ABSTRACT
Technology allows aircraft to broadcast information about its own-ship position and velocity to surrounding aircraft, and to receive similar information from surrounding aircraft. This development has stimulated the rethinking of the overall concept for future Air Traffic Management (ATM), e.g., to transfer responsibility for conflict prevention from ground to air. As the aircrews thus obtain the freedom to select their trajectory, this conceptual idea is called free flight [57]. It changes ATM in such a fundamental way, that one could speak of a paradigm shift: centralised control becomes distributed, responsibilities transfer from ground to air, fixed air traffic routes are removed, and appropriate new technologies are brought in. Each aircrew has the responsibility to timely detect and solve conflicts, thereby assisted
by navigation means, surveillance processing, and conflict resolution systems. Due to the potentially many aircraft involved, the system is highly distributed. This free flight concept idea has motivated the study of multiple operational concepts and implementation choices [33], [37], [41], [44], [54]. One of the key outstanding issues is the safety verification of free flight design, and in particular when air traffic demand is high.
