I certainly wouldn't trust it. I am sure when it is loaded on the aircraft into the potable tank it is safe, however, I worry about the cleanliness of the tank itself, the lines, and most commonly, the actual faucet. And of course, the lines and tanks on the truck that brought the water. Planes are not deep cleaned that often vs how often they fly and I don't even know if they clean the faucet when they disinfect the tank and lines. Lines and faucets are frequently the cause of bacterial food poisoning yet almost never thought of. People go to a movie theater or fast food place, eat, get diarrhea a short while later and assume it was the food. But if you drank something from a line like a soda or beer..or used ice from the ice machine, odds are THAT was what made you sick, not the cooked food. Stick with the bottled stuff.