Ryefly
Posts: 1324
Joined: Wed Jun 21, 2000 7:56 am

Aircraft Tire Questions

Fri Oct 06, 2000 2:47 pm

Hi!

As you know tires have been in the news lately, so that got me thinking...

Who makes the tires for aircraft?

How long does a tire generally last for a airplane like say a 757?

I have been on a couple flights where a tire needed replacing before we boarded. On one flight however we had already boarded and then an announcment from the Captain told us they need to change a tire but there was no need to get back off. I thought that was strange. Are they allowed to change a tire with passengers onboard? I guess so because they did, but I was just checking how often that happens.

 
UAL Bagsmasher
Posts: 1839
Joined: Wed Sep 08, 1999 12:52 pm

RE: Aircraft Tire Questions

Fri Oct 06, 2000 2:51 pm

Yes..they frquently change tires while PAx are boarding and Ramp is loading the aircraft. The jacks they use are impressive. Some even have a hose that uses nitrogen from the valve stem of the tire being deflated to jack up the Bogey.
 
NKP S2
Posts: 1665
Joined: Mon Dec 20, 1999 3:16 am

RE: Aircraft Tire Questions

Fri Oct 06, 2000 3:16 pm

100 landings per tire is nominal, which of course can vary with conditions. R&Ring a tire with passengers board is no big deal as you are only raising a strut a few inches. The jacks are not as big as one would expect them to be, given the nature of their work...they're not much bigger than a good sized auto floor jack. They are hydraulic and can be pumped up manually using fast/hard or easy/slow pistons, but mostly an air operated piston..."shop" air, nitrogen from a cart or a jumper hose from the old tire is used. Using the "old" tire for an air source ( Nitrogen really ) saves a lot of work and is super efficient, and in any event the old tire must be deflated anyway before it is shipped back to the wheel/brake shop.
 
Ryefly
Posts: 1324
Joined: Wed Jun 21, 2000 7:56 am

RE: Aircraft Tire Questions

Fri Oct 06, 2000 3:31 pm

Thanks for the interesting info guys!
 
VC-10
Posts: 3546
Joined: Tue Oct 26, 1999 11:34 am

RE: Aircraft Tire Questions

Fri Oct 06, 2000 3:36 pm

NKP S2

The tyre has to be deflated before the hub nut is removed. If you do not you could end up "wearing" the hub half.

Another point is that the tyres are often re-moulded but this depends on the tyre being removed before the tyre carcass is damaged. Before being remoulded the tyre will undergo an X-ray examination to make sure there are no hidden defects.
 
crjmech
Posts: 257
Joined: Wed Jun 07, 2000 6:31 am

RE: Aircraft Tire Questions

Fri Oct 06, 2000 3:39 pm

Just a quick add-on to the previous (and excellent) posts. Most jacks raise the tires by compressing the strut. Since the jack isn't taking that much of the plane's weight and doesn't really lift it up, pax and bag loading can continue as normal.
Thou shalt mind thine altitude,lest the ground reach up and smite thee.
 
VC-10
Posts: 3546
Joined: Tue Oct 26, 1999 11:34 am

RE: Aircraft Tire Questions

Fri Oct 06, 2000 3:51 pm

Ned,

I cannot agree with your last post. If the strut is compressed a certain amount by the weight of the a/c how is the jack going to compress it further?

Incidentally, you can jack a 747 loaded to max taxi weight for a wheel change.
 
JT8DJET
Posts: 196
Joined: Fri Jul 07, 2000 12:28 am

RE: Aircraft Tire Questions

Fri Oct 06, 2000 11:02 pm

RyeFly, to answer your first question.
All the big tire manufactures make aircraft tires. The one's I see the most are Goodyear & Michelin, but I'm sure there are others. BF Goodrich has several wheel & brake shops through out the US.
 
crjmech
Posts: 257
Joined: Wed Jun 07, 2000 6:31 am

RE: Aircraft Tire Questions

Sat Oct 07, 2000 3:23 am

Curses! Foiled again! Correct as always, VC-10. But this leads me to a question- how high do you have to jack a large a/c in order to change a wheel assy.? Can this cause problems with the jetway and/or the baggage conveyor? I've never changed tires on an a/c at a jetway, or come to think of it, a large (Boeing/Airbus size) plane either. Just the regional-size birds.
Thou shalt mind thine altitude,lest the ground reach up and smite thee.
 
VC-10
Posts: 3546
Joined: Tue Oct 26, 1999 11:34 am

RE: Aircraft Tire Questions

Sat Oct 07, 2000 3:41 am

I would say about 7 inches. A large jet normally has a bogie for the main gear in which case when you jack it for a wheel change you pivot the bogie around the set of wheels that will be staying on the ground. You will lift the a/c to some extent but not as much as an a/c with single axle u/c.

Modern jetways are also self leveling so as the a/c goes up 2 or 3 inches so will the jetway
 
wilcharl
Posts: 1153
Joined: Sun Jun 25, 2000 11:19 am

RE: Aircraft Tire Questions

Sat Oct 07, 2000 3:58 am

Correct me if im wrong but Didnt BF Goodrich's A/C tire or tyre depending on what side of the pond you live on get bought out by Michelin who now slaps thier name on the tires. Ive seen Michelin AIR tires, Goodyear Flight Leaders, and i saw one tire that was a japanese made Bridgestone that was retreaded with a goodyear retread.. caught me kind of odd. Also I noticed that our old tires get retreaded with a really cheap atuomotive tread and get thrown on our jetways Intersting i thought and even more intersting is the company that services our jetway fills them with nitrogen not air just as if they were on a plane

 
JT8DJET
Posts: 196
Joined: Fri Jul 07, 2000 12:28 am

RE: Aircraft Tire Questions

Sat Oct 07, 2000 8:57 am

Wilcharl,
Yes, BFGoodrich sold the tire division to Michelin.
BFGoodrich Aerospace is a seperate company that, among other things, has several wheel & brake shops. They do tire retread & brake overhauls. The airline I use to work for had Goodyear supply the tires and BFGoodrich do the wheel build up.