Guy starts dozing off on a red-eye flight on a small plane. He feels everyone looking at him. Wakes up, no one is looking, starts dozing off again. The feeling returns. Slight feeling of panic, can't sleep. Watches the movie. It sucks. Eventually he dozes off and finds hands on his throat, or teeth in his face, or whatever.

He discovers all (or some?) of the other passengers were vampires or ghouls or something. They feed on other passengers on planes, jump out, and crash the plane. The pilots are part of it.

The idea came to me on a plane. (I fly a lot.) I can't write mysteries or horror, so if anyone wants to run with it, feel free.