Scheduling models for optimal aircraft traffic control at busy airports: Tardiness, priorities, equity and violations considerations

This work addresses the real-time optimization of take-off and landing operations at a busy terminal control area in case of traffic congestion. Terminal areas are becoming the bottleneck of the entire air traffic control system, in particular in the major European airports, where there is a limited possibility to build new infrastructure. The real-time problem of effectively managing aircraft operations is particularly challenging, since it is necessary to incorporate the safety regulations into the optimization model and to consider numerous performance indicators that are important to compute good quality solutions. However, in practice there is no well-recognized objective function and traffic controllers often use simple scheduling rules. In this paper, mixed integer linear programming formulations are proposed to investigate the trade-off between various performance indicators of practical interest, while taking into account the safety constraints with a high modeling precision. Experiments are performed for the two major Italian airports, Milano Malpensa and Roma Fiumicino, by simulating various sets of random landing and take-off aircraft disturbances. Practical-size instances are solved to (near)optimality via a commercial solver. The optimized solutions are also compared with a commonly used scheduling rule. A comprehensive computational analysis makes possible the selection of those solutions that are able to find a good compromise among the various indicators and, consequently, the investigation of the most representative formulation.