Evaluation of scheduling methods for multiple runways

Several scheduling strategies are analyzed to determine the most efficient means of scheduling aircraft when multiple runways are operational and the airport is operating at different utilization rates. Simulation data are compared for two- and three-runway scenarios to results from queuing theory for an M/D/n queue. The direction taken, however, is not to do a steady-state, or equilibrium, analysis because this is not the case during a rush period at a typical airport. Instead, a transient analysis of the delay per aircraft is performed. It is shown that the scheduling strategy that reduces the delay depends on the density of the arrival traffic. For light traffic, scheduling aircraft to their preferred runways is sufficient; however, as the arrival rate increases, it becomes more important to separate traffic by weight class. Significant delay reduction is realized when aircraft that belong to the heavy and small weight classes are sent to separate runways with large aircraft put into the best landing slot.