Factors Influencing the Noise Explosure under the Landing Path for Jet Transport Aircraft

摘要

On the basis of available acoustical data calculations have been made to determine the quantitative effect on the noise exposure under the landing path of changes in runway threshold location, glide slope angle, and engine power setting. Each of these factors has been examined independently, i.e. with all other conditions held constant, for operation of a turbofan-powered Convair 990 and a turbojet-powered Boeing 707-120. Changes in noise exposure are described in terms of changes in perceived noise level and/or changes in the area enclosed by equal perceived-noise-level contours for a range in glide slope angles from 2-1/2 to 6 degrees, runway threshold displacements of 1000 feet and 2000 feet, and four different engine power settings from approximately 60% thrust downward. The results can be generalized to apply to essentially all four-engine commercial jet airliners in operation today. They provide the basis whereby changes in these factors can be evaluated in terms of their effectiveness in reducing noise exposure alone. Further, trading relationships among changes in these factors can be derived from the data. (Author)