During the run-up to the 2008 presidential election, Senator John McCain of Arizona was applauded by many as a friend of the national parks.

However, some groups are now wondering why the senator is supporting legislation that would increase air tours over Grand Canyon National Park, an experience that offers many incredible views of the park and yet one that others criticize for the noisy intrusion on the park setting.

According to the National Parks Conservation Association, Senators McCain and Jon Kyl of Arizona, supported by Senators Harry Reid and John Ensign of Nevada, have introduced an amendment to the Federal Aviation Administration Reauthorization Bill that would allow for more air tours and “aircraft noise” at the Grand Canyon than currently allowed.

Passage of the amendment, which could come up for a vote as early as today, “would undercut the years of work through a public process to develop regulations for air tours that would better ensure quiet in the park while still providing opportunities for people to view the park by air,” NPCA officials said. “And, as the first park air tour plan, it would set a bad precedent for other national parks that are also affected by air tour noise.”

According to the parks advocacy group, the amendment:

* Prohibits any reduction in the allocation of air tours over the park – even if they disrupt visitors who are enjoying the park from the rim, river, or hiking trails, and requires a rule-making to assess possible increases in the number of daily air tours.

* States that “substantial restoration of natural quiet” has occurred when 50 percent of the park is “quiet” for at least 75 percent of the time. That prevents the NPS from improving current conditions, and means half the park will virtually never be free of air tour noise that disrupts the experience of park visitors.

* Establishes a definition of natural quiet that ignores noise from other aviation sources (such as flights that are not intended for sight-seeing).

The amendment also would allow 364 overflight tours per day.

While the amendment calls for overflight tour planes to be converted to “quiet aircraft technology,” it also provides 15 years from enactment of the amendment for those conversions to be made. Companies that make the conversions before then will be eligible for reducing overflight fees and more flights, the amendment adds.

Compared to those provisions, the NPCA points out that the National Parks Overflights Act of 1987 calls for the “substantial restoration of natural quiet” at Grand Canyon National Park.

The NPS and FAA have completed an environmental impact study that is very close to release by the Department of Interior, according to NPCA. The study reflects years of hard work and input from local stakeholders and the American public and includes a range of alternatives.