Assessment of Aircraft Separation Reduction Potential for Arrivals Facilitated by Plate Lines Following the RECAT-EU Methodology

Abstract

Wake vortex related minimum aircraft separations for arrivals were evaluated utilizing plate lines. A plate line consists of a series of vertical plates placed in front of the runway that accelerate the decay of wake vortices. This study evaluates the potential to reduce minimum aircraft separations and the potential to increase safety due to the accelerated vortex decay. The presented method follows the methodology of the proposal for revised wake turbulence categorization RECAT-EU as much as possible in order to be compliant with the respective certified safety assessment. Wake vortex data measured by lidar with and without plates during a measurement campaign at Vienna International Airport, Austria, were used to generate generic non-dimensional decay curves for all captured aircraft types under so-called reasonable worst-case weather conditions with and without plates. The observed wake vortex behavior without plates was fitted to the generic decay curve from RECAT-EU. The application of the same method to the measurements with plates yields a generic decay curve representing the accelerated decay triggered by the plates. Applied to the RECAT-EU minimum separation scheme potential separation reductions ranging from 12% to 15% were evaluated. The same method was applied to the RECAT-EU-PWS pairwise separations, yielding a potential separation reduction due to the plates of 12% to 24% (average 14.8%) or a potential circulation reduction of about 20% to 30%. An assessment of the associated encounter risk showed significant benefits from plate lines indicating that the collaborative introduction of RECAT-EU-PWS together with plate lines may bring about increased airport capacity and safety at the same time when comparing it to the RECAT-EU scheme which is already operational at four European airports.