Fixed RTA fuel optimal profile descent based on analysis of trajectory performance bound

In this paper, the framework, so called Trajectory Performance Analyzer (TPA), for analyzing performance bound of descent trajectory using optimal control problem formulation is proposed. Minimum time trajectory and minimum fuel trajectory are obtained by trajectory optimizer of TPA and performance bound is determined between two optimal trajectory results. To consider effect of uncertainties from aircraft descent weight as well as effect of initial condition such as cruise speed, sensitivity analysis is performed. The feasible time of arrival to the meter fix is determined based on performance bound of the descent trajectory. To meet the scheduled time of arrival to the meter fix, fixed time RTA minimum fuel descent profile generation method is proposed. The proposed method is suboptimal minimum fuel trajectory generation method constructed with known FMS Vertical Navigation (VNAV) descent algorithms. The VNAV segments used in this method is determined by analyzing minimum fuel trajectories with fixed RTA. The numerical simulations with B737-800 and B767-400 are given to illustrate the proposed TPA framework and fixed RTA suboptimal trajectory generation method for FMS.