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The tire air myth

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Old 09-23-05, 07:47 AM
  #26  
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My Girlfreind (a cellist) has to buy and extra seat for said cello when she wants to travel with it. It DOES NOT go in the cargo hold. Both she, and the insurance co. forbid it (Said cello is worth $10,000 +).

Sometimes, the airlines will balk at this - even when she's AT THE BOARDING GATE with the cello!

On a large enough plane, they have on-board storage lockers, so it's never a problem. On a smaller plane, she looses.

I would imagine trying this with a bike would be less effective. One risks loosing one's seat and/or leaving the bike behind at the last minute. Air prices being what they are I would not risk it.
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Old 09-23-05, 07:54 AM
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Originally Posted by ViperZ
The general rule is atmospheric pressure decreases by half for each 18,000-foot increase in altitude. So at 36,000 feet, the tire that was once at 110 psi at sea level could be high enough to blow it off the rim or pop a tube. Thats the Airline's concern.
Fortunately for the tire and the living beings that might be in that same cargo hold, airplanes are generally pressurized to simulate an altitute of approximately 8000 feet. At this reference level air pressure is approximately 11 psi. Not exactly a significant difference.
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Old 09-23-05, 08:01 AM
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Originally Posted by sunninho
Nope, you just have to ascend slowly, 10 seconds per 10 feet and then stop at 15 feet, waiting 3-5 minutes before you surface with the wheels.

That all depending on if you go into deco or not, then it is a 5 minute stop at 30 feet, then 20, then 15, then 10............so many variables, man, now I am afraid to pump up my bike tires
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Old 09-23-05, 08:17 AM
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Originally Posted by ^*^BATMAN^*^
That all depending on if you go into deco or not, then it is a 5 minute stop at 30 feet, then 20, then 15, then 10............so many variables, man, now I am afraid to pump up my bike tires
And have you tried pumping bicycle tires up to 110 psi while scuba diving? It's murder at 50 meters


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Old 09-23-05, 09:25 AM
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Originally Posted by Machka
So a question for the physics-minded among you ... why do some of the airlines recommend (and sometimes strongly encourage) me to let the air out of my tires when it doesn't seem to matter one way or the other?
The physics is simple. An inflated tire has the potential to go "bang", and airlines passengers get nervous whenever something on board goes "bang". I had my CO2 cartridges taken away once, and that was long before 9/11.
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Old 09-23-05, 09:32 AM
  #31  
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Originally Posted by silk
The cargo area is heated and presurized to the same leve the cabin you are sitting in. which is about the same presure as living in Denver, Col
I had a bag of potato chips blow up in the back seat of my car once on the way up to Pike's Peak so then as long as your tires don't have chips in them you should be fine.
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Old 09-23-05, 09:35 AM
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Originally Posted by bhh
I had a bag of potato chips blow up in the back seat of my car once on the way up to Pike's Peak so then as long as your tires don't have chips in them you should be fine.
That was probaly more Temperature dependent
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Old 09-24-05, 07:58 AM
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You should not bring something pressurized into a plane, IN CASE THERE IS A PROBLEM AND THEY LOSE PRESSSURE. If things go according to plan they won't lose pressure. Just because your tires don't blow off, don't think that a pressurized cargo hold means it's OK to have pressurized containers on the plane.

The airline knows that if there is a problem they may lose pressure in the cargo hold and even the cabin area. They don't need another problem when that happens, like exploding bike tires and CO2 cartridges when that happens. Therefore they want you to do the right thing and not have any thing that may be a POTENTIAIL problem.

If everything is done right you don't bring anything pressurized and they don't ever lose pressure in the plane. This is how it's supposed to be!~!

Do what the airline says. Don't think that it's OK to have pressurized stuff on the plane. Just because nothing happens on your trip. Don't think tires can not blow off just because it didn't happen to you.

That's a dangerous way to think about it. No airline employees around here?
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Old 09-24-05, 08:20 AM
  #34  
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Originally Posted by Machka
I have flown with my bicycle numerous times, over various distances, within my own country, and to other countries . . . and the one thing I am consistent about is .......

..... forgetting to let the air out of my tires!!


However, in all my travels I've yet to have something happen to the tires.


So a question for the physics-minded among you ... why do some of the airlines recommend (and sometimes strongly encourage) me to let the air out of my tires when it doesn't seem to matter one way or the other?


BECAUSE IT DOES MATTER... if the plane looses pressure in the cargo hold and the cabin they have enough problems without bike tires and spray cans exploding in the hold. The explosion could cause some kind of problem we can't imagine. The airline company can imagine it!

We don't bring something pressurized on the plane and they don't loose pressure in the plane. That's the deal, everybody has to cooperate. Things go wrong sometimes.

If you get on the same plane as I do and you don't bring CO2 cartridges in your luggage, I promise to pump up your tires after we get off the plane.
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Old 09-24-05, 02:26 PM
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Originally Posted by FastFreddy
I always let some air out of the tires – get them maybe at 80% of maximum rated pressure. That way they can probably take the increase in relative pressure if the cargo hold depressurizes – which, I believe, doesn’t happen that often.

If that were to happen, believe me, the flight would be having much much bigger problems. You'd hear about it on the national news. The pressure envelope of the aircraft is the entire main body, not just the passenger cabin.

And about the post where the poster's friend claimed to have two blown tires after flights, I'd say someone is making up some stories for their own entertainment.
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Old 09-24-05, 03:08 PM
  #36  
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https://www.pprune.org/forums/showthr...hreadid=188513

Interesting discussion of almost what we're talking about from a pilot's standpoint. Similar confusion, though.
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