[Hackbraten]

Most people can’t breathe at high altitudes due to insufficient air pressure. That’s why airplanes are usually pressurized.

If that extra pressure goes away for whatever reason, people are handed oxygen masks and tanks to help them stay alive. What the GP comment says is that the plane may have been depressurized at one point at high altitude. The pilot’s oxygen mask is usually designed to last longer than any of the other passengers’s masks do. So it’s not entirely implausible that the pilot can still guide the plane into controlled descent, while all the other passengers may have already passed out due to lack of oxygen.

[krisoft]

> Most people can’t breathe at high altitudes due to insufficient air pressure.

Not most people. Nobody can breath if the altitude is high enough. There are some individual variability in how high is too high. That is of interest if you go mountaineering, but not really in a situation where an aircraft rapidly decompresses at the altitude MH370 was speculated to be flying at.

[JumpCrisscross]

> Not most people. Nobody can breath if the altitude is high enough.

Read generously, they're talking about with supplemental oxygen. At 35k feet, even with pure oxygen, many people will not be able to breathe and most will not be able to comfortably. (Above 40k feet, supplemental oxygen no longer works--everybody needs pressurised oxygen.)

(Obviously nobody can breathe above the Armstrong limit, but that isn't relevant with a commercial airliner.)

[nprateem]

I think I saw a YouTube video of a guy in a chamber simulating what happens. Basically you have less than 30s before you enter a state of delirium in which it doesn't seem important to put your mask on, so then you die.

That's why they tell you in safety briefings to always put your own mask on before helping others.