Airborne 4-dimensional trajectory management

The paper describes a prototype of an airborne Flight Management System (FMS), supporting initial four-dimensional (I-4D) flight operations. The I-4D operations are based on airborne computed predictions that are used in ground systems. The goal is to establish far in advance a sequence for all aircraft converging to a merging point in a congested area. After coordination between the ground systems and aircraft, a time constraint at a merging point is assigned to each aircraft. As compensation, aircraft are allowed to fly their optimum profile up to that point, without any vectoring instructions from controllers. The prototype is based on Airbus A320 FMS software which has been enhanced by the I-4D features like Required Time of Arrival (RTA) in descent flight phase, reliable RTA window computation, and data link enhancements. Example of operational scenario is presented. The prototype has been tested with actual hardware, in an Airbus cockpit simulator and in flight as well.