Implementation of a Trajectory Prediction Function for Trajectory Based Operations

Abstract

This paper describes the implementation and evaluation of a trajectory prediction function. This function is a critical component of tactical flight management, a new concept that can increase the resiliency and robustness of trajectory based operations through a paradigm shift that improves Flight Management System (FMS) compatibility with tactical operations. The trajectory prediction function generates and continually updates the fourdimensional flight path that will be flown by the FMS. This motion-based trajectory represents an extension of the aircraft’s current state, and incorporates control laws, mode transition logic, and drag estimation as part of the prediction. The predicted trajectory is then displayed on navigation and vertical situation displays in an effort to reduce mode confusion occurrences and increase situational awareness of what the automation is doing now and what it will do in the future. These display features were evaluated in the Advanced Concepts Flight Simulator at NASA Ames Research Center to investigate the impact on flight crew energy state awareness when operating in the highly constrained and dynamic environment of the Next Generation Air Transportation System. Commercial airline crews flew multiple optimized profile descents under two conditions. In one condition, crews were presented with standard navigation displays, including a Vertical Situation Display (VSD). In the second condition, trajectory predictions were added to both the lateral map display and the VSD. Results show that predictive trajectory displays have the potential to improve situational awareness of the future automation mode and energy state of the aircraft, and that prediction accuracy and computational times are sufficient to support more advanced use in tactical flight management.