What's minimum safe O2 level?

"Ron Rosenfeld" wrote in message
...
On Sun, 7 Nov 2004 17:58:17 -0500, "Icebound"
wrote:

Wasn't that borderline violation of the FARs 91.211? (30 mins above 12,500
pressure altitude)

What is a "borderline violation"?

Is the same as almost but not quite contrary to the regulations? If so,
then you've answered your question.

It was a rhetorical question. The real question was:
Why would you want to fly for 3.5 hours at the edge of a condition which the
FARs state is only safe for 30 minutes or less? Since, technically, it
might not have been a violation if the altimeter setting was more than
29.92, I can see stretching it a bit... maybe 45 minutes or an hour. But
3.5???

On Mon, 8 Nov 2004 11:31:46 -0500, "Icebound"
wrote:

It was a rhetorical question. The real question was:
Why would you want to fly for 3.5 hours at the edge of a condition which the
FARs state is only safe for 30 minutes or less? Since, technically, it
might not have been a violation if the altimeter setting was more than
29.92, I can see stretching it a bit... maybe 45 minutes or an hour. But
3.5???

Well, the way you initially phrased it was as a potential violation, which
it is not.

OTOH, there are many ways to be legal and not safe (as well as ways to be
safe but not legal). So, for me, anyway, I look at the two separately, and
I don't try to equate one with the other.

For example, flying for 3.5 at 12,500 is probably less safe than doing it
with oxygen. Especially for a sea level dweller who smokes 2 packs of
cigarettes/day. --Legal but not safe--

OTOH, someone who was born and bred and lived most all his life in
Leadville, CO, could probably fly with no problem (and no oxygen) at
13,000' all day long --Safe but not legal--




Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Ron Rosenfeld" wrote in message
...
On Mon, 8 Nov 2004 11:31:46 -0500, "Icebound"
wrote:

It was a rhetorical question. The real question was:
Why would you want to fly for 3.5 hours at the edge of a condition which
the
FARs state is only safe for 30 minutes or less? Since, technically, it
might not have been a violation if the altimeter setting was more than
29.92, I can see stretching it a bit... maybe 45 minutes or an hour. But
3.5???

Well, the way you initially phrased it was as a potential violation, which
it is not.

Well, to be precise, we do not know whether it was a violation or not.

If he was 12,500 indicated, for the whole 3.5 hours, and the actual
altimeter setting was less than 29.92 along more that 30 minutes of the
route, then the "pressure altitude" would have been higher than 12,500 in
that portion, and it *would* be a violation. If the actual altimeter
setting was at or above 29.92 then it would *not* be a violation.

Cub Driver wrote:
(One of the ski
patrol tricks with ailing turkeys is to have them breath into a paper
bag, to *cut down* on their oxygen intake.)

ABSOLUTELY WRONG.... hyperventilation is treated by increasing the CO2
content..The paper bag's therapeutic effect is acheived by allowing CO2
to be rebreathed, and hindering its passage from the body. Hypocapnia is
not treated by inducing hypoxia.

Dave

Icebound wrote:

The real question was:
Why would you want to fly for 3.5 hours at the edge of a condition which the
FARs state is only safe for 30 minutes or less?

Why would you automatically assume that because something is LEGAL that
it is also automatically safe?

Dave

"Dave S" wrote in message
ink.net...


Icebound wrote:

The real question was:
Why would you want to fly for 3.5 hours at the edge of a condition which
the FARs state is only safe for 30 minutes or less?

Why would you automatically assume that because something is LEGAL that it
is also automatically safe?


I didn't say it was safe. I said that the FARs said it was safe.

That was a slight mis-type in that actually I meant that the FARs *implied*
it was safe.

Therefore they imply that above 12,500 for more than 30 mins without oxygen
is unsafe. Certain things I accept as the cumulative knowledge of those who
went before me :-)

On Mon, 8 Nov 2004 19:28:20 -0500, "Icebound"
wrote:

Well, to be precise, we do not know whether it was a violation or not.

If he was 12,500 indicated, for the whole 3.5 hours, and the actual
altimeter setting was less than 29.92 along more that 30 minutes of the
route, then the "pressure altitude" would have been higher than 12,500 in
that portion, and it *would* be a violation. If the actual altimeter
setting was at or above 29.92 then it would *not* be a violation.


In either case, it would either be or not be a violation. I still don't
know what you mean by a "borderline" violation is.

I would always assume that, without information to the contrary, the pilot
was operating legally.

As I mentioned before, this does not imply that the operation was safe.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Icebound wrote:



I didn't say it was safe. I said that the FARs said it was safe.

The FARs don't say what is safe. The say what is legal.

"Ron Natalie" wrote in message
m...
Icebound wrote:



I didn't say it was safe. I said that the FARs said it was safe.

The FARs don't say what is safe. The say what is legal.

(Well... there was a little more to that quote than that...I think the next
part said that I meant that the FARs *implied* it was safe. But no
matter....)

What you say is absolutely true and I agree with you.

But I also agree that the FARs say it is legal (for the most part) because
those that have gone before us have shown it to be safe, or at the very
least, the least risky.

Cub Driver wrote in message . ..
In contrast, I'm not so comfortable with "deep breathing" to maintain a
higher oxygen saturation. In accomplishing this, you are almost
certainly decreasing the carbon dioxide in your blood, and that can make
you dizzy, lightheaded, anxious, and/or confused.

Thanks. That's a good description of what happens to tourist skiers
when they begin to hyperventilate at high altitudes.

(It was my impression though that they got there by panting rather
than by taking deep, measured breaths.)

I am off to Aspen next month. I'm going to try to forget this thread.
It's not good to be self-concious about one's breathing!


One of my instructors was of the opinion (and I susbscribe to it) that
as PIC oxygen at night above 10,000 feet and 12,000 during the day. No
exceptions.