Plate Lines Reduce Lifetime of Wake Vortices During Final Approach to Vienna Airport

Abstract

To mitigate the risk of wake vortex encounters during final approach, so-called plate lines have been developed. Wake vortices generated by landing aircraft induce secondary vortices at the plates’ surfaces that approach the primary vortices and trigger premature wake vortex decay. Each plate line consists of several upright plates that are installed underneath the approach glide path. While the plate line extends perpendicular to the flight direction, its individual plates are oriented in parallel to the runway centerline. In order to obtain the approval of the authorities for the installation of the plate lines at runway 16 of Vienna International Airport, the plate design had to comply with airport requirements like obstacle clearance, stability, and frangibility. During a six-month campaign wake vortex behavior with and without plates was measured simultaneously by three lidars completed by a comprehensive suite of meteorological instrumentation. A preliminary analysis of 430 measured wake vortex evolutions indicates that the plate lines reduce the lifetime of longlived vortices in a safety corridor along the final approach on average by more than 30%. More comprehensive analyses are underway and will be presented at the AVIATION Forum 2020 in Reno.