Delay Sensitivity to Call For Release Scheduling Time

A goal of any precision departure concept, such as NASA Precision Departure Release Capability, is to improve throughput, efficiency and capacity by integrating departure, arrival and surface operations. This kind of concept is believed to have the potential of increasing flight efficiency and throughput by not missing assigned overhead-stream or arrival-stream slots. In the current Call For Release scheduling, a slot can be missed because of airport-departure delay, which is the sum of gate-departure delay, ramp delay, and taxi-out delay. This delay can be reduced by improved precision departure scheduling. The main thrust of the paper is to determine the delay-cost impact of Call For Release scheduling before gate-push-back and at gate-pushback. Seven different variations of scheduling algorithms were used in the simulation. Results reported in the paper considers 37,346 flights in the National Airspace System for one day in January 2011. Approximately 1,500 airports were included in the simulation. Results show that there is no significant benefit of scheduling before gate-push-back as opposed to at gate-push-back under assumed gate-departure and taxi-out time uncertainties, assuming a Call For Release is strategically done for all departures from all airports. However, if there were no gate-departure and taxi-out time uncertainty, which is unlikely in reality, the maximum benefit of scheduling an hour before gate-push-back is limited to 6.8% reduction in weighted delay (2*airborne delay + ground delay) compared to delay resulting from scheduling at gate-push-back.