It is wonderful how perfect a long flight is for preparing a presentation. You are essentially “alone in the crowd” — everybody is in their own world, and you are under no social obligation to talk to anyone.
The physical environment is so unappealing that you have no problem focusing on your computer screen. So it’s just you and your thoughts and your notebook computer, and whatever you need to look up on the internet.
Instead of a long flight being a boring waste of time, the sheer number of hours available for working turns out to be incredibly productive. You just need to remember two things:
(1) Bring some yummy snacks, and (2) Whatever you do, resist the temptation to start watching an in-flight movie.