that's what a friend of mine has been telling me, he has it. but if i go with xm, since my dad has it we can do this family plan where it would only cost me $7 a month, so i think i'm going to go with that. otherwise i would probably go with sirius.
You probably wouldn't be allowed to use them since it might interfear with the signals the plane is getting... I duuno. My friends dad is a pilot and explained it to me, but I still don't understand it.