Tire Problems? Some Facts from a Tire Engineer
- Thread starter tireman9
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mattpopp
Trouble Maker
Like I said, the temps can become extremely hot almost instantly during a landing. I have never heard of a successful landing without using brakes on a aircraft large enough to produce these kind of temps. With that being said braking is a function of landing and I assumed most understood that. Nowhere did I mention the heat came from the friction of the tires meeting the ground even though that is the beginning of the heat heating up.
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scottyb
Well-known member
Anyone had any experience with Michelin LTX M/S2 tires on their units? Talked to a dealer and this is what they recommend, said the Michelin Ribs were better but for $86.00 more per tire might be an over kill. Just wondering? Thanks
I run LTX A/T2's on my pickups and they are very good tires that last 50% longer than any other tire I have ran. I thought that the LTX M/S2 has a more agressive tread, and the M/S indicates "Mud and Snow". The difference is, the XPS Ribs are a commercial LT and have a full steel casing.
NWILSON
Kentucky Chapter Leaders - retired
You guys are trying to over simplify your arguments!
On some large aircraft there is a published taxi distance limit due to the amount of heat generated by sidewall flex....one source of heat.
On landing there is certainly some heat generated during "wheel spinup" on touchdown as well as sidewall flex during rollout. Remember that the aircraft is far lighter on landing than takeoff due to fuel burn-off ( 300,000 lbs or more on a longhaul 747 flight). The sidewall issue is significantly less on landing. You can easily put your hand on the tire after landing and taxi. It's warm but certainly not hot.
The other source of heat on landing is, as previously mentioned, braking. The brake assembly is mounted within the backside of the wheel. Heat from the brakes is transferred to the wheel. It's not the temperature of the tire that causes the fuse plug to melt but, rather, the wheel itself. This prevents the tire temp from getting to the point where the tire may burst whether from elevated pressure or melting of the tire itself.
The brake energy charts come into play most often after an aborted takeoff 777 aborted takeoff. The aircraft is heavy and maximum braking is used generating a LOT of heat. You can see in the video that they can get red hot. On normal landings it's not uncommon to not apply brakes til the aircraft has slowed to near taxi speed. Modern thrust reversers are extremely effective thereby reducing the need for brakes unless landing on a shorter runway.
Runway distance requirements are not predicated on the use of reverse thrust...it's a bonus. Since there is no way to account for how much or how little reverse thrust was used the brake energy charts assume brake use only. Frequently the brakes will be cool when the charts say additional time is required before the next takeoff.
As to the use of pure nitrogen in aircraft tires....it is less subject to pressure fluctuations at the wide range of normal operating temperatures experienced. Tire pressures on jet aircraft run from 150-200psi depending on the aircraft. Lack of moisture in nitrogen is also a factor but since a vacuum isn't drawn in the tires prior to inflation there is still a small amount of moisture from the ambient air.
I didn't mean to turn this into a Popular Science article. It just seemed like there were some gaps in the information that would make it difficult to understand for those not familiar with aircraft.
NWILSON thanks for taking the time to accurately explain this much better then I did. I'm one of those who prefers using reverse thrust over normal braking until the aircraft is slowed down. From the tech articles I have read it's the moisture that causes the pressure fluctuations otherwise dry air and Nitrogen will produce nearly the same results. However, 14 CFR 25.733 (e) does require the use of Nitrogen or other inert gas in any wheel with brakes on aircraft over 75000 lbs unless it can be shown that the tire liner will not produce a volatile gas when heated or that means are provided to prevent the tire temperatures from reaching unsafe levels.
Sorry about that. I'm an Airframe & Powerplant mechanic with Inspection Authorization, Airline Transport Pilot, former test pilot and I've worked for the FAA for the last 12+ years so it's pretty easy to get me started down the aviation path.
dave10a
Well-known member
I am the guilty one for mentioning aircraft and race cars tire using nitrogen. I only did that as a means to explain why nitrogen is not needed for the normal auto and RV tires. I am engineer by training experience and with very limited knowledge on air craft but a fair amount of knowledge on physics and chemistry. Sorry for bringing up the air craft auto scenario, but I thought real world applications and uses were in order because the nitrogen filling people use those examples for marketing their products to the public.
Grey Ghost
Well-known member
Well, as an update, I took the trailer to Discount Tire yesterday and they pulled the remaining tires on both sides (Power King...Tow Max) the tread on the three remaining tires was starting to separate so all four tires are being returned to Dynamic Tire, we will see what happens. Also have a bid of $1,600 to fix the 5ver we will see about that also. The Power King tires are dated 3810, 38th wk of 2010 and there was well over 6/32 left on the tread. Will keep you all up to date as this progresses.
Grey Ghost
Well-known member
I did speak to HL and they are the ones that directed me to TBC the distributor of the tire. TBC filed the claim for me with Dynamic and now dealing directly with Dynamic. Thanks for the suggestion!!
I too have lost three Towmax's on my 2012 Cyclone 3800 T/H and want to go with a more reliable tire. Towing at 18k # and cruising at 70-75mph in the Texas heat, I'm looking at the Sailun S637's and the Michelin XPS ribs...any thoughts on these two tires and any recommendations on a tire to run at these weights and speeds??
WOW! 70/75 MPH. you are over speed rating for you tires. If a tire problem happens at that speed bad things happen.
Take it easy guys, I realize that I'm "exceeding" the tires' recommended speed rating. I personally don't think that alone would cause three of them to disintegrate, but who knows. What I'm interested in and am asking for your opinions om, is a recommendation on a tire that will allow me to run at 70-75mph at these weights. Thanks
Slept like a baby last night!! After all the tire horror stories I have been reading on the TowMax, etc. tires ... and losing sleep over it ... I called in on my 2014 Big Horn 3685RL being built at the factory and asked them to upgrade to the Goodyear G614's. DONE. Although rated for 75MPH, this is one guy that stays at a SAFE 60-63 anyway. What's the hurray ... I'm retired ... and like saving gas too!
G Rated Tires + TPMS = Zzzzzzzzzzzzzzz
G Rated Tires + TPMS = Zzzzzzzzzzzzzzz
danemayer
Well-known member
Tire experts say that it's internal heat that is the culprit behind most tire failures.
When a tire rated for 65 mph is run at 65 mph, it's able to dissipate heat as fast as it builds up (assuming that inflation and loading are within design specs). When it runs at 75 mph, it can't shed the heat fast enough and internal temperature climbs. At a certain point, the internal fibers are damaged by the high heat. The damage is said to be cumulative, and eventually the tire will fail.
If you want to run at 75 mph, get the Goodyear G614. At 110psi, it will support 3750# per tire and it's rated up to 75 mph. You'll need wheels also rated up to 110psi and space between axles is a consideration. The G614 probably has a larger outer diameter than your current tires (about 30.7" OD if I remember correctly).
Another thing to consider about 75 mph is the forces being applied to your trailer. I didn't do well in high school physics, but I seem to remember that Force = Mass * Velocity. When you go faster, every bump in the road has a greater force of impact on your trailer. The difference between 65 and 75 mph is 15% additional shock every time you hit a bump. I drive between 55 and 60 and my trailer gets banged around enough for my liking.
mattpopp
Trouble Maker
You need to go to a 17.5" setup. My Cooper RM160's are rated at 75mph with a weight rating of 4805lbs. It cost me $2k for a set of 4 wheels/tires
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mattpopp
Trouble Maker
That's a two fold situation. But not always true on a tire. A solid round object like a wagon wheel then yes. Tire can be forced to absorbed more impact at a higher speed vs a lower speed. Tires will also pass over a pot hole with less impact with higher speed vs lower speed. But this also depends on the dynamics of each particular tire.
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