Drawn from research papers presented at two closed-forum research meetings sponsored by the U.S. Federal Aviation Administration and the European Eurocontrol, this new book explains the technical nature of a very complex international air transportation system. It reports on new research that is furthering the evolution of the international air transportation systems. The book promotes our understanding of the technical attributes of delay and its economic effects on aviation-related business. The application of mathematical analyses and principles is a growing area of aviation. This book contributes to expanding our understanding of this area. It also provides approaches to airspace management and new roles for controllers and pilots. Students, engineers, and policy makers will appreciate the use of real-world data, case histories, and extensive graphics of operations, airports, delays, flight tracks, etc.