11. Don’t drink water on a plane that didn’t come from a bottle.
Former Lufthansa cargo agent here.
Do not EVER drink water on an aircraft that did not come from a bottle. Don’t even TOUCH IT. The reason being the ports to purge lavatory shit and refill the aircraft with potable water are within feet from each other and sometimes serviced all at once by the same guy. Not always, but if you’re not on the ramp watching, you’ll never know.