Airport Ground Holding with Hierarchical Control Objectives

Disruptions in the air transportation system, perhaps due to extreme weather, often result in unexpected, or off-nominal, delays at airports. A resilient air traffic management system seeks to restore airport delays to their nominal values quickly after such disruptions. Two primary factors make the design of efficient recovery algorithms for air transportation networks challenging: the lack of a high-fidelity model for predicting and controlling airport delay dynamics, and poor computational tractability of large-scale flight rescheduling optimization problems. We propose a two-stage hierarchical control strategy for rescheduling aircraft (i.e., assigning delays) after network disruptions. Our high-level planner leverages a low-fidelity approximation of airport delay dynamics to propose a reference plan based on user preferences. This reference plan accounts for complex objectives such as ensuring a “smooth” redistribution of delays across airports (quantified by the total variation). The low-level controller then solves the multi-airport ground holding problem (MAGHP), augmented to track the reference plan. The solution to the augmented MAGHP yields a revised flight schedule with lower total variation than the original MAGHP, while still satisfying operational constraints. We illustrate the benefits of our proposed methodology using six disruption case studies of the National Airspace System (NAS).