This book offers a timely snapshot of research and developments in the area of air traffic engineering and management. It covers mathematical, modeling, reliability and optimization methods applied for improving different stages of flight operations, including both aerodrome and terminal airspace operations. It analyses and highlights important legal and safety aspects, and discusses timely issues such as those concerned with Brexit and the use of unmanned aerial vehicles.  Gathering selected papers presented at the 6th edition of the International Scientific Conference on Air Traffic Engineering, ATE 2020, held in October 2020 in Warsaw, Poland, this book offers a timely and inspiring source of information for both researchers and professionals in the field of air traffic engineering and management.