Effective radio communication between ATC and pilots has long been recognized as an important element of aviation safety. In recognition of the role miscommunications play in aviation incidents and accidents, the International Civil Aviation Organization (ICAO) recently introduced language proficiency requirements for all flight personnel in all ICAO member states. Using an effective and economical experimental paradigm, the research described here teases apart the complex combination of factors (e.g. speech rate, controller message length, English language proficiency, cognitive workload) believed to contribute to miscommunications between controllers and pilots. Misunderstandings in ATC Communication offers an in-depth report of a seminal study in aviation communication, which until now has only been available in the form of an unpublished dissertation. In addition, it offers a recent extension of that work, the authors' reflections on the research process, and a thorough review of the aviation communication literature. Graduate students and researchers who wish to address real-world problems will appreciate the simple elegance of the experimental paradigm that has been used to address a wide range of theoretical and applied interdisciplinary research questions. The book will appeal to scholars in the fields of human factors, linguistics, cognitive psychology, applied linguistics and second-language education and assessment. It is also of direct relevance to government and industry decision-makers and operators as they strive to implement the ICAO requirements, and to improve aviation safety.