Sponsor Message:
Aviation Technical / Operations Forum
My Starred Topics | Profile | New Topic | Forum Index | Help | Search 
Aircraft Tires  
User currently offlineLehpron From United States of America, joined Jul 2001, 7028 posts, RR: 21
Posted (13 years 5 months 3 days ago) and read 2405 times:

Are they filled with regular air or some cold gas to keep them from heating up when their used?

I've seen pix of bizjets that don't have main bogie doors, so do they burst in the pressure difference when the plane climbs?

When measuring pound-per-square-inch, how much of the tire is used for calculating?



The meaning of life is curiosity; we were put on this planet to explore opportunities.
7 replies: All unread, jump to last
 
User currently offlineKlaus From Germany, joined Jul 2001, 21521 posts, RR: 53
Reply 1, posted (13 years 5 months 2 days 18 hours ago) and read 2315 times:

Any mechanics correct me where I´m wrong. But since none has answered yet, I´ll try:

Lehpron: Are they filled with regular air or some cold gas to keep them from heating up when their used?

The initial temperature of the gas isn´t relevant as it adapts to the environment´s temperature anyway.

As far as I know, some airlines are using nitrogen to fill their tyres because it has better long-term properties and is also better on temperature changes. (I don´t remember the details very well, here.)
Other than that, conditioned air would be used, as far as I know.

Lehpron: I've seen pix of bizjets that don't have main bogie doors, so do they burst in the pressure difference when the plane climbs?

No. The gear well doors are not airtight. They are only there for aerodynamic purposes.
Even if the plane would fly to outer space, the pressure difference would only be one athmosphere while the normal operating pressure of the tyres is several times that. (I might be wrong here, but I believe even the gear wells of the space shuttle are not pressurized.)

Lehpron: When measuring pound-per-square-inch, how much of the tire is used for calculating?

I´m metric, so I can´t tell for sure...  Wink/being sarcastic
But the pressure within the tyre is distributed evenly over the entire inner surface. So the pressure would be measured through the valve as it´s done for a car.


User currently offlineWestern727 From United States of America, joined Jan 2007, 753 posts, RR: 4
Reply 2, posted (13 years 5 months 2 days 17 hours ago) and read 2298 times:


Several airliners don't have "bogie" doors. The Boeing 737, and Embrarer EMB-145 are two that immediatly come to mind.



Jack @ AUS
User currently offlineNKP S2 From United States of America, joined Dec 1999, 1714 posts, RR: 5
Reply 3, posted (13 years 5 months 2 days 16 hours ago) and read 2289 times:

Tires are filled with nitrogen. 17 years in the business from corporate to widebodies, never used anything else but n2. Biggest reason is the lack of moisture as opposed to "shop air".Do not forget that while atmospheric pressure may be lower at altitude ( relative to the tires ), the temperature is much lower. Temperature, whether high or low has large effect on tire pressure. Most tire pressure limits are given fr an average 70F or so day.Whether pneumatic or hydraulics, a given pressure will be constant anywhere within the pressure vessel...be it a tire/wheel assy, 150 feet of hydrauic lines, or pneumatc ducting. You get the idea.

User currently offlineA330 From Belgium, joined May 1999, 649 posts, RR: 7
Reply 4, posted (13 years 5 months 2 days 15 hours ago) and read 2277 times:

Ok,
There is a lot to say about tires, but I will try to write down some more basic things.

First of all, all Aircraft with a MTOMA (Max. T/O Mass Allowed) of more than 5700kg., must have tires filled with Nitrogen. Below this, the use of Air is allowed.
Most tires nowadays are of the tubeless design which have a sealing layer inside.
The tire pressure on Airliners is mostly around 200PSI.
If pressure in a tire gets too high, mostly due to an increase in temperature (rejected T/O, ...), the tires will deflate completely due to so called ''fusible plugs''. These plugs will prevent the tire to burst. The temp. where the plugs will work is mostly around 150deg. Celcius.
Most tires are of a ribbed tire tread pattern, but small planes used on soft fields also use diamond pattern treads!
The tires are measured for strength by their ''ply ratings'', which is an equivalent number about the strenght of the construction ( it used to be the number of layers of cotton between the rubber); the ''tire speed ratings'' which designate the max. speed to operate the tire (ground speed of course).

Remember, if approaching a hot tire, always approach from the front or rear, NEVER from the side, because this is the weakest part of the tire.

A330



Shiek!
User currently offlineBuff From Australia, joined Mar 2007, 0 posts, RR: 1
Reply 5, posted (13 years 5 months 2 days 9 hours ago) and read 2251 times:

If I'm not mistaken, N2 is also non-flammable. "Air" would aid combustion in the event of a wheel/tire fire.

Best Regards,

Buff

PS I think there is material in the Archive on this subject.


User currently offlineRams777 From United Kingdom, joined Aug 2001, 58 posts, RR: 0
Reply 6, posted (13 years 4 months 4 weeks 1 day 17 hours ago) and read 2215 times:

3 Days ago i was on an Egypt Air Boeing747-300 and while the plane was taxing to the runway, the guy sitting next to me was talking on his mobile phone. Do you think the Pilots cared? obviously they knew it was happening but did nothing. This could have cause something to a larger scale.

User currently offlineNotar520AC From United States of America, joined Jul 2001, 1606 posts, RR: 4
Reply 7, posted (13 years 4 months 3 weeks 6 hours ago) and read 2159 times:

What does that have to do with tires?


BMW - The Ultimate Driving Machine
Top Of Page
Forum Index

Reply To This Topic Aircraft Tires
Username:
No username? Sign up now!
Password: 


Forgot Password? Be reminded.
Remember me on this computer (uses cookies)
  • Tech/Ops related posts only!
  • Not Tech/Ops related? Use the other forums
  • No adverts of any kind. This includes web pages.
  • No hostile language or criticizing of others.
  • Do not post copyright protected material.
  • Use relevant and describing topics.
  • Check if your post already been discussed.
  • Check your spelling!
  • DETAILED RULES
Add Images Add SmiliesPosting Help

Please check your spelling (press "Check Spelling" above)


Similar topics:More similar topics...
Nitrogen In Aircraft Tires posted Sat Oct 4 2003 07:48:54 by VS340
What's The Other Function Of Aircraft Tires? posted Thu Feb 13 2003 13:52:32 by Tsufang@ci
About The Retreading Of Aircraft Tires posted Tue Aug 13 2002 01:43:31 by Bio15
Aircraft Tires posted Sun Jul 29 2001 10:34:34 by Lehpron
Aircraft Type Printed On Tires? posted Mon Aug 23 2004 05:01:42 by Trickijedi
Snow Tires On Commercial Aircraft? posted Thu Jan 29 2004 04:15:56 by KingGeo3
Stored/Parked Aircraft With Flaps Extended? posted Mon Nov 13 2006 04:59:56 by Warreng24
Do Aircraft Controls Have To Be "calibrated"? posted Sun Nov 12 2006 21:26:09 by Jamesbuk
Tell Me About Aircraft Batteries.. posted Sun Nov 12 2006 06:04:24 by N234NW
Aircraft Fasteners - Update posted Thu Nov 9 2006 13:48:52 by HAWK21M

Sponsor Message:
Printer friendly format