PARAMETRIC STUDY OF STOL SHORT-HAUL TRANSPORT ENGINE CYCLES AND OPERATIONAL TECHNIQUES TO MINIMIZE COMMUNITY NOISE IMPACT

摘要

The main goal of this study was to investigate the effect of air-craft operational techniques in the terminal area on community noise impact of future short-haul aircraft. One mechanical-flap (MF) aircraft and one externally-blown-flap (EBF) aircraft were used to study the noise impact at four U.S. airports:Hanscom Field (Boston);Washington National;Midway (Chicago);and Orange County (California). The EBF aircraft was the final design E-150-3000 aircraft developed during the NASA STOL Systems Study, Reference 1.nWith the exception of Washington National (DCA), the study showed that a reduction of approximately 40 percent in the number of people highly annoyed (as defined in the study) can be obtained by using these operational techniques. At DCA the number of people highly annoyed using the standard procedure was quite low, but it is significant that the minimum-impact case for Runway 36 reduced the number of people highly annoyed to zero by using a power cutback and a turning departure path. The evaluation procedures and methodology developed in this study represents an advance in acoustical state-of-the-art and should provide an effective and useful tool for deter¬mining aircraft noise impact upon the airport community.nA study was conducted to determine the sensitivity of the NASA STOL Systems Study final design E-150-3000 aircraft to changes in wing sweep and thickness ratio. During the NASA STOL Systems Study, it was determined that this aircraft was relatively insensitive to aspect ratio and that AR = 8 was near optimum. Similarly, it was found that wing sweep and wing thickness had little effect and that changing to an optimum wing (primarily a reduction in wing sweep) would result in approximately a one to two percent reduction in DOC. The insensitivity to wing geometry is partly due to the engine being selected for a field length and sideline noise requirement rather than for a cruise speed requirement.