EUROPEAN ORGANISATION FOR THE SAFETY OF AIR NAVIGATION EUROCONTROL EXPERIMENTAL CENTRE GNSS FREQUENCY PROTECTION REQUIREMENTS

This report discusses the role of monotony in Air Traffic Control (ATC). Despite its obvious relevance as a critical individual state in air traffic controllers, monotony has not been well researched in the past. To describe evoking and contributing factors, distinguish similar critical states such as fatigue and satiation, and define countermeasures, three experimental studies were conducted with a total of 32 air traffic controllers (ATCO) in the simulated and ten ATCOs in an operational air traffic control environment. Traffic repetitiveness and (dynamic) traffic density were confirmed to evoke a state of monotony, which is indicated in reduced physiological activation, subjective sleepiness, and behavioral impairments. At the same time, reduced workload but also impaired cognitive functions were observed while fatigue increased with higher time-on-task. Higher initial recovery, the experience of flow, (dynamic) traffic density changing from low to high and active physical exercises in rest breaks were determined to have a monotony-reducing effect. Based on these outcomes, recommendations address the assessment procedures during ATC concept development as well as options for the improvement of the operational environment. The applied psychophysiological multilevel-assessment method shows otherwise undetected but critical dissociations as related to the experience of cognitive functions and motivational aspects and suggests the application of assessment procedures beyond workload ratings. In the operational environment, systematic position assignment based on predicted traffic changes, the collection of initial state information, balanced active rest breaks, trainings on the role of mental sets, and the consideration of an ATCOs psychophysiological condition in incident reporting systems are proposed. A model integrating the mentioned factors supports a systematic analysis of this issue. Future research may address the role of further individual factors related to personnel selection and the long-term development of critical states. Monotony in ATC Contributing Factors and Mitigation Strategies EUROCONTROL Project SAS-2-HF-AAAA – EEC Note No. 15/06 v FOREWORD There are various problems associated with monotony in air traffic management. The first and most obvious problem is that monotony will continue to pose a challenge to the work of air traffic controllers and thus a threat to aviation safety. One could argue that increases in air traffic demand and the associated increase in controller workload will render this problem obsolete yet, unfortunately, this is not the case. Monotony due to very low traffic load will continue to play a role for example in night shifts, resulting in problems of vigilance. More importantly perhaps, monotony related to repetitive traffic patterns may play an increasing role since the need to manage higher traffic loads in busy periods might lead to increasingly uniform traffic patterns. Future levels of automation could further aggravate this problem. The second and perhaps less obvious problem is that to date we have a limited understanding of what monotony actually is, particularly in the area of air traffic management. The construct itself is not very well defined: the term monotony is sometimes used as referring to an operator’s state and sometimes to denote a situation inducing such a state. The factors contributing to an operator state of monotony are not very well understood either. And finally the consequences of monotony in terms of air traffic controllers’ performance are not fully understood. A further problem might become more apparent as soon as the factors contributing to monotony and the impact of monotony on operator performance and well-being will be better researched, namely the prevention and mitigation of monotony. The first solution that comes to mind would be to avoid work situations proven to increase monotony and impair performance. However, in some instances that may be either impractical or simply impossible. Whilst there is a sense that mitigation may help in such cases we have a very poor understanding of how we can mitigate monotony. For the above reasons EUROCONTROL has decided to sponsor research in the field of monotony through a Ph.D. scholarship for Sonja Straussberger. I had the privilege and pleasure to supervise Sonja’s Ph.D. thesis at EUROCONTROL. I am very pleased with the results of her research and I am convinced they will make a significant contribution to ATM research. Dirk Schaefer EEC Quality Manager EUROCONTROL Monotony in ATC Contributing Factors and Mitigation Strategies vi Project SAS-2-HF-AAAA EEC Note No. 15/06 Page intentionally left blank Monotony in ATC Contributing Factors and Mitigation Strategies EUROCONTROL Project SAS-2-HF-AAAA – EEC Note No. 15/06 vii ACKNOWLEDGEMENTS In a marvelous description of the history of experimental psychology in an edition published in 1956, Edward Boring determined two limitations for scientific advance. The first one is ignorance, which means that discovery depends on another discovery being made to open its way. The second one is when discovery is limited by the habits of thought that pertain to the culture of any region or period. Boring called this phenomenon Zeitgeist. With this statement in mind, I am in the pleasant situation to acknowledge the aid and cooperation of numerous persons who enabled research on a subject which was trying to overcome these limitations. First of all, I am indebted to my supervisors, Professor K. Wolfgang Kallus, Department of Work-, Organizational and Environmental Psychology at the Karl-Franzens-University Graz, for the academic supervision, and Dr. Dirk Schaefer, EUROCONTROL Experimental Centre, Brétigny sur Orge, for the industrial supervision. I was fortunate to have the inspiring guidance and encouragement of two exceptional thinkers, who made it possible to arrange this research thanks to their unbureaucratic, flexible, and open attitudes. Furthermore I owe a very special vote of thanks to Professor Dr. Peter Jorna and Mr. Alistair Jackson for taking their time for encouraging statements, the reading and assessing processes and the discussion. Their creative minds gave me valuable insights in relevant relationships. My expression of thanks is long over-due to numerous air traffic controllers and experts who patiently and curiously participated in the data collection, the study preparation or the completion process. This also includes the persons who enabled access to control centers or volunteered in the local organization of the studies. Also, without the kind support of many colleagues at EUROCONTROL the current work would not have been possible. This research was funded by EUROCONTROL Experimental Centre and enabled by the progressive engagement of proactive people who made this work possible. Hopefully, many students will be able to make use of such an opportunity in future. Finally, special thanks are due to those who supported me personally. My partner Laurent for his never-ending understanding, my family for supporting my career, and my friends for who distance does not matter and who have been there to help out any time. The opportunity to conduct the studies autonomously and learn greatly contributed to develop a better understanding of science in an applied field and to take the responsibility work psychologists have representing the human component in a technical field. More than anything, the work reinforced my understanding of the significance of scientific ethics in applied environments. This approach was also significantly influenced by the critical discussion of Schmidtke in 2002 of research trends in the field of ergonomics and the present disinformation in publications. He emphasized the responsibility of the researcher to carefully apply scientific methods for the scope of increasing knowledge that can be applied to solve practical problems. Certainly, a lot of people are involved in the completion of such a big work. As it is not possible to mention all of them by name on one page, everyone else who is concerned definitely will know that these special thanks are TO YOU. EUROCONTROL Monotony in ATC Contributing Factors and Mitigation Strategies viii Project SAS-2-HF-AAAA EEC Note No. 15/06 Page intentionally left blank Monotony in ATC Contributing Factors and Mitigation Strategies EUROCONTROL Project SAS-2-HF-AAAA – EEC Note No. 15/06 ix SUMMARY Despite the obvious relevance of monotony in the field of air traffic control (ATC), it has not been well researched in the past. One of the reasons is related to the unclear use of monotony to designate the task characteristics as well as the individual reactions to these characteristics. At the same time, the more frequently addressed concepts of boredom, underload, and low vigilance were not clearly distinguished and kept apart from critical states such as fatigue and satiation. While these states are similar in appearance, the occurrence of either state requires different countermeasures. Moreover, existing research results cannot be directly applied to understand monotony in ATC, as they were obtained in different industries or focused on isolated components. In addition, previously developed models to explain the effects of task execution on performance and individual states are often restricted on few components and thus do not well represent the conditions contributing to monotony. For the current work, a framework was used that clearly distinguished between the description of task characteristics in terms of uneventfulness and repetitiveness and exclusively used monotony for the description of an individual state. Based on research results obtained by Bartenwerfer (1957), monotony was characterized by physiological deactivation, increased feelings of tiredness and boredom, and fluctuating performance. Under consideration of individual and organizational factors, the framework allowed