Being polite to your flight attendant is definitely an appreciated behavior. Think, how would you feel if you were running from flight to flight without many naps and had to ensure the safety and comfort of hundreds of passengers every day.

Wonders List
Making a good impression on a flight attendant can make an impact when it comes to getting in the running for a better seat. That being said, rude or unruly behavior could land you a spot smack dab in the middle of a bunch of babies and children. Hint: these little people cry…A LOT!
16. How Clean is the Water?
As a rule thumb, you should NEVER drink water from the lavatory tap on airplanes. But the potable water used in coffee and tea is safe to stomach, right? Well…according to the account of many flight attendants, it sounds like it’s best to stick to the bottled beverages and get your caffeine fix on the ground.

Evening Standard
Although the tanks for those drinks are cleaned, there still remains the question of how often those custodial tasks are performed. Apparently, the answer is not as often as you would think, and the valve for cleaning lavatory waste is pretty close to the one for filling clean water. That’s a bummer for those long, international trips.