Lower cost departures for airlines: Optimal policies under departure metering

Departure metering is an airport surface management procedure that limits the number of aircraft in the runway queue by holding aircraft either at a predesigned metering area or at gates. Field tests of the procedure have shown significant fuel savings, implying that the procedure can play an important role in the Next Generation Air Transportation System being implemented in the U.S. In this paper we study optimal departure operations at airports in the context of departure metering. More specifically, we develop a stochastic dynamic programming framework for tactical management of pushback operations at gates and for determining the optimal number of aircraft to be directed to the runway queue from the metering areas. We introduce four easy-to-implement departure metering policies, and perform comparative analyses between these practical policies and the numerical-optimization based policies. In addition, from a strategic perspective, we identify optimal capacities for metering areas to be used as part of departure metering implementations. Overall, we find that the annual fuel and operating savings for airlines could be around $1.7 million if our proposed policies are implemented at the Detroit Metropolitan Wayne County Airport. Such policies can also be adapted by other airports to improve the overall efficiency of surface traffic management and departure operations.