AMURRAY

AMURRAY

Well Known Member
I was surfing through the forums tonight a came across a post about nitrogen in aircraft tires. No I don't think you need to put nitrogen into GA aircraft tires. But I do think nitrogen has many uses. I do own a small nitrogen bottle. I couldn't tell you how many cubic feet is is but it is about 18 inches tall. Nitrogen is a dry and stable gas and has many uses. First of all the small bottle is very portable. I admit that I have hauled it out to the back yard to fill the tire in the wheel barrow. I do think it is necessary in jets. The tires go from freezing cold to to very hot in a split second. Not a good environment for moisture or an unstable gas. Get some moisture in a line, let say a static line. Disconnect it and blow it out with some nitrogen and it will dry it out in a big hurry. Also being a A&P it is indispensable for working on vapor cycle air conditionings. A great way to check for a leak in an AC system is to pump it up with nitrogen (200-300 PSI) and check for leaks with soapy water. You can't do that with shop air, plus the moisture would contaminate the system. The 2000 PSI bottle last a long time for me. I say I exchange it about every six months. It cost 12 bucks. Spruce and ATS advertise these expensive nitrogen rigs. They are not necessary. I bought the cheapest nitrogen regulator I could find and used a regular air hose quick disconnect on the regulator. I have a short air hose dedicated to nitrogen. It is easier for me to bring the nitrogen to the airplane than bringing the airplane to the shop air.
Aaron
 
Hummmmmm

All this can be avoided if one remembers to exchange the winter air for summer air when the weather gets warmer.
 
captainron said:
I just use 78% nitrogen. It's free-sort of.
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:D:D:D:p


I like the 78% also, I've never run out even once, honest. My tank is very large and round. It doesn't transport well but I have many outlets that can almost always be reached. It's contaminated with carbon based life forms but they rarely get into the tires so it isn't an issue very often.

Okay, I'm done
 
AMURRAY; said:
<with lots of snips>No I don't think you need to put nitrogen into GA aircraft tires. I do think it is necessary in jets.
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My understanding is that a completely dry gas is used in aircraft tires exposed to freezing temps so they don't get a chunk of ice inside them, unbalancing the tire on landing. Otherwise there's no need for N2 in our tires.
 
grantcarruthers said:
:D:D:D:p


I like the 78% also, I've never run out even once, honest. My tank is very large and round. It doesn't transport well but I have many outlets that can almost always be reached. It's contaminated with carbon based life forms but they rarely get into the tires so it isn't an issue very often.

Okay, I'm done
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Did you just pull that one out of thin air?
 
Glad to see people actually cutting up a little in here - it's like a breath of fresh air. :D
 
Just a side note. Nitrogen is required in aircraft by AD note because of a brake fire on take off on a transport aircraft. The gear was retracted and the fire caused the tires to explode in the wheel well and because they were filled with 78% nitrogen and 22% O2, exploded and killed all on board. I will try and come up with something funny later..:eek:
 
The molecules

Seems like I read somewhere that nitrogen molecules are larger than oxygen molecules and as a result, your tires will stay inflated to the proper pressure longer than with regular atmosphere.
If so, another plus.
 
Not really

sf3543 said:
Seems like I read somewhere that nitrogen molecules are larger than oxygen molecules...
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tableofelements.gif
 
Yes really

See http://www.composite-agency.com/cases/Pure_nitrogen_in_tyres.pdf
for an authoritative analysis.

A few other points:
Bottled nitrogen is dry, so you don't have water vapor and oxygen corroding things.
The water in the tires can undergo phase changes (i.e. liquid to gas) with seasonal temperature changes that will cause proportionally greater pressure changes than dry gas.

Still, if you check your tires often nitrogen fills probably aren't worth it. :rolleyes:
 
Nitrogen, Oxygen in Elastomers & Composites

Ted, thanks for the useful reference.

You may also take a look at their forum community for mechanical-chemical properties of elastomers, polymers & composites materials, applied - among others - in all sorts of aerospace applications.

reference:

http://www.composite-agency.com/forum.htm

Kind Regards,
John Stuart
 
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