GLOBAL: Imagine for just a moment an airport where flight crews are required to use supplemental oxygen upon arrival. A place where you may see the pilots of your flight on the flight deck wearing oxygen masks while parked at the gate with engines off. La Paz Airport in Bolivia is one such place. It’s considered a very high-altitude airport where you could easily pass out if you are not well acclimated to the thin air. Remember that most commercial airliners today are designed to maintain a comfortable internal cabin altitude of around 7000 feet. This is even though the aircraft is flying at 35,000 feet, for example.