There are a few "av-geek" videos that cover operations of airlines in the vicinity of the Tibetan plateau, and they talk about how the pilots have to be qualifi

There are a few "av-geek" videos that cover operations of airlines in the vicinity of the Tibetan plateau, and they talk about how the pilots have to be qualified and trained for the fact that the plane is never at an altitude where people breathe easily. Even railroad operations require things like the availability of supplemental oxygen for passengers and crew.