Is flying safe? Indeed it is -- statistics tell us that it is far more dangerous to drive a car or take the train. But flight safety does not just happen. Instead, as it is argued in this book, it is created by a well-developed air traffic control system that continues to be highly effective -- despite increasing volumes of traffic. How is this high level of safety achieved and sustained? Air traffic controllers are responsible for guiding the aircraft and organizing a safe and efficient traffic flow. Their work is highly structured, providing rules and resources helping them to organize traffic. To achieve the necessary cooperation with flight crews and other controllers necessary for a safe flow, controllers use a number of strategies. Among other things, controllers must visualize traffic and develop redundant procedures to prevent -- or deal with -- potential problems. In this work, controllers must rely on both cognitive abilities and social integrative skills. The study is based on extensive observations, videotapes and interviews of air traffic controllers and flight crews. It focuses on daily teamwork in air traffic control as well as organizational features such as rules and resources that structure the work. The double focus on both organizational structure and the dynamics of interaction among controllers makes the book pioneering in its field. Johan M Sanne is a researcher at the Department of Technology and Social Change at Linköping University, Sweden.