Ideal free flight through multiple aircraft neighboring optimal control

The general term for any air traffic management concept that minimizes restrictions on aircraft operations while maintaining or improving upon the current level of safety is free flight. This paper proposes an ideal free night concept and develops a practical algorithm based on neighboring optimal control. The mathematical development is carried out for a two-aircraft conflict resolution scenario, followed by the presentation of a simulation example. The benefits of the resulting algorithm are that it approaches single-aircraft optimal guidance as the distance between aircraft increases, and it achieves optimal safe inter-aircraft separation while maintaining near-optimality under disturbances (e.g. initial condition and wind modeling errors)