Rubber used for PA28 tyres

[air1jwilkins1212]

I've searched on Google and Wikipedia to find the type of rubber used for the PA28's tyres but haven't had much luck. Could someone please tell me the name of the rubber used?

Regards

[TheOddOne]

Could someone please tell me the name of the rubber used?


Dunno, but it dissolves nicely in AVGAS when the fuel drain right above the tyre develops a leak. We lost a tyre to that a while ago...

Sorry not to be of more help.

TOO

[air1jwilkins1212]

Ouch. AVGAS can dissolve tyres?!

[stevef]

You're probably using Flight Custom or Condor tyres. A typical light aircraft tyre is manufactured from natural & synthetic rubbers, carbon, silica, steel, rayon and nylon. I'm not aware of any special name for the rubber itself.

Avgas/oil/hydraulic fluid certainly destroys tyres by causing localised swelling.

[oli,_the_original]

Have you been on the manufacturers website, it might say on there?

Just out of interest, why do you want to know as well?

[air1jwilkins1212]

Have you been on the manufacturers website, it might say on there?

Just out of interest, why do you want to know as well?

I've looked on Piper's website at the specification for the PA28 Warrior. It mentions 4 ply rating rubber for the nosewheel tyre: "Nose Wheel, 5.00 X 5 with Tube, 4 Ply Rating"

Is that such a thing/does that ring any bells?

I wanted to know because I'm a Physics A-level student and for my investigation I intend to look at the net force produced for a PA28 to reach its rotation speed. Before Christmas however, I need to do a pilot experiment. I'm doing coefficients of friction for different rubbers...hence the reason I need to know the rubber name!

Thanks

[Saab Dastard]

I think that you will find that the "4-ply rating" applies to the construction of the tyre carcass, not the rubber compound applied to the surface.

I may well be wrong, but I would be surprised if the tyre companies were particularly willing to divulge the precise formulation of their rubber compounds!

Although I suppose a competitor can just buy a tyre and do a chemical analysis...

Why not drop messrs. Dunlop and Michelin a mail with your questions?

SD

[Pilot DAR]

Air1,

You might find it useful to understand the "hardness" of the tire. I believe that this property would be expressed in durometers (spelling might be wrong). A car tire manufacturer would probably happliy tell you relative to car tires, as it is a characteristic which makes summer tires, and snow tires different. Once you understand this, the aircraft tires characteristics may make more sense. Hardness would equate to friction somehow. Aircraft tires are definately not all the same!

Piper will probably not be able to be of much help with this, as they buy tires, which conform to the "TSO" standard of design and construction.

I tried to paste in a link, but it won't work. Look on the FAA website for TSO C62e. It should explain a lot...

Cheers, Pilot DAR

[A and C]

I am sure that the rubber compound is different depending on the tyre maker.

I have two Cessna 152,s and one PA-28 and the main wheel tyre is the same fitted to both types of aircraft.
When I started leaseing aircraft I fitted the cheapest tyres that I could find, this was a mistake as the cheap tyres were being changed at each 50 hour check. After testing a range of tyres it was found that the Goodyear tyres lasted the longest being fully worn out and usualy just making the 200 hour mark, but occasionaly falling a little short of 200 hours.

Condor tyres would make 150 hours each time but no more.

The cost of the Condor tyre (just under twice that of the cheap tyre) and the fact that the time to change it was at a very predictable maintenance check made it the best value for money for my company.

The Goodyear is the best tyre from a technical point of veiw but the extra cost of the tyre and the cost of downtime when having to change a tyre between maintenance checks exceeds the value of the longer life of the tyre.

Both the Cessna's are doing a lot of landings as they are my basic trainers, the PA28 weighs more and so I would expect less life from them, this is in fact the case the tyres fitted to the PA28 still last about 150 hours but the landings are about 25% less than the Cessna's

This is a very long way of saying that the rubber used is different between manufacturers, most of the landings are on the same runway so the only vairiable is the rubber compound of the tyres.

[Sleeve Wing]

air1jw1212.
>I wanted to know because I'm a Physics A-level student and for my investigation I intend to look at the net force produced for a PA28 to reach its rotation speed. Before Christmas however, I need to do a pilot experiment. I'm doing coefficients of friction for different rubbers...hence the reason I need to know the rubber name! <
Good luck with the dissertation. I was in the business some forty years ago and suggest that the subject you're dealing with can be quite complicated.
As many of the previous replies have offered, there are so many factors involved.
First of all, an aircraft tyre is designed to take impact before wear.
Secondly, it must be oil/fuel resistant. Hence use of neoprene or butane rubbers.(synthetics)
Thirdly, because a tyre flexes, it produces heat of its own besides heat produced by outside influences eg. hot sun, hot runways, heavy aircraft/ long takeoff runs, brake heat transfer etc.
Another major consideration is the total weight of the actual tyres.
Heat is the BIG problem as this will cause rapid deterioration of the tyre's ability to perform its job, both in frictional properties ie. braking, and in its own inherent distortion resistance/carcase failure.
Ply ratings relate to the fabric content of a tyre and are based on equivalent strength cotton fabric not the actual number of synthetic fabric plies in the tyre. Thus there are less layers of fabric than the rating suggests - another way of reducing the internal heat build up.
Friction coefficients are paramount with aircraft tyres and these are enabled to varying degrees by the 'formula' that the compounder develops.
He is the rubber technologist, usually a guy of degree level, who decides how much carbon black, antioxident, filler, liquid components etc. are milled into the masticated raw base rubber to produce the physical properties he needs to fulfil the tyre requirement..
As suggested, you should get in touch with the major manufacturers, Dunlop, Goodyear, Firestone, Michelin, Bridgestone. They will obviously not divulge specific compound data but should be able to help with basic aero tyre construction, and particularly physical and performance testing. Think of the problems with 1) Concorde ( High ground speeds) and 2)Airbus A380 (Huge weight problems) for example.
Just as a matter of interest, did you know that a large number of aircraft run on remoulds, purely an indication of wear in relation to carcase life !?
Rgds, Sleeve.
PS. Pls,guys, don't get me involved in any further discussion on tyre design queries. It would take a book ! :ok:

[BackPacker]

I wanted to know because I'm a Physics A-level student and for my investigation I intend to look at the net force produced for a PA28 to reach its rotation speed. Before Christmas however, I need to do a pilot experiment. I'm doing coefficients of friction for different rubbers...hence the reason I need to know the rubber name!

Is this a dissertation that's supposed to advance humankind, or is it a dissertation that is just going to prove to your teachers that you can write?

Not being demeaning, but if your dissertation is of the first kind, with the eventual aim of being published somehow somewhere, then tyre manufacturers will take an interest in it, and you might get access to their research labs under a non-disclosure agreement of some sort. You can get all sorts of data, get access to test rigs, pick the brains of the specialists in rubber compounds etc. Perhaps they even let you make up your own compounds and run tests against that!

If it's the second kind of dissertation, well, as others have said, just ask for some representative numbers and base your work on that. I've done a load of these dissertations and I know that a teacher doesn't care for very high precision numbers. Even if you base your paper on made-up numbers (not suggesting you should), the teacher should be more interested in the way you present your case, your writing style, identifying facts from assumptions from wild guesses, logical reasoning, that sort of thing.

(Note - I'm not from the UK so I have no idea what level a "Physics A-level student" is at.)

[smarthawke]

There's an article in the latest Today's Pilot all about aircraft tyres.

The ply rating used to be about the number of layers or 'plies' but these days is an indication of strength.

We use Michelin tyres on our fleet of Warriors operating from tarmac. On average these are lasting 500 hrs of PPL training and hire.

[Saab Dastard]

Backpacker,

I have no idea what level a "Physics A-level student" is at

This would be penultimate or final school year. So I guess the category would be the latter. :)

SD

[A and C]

I think that as Smarthawke's fleet is using the same tyres the lower use rate is probably due to a number of factors.

The airfield that his fleet fly from is considerably smaller than the airfield that my aircraft fly from this increses the amount of taxi time, we have no grass runway and some of the time Smarthawke's aircraft use the grass.

Unfortunatly smarthawke's airfield has a large number of NIMBY's that have forced a large circuit apon then making 5 landings per hour the norm, we have a very tight circuit making 14 landings per hour the average for circuit details.

I think that the large circuits forced on airfields are part of the reason that PPL students take so long to go solo these days, I don't think that the number of landings to solo has increased at all.

[Andy_RR]

If aircraft tyres are anything like automotive tyres, then you will find that the friction coefficient will reduce with increasing load. The tyre friction -v- normal loading will not be a straight line, but a curve.

Sorry to complicate your life.

BTW, this is the reason that lowering the CoG and widening the track of racing cars is beneficial as it more evenly distributes the load between the sides of the car during cornering, thereby increasing the total traction available.

A

[India Four Two]

air1jwilkins1212

I'm doing coefficients of friction for different rubbersA classic example of "two nations separated by a common language"

Please don't make this statement in North America ;) I speak from personal experience!