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reset.it
28th Nov 2008, 09:18
where can I find information about the limitation using the tire on airbus 320 ????
I mean which is the limit of a thread ????
if a tire looks worn without theread is it safe to fly ??? dry rwy ? or wet ?? ssw rwy??
is there a different limitation??

who can help me to get all information about ?
thanks

Henry VIII
28th Nov 2008, 09:24
Ask to tech for their manual (AMM or similar name).
Additionally, if the company allows and train the crew to perform and sign the preflight, you shoud receive a paper procedure which includes your requested detail. I mean scratch extent and deep limit and so on.
As far as I know no different limitation for dry, wet, contaminated.

SNS3Guppy
28th Nov 2008, 10:38
Reset.it,

Do you mean a tire without tread, or a tire where the cord is showing? I can't speak specifically about Airbus, but in general tread isn't a deciding factor in tire replacement as it may be on an automobile. Most airline and large airplane manufacturers make use of retred or recap tires, and so long as the tire on the airplane isn't taken down below limitations for recapping, it can be operated. There's a lot of tire to lose before it becomes unsafe; you might be surprised just how thick they are.

Most operators won't ever let them go that far, but as a general rule the tire need not be replaced until cord or under-material is showing. Most operators will replace the tire or wheel assembly before that time as a preventative measure, however...it's far better to pull the wheel early, when one has a chance, than take a delay because one has no choice later, at a less convenient time.

Tires are consumables...there's really no need to let them go too far, especially if they're going to be recapped, anyway.

Swedish Steve
28th Nov 2008, 10:54
British CAA tyre wear limitations

http://www.caa.co.uk/docs/33/CAP455.PDF

In the absence of evidence of the safety of a lower limit for a particular aircraft/tyre/
operation combination, it is recommended that a tyre be withdrawn from service
when it is worn to such an extent that its wet runway performance would be seriously
impaired. This may be defined as when:
a) it is worn such that any groove has a depth of less than 2mm of tread for more than
one quarter of the tread circumference; or
b) at any place on the circumference the tread pattern is worn to a depth of less than
2mm across the whole width of the tread in contact with the runway.
NOTE: This is not a rigid definition and equivalence may be provided if, for example, tyre
wear is such that whilst one groove is less than 2mm all the others are 3mm or more

celtic mech
28th Nov 2008, 11:44
For an a320, the details needed are in the AMM 32-41-00-210-002
All info can be found there.

IFIX
28th Nov 2008, 14:16
Have a look here; http://www.goodyearaviation.com/img/pdf/inspection.pdf

Not make or model specific but it will give you a basic understanding.

james ozzie
29th Nov 2008, 20:05
As a pax waiting at the bottom of the steps, my travel companion noticed a flat spot with canvas showing on a main gear wheel. He was utterly horrifed and was reluctant to board the flight - in his mind, he was thinking of a car tyre. So maybe they should be changed for PR reasons? Or apply some boot polish...!!

Swedish Steve
30th Nov 2008, 18:39
my travel companion noticed a flat spot with canvas showing on a main gear wheel

There are two sides to this.
1. The canvas you can see is not the canvas under the tread. When an airliner tyre is worn to a slick there is still 4-5cm of rubber remaining. Nowadays there are two types of tyres, crossplies and radials. Crossplies are still the norm on older B737, B757 B767 etc. Radials are norm on all Airbus from A320 on and B777. In a radial tyre there are reinforcing cords in the tread that become exposed when the tyre is nearly worn.
2. Nearly all tyres are retreaded. Most airlines set standards so that the tyre is removed in a condition so that it is fit to retread. If it is let to wear too far then it will not be possible to retread.
Some tyres cannot be retreaded. So it is in the airlines interest to allow the tyres to wear further.
A bald tyre is no problem on a dry runway (Formula 1 are reintroducing slicks next season), but can cause problems in the wet.

james ozzie
30th Nov 2008, 18:54
Thanks Swedish Steve - I was quite comfortable with the canvas, for the reasons you describe. It was a scheduled flight in a 732. But my point was that it frightened a layman.