The proposal raises height limits for aircraft flying over the area, suggests no-fly zones and calls for phasing in quieter aircraft.
Air tours currently carry about 400,000 passengers annually over the canyon. And while "they play an important role in visitor enjoyment … without more thoughtful management, air-tour flights can interfere with the enjoyment of visitors on the ground," the park service said in a statement. (Photo by Lenny Konieczski)
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