Establishing an Upper-Bound for the Benefits of NextGen Trajectory-Based Operations

NextGen enabling technologies and operational initiatives seek to increase the effective-capacity of the National Airspace System. Concepts-of-operations, such as TrajectoryBased Operations, will allow flights increased flexibility in their 4-D trajectories as they traverse Center airspace. Shifting trajectories in this way can minimize the airlines operating costs (i.e., distance flown), shift the geography of Air Traffic Control (ATC) workload (i.e., sectors used), shift the time-intensity of ATC workload (i.e., flights counts per sector). This paper describes the results of an analysis of one day of operations in the NAS using traditional navigation aid-based airway routes compared to direct, i.e., Great Circle Distance, routes. The results yield: (i) a total of 598,724.8 nm (average 30.1 nm per flight) savings generated by flying direct routes, (ii) a redistribution of flights across sectors resulting in a reduction of 11% in the total time the flights in a sector are in excess of the Monitor Alert Parameters for that sector, (iii) a reduction in ATC workload reflected by a 47% drop in the number of flights requiring conflict resolution. These results indicate upper bound of benefit opportunities for both ATC and the airlines based on the introduction of flexible routing structures in NextGen.