Estimating Departure Queues to Study Runway Efficiency

Abstract

The ability to analyze the current efe ciency of surface operations is limited by the lack of availability of surface surveillance data. To study surface and departure issues and identify opportunities for automation to improve trafe c management, a method is presented for reconstructing the departure queues that existed at each runway from available information. Observations of the departure queues are of particular interest because they provide insight into the management of departures before takeoff. The method correlates pushback data and radar data to estimate the departure runway, the takeoff time, and the time at which the aircraft joins the departure queue, for every departure. By the calculation of the interval of time for which each aircraft is waiting at the runway, the departure queueat each runway can bereconstructed at every point in time. This method isused to study e ve days of data from Dallas/Fort Worth airport. Substantial departure queues and delays are observed, consistent with expectations for a hub airport. Moreover, knowledge of the departure queues provides insight into the efe ciency with which thedeparture runways wereused. Thedeparturequeues on the primary departure runways areshown to be well balanced at most times. However, during periods of time when departure demand was present at the runway, the interdeparture gaps exhibit signie cant variability. These delays between consecutive departures may indicate an opportunity for automation to increase throughput.