The purpose of NASA Contract NAS1-20090 Task 3 was to investigate the potential for noise reduction that would result from improving the high-lift performance of conventional subsonic transports. The study showed that an increase in lift-to-drag ratio of 15 percent would reduce certification noise levels by about 2 EPNdB on approach, 1.5 EPNdB on cutback, and zero EPNdB on sideline. In most cases, noise contour areas would be reduced by 10 to 20 percent. Haffner, Stephen W. Unspecified Center NAS1-20090; RTOP 538-03-15-01...