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SRQfoxtrot
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Tire-speed-limit exceedance

Tue Sep 22, 2020 3:07 am

According to this excellent article, https://www.boeing.com/commercial/aerom ... _04_1.html
"Boeing is receiving an increasing number of operator inquiries about tire speed limits being exceeded during takeoff. This does not appear to be a new issue. Rather, advanced data acquisition tools on modern airplanes have made operators more aware of tire speed exceedance events."

My question is have you pilots inadvertently experienced exceedance events when dispatched at or near the airplane’s tire speed limit? If so, what were the causes and the outcome?

(Apologies if this article has already been discussed}
 
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Starlionblue
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 6:31 am

These factors will drive up ground speed on the takeoff roll.
- Tailwind
- High temperature
- High density altitude
- High weight

Haven't seen it myself. We're normally well below the max tyre speeds.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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zeke
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 6:52 am

SRQfoxtrot wrote:
If so, what were the causes and the outcome?


The obvious reason to me would be incorrect rotation technique.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
Noshow
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 7:24 am

Or overloaded aircraft due to wrong standard weights for passengers and their baggage?
 
evanb
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 12:30 pm

Would the rated limits be somewhat lower than the actual limits to ensure that there is some operational margin of error/safety? E.g. rated to say 260 knots with testing showing tyre can tolerate 270 knots to reduce probability of failure at the margin?
 
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Starlionblue
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 1:51 pm

evanb wrote:
Would the rated limits be somewhat lower than the actual limits to ensure that there is some operational margin of error/safety? E.g. rated to say 260 knots with testing showing tyre can tolerate 270 knots to reduce probability of failure at the margin?


260 knots?!? What are you flying? A 1950s fighter jet? ;)
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
CosmicCruiser
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 3:12 pm

Ha! Maybe an F-104! The -11 had 206 kts best I remember. Never close except in the sim.
 
unimproved
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 4:11 pm

evanb wrote:
Would the rated limits be somewhat lower than the actual limits to ensure that there is some operational margin of error/safety? E.g. rated to say 260 knots with testing showing tyre can tolerate 270 knots to reduce probability of failure at the margin?

A tire could probably take double the rated speed before rapid unplanned disassembly starts. But it might be weakened on the inside so replacement is a precaution.
 
zuckie13
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 6:52 pm

Starlionblue wrote:
evanb wrote:
Would the rated limits be somewhat lower than the actual limits to ensure that there is some operational margin of error/safety? E.g. rated to say 260 knots with testing showing tyre can tolerate 270 knots to reduce probability of failure at the margin?


260 knots?!? What are you flying? A 1950s fighter jet? ;)


Well, is it that unreasonable really? Maybe someone can do the real math, but I'd figure the ground speed of say a 737 or A320 at a high altitude like La Paz at 13000+ feet might be up at 220ish knots ground speed based on my own horrible math. Figure you'd want some margin above that in the tires you use.
 
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flyingturtle
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 9:00 pm

You can't extend the flaps and you have to land... some... how...
Reading accident reports is what calms me down
 
AC320tech
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 9:37 pm

Ive read on here before that the A340-600 can do missions the 777-300ER cannot due to tire speed limitations on the 77W if the stars aligned properly.
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Tue Sep 22, 2020 10:03 pm

Tire over speeds are fairly common on the 737-900s in Denver on hot days at heavy weights; esp at Flaps 1. Typically it is caused by slower than necessary rotation rates (noted by Zeke). The tight tail strike limits on these a/c may induce it; a tire over speed (>195kts) is better than a tail strike 200% of the time.
 
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Starlionblue
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 12:49 am

CosmicCruiser wrote:
Ha! Maybe an F-104! The -11 had 206 kts best I remember. Never close except in the sim.


I remember a SlamClick saying.

"If they somehow built a runway that went all around the Earth along the equator, North American would design a fighter that needed it."
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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Acey559
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 6:46 am

Tire limit issues have been a near constant item of note in our quarterly fleet newsletters and recurrent training at my airline. The biggest offender is the 757-300 fleet running routes out to Hawaii from Denver in the summer.

As Zeke mentioned, FOQA data shows that improper rotation is the cause for nearly every incidence. The -300 is particularly susceptible because our takeoff speeds are already significantly increased to reduce the likelihood of a tail strike, so there’s limited margin for error to begin with. Add in a hot Denver afternoon and it’s unforgiving of improper technique, though we have had issues across all fleets, not only the 756.
 
evanb
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 7:19 am

Starlionblue wrote:
260 knots?!? What are you flying? A 1950s fighter jet? ;)


Haha ... I was trying to be a little ridiculous and provocative, but the original question stands (and been answered) in terms of the design limits and safety margins :-P
 
GalaxyFlyer
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 2:21 pm

Starlionblue wrote:
CosmicCruiser wrote:
Ha! Maybe an F-104! The -11 had 206 kts best I remember. Never close except in the sim.


I remember a SlamClick saying.

"If they somehow built a runway that went all around the Earth along the equator, North American would design a fighter that needed it."


Or Lockheed in this case. Or Republic (the Thud).
 
FriscoHeavy
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 3:39 pm

Certainly not directly related, but we flew on an AA 321 last week from DEN-DFW (short flight, lightly loaded) on a 'normal temp' day and I'll tell you what, I didn't think we'd get off the ground (semi-sarcasm). Now, I know it was a significantly reduced thrust take off, etc, but Lordy, it was one looooong take off roll. We truly used up near the entirety of runway 25.

I'd love to take off in a MTOW 737-900ER on a hot day!
Whatever
 
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dennypayne
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 4:54 pm

FriscoHeavy wrote:
I'd love to take off in a MTOW 737-900ER on a hot day!


I've been on plenty of full 739's ATL- SEA in the summer and it's not nearly as dramatic as a.net myth makes it out to be. Granted, not the same density altitude as DEN, but I think the stories of poor t/o performance on the 739 are heavily exaggerated.
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FriscoHeavy
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Re: Tire-speed-limit exceedance

Wed Sep 23, 2020 6:42 pm

dennypayne wrote:
FriscoHeavy wrote:
I'd love to take off in a MTOW 737-900ER on a hot day!


I've been on plenty of full 739's ATL- SEA in the summer and it's not nearly as dramatic as a.net myth makes it out to be. Granted, not the same density altitude as DEN, but I think the stories of poor t/o performance on the 739 are heavily exaggerated.


No doubt the performance limitations are greatly exaggerated. I agree with you.

However, it will still be fun to take off at MTOW from Denver's mile-high altitude when it's 100 degrees out :)
Whatever
 
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zeke
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 1:17 am

dennypayne wrote:
FriscoHeavy wrote:
I'd love to take off in a MTOW 737-900ER on a hot day!


I've been on plenty of full 739's ATL- SEA in the summer and it's not nearly as dramatic as a.net myth makes it out to be. Granted, not the same density altitude as DEN, but I think the stories of poor t/o performance on the 739 are heavily exaggerated.


I fail to see how being a passenger on an aircraft can be used as proof that an aircraft is not performance limited.

An 88 deg F day (average maximum temperature) in July out of ATL is still less than 4000 ft density altitude.

DEN has an elevation on 5431 ft, during summer has similar maximum temperature as ATL, the density altitude can easily reach 8500 ft.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
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dennypayne
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 3:42 am

zeke wrote:
dennypayne wrote:
FriscoHeavy wrote:
I'd love to take off in a MTOW 737-900ER on a hot day!


I've been on plenty of full 739's ATL- SEA in the summer and it's not nearly as dramatic as a.net myth makes it out to be. Granted, not the same density altitude as DEN, but I think the stories of poor t/o performance on the 739 are heavily exaggerated.


I fail to see how being a passenger on an aircraft can be used as proof that an aircraft is not performance limited.


I never claimed to be 'proving' anything, merely providing anecdotal evidence. I am certainly capable of noting t/o distances, observing that they correlate well with the same on other types in similar conditions, and concluding that some of the claims I've seen on this site regarding the 739 having notably worse performance than other types lack merit. No doubt it's performance limited to some degree, but not to the extent that some commenters here led me to believe before I experienced it for myself.
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CR1/2/7/9 D8S D93/4/5 DHC2/3/7/8 D28/38 EMB/EM2/ER3/D/4/E70/75/90
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Max Q
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 8:36 am

In the 727 days we’d get really familiar with both ends of the runway departing DEN in the summer
The best contribution to safety is a competent Pilot.


GGg
 
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flyingturtle
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 8:44 am

Following up to my own comment:

I remember somebody saying on this forum that a heavy MD-11 with flap problems will exceed its tire limits when landing.

But, of course, I don't remember who said it... and when. And where.
Reading accident reports is what calms me down
 
Chaostheory
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 11:05 am

744 was the biggest culprit where I work. Perhaps surprisingly, we've only had a handful of tyre overspeed instances on the 777.

No issue with the bus fleet and that includes the A321 ops out of Riyadh, Medina etc
 
blacksoviet
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 12:51 pm

Delta 777-200LRs have custom tires that allow more fuel to be carried at JNB. These tires allow Delta to fly straight to ATL without any fuel stop. Were these installed by Boeing at the factory?
 
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zeke
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 1:16 pm

dennypayne wrote:
I never claimed to be 'proving' anything, merely providing anecdotal evidence.


It is not evidence, look up what the word means

dennypayne wrote:
I am certainly capable of noting t/o distances, observing that they correlate well with the same on other types in similar conditions, and concluding that some of the claims I've seen on this site regarding the 739 having notably worse performance than other types lack merit. No doubt it's performance limited to some degree, but not to the extent that some commenters here led me to believe before I experienced it for myself.


A passenger has zero idea of the performance limits that are impacting an aircraft when sitting in the cabin.

Similarly, a spotter or even ATC would not be able to tell anything about the performance of an aircraft when observing it relative to other aircrafts takeoff path.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
FriscoHeavy
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Re: Tire-speed-limit exceedance

Thu Sep 24, 2020 3:09 pm

blacksoviet wrote:
Delta 777-200LRs have custom tires that allow more fuel to be carried at JNB. These tires allow Delta to fly straight to ATL without any fuel stop. Were these installed by Boeing at the factory?


The tires have a higher rated speed limit to allow more weight/payload, which in turn means needing a faster rotation speed. It's not about fuel load, but weight overall.

I don't know if they were installed by BA at the build or put on after market.
Whatever
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Fri Oct 02, 2020 12:42 am

FriscoHeavy wrote:
The tires have a higher rated speed limit to allow more weight/payload, which in turn means needing a faster rotation speed. It's not about fuel load, but weight overall.

I don't know if they were installed by BA at the build or put on after market.


What’s the spec on the tire? What’s the tire speed limitation on the Delta 777s in question? Clearly the gross weight carried by the tire and wheel assemblies is a function of overall weight, not just fuel...

A tire speed limitation of 204 Kts sounds close, it’s 195 kts for the New Gen 737s.... I believe the 767-400 has the same tire and wheel assembly as the 777-200s, specifically the CAL a/c...
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Fri Oct 02, 2020 1:55 am

Friscoheavy, 3 models of the 777-200 (UA) have MGTOWs of 545000, 648000 and 656000 lbs. Same 204kt tire speed limit for all 3. What is the MGTOW and tire speed limit for the Delta 777-200LRs? Really interested in the custom tires Delta uses(?)
 
Max Q
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Re: Tire-speed-limit exceedance

Fri Oct 02, 2020 9:26 pm

EssentialPowr wrote:
FriscoHeavy wrote:
The tires have a higher rated speed limit to allow more weight/payload, which in turn means needing a faster rotation speed. It's not about fuel load, but weight overall.

I don't know if they were installed by BA at the build or put on after market.


What’s the spec on the tire? What’s the tire speed limitation on the Delta 777s in question? Clearly the gross weight carried by the tire and wheel assemblies is a function of overall weight, not just fuel...

A tire speed limitation of 204 Kts sounds close, it’s 195 kts for the New Gen 737s.... I believe the 767-400 has the same tire and wheel assembly as the 777-200s, specifically the CAL a/c...



That’s correct, while doing the walk around on the 764 you can see the tires have 777 on them
The best contribution to safety is a competent Pilot.


GGg
 
FriscoHeavy
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Re: Tire-speed-limit exceedance

Fri Oct 02, 2020 10:10 pm

EssentialPowr wrote:
Friscoheavy, 3 models of the 777-200 (UA) have MGTOWs of 545000, 648000 and 656000 lbs. Same 204kt tire speed limit for all 3. What is the MGTOW and tire speed limit for the Delta 777-200LRs? Really interested in the custom tires Delta uses(?)


I don’t know what the tire speed limit is for the Delta 77L, but they certainly have a higher rated speed.
Whatever
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 1:39 am

FriscoHeavy wrote:
EssentialPowr wrote:
Friscoheavy, 3 models of the 777-200 (UA) have MGTOWs of 545000, 648000 and 656000 lbs. Same 204kt tire speed limit for all 3. What is the MGTOW and tire speed limit for the Delta 777-200LRs? Really interested in the custom tires Delta uses(?)


I don’t know what the tire speed limit is for the Delta 77L, but they certainly have a higher rated speed.


Higher than what? If you don’t know the limit, what does “higher rated speed” mean?
 
FriscoHeavy
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 1:52 am

EssentialPowr wrote:
FriscoHeavy wrote:
EssentialPowr wrote:
Friscoheavy, 3 models of the 777-200 (UA) have MGTOWs of 545000, 648000 and 656000 lbs. Same 204kt tire speed limit for all 3. What is the MGTOW and tire speed limit for the Delta 777-200LRs? Really interested in the custom tires Delta uses(?)


I don’t know what the tire speed limit is for the Delta 77L, but they certainly have a higher rated speed.


Higher than what? If you don’t know the limit, what does “higher rated speed” mean?


The tire speed limit on thr Delta 77L is higher/faster than that of 77E’s, 77W’s and even other 77L’s.

There really isn’t much more to explain. As an example only, if the stock max tire speed is 200 mph, the ‘higher rated’ Delta tires allow for something like 210 mph. Again, I’m making up these numbers, but the principle applies.
Whatever
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 2:04 am

FriscoHeavy wrote:
EssentialPowr wrote:
FriscoHeavy wrote:

I don’t know what the tire speed limit is for the Delta 77L, but they certainly have a higher rated speed.


Higher than what? If you don’t know the limit, what does “higher rated speed” mean?


The tire speed limit on thr Delta 77L is higher/faster than that of 77E’s, 77W’s and even other 77L’s.

There really isn’t much more to explain. As an example only, if the stock max tire speed is 200 mph, the ‘higher rated’ Delta tires allow for something like 210 mph. Again, I’m making up these numbers, but the principle applies.


I understand the principle. If you’re making a claim on a technical forum, quoting the actual spec or limitation for what I assume is the -200LR would be appropriate, as that is the entire point. The MGTOW is heavier, but that doesn’t necessarily mean the tire spec nor limitations are different from the other 777 variants. It may be, so that was my specific question. If you don’t know, ok, but I’m not sure what point you were trying to make without some specifics.
 
blacksoviet
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 2:57 am

EssentialPowr wrote:
FriscoHeavy wrote:
EssentialPowr wrote:

Higher than what? If you don’t know the limit, what does “higher rated speed” mean?


The tire speed limit on thr Delta 77L is higher/faster than that of 77E’s, 77W’s and even other 77L’s.

There really isn’t much more to explain. As an example only, if the stock max tire speed is 200 mph, the ‘higher rated’ Delta tires allow for something like 210 mph. Again, I’m making up these numbers, but the principle applies.


I understand the principle. If you’re making a claim on a technical forum, quoting the actual spec or limitation for what I assume is the -200LR would be appropriate, as that is the entire point. The MGTOW is heavier, but that doesn’t necessarily mean the tire spec nor limitations are different from the other 777 variants. It may be, so that was my specific question. If you don’t know, ok, but I’m not sure what point you were trying to make without some specifics.

The reason Delta installed special tires on their 77Ls is because they did not want to make fuel stops when they encountered headwinds on the JNB-ATL flight.

If a regular 77L flew on that route they would likely have to make an unplanned stop if they encountered severe headwinds. These tires eliminate that problem and allow Delta to fly through any weather, no matter how hot it is at JNB. These are very capable aircraft and it will be a shame if they are scrapped. There is another thread suggesting that United Airlines should buy the entire fleet.

Tech stops cost time and time is money. If a 77L is on the ground it is not making money.
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 3:09 am

blacksoviet wrote:
EssentialPowr wrote:
FriscoHeavy wrote:

The tire speed limit on thr Delta 77L is higher/faster than that of 77E’s, 77W’s and even other 77L’s.

There really isn’t much more to explain. As an example only, if the stock max tire speed is 200 mph, the ‘higher rated’ Delta tires allow for something like 210 mph. Again, I’m making up these numbers, but the principle applies.


I understand the principle. If you’re making a claim on a technical forum, quoting the actual spec or limitation for what I assume is the -200LR would be appropriate, as that is the entire point. The MGTOW is heavier, but that doesn’t necessarily mean the tire spec nor limitations are different from the other 777 variants. It may be, so that was my specific question. If you don’t know, ok, but I’m not sure what point you were trying to make without some specifics.

The reason Delta installed special tires on their 77Ls is because they did not want to make fuel stops when they encountered headwinds on the JNB-ATL flight.

If a regular 77L flew on that route they would likely have to make an unplanned stop if they encountered severe headwinds. These tires eliminate that problem and allow Delta to fly through any weather, no matter how hot it is at JNB. These are very capable aircraft and it will be a shame if they are scrapped. There is another thread suggesting that United Airlines should buy the entire fleet.

Tech stops cost time and time is money. If a 77L is on the ground it is not making money.


So what is the spec or limitation on the tires? It’s a readIly apparent criteria to lift the most weight off a given runway on a given day. The specific question remains the same: what is the spec on the tire for the -200LR, as I suspect other airlines would utilize it for the same reason as tires are relatively cheap. If the tire speed limitation on those aircraft is the same as the other fleet types, then that isn’t unique as far as a “special tire”. Maybe that sub fleet has a specific tire, but if not then the “custom tire” issue is just another unsubstantiated claim. If the MGTOW is heavier, the tires are far from the singular reason.

Friscoheavy, “ The tire speed limit on thr Delta 77L is higher/faster than that of 77E’s, 77W’s and even other 77L’s.

There really isn’t much more to explain. As an example only, if the stock max tire speed is 200 mph, the ‘higher rated’ Delta tires allow for something like 210 mph. Again, I’m making up these numbers...”

Then what you are stating is simply a claim, unless you can cite a spec.
 
GSOtoIND
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 5:27 am

EssentialPowr wrote:
blacksoviet wrote:
EssentialPowr wrote:

I understand the principle. If you’re making a claim on a technical forum, quoting the actual spec or limitation for what I assume is the -200LR would be appropriate, as that is the entire point. The MGTOW is heavier, but that doesn’t necessarily mean the tire spec nor limitations are different from the other 777 variants. It may be, so that was my specific question. If you don’t know, ok, but I’m not sure what point you were trying to make without some specifics.

The reason Delta installed special tires on their 77Ls is because they did not want to make fuel stops when they encountered headwinds on the JNB-ATL flight.

If a regular 77L flew on that route they would likely have to make an unplanned stop if they encountered severe headwinds. These tires eliminate that problem and allow Delta to fly through any weather, no matter how hot it is at JNB. These are very capable aircraft and it will be a shame if they are scrapped. There is another thread suggesting that United Airlines should buy the entire fleet.

Tech stops cost time and time is money. If a 77L is on the ground it is not making money.


So what is the spec or limitation on the tires? It’s a readIly apparent criteria to lift the most weight off a given runway on a given day. The specific question remains the same: what is the spec on the tire for the -200LR, as I suspect other airlines would utilize it for the same reason as tires are relatively cheap. If the tire speed limitation on those aircraft is the same as the other fleet types, then that isn’t unique as far as a “special tire”. Maybe that sub fleet has a specific tire, but if not then the “custom tire” issue is just another unsubstantiated claim. If the MGTOW is heavier, the tires are far from the singular reason.

Friscoheavy, “ The tire speed limit on thr Delta 77L is higher/faster than that of 77E’s, 77W’s and even other 77L’s.

There really isn’t much more to explain. As an example only, if the stock max tire speed is 200 mph, the ‘higher rated’ Delta tires allow for something like 210 mph. Again, I’m making up these numbers...”

Then what you are stating is simply a claim, unless you can cite a spec.

I found a press release from Bridgestone about their being chosen as the tire supplier for the 77L/W that lists the maximum rated speed as 235 MPH. The takeoff runway length charts in Boeing's ACAP also list the tire speed limit as 235. I can't find where I read this, but the "special" tire DL uses was supplied by Goodyear. The speed rating for this tire is a known quantity, but it doesn't seem to be easily accessible.
Bridgestone page: https://www.bridgestone.com/products/sp ... 20_01.html
Boeing 777L/W/F ACAP: http://www.boeing.com/resources/boeingd ... 2lr3er.pdf
 
EssentialPowr
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Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 6:39 am

GSOtoIND wrote:
I found a press release from Bridgestone about their being chosen as the tire supplier for the 77L/W that lists the maximum rated speed as 235 MPH. The takeoff runway length charts in Boeing's ACAP also list the tire speed limit as 235. I can't find where I read this, but the "special" tire DL uses was supplied by Goodyear. The speed rating for this tire is a known quantity, but it doesn't seem to be easily accessible.
Bridgestone page: https://www.bridgestone.com/products/sp ... 20_01.html
Boeing 777L/W/F ACAP: http://www.boeing.com/resources/boeingd ... 2lr3er.pdf


Excellent work. I looked up the Goodyear tires spec’d for the 737-900ER mains per this page: https://www.goodyearaviation.com/resour ... 6-2018.pdf. It shows a speed rating of 235 kts, but the limitation in the FM is 195 kts (obviously a safety margin). It shows a different tire between the 777-200 and the -200LR, but both have the same speed rating of 235 knots. Michelin shows the same 2 main tire sizes for the -200 vs -LR but doesn’t show speed ratings; my guess is they are 235 kts as well.

I assume Delta operates all the 777s with the same tire speed limitation for commonality; that was what I was trying to confirm (204 kts?)

As far as FRISCOHeavy’s claim that Delta has a “custom” tire for their -200LRs, that can be shown as completely false as both Bridgestone and Goodyear, and probably Michelin, each offer a tire for all models of the 777 with a 235 kt manufacturer’s speed rating. Just about any performance enhancement is typically NOT exclusive to a particular airline customer, as that would cut profit potential of that enhancement. Thanks to GSOtoIND for the info...
 
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zeke
Posts: 15939
Joined: Thu Dec 14, 2006 1:42 pm

Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 3:03 pm

EssentialPowr wrote:
Excellent work. I looked up the Goodyear tires spec’d for the 737-900ER mains per this page: https://www.goodyearaviation.com/resour ... 6-2018.pdf. It shows a speed rating of 235 kts, but the limitation in the FM is 195 kts (obviously a safety margin). It shows a different tire between the 777-200 and the -200LR, but both have the same speed rating of 235 knots. Michelin shows the same 2 main tire sizes for the -200 vs -LR but doesn’t show speed ratings; my guess is they are 235 kts as well.


The column is clearly labeled "SPEED (MPH)", the 777 is limited like most widebodies to 204 kts (235 mph), if you want to exceed that speed then you need to vary the certification basis by way of STC, I have not been able to locate an STC on the FAA database which applies to any 777 wheels/tyre https://rgl.faa.gov/Regulatory_and_Guid ... enFrameSet

I m thinking this is yet another a.net myth busted, someone might have done exactly as you have done and taken the speed in mph and stated it is knots which is not the same type of mile.
“Don't be a show-off. Never be too proud to turn back. There are old pilots and bold pilots, but no old, bold pilots.” E. Hamilton Lee, 1949
 
EssentialPowr
Posts: 1732
Joined: Wed Sep 06, 2000 10:30 pm

Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 5:22 pm

zeke wrote:
EssentialPowr wrote:
Excellent work. I looked up the Goodyear tires spec’d for the 737-900ER mains per this page: https://www.goodyearaviation.com/resour ... 6-2018.pdf. It shows a speed rating of 235 kts, but the limitation in the FM is 195 kts (obviously a safety margin). It shows a different tire between the 777-200 and the -200LR, but both have the same speed rating of 235 knots. Michelin shows the same 2 main tire sizes for the -200 vs -LR but doesn’t show speed ratings; my guess is they are 235 kts as well.


The column is clearly labeled "SPEED (MPH)", the 777 is limited like most widebodies to 204 kts (235 mph), if you want to exceed that speed then you need to vary the certification basis by way of STC, I have not been able to locate an STC on the FAA database which applies to any 777 wheels/tyre https://rgl.faa.gov/Regulatory_and_Guid ... enFrameSet

I m thinking this is yet another a.net myth busted, someone might have done exactly as you have done and taken the speed in mph and stated it is knots which is not the same type of mile.


The issue was whether it was a “special custom tire” that Delta possibly had sole use of per Friscoheavy’s comment. In order to resolve that claim, a spec would have been necessitated. I have offered all along that the 204kt tire speed limitation per one airline’s FM is probably consistent among US airlines for the 777, so the busted myth is Delta’s “custom” tire. It is interesting that tire manufacturers provide limits in mph vs knots.

I would also add when Northwest STC’d some of their 727-200s to increase the landing weights, and I believe MGTOWs for example, it was purely a paperwork drill with nothing changing mechanically. There is usually significant margin in any contemporary design...
 
FriscoHeavy
Posts: 1831
Joined: Tue May 27, 2014 4:31 pm

Re: Tire-speed-limit exceedance

Sat Oct 03, 2020 7:50 pm

zeke wrote:
EssentialPowr wrote:
Excellent work. I looked up the Goodyear tires spec’d for the 737-900ER mains per this page: https://www.goodyearaviation.com/resour ... 6-2018.pdf. It shows a speed rating of 235 kts, but the limitation in the FM is 195 kts (obviously a safety margin). It shows a different tire between the 777-200 and the -200LR, but both have the same speed rating of 235 knots. Michelin shows the same 2 main tire sizes for the -200 vs -LR but doesn’t show speed ratings; my guess is they are 235 kts as well.


The column is clearly labeled "SPEED (MPH)", the 777 is limited like most widebodies to 204 kts (235 mph), if you want to exceed that speed then you need to vary the certification basis by way of STC, I have not been able to locate an STC on the FAA database which applies to any 777 wheels/tyre https://rgl.faa.gov/Regulatory_and_Guid ... enFrameSet

I m thinking this is yet another a.net myth busted, someone might have done exactly as you have done and taken the speed in mph and stated it is knots which is not the same type of mile.



If that’s the case, then I stand corrected. No big deal. I know it’s been discussed on here before, but you bring up a very plausible explanation. Thank you for that.
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