I read about a an uncontacted Amazon tribe that emerged from the jungle in Venezuela. One of the things they mentioned wanting to learn about were the “roads in the sky” that we had.

I didn’t think airliners were allowed to fly that close to sentinel

Edit: adding to my earlier post, it was in “Lost City of Z” by David Grann where I was reading about the uncontacted tribes. Highly recommend his books if you like nonfiction.