ferpe
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787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 10:07 am

In a general AW article about all new Boeing DA aircraft programs (and the 747-8 in the headline) is hidden SOME REAL NEWS  Wow! (and it sound like they know what they are talking about), here goes:

"The -10X involves more than adding fuselage plugs to the 787-9. There are indications that a redesign of the infamous side-of-body join, where composite delamination issues caused delay for the 787-8, will be needed to accommodate the stretched aircraft's greater loads. A redesign also offers the promise of improved performance in the wing. An upgraded environmental control system is likely, as is a stronger main landing gear that uses six-wheel trucks, as does the 777-300ER. "

That sounds very much like the start of the 787-10HGW, a cleaned up and stronger wing - center wingbox join can carry a higher MTOW then the 789 as can a 6 wheel MLG. With these modifications the route up to some 280t should be prepared and ranges that make the 787-10 a real long-haul frame (280t gives you some 8000nm with the present wing). Don't be surprised to see the final offered variant pass 7000nm with full passenger load with a margin and then gradually stepping up to 8000nm as times goes. The engines are probably the limiting factor more then the wing so as these can add power so will the 787-10 add MTOW and thus range.

The new MLG would possibly restrict the cargo to 40 LD3 with the present 9 frame stretch, a small sacrifice and a good move. If you go to the trouble of certifying a new variant better remove some of the bottle-necks that you can in the process and those that you can't (the engines) you follow their stepwise development.

So we get a real A359 competitor after all in the 787 range, mile by mile or really lbf by lbf  .

[Edited 2012-12-03 02:13:32]
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sweair
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 10:11 am

What market does that leave for the 777-8X?
 
BlueSky1976
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 10:52 am

None, unfortunately...

Sniff... sniff...
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RickNRoll
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 11:10 am

So if the cost of development of the 777X can't be spread across the 778-8X as well, does that mean reducing the scope of the 9X as well? Expanding the scope and cost of development of 787-10 logically means reducing that of the 9X. Just as the A330 is competitive for years yet, so the 777 might be with not so much development more than a pretty simple stretch.
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 11:15 am

Interesting! Surely expecting a MTOW increase now
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SeJoWa
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 11:18 am

Interesting catch, ferpe!

Quoting RickNRoll (Reply 3):
Expanding the scope and cost of development of 787-10 logically means reducing that of the 9X.

Not necessarily. If the putative 777-8 goes to the boneyard in the sky, then the -9 could be better optimized for its missions and hence more competitive. 777-9 and -10 anyone?
 
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JerseyFlyer
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 11:32 am

So the 7810 moves from an A333 killer to an A359 direct competitor.

Does that mean the A333 lives longer?
 
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zeke
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 11:49 am

Quoting ferpe (Thread starter):


Sounds like they are using a similar approach as what Airbus did from the -900 to -1000. The additional wheels, increased wing loads, and changes to the ECS may also mean the possibility of another fuselage extension.
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RickNRoll
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 11:55 am

Quoting SeJoWa (Reply 5):
Not necessarily. If the putative 777-8 goes to the boneyard in the sky, then the -9 could be better optimized for its missions and hence more competitive. 777-9 and -10 anyone?

Wouldn't a -10 be too long to be practicable.
 
rheinwaldner
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 12:17 pm

Do you see what I meant in all these 77X threads about a 787-based A351 competitor?

A new landing gear is a more extensive upgrade that I would have thought to be required to approach A351 capability from below. If Boeing brings forward the 787 that much, a 340 seat, high performance version won't be out of reach anymore.

With such a 781X Boeing won't need the 77X to compete against the A351.

Bye bye 77X.
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 12:50 pm

Quoting ferpe (Thread starter):

I wonder what sort of a weight and fuel burn penalty this will cause on the 787-10. The 787-10 as it was would have been a terrific A333 replacement on medium haul (10 hour) routes. I think the addition of the triple bogie main landing gear will have a negative effect its trip fuel burn for such routes.

Also, are there any plans to increase the wingspan on the 787-10? At just 60m it seems to be on the small side for an airliner with its size and mission profile, particularly if Boeing wishes to increase the range of the 787-10.

Quoting RickNRoll (Reply 3):
Expanding the scope and cost of development of 787-10 logically means reducing that of the 9X.

No.

While I agree that the base 777-8X is all but dead (though the ultra long range 777-8LX and a "777-8F" is still a possibility), the 787-10 isn't anywhere near big enough to take on the market of the 777-300ER and its successor, the 777-9X. What the advent of the 787-10 means is that the 777X family will be reduced. It will not make the 777X family redundant.

I think it is a good strategy for Boeing to sandwich the A350-1000 between two of its models, the 787-10 and the 777-9X. Without a competitive and heavily revised 777-9X, Boeing wouldn't have much of a competitive offering if airlines wanted something between the size of the A350-1000 and the A380.

Quoting rheinwaldner (Reply 9):
With such a 781X Boeing won't need the 77X to compete against the A351.

Bye bye 77X.

In your dreams.  
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:00 pm

Quoting ferpe (Thread starter):
There are indications that a redesign of the infamous side-of-body join, where composite delamination issues caused delay for the 787-8, will be needed to accommodate the stretched aircraft's greater loads.

Going back into history when the SOB issues and weight creep became evident back in 2009/10 the smart money was on a complete SOB redesign and 6 wheel boggies (you can check the archieve) but there were some who insisted that Boeing could cheat physics, not so.

Also at this point I'm thinking ironic thoughts about the recent thread that insisted that the A350-1000 was a dead end with no room for growth without a major redesign (not true), seems that the B789 has this problem in spades.
BV
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:04 pm

Quoting ferpe (Thread starter):
That sounds very much like the start of the 787-10HGW, a cleaned up and stronger wing - center wingbox join can carry a higher MTOW then the 789 as can a 6 wheel MLG.

Wouldn't make these added modifications the -10X a lot heavier, thus compromising its biggest advantage towards the A359? Please correct me if I'm wrong, but I've heard a 6 wheel bogie implies some stiff weight penalties.

Quoting ferpe (Thread starter):
The engines are probably the limiting factor more then the wing so as these can add power so will the 787-10 add MTOW and thus range.

Perhaps we'll see a modified GE9x appear on the -10X to compete with RR's Trent-1000 TEN, GE is working hard on it anyway for an and of the decade EIS.

Quoting rheinwaldner (Reply 9):
With such a 781X Boeing won't need the 77X to compete against the A351.

It would need another stretch, and I'm not so sure Boeing will go that far.

And I don't write the 777-9X off just yet, although it becomes more and more likely Boeing will eventually have a 787-10 with GE9x and RB3025 engines and 8000+ NM range. Possibly developing an all new widebody family offering 77W/747 replacements, GTF engines, EIS 2023/2024, right at the start of the 77W replacement cycle.
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:13 pm

Quoting frigatebird (Reply 12):
Perhaps we'll see a modified GE9x appear on the -10X to compete with RR's Trent-1000 TEN, GE is working hard on it anyway for an and of the decade EIS.

We have the bleed v non bleed problem here again, a GE9x would have to be completely re engineered for the 787. But I think that the GEnx is at the top of its thrust range for the 789 anyway, this is another problem with a double stretch.

[Edited 2012-12-03 05:14:58]
BV
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:15 pm

Quoting RickNRoll (Reply 8):
Quoting SeJoWa (Reply 5):
Not necessarily. If the putative 777-8 goes to the boneyard in the sky, then the -9 could be better optimized for its missions and hence more competitive. 777-9 and -10 anyone?

Wouldn't a -10 be too long to be practicable.

I can't say. But there's a market for a twin widebody with the highest capacity that's practical to build, and it would be a lucrative niche for sure. On the other hand, Boeing is still making hopeful noises regarding the 747-8I... ( and we know how many of those Emirates have bought, even though they say that growth will be mainly via airplane size upgrades ).
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:23 pm

Quoting BoeingVista (Reply 13):
Quoting frigatebird (Reply 12):Perhaps we'll see a modified GE9x appear on the -10X to compete with RR's Trent-1000 TEN, GE is working hard on it anyway for an and of the decade EIS.
We have the bleed v non bleed problem here again, a GE9x would have to be completely re engineered for the 787

At this stage of the development, I don't think it would cause GE that many headaches (although I admit it wouldn't be something trivial either) GE initially started both bleed and non bleed (for the non-XWB A350) versions of the GENx too...
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:36 pm

Quoting CXB77L (Reply 10):
In your dreams.

My dreams are not related in any way to the 77X.

Quoting CXB77L (Reply 10):
It will not make the 777X family redundant.

I agree fully. With the 77X Boeing will try to conquer markets that have been adressed before (748) but that are in danger to be covered by future 787 upgrades.

Quoting frigatebird (Reply 12):
Quoting rheinwaldner (Reply 9):
With such a 781X Boeing won't need the 77X to compete against the A351.

It would need another stretch, and I'm not so sure Boeing will go that far.

The new landing gear would not be needed for A359 capability. Proof: the A359.

So what else does Boeing have in mind?

I would say any stretch is easy-peasy compared to the wing/center-wing-box changes that go with 6 wheel MLG. The newsworthy part in this thread is the High-MTOW version of the 787, that will be on the radar from now on. The length of that plane will only be a minor variable, that can be adjusted to match the sweetest portion of the market. Anything up to 340-350 should be straight forward...
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:49 pm

The original range of the 787-10X is about 6750 nm, reportedly potential customers want a range over 7000 nm, but I never see 8000 nm range for this aircraft, this range is reserved for the 787-9 and 777X (all variants) respectively. The six wheel MLG is not a surprise, given to the heavy stretch over the basic 787 frame.

I don't see why Boeing should kill the 777-8X variant. Do not forget that Boeing eventually needs a platform for a later 777X freighter, so a 777-9X shrink is a must-have.
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:53 pm

Quoting ferpe (Thread starter):
"The -10X involves more than adding fuselage plugs to the 787-9. There are indications that a redesign of the infamous side-of-body join, where composite delamination issues caused delay for the 787-8, will be needed to accommodate the stretched aircraft's greater loads. A redesign also offers the promise of improved performance in the wing. An upgraded environmental control system is likely, as is a stronger main landing gear that uses six-wheel trucks, as does the 777-300ER. "

Very interesting news. Thanks for posting.

Quoting zeke (Reply 7):
Sounds like they are using a similar approach as what Airbus did from the -900 to -1000. The additional wheels, increased wing loads, and changes to the ECS may also mean the possibility of another fuselage extension.

It sure looks that way.  .

Quoting JerseyFlyer (Reply 6):
So the 7810 moves from an A333 killer to an A359 direct competitor.

It sure looks that way too!  .

Quoting rheinwaldner (Reply 9):

Do you see what I meant in all these 77X threads about a 787-based A351 competitor?

You have said it all along, I commend you for that. But they are not at A351-capacities yet.

Quoting rheinwaldner (Reply 9):
With such a 781X Boeing won't need the 77X to compete against the A351.

They will not need the B777-8X for sure now.

Quoting CXB77L (Reply 10):
In your dreams.

Maybe, maybe not. But these changes to the B787-10X are influencing the business case for the B777-X-program. For sure the B778-X is now an even more highly doubtful proposal imho.

Quoting frigatebird (Reply 12):
It would need another stretch, and I'm not so sure Boeing will go that far.

But the potential is now there.

Quoting BoeingVista (Reply 13):
But I think that the GEnx is at the top of its thrust range for the 789 anyway, this is another problem with a double stretch.

True, but the potential is there. At least from RR.  .

Quoting rheinwaldner (Reply 16):
The new landing gear would not be needed for A359 capability. Proof: the A359.

So what else does Boeing have in mind?

That question will be answered as the program comes along. When that will be only Boeing can tell us.  . Interesting times ahead, as always. But Boeing seems to be following more and more the concepts Airbus is bringing to the market. We have seen it with the B737-MAX and now they seem to be "copying" the A350 program structures.

[Edited 2012-12-03 05:54:09]
 
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zeke
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 1:58 pm

Quoting rheinwaldner (Reply 16):

The new landing gear would not be needed for A359 capability. Proof: the A359.

So what else does Boeing have in mind?

My guess it is a tyre pressure issue, they are probably pushing 240-250 psi.
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morrisond
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:03 pm

As others have suggested above, and I have pointed many a time - The 787 barrel has a lot of future capability in it. A 280T 787 effectively kills the 77W. The Barrels are very similarly sized - only a 9" difference in Height is inmaterial although the barrel is maxed out at 9W - you don't get the same comfort in a 777 barrel at 10W. As for engines the 789 is launching with 71,000 LB engines - the engine OEM's are already pushing there designs to 76-78,000 - with wing tweaks wouldn't this be in the right thrust class?

I can see a 77W+ as mentioned in articles from last week with a 4-5% Fuel burn improvement in the 2016-2017 timeframe to get to a complete replacement in the early 2020's with the program starting very soon, with the improvements carrying over to the 77F program.

A 2020's technology - all carbon 12W Eliptical (same cross section area as the 777) 70M (375-400 seats - huge range) and 80M Twin (450 + seats - 8,000NM range) with up to 80M wings would put some serious hurt on the A380 program - kill the 787i and take Boeing into New size ranges. This plane should be possible with engines in existing thrust ranges.

Mastering non-standard Fuselage cross sections (possibly using non-autoclave carbon) makes sense at the relatively low volumes of a Y3 sized aircraft.
 
BlueSky1976
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:08 pm

Quoting Ronaldo747 (Reply 17):
Do not forget that Boeing eventually needs a platform for a later 777X freighter, so a 777-9X shrink is a must-have.

The thing is, 777-8X was not being conceived as the shrink of -9X, contrary to the belief on this forum. It was going to be a stretch of the current 777-200ER with a lighter wing. At least that's what the original idea of it was.

I'm still hoping Boeing decides to build it, however, with this latest development I'm afraid the 787-10X will turn out to become the "777-200ER/-8X killer".

Well... at least 777-9X is a sure thing.
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:10 pm

Quoting rheinwaldner (Reply 16):
With the 77X Boeing will try to conquer markets that have been adressed before (748) but that are in danger to be covered by future 787 upgrades.

  

I do not believe any 787 variant will ever supplant the 777-300ER, let alone the 777-9X. It was simply never designed to be stretched that far in the first place. The 787-10 is as big as the 787 will get, although higher MTOW variants remain a possibility.

The 787-10 may have the range (with an MTOW upgrade - which is by no means definite), it may have the fuel burn, but it does not have the cargo carrying capacity or the seating capacity of the 777-300ER. The 777-9X will only raise the bar further in that respect.

The 777 and 787 families of aircraft are distinct and separate. The increase in the 787's capabilities - which is terrific for the 787 family, by the way - does not mean

Quoting rheinwaldner (Reply 9):
Bye bye 77X.

... not by a long shot.

Quoting rheinwaldner (Reply 16):
I would say any stretch is easy-peasy compared to the wing/center-wing-box changes that go with 6 wheel MLG.

  

Quoting SEPilot (Reply 26):
the stiffness to strength ratio for CFRP is lower than for aluminum, which means with the same strength you will get more deflection with CFRP as opposed to aluminum (hence the much greater wing flex with CFRP wings). Fuselage flex with an airliner is much more important than wing flex, and hence with the CFRP fuselage (especially with the smaller diameter) and a very long fuselage you may have to add structure to get the necessary stiffness beyond what is required for structural strength. Hence you may lose the weight savings of CFRP. Overall, you are probably better off with the larger diameter Al fuselage rather than trying to extend a smaller diameter CFRP fuselage to get the same capacity. There comes a point (as the A346 proved) where a extending a given fuselage diameter is a case of diminishing returns, and that will be true no matter what the material
777X Vs 787-11/12 (by morrisond Sep 20 2011 in Civil Aviation)

Quoting Ronaldo747 (Reply 17):
I don't see why Boeing should kill the 777-8X variant. Do not forget that Boeing eventually needs a platform for a later 777X freighter, so a 777-9X shrink is a must-have.

  

The base 777-8X variant probably won't get off the ground, but there's still the ultra long haul 777-8LX and a potential 777-8F variant to be built. There's little doubt in my mind that although the 777-9X will dominate the 777X family sales going foward, its smaller sibling will also be developed, if only as a freighter/ultra long hauler.

[Edited 2012-12-03 06:15:16]
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rheinwaldner
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:27 pm

Quoting CXB77L (Reply 22):
Quoting rheinwaldner (Reply 16):
With the 77X Boeing will try to conquer markets that have been adressed before (748) but that are in danger to be covered by future 787 upgrades.

Sorry, you are right of course. I wanted to say "not in danger" to be covered by future 787 upgrades...
 
strfyr51
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:30 pm

Quoting BoeingVista (Reply 13):

with the GE90-115 the most powerful GE engine? Then Gen 1b engine could easily exceed that 115K thrust limit
The answer is?? will there BE enough room for the FAN to make that Thrust?? ??
The Triple Bogey Landing gear we at United call "BIGFOOT" will solve the problem because it is large and LONG enough to support a 115 in fan already this will obviously change the Ground stance with the smaller 787's but not significantly enough to make It undoable
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:45 pm

Quoting strfyr51 (Reply 24):
Then Gen 1b engine could easily exceed that 115K thrust limit

No it couldn't core is too small.

Its like saying that Dodge make NASCAR engines so a Cirus engine can be made good to race in NASCAR.
BV
 
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zeke
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 2:49 pm

Quoting strfyr51 (Reply 24):
with the GE90-115 the most powerful GE engine? Then Gen 1b engine could easily exceed that 115K thrust limit
The answer is?? will there BE enough room for the FAN to make that Thrust?? ??

With todays technology they do not need an engine the size of the GE90-115 to power an aircraft the size of the 77W.
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 3:14 pm

Quoting CXB77L (Reply 10):
I think the addition of the triple bogie main landing gear will have a negative effect its trip fuel burn for such routes.

Agree. You can see this in the effect that it has on the A350-1000 relative to the A350-900.
however, it does raise some very interesting questions about how far Boeing may push the 787-10 in the future.
As Rheinwaldner pointed out, the A350-900 is approaching 270t MTOW on a double bogie MLG

Quoting CXB77L (Reply 10):
At just 60m it seems to be on the small side for an airliner with its size and mission profile

If the weights go beyond 250t in any meaningful way, I'd tend to agree

Quoting BoeingVista (Reply 11):
Also at this point I'm thinking ironic thoughts about the recent thread that insisted that the A350-1000 was a dead end with no room for growth without a major redesign (not true), seems that the B789 has this problem in spades

One or two of us went to some lengths to point out the inconsistency of some of the thinking on that thread.
Wasn't all that well received in some quarters though. It seemed much more fashionable to single out the A350-1000 for some unique treatment..

Quoting strfyr51 (Reply 24):
Then Gen 1b engine could easily exceed that 115K thrust limit
The answer is?? will there BE enough room for the FAN to make that Thrust?? ??

???
The GEnx 1B will never get anywhere near that.   
A brand new engine based on its technology could, of course

Rgds
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 3:16 pm

Quoting Ronaldo747 (Reply 17):
The six wheel MLG is not a surprise, given to the heavy stretch over the basic 787 frame.

Everyone has been assuming the 787-10 would have the same MTOW (~251t) of the 787-9, so there was no need for a revised main gear geometry.

The only reason Boeing needs a six-wheel bogey on the 787-10 is because they're going for significantly heavier weights - 20-30t, IMO.

GE and RR have both been working on more powerful engines for the 787-9 and 787-10. My guess was it was meant to improve field performance, but they would also be necessary to support higher take-off weights.

As for the wingspan, I think it safe to assume we'll see 63-65m because the extra weight is no longer a real penalty since you have so much TOW growth.

I also could see Boeing going with a 6m stretch as opposed to 5m. That would give the 787-10 the same 3m fuselage cabin length advantage over the A350-900 that the A350-900 has over the 787-9. So you'd be able to seat an additional 27 passengers over an A350-900 (and 52 over a 787-9). This would also provide room for 44 LD3 positions - an 8 LD3 position advantage over the A350-900 and 787-9.

The A350-900 should still have the range advantage - at MZFW it can tank 76t of fuel whereas I could see the 787-10 at around 70t (210t MZFW | 280t MTOW).
 
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zeke
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 3:38 pm

Quoting Stitch (Reply 28):

The only reason Boeing needs a six-wheel bogey on the 787-10 is because they're going for significantly heavier weights - 20-30t, IMO.

Bit of an overkill for 280t, that woud be around 20 t per wheel, 5 wheel would be around 25, and 8 around 30. The norm would be 25-30t per wheel.
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bigjku
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 3:40 pm

For a moment I thought Boeing should consider doing both versions of the 10, the stretch only and the increased MTOW, but I get why they wouldn't. They can leverage a huge portion that would have bought the stretch only into helping pay to develop the higher MTOW variant of the airplane which may or may not be the basis for other frames in the future.

As for the 777x I am curious what this does to it. If you could stretch the 787 to an 11 model and complete with the A351 directly then things get interesting. Does Boeing either remake 777x or move down the road to a Y3 approach or some blend. Were I Boeing I would be looking to use by 777x/Y3 to offer a true 10 across, ultra low CASM airliner that would make life tough for the A350/787 and would be able to serve as the top end large airliner for most airliners not named Emirates.
 
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 3:45 pm

Quoting zeke (Reply 19):
My guess it is a tyre pressure issue, they are probably pushing 240-250 psi.

This is very likely. The 787-8 already has really really high tire loading, it's only going to get worse on the stretches.
 
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Stitch
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 3:58 pm

Quoting zeke (Reply 29):
Bit of an overkill for 280t, that woud be around 20 t per wheel, 5 wheel would be around 25, and 8 around 30. The norm would be 25-30t per wheel.


A 69m long, 65m span, 300t 787-10 would offer more passenger seating, more cargo volume and longer range than the A350-900, so it would be a compelling option for many carriers (EK alone could be hundreds of frames).

And if Boeing is going to 300t, then a 75m 787-11 designed o compete with the A350-1000 becomes a possibility, IMO. Such a plane would offer about an 18-seat advantage over the A350-1000 and would offer the same cabin length as the 777-9X

[Edited 2012-12-03 07:59:27]
 
JoeCanuck
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:05 pm

I don't think this rules out a simple stretch version of the -10. Not everybody needs the extra capabilities of a HGW and there is no reason why they can't do a -10 lite and a heavy.
What the...?
 
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seabosdca
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:11 pm

Quoting Stitch (Reply 28):
I also could see Boeing going with a 6m stretch as opposed to 5m. That would give the 787-10 the same 3m fuselage cabin length advantage over the A350-900 that the A350-900 has over the 787-9. So you'd be able to seat an additional 27 passengers over an A350-900 (and 52 over a 787-9). This would also provide room for 44 LD3 positions - an 8 LD3 position advantage over the A350-900 and 787-9.

Wouldn't the new landing gear eat at least two of those LD3 positions? So a 6 m stretch might (or might not) be enough to preserve the expected 42 LD3 capacity of the 5 m "simple stretch," but won't likely give 44 LD3 capacity.
 
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Stitch
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:27 pm

Quoting seabosdca (Reply 34):
Wouldn't the new landing gear eat at least two of those LD3 positions?

I would expect it depends on how much larger Section 45 needs to be to accommodate the larger bogies. Airbus had to extend the gear-bay of the A350-1000 by one frame.
 
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BoeingVista
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:35 pm

Quoting Stitch (Reply 32):
A 69m long, 65m span, 300t 787-10 would offer more passenger seating, more cargo volume and longer range than the A350-900, so it would be a compelling option for many carriers (EK alone could be hundreds of frames).

Okay, but surely this is yet another proposed 787-10 version, this is not the one that was rumoured to be offered last month, that one was aimed at the A330-300 this one is targeted at the A350-900.
BV
 
strfyr51
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:41 pm

Quoting Ronaldo747 (Reply 17):

Boeing could build a freighter out of whatever model they field as a passenger model. As a matter of fact the Bigger the Fuselage the Better and more cost effective. there are no major freight ports that already cannot be reached by air and having a 9000KM range isn't going to help when you take off and land at max gross ZFW Every Flight
 
ytz
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:46 pm

Quoting Ronaldo747 (Reply 17):
Do not forget that Boeing eventually needs a platform for a later 777X freighter

Could the 787-10 not serve as a decent freighter?
 
morrisond
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:46 pm

Quoting Stitch (Reply 35):
I would expect it depends on how much larger Section 45 needs to be to accommodate the larger bogies. Airbus had to extend the gear-bay of the A350-1000 by one frame.

As they are redoing the side of Body join - maybe the 781 has a unique section 45 with the Chord of the 781 Wing Wider at the Join (1M?) - essentially putting 2.5M plugs in the existing 788/9 wing and allowing room for a larger MGB?

Maybe the longer Section 45 (call it 1M longer) makes it a 70 M plane with Stitch's 6M Stretch - giving it room for two more rows and giving it a 350 seat (A351) capacity?
 
astuteman
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:46 pm

Quoting Stitch (Reply 28):
Everyone has been assuming the 787-10 would have the same MTOW (~251t) of the 787-9, so there was no need for a revised main gear geometry

Probably because all along that is what Boeing appear to have maintained it was likely to be.

Quoting Stitch (Reply 28):
The only reason Boeing needs a six-wheel bogey on the 787-10 is because they're going for significantly heavier weights - 20-30t, IMO.

GE and RR have both been working on more powerful engines for the 787-9 and 787-10.

Ge and RR have indeed both been working on more powerful engines, but it has always been stated that the push from 75k lb to the (say) 78k lb of the Trent 1000 TEN was to accommodate the requirements of the 787-10 at the existing weight.

I can't see any way a 787-10 at 270 tonnes, (even with a 65m wingspan) will need less thrust than a 270 tonne A350-900 - i.e. 83 000lb.
A 280 tonne MTOW is more likely to need about 87 000lb thrust

To me, that's a different engine altogether to the GEnx 1B and Trent 1000
(Ironically enough, it would look more like the Trent XWB to my eyes...   )

Rgds
 
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Stitch
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 4:46 pm

Quoting BoeingVista (Reply 36):
Okay, but surely this is yet another proposed 787-10 version, this is not the one that was rumoured to be offered last month, that one was aimed at the A330-300 this one is targeted at the A350-900.

Yes it would be a different and more capable airframe than the simple stretch.


Quoting astuteman (Reply 40):
Ge and RR have indeed both been working on more powerful engines, but it has always been stated that the push from 75k lb to the (say) 78k lb of the Trent 1000 TEN was to accommodate the requirements of the 787-10 at the existing weight.

But a 787-10 at the same MTOW of the 787-9 would be able to use the 787-9's engines. Hence my guess it was to improve field performance at the 251t TOW.



Quoting astuteman (Reply 40):
To me, that's a different engine altogether to the GEnx 1B and Trent 1000. (Ironically enough, it would look more like the Trent XWB to my eyes...   

And the GE-9X.

[Edited 2012-12-03 08:55:34]
 
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zeke
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 5:12 pm

Quoting Stitch (Reply 32):
A 69m long, 65m span, 300t 787-10 would offer more passenger seating, more cargo volume and longer range than the A350-900, so it would be a compelling option for many carriers (EK alone could be hundreds of frames).

I have seen these throw away lines far too many times before, what iteration is this of the 787-10 ?

Point being EK, nor any other carrier has placed orders partially due to the design uncertainty, partially due to availability, and thirdly, due to the 777/777X/A350 crossover. Wing design changes, gear changes, engine changes, ECS changes are not free, that is best part of 5 billion in R&D, it is just as complex as going from the A340-300 to A340-600.

The 787 does have a physical limit on growth, and Boeing does have limits on its resources.

Quoting tdscanuck (Reply 31):
This is very likely. The 787-8 already has really really high tire loading, it's only going to get worse on the stretches.

My understanding is the -9 is lower pressure than the -8, different tyre ?
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
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Stitch
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 5:16 pm

Quoting zeke (Reply 42):
I have seen these throw away lines far too many times before, what iteration is this of the 787-10?

The iteration based on what ferpe says AviationWeek believes Boeing may be working on.

The 787-10 is currently projected to be a 5m to 5.5m stretch, so 6m is hardly pushing the envelope. And you were the one who noted that a six-wheel bogie is unnecessary unless you're looking at 300t or more TOW.

We know the 787 at 251t suffers from poor field performance with a 60m span, so such a span seems untenable for a 300t model. On the flip side, the Airbus Aficionados all mention how wonderful a 65m span is for the A350. Since the 63m span was going to weigh 1.8t more than the 60m span, a 65m span should come in at or below 5 tons (to account for additional strengthening). But with TOW going up close to 10x that, it should be acceptable.

And a 300t 787-10 with a 65m span should need around 95,000 pounds of thrust if we use the A350-1000 as a baseline. While well beyond what the GEnx and Trent 1000 can offer, it is not beyond what the GE-9X and Trent XWB can offer. So both companies do have a foundation to build on to scale the GEnx and Trent 1000 (just as both did to develop the high-output GE90-11xB and Trent 8100 series).


Quoting zeke (Reply 42):
My understanding is the -9 is lower pressure than the -8, different tyre?

I recall someone noting that the 787-9's tires are larger diameter than those on the 787-8.

[Edited 2012-12-03 09:32:04]
 
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BoeingVista
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 5:18 pm

Quoting Stitch (Reply 41):

But a 787-10 at the same MTOW of the 787-9 would be able to use the 787-9's engines. Hence my guess it was to improve field performance at the 251t TOW.

If you are keeping the weight the same you do not need a 6 wheel main gear hence the weights are rising and so must thrust.

Quoting Stitch (Reply 41):
Yes it would be a different and more capable airframe than the simple stretch.

Yes another month another 787-10 proposal, I hope all of these designs are electronic or there wont be a single tree left in Washington State

Quoting astuteman (Reply 40):
I can't see any way a 787-10 at 270 tonnes, (even with a 65m wingspan) will need less thrust than a 270 tonne A350-900 - i.e. 83 000lb.
A 280 tonne MTOW is more likely to need about 87 000lb thrust

To me, that's a different engine altogether to the GEnx 1B and Trent 1000

Nope its going to need a thrust bump into the range that neither the Trent 1000 or GEnx-1b are comfortable with, lets hope that neither RR or GE are goaded into making unrealistic promises like last time..

Quoting astuteman (Reply 40):
(Ironically enough, it would look more like the Trent XWB to my eyes... )

And we are back to the non bleed problem yet again! Some really short sighted (or long sighted) decisions were made when designing the 787, its like it was designed by Apple marketing men...
BV
 
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Stitch
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 5:26 pm

Quoting BoeingVista (Reply 44):
If you are keeping the weight the same you do not need a 6 wheel main gear hence the weights are rising and so must thrust.

Exactly what I mentioned in my first response (#28).



Quoting BoeingVista (Reply 44):
And we are back to the non bleed problem yet again! Some really short sighted (or long sighted) decisions were made when designing the 787, its like it was designed by Apple marketing men...

When Boeing launched the 7E7, the MTOW for the 7E7-9 was projected to be 227t. That left 25t of MTOW growth for a "7E7-10", which should have been enough to account for the extra OEW while still offering ~8000nm range (at 8-abreast Economy).

As structural weight grew and customers made the switch to 9-abreast Economy and planned to put in more modern and heavier premium cabins, Boeing ate up that entire surplus with the 787-9. So the only way to get more range out of the 787-10 is to up the TOW.
 
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BoeingVista
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 6:07 pm

Quoting Stitch (Reply 45):
As structural weight grew and customers made the switch to 9-abreast Economy and planned to put in more modern and heavier premium cabins, Boeing ate up that entire surplus with the 787-9. So the only way to get more range out of the 787-10 is to up the TOW.

And thrust requirements. Yes, basic physics.

Quoting Stitch (Reply 45):
When Boeing launched the 7E7, the MTOW for the 7E7-9 was projected to be 227t. That left 25t of MTOW growth for a "7E7-10", which should have been enough to account for the extra OEW while still offering ~8000nm range (at 8-abreast Economy).

Well the 787-9 is now topping 250t so its eaten the MTOW growth margin for the 10 and then some, so are we agreed that the 787 design was short sighted?

Boeing did not ask the engine OEM's to design with that magnitude of weight growth in mind, they were expecting to power a 250t 787-10 not a 280 - 300t one and that I think is an Elephant yet to be dealt with. If we use 280t thats 12% more weight than the 789, 12% on 75,000lb is 84,000lb an increase of 9,000lb; people are still freaking out about the A35J thrust bump of 4000lb which is 4.3%
BV
 
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Stitch
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 6:12 pm

Quoting BoeingVista (Reply 46):
Well the 787-9 is now topping 250t so its eaten the MTOW growth margin for the 10 and then some, so are we agreed that the 787 design was short sighted?

At the time they made the decision?

No.

Boeing wanted the 7E7 to be sized around the 767-300ER, 767-400ER and A330-200 in passenger capacity (hence focusing on a comfortable 8-abreast Economy configuration). Discussions with potential customers scaled that to the A330-200, A330-300/A340-300 and 777-200, but still with a comfortable 8-abreast Economy (I would not be surprised if 9-abreast was meant for Japanese domestic missions and charter operators).
 
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zeke
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 6:44 pm

Quoting Stitch (Reply 43):
The iteration based on what ferpe says AviationWeek believes Boeing may be working on.

We have been discussing 787-10/11/12 for over 5 years now, Boeing has taken numerous iterations to airlines.

Quoting Stitch (Reply 43):
And you were the one who noted that a six-wheel bogie is unnecessary unless you're looking at 300t or more TOW.

No I did not say that.

Quoting Stitch (Reply 43):
65m span is for the A350.

With a corresponding increase in wing area, the wing area on the A350-1000 is greater than the 77W for a lower TOW. Increase in span can reduce drag, it does not really rate a mention in the lift equation, and adding span at the tips does not tend to produce great aeroelastic results.

Quoting Stitch (Reply 43):
And a 300t 787-10 with a 65m span should need around 95,000 pounds of thrust if we use the A350-1000 as a baseline.

The 787-8/9 wing has around 1000 sq.ft less wing area than the A350-1000.
We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
 
ferpe
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RE: 787-10X To Have 6 Wheel MLG

Mon Dec 03, 2012 7:07 pm

Quoting zeke (Reply 42):
My understanding is the -9 is lower pressure than the -8, different tyre ?

According to CM yes, the 787-9 have larger wheels and they might be more spread then the -8. They certainly take more place then the -8, the MLG roof had to be raised for the -9.

Here now the tire pattern and data from the A359 ACAP (left) and 788 ACAP (right). As one can see there is a considerable difference in the size of the boogie, the 359 covering 3.5 m2 vs about 2 m2 fr the 788, the A350 covers 82% more surface with 1400*533, 240 PSI tires vs 1250*508, 230 PSI tires. Don't have the 789 dimensions but will search for it (click on the picture to see the data better):

http://i298.photobucket.com/albums/mm262/ferpe_bucket/A350788bogiespattern.jpg
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