Why nitrogen?

on 9/16/2008 6:31 PM Peter Dohm said the following:
Ordinarily, I would just let this slide; but since the greenies have decided
that CO2 (which is nature's means of recycling oxygen) and O3 (which is
nature's cleanser of the atmosphere) are "pollutants" according to the
strange reasoning of their adled brains, I feel compelled to point out that
I suggested that the aircraft would be sheltered in a hangar--which would
protect the outsides of the tires from part of the damage. They still won't
last until the treads wear out, but it will help.

You're suggesting hangars are so airtight that CO2 and O3 are somehow
sealed away from the tires inside? The effect of O3 on tires is not
through increased UV or global warming. It's direct chemical interaction
with the polymer chains in the rubber compounds.

"Rich Ahrens" wrote in message
. net...
on 9/16/2008 6:31 PM Peter Dohm said the following:
Ordinarily, I would just let this slide; but since the greenies have
decided that CO2 (which is nature's means of recycling oxygen) and O3
(which is nature's cleanser of the atmosphere) are "pollutants" according
to the strange reasoning of their adled brains, I feel compelled to point
out that I suggested that the aircraft would be sheltered in a
hangar--which would protect the outsides of the tires from part of the
damage. They still won't last until the treads wear out, but it will
help.

You're suggesting hangars are so airtight that CO2 and O3 are somehow
sealed away from the tires inside? The effect of O3 on tires is not
through increased UV or global warming. It's direct chemical interaction
with the polymer chains in the rubber compounds.

Not at all. However, UV is supposedly a player in rubber deterioration.

There is not much you can do about O3, you'll just have to live with it.

on 9/16/2008 8:39 PM Peter Dohm said the following:
"Rich Ahrens" wrote in message
. net...
on 9/16/2008 6:31 PM Peter Dohm said the following:
Ordinarily, I would just let this slide; but since the greenies have
decided that CO2 (which is nature's means of recycling oxygen) and O3
(which is nature's cleanser of the atmosphere) are "pollutants" according
to the strange reasoning of their adled brains, I feel compelled to point
out that I suggested that the aircraft would be sheltered in a
hangar--which would protect the outsides of the tires from part of the
damage. They still won't last until the treads wear out, but it will
help.
You're suggesting hangars are so airtight that CO2 and O3 are somehow
sealed away from the tires inside? The effect of O3 on tires is not
through increased UV or global warming. It's direct chemical interaction
with the polymer chains in the rubber compounds.

Not at all. However, UV is supposedly a player in rubber deterioration.

Via a separate mechanism. That's why tires are made and/or treated with
ozone protection additives.

There is not much you can do about O3, you'll just have to live with it.

Bull****. Reduce the amount of hydrocarbon and nitrogen oxides emitted
by various sources and you reduce the amount of low-level ozone produced
by their interactions. I'm not talking about the ozone layer here. I
mean the air we're breathing at our level of the atmosphere.

"Peter Dohm" wrote in
:

In the case of light plane tires, I agree with you that really dry
air should work well enough to make the issue trivial. But, if
you need nitrogen for any other reason, it is the cheapest thing
that I know of in an L bottle or larger and using it in the tires
may be essentially free--because you may have to pay rental on the
tanks if they are not refilled at a prescribed interval.

My daughter is a Crew Chief on a C-130 Herc and said that Nitrogen is
used in the struts.

--

"Morgans" wrote in message
...

"Peter Dohm" wrote

It appears that they were lucky and the oxygen was'nt needed; but it does
remind me of some of the speculation surrunding the Paine Stewart case.
Two hypotheses around my local airport were that 1) the tank was
inadvertantly filled with nitrogen or 2) that someone misread the
labeling on the regulator on/off handle--which is counterintuitively
labeled with "on" or "off" and arrows pointing which direction to turn
the knob for the desired result. I don't recall whether the case was
ever fully resolved; but a lot of pilots found a couple of areas worthy
of their maximum vigilance!

Learjets don't use bottled oxygen; they have pressurized air from the
engines.

--
Jim in NC

Learjets do indeed use bottled oxygen and it is found in the nose bay area.
There is a thin capillary that runs into the cockpit to a pressure gauge.
The pressure gauge displays the pressure in the tank regardless of whether
the valve is turned on or off. The pressure in the tank can read full on
the ground but at low temperature at altitude will read several hundred
pounds less.

--

*H. Allen Smith*
WACO - We are all here, because we are not all there.

"Rich Ahrens" wrote in message
. net...
on 9/16/2008 8:39 PM Peter Dohm said the following:
"Rich Ahrens" wrote in message
. net...
on 9/16/2008 6:31 PM Peter Dohm said the following:
Ordinarily, I would just let this slide; but since the greenies have
decided that CO2 (which is nature's means of recycling oxygen) and O3
(which is nature's cleanser of the atmosphere) are "pollutants"
according to the strange reasoning of their adled brains, I feel
compelled to point out that I suggested that the aircraft would be
sheltered in a hangar--which would protect the outsides of the tires
from part of the damage. They still won't last until the treads wear
out, but it will help.
You're suggesting hangars are so airtight that CO2 and O3 are somehow
sealed away from the tires inside? The effect of O3 on tires is not
through increased UV or global warming. It's direct chemical interaction
with the polymer chains in the rubber compounds.

Not at all. However, UV is supposedly a player in rubber deterioration.

Via a separate mechanism. That's why tires are made and/or treated with
ozone protection additives.

There is not much you can do about O3, you'll just have to live with it.

Bull****. Reduce the amount of hydrocarbon and nitrogen oxides emitted by
various sources and you reduce the amount of low-level ozone produced by
their interactions. I'm not talking about the ozone layer here. I mean the
air we're breathing at our level of the atmosphere.

....and YOU are going to accomplish all of that for the good of your tires in
YOUR hangar...

WOW! I'm VERY impressed.

"Peter Dohm" wrote in message
. ..
"Rich Ahrens" wrote in message
. net...
on 9/16/2008 8:39 PM Peter Dohm said the following:
"Rich Ahrens" wrote in message
. net...
on 9/16/2008 6:31 PM Peter Dohm said the following:
Ordinarily, I would just let this slide; but since the greenies have
decided that CO2 (which is nature's means of recycling oxygen) and O3
(which is nature's cleanser of the atmosphere) are "pollutants"
according to the strange reasoning of their adled brains, I feel
compelled to point out that I suggested that the aircraft would be
sheltered in a hangar--which would protect the outsides of the tires
from part of the damage. They still won't last until the treads wear
out, but it will help.
You're suggesting hangars are so airtight that CO2 and O3 are somehow
sealed away from the tires inside? The effect of O3 on tires is not
through increased UV or global warming. It's direct chemical
interaction with the polymer chains in the rubber compounds.

Not at all. However, UV is supposedly a player in rubber deterioration.

Via a separate mechanism. That's why tires are made and/or treated with
ozone protection additives.

There is not much you can do about O3, you'll just have to live with it.

Bull****. Reduce the amount of hydrocarbon and nitrogen oxides emitted by
various sources and you reduce the amount of low-level ozone produced by
their interactions. I'm not talking about the ozone layer here. I mean
the air we're breathing at our level of the atmosphere.

...and YOU are going to accomplish all of that for the good of your tires
in YOUR hangar...

WOW! I'm VERY impressed.



Yeah! Me too!

"John Godwin" wrote in message
...
"Peter Dohm" wrote in
:

In the case of light plane tires, I agree with you that really dry
air should work well enough to make the issue trivial. But, if
you need nitrogen for any other reason, it is the cheapest thing
that I know of in an L bottle or larger and using it in the tires
may be essentially free--because you may have to pay rental on the
tanks if they are not refilled at a prescribed interval.

My daughter is a Crew Chief on a C-130 Herc and said that Nitrogen is
used in the struts.

--

I'm sure that they use nitrogen in the tires as well--even though they run
at less than half of the pressure of a lot of the heavy jets--it just makes
sense to use it when you have it available.

Getting back to the original subject of whether nitrogen behaves in a manner
more like an "ideal gas" than air, aside from the issue of reactivity, the
answer is yes--especially as pressure is increased and/or temperature is
decreased. Basically, it is relatively easy to have nitrogen that is
extremely dry because it it normally dispensed from the top of a very high
pressure storage bottle--with the result that nearly all of any water vapor
and/or CO2 that is in the bottle will be left in a condensed form at the
bottom of the bottle.

"Allen" wrote

Learjets do indeed use bottled oxygen and it is found in the nose bay
area. There is a thin capillary that runs into the cockpit to a pressure
gauge. The pressure gauge displays the pressure in the tank regardless of
whether the valve is turned on or off. The pressure in the tank can read
full on the ground but at low temperature at altitude will read several
hundred pounds less.

They do? For primary breathing air at altitude? Is there no cabin air
pressurization provided by bleed air from the engines?

I'm not doubting your word, just trying to understand. I thought all
bizjets used bleed air to pressurize the cabins.
--
Jim in NC

John Godwin wrote in news:Xns9B1BD7A3321FBAvSvcs@
208.49.82.60:

"Peter Dohm" wrote in
:

In the case of light plane tires, I agree with you that really dry
air should work well enough to make the issue trivial. But, if
you need nitrogen for any other reason, it is the cheapest thing
that I know of in an L bottle or larger and using it in the tires
may be essentially free--because you may have to pay rental on the
tanks if they are not refilled at a prescribed interval.

My daughter is a Crew Chief on a C-130 Herc and said that Nitrogen is
used in the struts.


Your daughter smokes cigars?



Bertie