Automation and Systems Issues in Air Traffic Control

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~ Series F: Computer and Systems Sciences Vol. 73

Automation and Systems Issues in Air Traffic Control

Edited by

John A. Wise Center for Aviation/Aerospace Research Embry-Riddle Aeronautical University Daytona Beach, FL 32114-3900, USA

v. David Hopkin RAF Institute of Aviation Medicine Farnborough, Hampshire GU14 6SZ, United Kingdom

Marvin L. Smith Airway Science Simulation Laboratory Embry-Riddle Aeronautical University Daytona Beach, FL 32114-3900, USA

Springer-Verlag Berlin Heidelberg New York London Paris Tokyo Hong Kong Barcelona Budapest Published in cooperation with NATO Scientific Affairs Division

Proceedings of the NATO Advanced Study Institute on Automation and Systems Issues in Air Traffic Control, held in Acquafredda di Maratea, Italy, June 18-29, 1990.

ISBN-13: 978-3-642-76558-2 e-ISBN-13: 978-3-642-76556-8 001: 10.1007/978-3-642-76556-8

This work is subject to copyright. All rights are reserved, whetherthe whole or part of the material is concerned, specifically the rights oftranslation, reprinting, re-use of illustrations. recitation, broadcasting, reproduction on microfilms or in other ways, and storage in data banks. Duplication of this publication or parts thereof is only permitted under the provisions of the German Copyright Law of September 9, 1965, in its current version, 1985. and a copyright fee must always be paid. Violations fall under the prosecution act of the German Copyright Law

© Springer-Verlag Berlin Heidelberg 1991 Softcover reprint of the hardcover 1st edition 1991

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Preface

In recent years, increases in the amount and changes in the distribution of air traffic have been very dramatic, and are continuing. The need for changes in the current air traffic systems is equally clear. For example, the impact of air traffic systems on the economic well-being of a country can be demonstrated by the fact that, in the United States alone, delays due to air traf­fic problems were responsible for an estimated loss of over five billion dollars in 1988 (for excess fuel, time losses, etc.). Losses of over ten billion dollars per year are expected by 1998 if dramatic changes are not made. As a result, members of the NATO Alliance are all in vari­ous stages of modernizing and automating their air traffic control systems.

While automation is generally accepted as a method of improving system safety and per­formance, one of the conclusions of the 1986 NATO Advanced Research Workshop on information system failure (Wise and Debons, 1987) was that high levels of automation in complex human-machine systems can have a negative effect on total system performance and have been identified as contributing factors in many accidents and failures. Examples of this effect can be found in the operation of most complex systems such as aircraft and nuclear power plants. As a result, there is a growing body of theoretical and systems knowledge that attempts both to explain these events and to provide guidance on how to avoid similar prob­lems in new systems. For example, at the 1989 International Symposium on Aviation Psychology, several researchers identified critical issues and problems associated with the proposed increases in automation in air traffic control systems throughout the NATO countries. Morrison and Rosenthal, in separate papers, identified communications and human information processing loads as highly correlated with air traffic control system errors. Woods, in a counterpoint, presented a wide range of current examples where automation introduced to address those problems actually generated an entirely new set.

In addition, significant advances have been made in understanding the different types of cognitive errors that people make in complex, time-constrained, real-world decision making that is typical of air traffic control. This knowledge is critical not only to the design of the system hardware and software, but equally to the selection and training of operators. Like­wise, the understanding of the impact of of automation-induced stress on system effectiveness has also advanced to the stage where it can assist in the analysis of failures and the design of more effective systems.

Those responsible for designing the advanced air traffic control systems to be implemented throughout the Alliance during the next decade need to be aware of recent progress concerning the most effective application of automation and artificial intelligence in human-computer systems. This need is critical. Design decisions made in the next few years will affect the safety and vitality of air transport in and between the nations of the Alliance. The application of the above information to those decisions will result in safer, much more efficient air transportation.

Acknowledgements

The editors would like to acknowledge the work of those individuals whose untiring effort and dedication to the Advanced Study Institute made possible the publication of these proceedings. In a certain sense, each of them should have his or her name on the cover, be­cause without anyone of them, this volume would not exist.

For the success of the Institute, we must thank a large number of people and organiza­tions. First, we must thank our sponsors, without whom the Institute could not have taken place. These included:

• NATO Scientific Affairs Division • U. S. Federal Aviation Administration • Embry-Riddle Aeronautical University • Research Institute for Information Science and Engineering

We also must thank the U. S. National Science Foundation which supplied financial support for several participants, and Transport Canada which assisted the Institute in every way it could.

We must thank the Institute's staff who worked hard before, during and after the meeting, particularly Barbara Gibson, whose administrative skills impressed everyone (and without whom, chaos could have easily broken out). We want to thank Jan Goodrich, whose skill with the written word helped everyone produce a paper to meet the goal of high information transfer. We also want to thank Kevin Norris for his outstanding work in recording the Institute, and Mr. Peter McAlindon for his technical and administrative support.

All of the participants owe a debt of gratitude to the staff at the Hotel Villa del Mare, who provided the ideal environment for exchange of current ideas and the generation of many new ones.

We also must thank a great number of people who assisted in a variety of ways to get the papers into the final electronic form that allowed their publication. At Embry-Riddle Aero­nautical University, they include: Sandy Oliver, Mike Graves, Joan Sullivan, Tammy Clem, Kevin Minton, Carol Liptak, and Laura Hammond, Brian Pape. At the RAF Institute of Aviation Medicine, they include: Natalie Mitchell, Margaret Fawcett, and Jon Coldwell.

While our names are on the cover, we respectfully share whatever credit arises from this volume with all of the above.

John A. Wise V. David Hopkin Marvin L. Smith

Table of Contents

Editors' Summary ....................................................... xiii

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

The Impact of Automation on Air Traffic Control Systems. . . . . . . . . . . . . . . . . . . . . . . . . .. 3 V. David Hopkin

Assumptions and Automation in Air Traffic Systems ............................... 21 John A. Wise

Perspectives on Air Traffic Control Automation . ............................... 29

Computerization and Automation: Upgrading the American Air Traffic Control System ... 31 Arthur A. Simolunas and Howard S. Bashinski

The Canadian Automated Air Traffic System (CAATS): An Overview ................. 39 Paul Stager

The Implementation and Impact of Automatic Data Processing on UK Military ATC Operations ............................................... 47

S. E. J. Lane

From Under the Headset: The Role of the Air Traffic Controllers' Professional Association in Present and Future Air Traffic Control Systems Development. ........... 55

John Levesley

A Collation of Approaches to Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 61

Air Traffic Control and Systems Issues .......................................... 63 Anthony Debons

ICAO and Future Air Navigation Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 79 John N. Bradbury

Social, Political, and Regulatory Issues Concerning Harmonization of Interacting Air Traffic Control Systems in Western Europe ......................... 101

Randahl N. Lindgren

Aircraft Traffic Forecast and Communications Requirements in the Year 2000. . . . . . . .. 107 PeterJ. McAlindon

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Automation in Environmental Engineering ...................................... 121 Nefdet Alpaslan

The Role of Automation and Control Systems in Water Resources Engineering ......... 127 Nilgun Harmancioglu

Automated Aids and Their Evaluation . ...................................... 135

Intelligent Dialogue in Air Traffic Control Systems ............................... 137 Jack L. Edwards

Close Ground/Air Cooperation in Dynamic Air Traffic Management. ................ 153 Andre Benoft

Multi-layer Queuing Model to Check Automated Air Traffic Control Systems .......... 161 J. C. Sargis andA. V. Sebald

Application of Planning Aids for Air Traffic Control: Design Principles, Solutions, Results. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 169

Uwe Volckers

Artificial Intelligence and Human Factors in ATC: Current Activity at Eurocontrol Experimental Centre .............................. 173

Hugh David

Meeting the ATC Challenge through Simulation ................................. 181 W. K. Sandiford

Human Attributes, Representatives, and Requirements . ........................ 185 in Relation to Automation

The Aims of Human Factors and Their Application to Issues in Automation and Air Traffic Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 187

P. A. Hancock

Human Factors in System Design. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 201 PaulO. Day

Automated Systems: The Human Factor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 209 Daniel J. Garland

Modelling Control Tasks in Complex Systems ......................... : ......... 217 Morten Lind

Mental Models in Air Traffic Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 235 Richard H. Mogford

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The Controller in Human Engineering. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 243 Michael Tonner

Acceptance of New Systems by Air Traffic Controllers ............................ 249 Egbert Seidel

Effects of the System on the Human: Stress and Workload ...................... 253

Stress and Workload Management in Air Traffic Control. .......................... 255 AndrewJ. Tattersal~ Eric W. Fanner, andAndrewJ. Belyavin

Shiftwork and Circadian Variations of Vigilance and Performance ................... 267 Giovanni Costa

Operator Workload as a Limiting Factor in Complex Systems ....................... 281 P. G. A. M. Jorna

Attention, Workload, and Automation .......................................... 293 Barry P. Goettl

Approaches to Error and Failure. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 299

ICAO and Civil/Military Coordination ......................................... 301 JohnN. Bradbury

Error Models for Operating Irregularities: Implications for Automation ............... 321 Paul Stager

Cognitive Failures in Military Air Traffic Control. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 339 Jacob Empson

Human Factors in ATC Communication ........................................ 349 Ioannis Fokas

Results of a Perceptual Study on Human Error in Computer Systems Based on Bailey's Research. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 353

Esther E. Horne, Jo Lee Pierce and Douglas A. White

Organizational and Cultural Aspects of Air Traffic Control Automation. . . . . . . . .. 365

Automation, Information, and Consciousness in Air Traffic Control. ................. 367 Ron Westrum

Issues in Cultural Ergonomics ................................................ 381 Michael Kaplan

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Air Traffic Controller Working Conditions and Organization: Suggestions for Analysis and Improvements from a Psychological Point of View. . . . . . . . . . . . . . . .. 395

Claudia Harss, Jitzchack Lichtenfeld, Michael Kastner, andJan Goodrich

Automation as an Influence on Controller Selection . ........................... 407

Selecting for Air Traffic Control: The State of the Art. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409 Hilda Wing

Selection of Air Traffic Controllers for Automated Systems: Applications from Today's Research ........................................... 429

Pamela Della Rocco, Carol A. Manning, and Hilda Wing

Automation Issues for the Selection of Controllers ................................ 453 Gill Nyfield

Automation in ATC: How Does It Mfect the Selection of Controllers? ............... 461 Hinnerk Eif3feldt

Consequences of Automation for Training and Resource Management . ........... 467

Training Requirements for Automated ATe. ................ '" ................. 469 Rod Baldwin

Adaptive Training to Accommodate Automation in the Air Traffic Control System ...... 481 Marvin L. Smith

Resource Management Training for Air Traffic Controllers ......................... 497 Daniel A. Herschler

Non-Technical Training for Technocrats: Resource Management at Canadian Airlines ... 505 Nicole Svatek

Critical Issues for Decision Makers in Providing Operator and Maintainer Training for Advanced Air Traffic Control Systems ............................... 513

RichardB. ChobotandMary C. Chobot

Speculations on Automation and Air Traffic Control . .......................... 527

A Modest Proposal for Future Systems ......................................... 529 JohnA. Wise

The Blue Sky Challenge: A Personal View ...................................... 535 John Levesley

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Automation and Systems Issues in Air Traffic Control: Blue Sky Concepts ............ 541 V. David Hopkin

What If ... We Integrated Both Training and Monitoring Functions into Air Traffic Control Workstations? ........................................ 547

Marvin L. Smith

Some Final Thoughts . .................................................... 551

Closing Remarks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 553 V. David Hopkin

Anyone at Home? ........................................................ 561 Hugh David

Participants. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 563

Photographs of Air Traffic Control Facilities. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 571

Index and Glossary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 585

Editors'Summary

Introduction

The ASI, as most meetings of this type, raised more questions than it answered. For example, it was agreed that we need to identify the types of errors that are predetermined by the design process. While there is a tendency to see problems as system-driven, most discussions were about things that are human-driven. And while there was a feeling that design is biased toward technical factors, most discussions were about human factors.

We talked about the adaptability and flexibility of software. Adaptability and flexibility are emotive words that sound great. But at some point they change into instability and unpredictability. Where?

We discussed what should be taught in air traffic programs besides knowledge and procedures. What other kinds of attributes should be taught? We also mentioned the teachability of automation. One may have to determine not just that an automated aid can be made to function, but also whether it can be taught. Should we be selecting forms of automation based on their teachability?

We need further to address performance measures. Have we been measuring the right things? Are there things, like understanding or memory, which may be more important than costs, that we don't measure? We need tools to measure the effects of automation.

We addressed the concept of over-control, which implies an optimum level of sharing responsibilities between ground and air personnel within the air traffic control process. It is not necessarily all one or the other, but an optimum level is somewhere between. How do we recognize that we have it?

One criticism of the ASI would be that we concentrated too extensively on controllers and technology. We did not devote much time to the needs and contributions of the managers, instructors, engineers, maintainers, pilots, and passengers. They will all be affected by automation, some more than controllers. For example, there is a marginal, but definite, advantage to the air traffic control system to bring large aircraft in as a batch. But as a result, hundreds of people will be waiting at immigration and the baggage hall, trying to get through customs, and trying to get onto ground transport all at the same time. We need techniques and tools for comparing air traffic control advantages with the sort of chaos that might be resulting in other parts of the air transportation system.

Topics Addressed

Automation's Impact

A brief description and explanation of the structure of this text may help the reader to gauge the range of its contents and locate papers of particular interest. The Keynote Paper adopts a historical perspective to review previous forms of automation in air traffic control, some of the advantages and difficulties in applying them, and the future consequences of automation

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for air traffic control in the context that the envisaged future traffic-demands make the provision of more automation inescapable. Therefore, the debate is on the forms automation should take and the timescales for it, rather than on whether there should be further automation. Wise asks that the readers reassess their assumptions about both automation and air traffic. He attempts to assist the readers by providing a number of antitheses to commonly held assumptions.

Current Perspectives

The first section contains four papers which consider perspectives on the impact of automation on air traffic control, generally by relating envisaged future developments to current practices. The first paper, by Simolunas and Bashinski, describes the largest and perhaps most ambitious envisaged application of computerization and automation to air traffic control, in the example of the American Advanced Automation System, by indicating some of the underlying procedures adopted and the reasons for them; by describing the ways in which the user has been involved in the system evolution process; and by indicating some of the problems that have been envisaged and allowed for. The paper by Stager in this section, noting that Canada is marking fifty years of air traffic control, describes Canadian plans for replacing existing air traffic control systems, the intended uses of automation in the evolved replacements, and the rationale behind the project. The paper by Lane is a reminder that air traffic control must cover both military and civil requirements; it describes how military and civil air traffic control needs are coordinated in the United Kingdom, and suggests how future automation will affect military air traffic control with reference to data processing. Levesley's paper, giving the air traffic controller's point-of-view, indicates ways in which controller opinion is coordinated internationally and represented nationally in the planning and evaluation processes, to confirm that proposed forms of automation will be operationally satisfactory and acceptable.

Systems Issues

The section on systems issues begins with a paper by Debons, which provides a review of the kinds of thinking applied when systems issues are discussed, of the relevance of these to air traffic control, and of assumptions which underlie the impetus to extend automation in air traffic control. The remaining papers in this section exemplify the breadth of issues covered when automation in systems is considered. Bradbury's paper is a timely reminder that air traffic control is international, and that the sensed data, the equipment, and the procedures and policies of automation in air traffic control in the future have to be the subject of international coordination and agreement; agreement is perhaps particularly essential in relation to navigation and the ways in which more technically advanced and more automated navigation aids may be employed. The paper by Lindgren focuses on the harmonization problems of Western Europe, where differences in national practices, often confined to quite small geographical areas, have to be reconciled; common practices have to be developed and proved which are politically acceptable, can be translated into common regulatory practices, and will accommodate future changes, including increased air traffic and closer integration with Eastern Europe. The paper by McAiindon is a reminder that the effects of automation on air traffic control have to be predicted well in advance; both their nature and the timing of the

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need for them depend not only on technological advances but on forecasts of future traffic demands and resultant communications requirements many years ahead; these forecasts also must be linked to the mechanisms for international agreements and standardization.

The papers by Alpaslan and Harmancioglu draw parallels between water resources, engineering and air traffic. control, demonstrating that automation being considered for application in both systems has a great deal in common, even though the purposes and products of the systems seem initially very different. These papers were a timely reminder that, in considering the impact of automation in relation to air traffic control, much can be learned by looking at its impact in other fields of application, in terms of both the problems likely to arise and the kinds of solutions that may be practical.

AutomatedAids and Their Evaluation

This section considers some ways in which automated aids, particularly those related to artificial intelligence, are being considered or applied now in relation to air traffic control problems in various countries; it also looks at the facilities available for discussing and evaluating such issues by various forms of simulation. The very rapid and continuing developments in artificial intelligence raise the issue of how air traffic control might benefit from these advances. Edwards approaches this issue by cOnsidering the interactions between the controller and the system as a dialogue; he suggests that, while much existing functionality may be automated, and many of the traditional functions of the air traffic controller (particularly in en-route air traffic control) can be automated in the future, the issue arises of not just whether they can be but whether they should be. The paper by Benoit describes some of the work conducted by Eurocontrol to provide automated aids to the controller, in order to improve the efficiency of the on-line management of air traffic control; the emphasis is on evolving efficient means of controlling traffic within many of the existing constraints. Benoit also describes a new planning system for greater efficiency in controlling approaching aircraft, in order to increase the traffic handling capacity, improve the service offered, and not incur penalties in terms of excessive workload; this paper describes the expected benefits from a practical form of automated assistance for air traffic control, not in the distant future but being evaluated now. Sargis discusses the potential use of a multi-layer queuing model as an aid to check ATC system effectiveness; the logic -ased problem-solving approach discussed would allow an ATC system to learn and adapt to environmentally in­duced changes. The paper by David describes some of the practical steps being taken to integrate within Eurocontrol the approach to evaluations intended to answer both general and specific questions, dealing with particular airspaces chosen as exemplars; evaluations are being used both to furnish answers to practical issues and to tryout and prove various measurement techniques and methods. The paper by Sandiford is based on the work of the Air Traffic Control Evaluation Unit in the United Kingdom, and pays particular emphasis to the relationships between real-time and fast-time studies and to the role of simulation in relation to valid findings which will extrapolate to real-life environments.

Human Attributes and Automation

The impact of automation on air traffic control from a variety of perspectives, ranging from the theoretical to the applied and from the general to the particular, is addressed in this section. Numerous perspectives are brought to bear on the central issue of the reconciliation of human characteristics and attributes with progressive automation and technological

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advances, in the furtherance of safe and efficient air traffic control. Hancock's paper takes a fresh look at the fundamental aims of human factors in the context of complex systems, bringing many theoretical constructs to bear to further an understanding of the relationships involved and how progress may be made on reconciling human and machine. Day, who also addresses the role of human factors as a discipline, advocates that human factors should return to its earliest roots through specialist involvement in the system-design cycle; he notes that those who commission air traffic control systems might learn from military experience about the procurement cycles and the integration of the user's point-of-view during various stages of system procurement. Garland makes more explicit a widespread implicit view, present throughout many of the deliberations of this ASI, questioning whether the availability of automation is a sufficient reason for introducing it; he advocates an approach which has a better philosophical base for what automation seeks to achieve and a more human-centered approach, to avoid the most adverse human factors consequences of automated systems and provide a better-planned progressive introduction of automated aids in step with user needs. Lind considers the various means of modelling the control task in complex systems, indicates that air traffic control is (in this sense, an example of broader kinds of systems, in that the modelling methods developed for them are applicable to it), and shows how models can not only describe the complex interacting dynamics of systems but also account for the end products of systems. Mogford also addresses the issues of modelling but from the viewpoint of mental models; he outlines their salient characteristics, how they can be applied to air traffic control, and how they may promote insight into various aspects of the controller's thinking and information processing. Tonner's paper lists, from the point of view of the air traffic controller, themes relevant to the application of automation in air traffic control which seem currently insufficiently recognized or unanswered, as well as the controller's view of essential requirements for successful air traffic control which did not seem to be recognized sufficiently elsewhere. Tonner emphasizes a theme which recurred often throughout the ASI: the need for everyone to pool their expertise and work with a common purpose, since ultimately all the work has the common purpose of ensuring safe and efficient air traffic control. Seidel notes, as do others, that controllers generally find air traffic control intrinsically satisfying; he also reviews European developments in the automated provision and manipulation of data in relation to air traffic control as it is - and as it is expected to become - with particular reference to controller acceptability of proposals.

Stress and Workload

The next section deals with some aspects of the impact of the air traffic control system on the human being, with particular reference to stress and workload and the changes that may be wrought by increased automation. A paper by Tattersall provides an overview of methods to assess the controller's ability to manage work demands, with emphasis on the effects of failure to manage the demands sufficiently and on the measures for identifying when this has occurred, he reviews the various kinds of responses to stress, mechanisms for workload regulation, and a recent extensive survey of factors relevant to stress and workload in air traffic control. Costa's paper focuses primarily on the effects of shiftwork and circadian rhythms on human performance, and on the consequences of such work for the human being in terms of medical indices, performance indices, and subjective assessments, drawing on both literature and survey data. Jorna, in considering workload problems of air traffic control, employs the concept of mental workload to help to explain some of the more unexpected

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human consequences of the introduction of more automation; he brings out the complexities of "workload" revealed both by the very high 'number of factors to which it appears to be related and by the fact that the relationships do not always accord with what would be expected. Goettl discusses the different kinds of automation that can be applied to air traffic control and some of the consequent human factors issues, particularly those related to task performance.

Error and Failure

This section of papers addresses issues related to human error or failure. Bradbury traces the connection between particular failures and the emergence and agreement of international regulations and practices, and discusses methods of disseminating literature to promote safety and minimize failure; sources of potential confusion, such as insufficient familiarity or discrepancies between military and civil practices or liaison, are identified in terms of their implications for the future safety of air traffic control. Fokas notes that an automated air traffic control system has to handle a mixture of old and new procedures; he reviews typical kinds of human error within air traffic control systems, particularly those related to communication, as a means of recognizing and minimizing such errors. Stager considers various kinds of models of human errors, and various error taxonomies, in relation to both the kinds of error which typically occur within air traffic control systems, and to the impact of automation on the nature of the errors that can be expected; from this point of view, he considers what the most appropriate levels of automated air traffic control operations might be. Empson, in looking at cognitive failures in air traffic control, provides a classification of failures and specific examples of the occurrence of various identified error-types within air traffic control communications or procedures; he considers the implications not only for automation but also for selection and workspace design. Home uses Bailey's classification of seven broad categories of human error in systems to speculate on how they could be applied in air traffic control to resolve human-error problems.

Organizational and Cultural Issues

The papers in this section address aspects of automation in air traffic control related to its organizational structure and culture. Westrum addresses two issues in his paper: how automation may help resolve problems of information flow and consciousness, and how the organizational structures within air traffic control and the limitations imposed may lead to ignoring problems; he concludes that future systems, if they employ automation successfully, should involve a more effective consideration of consciousness and a better recognition of the kinds of management and decision making that are possible, given the prevailing organizational structures. Kaplan draws attention to those human factors areas related to air traffic control that are susceptible to cultural influence and to the need to recognize how and under what circumstances such cultural influences result in changes relevant to air traffic control; he deals not only with obvious cultural influences, such as language, but also with subtler issues, such as cross-cultural differences in stress aetiology. Harss also considers organizations and their structure, but traces their influence on workspace design and on conditions of employment; her paper argues persuasively that it is essential to view human­machine interactions within their broader organizational contexts.

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Selection

The papers in this section deal with the selection of air traffic controllers. Della Rocco considers the desirable impact of more automated systems on the selection procedures for controllers - by looking at the evolution of the present selection procedures historically, reviewing the current selection criteria and programs, considering how automation may be applied to the selection procedures themselves, and then extrapolating what the future selection needs are likely to be. Wing, in her comprehensive review of the state-of-the-art of air traffic control selection, also discusses the issues of validation and brings out the complexity of air traffic control in relation to the selection procedures for it, since most jobs involve a considerable variety of tasks. Nyfield describes a program of selection and research to choose appropriate controllers for more automated future air traffic control systems, setting this in the context of preselection procedures, interviews, and test and simulation measures which may be used to assess various relevant factors, the aim being not only to adapt selection procedures more appropriate for future systems with more automated jobs, but also, in the process, to develop and validate better selection tools. EiBfeldt reviews the basic traits in the psychological selection procedures that have evolved in West Germany for air traffic controllers and, from this point of view, considers the changes needed to match controller selection with envisaged change requirements of more automated systems.

Training

The ninth section is concerned with air traffic control training. Baldwin's paper addresses the definition of training requirements in air traffic control and the methods of ensuring that requirements have actually been met. This paper views the problem from the Eurocontrol perspective where controllers from both the Eurocontrol and other nations are trained; he also considers other related issues, such as on-the-job training and the provision of stand-alone supplementary training devices to enable controllers to practice and hone their skills. Smith considers the effects of automation in air traffic control in the United States, first discussing predictable factors which must be taken into account (such as new training requirements, training costs, expected shortages of controllers, and demographic changes), then describing the Federal Aviation Administration's future policy on training, including ways in which automation is intended to help learning assessments during training and to adapt the training methods and techniques to the individual learning requirements of each student. He provides a list of individual differences that affect training and anticipates changes of emphasis in training requirements where automation could have a role. Herschler also identifies the need for new training approaches as a consequence of greater automation, placing particular emphasis on the need for more controller training in resources management, since this would be an implicit consequence of the changes automation would be expected to bring. Svatek emphasizes that resource management has become much more important and that trainers of cockpit crews are already paying more attention to the need to include cockpit management; she identifies objectives of this training, many of which clearly are applicable also to air traffic control. The paper by Chobot identifies future critical issues that must be addressed by those concerned with the planning and management of air traffic control training, discussing how training requirements should be integrated with the system acquisition process. Chobot also raises the issue of specifications and standards applicable to training and how they could be evolved and employed, as well as the roles of professional trainers during system procurement processes and the validation of training procedures.

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Speculations on the Future

A final series of papers offers unbridled speculations about the probable evolution of air traffic control during the next fifty years or so from a variety of points of view. One theme which many of them have in common is that automation might have advanced less than many would guess. In this regard, these musings are perhaps more cautious and less adventuresome than they may have been, had a similar question been posed only a few years ago.

Final Thoughts

The closing remarks attempt to summarize the flavor of the meeting and its main broad issues, points of view, and patterns of agreement, rather that picking up any of the numerous issues raised in the specific papers and discussions. They emphasize the need for caution, lest we take the effects of automation for granted and fail to identify the whole range of their consequences before introducing them.