Estimating Aircraft Landing Weights from Mode S Data

Abstract

Aircraft weights prior to touchdown are assessed employing equations suggested for estimates of descent speeds depending on aircraft gross mass following BADA (Base of Aircraft Data). The required aircraft type, calibrated airspeed and air density data are derived from Mode S data protocols. Landing weights of 3328 aircraft approaching Vienna airport, provided by Austrian Airlines, serve as reference gross masses. Average aircraft masses during final approach vary between 85% and 93% of the maximum landing weight depending on the aircraft type. A simple correction for the observed inclination of pilots to fly somewhat faster than prescribed in reference handbooks eliminates the bias of the mass estimates in the current data base, while the respective standard deviation amounts to approximately 5%.