Three altimeters in the cockpit — two bright digital readouts, and one old-school device with hands that turn like those of a clock — show 31,000 feet. Yet we know that we are probably not as close to 31,000 feet as these altimeters suggest. We are somewhat lower; or perhaps we are higher. One thing is certain — it would be easy to find a dozen airliners flying over different parts of the world, all of whose altimeters displayed 31,000 feet, none of which are at the same altitude.
Een vlucht van London naar Tokio bekeken en geschreven door piloot Mark Vanhoenacker voor NYTimes.com. Zeer lezenswaardig stukje voor iedereen die ooit piloot wilde worden.