Sensitivity of System Performance and Equity to User Cooperation in Arrival Flow: Guidelines for NextGen

Incentives for users to take actions to seek preferential allocation of resources exist when demand for air transportation resources (e.g. slots at metering fixes) exceeds the available capacity. Researchers have documented actions by users of the National Airspace System (NAS) to advantageously position a flight for a preferential slot allocation through the First-Come-First-Serve (FCFS) allocation used by Air Traffic Control (ATC). NextGen concepts-of-operations (e.g. 4-D trajectories) will provide alternative mechanisms for users position flights for advantageous slot allocation. Will this degrade or enhance system performance and equity? This paper describes an analysis of the impact of users positioning flights for advantageous slot allocation on system performance and equity for an arrival flow to a metering fix. The results indicate that the combinatorics of all possible FCFS allocations create a range of performance and equity. Analysis demonstrates that user positioning for advantageous slot allocation under FCFS represents a subset of the possible combinations of FCFS slot allocations and does not result in degraded performance or equity. A case-study analysis of an arrival flow for La Guardia demonstrates that system performance and equity are robust to user positioning for advantageous FCFS slot allocation. The implications of these results for NextGen concepts-of-operations is that although the mechanisms for advantageous positioning for FCFS allocation will change, the impact on system performance & equity will not. In addition, there is evidence that the NextGen availability of system-wide information will incentivize user cooperation further enhancing NAS system performance and equity. These and other results are discussed.