as a creative mathematician , he has deve lope d a general mathe­matical model that re lates control load, control capacity and optimal

sector desi gn in our air traffic system . No ivory tower theoretician, Bill has assured that his work reflects operational reality by extensive field surveys. He has spent many hours in discus sion of control problems with facility personn el, and in direct obs ervation of control techniques

at sector positions. This Project provides measures of load use ful in sector analysis and

design. The new methods de ve loped open new fi el ds for operational analysis and research in th e field of air traffic control.

Introduction

J. E. Grambart, P-9183 Project Team Member

Th e st ructure of the A ir Traffic Control Subsystem in the enroute environmen t is subdivided into we ll defined jurisdictional units for the exercise of control. Th ese units, commonly known as "contro l sectors", subdivide the entire navigab le airspace in th e enroute env ironm ent. Th e ma­gnitude, shape and orientation of th ese sectors vary con­

siderably. The only planning criteria in existence today

are primarily directed toward manning and do not pro­vide enough guidance for the proper a nd efficie nt design

of the sector. At present there are about 400 enroute control sectors

in the continental U . S. Consequently, any improvemen t in sector des ign wi ll yield appreciable benefits to the system, since more than 50 percent of the annual recurring sys tem

cost is directly proportional to the number of the operat­ing sectio ns. Moreover, total reduction in th e number of sectors will reduce the total amount of sector associa ted eq ui pment on a nationwide basis, save contro l Air-Ground­

Air frequencies, yie ld better frequency management and

reduce cockpit load. Th e respons ibility to provide a given level of serv ice

and the traffic activity in the airspace generates a require ­ment for a contro l effort . This required effort is conse­quently a basic measure of traffic activity or, converse ly, the total traffic activity is a measure of the control effort i·equired. Thi s approach needs further· clarification, the tota l contro l effoi-t can be measured in two p laces:

Reprinted from Journal of ATC by kind pern1issio11 of th e Editor

(1) at the control posi tion , by measu ri ng th e actual work performed, or

(2) in the airspace, by measur·ing the total traffic pheno­mena.

In case (1), the results do not necessarily indicate the relationship between the traffic, the airspace, the rules and the effort of the contro l position. On the other hand, ,-ase (2) exc ludes all effo rt wh ich does not directly affect

the control of traffic. Th e seco nd method is preferred, i.e. , measurement of

the tra ffic variab les a nd definit ion of the effort required by the control position as proportional to the to tal traffic activity . This method was selected becouse the t raffic and the airspace param eters are, by nature, more tangible and measurab le quan tities. Any direct mea sures of the hum an effort both at the behaviora l and the physiological leve ls

cou ld, at best, be used for cross va l idation of some basic a ss umptions.

Th e control effort required has been defined as direct­ly proportional to the total traffic activity. The measure­

ment of this effort must be:

(l) sensitive to all the parameters of ai rspace, traffic and

rule s of operat ion , and

(2) consistent throughout th e navigable airspace.

The effort requir·ed is not meas ured at the control posi­tion and, therefore, is independent of the human control. ler, the contro l equipment, or any combination of man­machine. These, however, ore of a grnat significance when the capacity of the sector is considered. It shou ld be r· ea­lized that for any given leve l of service and sa fety , the ratio between the total traffic activity and the internal capacity of th e system w ill determin e th e " leve l of d iscom ­fort" to th e user. In other words, when the toted effort

requ ired by the contrn l position exceeds the capacity , and the required leve l of safety and service are main tained , the system will generate " discomfort " to the user (i.e. ,

de lays , change of or·iginal intent, etc. ). On the other han d, by adjusting the copacity ond the

effort required , o given level of efficiency con be main ­tained. Moreover·, an y potential increase of capacity by implementing new and better equ ipmen t co n be balanced

7

by delineating sector boundaries to fully utilize this latent capacity.

In the following paragraphs we will attempt to des­cribe how control loads con be measured and how a method of sector design con be developed.

1. Basic Concepts of Load

Safety is a binary concept; on operation is either safe or unsafe. The flow of air traffic is considered to be safe if the rules pertaining to minimum separation criteria are adhered to. The rules do not suggest that safety is a con­tinuous concept but rather that it is a binary function where any instant in the present, and any other instant in the future ore considered safe or unsafe with respect to the relative position of the controlled aircraft. The con­cept "safe" and "unsafe" and the dividing line between the two is defined by the regulations; it is left to the con­troller to decide whether or not the flow of traffic con­forms to the regulations. When it does conform the flow of traffic is deemed safe, but where a situation develops, or may develop which infringes on the regulations, the flow of traffic is considered unsafe.

Let us assume a situation where the flow of traffic is completely free of any intervention by control activity. It is very easy to show that, for many reasons, there is a natural tendency for this freely flowing traffic to converge. That is, in a free flow environment on aircraft will even­tually poss from what we consider to be a safe situation to an unsafe one.

In order to circumvent the natural tendency of uncon­trolled traffic in a free flow traffic environment to develop on unsafe situation we provide a control system. The main function of this system is to provide a specified separation service; that is, to separate the aircraft in such a way that the whole flow of traffic will be safely maintained in accordance with the rules and regulations. In other words, we can define the chief function of the control system as the provision of continuous minimum separation between aircraft and the maintenance of a safe traffic flow. How­ever, th is activity imposes a load on the control system. This load does not, in any way, relate to the way we select to control traffic but only to the traffic activity and the nature I tendency of aircraft to converge and violate our concepts of safety. We will coll this load imposed on the control position the Al RS PACE LOAD, because it is the kind of load which is created by the activity of the traffic within the airspace and is a reflection of what would have happened to the traffic if no control activity had taken place. This Airspace Load will be designated as L2 •

But, in order to separate aircraft one from another and maintain a continuous safe flow of traffic, we have to do many other tasks at the control position. We hove to accept aircraft and to hand them off to other sectors, or to terminal areas. We hove to communicate with the aircraft, to write and update flight strips, organize the strips on the flight progrnss board, accept position reports, coordinate with adjacent sectors, etc. The load imposed on the control position by these activities does not depend on the natural tendency of the aircraft to converge. Be­cause we hove elected to handle each and every control­led aircraft, this load will depend on the number of air­uoft under control. Every aircraft passing through the system requires a certain amount of routine handling which is quite independent of aircraft interaction. The load

8

imposed by this routine handling will be called the ROUTINE LOAD, and will be designated as L,.

Over and above th is we should consider another load component which is imposed on the control position and has nothing to do with the activity in the airspace or the number of aircraft that need handling. This load, which we will coll the BACKGROUND LOAD, and designated by L0 , is the load which is generated by the very fact that each controller has to come to work and has to man his position whether there is traffic or not. The most impor­tant characteristic of this load is that it is entirely inde­pendent of both the traffic activity and the number of aircraft in the system.

To sum it up, the total load imposed on the control position is made up of three main components:

L = L0 + L, + L2

In Figure 1, a typical load curve is shown with its three components. Where:

0 <t 0 _J

L Lo L, L,

IS

IS

IS

IS

the total load, the background load, the routine load, and the airspace load.

L 0 L --o

NUMBER OF Al RCRAFT

Figure 1 The three load components

2. The Variables of Traffic and Control

Before commencing the task of measuring the loads imposed on the control position we should clarify in our minds what are the basic variables that govern the be­havior of the traffic and the control functions. Further­more, we should satisfy ourselves that these variables are measurable and readily obtainable.

{l) The Traffic Variables:

(a) T~e _nu~ber of aircraft {N), the density and the d1stribut1on of the aircraft in altitude;

(b) The speed of the traffic {V) and the speed distribu­tion.

(2) The Rules - A given set of rules operates on the traf­fic in order to ensure its safety. These rules, namely, the separation minima, require a quantitative expression (a) that quantifies the amount of protected airspace that envelopes aircraft in the controlled airspace.

(3) The Airspace Variables - The flow of traffic is regu­lated not only by the rules of separation but also by the existence of an organized and highly regimented airspace. This airspace organization will be quantified by two basic variables:

(a) The size of the airspace under the jurisdiction of the control position (S), and

(b) The flow organization (g) . This last term (g) needs further clarification. Traffic assumes different shapes and forms. There is the ran­dom flow of traffic and then there is a highly orga­nized airway flow. The traffic tends to converge to­wards, and diverge away from terminal areas. Each form of flow organization will effect the control posi­tion differently and therefore we will need a quanti­fied expression of the flow organization.

(4) The Traffic Features - The traffic features characterize the traffic behavior in a given environment. They will give us additional information concerning the classi­fication of the users and their immediate mission. For example, in a given environment, most of the aircraft could be air carrier types flying mostly straight and level, whereas in another environment only a small proportion of the aircraft may be air carriers and most of these aircraft may be transitioning to or from a terminal area.

(5) Parameters - Finally, we need measures that relate the total traffic activity, the rules, the airspace and the traffic features to the effort which is required at the control position. These measures are: (a) The coefficient of routine load (K,) that quantifies

the effect of the traffic features on the control posi­tion, and

(b) The coefficient of the airspace load (K2 ) that quanti­fies the effort required to detect and resolve a con­flict situation.

3. Work and Load

The component of routine load (L,) is generated by every aircraft that traverses the sector. The control system is handling every aircraft irrespective of its relationship to other aircraft in the system. Thus, we could say that the amount of routine work required is directly proportional to the number of aircraft that traverse the sector.

This relationship between the number of aircraft and the work to be done is similar in many respects to any other problem involving "work to be done". For example, let us consider the case where chairs have to be moved from one room to another. There is a certain amount of work to be done and to move two chairs will require twice as much work as one chair.

However, when a time element is introduced, we are faced with a problem of a different nature. Going back to our simple example dealing with furniture moving, to move twenty chairs in one hour is a much easier task than to move the same number of chairs in five minutes. The total work accomplished is exactly the same in the two cases and yet moving twenty chairs in one hour is "a cup of tea" compared with accomplishing the same work in five minutes.

Thus the concept of "rate" has been introduced and in our particular case we will call the rate of doing work "Load". The routine load is that component of load which is directly proportional to the number of aircraft handled per unit of time.

But, what if the chairs are not equal? What if some are light and some heavy? Some easy to handle and some require special handling techniques? Or back to the air­space and the problem of routine load, what if the load imposed by each aircraft is somewhat different? In order to solve this problem, two things are required: (1) A stcndard unit of measurement, and

(2) a scale.

Given these two prerequisites we can determine "how heavy is heavy" and "how difficult is difficult"?

An establishment of a unit of measurement is nothing but a convention. We could, just to be difficult, determine by agreement that the standard unit of measurement will be an aircraft that lost one of its powerplants and is re­questing priority to a lower altitude. However, this is not practical and since there is no particular reason to be difficult we will agree on a very simple, common, standard unit of measurement: - a "standard aircraft" in the IFR system will be a scheduled aircraft that has penetrated the sector area of jurisdiction in a straight and level over­flight when no interaction with other aircraft is consi­dered.

For all practical purposes we consider all air carrier aircraft as standard aircraft. We should realize that the •rniformity of air carrier procedures and pilot capabilities is the prime characteristic that makes it a good standard measure. Therefore, other users of the airspace could be considered as good candidates for this standard category . However, for practical reasons we could not and will not examine each and every aircraft by itself but rather group them in accepted and well established categories . Thus, MATS aircraft should be considered as standard, whereas SAC aircraft, even on routine point to point flights, will be considered as "non standard".

The work which is generated by one standard aircraft is called DEW (Dynamic Element of Work) . That is, we decide that one DEW is equal to the work generated by one standard aircraft over-flying the sector in a straight and level flight when no interaction with other aircraft is considered. The unit of load is called DEL (Dynamic Ele­ment of Load) and one DEL is equal to the rate of doing

work of one DEW in one hour.

1 DEW l DEL = 1 h our

Now we have a unit of measurement and if we had a scale' we could "measure" every aircraft that traverses the sector in units of DEW. Add it up during one hour and find the routine load (L,) which is imposed on the sector.

4. The Coefficient of Routine Load

Unfortunately the distinction between standard and non -standard aircraft is not sufficient to express the amount of handling which every aircraft will require. Air­craft differ not only in the classification of the user but also in their immediate mission. Some aircraft climb and descend, whereas others fly straight and level. Some are being handed off vert ically to or from upper layer sectors, whereas others are handed off to adjacent sectors. Then again, some aircraft are handed off to or- from a terminal

9

area while others just overfly it . Finally, there are those that try to get the best of everything: VFR aircraft that request admittance to the IFR system while in flight (popups).

It is a fact that the traffic features have a repetitive tendency. We expect that if, in a given environment, 60 percent of the aircraft are air carriers on week days and 30 percent on weekends, that these features will repeat themselves from week to week. Then aga in, a sector ad­jacent to a big terminal area is expected to have more transitioning aircraft and certainly more aircraft going to or coming from the terminal area, and that these features are more or less constant and repeat themselves . These repetitive traffic features are, in fact, the characteristic features of the sector. In the high altitude environment, we will expect higher percentage of standard aircraft and in the vicinity of terminals it is only natural that a larger proportion of aircraft will climb or descend . Thus, if a "weight" can be assigned to any of the features, we will be able to determine the coefficient of the routine load (K,) for every sector and this coefficient, expressed in DEW per aircraft will be the "characteristic number" of the sector.

In Tobie l , the traffic features "specific weights" are listed. These weights are the results of extensive field sur­veys conducted in 13 ARTCCs.

"Specific % Feature Weight"

DEW

Po Standard aircraft 1.0 P, Non-standard aircraft l.l P, Vertica I hand-off + .26 P, Terminal aero hand-off + .38 P. Climbing and descending + .24 Ps Pop-up +l .3

Table 1 Tra ffic Featu res Weights

Undoubtedly various other features could be listed and their "weights" measured experimentally. However, these additional refinements might have a small and insigni­ficant effect on the determination of the routine load. Nevertheless, some traff ic features should be examined more closely and in particular the specific weights asso­ciated with military traffic. The traffic features can be given in percentages (P) . That is , P0 is the percentage of standard aircraft and P, = (100 - P0 ) is the p e rcentage of non-standard aircraft. Jn addition to this main classi­ficat ion P, is the percentage of aircraft handed off verti­cally; P3 is the percentage of aircraft to or from terminal areas ; P4 is the percentage of aircraft that climb and descend in the sector; and P5 are "pop-ups" requesting imprnmptu admission to the IFR system.

Now let us assume the following features: P0 = 50 per cent, P, = (l 00 - 50) = 50 percent, P, = 60 percent, P3 = 20 percent, P, = 55 percent, and P5 = 10 percent. This means that for every 100 aircraft that traverse the sector:

50 aircraft will generate 50 X 1.0 = 50 DEW;

50 aircraft will generate 50 X l.l = 55 DEW ;

60 aircraft will generate an additional 60 x = 15.6 DEW;

20 aircraft will generate an a dditional 20 x 7.6 DEW ;

10

.26

.38

55 aircraft will generate an add itional 55 x .24 = 13.2 DEW; and

10 aircraft will generate an additional 10 x l.3 = 13 DEW.

Summing up all the handling work we find that 100 air­craft generate 50 + 55 + 15.6 + 7.6 + 13.2 + 13 = 154.4 DEW or the average aircraft will generate 1.54 DEW.

Stated differently we say that the value of the coeffi­cient of routine load (K,) is : K, = l.54 DEW per aircraft. This value has been obtained by the traffic features which are unique to a certain environment. A different environ­ment will generate an entirely different value of the routine load coefficient. Consider for example the follow­ing high altitude sector :

Po 95% 95 x 1 95 DEW P, (100 - 95) 5% 5 x l.1 5.5 DEW P, 20% P,

P. Ps Total :

or, K,

0 25% 0

111.7

100

20 x .26 5.2 DEW

25 x .24 6.0 DEW

l 00 aircraft lll.7DEW

= 1.12 DEW per aircraft.

The only difference between the two sectors is the traf­fic features and yet, an average aircraft in the first case generates .42 DEW more routine work than an average aircraft in the second case. This difference in the amount of handling work required per aircraft is basically 0 func­tion of the environment.

5. The Routine Load

The routine work is an expression of work that has to be accomplished in the routine handling of the traffic. This however. does not indicate the load imposed on the control position. In order to determine the routine load we have . to introduce a time element that will expres; quant1tat1vely the rate of doing work. Thus,

N L, = K, -

T

Obviously, the routine load will increase when:

(1) the number of aircraft (NJ will increase ·

(2) the coefficien'. of routine load will incre~se; and (3) th~ average time that the aircraft are in the sector (T)

will decrease.

For example, consider a sector ad1· a cent to t · I . . a erm1na area where the coeff1c1ent of routine load is l.61 DEW per aircraft and the average time under cont I · 4 h . ro 1s . our. The routine load in this sector will be

L, =~N .4 = 4.25 N DEL.

On the other hand, a high altitude secto h · . . r aving a co-efficient of routine load of l 13 DEW per · ft d . · a1rcra an on average traverse time of .6 hour will yield

Ll = ~N = 1.88 N DEL . . 6

In Figure 2 the two cases are shown in 0 g. h. I f . 1 op 1ca orm.

It is evident that the sector od1.ocent to 0 te · I · rm 1no area 1s

expected to impose much higher routine load · ft per a1rcro than a high altitude sector.

We should note that the determination of the routinf; load (L,) has been achieved by using measurable quanti­ties. The variables of the traffic features, number of air­craft and time are obtainable by measuring the traffic activity in the airspace. In fact, any one of these variables could be readily obtained from tabulation and processing of the flight progress strips, these being the available re­cord of the traffic activity.

40

_, LU

0

0 <{

0 _, LU

z f-::i 0 er: 20

_,

10

5 10 15 20

N-NUMBER OF AC

Figure 2 The routine load in two typical sectors

6. The Airspace Load

We have defined the airspace load (L2 ) as that com­ponent of load which is generated by the requirement imposed on the control position to keep the aircraft sepa­rated in accordance with the accepted rules of separation. The question of whether one set of rules is safer or less safe than another set of rules is not our concern since we are operating in accordance with an established set of rules specified quantitatively by the separation minima.

Indeed our problem is reduced to a very basic que­stion: How much violation of the separation minima is expected to occur if traffic should proceed uncontrolied? Since these violations are defined as "conflicts" our pro­blem is to determine the number of conflicts that are ex­pected to develop in the airspace?

Cons ider the foiiowing analogy: A given number of billiard balls move at random on a billiard table. Every so often two or more balls will collide. Moreover, if the same number of balls should keep on moving at the same speed and maintain the same random movement, we could expect a certain average number of collisions per unit of time. Now let us see how this rate of collision is affected by the following variables:

(1) If the number of balls and their speed remains un­changed but the diameter of the balls is doubied we expect that more collisions will occur in a unit of time. In fact, it can be shown that, under conditions of ran-

dom movement, the average rate of collisions is direct­ly proportional to the diameter of the balls.

(2) If the diameter of the balls remains constant and their number is unchanged but we increase their average rolling speed, obviously the rate of collision will in­crease. Indeed, the rate of collision is directly propor­tional to the average rolling speed.

(3) Now, let us maintain the same average rolling speed and the same diameter of the balls but increase the number of balls on the table. The rate of collision will increase but, this increase is not directly proportional to the number of balls but directly proportional to the square of the number of balls. This undoubtedly re­quires some further clarification. It is evident that every collision involves a pair of balls, thus, between two balls we could have one collision. However, if three balls, A, B, and C, are present the following collisions are possible:

AB, AC, BC

Furthermore, if four balls, A, B, C, and D are present we expect that the following collisions are possible:

AB, AC, AD, BC, BO, CD

Evidently an increase in the number of balls increases considerably the number of all possible collisions. However, 'Ne are not interested in the number of all possible collisions but rather in the average value of the expected col.lision rate. This rate is directly propor­tional to the square of the number of billiard balls on the table.

(4) Finally we should consider the case where all the above mentioned variables are kept constant (diameter, speed, number of balls) but we have increased the size of the table. In other words the same number of balls are free to move in a larger area. The obvious answer is the right one - the rate of collision is inversely pro­portiona I to the size of the table.

From this analogy we could learn quite a lot about the traffic behavior in the airspace:

(1) the diameter of the billiard ball is the separation mi­

nima; (2) the rolling speed of the billiard balls is analogous to

the traffic speed; (3) the number of balls on the table is the number of air­

craft under control; (4) the size of the billiard table is equivalent to the size

of the sector; and (5) the average rate of collision of the billiard balls is

analogous to the average number of expected conflicts

between aircraft.

The concept of "average number of expected conflicts" needs some explanation. We will define "conflict" as a violation of the separation minima that would occur if no control action is taken. That is, a conflict is something that is only expected to happen but (hopefully) is always pre­vented in time. In fact, once a confl ict passes the expecta­tion stage and no prevention measures are taken, the flow of traffic is considered "unsafe" and an "incident" is de­clared. The average number of expected conflicts is a number that expresses the average rate of possible con·· flicts that might have occurred, under a given set of con­ditions, if no control action would occur.

11

We have defined the airspace load as this component of the control effort which is required in order to prevent the development of an expected conflict into an incident. In our analogy of the billiard game, imagine that we in­troduce a new element to the game. One of the players will always attempt to generate collisions by either in­creasing the diameter of the balls, their rolling speed, or the number on the table (he is blind-folded and not allow­ed to aim his throws). The opponent is provided with a tool that enables him to forecast collisions and prevent them. The load which will be imposed on the second player is, by our definitions, directly proportional to the average rate of expected collisions.

The billiard game analogy assumes a rondom traffic but in actual operational environment, various levels of organization are possible. For example, airway flow, inter­sections of airways, one directional airways, etc. Each of these flow organizations will affect the actual number of aircraft that ore expected to participate in a conflict in a unit of time. Therefore, we have to include in our expres­sion of the expected number of conflicts, a number that quantifies the flow organization and numerically relates the variables (a, V, N 2 and S) to the actual numerical value of the conflict rate (C). We call this number "the flow organization factor".

To sum it up, we have a basic expression for the aver­age number of aircraft expected to conflict in one hour, for any given condition of:

(1) rules of separation - a (nm/ac); (2) average traffic speed - V (knots); (3) number of aircraft under control - N (ac); (4) sector size - S nm 2 ; and (5) flow organization - g (non dimensional number).

The general expression for the expected number of con­flicts is:

2a V N2

C = ac in conflict per hour g s

The airspace load (L2 ) is the load which is expected to be imposed by the interaction of aircraft in the sector. The general expression of this load yields:

2 K2 a V N2

L, = g S

Where K, is the coefficient of the conflict load and ex­pressed in DEW per aircraft. The value of K, has been obtained by field surveys involving about 300 controllers in 10 field facilities:

1 conflict = 2.8 DEW K, 1.4 DEW per AC in conflict

The expected number of conflicts (C) is expressed in ac/hr. and therefore the air space load L2 is expressed by DEW/ hr. or DEL.

7. The Control Load

In summing up the expressions for L, and L, we get

N 2 K, a Y N1

L = K, T + gs In Table 2 we have listed some information concerning

three typica I sectors:

12

(A) A sector adjacent to a terminal area (B) Low altitude emoute sector (C) High altitude sector

Sector A Sector B Sector C Symbol

Area 4000 nm 2 8000 nm 2 12000nm2 s Av. Time .4 hr. .6 hr. .9 hr. T Av. Speed 220 knots 250 knots 350 knots v Flow Organization 9.5 12.0 10.5 g

Table 2 Traffic features and variables in three typical sectors

Standard ac 75% 40% 95% Po Nonstandard a/c 25% 60% 5% P, Vertical H.0. 30% 25% 15% P, Terminal H.O. 80% 0 0 pl Climb/descend 75% 30% 20% P. Popups 10% 10% 0 Ps

Traffic Features

Coeff. of L, 1.8 DEW/AC 1.37 DEW/AC 1.1 DEW/AC K,

Routine load

Airspace load

Resu!ts

4.5 N DEL 2.28 N DEL 1.21 DEL L'

.081 N> DEL .063 N 2 DEL .078 N> L,

Figure 3 illustrates the load imposed on the control position ~y the three sectors. We can see, for example, that 10 a1rcraf! will impose:

_J

'""' D

D 4'. 0 -'

in Sector A in Sector B 1n Sector C

110

100

90

80

70

60

50

40

30

20

JO

53 DEL 29.5 DEL, and

only 20.0 DEL

--'---'----'--' _LI I I I _)__ J 5 I 0 -~_,I 5---'--'---'-_J__ 2 0

NUMBER OF AIRCRAFT

Figure 3 The total load (l) in three typical sectors

The differences between the loads imposed on these three " '"''"''o"" typical sectors is due to the differences in the traffic fea-f r----------­tures, the traffic variables, the airspace and the flow organization.

h Figu_re _4 illustfrahtes how a characteristic load curve and r t e variations o t e traffic during a typical day gives us a complete picture of the amount of load imposed on the control position at any time. Furthermore, if we accumu-late the load from the beginning of the watch to the end (8 a.m. - 4 p.m.) as shown in Figure 5, we will get the amount of total control work performed by each watch in units of DEW.

300

250

200

~ w 0

:.:: 150 a: 0 3::

3:: 100

50

Figure 5

CUMULATIVE LOAD DISTRI BUT 10 N IN A BUSY DAY

B 9 10 11 12 I 2 3 4

AM

f..-- Fl RST WATCH •I•

5 6 7 B 9 10 II 12

PM SECOND WATCH --j

8. Sector Design

There is a distinct difference between the routine load L, and the airspace load L2 • The airspace load is generat­ed by the total traffic activity and basically is a reflection of the desires and intents of the flying public to go from place to place. In fact, the total traffic activity as reflected

Tl~f

Figure 4 A & B

.. , r~ ' ' : : '

•-,

N-NUM9EROF&./C

by the interaction between aircraft (C), is completely in­dependent of the way we select to control traffic. On the other hand, the constraints imposed on the system gene­rate a requirement for a limited size sector and the routine load is a quantitative expression of the load imposed on the control position by the system limitations.

Following this line of reasoning we could define the effectiveness of our system as the ratio between the "ob­jective" load imposed by the traffic activity and the total load (L):

The effectiveness increases with the average track length {s) for any given aircraft density. In other words, the best sector design will be achieved by maximizing the value of s. This criterion could be considered as necessary and sufficient for optimizing the design of a sector when random traffic is considered.

However, airway traffic requires additional considera­tions. Maximizing EL, by itself, is not sufficient and some other conditions have to be defined and applied.

The most efficient sector will be achieved by maximiz­ing the following ratios:

(a) S/s2 where s is the average track length

(b) s/2.s where 2.s is the total airway length covered by the sector, and L,

(c)-L

We will refer to ES = S/s2 as the area effectiveness, E, =

L, h s/2.s as the airway effectiveness, and to Ei. =-L- as t e

load effectiveness. The total effectiveness of the sector is:

where the values of E,, ES and Er. are normalized to 100% between their minimum and maximum values.

Maximizing the total effectiveness of the sector yields a very interesting result. The optimal sector (E = Max) is achieved when each airway length is proportional to its average density. That is, if one airway has an average density of 6 aircraft per 100 nautical miles and another airway has an average density of 12 aircraft per 100 nau­tical miles. The length of the denser airway will be twice as long as the length of the scarcer one.

13

Th is method, however, does not define the size of the sector. Figure 6 shows the application of the principle of proportional parts in a simple schematic airway structure. We can observe that any proportional increase in the air­ways segments will, indeed, define a new sector size by a contour of load level.

In order to determine the size of the sector we have ta determine the capacity of the system. Given a capacity level in units of load (DEL) the optimal size of the sector can be determined by maintaining a balance between the load imposed on the control position and its capacity. The importance of the principle of proportional part::: is that we can design the best sector for any given level of capa­city. Thus, an improved environment and better machine aids at the control position will yield new and improved sectors if the traffic activity is properly measured, the con­trol loads determined, the sectors are designed in accord­ance with the principles of sector design and their size is matched to the system capacity.

Figure 6 The principle of proportional parts

Bo Lundberg received Monsanto Aviation Safety Award

Bo K. 0. Lundberg, director general of The Aeronau­tical Research Institute of Sweden (FFA), has been chosen by the US aviation writers to receive the Monsanto Avia­tion Safety Award for the "most significant and lasting contribution to aircraft operating safety during 1963".

Lundberg, an international authority on aircraft struc­tural fatigue and the statistical control of flight risks, has been presented the sculpted bronze trophy at luncheon ceremonies May 25, the opening day of the Aviation I Space Writers Association week-long 26th annual meet­ing at Miami Beach, Fla.

The aviation writers based their selection of Lundberg on his application of broad concepts and mathematical theory to the problem of preventing catastrophic struc­tural failure by fatigue and his Guggenheim Memorial Lecture of 1963 entitled "Speed and Safety in Civil Avia­tion" . Widely recognized as realistic and reasonable, it presented a comprehensive ond astute analysis of air safe­ty problems and proposed a stati stical method for identi­fying control lable risks and reducing them to acceptable limits.

His purpose, Lundberg has said, is to foster the con­tinued sound growth of commercial aviation by further improving its already excellent safety record and thus encourage wider public acceptance of air travel.

The award, es ta bl ished in 1957 by Monsanto Company

14

"to acknowledge and encourage progress in aviation safety", is presented each year to an individual selected

by the aviation wri!ers from . candidates nominated by on international committee of high-ranking aviation officials.

Lundberg hos made pioneer contributions to the im­proveme~t of the ?viation industry for more than 30 years, as test pilot, desrgner and researcher in the fatigue of aircraft structures and statistica l control of flight risks. He become director general of the FFA in 1948, after serving four years as chief of its structural department. The author of many scientific papers, Lundberg has received numer­ous international honors, notably the Swedish Thul in Me­dal in both silver (1948) and gold (1955), and the Flight Safety Foundatron Award for 1960. He is one of the Foun­der Members of the International Council of the Aero­nautical Sciences.

Other recipients of the Monsanto Aviat ion Safety A:-rard have been: forome Lederer, managing d irector, Flrght Safety Foundatron, Inc. (1957), Maj. Gen. Jose h D. " Smokey" Caldara, then director of flight safety res:arch USAF (1958), E. R. "Pete" Quesada, then FAA Administra~ tor (1959), E. S. Calvert, sen ior principal scientific officer, Royal Aircraft Estoblishme_nt, Farnborough, England (1960), Otto E. Krrchner Sr., arrlrne safety advisor, The Boeing Company (1961) and W i lliam Littlewood, vice president of equipment research, American Airlines {1962).

Springtime in Europe Impressions of an American Observer

by Tirey K. Vickers Hazeltine Corporation

During the last Officers Meeting at the Brussels Conference Honorary Secretary Hans W. Thau said: "Tirey Vickers is IFATCA 's ambassador to the United States." Indeed, more of our American colleagues, have learned about the Federation from Tirey Vickers' contributions to the U.S. ATCA Journa l than from any other source. In the following article, which appears at the same time in the ATCA Journal, Vic reports about the 1964 Annual Conference , the Hannover Airshow, and the Concorde SST project. Ed.

Brussels

The Belgian Guild of Air Traffic Controllers hosted the Third Annual Convention of the International Federation of Air Traffic Controllers (IFATCA) this year. The three­day meeting got under way on April 21, at the Palais des Congres in Brussels. Over 130 representatives and ob­servers from 23 different countries attended the meeting. Three more ATC associations joined IFATCA this year: Italy, Uruguay, and Canada. One former member asso­ciation, Central Africa, had to suspend operations when its territory split recently into three separate nations.

The convention reviewed the work of the association during the past year. One of the most important tasks was the preparation of guidance material which had been re­quested by ICAO, regarding the proposed international standardization of radar control procedures. Other guid­ance material prepared by IFATCA this year covered such subjects as l 0-centimeter radar, bright displays, closed­circuit TV, air/ground data links, integration of civil/mili­tary ATC operations, and the simultaneous use of parallel runways.

It was decided to continue work on these subjects dur­ing the coming year. In addition, the French Air Traffic

Brussels Area Control Centre

"Coffee break" in the Pa lais des Congres

Control Association was asked to begin a similar study of the ATC factOl"s involved in supersonic transpor·t oper-a­lions.

An appeal was made for all association s to submit operational articles for the IFATCA magazine "The Con­troller". Apparently, active controllers al I over the world share one tendency: after· slaving all day over a hot flight progress board 01- radar scope, they are not particulady eager to sit down and write a magazine article about arr traffic control Thus although these men are closer than

. ' I anyone else to the present ATC system, and are the rea ex perts in the profession, very few people outside .their own local facility ever get the benefit of their expenence

and rnsights on the subject. The last day of the IFATCA convention was given over

to local tours of aeronautical interest. One tour went to the Brussels Aii·port , where delegates in spected the new

quarters and equipment o f the ATC facilities. One ~f th.e most interesting features of the Brussels Center radar rs the automatic display of ADF fixes on the radar indi cator. When an air·craft trnnsmits for an ADF fi x, video lines pop out from the three ADF sites, to intersect on the scope

face and pinpoint the transmitting target . . Tour members were given demonstration flrghts rn the

Decca Navigator Company 's twin-engined " Eli zabethan "

15

airliner. This aircraft, which formerly belonged ta the King of Morocco, has one of the most lush interiors of any fly­ing machine in existence. The cabin is also fitted out with multiple HARCO and Decca pictorial navigation displays,

so that all passengers can trace their progress precisely across the countryside, while wondering wistfully how simple ATC could be, if all IFR aircraft were equipped with an area-coverage, multi-track, pictorial navigation capability.

A second I FAT CA tour visited the SABCA factory at Charleroi, where delegates watched the assembly and

flight testing of F-104 interceptors for the NATO forces. A third IFATCA tour visited the Von Karman Institute

of Fluid Dynamics at Rhode-St.-Genese, where every year,

125 students from the free world participate in advanced studies in aerodynamics, and jet engine research projects. Visitors inspected the wind tunnels and other laboratory installations. They watched, in slow motion in a water tunnel, the weird flow reversals which occur when a jet engine experiences a compressor stall. They also watched the generation of shock waves and other phenomena,

during demonstrations of the supersonic (Mach 1 to 3) and hypersonic (Mach 5 to l 0) wind tunnels .

One of the nicest features of any I FAT CA convention

is that it brings together in friendly personal contact, ATC personnel from so many different countries. Social evsnts connected with this year's convention included two spon­sored luncheons, three receptions, and an afterburner party. The party was held on the last night of the conven­tion, in an old moated castle near the Brussels Airport. The

castle dates back to 1472 and the plumbing soon after­

wards, but a rousing time was had by all. The entertainment was provided by the Schoenewald

Cherry Pickers, a jazz band composed entirely of Rhein UACC controllers. Stationed in a sparsely-settled area of West Germany, these boys took up music to help pass the long winter evenings. Legend has it that their rehersals

are held in a remote hunting lodge, deep in the Hunsruck­mountains. They do a professional job; and if you have never heard American Dixieland belted out by a band of German controllers, inside the rock walls of a fifteenth­

century Belgian castle, you just don't know what you've been missing.

Mike Pearson explains the "Ghost Beacon" of the Decca Navigator System during demons~ration flight

* * * Hannover

Every two years, the German aircraft industry stages an exhibition of its wares, at the Hannover Airport. This year it was held from April 24 to May 3, and attracted many foreign exhibitors as well. Three huge show build­ings were filled with static displays of aircraft, engines, mock-ups, components, as well as spacecraft and elec­tronic airborne and ground equipment. Most of the ex­hibits were from the western European countries, Canada, and the United States.

Outside was a romp-ful of the latest civil and military aircraft, from the huge Transall military transport to the tiny Dornier one-man helicopter. Most of the aircraft were demonstrated during the show. Three trends were ap­parent: the progress in European V/ STOL developments, the ri sing importance of general aviation in Europe, and the v itality of the Germon aircraft industry itself.

While the United States has been shooting its wad in the space race, th e European aircraft industry has been giving cmeful attention to the development and refine­ment of ver t ical takeoff a nd landing (VTOL) and steep tak eoff and landing (STOL) aircraft. There are two rea­son s why V/ STOL is a no turnl development, for· Europe. In w m ti me, the ab ility to utilize a tremendous number· of

16

potenti_al landing strips or pads hos immense military value rn an area where the enemy is close enough to

quickly paralyze all the large airport installations. In peacetime, the ability to utilize small landing facilities

close-in to city c:nters offers the best chance of reducing inter-crty travel trmes, where the cities ore relatively close together.

Many different V/STOL designs were displayed at Han­nover. Hit of the show was the VJ-101, a little German fighter which combines Mach 2 capability with vertical takeoff and landing! About the size and shape of an F-104, the VJ-101 has a swivelling engine pod on each wing tip. Each pod contains two jet engines. The pods are tilted vertrcally for vertrcal takeoff and landing; and are tilted horizontally for forward flight.

The need to re-supply a dispersed VTOL tactical air force in the field hos generated the logistic requirement for VTOL transports. Dornier (Germany) and Fiat (Italy) exhibited such desrgns, rn model form, at Hannover.

The number of general aviation in Europe is still re­latively small. However, the continued economic boom

and the growing need for fast executive transport is start­ing to change the picture. As a result, a large variety of

European and American business aircraft filled the ramp at Hannover.

We continue to marvel at the way West Germany has bounced back, since World War 2. The West German air­craft industry has shared in this resurgence . Besides the V/STOL developments mentioned above, nearly all Ger­man aircraft manufacturers exhibited plans or prototypes of new executive jets, or light jet transports. Most radical in appearance is the new Hansa 320, a twin-jet business aircraft with swept-forward wings.

Although we had a press pass, we saw very few new developments in the air navigation and ATC field, at Hannover. Mast interesting, however, was the Trans radar FAB 6072 radar remoting system, which was exhibited by Standard Elektrik Lorenz (SEL), an affiliate of IT&T. The Transradar system permits radar data to be transmitted several hundred miles, over telephone or broadcast lines . At the radar site, the returns from each sweep are stored in a series of 512 condensers, each of which corresponds ta a different increment of radar range. Periodically, the stored data is digitized and transmitted down a telephone line to the ATC facility. Here the various data bits go first to a buffer storage, and then are reassembled into a radar picture on the PPI scopes.

The Transradar design approach is more simple and cheap than the radar remoting methods used previously. It is perfectly adaptable to the variable pulse repetition rates which are used on certain ATC radars . Because dif­ferent echo signals from the same target are added to­gether before transmission, and because random noise pulses don't add up the same way, most of the random noise returns never get remoted . The result is a higher signal/noise ratio, which produces a cleaner radar display on the remote radar scopes.

At Hannover, SEL showed a model of their new Dopp­ler VOR station, which is claimed to give a 10-to-l im­provement in azimuth accuracy, as compared to a con-

SEL Transradar, for in stol lotion at PPI site

vent!onal VOR. Any conventional VOR receiver can use the Doppler VOR transmission in the conventional way. However, the increased accuracy of the new ground sta­tion cannot be exploited without modifying the airborne receiver.

* * * Bristol

When you step inside the gigantic glass-doored as­sembly building of the British Aircraft Corporation, near Bristol, England, you can feel the tingle of excitement in the air. Taking shape in this building, is what may be the most significant aircraft - or the most expensive mistake - of the jet age. Here, in full-scale mockups of plywood, battens, and cardboard, engineers and technicians are laying out the lines of the world's first supersonic trans­

port - the Concorde.

Nearby, there is o clatter of rivet guns, as sections of th e metal fuselage are being assembled for the structural tests. The cross-sections are round, except for a foot-wide flat section on each side, for the passenger windows. The windows will be perfectly flat, and flush with the skin.

Down on the hangar floor, engineers in white smocks are swarming over a sleek little single-jet aircraft - the BAC 221. Looking like a late-model interceptor, the 221 is actually a 3/10 scale flying model of the Concorde, as far as the wing is concerned. The 221 will be flown in an ex­haustive test program, in checking and refining the flight characteristics of the Concorde, before the full-sized SST ever leaves the ground. You look at the thin, curving, dart­shoped delta wing of the 221; then you suddenly realize what a radical aircraft the Concorde is going to be.

The fuselage of the Concorde w ill be 184 feet long . That's forty feet longer than the largest 707 in use today. However, the wing span will be only 84 feet. Tha t's eleven

feet less tan the span of a DC-3!

The Concorde will have a lean-and-clean fuselage, which will accomodate only four passenger seats abreast, even in the long, tubular tourist section. Th e nose will taper gracefully to a long, pointed tip. During low-speed operations, the entire nose section will be hinged down­wards about ten degrees, to expose the conventional wind­shield and let the pilots see w hern they are going. For· super·sonic flight , the nose wi ll be moved up into a stream­lined position, and a large heat shield wi ll cover the w ind­shield. The heat shield will contain two " eyebrnw" wind­ows. These will allow the pilots to look slightl y upwards and outwards, in a forward d irection - but not direc tly

ahead. A winch will be p rovided to crank the nose down by

hand, in case the nose actuator becomes ino 1Je rntive . Should the winch also become ja mmed, the air·craft w ill still be capable of making a complete ly automatic b lin d

landing on the ILS. When you get inside the mock-up, you frnd tha t th e

pilot's cockpit is quite smoll for a transport. There is jus t

17

enough room, belween the pilot seats, far the throttle con­trol pedestal. Ta get into either seat, you have to step over the pedestal; it's like crawling into the front seat of

a Thunderbird convertible, from the rear seat. The pilot's instrument panel is surprisingly simple. The

flight engineer, directly behind the pilots, will have many more items to look after. In the center section of the pilot's instrument panel is a large circular pictorial navigation display. Whether it will be driven by Doppler, Dectra, or an inertial system, has yet to be decided; but hardly

anyone expects it to be VORT AC. On each side of the cockpit, near the nosewheel steer­

ing handle, is a little TV monitor. The pilots will be sitting so far behind the pointed nose, ond so far ahead of the nosewheel, that for taxying purposes it is planned to give them a TV picture (from a forward-looking camera in the belly) which will show them where the nosewheel 1s, in

relation to the stripes on the pavement. To avoid sonic damage to ground structures, it is in­

tended that the aircraft will go supersonic, and will de­bang again, at or above 40,000 feet . When the aircraft

exceeds the sound barrier, the center of pressure moves back toward the trailing edge. Compensation for this trim change will be made by transferring fuel from the for­

ward tonks to the rear tanks . Should the pilot decide not to go supersonic, the Con­

corde will still be able to fly approximately the same dist­ance (for its fuel load) subsonically, at an altitude of about 36,000 feet; however, the trip will require about

twice the usual time to complete. The Concorde will hove no speed brakes or flaps. The

exlremely narrow wing will not stall like a conventional wing. Technically, you might describe a Concorde ap­prnoch os a power-controlled mush. Because the aircraft will be flying ot a high angle of attack, on the reverse side of the powe1· curve (where the power required varies inversely with the speed) , it is planned to use auto-throttle

on o il opproaches. The Concorde will touch down at 145 knots, if you rnn call that touching.

18

Concorde Mock·up

One ATC problem which may be increased with Con­corde operations is the trailing vortex hazard. For any given airspeed, the maximum vortex velocity is directly proportional to the span loading (aircraft weight/wing span). Based on a takeoff weight of 330,000 pounds and a wing span of 84 feet for a Concorde, as against 300,000 pounds and 142 feet, respectively, for a Boeing 707 Inter­continental, it is expected that the vortex velocities of the Concorde will be about 85% higher than those churned up by the 707. Thus, it will probably be necessary for con­trollers to allow a much longer time for the disturbance to subside, before clearing another aircraft out behind a

Concorde.

US ATCA's Ninth Convention

"ATC Tools For Tomorrow", will be the theme for the

Ninth National Meeting of the Air Traffic Control Asso­ciotion.

Scheduled for October 5-6-7 in Atlantic City, N. J . at the Chalfonte-Haddon Hall, the Convention is expected to attract 1500 controllers and aviation leaders. Represen­tatives of the civil airlines, the military aviation services, the Federal Aviation Agency and manufacturers of air traffic control equipment will attend, as well as many of the Association's 7000 air traffic controller members.

Attention will be focused on "In Service Improve­ments"; "System Modernization" - its impact on the skills i-equired to operate a modernized traffic control system; and the necessary training to satisfy skill level require­ments .

The Annual Air Traffic Control Equipment Exhibit will affo1·d membe1·s of the manufacturing industry an oppor­tunity to present equipment expected to be a part of the modernized system to air traffic controllers and pilots, who will ultimately use the "ATC Tools For Tomorrow".

ICAO reports on Air Transportation in 1963

Preliminary returns indicate that the scheduled airlines of the 103 member states* of the International Civil Avia­tion Organization had an overall operating profit of about S 165,000,000 (US) in 1963, that is to say, about 2.40/o on operating revenues of S 7,125,000,000 - according to o report issued by the ICAO Council. This compares to on overall operating profit of S 97,000,000 in 1962, and an operating loss of S 118,000,000 recorded for 1961.

The Council's annual report to the ICAO Assembly, which describes the progress of civil aviation in 1963 os well as listing the work done by !CAO, also states that the number of tonne-kilometres (or ton-miles) performed by the airlines lost year was more than double the 1957 figure, and is numerically larger than the combined total of scheduled airline traffic produced in the six early post­war years, 1946-1951. From the point of view of traffic increase, 1963 was an overage year; the increase over 1962 in tonne-kilometres (or ton-miles) was 12.00/o, and the overage rote of growth from 1953 to 1962 was 12.1 %.

Extracts from the Council's report on the subjects of airline safety record, and technical trends ond develop­ments, follow:

Airline Safety Record

The passenger fatality rate per 100 million possenger­kilometres, at 0.47 (0.76 per 100 mil lion pcssenger-miles), is the lowest ever recorded for world scheduled air ser­vices as o whole. This is the third successive year in which the rote has shown a substantial reduction, and indica­tions ore that the long-term steady downward trend in this rote, which seemed to have been interrupted between 1955 and 1960, hos once more been resumed. Th is sat is­factory trend in the occident rote should not, of course, give rise to ony complacency, since there were still about two serious crashes per month on the overage throughout the year, killing o total of nearly 700 passengers and in­juring many more. Nevertheless, the further reduction of the 1962 occident rote, which was already low in com­parison with previous years, is undoubtedly on achieve­

ment that con be regarded with satisfaction ...

If we consider the question of passenger safety -which is the most important objective for those concerned with public air transport - it is satisfactory to observe !hot the new jet aircraft, which are now responsible for about two thirds of the passenger-kilometres performed on scheduled air services, account for only slightly more than one third of the passenger fatalities. Exact statistics are not available, but it would seem clear that the gradual introduction of the large turbo-jet airliners hos been an important factor in the reduction of world accident rates.

Technical Trends and Developments

Noi s e - The problems of aircraft noise continued to defy ony simple, readily available solution, in spite of concentrated efforts in this area. Noise abatement proce­dures continued to be imposed through special toke-off and landing techniques that do not compromise flight safety. As the second generation of jet transports, with

The USSR and the People 's Republ ic of China are not members of

ICAO.

engines mounted oft 1n or on the fuselage (such os the BAC-111, Boeing 727, Trident and Vickers VC-10) progress­ed in their flight test and certification programmes, it was encouraging to learn that the noise levels hove been appreciably reduced by duct design, use of sound-proof­ing material and noise cut-off as a result of the un ique positions of the engines and wings ...

C a r r i o g e o f f I i g h t r e c o r d e r - The trend towards more widespread installation of flight recorders

in aircraft, particularly in turbine-engined aircraft, conti ­nued both as o result of voluntary programmes in it iated by operators and as a result of mandatory requ irements of certain Stoles. The value of these instruments in a ircraft occident investigation was amply demonstrated on several occasions during the year. Their value lies, however, not only in provid ing clues to occident causes but also in the continuous monitoring of doto on incidents and trends, with the object of enhancing the a lready high standard of flight operations and of perm itting thorough investigation of incidents before they assume the proportion of acci­dents. These instruments usually record, as a min imum, time, airspeed, altitude, vertical acceleration and heading, but it hos been suggested that recording should be ex­tended to include such further parameters os attack angle; pitch, yaw and roll rates; angle of bank; and the posit ions of the major controls ...

S n ow o n d s I u s h o n r u n w o y s - Stud ies con­tinued on the operntionol effects on both landings and toke-offs of accumulation of water or slush on runways. These studies emphasized the prob lem of maintain ing di­rectional stabil ity and braking effectiveness due to pneu­matic tire hydroplaning or aquap laning. Experience hos shown that this hos increased w ith the advent of heavier aircraft with foster toke-off and landing speeds ...

Re Ii ob i Ii t y - Increasing reliance was placed on the continuous and correct operation of many elec­tronic devices in aircraft, which in turn places greater emphasis on the need for a high level of component reli­ability. The introduction of solid-stole devices such as the trans is tor hod a I ready assisted in th is respect; neverthe­less, new techniques - many of which were born of mi­litary necessity - promised to be of great benefit to civil aviation. One such technique is m icro-miniatur izat ion. The ability to manufacture complex e lectronic systems wh ich are light in we ight ond occupy o minimum of space is in itself attract ive; however, on add it ional character istic of this particular technique which is l ikely to be even more significant is the expectation of o very substantial increase in the mean time between failures, os compared w ith that for similar circuits based on conventional construct ion techniques .. .

Meteorology - As in 1962, progress in the use of electronic computers for preparing w eather analyses and forecasts continued. In addit ion, facsimile tran smis­sions were mode on a slowly increasing scale far the d is­semination of computer-based ana lyses ond forecasts -a development in the process of centralization wh ich can be expected, ultimately, to relieve mony meteoro log ical offices around the world of o la1·ge part of their chm ting and forncast ing work, while ot the some time result ing in

higher standards of forecasting for aviation

19

Pioneer Award

for

Dr.-lng. Ernst Kramar

On 13th May 1964 Dr. Ing. Ernst Kramar was presented with the "Pioneer Aword in Aerospace and Electronics", at the IEEE Conference in Dayton, Ohio.

This award is made by the Professional Group on Aero­space and Navigational Electronics (PTGANE) for major research achievements accomplished at least twenty years ago, which must have proven their significance througn progressive development.

Dr . Kramar, Director of Standard Elektrik Lorenz AG, received this high award for his fundamental resea1ct1 work on radio navigation and, in particular, electronic landing aids.

Furthermore, Dr. Kramar has been appointed Honorary Professor at the Technische Hochschule Karlsruhe, in re­cognition of his many yeors lecturing.

As long ago as 1932, Professor Kramar had demon­strated that VHF could usefully be applied in directional beacon systems, and on this principle an approach beacon was installed at Berlin-Tempelhof airport in 1933. This VHF-beacon was a major component of the Lorenz land­ing system. It is quite remarkable that, even in 1937, the major European airports had been equipped with this system, at a time when the United States was still using MF/ HF systems.

For his successful research and development work Pro­fessor Kramar received in 1937 an award from the Lilien­thal Society for Aernnautical Research.

Big Picture - Little Picture*

One obstacle to progress in air traffic control is the fo ct that those i-esponsible for the "big picture" do not know enough about the "little picture" and the "little pictui-e " is ve1·y definitely affected by the decisions made on the "big picture" leve l. "Big picture" planners are prone to di scount " little picture" problems and the weak­ness is in the fact that th e service is provided to the pu ­bli c at th e " littl e picture" level . The moment of truth and ve 1·ification of the wisdom of " big picture" planning occu r at th e " littl e pictu1·e" level , but the "big picture"

Repri nted from the ATCA-Bu l letin by kind permission of the Editor .

20

In the same year the VHF landing system was, at the invitation of CAA, demonstrated to a great number of US aviation experts in Indianapolis, as a result of which Federal Laboratories of ITT undertook to modify the system to meet USA requirements.

In 1938 the British Company Standard Telephones and Cables Ltd. started production of this equipment under the name "Standard Beam Approach" (SBA) .

In the 1940s Professor Kramar was engaged in high­accuracy long range navigation systems, and the result of these studies were "Electra" and the Lorenz "Sonne" the predecessor of today's "Console". '

From 1957 Professor Kramar concentrated his research work on Doppler VOR and large aperture VHF-DF. These· studies have led to the development of the "Doppler Twin Beacon", a navigation aid of high accuracy, which may have special importance in the field of blind landing tech­niques.

In appreciation of his contributions to navigational developments Professor Kramar was awarded the first "Goldene Ehrennadel" by the Deutsche Gesellschaft fUr Ortung und Navigation in 1962.

Professor Krar_nar is a Member of a number of Study Groups, and Chairman of others, in Nachrichtentechnische Gesellschaft, Deutsche Gesellschaft fUr Ortung und Navi­gation, Wissenschaftliche Gesellschaft fUr Luftfahrt and the Institute of Electrical and Electronic Engineers. '-on

planner is not there. When "big picture" planners fail to meet the need at the "little picture" level, they are failing 1n the accomplishment of their responsibilities.

The individual at the "little picture" level, is interested in the immediate problem at hand. He cannot appreciate the high-level coordination, budget and legislative pro­blems because he has not been a part of it, but again lets repeat that the "little picture" level is where the validity of "big picture" plannin.g is measu1·ed. There is not enough liaison and understanding between the two.

Notes on the Employment of Dual Runways by Tirey K. Vickers Hazeltine Corporation

Airport Design

The minor increases in traffic flow which are sometimes gained by the elimination of certain bottlenecks in the air traffic system often serve to uncover another bottle­neck somewhere else. If this process is carried far enough, the final limiting factor in the capacity of the system usual­ly turns out to be the airport itself.

Two basic methods are available for increasing the capacity of an airport. The least expensive method is to reduce the time required for each successive operation. This includes the reduction of runway occupancy times through the employment of adequately-lighted high-speed runway exits, high-speed runway entries, and dual-flow taxi routes; it also includes the use of more efficient air­craft spacing procedures (as described in the October 1962 issue of the IFATCA "Controller" Magazine).

The second method of increasing airport capacity is to add an independent runway. The word "independent" is emphasized, for any resulting gain in capacity will de­pend on how much of the time the additional runway will allow an additional traffic operation to be in progress simultaneously. It is difficult to exceed 45 IFR operations per hour on a single runway which has to be shared for both landings and takeoffs. To sandwich any between two instrument approaches usually requires that the arrivals be spaced 6 or more miles apart on the final approach.

If take-offs can be made on a runway which does not converge with either the landing path or the missed ap­proach path, the approach interval can be reduced and the capacity will be increased accordingly. With a com­pletely independent runway for take-offs, for example a "V" -shaped layout with takeoffs toward the open end of the "V", it is reasonably possible to increase the airport capacity up to about 60 total operations per hour (30 in, 30 out).

The trouble with a diverging runway is that it becomes a converging runway if you have to reverse the direction of traffic flow. Under such conditions, its potential inter­ference with the missed approach path severely limits its usefulness in IFR conditions.

One answer would be to provide a third runway in an "N" or "IX" configuration, so that an independent, diver­ging take-off runway would be available regardless of the landing direction. However, a more economical me­thod of securing bi-directional independent take-off capa­bility would be to install a single take-off runway parallel to the landing runway. This brings up a significant que­stion - how far apart should parallel runways be spaced?

If the anticipated arrival peaks will exceed 30 aircraft per hour, the layout should be designed to permit dual approach operations . In this case, present standards in the United States require a minimum spacing of 5000 feet between parallel instrument runways.

If the arrival peaks are never expected to exceed 30 aircraft per hour, the airport can be laid out on the pre­mise that only one runway at a time will ever be used for instrument approaches. In this case, if the land available for airport expansion is severely limited, the parallel run-

way can be considerably closer than 5000 feet to the land­ing runway . Although this reduced spacing does not pro­vide completely independent operation of the take-off runway, it usually allows ATC to clear one departure for every instrument arrival. In this case, each departure must be fired off within the interval between the time the Num­ber One arrival is in sight with landing assured, and the time the Number Two arrival reaches a point two miles from the airport.

Recent U.S. studies of the trailing vortex patterns pro­duced by aircraft in flight have established the fact that such vortices tend to spread outward when they reach the ground, and could become a hazard to other aircraft on a nearby runway, under certain conditions. This factor has led to a recommendation that parallel runways always be spaced at least 2500 feet apart, to avoid the most serious aspects of this problem.

The trailing vortex problem is, in itself, a strong reason for the establishment of a parallel runway, for any airport which needs to accommodate even a moderate traffic demand from a mixture of light and heavy aircraft. Parti­cularly in VFR conditions, the segregation of light aircraft in one lane and heavy aircraft in the other tends to mini-111:ze the tra i ling vortex hazard to the light aircraft. It also simplifies the aircraft spacing problem, by reducing the speed differential between successive aircraft.

Dual-Approach Research

Back in 1952, background studies for dual-approach operations were conducted at the CAA Technical Deve­lopment Center at Indianapolis, using the dynamic ATC simulator. The purpose of this project was to develop simple and practical procedures for the operation of a parallel-runway dual-approach system. It was assumed that the parallel lanes were one statute mile (5280 feet) apart, and that an individual radar controller fed traffic into each lane.

The simulation tests showed that the turn-on to the final approach path was the most hazardous portion of the entire operation, from the ATC standpoint; an aircraft which overshot this critical turn became an immediate menace to traffic in the opposite approach lane. How­ever, once an aircraft was established on its assigned localizer course, there was very little chance that it would deviate dangerously from the intended path to the touch­down point. The latter observation was backed by a large number of recordings of actual ILS approaches, which showed that excursions from the centerline of the loca­lizer course tend to get progressively smaller and smaller, as aircraft proceed down the final approach path.

The main problem to be solved was: how to eliminate the collision hazard at the turn-on point, while feeding dual lanes at maximum capacity? The first tentative solu­t ion was to stagger the turn-on points, as shown in Figure l . Tests quickly proved that this procedure eliminated only

half of the potential collisions .

21

Shading indicates most likely overshoot area

Orig inal Layout Staggered Turn-On Points 3 Mile Turn-On Separation

Figure l In i tial Procedures tested in 1952 Simulation Trials

Another proposal was for each controller to take care­ful note of aircraft starting into the opposite lane, and to keep his aircraft at least three miles away from such air­craft, at the turn-on point. Tests showed that the need for maintaining three miles separation from all other aircraft negated the dual-runway system by reducing its capacity to that of a single approach lane.

Finally it was decided to stagger the turn-on altitudes as shown in Figure 2, using 1000 feet of vertical separa­tion between aircraft feeding into the opposite lanes, and maintaining this separation until the aircraft were estab­lished on their final approach courses. If an aircraft over­shot the initial turn, it could get back on course before it became a hazard to traffic in the opposite lane. At the expense of a somewhat longer final approach course, this procedure solved the hazardous turn-on problem, and permitted completely independent operation of the two traffic lanes.

After these simulation tests were completed, little was done on this subject for several years, as no U.S. airport was yet equipped, or required, to begin dual-approach

opei-otions. Finally, in 1957, the Airways Modernization Board began a ver·y sophisticated mathematical study to determine the minimum safe separation which should be used between para llel ILS courses for dual approach ope-

22

rations. Two years and several thousand dollars later, the decision was approved, that under the assumptions used in the study, 5000 feet appeared to be a sufficiently safe standard. Signiflcanlly, this figure was only 280 feet less than the initial spacing figure which had been pulled un­scientifically oul of a hat, for the 1952 simulation tests.

Dual-Approach Operations at Chicago

Meanwhile, in October, 1958, the first flight tests of the procedures developed in the 1952 simulation tests were conducted by FAA and airline pilots at Chicago O'Hare Airport. These tests, which were conducted in VFR condi ­tions, duplicated exactly the results obtained from the

simu.lati.on runs. The airline pilots were unexpectedly en­thus1ast1c about the procedures, and some even said they would be w1ll1ng to operate with only 500-foot vertical

separation at the turn -on point. In lieu of this idea, which would have reduced the length of the final approach paths slightly, the turn -on separation was kept at 1000 feet, but the two glide paths were set at 2'/2 degrees and 3 degrees. respectively. With O 'Hare's staggered runway configuration, the d1ffere.nce in glide path angles pro­duced add1t1onal separation between the flight paths all the way to touchdown, as shown in Figure 3.

This installation, monitored by a special ATC radar setup, was thoroughly tested in VFR operations. Authori­zation was finally granted for parallel IFR approach ope­rations down to 900 feet ceiling and 3 miles v isibi l ity. After more experience was gained, these minima were lowered to 500 and 11/ 2; they are presently set at 400 and 1, a standard which still virtually precludes the occurrence of missed approaches. However, diverging missed ap­proach paths for the two runways are available if needed.

O'Hare's traffic usually consists of a series of inbound and outbound peaks or waves. When arrival traffic slacks off, the excess capacity of the dual runway configuration is used to advantage in expediting departures.

The dual approach system handles the largest arrival peaks presently encountered (about 60 arrivals per hour) with a minimum of delay. Because O'Hare has other in­dependent runways available for take-off, it is not usua l ly necessary to slow down the arrival rate in order to accom­modate departures.

Parallel approach operations are conducted by two controller teams, one for each runway. Each team con­sists of a hand-off man who accepts arrival data from the Air Traffic Control Center, and identifies the radar target; a radar contro !ler who sequences, descends, spaces, and guides each aircraft from the hand-off point to the final approach course; and a final approach radar monitor who normally doesn't say much, but who carefully watches the progress of each aircraft target coming down the final chute.

Except for unusual circumstances, each traffic lane operates independently of the other. Radar vector pat­terns include a short period of level flight at the loca lizer interception altitude, so that aircraft can lose any excess speed, before turning on the final approach course. To minimize overshoots, the final vector heading, prior to interception of the localizer course, seldom exceeds 20 degrees from the final approach heading.

Two final approach monitor controllers (one for each approach lane) share the responsibility for ma inta ining proper separation between a ircraft on the final approach course. Each mon itor controller uses the localizer voice frequency o f his respective ILS, to communicate any neces­sary instructions to pilots. Pilots remain on their previ­ously assigned approach contro l transmission freque ncy, to acknowledge any instructions.

The monitor controllers sha re a single ASR-4 (ai rport surveillance) radar indicator, w hich displays an expanded l 0-m ile-range-scale presentation, decentered so as to show the entire final approach area from turn-on to touch­

down. Each monitor controller is responsible for keep ing his aircraft w ithin 1500 feet of the localizer course a l l the way down the final approach course.

The 1500-foot safety zones are marked on th e scope by video mapping. The paralle l localizers at O 'Hare are 6510 feet apart ; between the tw o 1500-foot safety zones is a buffer area, or no-transgression zone, wh ich is shown in Figure 4. Th is zone is 3510 feet w ide. Shou ld an a ircraft from one lane get into the no-transgression zone (in spite of all efforts of the monitor controller) it is ma ndatory that the other monitor contro l ler take immediate d iver­sionary action with any of his aircraft which happen to be within three mi les of the infringing aircraft.

At present, each mon itor controller also has a PAR (precision approach radar) scope. However, PAR is con­sidered on ly a supplemental too l, and probably w i l l not be deemed mandatory for any fu ture dual-runway instal­lations.

Some co ntrollers would l ike to see future dual­approach operations monitored on a specially-desig ned fast-scan survei llance radar, wh ich would cover a 60'· azi­muth sector to a rang e of about 16 miles, with a narrow beam hav ing very high az imuth resolutio n. Pref erably the proposed radar w o uld al so have alternate covera ge in the reverse d irection , to monitor dual bock-course approa­ches.

/ /

0 0 •()

0 0 lf)

N

Figure 2 Staggered -Altitude Tu rn-On Proced ure deve loped in 1952 Simula tion Tri al s

23

Figure 3 Stogge ced-Altitude Turn-On Procedure presently used at O'Hore Airport

Drawing not to scale

--+ 14L

1500' Safety Zone

--+-~ 1500' Safety Zone

14R

Figure 4 Sof•dy -Zon {: Co n ~~ pt fh t: sentl y used at O 'Hcire A irport

24

I say, Humphrey, look at that simply marvellous

aeroplane. How madly fast it's flying.

And there's another one over there - and there - and there

Do you suppose they know where they're going?

Crazy man. of course there's a frantic genius in that control tower place taking care of all that

Like poor Cuthbert, my controller cousin,

who was wafted screaming to a clinic?

You'd think there was an easier way . . .

. .. There is!

The precise push-button

navigation system with

air traffic control data link

Restriction of VFR-Flights on Dutch Airways

On 31st March 1964 the Netherland's Department of Civil Aviation issued the following NOT AM:

20/64

By joint Decree of 6th January 1964 of the Director­General of Civil Aviation, the Chief of Staff of the Royal Netherlands Airforce and the Chief of Staff of the Royal Netherlands Navy, based on Article 5, paragraph 3 of the Netherlands Air Traffic Regulations the following has been !aid down:

Article l

During the hours of daylight flights in Control Areas must be carried out in accordance with IFR irrespective

of weather conditions .

Article 2

Article 1 is not applicable to:

a) flight with civil aircraft:

1. which are carried out in Amsterdam TMA and Eelde TMA ;

2. which cross airways outs ide Amsterdam- and Eelde TMA, provided that visua I reference to the grourc! is maintained and a crossing-clearance has been

obtained from ATC.

b) flights with military aircraft in as much as these flights are not perform ed along airways or along predeter­mined routes in th e upper-a i rspa ce.

c) flights along airway Blue 29 or flights crossing this airway ond flights along predetermined route Blue 29.

Article 3

Clearances mentioned in Art icle 2 under a) 2 will be granted on!y when two-way radio communication with ACC or FIC Amste1·dam can be maintained.

The clearances as mentioned above have to be re­quested from ACC or FIC Amsterdam on the appropriate radio frequencies a t least ten minutes before the time of cross ing. When granting such o c lea ran ce ACC will ensure sepa ration between cross ing traffi c and I FR-traffic in air­ways.

Requests shall be made as follows:

(aircraft identification) request VFR-cross-ing clearance a irway .. at .. ... ... (time and point of cross ing - See note) flight leve l ...... . . groundspeed ....... . kts fro ck . .. .. .

Note: Crossing-points should preferably be given in terms of direction and distance in nautical miles in rela­tion to compulsory report ing points for IFR flights 1n the airway concerned.

26

Cross ing-po ints may a lso be indicated in rela tion to a suffi c iently impo r tant geographical pos ition.

Crossings shall be made at right angles to the cen­tre l ine of the airway in question.

Attent:on is drawn to the fact that the existing possibi­lities of carrying out flights in VMC below airways al alti­tudes below 900 metres (3000 feet) without ATC-clearance remain unaffected.

Dote of coming into force of this Regula t ion 15th April 1964.

* The publication of this NOT AM is a major step towards

positive control, and on attempt to exclude the "see and be seen p rinciple" from a controlled environment.

Executive Secretary Geoffrey Monk discussed the sub­ject with Captain C. C. Jackson, IFALPA. It goes without saying that those who fly IFR, i.e. the airline p i lots, ore all in favour of the new regu lation.

But how about the VFR-Operators?

Their share has been du ly considered. For the Depart­ment of Civil Aviation have also published the following NOT AM:

24/ 64 Amsterdam FIR. Lower Limit of Airways raised With effect from 7th M oy, 1964, 0001 GMT the lower limit of the Airways in Amsterdam FIR w ill be raised from 900 m (3000 ft) MER to 1200 m (4000 ft) MER with exception of those ports of the airw ays Blue ] and Red 1 West of Spi jkerboor VOR/NDB.

By raising the lower limit of the airways to 4000 ft, the 1-.Jetherlonds Authori ties have established suff icient air­space for General Aviation lo operate with the least restriction possible. Th is w as confirmed by Capta in Koe­mans, International Council of Aircraft Owner's and Pilot's Associations, in an initial statement communicated to the Editor. We shall receive further word from ICAOPA soon.

And what do th e Cont rollers think about the VFR­;estriction ?

Will van Blokland, Secretary of the Netheriand 's Guild of Air Traffic Controllers, to ld us that under the new system things run smoothly, and moior problems have not yet occured. EH

5. Convention of UK Guild of Air Traffic Control Officers

On 6.-8. October 1964 the UK Guild of ATCOs will ho ld its 5th Convention in Bournemouth. The Theme w ill be " O verseas Ai r Routes " and the main subjects will be "The N o rth Atlant ic Routes ", and the " Low Leve l Cross Channel (English Chonnelj Routes " . Papers wi l l be read by the M inistry of Aviation, the Royal Aircraft Establish­ment Pilots of BOAC, BUA, and Pon American Airways and b y the Guild.

There w ill be on exhibit ion from Industry and various 01·ganisations. GWM

The International Federation

of Air Traffic Controllers Associations

Addresses and Officers

AUSTRIA

Austrian Air Traffic Controllers Association Vienna Airport Austria

Chairman Secretary

BELGIUM

H. Brandstetter H. Kihr

Belgian Guild of Air Traffic Controllers Airport Brussels Nation a I Zaventem 1 Brussels

President Vice-President Secretary Treasurer Director Director Director Director Editor

CANADA

A. Maziers R. Sadet R. Tamignieaux R. Maitre M . de Craecker M. Courtoy J. Lacour! Y. Viroux 0 . Haesevoets

Canadian Air Traffic Control Association P. 0. Box 241 Malton, Ontario Canada

President Vice President Managing Director

CENTRAL AFRICA

J. R. Campbell W . B. Clery L. R. Mattern

Association of Air Traffic Control Officers Private Bag 2 Salisbury Airport Southern Rhodesia

Secretary L. J. Cotsell

DENMARK

Danish A ir Traffic Controllers Association Copenhagen Ai1·port - Kastrup Denmark

Chairman Director Deputy

FINLAND

Henning Throne A.G. T. Nielsen H. D. Christensen

Association of Finnish Air Traffic Control Officers Suomen Lennonjohtajien Yhdistys r.y .

Air Traffic Control Helsinki Lento Finland

Chairman Vice-Chairman Secretary Member Member

FRANCE

Fred. Lehto Jussi Saini Voino Pitkanen Heikki Riitaho E. Kurvinen

French Air Traffic Control Association Association Professionnelle de la Circulation Aerienne B. P. 21 Aeroport du Bourget Seine France

Director

GERMANY

Maurice Cerf

German Air Traffic Controllers Association verband Deutscher Flugleiter e.V. Cologne-Bonn Airport Porz-Wahn Germany

Chairman Vice-Chairman Vice-Chairman Secretary Treasurer Editor

GREECE

H.W.Thau W . Fuhrer H. W. Kremer F. Werthmann H. Prell J. Gertz

Air Traffic Controllers Association of Greece Air Traffic Control Athens Airport Greece

President Secretary

I CELANO

Nicolaos Gonos P. Mathioudakis

Air Traffic Control Association of Iceland Reykjavik Airport Iceland

Chairman Secretary

IRELAND

Valdimm Olafson Kristinn Sigurdsson

l1· ish Air Traff ic Contrnl Officers Association Air Traffic Confrol Centre Shannon Ai1·port l1·eland

27

President Vice-President Secretary Treasurer

IS RAEL

D. J. Eglinton P. J. O'Herbihy J.E. Murphy P. P. Linehan

Air Traffic Controllers Association of Israel P. 0. 8. 33 Lod Airport Israel

Chairman Jacob Wachtel

ITALY

Associazione Nazionale Assistenti Civili Navigazione Aerea Italia Rome Airport, Italy

Chairman Secretary

LUXEMBOURG

C. Tuzzi L. Belluci

Luxembourg Guild of Air Traffic Controllers Luxembourg Airport

President Secretary Treasurer

NETHERLANDS

Alfred Feltes Andre Klein J.P. Kimmes

Netherlands Guild of Air Traffic Controllers Willem Molengraafstraat 22 Amsterda m-Slootermeer

President Secretary Treasurer Member Member

NORWAY

Lufttraflkkledelsens Forening Sola Airport Stavanger Norway

L. N. Tekstra W. G. van Blokland J.C. Bruggeman J. L. Evenhuis H. A. C. Hauer

Chairman Vice-Chairman Secretary Treasurer Officer Director Deputy

SWEDEN

Jon Stangeland Knut Christiansen Arne Gravdal Seren Norheim Arne Helvik Ottar Saebo Arne Gravdal

Swedish Air Traffic Controllers Association Air Traffic Control Bulltofta Airport Malmo 10 Sweden

Chairman Secretary

SWITZERLAND

Carl Ahlborn Lennart Jogby

Swiss Air Traffic Controllers Association V. P.R. S. Air Traffic Control Zurich-Kloten Airport Switzerland

Chairman

UNITED KINGDOM

Bernhard Ruthy

Guild of Air Traffic Control Officers 14, South Street Park Lane London W 1

Master Clerk Executive Secretory Treasurer Director

URUGUAY

J. N. Toseland L. S. Vass G. Monk E. Bradshan A. Field

Asociation de Control adores de T ransito Aereo del Uruguay Potosi 1882 Montevideo, Uruguay

Chairman Secretary

A. R. Tard6guila J.E. Bianchi

Welcome to IFATCA

We are pleased to announce the affiliation of the following new Members:

28

Canadian Air Traffic Controllers Association, Associazione Nazionale Assistenti Civili Navigazione Aerea Italia Asociation de Controladores de Transito Aereo del Uruguay. '

At the same time we take great pleasure to report that

SELENIA lndustrie Elettroniche Associate S.p.A., Rome, Italy

have joined IFATCA as Corporation Member.

Corporation Members

of the International Federation

of Air T raffle Controllers' Associations

Cessor Radar and Electronics Limited,

Harlow, England

The Decca Navigator Company Limited,

London

ELLIOT Bros. Ltd., London

Hazeltine Corporation, Little Neck, N. Y., USA

IBM World Trade Europe Corporation,

Paris, France

KLM Royc:il Dutch Airlines

The Hague, Netherlands

Marconi's Wireless Telegraph Company, Ltd.

Radar Division

Chelmsford, Essex, England

N.V. Hollandse Signaalapparaten

Hengelo, Netherlands

Selenia - lndustrie Elettroniche Associate S. p. A.

Rome, Italy

Telefunken AG, Ulm/Donau, Germany

Texas Instruments Inc., Dallas 22, Texas, USA

The International Federation of Air Traffic Controllers' Associations would like to invite all corpora­tions, organizations, and institutions interested in and concerned with the maintenance and promo­tion of safety in air traffic to join their organization as Corporation Members.

Corporation Members support the aims of the Federation by means of an annual subscription and by supplying the Federation with technical information. 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 fraffic control.

For further information on Corporation Membership please contact Mr. H. W. Thau, Secretary, IFATCA, Cologne-Wahn Airport, Germany.

'-------------------------··--------------------------------·

JET AGE TRAFFIC CONTROL

Selenia Air Traffic Control L-band Radar for

terminal areas and air route control

Gap-free and clutter-free coverage D Virtual elimination of blind speed ~1 Low and high data rate availability o Frequency diversity operation u Extra high-angle antenna coverage for in-close targets ci MTI system with double delay line canceller and triple staggered repetition r3te o High Transmitter power Low noise Parametric Amplifier

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~k --=--:mc:r-t• 41& INDUSTRIE ELETTRONICHE ASSOCIATE S.p.A.

~----P.O. BOX 7083 - ROME CITALYJ