>>16884470Actually, it's much more boring than that. Planes don't even use magnetic compasses - they use gyroscopic compasses instead, which are much more accurate because they don't use the magnetic field.
Remember, the North and South magnetic poles don't actually line up very well with the North and South geographic poles, so you need a second map of the magnetic field to get accurate directions with a compass over long distances.
The actual reason is ETOPS legislation: twin-engine aircraft aren't allowed to fly more than a particular one-engine flight time from the nearest airport, to ensure that if one engine burns out the plane can make it back safely.
Because there aren't exactly a lot of international airports around Antarctica and the North Pole, this means that the poles are basically a no-fly zone.
Now, aircraft with more than two engines can still legally fly over Antarctica, and indeed commercial sightseeing flyovers were once commonplace- but after the crash of New Zealand Flight 901, those virtually vanished.
