More Tire Questions

PilotRPI

PilotRPI

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PilotRPI
1961 Cessna 172 B

Going to buy some Air Hawk tires. The mechanic recommended I go with 6 ply instead of 4 ply. Since the POH states 4 ply, is all I need a logbook entry for a minor alteration, or do I need something else to switch to 6 ply?

I am ordering through Desser. People have mentioned "leak proof/resistant" tubes, but the names all make them sound like that. What tubes, specifically, would you recommend? Something below or other?

Michelin Airstop $64
Aero Classic Leak Guard $55
Aero Classic Heavy Duty Natural Rubber $80
Aero Classic Inner Tube $55

Thanks!
 
Dessers retreads are FAR better then any tire on the market.. If they have your size, I would get them...

As for tubes... For some reason I never have air leak issues with any brand on my experimental.. The kit came with generic tubes from Gemplers.. I have to add about 1-2 psi once a year.. Far better then FAA approved crap..:mad2:
 
When I was running the maintenance for a flight school I never had much luck with Air Hawk tires. They're the old McCreary tire being sold under Specialty Tires of America label and they had, or at least did have, rather thin carcasses and a short life to match. Their tailwheel tires were hopeless, being nothing better than a Chinese handcart tire. I started using Condor tires (made by Michelin) that cost no more and lasted far better. Goodyears are even better--they seem to age slower--but in the flight school business they wear out long before UV and ozone get them.

As far as plies goes, a "6-Ply" tire is often just a four-ply tire with a six-ply rating. The plies were originally cotton or linen and have been replaced with stronger stuff like nylon, allowing the tire to have a higher rating than the actual installed number of plies.

For tailwheel tires, this one does the trick:

3224A.png


See this: http://www.supercub.org/forum/showthread.php?36129-Tailwheel-Tire-Wear-amp-Pressure
 
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N801BH said:
Dessers retreads are FAR better then any tire on the market.. If they have your size, I would get them...

As for tubes... For some reason I never have air leak issues with any brand on my experimental.. The kit came with generic tubes from Gemplers.. I have to add about 1-2 psi once a year.. Far better then FAA approved crap..:mad2:
Click to expand...

I have a pair of 600-6 Dresser Monster Retreads on the plane that are nearly new. They are coming off next week and will be replace with Airhawk 6-ply's. The Monster Retreads wear like iron, but they are very heavy and the pair I have will not balance. My A&P says I'm not alone not being able to balance them.
 
Old Geek said:
I have a pair of 600-6 Dresser Monster Retreads on the plane that are nearly new. They are coming off next week and will be replace with Airhawk 6-ply's. The Monster Retreads wear like iron, but they are very heavy and the pair I have will not balance. My A&P says I'm not alone not being able to balance them.
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Interesting.... My DESSERS were out of balance mainly because the tread is so thick.. But one pass on the balancer showed the light side. I added weights and they are still perfect....
What could possibly change during the life of the tire ?:dunno:..

Unless you land with the brakes locked and flat spot them...:idea:
 
N801BH said:
Interesting.... My DESSERS were out of balance mainly because the tread is so thick.. But one pass on the balancer showed the light side. I added weights and they are still perfect....
What could possibly change during the life of the tire ?:dunno:..

Unless you land with the brakes locked and flat spot them...:idea:
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Nope, not flat spotted. Too far out of balance from the factory.
 
you might want to look in to Desser Elite retreads on Goodyear or Michelin cores.
they are very very good
 
We run Airhawks w/ Michelin Airstop tubes all around and been pleased. Doesnt break the bank either. C172H
 
Old Geek said:
Nope, not flat spotted. Too far out of balance from the factory.
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I've heard of this before, but I'm also told that they'll swap them out for new ones if you call them. Maybe that's not the case?

My Dessers are at least ten years old and have about 1200 hours and likely the same number of landing on them. Still going strong.

patrick wentworth said:
you might want to look in to Desser Elite retreads on Goodyear or Michelin cores.
they are very very good
Click to expand...

Hmmm...you used to be able to spec the brand of carcass you wanted...if they had them then that's what you'd get. This makes it sound like they're now "up charging" for Michelin or Goodyear. That's a bit disappointing if true.
 
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What about going to a 6 ply when 4 is in the poh? Anything special I have to do there? Should I even do that?
 
From another forum (accuracy not investigated):

Technically and legally speaking, if the tire listed in the TCDS is not the one on the airplane, it is not a legal substitute. I believe that when it comes right down to it, this can be documented as a "minor" alteration with just a simple log entry...
Click to expand...
 
I think you're overthinking this a little.

Just get whatever the best package deal spruce has going on is
 
Do six-ply tires offer any advantage over four-ply? If you land hard enough to blow a four-ply, you've probably broken something else too. Only advantage I can see is a bit more material for a nail or whatever to go through before it gets to your tube. How much do six-ply tires weigh vs. four-plys?
 
JohnAJohnson said:
Do six-ply tires offer any advantage over four-ply? If you land hard enough to blow a four-ply, you've probably broken something else too. Only advantage I can see is a bit more material for a nail or whatever to go through before it gets to your tube. How much do six-ply tires weigh vs. four-plys?
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It's more a speed rating than anything else. As was mentioned earlier, a six ply rating doesn't necessarily mean there are more layers of rubber than a four ply tire. Weights vary; I've seen four ply tires that weigh the same or more than some six ply.
 
JohnAJohnson said:
Do six-ply tires offer any advantage over four-ply? If you land hard enough to blow a four-ply, you've probably broken something else too. Only advantage I can see is a bit more material for a nail or whatever to go through before it gets to your tube. How much do six-ply tires weigh vs. four-plys?
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From what I remember looking a couple months ago, you have more (and cheaper) choices going with a 6 ply over a 4 ply, I don't think any of the retreads were 4 ply, they all started at 6 ply.

I went with 4 ply because that's what the manual called for. One less thing to worry about if I get ramp checked (if they would even look or care. Don't know, don't want to find out.)
 
timwinters said:
From another forum (accuracy not investigated):
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Your quote is wrong. The tire is a portion of the design of the aircraft. changing it requires the proper paper.
 
As an additional note: a piper engineer told me and an IA a while back that tires are part of the suspension system. Changing to a higher ply rating means stiffer tires, and it's a little harder on the suspension.
 
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That sure doesn't explain paperwork-only gross weight increase STC does it?

Most of those STCs are held by companies other than the OEM. These companies certainly didn't do exhaustive engineering on structures to get them either. If such engineering were required it would be cost prohibitive.


The best part? Pretty much any OEM engineered repair will have a disclaimer that says "this repair is applicable only to aircraftthat are unmodified or modified by OEM issued STCs and Service Bulletins. The installer must determine if this repair can be installed on the aircraft", or similar.
 
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So is going to 6 ply considered a "minor" alteration requiring just a logbook entry? Anyone here an A&P and actually know instead of guessing? I don't see it as significantly altering performance or handling characteristics, but I don't pretend to be an A&P.
 
bnt83 said:
That sure doesn't explain paperwork-only gross weight increase STC does it?
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Eh? The paperwork only gross weight increase isn't just paper, it reflects the analysis that the change meets the requirements for the aircraft flying at the increased weight. The Navion for example gets a "paperwork" only weight increase because they added stronger gear in later models and more HP and didn't bother to redo the flight testing at the time these aircraft were manufacturered though they subsequently qualified retroactively.

Most of those STCs are held by companies other than the OEM.
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If "other than the OEM" means "other than the type certificate holder," I would suspect they all are. The original manufacturer doesn't need an STC, they'll just make the addition to the TC data.
These companies certainly didn't do exhaustive engineering on structures to get them either. If such engineering were required it would be cost prohibitive.
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Exhaustive, no. But your aircraft wasn't "exhaustively" tested in original certification either. But sufficient to show compliance to the FAA's satisfaction, yes.
 
PilotRPI said:
So is going to 6 ply considered a "minor" alteration requiring just a logbook entry? Anyone here an A&P and actually know instead of guessing? I don't see it as significantly altering performance or handling characteristics, but I don't pretend to be an A&P.
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By definition your tire change isn't a major alteration.

I've used Air Hawks and still have a set or two. They're good tires. I prefer Goodyear tubes because I have little patience for low air pressure. Even with good tubes I add a little Stan's no-tube sealant. Any porosity is stopped. I never need to add air.

FAA Definitions begining with the letter M

Maintenance. Inspection, overhaul, repair, preservation, and the replacement of parts, but excludes preventive maintenance.

Major alteration. An alteration not listed in the aircraft, aircraft engine, or propeller specifications—

(1) That might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or

(2) That is not done according to accepted practices or cannot be done by elementary operations.

Major repair. A repair:

(1) That, if improperly done, might appreciably affect weight, balance, structural strength, performance, powerplant operation, flight characteristics, or other qualities affecting airworthiness; or

(2) That is not done according to accepted practices or cannot be done by elementary operations.


Minor Alteration. An alteration other than a major alteration.

Minor Repair. A repair other than a major repair.
Click to expand...
 
TUPilot said:
The OEM goes the path of least resistance whenever possible. In some cases, that means installing an STC they own during production. Normally this is because they bought the STC from someone and it is easier to keep using it than amend the TC, but I bet examples of such things can be found for a variety of reasons.
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There is always an exception isn't there?

I noticed a crap ton of Cessna Aircraft Company STCs in the database with a variety of addresses and figured that those are Cessna owned repair stations that did those, which would be separate from the airplane manufacturing division.
 
PilotRPI said:
Going to buy some Air Hawk tires. The mechanic recommended I go with 6 ply instead of 4 ply. Since the POH states 4 ply, is all I need a logbook entry for a minor alteration, or do I need something else to switch to 6 ply?

Thanks!
Click to expand...


Unless it was an option of some sort, I wouldn't install 6 ply tires...


What you and your inspector do is up to you.
 
It has been a problem for numerous owners of the Comanche aircraft. Stick to what's listed in the Type Certificate Data Sheet. An overzealous inspector grounded an aircraft because it was non-conforming. Also if the aircraft is ever sold out of this country and a type certificate conforming inspection is done, they may find it, and it will become an issue. There was an article in Aviation Consumer, I think it was with the help of Desser, about the ply ratings and the difference between the 4-ply and 6-ply tire ratings, and the bottom line was the difference was in the stamp used to make the mark... not the tire.
Happy Monster Retread user since 2005.
 
bnt83 said:
There is always an exception isn't there?

I noticed a crap ton of Cessna Aircraft Company STCs in the database with a variety of addresses and figured that those are Cessna owned repair stations that did those, which would be separate from the airplane manufacturing division.
Click to expand...

Yup... and sometimes the OEM partners with the STC holder and installs an STC they don't own on factory new aircraft (I think a few "options" on a new King Air are actually STC held by an independent company for example).

That said, I'm not aware of any of these STCs that have to do with the OP's tire plys, so my apologies for thread drift!
 
Old Geek said:
Nope, not flat spotted. Too far out of balance from the factory.
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Take 'em to the tire store, and get 'em trued. They'll remove several thousand miles of rubber, but the tires will last way longer that the rubber they removed.
 
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