Strategic flow management for air traffic control

One of the most important functions of air traffic management systems is the assignment of ground-holding times to flights, i.e., the determination of whether and by how much the take-off of a particular aircraft headed for a congested part of the ATC system should be postponed to reduce the likelihood and extent of airborne delays. In this paper, the authors will present an analysis of the fundamental case in which flights from many origins must be scheduled for arrival at a single, congested airport. They will describe a set of approaches for addressing a deterministic and a stochastic version of the problem. A minimum cost flow algorithm can be used for the deterministic problem. Under a particular natural assumption regarding the functional form of delay costs, a very efficient, simple algorithm is also available. For the stochastic version, an exact dynamic programming formulation turns out to be impractical for typical instances of the problem and the authors present a number of heuristic approaches to it. The models and numerical results suggest the potential usefulness of formal decision support tools in developing effective ground-holding strategies. Many methodological and implementation issues, however, still require resolution.