It is impossible, i do not know why are you asking this kind of questions to be honest.
Take a second, and think about it, all the airports have thousands of methods to control and take care of who is taking a plane, or who is entering the airport, and how they pay for the tickets.
With bitcoin, it would be almost impossible to do that.
How sweet could it be?
I really want the professionals to shed more light on this if it could be actualized and how easier could it be and what implication can it have on bitcoin