O2 and Cypriot airliner crash

[[email protected]]

In accounts of the crash of the Cypriot airliner in Greece, all I've
read say that loss of cabin pressure could not, by itself, incapacitate
the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
this plane was at 35k) O2 supply by itself will not suffice to keep you
conscious and that the drop down masks only give a false sense of
security. He said that the ambient pressure is so low that even 100% O2
does not provide enough to keep you conscious without a pressure
breathing mask. If he's right, that could explain the crash, especially
given that all it would take is 20 seconds of distraction (i.e., not
donning the mask) to knock out the pilot as indicated in the table
below. On the other hand, I checked and a standard atmosphere at 35k
feet is 7.0 in of Hg, which is more than the partial pressure of O2 at
sea level (6 in = 20% of 30 inches), which would seem to contradict the
info given by the ATP. Any thoughts or corrections to my reasoning?


Tlme of useful
consciousness
Altitude (ft) without oxygen

40,000 15 seconds
35.000 20 seconds
30,000 30 seconds
28,000 1 minute
26,000 2 minutes
24,000 3 minutes
22,000 6 minutes
20,000 10 minutes
15.000 Indefinite

[Bucky]

wrote:
> 40,000 15 seconds
> 35.000 20 seconds
> 30,000 30 seconds

I don't get it. Can't a person stay conscious for longer than 30
seconds without breathing? Most people can hold their breath for over
a minute.

[Brien K. Meehan]

The "partial pressure of O2" has nothing to do with it.

Your premise is wrong. Loss of cabin pressure IS what incapacitates
pilots. The lungs need atmospheric pressure to exchange gasses with
hemoglobin in the alveoli. It doesn't matter what gas it is - without
the pressure, respiration stops happening. As altitude increases and
pressure decreases, respiration becomes less effective. Below a
certain pressure, you can suffocate on 100% oxygen.

[Bruce Hoult]

In article . com>,
wrote:

> In accounts of the crash of the Cypriot airliner in Greece, all I've
> read say that loss of cabin pressure could not, by itself, incapacitate
> the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
> this plane was at 35k) O2 supply by itself will not suffice to keep you
> conscious and that the drop down masks only give a false sense of
> security. He said that the ambient pressure is so low that even 100% O2
> does not provide enough to keep you conscious without a pressure
> breathing mask.

I personally know glider pilots here in New Zealand who have flown to
betweeen 35,000 and 37,000 ft with only an ordinary oxygen mask, not a
pressure system.

The glider world record of 49,000 ft used a pressure system.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[Peter Duniho]

"Bucky" > wrote in message
oups.com...
> I don't get it. Can't a person stay conscious for longer than 30
> seconds without breathing? Most people can hold their breath for over
> a minute.

When they do that, they are using up a small reserve of oxygen-filled air
contained in their lungs. Exhale as much air from your lungs as you can,
and THEN see how long you can hold your breath.

[Stefan]

Peter Duniho wrote:

> When they do that, they are using up a small reserve of oxygen-filled air
> contained in their lungs. Exhale as much air from your lungs as you can,
> and THEN see how long you can hold your breath.

Even then, there's still a lot of oxygen in the lungs, the human lung is
pretty inefficient. What happens at altitude is that you don't feel the
absence of oxygen, hence just continue to breath normally. This empties
your oxygen reserves rather quickly.

On airliners, though, there are instruments which alarm the pilot of
pressure loss and drop the mask immediately. So there must have been
another problem.

Stefan

[Happy Dog]

"Peter Duniho" > wrote in message
> "Bucky" > wrote in message
> oups.com...
>> I don't get it. Can't a person stay conscious for longer than 30
>> seconds without breathing? Most people can hold their breath for over
>> a minute.
>
> When they do that, they are using up a small reserve of oxygen-filled air
> contained in their lungs. Exhale as much air from your lungs as you can,
> and THEN see how long you can hold your breath.

Partially crap. Learn how lungs work.

moo

[Happy Dog]

"Bruce Hoult" > wrote in message news:bruce-566936.
> wrote:
>
>> In accounts of the crash of the Cypriot airliner in Greece, all I've
>> read say that loss of cabin pressure could not, by itself, incapacitate
>> the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
>> this plane was at 35k) O2 supply by itself will not suffice to keep you
>> conscious and that the drop down masks only give a false sense of
>> security. He said that the ambient pressure is so low that even 100% O2
>> does not provide enough to keep you conscious without a pressure
>> breathing mask.
>
> I personally know glider pilots here in New Zealand who have flown to
> betweeen 35,000 and 37,000 ft with only an ordinary oxygen mask, not a
> pressure system.

It's OK at 34,000 ft and above 38,000 ft. And all other altitudes,
partialy. You were asleep or missed this class, right?

moo

[Ash Wyllie]

Brien K. Meehan opined

>The "partial pressure of O2" has nothing to do with it.

>Your premise is wrong. Loss of cabin pressure IS what incapacitates
>pilots. The lungs need atmospheric pressure to exchange gasses with
>hemoglobin in the alveoli. It doesn't matter what gas it is - without
>the pressure, respiration stops happening. As altitude increases and
>pressure decreases, respiration becomes less effective. Below a
>certain pressure, you can suffocate on 100% oxygen.

Seems to me that astronauts use 3psi of pure O2 during EVAs.


-ash
Cthulhu in 2005!
Why wait for nature?

[John Kirksey]

> Tlme of useful
> consciousness
> Altitude (ft) without oxygen
>
> 40,000 15 seconds
> 35.000 20 seconds
> 30,000 30 seconds
> 28,000 1 minute


How, then, can someone like Ed Viesturs repeatedly climb the tallest
mountain peaks in the world without supplemental oxygen? Is it because of
the slower ascent and the time spent acclimating to the higher altitudes?

John K.

[Stefan]

John Kirksey wrote:

> How, then, can someone like Ed Viesturs repeatedly climb the tallest
> mountain peaks in the world without supplemental oxygen? Is it because of
> the slower ascent and the time spent acclimating to the higher altitudes?

First, acclimatisation.

Second, walking (and climbing) is different from flying. You don't need
much brain to walk. When piloting, however, everything is about
thinking. And it's the brain which needs the most oxygen.

And maybe a third reason: There are exceptional people who are just
better suited for such things than you and me.

Stefan

[Mike Rapoport]

Partially because he is acclimated and partly because he is Ed Visteurs.

Mike
MU-2


"John Kirksey" > wrote in message
news:cZ0Me.4596$H_4.4209@trnddc07...
>> Tlme of useful
>> consciousness
>> Altitude (ft) without oxygen
>>
>> 40,000 15 seconds
>> 35.000 20 seconds
>> 30,000 30 seconds
>> 28,000 1 minute
>
>
> How, then, can someone like Ed Viesturs repeatedly climb the tallest
> mountain peaks in the world without supplemental oxygen? Is it because of
> the slower ascent and the time spent acclimating to the higher altitudes?
>
> John K.
>
>
>
>

[Bob Moore]

wrote

> In accounts of the crash of the Cypriot airliner in Greece,

My thoughts on yesterday's accident.

The way the regulations require that it be done.

First........During the preflight, someone ensures that the emergency
oxygen bottles in the lower cargo holds have their valves opened and are
ready for use.

Second...During the cockpit preflight, each pilot tests his oxygen mask
for proper operation and for pressure delivery of oxygen.

Then.......With the engines running and before takeoff, the air
conditioning and pressurization system is turned on (pack valves opened)
and the cruising altitude set in the controller by a crewmember and
verified by the checklist.

The system then functions normally, maintaining a cabin pressure of about
8,000 feet until starting descent.

However if something goes wrong and the cabin altitude rises
uncontrollably............

First.......At 10,000'cabin altitude, A VERY loud warning sounds to alert
the crew. If at cruise altitude, this MANDATES first, immediate donning
of the pilot's oxygen mask followed immediately by an emergency descent
to 14,000'.

Second.. At 13,000' cabin altitude, the outflow valves automatically
close in an attempt to maintain cabin pressure if the system has been
properly turned-on before takeoff. If the system was not properly
turned-on before takeoff, the warning should have occurred during climb.

Third.....At 14,000' cabin altitude, the passenger oxygen masks
automatically drop.

All of these systems are independent. News reports indicate that the
passenger O2 masks did deploy. If so....

Did the warning sound? If it did why was there no emergency descent?
Why was pressure not maintained when the outflow valves closed? Perhaps
the pack valves were not opened before takeoff? Had the pilots O2 bottle
been replaced and the valve not opened or checked during preflight?

Looks like a lot of human error to me. Just speculating. :)

Bob

[pbc76049]

Most passenger O2 systems use chemically generated O2.
There are no bottles to check. There are cabin walk around bottles
and the flight deck is bottled O2, but passengers are not. Remember
the Valujet crash. The initiating event was a cargo bay/cabin fire casued
by
improperly shipped O2 generators igniting in flight.

[Jack]

Bruce Hoult wrote:

> I personally know glider pilots here in New Zealand who have flown to
> betweeen 35,000 and 37,000 ft with only an ordinary oxygen mask, not a
> pressure system.
>
> The glider world record of 49,000 ft used a pressure system.

Thanks for getting back on topic for this NG.


Jack

[Eric Greenwell]

Bucky wrote:

> wrote:
>
>> 40,000 15 seconds
>> 35.000 20 seconds
>> 30,000 30 seconds
>
>
> I don't get it. Can't a person stay conscious for longer than 30
> seconds without breathing? Most people can hold their breath for over
> a minute.

If the drop in pressure is rapid, can a person hold in the air? Or
perhaps it is expelled because the pressure in the lungs is double the
cabin pressure?


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Bob Moore]

"pbc76049" > wrote
> Most passenger O2 systems use chemically generated O2.
> There are no bottles to check.

Depends on the age of the B-737. Boeing used pax bottles
for a long time. But this is immaterial to the discussion
of why the pilots did not have O2.

Bob Moore
ATP B-707 B-727
PanAm (retired)

[Brien K. Meehan]

Totally crap. Teach someone how lungs work.

[Bert Willing]

If the pressure drop is rapid, they need to exhale, otherwise their lungs
will burst. Just like surfacing in scuba diving.

--
Bert Willing

ASW20 "TW"


"Eric Greenwell" > a écrit dans le message de news:
...
> Bucky wrote:
>
>> wrote:
>>
>>> 40,000 15 seconds
>>> 35.000 20 seconds
>>> 30,000 30 seconds
>>
>>
>> I don't get it. Can't a person stay conscious for longer than 30
>> seconds without breathing? Most people can hold their breath for over
>> a minute.
>
> If the drop in pressure is rapid, can a person hold in the air? Or perhaps
> it is expelled because the pressure in the lungs is double the cabin
> pressure?
>
>
> --
> Change "netto" to "net" to email me directly
>
> Eric Greenwell
> Washington State
> USA

[Shawn]

wrote:
> In accounts of the crash of the Cypriot airliner in Greece, all I've
> read say that loss of cabin pressure could not, by itself, incapacitate
> the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
> this plane was at 35k) O2 supply by itself will not suffice to keep you
> conscious and that the drop down masks only give a false sense of
> security. He said that the ambient pressure is so low that even 100% O2
> does not provide enough to keep you conscious without a pressure
> breathing mask. If he's right, that could explain the crash, especially
> given that all it would take is 20 seconds of distraction (i.e., not
> donning the mask) to knock out the pilot as indicated in the table
> below. On the other hand, I checked and a standard atmosphere at 35k
> feet is 7.0 in of Hg, which is more than the partial pressure of O2 at
> sea level (6 in = 20% of 30 inches), which would seem to contradict the
> info given by the ATP. Any thoughts or corrections to my reasoning?
>
>
> Tlme of useful
> consciousness
> Altitude (ft) without oxygen
>
> 40,000 15 seconds
> 35.000 20 seconds
> 30,000 30 seconds
> 28,000 1 minute
> 26,000 2 minutes
> 24,000 3 minutes
> 22,000 6 minutes
> 20,000 10 minutes
> 15.000 Indefinite
>

Sure pp is 6" at sea level, but at 35 k ft (using your numbers) the pp
O2 is 20% of 7" or 1.4" Hg. At that pressure only about 50% of the
hemoglobin in your blood is saturated, and it hangs on to that O2 pretty
strongly, so it's not available for use by your brain (or anywhere else).

Shawn

[Stewart Kissel]

Also, many of the high-altitude climbers who do not
use oxygen have shown significant brain damage when
cat-scanned.



At 14:00 15 August 2005, Stefan wrote:
>John Kirksey wrote:
>
>> How, then, can someone like Ed Viesturs repeatedly
>>climb the tallest
>> mountain peaks in the world without supplemental oxygen?
>>Is it because of
>> the slower ascent and the time spent acclimating to
>>the higher altitudes?
>
>First, acclimatisation.
>
>Second, walking (and climbing) is different from flying.
>You don't need
>much brain to walk. When piloting, however, everything
>is about
>thinking. And it's the brain which needs the most oxygen.
>
>And maybe a third reason: There are exceptional people
>who are just
>better suited for such things than you and me.
>
>Stefan
>

[Shawn]

Peter Duniho wrote:
> "Bucky" > wrote in message
> oups.com...
>
>>I don't get it. Can't a person stay conscious for longer than 30
>>seconds without breathing? Most people can hold their breath for over
>>a minute.
>
>
> When they do that, they are using up a small reserve of oxygen-filled air
> contained in their lungs. Exhale as much air from your lungs as you can,
> and THEN see how long you can hold your breath.

At high altitude you breath out the oxygen bound to the hemoglobin in
your blood. Your blood gives up its O2 to the air. Hold your breath or
just stop breathing and you may last longer (never done the experiment
though ;-) ).

Shawn

[Happy Dog]

"John Kirksey" > wrote in message
news:cZ0Me.4596$H_4.4209@trnddc07...
>> Tlme of useful
>> consciousness
>> Altitude (ft) without oxygen
>>
>> 40,000 15 seconds
>> 35.000 20 seconds
>> 30,000 30 seconds
>> 28,000 1 minute
>
>
> How, then, can someone like Ed Viesturs repeatedly climb the tallest
> mountain peaks in the world without supplemental oxygen? Is it because of
> the slower ascent and the time spent acclimating to the higher altitudes?

That and by breathing like he's running a marathon. Sleep and you die.

mo

[Ian Johnston]

On Mon, 15 Aug 2005 04:21:32 UTC, wrote:

: Yet, I was once told by an ATP that at 40k feet (admittedly
: this plane was at 35k) O2 supply by itself will not suffice to keep you
: conscious...

Oxygen is only part of it. The breathing reflex is triggered by the
carbon dioxide partial pressure in your lungs: when atmospheric
pressure falls below that you never get the trigger and your lungs
just stop working. This is a Bad Thing.


Ian


--

[Stefan]

Happy Dog wrote:

> That and by breathing like he's running a marathon. Sleep and you die.

This is just plain bull****. It's all about partial pressure.

Stefan

[Scott Migaldi]

Ash Wyllie wrote:

> Seems to me that astronauts use 3psi of pure O2 during EVAs.
>
>
> -ash
> Cthulhu in 2005!
> Why wait for nature?
>

Correct and 3psi of pure O2 is about the same as the ppO2 in Air at Sea
Level.
--
--------------------
Scott F. Migaldi
CP-ASEL-IA
N8116B

PADI MI-150972
Join the PADI Instructor Yahoo Group
http://groups.yahoo.com/group/PADI-Instructors/

--------------------

[Happy Dog]

"Bert Willing" > wrote in
message ...
> If the pressure drop is rapid, they need to exhale, otherwise their lungs
> will burst. Just like surfacing in scuba diving.

I don't believe there's ever been a case of pulmonary barotrauma (absent of
prior lung pathology) from decompression in commercial aviation. The
differential between 50,000' and 8,000' is less than that typically involved
in scuba incidents. May be possible though.

moo

[Happy Dog]

"Stefan" > wrote in message
...
> Happy Dog wrote:
>
>> That and by breathing like he's running a marathon. Sleep and you die.
>
> This is just plain bull****. It's all about partial pressure.

Breathing technique is crucial to high altitude activity. The technique is
very similar to that used by joggers.

moo

[George Patterson]

Bucky wrote:
>
> I don't get it. Can't a person stay conscious for longer than 30
> seconds without breathing? Most people can hold their breath for over
> a minute.

If the aircraft loses pressure at 35,000', you cannot hold your breath. The
pressure difference will force you to exhale. Nothing you can do about it.

But that's not the biggest deal. The biggest problem is the fact that the
ambient pressure at that altitude is too low to keep oxygen in your bloodstream.
All the oxygen immediately begins to flow out of your bloodstream into your
lungs and out into the surrounding air. It doesn't matter whether you breathe
or not.

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.

[George Patterson]

wrote:
>
> Any thoughts or corrections to my reasoning?

The ATP is correct. While people do vary greatly, and some people have been able
to perform adequately without oxygen at 20,000' or more, most people can't go
much higher than 10,000' without suffering some ill effects. Because of this,
the FAA requires that a pilot use oxygen if they spend over 30 minutes above
12,500'.

In general, people can use a cranula or similar device to provide oxygen up to
about 20,000' (the FAA limits use of these to 18,000'). These simply bleed
oxygen into the air you breathe. Above that, you need a low-pressure mask. These
ensure that all you are breathing is oxygen and are good up to about 25,000'.
Above that, you need a pressure mask. Those increase the pressure of the oxygen
and work well up to about 35,000'. Above that, you need a pressure suit or a
pressurized aircraft.

The emergency drop-down masks for airline passengers are low-pressure. They
won't keep you conscious at 35,000', but they may keep you alive.

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.

[Duane Eisenbeiss]

"pbc76049" > wrote in message
...
> Most passenger O2 systems use chemically generated O2.
> There are no bottles to check. There are cabin walk around bottles
> and the flight deck is bottled O2, but passengers are not. Remember
> the Valujet crash. The initiating event was a cargo bay/cabin fire casued
> by
> improperly shipped O2 generators igniting in flight.
>
>
Even if the passengers have chemically generated O2, the pilots have O2 from
a bottle. Pilots are required (and most do) check their O2 before take-off.
The chemically generated O2 units cannot be turned off once in use and then
must be replaced. Therefore pilot positions have bottled O2.

Duane

[Ian Johnston]

On Mon, 15 Aug 2005 18:36:13 UTC, T o d d P a t t i s t
> wrote:

: "Ian Johnston" > wrote:
:
: >Oxygen is only part of it. The breathing reflex is triggered by the
: >carbon dioxide partial pressure in your lungs: when atmospheric
: >pressure falls below that you never get the trigger and your lungs
: >just stop working. This is a Bad Thing.
:
: Your lungs work OK, but there's not enough O2 to keep you
: conscious. ...

Thanks.

: Of course, at high altitudes, if the PP of CO2 is so low
: that your body fails to breathe, then that can cause of
: death, even if the PP of O2 would be high enough to keep you
: alive.

That's what I ws thinking of. Doesn't that effect kick in about thirty
something thousand feet?

Ian

[Don Johnstone]

At 19:12 15 August 2005, George Patterson wrote:
wrote:
>>
>> Any thoughts or corrections to my reasoning?
>
>The ATP is correct. While people do vary greatly, and
>some people have been able
>to perform adequately without oxygen at 20,000' or
>more, most people can't go
>much higher than 10,000' without suffering some ill
>effects. Because of this,
>the FAA requires that a pilot use oxygen if they spend
>over 30 minutes above
>12,500'.
>
>In general, people can use a cranula or similar device
>to provide oxygen up to
>about 20,000' (the FAA limits use of these to 18,000').
>These simply bleed
>oxygen into the air you breathe. Above that, you need
>a low-pressure mask. These
>ensure that all you are breathing is oxygen and are
>good up to about 25,000'.
>Above that, you need a pressure mask. Those increase
>the pressure of the oxygen
>and work well up to about 35,000'. Above that, you
>need a pressure suit or a
>pressurized aircraft.
>
>The emergency drop-down masks for airline passengers
>are low-pressure. They
>won't keep you conscious at 35,000', but they may keep
>you alive.
>
>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.
>
The pilots however are provided with pressure masks

[Happy Dog]

"Ian Johnston" > wrote in message
> > wrote:
> : Of course, at high altitudes, if the PP of CO2 is so low
> : that your body fails to breathe, then that can cause of
> : death, even if the PP of O2 would be high enough to keep you
> : alive.
>
> That's what I ws thinking of. Doesn't that effect kick in about thirty
> something thousand feet?

It starts at about 14,000 feet. People sleeping above this altitude can
suffer a condition called "Periodic Breathing". This is a cycle of
breathing until CO2 levels drop (the body enters a state of alkalosis), then
breathing stops, CO2 levels rise, the body responds by gasping and
hyperventilating and then stops breathing again. As altitude goes up, the
effect becomes nastier. And a bunch of other bad things become a looming
possibility.

le m

[Derrick Steed]

This is a message to Andy Kirkland: one thing is VERY apparent to from
the current thread about the Cypriot airliner, that relating to the
HusBos fatality, and the Nimbus 4 and big wings discussion, and that is
that most subscribers to this group suffer from a morbid fascination
with speculation about tragic accidents with scant regard for the
feelings of those who may have been directly affected by them.

Wouldn't it be useful to have a group for the sole purpose of
discussions relating to the type of morbid speculation and various
exchanges of ignorance that we are currently being subjected to?

Now, where did I put that fireproof suit?

Rgds,

Derrick Steed

[Happy Dog]

"T o d d P a t t i s t" > wrote in message
> "Ian Johnston" > wrote:
>
>>: Of course, at high altitudes, if the PP of CO2 is so low
>>: that your body fails to breathe, then that can cause of
>>: death, even if the PP of O2 would be high enough to keep you
>>: alive.
>>
>>That's what I ws thinking of. Doesn't that effect kick in about thirty
>>something thousand feet?
>
> It's no lower than that, and is typically higher. I'm not
> sure of the actual point.

That the breathing response is diminished? It starts much lower. But the
rest of your post indicates that you agree with that.
> I've been through the
> FAA/military oxygen training 3 times and I've flown to 30K'
> in a glider on 100% diluter demand O2. I was breathing
> deeply and carefully under conscious control, not relying on
> my breathing reflex.

That's a real feat. Without acclimatisation training, which, among other
things, increases hemoglobin counts, it's hard to stay usefully awake after
a rapid ascent to that altitude. If you used an oximeter, I'd be interested
in the readings. Did you notice any of the usual effects of hypoxia?

moo

[Eric Greenwell]

George Patterson wrote:

>
> In general, people can use a cranula or similar device to provide oxygen
> up to about 20,000' (the FAA limits use of these to 18,000'). These
> simply bleed oxygen into the air you breathe. Above that, you need a
> low-pressure mask. These ensure that all you are breathing is oxygen and
> are good up to about 25,000'.

My understanding is cannulas are still effective to at least 25,000',
and the FAA mask requirement is only to guard against pilots that might
inadvertently breathe through their mouth instead of their nose. The
masks I've used all allow ambient air into the mask; i.e., they are not
intended to supply only oxygen. They used staged valves for constant
flow systems, or just small holes in the sides of the mask for
pulse-delivery devices like Mountain High's EDS controller.



--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Derrick Steed]

>Derrick Steed wrote:

>one thing is VERY apparent to from
>the current thread about the Cypriot airliner, that relating to the
>HusBos fatality, and the Nimbus 4 and big wings discussion, and that is
>that most subscribers to this group suffer from a morbid fascination
>with speculation about tragic accidents with scant regard for the
>feelings of those who may have been directly affected by them.

Todd Pattist Wrote:
I've posted in all three of those threads, and feel neither
a morbid fascination, nor any desire to speculate about the
actual causes. Nor do I see those characteristics in other
posters. I do see a desire to understand and prevent
accidents and I wonder how far you would go to prevent
safety discussions.=20

AFAIK, no one here is directly connected to the Cypriot
airliner accident, but many of us do face the dangers of
high altitude oxygen flight. The report on the Nimbus 4
accident was issued long ago, and the discussion seemed to
be about whether using airbrakes is advisable during
recovery. Don't you think that discussion is helpful? When
would you allow it here?

As to the HusBos accident, I understand your feelings, but
ultimately believe that trying to understand an accident is
the only way to prevent it from happening again. I think we
owe that to both those who died and those who might yet
live.=20

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~

Todd, I'm not complaining about the discussion of safety issues. I
welcome that and other discussions of a technical nature which foster a
greater understanding of our sport and how to be good at it while
maintaining safety. I find such discussions to be interesting and
sometimes educational and if I were to see these discussions continuing
as a reasonable level great, However, a trawl through the posts on this
group over the past year or so reveals the following: a) long periods
with nothing much about (for instance) safety being said, b) following
the occurrence of some notable event (especially those relating to some
accident) there is a burst of discussion relating to the factors which
may or may not have contributed that accident. It's like looking at an
attack and decay curve: incident happens, rapid escalation of discussion
on that topic, discussion dies down, another incident occurs, rapid
escalation of discussion, etc...

What I find objectionable is that in case (b) one is then subjected to
the spectacle of various personal agendas being vented on a soapbox
(supposedly) justified by the occurrence of the event being discussed.
There was the HusBos spinning accident - a long burst of discussion
ensued as a result with various theories and personal analyses of the
incident being put forward prior to any factual report of what actually
occurred (I had personally known for some years and had flown with the
instructor concerned some months previous to that tragic event), then
there were the Nimbus 4 discussions, then the latest HusBos incident,
lastly the airline crash (this is not a complete list I'm sure). In each
case there was an absence of any previous discussion relating to the
topic for some considerable time preceding the event - then, the event
occurs and, all of a sudden, soapboxes are rolled out, the analysis
begins, and the various correspondents put forward their version of
events (amazing considering most of them were not even there!).

In all of the discussions referred to, various opinions were shared with
the group, some valid, many inappropriate given the proximity of the
event and the need for an objective investigation to be carried out, not
to mention the involvement of the authorities and the due process of
law.

I just wish sometimes that we could collectively display a little
sensitivity and hold off on these discussions until the facts are known,
then discuss the pros and cons. I don't see that it is that urgent that
the discussions take place immediately, especially considering that the
same topics have come up again and again with little prospect of
agreement (and note that each time they come up, it is in response to
the occurrence of some incident).
=20
Rgds,

Derrick Steed

[Capt. Geoffry Thorpe]

"Stewart Kissel" > wrote in
message ...
> Also, many of the high-altitude climbers who do not
> use oxygen have shown significant brain damage when
> cat-scanned.
>
>

Before or after climbing without O2?

--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail
Spell checking is left as an excercise for the reader.

[5Z]

Derrick,
We (people) have a very short memory when it comes to many safety
issues. Wouldn't it be nice if the highway authorities left auto
wrecks on the side of the road for a few days or weeks to remind us of
how dangerous driving is?

When an unfortunate event occurs, it reminds some of us of our
mortality. Confronted with that, a portion want to talk about their
fears and concerns.

Consider a ground level railroad crossing. Pretty dangerous if you
ignore the signals, but after a while people get complacent and
actually even stop on the tracks due to traffic congestion. Then
someone gets hurt or killed and an uproar wells up to have a bridge
built. After a few weeks it dies down and life goes on. A few weeks
later, we again see people stopped on the tracks...

Fortunately, in aviation we don't have too many of these folks who stop
on the tracks. We generally have experienced pilots doing something
that confounds (some of) us. So we talk it out and try to explore all
the ways WE might get into and out of the same situation. We're not
always analyzing the specific accident, rather we examine the
circumstances that have been brough before us and how we might deal
with a similar situation.

-Tom

[Derrick Steed]

Tom wrote:
Derrick,
We (people) have a very short memory when it comes to many safety
issues. Wouldn't it be nice if the highway authorities left auto
wrecks on the side of the road for a few days or weeks to remind us of
how dangerous driving is?

When an unfortunate event occurs, it reminds some of us of our
mortality. Confronted with that, a portion want to talk about their
fears and concerns.

Consider a ground level railroad crossing. Pretty dangerous if you
ignore the signals, but after a while people get complacent and
actually even stop on the tracks due to traffic congestion. Then
someone gets hurt or killed and an uproar wells up to have a bridge
built. After a few weeks it dies down and life goes on. A few weeks
later, we again see people stopped on the tracks...

Fortunately, in aviation we don't have too many of these folks who stop
on the tracks. We generally have experienced pilots doing something
that confounds (some of) us. So we talk it out and try to explore all
the ways WE might get into and out of the same situation. We're not
always analyzing the specific accident, rather we examine the
circumstances that have been brough before us and how we might deal
with a similar situation.

-Tom

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~

Tom,

I'm aware of the points you make and have been for (more than three)
decades. It doesn't make the recent posts any more the right way to
approach the subject, especially considering the distress it would cause
some who might read it.

But, in a way, I suppose you're right. _My_ expectations of people _are_
probably way too high.

Rgds,

Derrick Steed

[Dave S]

CO2 is generated by cellular respiration. This is essentially
independent of oxygen, as a matter of fact, anaerobic respiration can
occur in the absense of adequate oxygen, but it is VERY inefficient, and
makes LOTS of waste products.

Arterial CO2 concentration, having left the lungs, is around 35-45 torr
(mmHg). In mixed venous blood, returning to the lungs, it is around 50
torr/mmhg or so.

At sea level, atmospheric CO2 is in the high 20's/low 30's mmhg. The
body's buffer system in a healthy individual will RAPIDLY move the CO2
level back towards normal if it vary's too much from those values. So,
even at altitude, your venous blood gas values are pretty much normal
after one pass around the body. You hold your breath, and this blood
with "venous" levels of CO2 will make a second pass, and when it hits
the chemo and baro receptors in in your carotid (artery) bodies you will
start getting that URGE to breath.

All of this is independent of how oxygen is handled by the blood. Each
gas's function in the body is more or less independent of each other.
Even though your body uses oxygen to make CO2 as a waste product, your
body will continue to make CO2 for a short time without adequate oxygen.
As an example: the burn in your muscles after a sprint - lactic acid
generated along with CO2 when the oxygen requirement of the muscles
outstrips the oxygen supply.

To say "the lungs stop working" is at best, technically inaccurate. You
are just too hypoxic to make the muscles responsible for gas exchange to
work properly.

Dave

[Bruce Hoult]

In article <%N5Me.1542$yb.46@trndny01>,
George Patterson > wrote:

> Because of this, the FAA requires that a pilot use oxygen if they
> spend over 30 minutes above 12,500'.

My recollection of my O2 training is that the rule is 30 minutes over
10,000 ft, or if you go over 12,500 ft at *all*.

But I've only been to about 20,000 ft in a glider, unlike some people I
know who have been far higher.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[fred]

"Bruce Hoult" > wrote in message
...
> In article <%N5Me.1542$yb.46@trndny01>,
> George Patterson > wrote:
>
>> Because of this, the FAA requires that a pilot use oxygen if they
>> spend over 30 minutes above 12,500'.
>
> My recollection of my O2 training is that the rule is 30 minutes over
> 10,000 ft, or if you go over 12,500 ft at *all*.


Is that cockpit pressure or actual altitude??

[Bill Daniels]

"Happy Dog" > wrote in message
.. .
> "T o d d P a t t i s t" > wrote in message
> > "Ian Johnston" > wrote:

> That's a real feat. Without acclimatisation training, which, among other
> things, increases hemoglobin counts, it's hard to stay usefully awake
after
> a rapid ascent to that altitude. If you used an oximeter, I'd be
interested
> in the readings. Did you notice any of the usual effects of hypoxia?
>
> moo
>
I flew a glider to over 29,000 feet with an A-14 diluter demand system and a
pulse oximeter. It showed a solid 98% SpO2. I have flown to more than
38,000 feet with an A-14 and felt fine but I didn't have a oximeter.

The military systems like the A-14 are good to 38,000 feet according to the
manuals. Above that, a pressure demand system is needed like the US Navy A1
or the USAF A15 with matching pressure demand mask. The pressure demand
system is good to over 50,000 feet, again according to the manuals. The US
Navy A1 system manual specifically says normal SpO2 to 55,000.

Note that a pressure demand mask is very hard to breathe through below about
20,000 feet because of the effort to work the double check valves.

Bill Daniels

[George Patterson]

Bruce Hoult wrote:
>
> My recollection of my O2 training is that the rule is 30 minutes over
> 10,000 ft, or if you go over 12,500 ft at *all*.

No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over that at
all. At 15,000', passengers also have to be on oxygen. Section 91.211.

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.

[George Patterson]

fred wrote:
>
>>In article <%N5Me.1542$yb.46@trndny01>,
>>George Patterson > wrote:
>>
>>>Because of this, the FAA requires that a pilot use oxygen if they
>>>spend over 30 minutes above 12,500'.
>
> Is that cockpit pressure or actual altitude??

Cabin pressure altitude.

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.

[Mike Rapoport]

"Bruce Hoult" > wrote in message
...
> In article <%N5Me.1542$yb.46@trndny01>,
> George Patterson > wrote:
>
>> Because of this, the FAA requires that a pilot use oxygen if they
>> spend over 30 minutes above 12,500'.
>
> My recollection of my O2 training is that the rule is 30 minutes over
> 10,000 ft, or if you go over 12,500 ft at *all*.
>
Better review the rules;

Mike
MU-2

[Don Tuite]

On Tue, 16 Aug 2005 02:44:54 GMT, George Patterson
> wrote:

>Bruce Hoult wrote:
>>
>> My recollection of my O2 training is that the rule is 30 minutes over
>> 10,000 ft, or if you go over 12,500 ft at *all*.
>
>No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over that at
>all. At 15,000', passengers also have to be on oxygen. Section 91.211.

This is all irrelevant if there is no oxygen in the system. That'd
be my guess. Too much trouble to check or refill. Tanks at the
airport are empty. Somebody sold them to a welder . . . .

Don

[Bob Korves]

George Patterson > wrote in
news:GqcMe.161$zb.155@trndny04:

> Bruce Hoult wrote:
>>
>> My recollection of my O2 training is that the rule is 30 minutes over
>> 10,000 ft, or if you go over 12,500 ft at *all*.
>
> No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over
> that at all. At 15,000', passengers also have to be on oxygen. Section
> 91.211.
>
> 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.

Almost, but not quite correct.

91.211a(1,2) says "...flight crew is PROVIDED WITH AND USES (emphasis mine)
supplemental oxygen" at the 12,500 and 14,000 foot altitudes as you
correctly noted.

91.211a(3) says "...above 15,000 feet (MSL) unless each occupant is
PROVIDED WITH supplemental oxygen." Your passengers are never required to
be USING oxygen.

Yes, it's a minor point...
-Bob Korves

[Shawn]

George Patterson wrote:
> Bruce Hoult wrote:
>
>>
>> My recollection of my O2 training is that the rule is 30 minutes over
>> 10,000 ft, or if you go over 12,500 ft at *all*.
>
>
> No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over
> that at all. At 15,000', passengers also have to be on oxygen. Section
> 91.211.
>
> 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.

You should check Bruce's Lat/Long in his sig before you start quoting
him US FARs.

Shawn

[Sylvain]

George Patterson wrote:
> No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over
> that at all. At 15,000', passengers also have to be on oxygen. Section
> 91.211.

actually the passengers must be *provided* with oxygen; notice
the different wording between 91.211(a)(2) and 91.211(a)(3);
i.e., your passengers do not have to be *on* oxygen (makes
for much quieter passengers, and saves on o2 refills :-)))

--Sylvain

[Brien K. Meehan]

T o d d P a t t i s t wrote:
> Wrong. the partial pressure has everything to do with it.

Wrong, the partial pressure has nothing to do with it.

> The lungs (or more accurately the blood in the lungs) need
> O2 pressure to pick up O2. That O2 pressure is referred to
> as the partial pressure of O2. You can be at altitude on
> 100% O2 and have the same partial pressure as at sea level
> on partial O2

The lungs (not the blood) need pressure to allow gas exchange
(respiration) in the alveoli. The pressure (or lack thereof)
determines the effectiveness of respiration. Reduced effectiveness can
be compensated for with supplemental oxygen.

> Sounds like you don't understand the process.

I think we're talking about different parts of the process. It sounds
like you don't know what I mean by respiration.

> You may be referring to the breathing reflex
> that requires sufficient CO2 to trigger breathing ...

I did not refer to that.

> The original question was why you lose consciousness faster
> at altitude than if you hold your breath at sea level.

The original question is why you lose consciousness at altitude with
supplemental oxygen when the partial pressure of oxygen appears to be
the same as at sea level. It had nothing to do with holding one's
breath.

> True - because the PP drops too low for consciousness or
> life. It's all about PP of O2.

True because the lungs become unable to respirate effectively at
reduced atmospheric pressure, which leads to hypoxia.

[Bruce Hoult]

In article <GqcMe.161$zb.155@trndny04>,
George Patterson > wrote:

> Bruce Hoult wrote:
> >
> > My recollection of my O2 training is that the rule is 30 minutes over
> > 10,000 ft, or if you go over 12,500 ft at *all*.
>
> No. 12,500' if you exceed it for 30 minutes or 14,000' if you go over that at
> all. At 15,000', passengers also have to be on oxygen. Section 91.211.

I don't see a section 91.211 in the New Zealand regulations.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[Don Johnstone]

In some ways Derricks' point is well made but as always
there are other factors. The point concerning the bereaved
and jumping to early conclusions without know facts
is particulary cogent. It is very easy to find a solution
to a problem that does not exist or even worse a solution
which is worse than the original problem.
On the other hand some accidents can give us all a
heads up to the things that might cause us harm. It
is perfectly legitimate to take the outcome of an accident
and think of ways in which we can avoid that outcome
without speculating on the causes which led up to the
particular incident. It is difficult to achieve a balance
and perhaps taking a little time to reflect on the
effect such discussion might have on others is required.
In the case of the incident which started this thread
I feel the lesson is simple. If you intend to fly at
altitude you better make damm sure you have an adequate
supply of oxygen. While I find the discussion of partial
oxygen pressure and the way in which I might come to
harm interesting I think that all I really need to
know is that if I go high without oxygen I will probably
die from it, why is of lesser importance. I am keen
to avoid dying, I have no intention of exploring the
way in which this could happen.

DAJ
ASW17 401 - Wave flying floats my boat.

At 22:24 15 August 2005, Derrick Steed wrote:
>Tom wrote:
>Derrick,
>We (people) have a very short memory when it comes
>to many safety
>issues. Wouldn't it be nice if the highway authorities
>left auto
>wrecks on the side of the road for a few days or weeks
>to remind us of
>how dangerous driving is?
>
>When an unfortunate event occurs, it reminds some of
>us of our
>mortality. Confronted with that, a portion want to
>talk about their
>fears and concerns.
>
>Consider a ground level railroad crossing. Pretty dangerous
>if you
>ignore the signals, but after a while people get complacent
>and
>actually even stop on the tracks due to traffic congestion.
>Then
>someone gets hurt or killed and an uproar wells up
>to have a bridge
>built. After a few weeks it dies down and life goes
>on. A few weeks
>later, we again see people stopped on the tracks...
>
>Fortunately, in aviation we don't have too many of
>these folks who stop
>on the tracks. We generally have experienced pilots
>doing something
>that confounds (some of) us. So we talk it out and
>try to explore all
>the ways WE might get into and out of the same situation.
>We're not
>always analyzing the specific accident, rather we examine
>the
>circumstances that have been brough before us and how
>we might deal
>with a similar situation.
>
>-Tom
>
>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~
>
>Tom,
>
>I'm aware of the points you make and have been for
>(more than three)
>decades. It doesn't make the recent posts any more
>the right way to
>approach the subject, especially considering the distress
>it would cause
>some who might read it.
>
>But, in a way, I suppose you're right. _My_ expectations
>of people _are_
>probably way too high.
>
>Rgds,
>
>Derrick Steed
>
>
>
>
>
>
>
>

[HL Falbaum]

There are other, important, limiting factors. The alveoli need to exchange
two gases--CO2 and O2 and pressure gradients are needed for this. The fly in
the ointment is that water vapor pressure in the alveoli remains near
constant at 47mm Hg (Torr). The CO2 comes from diffusion across the
capillary-alveolar barrier, from the blood, and therefore remains somewhat
high and at 30,000 ft is about 30 mm Hg. So the O2 must ovecome this
pressure and about 30 mm more to get into the blood effectively. So unless
the O2 is above about 107 mm Hg you don't get enough in your blood to do you
any good.

--
Hartley Falbaum,


"Brien K. Meehan" > wrote in message
oups.com...
>T o d d P a t t i s t wrote:
>> Wrong. the partial pressure has everything to do with it.
>
> Wrong, the partial pressure has nothing to do with it.
>
>> The lungs (or more accurately the blood in the lungs) need
>> O2 pressure to pick up O2. That O2 pressure is referred to
>> as the partial pressure of O2. You can be at altitude on
>> 100% O2 and have the same partial pressure as at sea level
>> on partial O2
>
> The lungs (not the blood) need pressure to allow gas exchange
> (respiration) in the alveoli. The pressure (or lack thereof)
> determines the effectiveness of respiration. Reduced effectiveness can
> be compensated for with supplemental oxygen.
>
>> Sounds like you don't understand the process.
>
> I think we're talking about different parts of the process. It sounds
> like you don't know what I mean by respiration.
>
>> You may be referring to the breathing reflex
>> that requires sufficient CO2 to trigger breathing ...
>
> I did not refer to that.
>
>> The original question was why you lose consciousness faster
>> at altitude than if you hold your breath at sea level.
>
> The original question is why you lose consciousness at altitude with
> supplemental oxygen when the partial pressure of oxygen appears to be
> the same as at sea level. It had nothing to do with holding one's
> breath.
>
>> True - because the PP drops too low for consciousness or
>> life. It's all about PP of O2.
>
> True because the lungs become unable to respirate effectively at
> reduced atmospheric pressure, which leads to hypoxia.
>

[Stanford Korwin]

At 12:54 16 August 2005, Hl Falbaum wrote:
>There are other, important, limiting factors. The alveoli
>need to exchange
>two gases--CO2 and O2 and pressure gradients are needed
>for this. The fly in
>the ointment is that water vapor pressure in the alveoli
>remains near
>constant at 47mm Hg (Torr). The CO2 comes from diffusion
>across the
>capillary-alveolar barrier, from the blood, and therefore
>remains somewhat
>high and at 30,000 ft is about 30 mm Hg. So the O2
>must ovecome this
>pressure and about 30 mm more to get into the blood
>effectively. So unless
>the O2 is above about 107 mm Hg you don't get enough
>in your blood to do you
>any good.
>
>--
>Hartley Falbaum,
>

Good for you Hartley !

The alveolar 'head of steam' is, very much, the ******
in the gas exchange woodpile at altitude.

OOPS - PC - as if I care !!

s(a)ta13nski.

[Tony Verhulst]

Stewart Kissel wrote:
> Also, many of the high-altitude climbers who do not
> use oxygen have shown significant brain damage when
> cat-scanned.

Interesting! Do you have a reference?

Tony V.

[Darrell S]

Bucky wrote:
> wrote:
>> 40,000 15 seconds
>> 35.000 20 seconds
>> 30,000 30 seconds
>
> I don't get it. Can't a person stay conscious for longer than 30
> seconds without breathing? Most people can hold their breath for over
> a minute.

If you try to hold your breath your lungs will explode when the outside
pressure drops. That's why in altitude chambers they never tell you when
they're going to give the explosive decompression. When it happens the air
in your lungs automatically expels from your body since it is at a much
higher pressure than the ambient air. Pressure breathing through an oxygen
mask is difficult since your must manually forcibly exhale and just relax to
inhale.

--

Darrell R. Schmidt
B-58 Hustler History: http://members.cox.net/dschmidt1/
-

[Stewart Kissel]

At 13:18 16 August 2005, Tony Verhulst wrote:
>Stewart Kissel wrote:
>> Also, many of the high-altitude climbers who do not
>> use oxygen have shown significant brain damage when
>> cat-scanned.
>
>Interesting! Do you have a reference?
>
>Tony V.

Yep...

http://www.batnet.com/mfwright/everest.html

If you google about on this subject, there is some
interesting stuff. FWIW, I have heard secondhand
and completely unsubstantiated that some of the wave
flyers of the '60's and '70's, when going way high
was more in vogue, are also exhibiting damage.
>

[Tony Verhulst]

>>>Also, many of the high-altitude climbers who do not
>>>use oxygen have shown significant brain damage when
>>>cat-scanned.

>>Interesting! Do you have a reference?

> Yep...
>
> http://www.batnet.com/mfwright/everest.html

Thanks and Yikes!

tony V.

[Stewart Kissel]

>Thanks and Yikes!
>
>tony V.
>
Your welcome...what would be interesting is to compare
this sort of damage to what a heavy smoker/drinker
might exhibit(if anything).

[George Patterson]

Shawn wrote:
>
> You should check Bruce's Lat/Long in his sig before you start quoting
> him US FARs.

My original post stated that "the FAA requires that a pilot use oxygen if they
spend over 30 minutes above 12,500'." He said that was wrong. Doesn't matter
where he happens to live, the FAA *still* requires that a pilot use oxygen if
they spend over 30 minutes above 12,500'.

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.

[George Patterson]

Bruce Hoult wrote:
>
> I don't see a section 91.211 in the New Zealand regulations.

I didn't say there was. *You* said the FAA didn't have this requirement.

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.

[John Gaquin]

"Bob Moore" > wrote in message
>
> My thoughts on yesterday's accident.

My thoughts were tending in the same direction, Bob. Speculation on the
availability of O2, or the system integrity, is fine, but the first and most
obvious question to me was as to why the airplane was still at altitude.
Job 1, superceding all others, is to get the craft to breathable air. What
was going on? All it takes is one body in the cockpit to initiate the
descent.

JG

[Eric Greenwell]

John Gaquin wrote:
> "Bob Moore" > wrote in message
>
>>My thoughts on yesterday's accident.
>
>
> My thoughts were tending in the same direction, Bob. Speculation on the
> availability of O2, or the system integrity, is fine, but the first and most
> obvious question to me was as to why the airplane was still at altitude.
> Job 1, superceding all others, is to get the craft to breathable air. What
> was going on? All it takes is one body in the cockpit to initiate the
> descent.

The news tonight said the airliner was on autopilot, in climb mode,which
it continued in until finally reaching it's service ceiling. My
understanding is Job 1 is to put on an oxygen mask, which, if it failed
to deliver oxygen, might mean they never get to Job 2 (descend).


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Shawn]

George Patterson wrote:
> Shawn wrote:
>
>>
>> You should check Bruce's Lat/Long in his sig before you start quoting
>> him US FARs.
>
>
> My original post stated that "the FAA requires that a pilot use oxygen
> if they spend over 30 minutes above 12,500'." He said that was wrong.
> Doesn't matter where he happens to live, the FAA *still* requires that a
> pilot use oxygen if they spend over 30 minutes above 12,500'.

Guess you read it differently than me. I read it as him stating his
experience, rather than correcting you. Usenet you know, it happens.
I know you're correct re the U.S. regs (unless they've changed since
April). I suspect Bruce is correct re the NZ regs given his previous
posting history on ras.
Both sets are really irrelevant in this case. Greek regs would apply.

> 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.

That's funny. :)

Shawn

[Bruce Hoult]

In article <ecxMe.681$wb.595@trndny09>,
George Patterson > wrote:

> Bruce Hoult wrote:
> >
> > I don't see a section 91.211 in the New Zealand regulations.
>
> I didn't say there was. *You* said the FAA didn't have this requirement.

I did not mention the FAA at all. I mentioned the training I received.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[Steven P. McNicoll]

"Bruce Hoult" > wrote in message
...
>
> I did not mention the FAA at all. I mentioned the training I received.
>

Yes, in response to a comment on the FAA requirement.

[Michelle P]

The pilots do not have drop down masks and separate O2 system designed
to last at least twice as long as the passengers.
Michelle

wrote:

>In accounts of the crash of the Cypriot airliner in Greece, all I've
>read say that loss of cabin pressure could not, by itself, incapacitate
>the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
>this plane was at 35k) O2 supply by itself will not suffice to keep you
>conscious and that the drop down masks only give a false sense of
>security. He said that the ambient pressure is so low that even 100% O2
>does not provide enough to keep you conscious without a pressure
>breathing mask. If he's right, that could explain the crash, especially
>given that all it would take is 20 seconds of distraction (i.e., not
>donning the mask) to knock out the pilot as indicated in the table
>below. On the other hand, I checked and a standard atmosphere at 35k
>feet is 7.0 in of Hg, which is more than the partial pressure of O2 at
>sea level (6 in = 20% of 30 inches), which would seem to contradict the
>info given by the ATP. Any thoughts or corrections to my reasoning?
>
>
> Tlme of useful
> consciousness
> Altitude (ft) without oxygen
>
> 40,000 15 seconds
> 35.000 20 seconds
> 30,000 30 seconds
> 28,000 1 minute
> 26,000 2 minutes
> 24,000 3 minutes
> 22,000 6 minutes
> 20,000 10 minutes
> 15.000 Indefinite
>
>
>

[W.J. \(Bill\) Dean \(U.K.\).]

For those who want to read about the medical aspects of Hypoxia, see United
States Naval Flight Surgeon's Manual: Third Edition 1991: Chapter 1:
Physiology of Flight, http://www.vnh.org/FSManual/01/03Hypoxia.html .

Also, have a look at Dr. Daniel L. Johnson's web site
http://amygdala.danlj.org/~danlj/AviationMedicine/index.html .

For those who want to read about actual incidents of hypoxia which did not
lead to an accident, see:

Boeing 737 Incident 98.08.13 Report June 99:
http://www.aaib.gov.uk/cms_resources/dft_avsafety_pdf_501410.pdf

Jet Provost Incident 02.08.18 Report Aug. 03:
http://www.aaib.gov.uk/cms_resources/dft_avsafety_pdf_023414.pdf

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

>
> > wrote in message
> oups.com...
>
> In accounts of the crash of the Cypriot airliner in Greece, all I've
> read say that loss of cabin pressure could not, by itself, incapacitate
> the pilot. Yet, I was once told by an ATP that at 40k feet (admittedly
> this plane was at 35k) O2 supply by itself will not suffice to keep you
> conscious and that the drop down masks only give a false sense of
> security. He said that the ambient pressure is so low that even 100% O2
> does not provide enough to keep you conscious without a pressure
> breathing mask. If he's right, that could explain the crash, especially
> given that all it would take is 20 seconds of distraction (i.e., not
> donning the mask) to knock out the pilot as indicated in the table
> below. On the other hand, I checked and a standard atmosphere at 35k
> feet is 7.0 in of Hg, which is more than the partial pressure of O2 at
> sea level (6 in = 20% of 30 inches), which would seem to contradict the
> info given by the ATP. Any thoughts or corrections to my reasoning?
>
>
> Tlme of useful
> consciousness
> Altitude (ft) without oxygen
>
> 40,000 15 seconds
> 35.000 20 seconds
> 30,000 30 seconds
> 28,000 1 minute
> 26,000 2 minutes
> 24,000 3 minutes
> 22,000 6 minutes
> 20,000 10 minutes
> 15.000 Indefinite
>

[For Example John Smith]

The chart is for time of USEFUL consciousness. The part where the pilot
starts thinking "I feel really great. Look how beautiful the scenery is.
The cold is my friend...." isn't useful consciousness.
"Bucky" > wrote in message
oups.com...
> wrote:
> > 40,000 15 seconds
> > 35.000 20 seconds
> > 30,000 30 seconds
>
> I don't get it. Can't a person stay conscious for longer than 30
> seconds without breathing? Most people can hold their breath for over
> a minute.
>

[Derrick Steed]

What I don't get is:

1. how you get a very hard to put out fuel fire from a crashed aeroplane
that was empty of fuel

2. considering that the flight was from Cyprus Larnaca to Athens and the
aircraft crashed on route - again, how come it ran out of fuel?

Morbid curiousity and a penchant for conspiracy theories is taking hold.

Rgds,

Derrick Steed

[Eric Greenwell]

Derrick Steed wrote:

> What I don't get is:
>
> 1. how you get a very hard to put out fuel fire from a crashed aeroplane
> that was empty of fuel
>
> 2. considering that the flight was from Cyprus Larnaca to Athens and the
> aircraft crashed on route - again, how come it ran out of fuel?

Our news reports (Western USA) said the aircraft flew over it's
destination at 35,000', so it doesn't sound like it ran out of fuel on
route. The crash seemed to be attributed to disengagement of the
autopilot, perhaps by someone, or by a problem in the system.


--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[W.J. \(Bill\) Dean \(U.K.\).]

If all on board where incapacitated with the autopilot engaged, it may have
simply flown until the fuel ran out. If the autopilot was programmed to fly
it to the destination and then join a holding pattern, it could have done
this until it ran out of fuel.

If anyone handled the controls, the autopilot would have disengaged.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

"Eric Greenwell" > wrote in message
...
> Derrick Steed wrote:
>
>> What I don't get is:
>>
>> 1. how you get a very hard to put out fuel fire from a crashed aeroplane
>> that was empty of fuel
>>
>> 2. considering that the flight was from Cyprus Larnaca to Athens and the
>> aircraft crashed on route - again, how come it ran out of fuel?
>
> Our news reports (Western USA) said the aircraft flew over it's
> destination at 35,000', so it doesn't sound like it ran out of fuel on
> route. The crash seemed to be attributed to disengagement of the
> autopilot, perhaps by someone, or by a problem in the system.
>
>
> --
> Change "netto" to "net" to email me directly
>
> Eric Greenwell
> Washington State
> USA

[Bruce Hoult]

In article t>,
"Steven P. McNicoll" > wrote:

> "Bruce Hoult" > wrote in message
> ...
> >
> > I did not mention the FAA at all. I mentioned the training I received.
> >
>
> Yes, in response to a comment on the FAA requirement.

Yes, pointing out that altitudes and durations where oxygen is required
are, like automobile speed limits, is not a hard and fast
physically-significant thing but rathe a matter of someone's opinion,
and that opinions differ in different places.

--
Bruce | 41.1670S | \ spoken | -+-
Hoult | 174.8263E | /\ here. | ----------O----------

[Steven P. McNicoll]

"Bruce Hoult" > wrote in message
...
>
> Yes, pointing out that altitudes and durations where oxygen is required
> are, like automobile speed limits, is not a hard and fast
> physically-significant thing but rathe a matter of someone's opinion,
> and that opinions differ in different places.
>

I was just pointing out that you had mentioned the FAA.