Your first post in this regard was what prompted me to ask the question. Here is your first post:
You don't mention a thing about watching movies on flights, Fair use ... etc ... You mention making a backup or copy. If people are allowed to make copies, then companies are going to lose the profit motive for producing a disc.
And the rules about DVD's are quite clear when you purchase them. You don't have to make the purchase. Therefore, you have complete liberty from Big Business.
As for your flight, take your laptop computer. They are excellent for watching movies.