Key performance issues in Surface Collaborative Decision Making

Surface Collaborative Decision-Making (SCDM) is a process for data exchange to improve the efficient movement of arrivals and departures on and near the airport surface. The Surface CDM Concept of Operations (the ConOps) describes a vision for data exchange as well as a process for metering the flow of departures entering the movement area in order to reduce the need for physical departure queues [1]. This departure metering capability is known as Departure Reservoir Management (DRM). Under the DRM concept, flight operators provide and maintain an updated Earliest Off-Block Time (EOBT) for each flight indicating when the operator expects the flight to be ready to push back from the gate. The DRM assigns each flight a Target Movement Area entry Time (TMAT) when departure metering is in effect. The DRM selects the timing of the TMAT's to maintain a queue at the end of each departure runway of the Target Queue Length (measured in aircraft) whenever there is sufficient demand. If the demand and capacity of each runway are as forecast, and taxi-out and related processes occur as predicted, a queue of the Target Queue Length (measured in aircraft) will be maintained. The DRM capability is expected to be implemented at several airports in 2015 as part of the Federal Aviation Administration's (FAA's) Next Generation Air Transportation System (NextGen). When the information provided to DRM contains inaccuracies, maintenance of the target queue length may be compromised. In response to updates in poor information, DRM may re-adjust TMAT's in an attempt to maintain the desired queue. Updates to TMAT's present challenges to the flight operators who attempt to orchestrate aircraft loading, gate operations, passenger communications, crew times, and a variety of other factors in order to hit their assigned TMAT's. A variety of controls is envisioned in the ConOps to allow the Departure Reservoir Coordinator (DRC) to encourage TMAT stability while maintaining the desired queue lengths. In this paper we discuss the Surface CDM Simulation, a simulation model of airport performance that can be achieved under DRM as described in the Surface CDM Concept of Operations, as well as results and insights gained from the model. We show that the concept can work very well when provided with accurate, timely information from operators, but that inaccurate information can lead to undesirable outcomes. We also find that the different TMAT stability controls provided in the ConOps are of varying effectiveness. We expect these results to be useful to future operators of Surface CDM DRM capabilities, to the designers of tools enabling Surface CDM, and to developers focused on future refinements of the Surface CDM Concept of Operations.