This book covers the Air Traffic Management (ATM) environment and the controller-crew interactions. The International Civil Aviation Organization (ICAO) regulations and organizational procedures are also presented in a succinct manner so that novel and experienced aviation practitioners appreciate how safety organization affects their cognitive performance. The book distills theoretical knowledge about human cognition and presents real examples and case studies to help readers understand how air traffic controllers make sense of difficult situations, make decisions under time pressure, detect and correct their errors, and adapt their performance to complex situations.