Effect of LNAV and VNAV Equipage on Time-Based Scheduling

Abstract

This paper evaluates the effect of Lateral NAVigation (LNAV) and Vertical NAVigation (NAV) equipage on the performance on time-based scheduling. The paper relies on two companion papers: (i) the first paper develops a high-fidelity simulations model of LNAV + VNAV, and (ii) the second paper develops a realistic spatio-temporally correlated model of wind uncertainty. Two different Monte Carlo simulation frameworks are used to evaluate the effect of LNAV + VNAV equipage on time-based-scheduling. The first Monte Carlo simulation framework is used to evaluate the time-of-arrival uncertainty for flights equipped with LNAV + VNAV capability. This Monte Carlo simulation uses a point-mass simulation model of the aircraft equipped with LNAV + VNAV and flying through spatio-temporally correlated wind uncertainty fields. The second Monte Carlo simulation evaluates the effect of LNAV + VNAV equipage on the performance of time-based scheduling. NASA's Stochastic Terminal Area Scheduling and Simulation (STASS) software is used for timebased scheduling and terminal area traffic simulations. Terminal-area traffic Monte Carlo simulations are conducted for 1.0x, 1.5x, and 2.0x demand ratio at San-Francisco International Airport (SFO), Los Angeles International Airport (LAX), and Dallas Fort Worth International Airport (DFW). Results illustrating the effect of LNAV + VNAV equipage level (0%, 25%, 50%, and 75%) on delay, throughput, and the number of separation violations are presented in the paper.

Design and Evaluation of LNAV/VNAV Guidance Algorithms for Time-of-Arrival Error Characterization

“…The following state components are used in the simulation: State components (26) where are the position coordinates in a Cartesian frame of reference; is the altitude; is the air-relative heading angle;…”