Boeing tyres
 

Hi, lost a tyre the other day but it was just the tread section that came off. Are all large aircraft tyres re-treads or is it just my company being cheap?
Thanks

FREDA

There is absolutely no reason to worry about re-treads. It's a long time standard in industry.

regards

Most all are 'retreads' as you put it, generally allowed to be retreaded up to six times, (the current retread count is marked on the tyre sidewall); however there are some aeroplane types that do not have retreads.

See section 5 of this manual from Goodyear for information on the retreading procedure ----> http://www.goodyearaviation.com/reso...raftmanual.pdf

ttfn

The re-treaded tyres actually last longer than the new ones. Typically the tyres are re-treaded around five times depending on the condition of the carcase.

Regards,
BH.

Good info, thanks guys

FREDA

FREDA;

On your next walk around, look at the tires, the number of times it has been retreaded will be stamped on the edge of the retread. I have seen as high as R19, meaning that tire had been retreaded 19 times.

these tread separations happen on car and truck tyres that havent been retreaded, the cause cant be fully explained, sometimes they tyre doesnt go flat

If it's on a Boeing....its a TIRE :}:E

Now....if it lands in the UK it might be a Tyre :)






Sorry its a slow day and I was bored.

Well its a long jetlagged night for me, but a tyre (British invention) is still a tyre in English (English invention :} )


Ill give the Americans the aeroplane though.. not bad :ok:

(Cant say airplane, sounds like kid-speak :E )

Anyway, Ive got the info I needed, so thanks again

FREDA

FWIW the original English-English was tire, but in the late 18th century it gradually swapped over to tyre - Being an Aussie that is the only correct way to spell it for me.

Oh, and speaking of tyres, all my own work ..... ;)

http://www.billzilla.org/747tyre3.jpg

Lost a tyre on the takeoff roll, lost the other on the landing roll .... and indeed most of the wheels there as well.

Also, if it has green dots painted around the side wall near the tread, it's a re-mould. These are the ''Awl Vent Points'' where the air is sucked out of the tyre when the tread is moulded to the carcass.

18 Wheeler - just to be super-pedantic, you're almost right. However it started off as "tyre" in the 15th Century, became "tire" (which is how the colonials got hold of that spelling) in the 17th Century and then reverted to Tyre again in the early 19th century. Probably to disambiguate from the other meaning of tire - eg "to tire of a discussion about spelling".

Well its a long jetlagged night for me, but a tyre (British invention) is still a tyre in English (English invention)

FREDA

And just to be even more pedantic, the pneumatic tyre is a Scottish invention, and here's the intriguing story of the guy who really invented and patented it as UK Patent No 10990, curiously enough under the name of the "aerial wheel":
http://www.historic-uk.com/HistoryUK/Scotland-
History/RobertWilliamThomson.htm

Even more curiously, he is buried only a few yards from my parents.

Jack
(aka Jock)

Thank you, fellow pedants. :)

Landings...
 

And, interestingly (I think, anyway!), your company likely doesn't even 'buy' the tyre in the classic sense. Michelin, for examples, actually sells "landings (per tyre)" thus warrants how many landing cycles you'll get out of 'em, then they take 'em back and re-skin 'em.
So, in most cases in commercial aviation, you're actuality 'leasing' the tire (oops - tyre - I slipped:))

Awl holes are present on new tyres.

Much less impressive than that for me 18-Wheeler

http://i44.tinypic.com/21m9don.jpg

And Jock, thats why I used British rather than English.. being inclusive and all that :}

FREDA

Standard in the commercial tyre industry. Major city bus fleets in Britain, for example, have long had "tyre contracts", normally directly with the mainstream tyre manufacturer, where the supplier provides the tyres based on a contract price of so many pence per mile run. It transfers the risk to the supplier and encourages the development of products which last longer. In the larger operations the tyre fitters are employees of the tyre manufacturer rather than the operator's maintenance team.

Most throw treads are not manufacturer defects, often a result of a cut across a rib that usually is cut by running over a taxi light. The less wear you have the higher the centrifical force applied to the tread causing seperation.

The only limitation to the tire it's self in reguard to the 6 retread limit is time, as rubber get's old it deteriorates. Tires that are used more often are actually in better condition as the core rubber likes to bend and flex, it helps maintain it's properties.

In the picture above you can see several layers of cloth, each put down with a new retread. I would have no problem with landing on this tire, there are still many layers of rubber and carcass chord that maintain the actual tires integrity. This tire is actually safer than a new one with a cut in it from groove to groove. Thrown treads at high speeds can do alot of damage such as busting hydraulic lines but usually just beating the hell out of the flaps and gear door.

The image of the MLG with the tyre showing its plies - Had the recap of the tyre come off at a landing and it was wearing into the plies?

Or is that the result of a number of cycles?

Mike

Looks like the result of a BAAADDD remould to me.
If it was on a Russian aircraft it would be just worn in.
The Ruskies like to get a bit of value out of tyres.

I used to fly V bombers which had tyres which wore down to the threads as a matter of course. You wore off several layers of rubber and threads before the tyre needed replacing. They were however different to modern tyres, being inflated to 325 psi. The tyres usually looked horrible and I was told on countless occasions that the aircraft's tyres needed changing by people who didn't know how they worked.

My previous company told me that they had reduced the permitted number of retreads on the fleet from 12 to 6, after an analysis showed that the tyre use cost savings were being outstripped by the downtime on tyre tread failures.

Those to not appear to be "plies" to me in the structural sence. They appear to be the cloth wear indicator that is often layed over a portion of the last with a retread. It is often refered to as the first ply but has no real structural value.

I believe I am correct in saying there are usually 2 more layers of chord before the carcass chord which is red. Usually other than catastrophic failure the only way to see a carcass chord is with a deep cut. and there are plenty more layers of chord below it.

working on the widebodies from both airbus and boeing with 3 different tyre makes in use we've ended up down to a maximum of 3 retreads in the last few years due to failures. max used to be 5 . and this in a fleet with tyre pressure indication and a variety of different loads so nothing common with failures !