Flight Test Preparation of a 4D-controller for time constrained Continous Descent Operations (CDO)

Within the Clean Sky European project, a flight test prepared by the German Aerospace Center (DLR) is foreseen and meant to prove the capability of flying a Continous Descent Operation (CDO) while satisfying a time constraint at a waypoint. In light of this event, the main objective of this project is the preparation and possible improvement of a 4D-Controller that enables this time constrained CDO. The main task of the 4D-Controller that must be evaluated is the transmission of advisories by the controller to a human-machine interface on board the aircraft. These advisories are the ones that the pilot will further on introduce into the main flight guidance systems of the aircraft in order to perform the time constrained CDO.\\vspace{2mm} The methodology used to evaluate the functionality of the controller has been the use of different simulation environments through witch data regarding the controller's behavior has been collected. The distinctive elements between the different simulation environments are the aircraft performance model used, the accuracy in simulating the meteorological conditions, as well as the graphic interface. Besides the controller's behavior, observations have been made regarding the human- machine interference and the robustness of the system. In all cases, the simulations have been performed in real-time and in manual mode, using a similar method as the one the pilot will use during the flight test. \\vspace{2mm} The results and observations achieved from the simulations indicate a correct behavior of the controller. The time accuracy at the control waypoint is small enough to fulfill the operational requirements from a controller point of view. The use of thrust and speedbrakes has been acceptable within the scenarios that included disturbances and null in the ones without any disturbance having observed certain differences depending on the simulation environment used. The advisories were sent by the 4D-at an acceptable rate without adding a high additional amount of workload to the pilot. These and other results are shown throughout this project.