Lateral attenuation of aircraft sound levels over an acoustically hard water surface : Logan Airport study

During the summer of 1999, in order to examine the applicability of currently available mathematical models of lateral sound attenuation, a noise measurement study was conducted at Logan International Airport in Boston, Massachusetts. It was revealed through analysis of the data collected that lateral attenuation is a function of the location of the engines on the aircraft, i.e., tail-mounted versus wing-mounted. In addition to that included in existing aircraft noise models, attenuation for aircraft with tail-mounted engines was found to agree with the published literature. For wing-mounted engines, attenuation was found to be less than that documented in the literature. A general under-prediction of side-line noise by the existing noise models is the result of this lower lateral attenuation for aircraft with wing-mounted engines.