Oxygen Systems

[Ewen McPhee]

I am trying to grasp the different oxygen systems available for a/c and would like to ask for help. In light a/c I would assume that one would use a small presurised cylinder and nasal prongs if you were to fly at >10,000 feet for any length of time; given the portability and difficulties installing a permanent system. I am not sure what small commercial a/c do - say a Dash8. In Large commercial a/c I understand that the passengers are supplied with oxygen via a dry chemical exothermic reaction that lasts 12 minutes or so and is activated by pulling down the mask. What I dont know is what the aircrew get. In an emergency do they use pressurised cylinders (e.g. Qantas 747) or a bleed from the compressor a/c system that is stored in a reservoir?

 

Hoping someone can help me

 

 

[facthunter]

OXYGEN systems..

 

The only systems thst I have come across are pressurised medical standard oxy bottles, (other than the chemical ones that you mention, that were more popular overseas) that have to contain an amount dependent on pax numbers. The crew requirements are separate. Portable ones are used as well in larger planes to allow mobility for cabin attendants and crew.

 

I had a Twin Commanche, which came from the states where it had been used to cross over the Rockies regularly, (had turbocharged engines too) and it had a pressurised HP. cylinder, for oxy supply, with a fixed installation.

 

The nasal 2-outlet would NOT do the job for PAX, (unless things have changed) and the crew masks have microphones in them for R/T and intercom and PA (passenger address). The rate of oxygen delivery is adjustable for the crew insomuch as it works on demand. Crew oxygen masks are tested at every crew change. Re your last comment re compressed air, bleed air pressure is quite low. I would doubt that AIR is ever supplied as such. Oxygen diluted with air or at a fixed rate is the way it is done. Nev..

 

 

[Ewen McPhee]

Thanks for that. I have been trying to read around medical issues re. altitude and oxygen use and it gets quite confusing whom is sucking on what.

 

 

[facthunter]

Use of Oxygen.

 

The requirements would be spelled out fully, somewhere (CASR's?) In a practical sense, a fit person would be OK at 12,000'. People who live in a high altitude environment adjust to it and could be OK even at 20,000'.

 

Flight at certain altitudes REQUIRE oxygen to be carried, and at others require it to be USED (where the cabin is not pressurised). The recognition of oxygen deprivation by individuals cannot be relied on unless the individual is well trained to assess the symptoms. Blue colour under the fingernails and a deterioration of handwriting are a couple of indications that are fairly reliable. Older/ or unfit /or smokers can expect to be more affected, and should be more cautious as the effects could be noticed even as low as 5,000'. The CABIN altitude in a fully pressurised aircraft, can be up around 7,000', so you could still suffer effects in a pressurised environment. The normal MAX cabin differential is between 8 & 9 psi.(.6 Bar).

 

What I have written here, is not meant to be any more than an overview. If you want to get across it, get more factual data Nev..

 

 

[Yenn]

Not much good knowing what the signs of hypoxia are. By the time you see them on yourself, you will not care.

 

I have heard that ordinary welding oxygen is OK, but doubt that CASA would approve.

 

I have seen adverts for canula systems in Kitplanes Magazine, but don't have one handy at the moment. maybe try google for oxygen and canula.

 

 

[Guest Andys@coffs]

Gliding clubs deal with this issue all the time. At my club which is mixed gliding ultralight but predominently gliding there is an appointed member who looks after the oxygen systems. My understanding is that they are pressurised bottles and nasal cannulas(sp?). So if you are looking for more info talk to a gliding club.

 

Andy

 

 

[Yenn]

Ewen. I have found a couple of ads which may help.

 

Aerox email [email protected] and Oxygen Systems look at http://WWW.mtn-high.com.

 

 

[Ewen McPhee]

Thanks very much everyone:wave: