Using Multilateration Data in Probabilistic Analysis of Wake Vortex Hazards for Landing Aircraft

Abstract

Wake vortices are a safety hazard to landing aircraft. A landing aircraft that encounters a wake may roll; this might result in a fatal crash if the roll is severe enough or if the aircraft is low enough to the ground. Therefore, aircraft are separated by a sufficient distance to ensure that wakes have time to decay in strength. However, because of the inherent variability in wake behavior and aircraft separation and position, there is still a possibility for a wake encounter. To estimate the probability of such encounters, a hybrid simulation methodology is presented. The approach is hybrid in the sense that part of the simulation is conducted by using a direct data feed of flight-track data, and the other part is obtained by simulation of wake-evolution models. The approach is demonstrated on a 1-week sample of flight tracks to predict the frequency of potential wake alerts. A wake alert is defined as an event in which the trailing aircraft is in a region of space where the wake is likely to be. The results depend on atmospheric conditions and other model parameters.