From a currant thread in the Questions Forum:
Oxygen vs Altitude
My question relates to the emergency oxygen facility of an airliner (or any high altitude pressurised aircraft). My understanding so far, is that as altitude increases, pressure reduces, but the level of oxygen in the air remains the same. Therefore, because of the reduction in pressure, our bodies cannot absorb oxygen very well and thus we can get hypoxia.
So, when the oxygen masks are deployed (in an emergency) with a supply of oxygen, how can this help us to breathe if the outside pressure is still too low? Does it have something to do with the pressure of the oxygen chamber which goes over your mouth?
Thanks pruners,
Maz
But:
If oxygen remains at the same level (20%) as altitude increases then why do I have to lean my piston engine to correct the air fuel ratio? I mean as altitude increases, the engine breathes less air, because it is less dense, and as the carburetor dispenses fuel based upon the mass of airflow, then because the mass flow is lower it will dispense less fuel, automatically correcting the air fuel ratio.
Or am I being very dense myself…
Regards,
White Bear.
Oxygen vs Altitude