Increased Approach Efficiency via Preselected Fixed Flight Path Angles

The aviation industry has long pursued efficiency improvements for economic reasons. In recent years, ecological concerns have gained increasing political importance, with European aviation mandated to achieve climate neutrality by 2050 through net-zero emissions. Enhancements in air traffic control are expected to play a role in achieving the required reductions. Research has already focussed on the savings potential of more efficient descent flights. Currently, aircraft often interrupt their descent after leaving cruising altitude, sometimes with several horizontal flight phases, which is less efficient than a continuous descent. To address this, Continuous Descent Approaches (CDA) were introduced, allowing for uninterrupted descent. However, practical implementation has revealed that CDAs significantly reduce the predictability of flight trajectories, which in turn lowers airspace and airport capacity. As a result, CDAs are currently only employed during periods of low traffic volume. Over the past few years, research has led to an improved CDA procedure, the Fixed Flight-Path Angle Approach (FPA). In principle, this is also a continuous descent, but with a predefined geometric angle. These approaches are flatter than a typical CDA, but are more predictable. FPAs can therefore be understood as a compromise between efficiency and predictability. This research work deals with whether a connected traffic situation can be solved completely conflict-free with the help of FPAs, thereby increasing efficiency compared to the status quo. To this end, a comprehensive simulation environment was developed, which was used to analyse four different scenarios at Frankfurt and Leipzig airports. The simulated trajectories were compared with the original trajectories obtained from Automatic Dependent Surveillance - Broadcast (ADS-B) data, focusing on flight time, distance, and fuel consumption. The present modelling demonstrated that all scenarios considered can be solved without any conflicts. Overall, a lower average fuel consumption was observed for three out of four scenarios while maintaining the original capacity of the airport.