The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. Upon the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Bruce M. Alberts is president of the National Academy of Sciences.

The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. William A. Wulf is interim president of the National Academy of Engineering.

The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, upon its own initiative, to identify issues of medical care, research, and education. Dr. Kenneth I. Shine is president of the Institute of Medicine.

The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academy's purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. Dr. Bruce M. Alberts and Dr. William A. Wulf are chairman and interim vice chairman, respectively, of the National Research Council.

This report is the work of the Panel on Human Factors in Air Traffic Control Automation, which was established in fall 1994 at the request of the Federal Aviation Administration (FAA). The panel was appointed to conduct a two-phase study of the human factors aspects of the nation's air traffic control system, of the national airspace system of which it is a part, and of proposed future automation issues in terms of the human's role in the system. The impetus for the study grew out of a concern by members of the Subcommittee on Aviation of the Public Works and Transportation Committee of the U.S. House of Representatives that efforts to modernize and further automate the air traffic control system should not compromise safety and efficiency by marginalizing the human controller's ability to effectively monitor the process, intervene as spot failures in the software or environmental disturbances require, or assume manual control if the automation becomes untrustworthy. Panel members represent expertise in human factors, decision making, cognitive psychology, organization structure and culture, training and simulation, system design, controller operations, and pilot operations. The primary focus of the study is the relationship between the human and the tools provided to assist in accomplishment of system tasks.

The panel's charge calls for two phases. The first phase focuses on the current air traffic control system and its development and operation within the national airspace system from a human factors perspective. The specific purposes are to understand the complexities of the current system that automation is intended to address, characterize the manner in which some levels of automation have already been implemented, and provide a baseline of human factors knowledge as it relates to the functions of the air traffic controller in the system and the

organizational context within which these functions are performed. The second phase is to assess future automation alternatives and the role of the human operator in ensuring safety and efficiency in the air traffic control system. A critical aspect of this second phase is to examine the interaction between the automation and the controller on the ground and the automation and the pilot in the cockpit. Specifically, we plan to project future tasks and examine the consequences of automation on them, assess possible changes in the pattern of controller work and the potential effects on performance, and evaluate procedures needed for the smooth evolution of the national airspace system.

This report provides the results of the panel's deliberations during the first phase. The first part of the report presents a baseline description of the air traffic control system, the selection, training, and assessment of controllers, and the operations associated with keeping the systems and equipment functioning. The second part of the report discusses current knowledge about human factors as it relates to the air traffic controller. We begin this part with human factors principles and findings concerning the cognitive and workload characteristics of the job of the controller, working both as an individual and as part of a team. Then we examine system management, human factors considerations in Airway Facilities, and the integration of human factors research and development into the organization. Finally, the discussion of automation issues serves as a bridge to our work in the second phase. The panel's recommendations concerning human factors considerations appear in the executive summary.

We hope the readers of this report will encompass a broad audience, including those interested in the air traffic control system and its operation and policy as well as those interested in general issues of aviation psychology research and air safety. We direct the attention of our policy readers to the executive summary with our conclusions and recommendations, the chapters on system management and automation, and the final sections of each chapter that contain a brief discussion of the major points covered. Our readers from the research community are directed to the chapter details in Part II.

Many individuals have made contributions to the panel's thinking and to various sections of this report by serving as presenters, advisers, and liaisons to useful sources of information. A complete list of contributors and their affiliations is presented in Appendix B. Although all of these individuals provided us with valuable information, a few played a more direct role in the coordination of information used in the preparation of this volume, and they deserve special mention. We extend our gratitude to several individuals in the FAA and NASA: to Mark Hofmann for frequent and detailed updates on human factors issues and activities within the FAA and for consistent support of the panel's activities; to David Cherry for consistently helpful and timely responses to numerous requests from the panel for documentation and for arranging visits to FAA facilities and discussions with FAA subject-matter experts; to Carol Manning for similarly responsive requests for information and for coordinating presentations to the

panel by staff at the Civil Aeromedical Institute and the Mike Monroney training facility; and to Kevin Corker for coordinating presentations to the panel by staff at NASA Ames. We are especially grateful to Neil Planzer, director of Air Traffic Plans and Requirements for the FAA, for informative perspectives on air traffic control historical developments, challenges, and future plans and concepts.

Although this report is the collective product of the entire panel, each member took an active role in drafting sections of chapters, leading discussions, and/or reading and commenting on successive drafts. In particular, Raja Parasuraman assumed major responsibility for the chapters on automation and on workload and vigilance, Robert Helmreich for the chapter on teamwork and communication, and Paul Stager for the chapter on human factors research methodology. Charles Aalfs, Joseph Pitts, and Richard Stone provided materials reflecting operational expertise that were especially critical for the development of the chapters that describe the air traffic control system and the tasks of air traffic controllers. Tora Bikson contributed sections for the chapters on system management and system development, Marvin Cohen for the chapter on cognitive task analysis, and David Hopkin and Thomas Sheridan for the chapter on automation. Todd LaPorte provided critical conceptual and detailed considerations with respect to the issues of system reliability and organizational context, James Danaher with respect to system safety and efficiency, Earl Wiener with respect to automation and to the management of human factors activities, Diane Damos with respect to the selection of air traffic controllers, and Laurence Young with respect to historical developments in related domains.

Staff at the National Research Council made important contributions to our work in many ways. We would like to express our appreciation to Alexandra Wigdor, director of the Division on Education, Labor, and Human Performance, for her valuable insight, guidance, and support; to Theresa Noonan and Susan McCutchen, the panel's administrative assistants, who were indispensable in organizing meetings, arranging travel, compiling agenda materials, and managing the exchange of documentation across the panel. We are also indebted to Christine McShane, who edited and significantly improved the report, and to Gary Baldwin, who generously shared his wealth of knowledge and experience with respect to FAA organization, policies, procedures, and information sources.

Christopher D. Wickens, Chair

Anne S. Mavor, Study Director

James P. McGee, Senior Research Associate

Panel on Human Factors in Air Traffic Control Automation