We're going on a trip soon (to Florida, and hey, I think we'll do a Florida writers post soon, too), and I'm trying to think of good books that involve flying. I'm sweet on the subject anyway, as my first book was about a plane crash (I feel funny even typing that here), and one of my early stories took place in a succession of airports. The book that sprung immediately to mind was Walter Kirn's Up In The Air, which I liked a lot. I don't love Kirn's stuff, but he's one of those writers about whom I always think his next one is gonna be great. His fiction feels unrealized but full of terrific ideas. Anyway, Up In The Air is about a borderline-insane management consultant whose life goal is to rack up a million frequent flyer miles. It's a twisted little quest novel with an ending I remember as half spectacular, half disappointing...but the fun in it is Kirn's observations of hecticness and its consequences. Definitely a good airport read.
The most memorable plane story, for me, is Stephen King's "The Langoliers," from his novella collection Four Past Midnight. I believe this story was turned into a TV series, which I haven't seen. Anyway, it's about a blind girl who goes to the rest room on an airplane, and when she emerges everyone else on the plane is gone. Great setup, and I am sure that somebody on the Lost writing team read when they were a teenager. Like a lot of King, I don't recall it ever really living up to its promise, but the concept was more than enough for it to stick with me.
If you've got a good one in mind, post it in the comments!