If you've been on a plane-then you've consumed airline coffee. In my opinion, is "horse water".
Think of the quality of water they use for the coffee. It's been in a tank- in the plane's 'belly' for a while.
Most of us avoid drinking free coffee on the plane but then we buy a cup for $5 at the airport.
Here's the catch: The same company that supplies the airport with coffee-usually supplies the the airline your taking today. Conspiracy?
That aside--bottled water is a safe alternative to the "water" the airlines use.
Just avoiding the coffee on the plane is probably the best thing to do.
No quiero cafe de avion.