O2 Mask On Pilot?

[fred]

At some point in time I remember hearing that above a certain altitude the
pilot or co-pilot must be wearing an O2 mask on commercial flights. Am I
right? Details?

[Bob Gardner]

91.211

Bob Gardner

"fred" > wrote in message
...
> At some point in time I remember hearing that above a certain altitude the
> pilot or co-pilot must be wearing an O2 mask on commercial flights. Am I
> right? Details?
>

[fred]

"Bob Gardner" > wrote in message
...
> 91.211


So what the devil is "91.211"?

> Bob Gardner
>
> "fred" > wrote in message
> ...
>> At some point in time I remember hearing that above a certain altitude
>> the pilot or co-pilot must be wearing an O2 mask on commercial flights.
>> Am I right? Details?
>>
>
>

[Steven P. McNicoll]

"fred" > wrote in message
...
>
> So what the devil is "91.211"?
>

FAR 91.211, applicable to the US.


§ 91.211 Supplemental oxygen.

(a) General. No person may operate a civil aircraft of U.S. registry-

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including
14,000 feet (MSL) unless the required minimum flight crew is provided with
and uses supplemental oxygen for that part of the flight at those altitudes
that is of more than 30 minutes duration;

(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required
minimum flight crew is provided with and uses supplemental oxygen during the
entire flight time at those altitudes; and

(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant
of the aircraft is provided with supplemental oxygen.

(b) Pressurized cabin aircraft. (1) No person may operate a civil aircraft
of U.S. registry with a pressurized cabin-

(i) At flight altitudes above flight level 250 unless at least a 10-minute
supply of supplemental oxygen, in addition to any oxygen required to satisfy
paragraph (a) of this section, is available for each occupant of the
aircraft for use in the event that a descent is necessitated by loss of
cabin pressurization; and

(ii) At flight altitudes above flight level 350 unless one pilot at the
controls of the airplane is wearing and using an oxygen mask that is secured
and sealed and that either supplies oxygen at all times or automatically
supplies oxygen whenever the cabin pressure altitude of the airplane exceeds
14,000 feet (MSL), except that the one pilot need not wear and use an oxygen
mask while at or below flight level 410 if there are two pilots at the
controls and each pilot has a quick-donning type of oxygen mask that can be
placed on the face with one hand from the ready position within 5 seconds,
supplying oxygen and properly secured and sealed.

(2) Notwithstanding paragraph (b)(1)(ii) of this section, if for any reason
at any time it is necessary for one pilot to leave the controls of the
aircraft when operating at flight altitudes above flight level 350, the
remaining pilot at the controls shall put on and use an oxygen mask until
the other pilot has returned to that crewmember's station.

[Happy Dog]

"fred" > wrote in message news:Tk8Me.
>
> "Bob Gardner" > wrote in message
> ...
>> 91.211
>
>
> So what the devil is "91.211"?

So what the devil is Google?

+oxygen +"91.211" 480 Hits.

moo

[Dave S]

Steven P. McNicoll wrote:

>
> (ii) At flight altitudes above flight level 350 unless one pilot at the
> controls of the airplane is wearing and using an oxygen mask that is secured
> and sealed and that either supplies oxygen at all times or automatically
> supplies oxygen whenever the cabin pressure altitude of the airplane exceeds
> 14,000 feet (MSL), except that the one pilot need not wear and use an oxygen
> mask while at or below flight level 410 if there are two pilots at the
> controls and each pilot has a quick-donning type of oxygen mask that can be
> placed on the face with one hand from the ready position within 5 seconds,
> supplying oxygen and properly secured and sealed.
>
>

I flew on an air ambulance Lear 25 for a while.. and I can say I NEVER
saw the cockpit crew remove the masks from the hangars and place them in
"the ready position" even though we routinely went to FL 450-490. I am
wondering how many operators follow this rule.

Dave

[Bob Moore]

"Steven P. McNicoll" > wrote
> (ii) At flight altitudes above flight level 350 unless one pilot at
> the controls of the airplane is wearing and using an oxygen mask that
> is secured and sealed and that either supplies oxygen at all times or
> automatically supplies oxygen whenever the cabin pressure altitude of
> the airplane exceeds 14,000 feet (MSL), except that the one pilot need
> not wear and use an oxygen mask while at or below flight level 410 if
> there are two pilots at the controls and each pilot has a
> quick-donning type of oxygen mask that can be placed on the face with
> one hand from the ready position within 5 seconds, supplying oxygen
> and properly secured and sealed.

The Part 121 requirement for Certificated Aircarriers is more restrictive
than for Part 91 Operators. The FL350 is replaced with FL 250.

Bob Moore

[Sylvain]

fred wrote:

> So what the devil is "91.211"?

14 CFR 91.211

http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=5eea221bb5168bdef3b9f5c34c114e4e&rgn=div5&view=text&node=14:2.0.1.3.10&idno=14#14:2.0.1.3.10.3.7.6

--Sylvain

[Steven P. McNicoll]

"Bob Moore" > wrote in message
21...
>
> The Part 121 requirement for Certificated Aircarriers is more restrictive
> than for Part 91 Operators. The FL350 is replaced with FL 250.
>

But still not applicable to the Greek 737 that went down yesterday, although
a similar requirement may have existed for them.

[GeorgeB]

On Mon, 15 Aug 2005 23:37:07 GMT, "Steven P. McNicoll"
> wrote:

>"Bob Moore" > wrote in message
21...
>>
>> The Part 121 requirement for Certificated Aircarriers is more restrictive
>> than for Part 91 Operators. The FL350 is replaced with FL 250.
>
>But still not applicable to the Greek 737 that went down yesterday, although
>a similar requirement may have existed for them.

What would have been the effect if the O2 bottle for the cockpit had
been inadvertently filled with breathing air rather than O2? I seem
to remember that this was discovered to have happened somewhere in the
US in the last few months? I would think that a casual test would
have found it normal, but that the PPO2 would have been substantially
too low even with a pressurized mask?

[Stefan]

GeorgeB wrote:

> What would have been the effect if the O2 bottle for the cockpit had
> been inadvertently filled with breathing air rather than O2?

They would have tested the system before the flight and found it
working. They would have put on their mask in flight and thought it
worked, slowly fading away without recognizing it. You may or may not
recognize hypoxia when you suspect it and really watch your body, you
definitely don't recognize it when you're unwary.

Stefan

[fred]

"Stefan" > wrote in message
...
> GeorgeB wrote:
>
>> What would have been the effect if the O2 bottle for the cockpit had
>> been inadvertently filled with breathing air rather than O2?
>
> They would have tested the system before the flight and found it working.
> They would have put on their mask in flight and thought it worked, slowly
> fading away without recognizing it. You may or may not recognize hypoxia
> when you suspect it and really watch your body, you definitely don't
> recognize it when you're unwary.


The question was what happens when breathing air from the mask rather than
O2 and the answer is nothing at all at a cabin pressure of 10K feet.

[Stefan]

fred wrote:

> The question was what happens when breathing air from the mask rather than
> O2 and the answer is nothing at all at a cabin pressure of 10K feet.

Got me :-). On the other hand, if the bottels were filled with say N2
instead of O2, they would still have faded away even at 10 kft. Further
speculations?

Stefan

[fred]

"Stefan" > wrote in message
...
> fred wrote:
>
>> The question was what happens when breathing air from the mask rather
>> than O2 and the answer is nothing at all at a cabin pressure of 10K feet.
>
> Got me :-). On the other hand, if the bottels were filled with say N2
> instead of O2, they would still have faded away even at 10 kft. Further
> speculations?

Yes and pure N2 is faster than air at 35,000.

[Edwin Johnson]

On 2005-08-15, Dave S > wrote:
>
> I flew on an air ambulance Lear 25 for a while.. and I can say I NEVER
> saw the cockpit crew remove the masks from the hangars and place them in
> "the ready position" even though we routinely went to FL 450-490. I am

On our 25D the position of the hangers for the masks were considered in the
'ready' position, so you just made sure they were there. Believe it was a
5-sec operation (required time) to get them on your head, for the
quick-doning masks.

The old joke, before the quick-doning type masks, was that the Learjet
pilots always squeezed their noses before de-boarding to make it look like
they had been wearing their masks.

....Edwin
--
__________________________________________________ _____
"Once you have flown, you will walk the earth with your
eyes turned skyward, for there you have been, there you
long to return."-- da Vinci ... www.shreve.net/~elj

[George Patterson]

fred wrote:
>
> The question was what happens when breathing air from the mask rather than
> O2 and the answer is nothing at all at a cabin pressure of 10K feet.

But the question was asked about pilots that were at 35,000'. I believe that
George B. is correct that the partial pressure would be too low and the pilots
would pass out.

George Patterson
Give a person a fish and you feed him for a day; teach a person to
use the Internet and he won't bother you for weeks.

[Steven P. McNicoll]

"GeorgeB" > wrote in message
...
>
> What would have been the effect if the O2 bottle for the cockpit had
> been inadvertently filled with breathing air rather than O2?
>

From what would the oxygen system be serviced in your scenario? A
compressor?

[GeorgeB]

On Thu, 18 Aug 2005 18:50:06 GMT, "Steven P. McNicoll"
> wrote:

>
>"GeorgeB" > wrote in message
...
>>
>> What would have been the effect if the O2 bottle for the cockpit had
>> been inadvertently filled with breathing air rather than O2?
>>
>
>From what would the oxygen system be serviced in your scenario? A
>compressor?

I've far more experience with industrial compressed gasses than with
aircraft oxygen, and see much more "compressed breathing air" than
BREATHING compressed O2. (Oxygen for oxyacetelyne is to different
standards, but I think it is just as good; several college buddies
would spend some time breathing it after having too much to drink the
night before. Ah, the REAL hangover cure.

Firefighters and scuba divers use it in large quantiies. Bottles are
common with gas suppliers. What I don't know is how the fittings
compare.

Nor do I know how a plane's bottles are filled; via compressor from
low pressure sources, high pressure via cascade bottles, or ???

I do know that the fittings need to be clean of oxydizable materials;
storoes of a little oil on gauge threads, if true, keep one careful.

[Happy Dog]

"GeorgeB" > wrote in

> I've far more experience with industrial compressed gasses than with
> aircraft oxygen, and see much more "compressed breathing air" than
> BREATHING compressed O2. (Oxygen for oxyacetelyne is to different
> standards, but I think it is just as good;

Correct. It's just as good now.

moo

[Steven P. McNicoll]

"GeorgeB" > wrote in message
...
>
> I've far more experience with industrial compressed gasses than with
> aircraft oxygen, and see much more "compressed breathing air" than
> BREATHING compressed O2. (Oxygen for oxyacetelyne is to different
> standards, but I think it is just as good; several college buddies
> would spend some time breathing it after having too much to drink the
> night before. Ah, the REAL hangover cure.
>
> Firefighters and scuba divers use it in large quantiies. Bottles are
> common with gas suppliers. What I don't know is how the fittings
> compare.
>
> Nor do I know how a plane's bottles are filled; via compressor from
> low pressure sources, high pressure via cascade bottles, or ???
>
> I do know that the fittings need to be clean of oxydizable materials;
> storoes of a little oil on gauge threads, if true, keep one careful.
>

In a previous life I was in aircraft maintenance. Aviator's breathing
oxygen systems were serviced from just two sources; compressed oxygen
bottles or liquid oxygen carts. The only other compressed gas bottle used
for servicing aircraft was nitrogen. I don't recall what measures were
taken to prevent servicing oxygen systems with nitrogen, other than colors
and markings on the bottles, but servicing oxygen systems with nitrogen
would be a very bad thing.

[Jose]

> servicing oxygen systems with nitrogen
> would be a very bad thing.

What would it feel like to breathe nitrogen instead of oxygen or air? I
presume one would just get euphoric, pass out, and die, with nary a clue.

Jose
--
Quantum Mechanics is like this: God =does= play dice with the universe,
except there's no God, and there's no dice. And maybe there's no universe.
for Email, make the obvious change in the address.

[Happy Dog]

"Jose" > wrote in message
>> servicing oxygen systems with nitrogen would be a very bad thing.
>
> What would it feel like to breathe nitrogen instead of oxygen or air? I
> presume one would just get euphoric, pass out, and die, with nary a clue.

Yep. No buildup of CO2. Everything would feel just fine. Just a bit of
warning dizziness.

moo

[Happy Dog]

"Steven P. McNicoll" > wrote in message
> In a previous life I was in aircraft maintenance. Aviator's breathing
> oxygen systems were serviced from just two sources; compressed oxygen
> bottles or liquid oxygen carts. The only other compressed gas bottle used
> for servicing aircraft was nitrogen. I don't recall what measures were
> taken to prevent servicing oxygen systems with nitrogen, other than colors
> and markings on the bottles, but servicing oxygen systems with nitrogen
> would be a very bad thing.
Different fittings.

moo

[JJS]

"Jose" > wrote in message ...
>> servicing oxygen systems with nitrogen would be a very bad thing.
>
> What would it feel like to breathe nitrogen instead of oxygen or air? I presume one would just get euphoric, pass
> out, and die, with nary a clue.
>
> Jose

Years ago we had a contract laborer working in a catalyst vessel with a nitrogen atmosphere. He lifted his breathing
air mask to spit. Bad move. Sucked in a breath and it was nearly his last. The man passed out and started
convulsing. The confined space attendant radioed for help from the ERT. Ever tried to pull a convulsing patient
from a manway? Even with a tripod / winch / cable / harness already rigged, it was quite a job. The man lived but
was hospitalized for quite awhile. A co-worker put on an airmask that inadvertently been connected to a nitrogen
header. This was back in the 60's. He took one breath and woke up in the hospital. Thankfully, he didn't have a
chance to fully strap the mask on.



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[Ash Wyllie]

Jose opined

>> servicing oxygen systems with nitrogen
>> would be a very bad thing.

>What would it feel like to breathe nitrogen instead of oxygen or air? I
>presume one would just get euphoric, pass out, and die, with nary a clue.

Skip the euphoria, and you have your answer.


-ash
Cthulhu in 2005!
Why wait for nature?

[Jose]

>>What would it feel like to breathe nitrogen instead of oxygen or air? I
>>presume one would just get euphoric, pass out, and die, with nary a clue.
>
>
> Skip the euphoria, and you have your answer.

Ok, then what causes the euphoria which is supposed to be part of
hypoxia, and why doesn't it apply here?

Jose
--
Quantum Mechanics is like this: God =does= play dice with the universe,
except there's no God, and there's no dice. And maybe there's no universe.
for Email, make the obvious change in the address.

[Ash Wyllie]

Jose opined

>>>What would it feel like to breathe nitrogen instead of oxygen or air? I
>>>presume one would just get euphoric, pass out, and die, with nary a clue.
>>
>>
>> Skip the euphoria, and you have your answer.

>Ok, then what causes the euphoria which is supposed to be part of
>hypoxia, and why doesn't it apply here?

A pure N2 atmosphere has no O2. So unconsciousness occurs quickly, and
unexpectedly, leaving no time for euphoria.

It is not quit as fast as decompressioin, but fast with no warning. Scroll
down http://www.cfht.hawaii.edu/~warren/safety/CryogenicLiquids.htm for
example.


-ash
Cthulhu in 2005!
Why wait for nature?