It's a common problem that all airline crews face, but most often in the premium cabins where the booze is comped. Very seldom do we encounter the passenger that drinks to excess in the economy cabin unless they have brought their own, a violation of FAR's.

We have a little game we play in the "upgrade" cabins where, without referring to the paperwork, we guess the upgraded passengers, and the "real" paying folks. The standard we use, that is far more accurate than you would think, is observing alcoholic intake. There is a strong propensity for upgrades to knock back a few pre-dinner pops, then guzzle wine as if they were 18 again, as many apertifs as time permits, and then keep drinking until they are cut off or pass out.

What is amazing, is that these are people that hold responsible positions, and should be smart enough to understand that water and juice are the only beverages one should drink at all when flying. Having said that I know that scenerio is unrealistic. On the other hand the real pro's are the premium passengers who (international flights) get on, refuse the food, ask for water, and go to sleep immediately after take off. They understand what is important. I realize there are exceptions, but believe me when I say that my comments are more rule than exception.