(1) Air tours are flights conducted for sightseeing.
(2) The Sierra Club supports management tools and methods to diminish or eliminate impacts from aircraft tours and landings, including bans of tours and landings wherever and whenever appropriate, on National Monuments and units of the National Park System and the National Wilderness Preservation System.
(3) Agencies should preserve and, where there are impacts, fully restore the natural quiet within protected areas and address this issue in their general management plans.
(a) The Sierra Club believes that, to be the most appropriate and effective, control over air tour use of airspace above such protected areas should rest with the respective land management agencies (e.g., National Park Service, U. S. Forest Service, Bureau of Land Management, U. S. Fish and Wildlife Service). These are the agencies in position to understand these areas most intimately, and which are charged to provide them the fullest possible resource protection.
(b) The managing agency should work with responsible parties to reduce or eliminate air tours or landings outside a protected area if needed to restore natural quiet within the unit. Federal managers of adjoining areas should coordinate their management planning efforts.
(c) The Sierra Club supports the establishment of appropriate noise standards and comprehensive baseline sound-level monitoring and sound-source inventories of all protected areas. This includes continual assessment of noise from all human-generated sources and incorporation of public comments about noise impacts.
Background: Principles of Natural Quiet
(1) The sounds and silences of nature are among the intrinsic elements that combine to form the natural environment. Natural sounds amidst intervals of stillness are inherent components of the "scenery and the natural and historic objects and the wildlife" within National Monuments and units of the National Park System and National Wilderness Preservation System.
(2) Natural quiet is the extended opportunity to experience only natural sounds amid periods of deepest silence. The quiet to be preserved or restored is as defined by the National Park Service as "the quiet at the lower end of the ambient sound level range that occurs regularly between wind gusts, animal sounds, etc., not just the average sound level." As the Park Service explains, "Lulls in the wind or interludes between animal sounds create intervals where the quiet of a sylvan setting is quite striking. In considering natural quiet as a resource, the ability to hear clearly the delicate and quieter intermittent sounds of nature, the ability to experience interludes of extreme quiet for their own sake, and the opportunity to do so for extended periods of time [are] what natural quiet is all about."
(3) Many of these protected areas are vast, open places of astonishing beauty and wildness. Each protected area has a distinct and powerful aura, fully dependent upon the tenuous natural sounds and natural quiet. As such, these areas afford unique opportunities for undistracted respite, solitude, contemplative recreation, inspiration, and education. Further, these units also provide scarce refuge and undisturbed natural habitat for animals. Artificial, human-generated noise can disturb some sensitive animal activities. Therefore, noisy overflights that disturb the peace are not normally appropriate in our protected areas.
Quotations are from National Park Service, U.S. Department of Interior, Report to Congress on Effects of Aircraft Overflights, 1994.
Adopted by the Sierra Club Board of Directors, February 17th, 2001.