Oxygen in cabins
 

Hey,

one more:-) : I know that we're regulating the pressure and the oxygenflow of a cabin. but where does the cabin get the oxygen for a flight for about 12 hours in 39000 feet?
how big are the reserves and tanks?

Thanks!

OD

we\'ll sorry for the stupid question, i got it myself. the quantity of oxygen remains the same in the atmosphere with 21%. now it depends on the partial pressure, and this partial pressure decreases with altitude and thats why why we pressurize the cabin, is that right?:ok:

pretty much! :ok:
the air is bled off the engine compressor (before it enters the combustion chamber :} ) and is then cooled through precoolers and air conditioning packs before entering the cabin.
Oxygen is used directly from cylinders in emergency situations only.

... which means you could in theory stay up there until there's no fuel left and the engines stop (not a very good idea)!!!