Sensitivity Analysis of Potential Wake Encounters to Stochastic Flight-Track Parameters

Many NextGen technologies and concepts, when implemented, will change the underlying stochastic nature of flight tracks. This paper investigates how changes in the stochastic variability of flight tracks have the potential to impact the probability of potential wake encounters. We investigate these relationships for a single runway and for parallel runways. The results show that the mean and standard deviation of separation, and the vertical standard deviation are the key parameters affecting potential wake encounters. In the parallel-runway scenario, effects of crosswind and runway spacing are studied. A full factorial design is conducted to estimate the impact of parameters and their interactions, with dominating factors identified. In some cases, results can be different even for the same parameter when different circulation thresholds are used for defining wakes. Outputs from different wake models (TDAWP vs. D2P) are compared. The overall objective is to assess the sensitivity of these results to parameters of the stochastic input distributions. Keywords—wake vortices; simulation; sensitivy analysis