Robust Flight Trajectory Optimization during Approach for efficient Aircraft Sequencing and Spacing considering Uncertainties

• Applicant: Professor Dr.-Ing. Hartmut Fricke
• Subject Area: Traffic and Transport Systems, Intelligent and Automated Traffic
• Term: since 2026
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 564608603

This research proposal aims to enhance the potential of aircraft trajectory optimization in the context of Air Traffic Management (ATM). The direction of the enhancement is twofold: robust optimization for multiple aircraft forming an arrival sequence, and integration of trajectory optimization into sequencing and required safe spacing between the entities. Within „Strategy A", we develop a robust trajectory optimization method to allow for considering multiple aircraft. Conventional stochastic or robust trajectory optimization predominantly focused on a single aircraft and avoided tackling the problems arising with multiple aircraft such as integration of individual trajectories into air traffic management. The novel optimization method is based on the Optimal Control (OC) theory, a robust trajectory optimization method that the applicant has been studying for years. Uncertainties from more various sources than the conventional stochastic trajectory optimization are modeled and considered in the optimization (e.g., weather forecast, aircraft mass assessment, cruise speed and altitude, initial mass). Within "Strategy B", we develop a method to integrate the robust trajectory optimization into a sequencing and spacing mechanism. This integration shall allow for studying the inter-dependent coupling between individual aircraft trajectories (microscopic perspective) and the resulting air traffic flow (macroscopic perspective). Simultaneously, this integrated optimization method shall consider the propagation of uncertainty along individual trajectories and the traffic flow, thus helping to control the level of uncertainty in sequencing and spacing activities. With these methodological inventions, the applicant proposes novel functionalities for next-generation Arrival Manager systems (AMAN+). The new functionalities include optimal spacing between successive aircraft during descent (Strategy A) and optimal sequencing at the Final Approach Fix (FAF) (Strategy B). The applicant considers not only simple arrival-route structures but also complex and realistic trombone designs, the Point Merge System (PMS) concept, itinerary shortcuts, and multiple-runway configurations. The performance of AMAN+ functionalities shall be evaluated through simulation studies. This research project finally aims to apply the AMAN+ to a real-world use case: Leipzig/Halle Airport, while assuming a well-tailored PMS capable of considering best the OC generated descent and approach trajectories. This application will be supported on the operational data side by the Airport Operator FMAG, EUROCONTROL, DFS and the Free State of Saxony. The anticipated outcomes of this research include improved predictability of the flight trajectory, this leading to higher flight efficiency and enhanced sequencing. By integrating trajectory and sequence optimization in a single robust framework, the proposed AMAN+ shall achieve well improved performance figures.

• DFG Programme: Research Grants