摘要: Special Federal Aviation Regulation (SFAR) 50-2 established flight-free zones andrelated measures for the purpose of mitigating aircraft noise impacts on Grand Canyon National Park. Public Law 100-91 imposes on the National Park S... 展开 Special Federal Aviation Regulation (SFAR) 50-2 established flight-free zones andrelated measures for the purpose of mitigating aircraft noise impacts on Grand Canyon National Park. Public Law 100-91 imposes on the National Park Service the responsibility for determining (among other things) whether SFAR 50-2 has succeeded in substantially restoring the natural quiet in Grand Canyon National Park. This report describes efforts undertaken: (1) to determine the extent to which natural quiet has been restored in Grand Canyon National Park following implementation of SFAR 50-2; (2) to determine the utility of customary noise exposure prediction methods for evaluating the effectiveness of SFAR 50-2 in restoring natural quiet in Grand Canyon National Park; and (3) to create a graphic representation of the impacts of air tour flight operations on the natural quiet of Grand Canyon National Park. 收起