Air traffic management based on 4D-trajectories: requirements and practical implementation

The current Air Traffic Management (ATM) functional approach is changing: ‘time’ is now integrated as an additional fourth dimension on trajectories. This notion will impose on aircraft the compliance of accurately arrival times over designated checkpoints, called Time Windows (TWs). In this context, we review the operational concept of 4D-trajectories, by initially developing an analysis of basic requirements for their implementation in the Communications, Navigation and Surveillance (CNS) systems and then by investigating their management in the future ATM context. We focus on defining the relationships between 4D-trajectories and other concepts and systems of the future ATM framework, and the needs that it will require for its application, detailing the main tools, programs and ATM/CNS systems that must be deployed. We appraise how 4D-trajectories must be managed and planned (negotiation, synchronization, modification and verification processes). Then, based on the degradation of a 4D-trajectory, we define and introduce the necessary corrective measures by evaluating the degradation tolerances and conditions.