Why do you have to be 3-4k above the rim when you do the Grand Canyon?

Noise Nazis have made it illegal to go beneath the canyon rim.
Additionally, you must fly a very strictly defined course over the
canyon, from one GPS coordinate to another. Course variances will
land you in hot water with...someone.

I'd love to fly down the canyon with the helicopters, like flying down
the Hudson with them whenever I do the NYC tour.

Even the tour helicopters can't go down in the canyon anymore. It's
very sad, IMHO, as many thousands of people have had their Grand
Canyon experience drastically diminished so that a far smaller number
of people can quietly hike into it.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"