Implementing time based CDA operations in a medium-high density ATM environment

Within the present air traffic management (ATM) system, a desired high capacity rate of continuous descent operations, flown from top-of-descent to final approach, is not yet feasible during daytime operations at the major airports. A concept of operations is described aiming at reducing the aviation environmental impact through better planning and predictability in the (extended) terminal area. This should enable a higher rate of Continuous Descent Approach (CDA) profiles while maintaining at least the same rate of Continuous Climb Departures. The work was performed within the ERAT project (Environmentally Responsible Air Transport), sponsored by the European Commission. The project aims to achieve enhanced climb and descent services as defined by SESAR and for implementation of operational improvements in the short to medium term. Key elements in the concept of operation for medium to high density CDA operations are time based operations using Controlled Time of Arrival (CTA), applying advanced arrival management and trajectory prediction, as well as integrated controller support tools. The evaluations have definitely proven benefits of the concept regarding predictability and efficiency. The concept and the advanced arrival management tool that have to support the concept seem to cater for possibilities to reach higher efficiency.