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 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. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Bruce M. Alberts and Dr. William A. Wulf are chairman and 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 House Public Works and Transportation Committee, then chaired by Congressman Oberstar, that efforts to modernize and further automate the air traffic control system should not compromise safety 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 humans and the tools provided to assist in accomplishment of system tasks.

The first phase of the panel's work focused 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 of the first phase were 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 results of the panel's deliberations for the first phase were reported in Flight to the Future: Human Factors in Air Traffic Control.

The second phase has assessed future automation alternatives and the role of the human operator in ensuring safety and efficiency in the air traffic control system. In the second phase we examined the human factors aspects of automation both for the general development of new systems and for specific, key subsystems at various stages of testing and implementation. A critical focus of the second phase has been the interaction between the automation and the controller on the ground and the automation and the pilot in the cockpit.

This report provides the results of the panel's deliberations during the second phase. The first part of the report discusses fundamental human factors issues pertaining to automation of air traffic control functions and reviews several emerging technologies that may support automation of future air traffic control functions. The second part of the report reviews current and future initiatives and programs that automate functions for surveillance, communication, flight information, immediate conflict avoidance, strategic long-range planning, training, and maintenance. The third part of the report discusses the integration of research and development as well as human factors issues with respect to the free flight initiative, and also presents the panel's vision of the evolution of automation in the national airspace system in the next decade. The final chapter presents the panel's key conclusions and recommendations. Research results available after August 1997 were not reviewed by the panel for this report.

We direct this report to 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 making readers to the Summary and Chapter 10, which present our conclusions and recommendations; to the introduction to Part II, which provides an overview of the trend toward automation in the national airspace system; and to Part III, which presents discussions of management issues, program development issues, free flight, and a future vision.

Many individuals have made contributions to the panel's thinking and to various sections of this report by serving as presenters, advisors, and liaisons to useful sources of information; all of these individuals provided us with valuable information. A list of contributors and their affiliations is presented in Appendix B. A few people 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 Federal Aviation Administration: to Mark Hofmann and to Maureen Pettitt for their consistent support of the panel's activities; to David Cherry for helpful and timely responses to numerous requests from the panel for documentation and technical information, and for arranging visits to FAA facilities and discussions with subject-matter experts; and to Michael McAnulty for providing and for coordinating presentations to the

panel at the FAA Technical Center. We are especially grateful to Neil Planzer, director, Air Traffic System Requirements Service at the Federal Aviation Administration, for his continued interest in and guidance to the panel.

We would also like to extend our thanks to Brian Hilburn, at the National Aerospace Laboratory (NLR) in the Netherlands, for contributing to the section on interactive planning and for providing materials on European developments in air traffic control automation; and to Jonathan Taylor, at the Massachusetts Institute of Technology, for contributing to the section on the global positioning system.

This report is the collective product of the entire panel, and each member took an active role in drafting sections of chapters, leading discussions, and/or reading and commenting on successive drafts. The first part of the report, which discusses automation issues and principles, as well as emerging technological resources, reflects significant contributions by Raja Parasuraman, Thomas Sheridan, Tora Bikson, Robert Helmreich, Todd LaPorte, Marvin Cohen, and David Hopkin. The second part, which reviews current and envisioned automation initiatives for air traffic control, reflects significant contributions by Paul Stager, Earl Wiener, Charles Aalfs, Richard Stone, Joseph Pitts, James Danaher, Laurence Young, and Diane Damos.

Staff at the National Research Council made important contributions to our work in many ways. As study director, Anne S. Mavor managed the overall course of the study, ensured that the work was done carefully and well, and made intellectual contributions that can be found in every chapter of the report. James P. McGee worked closely with the study director on all aspects of the study, taking particular responsibility for drafting descriptions of a number of the systems presented in Part II as well as the material on integration of research and development. Jerry Kidd contributed insights across many areas of the report and drafted sections that address conflict avoidance technologies and the application of research methodologies. We would also 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 Susan McCutchen, the panel's senior project assistant, who was indispensable in organizing meetings, arranging travel, compiling agenda materials, managing the exchange of documentation across the panel, and preparing the final manuscript; and to Christine McShane, who edited and significantly improved the report.