Estimation of Potential Conflict Rates as a function of Sector Loading

Automated separation assurance systems are being developed to reduce controller workload and increase airspace capacity of the National Airspace System (NAS). To evaluate these systems, a measure for conflict risk is required. The objective of this analysis is to estimate the rate at which flights enter a course of potential conflict or collision under different traffic loads. Conflict rates are estimated under the assumption of no conflict resolution. In other words, the analysis is aimed at estimating precursors to actual conflicts. The conflict rates are estimated (a) using a NAS-wide simulation, (b) for a futuristic NAS-wide 1.5X traffic schedule, (c) for airway routes and great circle routes, (d) for different conflict-volume dimensions (conflict types), and (e) for different sector traffic loads. Conflict types include loss of separation (LOS), critical loss of separation (CLOS), near mid air collision (NMAC), and mid air collision (MAC). The simulation of flight trajectories and detection of conflicts are done using Future Air Traffic Management Concepts Evaluation Tool (FACET). A hybrid analyticalsimulation approach is also used to estimate the rate of MACs. A key result is that the rates of NMACs and MACs for the airway routes are higher than the corresponding rates for the greatcircle routes. The results also show that conflict rates follow the quadratic relationship with respect to flight count.