This is the fourth edition of the acclaimed volume of Milde’s International Air Law and ICAO, first published in 2008. It has now been fully revised by Dr. Attila Sipos, LL.M., to take the latest developments and events into account. Specialized legal literature dealing with different aspects of international air law is scarce, the developments often overtake the existing writings and there is a continuous need not only for updating but also for future-oriented thinking. There is a practical need for a compact but exhaustive and easily comprehensible textbook or reference book that deals with the most general aspects of international air law, as well as with constitutional issues and the law-making functions of the International Civil Aviation Organization (ICAO). This book fills this gap as a general treatise aimed at the needs of scholars and practitioners, government authorities, aviation industry experts and journalists. This book was motivated by Prof. Milde’s 25 years of experience (1966-1991) in the Secretariat of ICAO in Montreal – his last eight years as Director of the Legal Bureau. In equal measure the inspiration for the content of this book came from the author’s academic work. He was the Director of the Institute of Air and Space Law (IASL) of McGill University (1989-1998) and was teaching graduate students from different parts of the world and different legal cultures until 2006. The international civil aviation community will never forget Michael Milde's extraordinary professional achievements and visionary academic activities. This book is its eloquent testimony.