Grand Canyon National Park is reducing fees for air tour operators that use technology to quiet the sound of aircraft.
The new $20 fee per flight takes effect Jan. 1 for any of eight operators that take visitors to see the massive gorge by air. Operators that don't have quiet technology will continue to pay $25 per flight.
Grand Canyon spokeswoman Maureen Oltrogge says the new fee will save the industry $250,000 a year at full conversion.
The National Park Service and the Federal Aviation Administration had been required to come up with incentives for quiet technology aircraft as part of a law passed in 2012.
Hikers and tourists on the ground have complained that the aircraft noise interferes with the feeling of solitude and appreciation of nature.
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