Flight measurement of enroute configuration wake vortex characteristics: A feasibility study

Abstract

The Flight Research Laboratory has undertaken a feasibility study into obtaining inflight measurements of wake vortex flowfields generated by jet transport aeroplanes in enroute configuration. The objectives of the study included the establishment of air traffic procedures for the usage of jet transports in commercial service as wake generators, the usage of condensation wake conditions for delineation of wake vortex regions, and the usage of FRL-developed air data and inertial data instrumentation for the accurate identification of wake vortex state parameters from the relatively small wind perturbations induced by the trailing vortices, whilst sampling around the perimeter of the delineated condensation wake domain. Using the NRC Falcon 20 as the wake sampling aeroplane, the study was conducted in two phases. The first phase studied wakes of length 1-6nm. The second phase, presently reported, studied wakes from 5 to approximately 30 nm in length. The proof-of-concept of the techniques was satisfactorily demonstrated. Condensation wake domains enabled the visual identification of the characteristic upper and lower vortex structures and instability states, and wind perturbations enabled the identification of some vortex characteristics. Results are presented, including examples of vortex strength dissipation, wake descent rates, and the details of a number of flightpath disturbances induced by close encounters with the trailing vortices. Copyright © 2005 by National Research Council Canada.