Since 1987, the Park Service has been trying to cut down on noise from sightseeing flights over Grand Canyon and other parks, which drowns out subtle natural sounds like wind, birdsong and crickets. In 1996, President Clinton ordered an immediate reduction of air tours in the Grand Canyon. But tour operators protested vigorously, and the restrictions were watered down. Today, the agency says that some parts of the park are filled with the drone of aircraft “virtually 100 percent” of the day.
The Park Service's new plan would create "natural quiet" in 67 to 77 percent of the Grand Canyon for at least three-quarters of each day. The agency’s preferred alternative would create no-fly zones in some areas, phase in quieter aircraft, require them to fly at higher elevations, reduce total flight-seeing tours per year by about 30 percent, and prohibit flights an hour after sunrise and before sunset. Public comment on the plan is open through June 6.