This is also an issue for planes landing at the South Pole, where the plateau can have a pressure altitude of up to 12500ft. If you arrive in a Hercules (as opp

This is also an issue for planes landing at the South Pole, where the plateau can have a pressure altitude of up to 12500ft. If you arrive in a Hercules (as opposed to a DC3/Basler which is unpressurised) they have to vent the cabin just before landing.