O2 and Cypriot airliner crash

"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

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

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

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

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 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

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

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.

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.

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.