It's interesting that most of the panic attacks people have had were during boarding or sitting on the runway. I had my first ever panic attack on a mainline plane, DEN-HNL, while were were about halfway between the West Coast and Hawaii. I had been op-upped to F, and put in a window seat, when I always, always book aisles to avoid any claustrophobia. I considered asking for my original E+ aisle seat back, but thought I could handle it and was excited about sitting in F. We were about 2.5 hours from any sort of land when I started panicking, and had to dig my fingernails into my palms to keep from jumping out of my seat and screaming, "Let me off this plane right now!!" (Which would have been impossible anyway given where we were at the time). It was a horrifying experience, and one I hope to never experience again. I have heard good things about a low dose of Xanax, but of course, like others have said, it's best to consult your doctor on that one.