Trajectory-based operations — Robust planning under trajectory uncertainty

Abstract

Trajectory-Based Operations require the development and execution of a trajectory-based plan which is subject to uncertainty as a result of trajectory prediction inaccuracy and disturbances. The impact of disturbances due to conflict detection/resolution and traffic synchronization are evaluated under different levels of prediction inaccuracy through Monte Carlo Simulation. Conflicts are estimated to contribute uncertainty below a 1% speed variation for look-ahead times beyond 2 hours. Traffic Synchronization is shown to further amplify any trajectory prediction inaccuracy. A process for the incremental assignment of delays is described using an optimum delay margin and credit to ensure a stable delay is assigned. The approach is shown to allow a shift from costly tactical delays to strategic, equitably assigning delays across stage lengths and providing significantly more predictable delays per flight prior to departure. Benefits are shown to increase as trajectory prediction accuracy is improved.