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rotating14
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Interesting B-777-x Developments

Thu Jul 26, 2012 5:13 pm

Hello all,

I ran across this article regarding the new line up Being is planning to offer. What caught my attention is the wingspan that the 777-9x is going to be the largest at 233.4 feet. Equally interesting the elimination of the "over the wing exit" to shave 1000 pounds. Just wanted to share with the rest of us aviation enthusiasts.

http://www.aspireaviation.com/2012/0...chooses-largest-wingspan-for-777x/
 
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Stitch
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 5:31 pm

I see Pratt is looking to offer the GTF.

And Boeing continues to explore Al-Li for the fuselage.
 
LAXDESI
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 5:56 pm

In the thread linked below, I had assumed 234 feet wingspan based on a flightglobal article. 777-9X, even with 234 feet wingspan, has higher wingloading than A359 if my wingarea estimates for A359 and 777-9X are correct. 777-9X has less powerful engines normalised for MTOW. Numbers from the OP of the linked thread.
A350-100 Versus B777-9X(407 Seats) Analysis (by LAXDESI Mar 4 2012 in Tech Ops)

....................................A3510.......................B777-9X
Fuselage Length..............242..........................249 feet
Fuselage Width.................19.6........................20.33
Wingspan.......................213..........................234
Wingarea......................4767.........................5050 sq. feet(my estimate)
Seats(3 class).................350..........................407 (210 lbs. per passenger/baggage)


MTOW.....................679,000....................753,000 lbs.
MZFW......................485,000...................525,000
OEW........................335,000...................375,000 (my estimates)
MSP.........................150,000...................150,000
Design Range................8,400.....................8,200 nm (passenger only, and zero cargo)
List Price........................$309......................$320(?) million
Engine Thrust..............97,000...................99,500 lbf

Ratois
OEW/MTOW.....................0.49...........................0.50
OEW/MZFW......................0.69...........................0.71
MTOW/Wingarea............143............................149 (777 has higher wingloading)
MTOW/Thrust....................3.50...........................3.78 (A350-10 has more powerful engines normalised for MTOW)
 
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 6:16 pm

Is it known whether this wingspan will apply to all 777-X variants, or just the -9? If it's a standard wing for all models then I can see it being problematic - as the article states such a span pushes the aircraft up into ICAO Code F. That's going to limit where and how frequently it can be used unless infrastructure is modified. Of course the folding wing option would solve that, which would be an interesting solution.


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Stitch
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 7:11 pm

Honestly, even though it will be a Code F airplane, integrating it into airports might not be that much of an issue.

It will still fit in an 80x80m box and with no outboard engines and the natural upward sweep, there will be no worries with FOD or clearance with runway/taxiway signage.

The only real concern I can see will be clearing other planes on the ramp during taxiing, but since one would expect a 777-9 to be only used at international gates, which are designed for large planes (747 / A380), again, it can probably be okay.
 
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 9:29 pm

Quoting Stitch (Reply 5):
The only real concern I can see will be clearing other planes on the ramp during taxiing, but since one would expect a 777-9 to be only used at international gates, which are designed for large planes (747 / A380), again, it can probably be okay.

Yes, this and parking (especially) would be the issue. The 777, 744, 340, 330 etc... are all code E and can be accommodated by a 65/70m wide stand - even the 748i can just squeeze in to the larger so long as taxiway separation permits access. Because of this the majority of wide body stands are 70m, it's only A380 stands which need to be wider. So if carriers like BA, CX, JL, NH etc... were to opt for the 71.14m wide 777X in any number, then their respective hubs (including LHR's new T5 - most stands are 70m wide or under) would have to be reconfigured. That's a huge pain in the ass, to put it very mildly, and I can't see how it won't impact significantly on sales when the competition (A350) will be capable of using current infrastructure.

Quoting Stitch (Reply 5):
It will still fit in an 80x80m box and with no outboard engines and the natural upward sweep, there will be no worries with FOD or clearance with runway/taxiway signage.

Agreed regarding the sweep, but at most airports you can still count the number of 80m wide stands on your fingers - the notable exceptions mostly being home hubs for A380 fleets.

I don't see how the expectation that hundreds of airports worldwide will upgrade what, thousands of stands (presuming the 777X will be as successful as the current 777), is a sensible approach.


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flyingcello
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 10:14 pm

Generally aircraft park straight in to the gate...but if the aircraft comes into the gate at a slight angle, say 15 degrees off straight, the effective width required reduces significantly. So take a 72m span 779X, angle it by a few degrees, and it will fit into a 70m wide stand. A little lateral thinking?

See gates 4,5,6 and 7 at BHD as a simple example...in this case 6 and 7 can accomodate either straight in or slant stands.

http://www.ead.eurocontrol.int/eadba...EG_AD_2_EGAC_2-2_en_2012-03-08.pdf

[Edited 2012-07-26 15:27:46]

[Edited 2012-07-26 15:29:25]
 
roseflyer
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 10:19 pm

Quoting PlymSpotter (Reply 5):
That's a huge pain in the ass, to put it very mildly, and I can't see how it won't impact significantly on sales when the competition (A350) will be capable of using current infrastructure.

The article said the following:

Boeing was previously studying 4 wingspan options for the 777-9X – 65m (213.3ft) with winglets, 68.6m (225ft) with winglets, 71.1m (233.4ft) with 787-styled raked wingtip, and a 233.4ft option featuring a folding wingtip before settling on the largest one.

Could we see a folding wingtip to solve that problem?
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 10:24 pm

Quoting PlymSpotter (Reply 5):
I don't see how the expectation that hundreds of airports worldwide will upgrade what, thousands of stands (presuming the 777X will be as successful as the current 777), is a sensible approach.

I'm going to hazard a guess that Boeing has chosen this length because carriers have not objected to it. So that implies they have plans for integrating such a plane into their ground operations, either by making modifications or operating it at airports that are "A380 ready", which would mean they are also "777-9 ready".
 
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 10:44 pm

There are many airports that are already in complience with ICAO Code F/FAA ADG VI. Any airport that handles the A-380-800 or B-747-8I will be able to handle the B-777-X. Both of the current VLAs fit into the 80m X 80m gate box and so will the B-77X.
 
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RE: Interesting B-777-x Developments

Thu Jul 26, 2012 11:54 pm

It seems to me that Boeing is already going to be modifying this new 777 a lot. Al-Li alloy, new CFRP wing, new engines, new fuselage lengths, new interior. The difference between this 777X and its predecessor is going to make the difference between the 741 and the 744 look like nothing.

Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:09 am

Quoting Stitch (Reply 8):

If we go back to the very first article on the 777x published earlier this year, it's says that the most ideal 233.4ft wing would feature the folding wingtips. With that it would remain a code E aircraft and only turn code F when entering the runway as the tips unfold. I don't see this as ever being an issue since they have already said it would remain code E.
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:12 am

Quoting flightsimer (Reply 11):
If we go back to the very first article on the 777x published earlier this year, it's says that the most ideal 233.4ft wing would feature the folding wingtips. With that it would remain a code E aircraft and only turn code F when entering the runway as the tips unfold. I don't see this as ever being an issue since they have already said it would remain code E.

How much weight would that add? How would you absolutely positively ensure that the tip won't break off in flight? How much extra reinforcement will that require?
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Stitch
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:12 am

Quoting DocLightning (Reply 10):
Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?

From a technological standpoint, yes.

However, such a plane would probably not be ready until the mid to late 2020s and at that point, Airbus would already have secured the bulk of the 777-300ER replacement market with the A350-1000.

So Boeing would be in the positon then that Airbus is in now with the A350-1000 - airlines with hundreds of new planes that they're in no hurry to replace.

With the 787-10, 777-8 and 777-9, they can offer similar delivery positions to the A350-900 and A350-1000.
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:17 am

Quoting DocLightning (Reply 12):
How much weight would that add?

A lot. Folding mechanisms are heavy. But, if the increased span drops the drag enough to pay for the weight increase, it's a net win on performance.

Quoting DocLightning (Reply 12):
How would you absolutely positively ensure that the tip won't break off in flight?

The same way you absolutely positively ensure that the wing won't break off in flight...you don't.

Tom.
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:18 am

Quoting DocLightning (Reply 12):

I haven't looked for the link, but it was either in it or it was posted by someone here in. The discussion... But I think it said, that the technology is here today to allow it without extensive excess weight being added. Remember, the original 777 had them as an option but no one ever took it.
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:25 am

Quoting flightsimer (Reply 11):
If we go back to the very first article on the 777x published earlier this year, it's says that the most ideal 233.4ft wing would feature the folding wingtips.

Isn't it true, more or less, that the airlines never ordered this option for the current generation of 777s because of the added weight and maintenance needs for the folding mechanism?

I would think that the airlines, if given the option, would rather have a lighter plane with a longer wingspan and less maintenance requirements than a heavier plane with a smaller wingspan. ....all provided that they have adequate gate space when and where needed for the larger wingspan.
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queb
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:27 am

A new Al-Li fuselage is very unlikely because it would require a complete redesign (a cleansheet a/c) to take full advantage of weight gain, unless that's the objective of Boeing (to launch a brand new aircraft)
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:36 am

Quoting DocLightning (Reply 10):
Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?

There is still a great deal of the present 777 that will stay unchanged, just as was the case with the 737NG and the 748 projects. A clean sheet would be at least 3 times the cost, and much more time. The time is the biggest issue, as Stitch pointed out.

Quoting queb (Reply 17):
A new Al-Li fuselage is very unlikely because it would require a complete redesign (a cleansheet a/c) to take full advantage of weight gain, unless that's the objective of Boeing (to launch a brand new aircraft)

As I understand it, Al-Li can be substituted (with proper considerations) for Al. This means the structural design is much the same-it is just a material substitution. Not trivial, but a lot less than a clean sheet design. CFRP requires a complete new structure.
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:40 am

Quoting flyingcello (Reply 6):
Generally aircraft park straight in to the gate...but if the aircraft comes into the gate at a slight angle, say 15 degrees off straight, the effective width required reduces significantly. So take a 72m span 779X, angle it by a few degrees, and it will fit into a 70m wide stand. A little lateral thinking?

I'm afraid it doesn't work like that - aircraft park nose in because it takes up the least amount of lateral space along the terminal front. A 70m wide stand offset at a 15 degree angle would take up an extra 7m of lateral space, making the problem worse, not better.

Quoting flyingcello (Reply 6):
See gates 4,5,6 and 7 at BHD as a simple example...in this case 6 and 7 can accomodate either straight in or slant stands.

These stands are not designed to save lateral space, as per above they would increase it. They are designed to accommodate the A321 (44.5m length) at an angle so that it fits more comfortably on BHD's 45m x 40m stands.

Quoting Roseflyer (Reply 7):
Could we see a folding wingtip to solve that problem?

I think that could be quite likely, perhaps as an option. Wouldn't be the first time either.

Quoting Stitch (Reply 8):
I'm going to hazard a guess that Boeing has chosen this length because carriers have not objected to it. So that implies they have plans for integrating such a plane into their ground operations, either by making modifications or operating it at airports that are "A380 ready", which would mean they are also "777-9 ready".

That or they are still testing the water. I can see it won't be a problem for airports like DXB, DOH, AUH and I expect their home carriers are having a big amount of input.

Quoting KC135TopBoom (Reply 9):

There are many airports that are already in complience with ICAO Code F/FAA ADG VI. Any airport that handles the A-380-800 or B-747-8I will be able to handle the B-777-X. Both of the current VLAs fit into the 80m X 80m gate box and so will the B-77X.

But these 80m x 80m stands are not that common - I doubt they are provided by even half of the airports which currently have 777 services, or A330/340/747 which may potentially be replaced by a 777X.


Dan  
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PlymSpotter
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:42 am

Quoting flightsimer (Reply 11):
If we go back to the very first article on the 777x published earlier this year, it's says that the most ideal 233.4ft wing would feature the folding wingtips. With that it would remain a code E aircraft and only turn code F when entering the runway as the tips unfold. I don't see this as ever being an issue since they have already said it would remain code E.

That would make complete sense. Optimum wing span, same great maneuverability on the ground and no need to bash terminals about.


Dan  
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queb
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:49 am

Quoting SEPilot (Reply 18):
As I understand it, Al-Li can be substituted (with proper considerations) for Al. This means the structural design is much the same-it is just a material substitution. Not trivial, but a lot less than a clean sheet design. CFRP requires a complete new structure.

You can substitute a standard alloy skin with an al-li skin (same thickness, same dimensions, etc) but the weight gain will not be optimized. Al-li is a lot more expensive than standard aluminum alloys, the optimization of weight gain, ie adjust the thickness and dimensions of parts such as skins, frames and stringers, is absolutely necessary to offset the cost of metal.

[Edited 2012-07-26 17:50:12]

[Edited 2012-07-26 17:52:11]
 
queb
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:56 am

Quoting SEPilot (Reply 18):
As I understand it, Al-Li can be substituted (with proper considerations) for Al. This means the structural design is much the same-it is just a material substitution. Not trivial, but a lot less than a clean sheet design. CFRP requires a complete new structure.

If it were that easy, all manufacturers, including Airbus with neo, Boeing with MAX and Embraer with E-Jet G2 would change for Al-Li. Even Mitsubishi chose a standard alloy for the MRJ
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 1:22 am

That sure does sound like a really expensive re-do.

Wouldn't a 260' Long 787- 11x seat just as many as a 250' long 777-9X and have more Cargo room?

I'm guessing it should weigh a lot less than a 777-9x, meaning a 65m wing would be fine making it fit in Existing Code E gates.

It would require a new center section/wing (30' longer in length) and longer front landing gear. Basically use the front and rear sections from the 787-10 and just redo the center. As it is longer I would guess the Tail size should be okay.

They just spent billions on the new 787 systems and manufacturing process - why not build further on that work rather than reinventing the 777 at great cost.

This seems to me to be the better option and I can't see it gaining 200,000 lbs (difference in weight between 787-9/10 and 777-9x) be stretching it 30', so it should have a lower thrust requirement(85-90,000lbs which there are some great options available or will be available) and be better on fuel than the 777-9x.

By 2019 they should be able to crank out a lot of 787's from there 3 FAL's, convert the 777 line once production ends and you could have close to single aisle output.

What am I missing? Wouldn't this be cheaper to develop than what they are envisioning?
 
ghifty
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 1:38 am

Quoting SEPilot (Reply 18):
CFRP requires a complete new structure.

In layman's terms, why?
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tdscanuck
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 1:43 am

Quoting morrisond (Reply 23):
I'm guessing it should weigh a lot less than a 777-9x, meaning a 65m wing would be fine making it fit in Existing Code E gates.

You can't get something for free. If it has the same payload and range capability as the 777-9X then it has to be about the same weight. If it doesn't have the same capability the it's not an equivalent product.

Quoting morrisond (Reply 23):
It would require a new center section/wing (30' longer in length) and longer front landing gear.

You'd already have rotation problems with a 787 that long; lengthening the nose gear will only make that worse. It's doubtful the thing could rotate for takeoff without all new gear.

Quoting morrisond (Reply 23):
By 2019 they should be able to crank out a lot of 787's from there 3 FAL's, convert the 777 line once production ends and you could have close to single aisle output.

The 787 supply chain isn't capable of the combined 777+787 production rate. It could be, but the capital investment would be massive.

Quoting morrisond (Reply 23):
What am I missing? Wouldn't this be cheaper to develop than what they are envisioning?

The 787 gear can't support that much weight (more correctly, airport pavement can't take that much weight coming through 8 wheels). You'd need to make the 787 a triple-axle gear like the 777. That means an all new center wing box and wing structural design. You need new engines either way (the existing 787 engines don't go that large). You have rotation problems. You have drag problems (the wing loading would be really high). Everything that you'd have to do to the 777 you'd also have to do to the 787, only worse.

Tom.
 
SWALUV
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 2:31 am

Interesting they are considering the 777 with winglet that we be a nice looking airplane.   
 
JAAlbert
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 2:53 am

Quoting DocLightning (Reply 10):

Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?
Quoting SEPilot (Reply 18):
CFRP requires a complete new structure.

I realize the 777-x is an update not a clean sheet design, but when it does come time to do the clean sheet Y-3 aircraft, What is Boeing's attitude towards CFRP construction and the other features of the 787 (bleedless engines, etc)? Boeing had been saying several years back that CFRP was the way of the future, but now you don't hear so much about it. I wonder whether CFRP and the other features are living up to Boeing's expectations?
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:11 am

Quoting Stitch (Reply 4):
The only real concern I can see will be clearing other planes on the ramp during taxiing, but since one would expect a 777-9 to be only used at international gates, which are designed for large planes (747 / A380), again, it can probably be okay.

Would it help if they wasn't parked right next to each other . A 777x that is just a little bit too big for its box next to one that is somewhat smaller than what the box allows?
 
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DocLightning
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:40 am

Quoting SEPilot (Reply 18):
A clean sheet would be at least 3 times the cost, and much more time.

Would it? Yes, it would require an entirely new structure. That's the point. But they're already doing the wings basically from scratch with the materials switch. The engines are being re-done. They can scale the systems architecture directly from the 787 and they have the CFRP experience to design bigger barrels to do a new fuselage.

The bigger issue is time. And I suppose it is true that they would be conceding the 250-350 seat market to Airbus completely in the near-term if they did this.

Quoting tdscanuck (Reply 14):
The same way you absolutely positively ensure that the wing won't break off in flight...you don't.

That's not what I mean. I mean that having a spar that's meant to break some distance out from the midline is going to be heavy and difficult to design to meet ultimate load tests. Not insurmountable, I'm sure, but heavy, expensive, and difficult. That's why I doubt we'll see folding tips.

Quoting PlymSpotter (Reply 19):
I can see it won't be a problem for airports like DXB, DOH, AUH and I expect their home carriers are having a big amount of input.

I'm sure they are. The trouble is that EK, EY, and QR all fly to airports other than their home. And if they can't fly those planes anywhere, then they're worth scrap.

When Airbus started marketing the A380, Boeing's favorite marketing strategy for the 748i was to point out that their product could fly to so many more airports than A's. The 778/9X will be smaller aircraft (capacity-wise) than the A380 and so will probably be used to a wider variety of markets. This sort of wingspan might limit the available markets enough to hit sales.
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spink
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 4:16 am

Quoting DocLightning (Reply 29):
That's not what I mean. I mean that having a spar that's meant to break some distance out from the midline is going to be heavy and difficult to design to meet ultimate load tests. Not insurmountable, I'm sure, but heavy, expensive, and difficult. That's why I doubt we'll see folding tips.

The spars really shouldn't be the issue. The issue will be the weight added for the rotation and latching mechanism. The folding tip would require likely a relatively beefy motor and screw jack mechanism to lift up the 12ft or so of wing. Then you have the hinge mechanism which will add weight. Then you have effectively a double set of ribs, one on the main wing and one right on the folding tip interface, both of which will need to be stronger than a normal rib as they have to support the weight of the folding wing. Then finally you have the likely electrically engaged locking mechanism. Realistically, you are probably looking at 500-1000 lbs of additional weight per wing plus the loss of somewhere between 1-2 K gallons of fuel.
 
UA933
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 6:25 am

Question: Why would Boeing put engines on the 779 that have less power then the current 77W?

Quoting LAXDESI (Reply 2):
united - It's time to fly!
 
BMI727
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 6:48 am

Quoting DocLightning (Reply 10):
Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?

I think it absolutely would. Boeing could launch it during the middle of this decade and have it in service in the early to mid 2020s. With the A350, particularly the -1000, sliding backwards, the window gets bigger for Boeing. And I can't see the 777X being especially successful. Emirates will buy a buttload, but they'll buy a buttload of 777-300ERs too if Boeing goes with the Y3. Some other airlines will like it too, but Boeing would still be doing a lot of work to get a plane that is going to rely on having more seats to get close to cost parity with the A350-1000. It's not like they will have problems keeping the 777 line moving until a Y3 is ready, although not at a high rate necessarily but I doubt it would be worse than the 767 during the 787 development.

Quoting UA933 (Reply 31):
Question: Why would Boeing put engines on the 779 that have less power then the current 77W?

Weight reductions, or at least a weight increase that is minimal for the size increase due to new materials plus a big ass wing.
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brindabella
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 7:10 am

Quoting Stitch (Reply 13):
With the 787-10, 777-8 and 777-9, they can offer similar delivery positions to the A350-900 and A350-1000.
Quoting tdscanuck (Reply 25):
The 787 supply chain isn't capable of the combined 777+787 production rate. It could be, but the capital investment would be massive.

Indeed, with the mooted 14/month 787 output, the 787+777X should be able to offer better delivery by a handy margin.

Does anyone have any thoughts about the 777X development being "and" or "or" the 777-300+ I see being mentioned?
Billy
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 7:57 am

Quoting DocLightning (Reply 12):
How would you absolutely positively ensure that the tip won't break off in flight?

Same way you design every part of an airplane's structure.

Quoting flightsimer (Reply 15):
Remember, the original 777 had them as an option but no one ever took it.

My understanding was that the original folding wing would have folded inboard of the aileron, so a substantial increase in complexity and the loads which would have to go through the structure and mechanism. It would still be non-trivial, but I could see how a trade study could come out favourably if only the raked tips had to fold. If they used raked tips with similar dimensions to the current tips then that would be enough to get you under the class E wingspan.

Quoting queb (Reply 17):
A new Al-Li fuselage is very unlikely because it would require a complete redesign (a cleansheet a/c)
Quoting queb (Reply 21):
the optimization of weight gain, ie adjust the thickness and dimensions of parts such as skins, frames and stringers, is absolutely necessary to offset the cost of metal.

The work required to re-gauge is not even close to that of a clean sheet design. Even without a change in material there would be plenty of re-gauging.
 
DrColenzo
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 8:41 am

Quoting Stitch (Reply 13):
Quoting DocLightning (Reply 10):
Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?

From a technological standpoint, yes.

However, such a plane would probably not be ready until the mid to late 2020s and at that point, Airbus would already have secured the bulk of the 777-300ER replacement market with the A350-1000.

Quite true and this does look like the commercial policy that Boeing is going to pursue; treat the A350 as a fait accompli in the early model 777 replacement market, wring out the last drops of commercial potential from the 777 family and make a decision on a clean sheet aircraft sometime in the 2020s.

However, it also provides for a 737NG or MAX option as the 777 has a rather excellent commercial position and prospects at the moment and that might remain the case with successive re-engine, weight dropping and technology updating once every 15 years or so. Would cost a lot less than a clean sheet design.

For the record, we discussed the future for VLA's in a thread recently and it appears that Boeing with these plans for the 777-x has rendered many of the arguments for large, four engine aircraft mute....  

As for Ai-Li my understanding is that whilst some parts could be substituted over time, the process does require time, money and much more of a redesign than just taking one part out and adding an identical one of a new material.
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 9:03 am

This upgrade sounds expensive and complicated to me, and mission creep is a real risk (it's all a bit Trigger's broom), personally I'd either do a small upgrade (as in the 737MAX) or an all new plane. Indeed, when the 787 has theoretically defined the next generation of Boeing airliners, it's slightly awkward that Y1 and Y3 are a long way off.

I don't see the problems with producing an all new Y3 with a slight time delay, the A3510 is hardly flying off the shelf, and those airlines with massive fleets of 77Ws are hardly likely to dump them and replace them with A3510s in the meantime, especially if Y3 will potentially be alot more capable.
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StickShaker
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 9:06 am

Quoting DrColenzo (Reply 35):
Quite true and this does look like the commercial policy that Boeing is going to pursue; treat the A350 as a fait accompli in the early model 777 replacement market, wring out the last drops of commercial potential from the 777 family and make a decision on a clean sheet aircraft sometime in the 2020s.
Quoting DrColenzo (Reply 35):
Quoting Stitch (Reply 13):Quoting DocLightning (Reply 10):
Would it not make sense at this point to go clean-sheet, bust out the CFRP and all-electric architecture from the 787, and build a proper Y3?

From a technological standpoint, yes.

However, such a plane would probably not be ready until the mid to late 2020s and at that point, Airbus would already have secured the bulk of the 777-300ER replacement market with the A350-1000.
Quite true and this does look like the commercial policy that Boeing is going to pursue; treat the A350 as a fait accompli in the early model 777 replacement market, wring out the last drops of commercial potential from the 777 family and make a decision on a clean sheet aircraft sometime in the 2020s.

Historically, Boeing have only launched clean sheet designs when they have had no other choice, when no further derivative could do the job required. They dragged their feet launching the 777 and only did so after major customers such as BA threatened to go out and buy 330's. Similarly, the 787 was only launched when it was abudantly clear that the 767 could no longer compete with the 332. Its just not part of Boeings DNA to jump early into launching a new platform when there are other commercially viable options available - which is definately the case with the 777X.

I also suspect that Boeing may presently be even more conservative than usual about launching Y3 due to the extended timeframe required for the 787 program to break even. Even Boeing dont have unlimited sources of funding and what they have is no doubt considered better shared amongst the 789/10 along with the 737 MAX and then 777X.

There would also be the desire to benefit from the learning curve of the 787 in terms of manufacturing and in service data before commiting to such a massive program as Y3.

Regards,
StickShaker

[Edited 2012-07-27 02:10:19]

[Edited 2012-07-27 02:11:27]
 
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EPA001
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 11:06 am

Quoting morrisond (Reply 23):
That sure does sound like a really expensive re-do.

It is a really expensive re-do. But that is what is necessary to get close to the fuel burn on a per seat basis the A350-1000 will be offering. Boeing knows how good the A350-1000 will be and I am convinced that they will get very, very close to that fuel burn target. And they can offer higher capacities for the airlines who need it. I guess though that not to many airlines will go for the capacity increase, most will phase out their B747's for the B779-X. Hence why I believe we will see many fleets operating and the B787, and the A350 and B779-X.  .

Quoting UA933 (Reply 31):
Question: Why would Boeing put engines on the 779 that have less power then the current 77W?

Because the wing area will generate much more lift. So they need a lot of less speed to create enough lift to get of the ground. Basically following the principle Airbus has been using on the A330-A340 and A380 and what Airbus will be using on the A350. That principle is more economical, and also reduces the engine noise.  .
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 11:15 am

Quoting queb (Reply 21):
You can substitute a standard alloy skin with an al-li skin (same thickness, same dimensions, etc) but the weight gain will not be optimized. Al-li is a lot more expensive than standard aluminum alloys, the optimization of weight gain, ie adjust the thickness and dimensions of parts such as skins, frames and stringers, is absolutely necessary to offset the cost of metal.
Quoting queb (Reply 22):

If it were that easy, all manufacturers, including Airbus with neo, Boeing with MAX and Embraer with E-Jet G2 would change for Al-Li. Even Mitsubishi chose a standard alloy for the MRJ
Quoting ghifty (Reply 24):

In layman's terms, why?

As I said, it is not trivial; this is what I was referring to. But the basic layout of structural supports would be the same; the sizes of the skin sheets would be the same, and the locations for fasteners would be the same. Going to CFRP means that the basic structure would be completely different.

Quoting JAAlbert (Reply 27):
Boeing had been saying several years back that CFRP was the way of the future, but now you don't hear so much about it. I wonder whether CFRP and the other features are living up to Boeing's expectations?

I think they still believe it; it is just that they do not have time right now to design a new plane without losing too much market share. That is why they went with the MAX instead of the NSA.

Quoting DocLightning (Reply 29):
Would it? Yes, it would require an entirely new structure. That's the point. But they're already doing the wings basically from scratch with the materials switch. The engines are being re-done. They can scale the systems architecture directly from the 787 and they have the CFRP experience to design bigger barrels to do a new fuselage.

It is still a massively larger project to go clean sheet rather than doing a derivative.
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:26 pm

Quoting tdscanuck (Reply 25):
Quoting morrisond (Reply 23):
I'm guessing it should weigh a lot less than a 777-9x, meaning a 65m wing would be fine making it fit in Existing Code E gates.

You can't get something for free. If it has the same payload and range capability as the 777-9X then it has to be about the same weight. If it doesn't have the same capability the it's not an equivalent product.


Quoting morrisond (Reply 23):
It would require a new center section/wing (30' longer in length) and longer front landing gear.

You'd already have rotation problems with a 787 that long; lengthening the nose gear will only make that worse. It's doubtful the thing could rotate for takeoff without all new gear.

Quoting morrisond (Reply 23):
By 2019 they should be able to crank out a lot of 787's from there 3 FAL's, convert the 777 line once production ends and you could have close to single aisle output.

The 787 supply chain isn't capable of the combined 777+787 production rate. It could be, but the capital investment would be massive.


Quoting morrisond (Reply 23):
What am I missing? Wouldn't this be cheaper to develop than what they are envisioning?

The 787 gear can't support that much weight (more correctly, airport pavement can't take that much weight coming through 8 wheels). You'd need to make the 787 a triple-axle gear like the 777. That means an all new center wing box and wing structural design. You need new engines either way (the existing 787 engines don't go that large). You have rotation problems. You have drag problems (the wing loading would be really high). Everything that you'd have to do to the 777 you'd also have to do to the 787, only worse.

Tom.


I was envisioning a new Wing Center Section to give the increase in length and allow longer gear - Wing Span may need to go higher than 65M, but assuming this bird could be lighter and more efficient (smaller cross section = less drag plus potentially less weight), maybe not as wide a wing as 777-9x.

Still wouldn't this potential plane with 260' in length and potentially lower thrust requirements than 777-9x be more efficient and have more cargo space than the mooted 777-9x?

By 2018 there 3 787 FAL's should be able to crank out well in excess of 20 frames per month.

Ignoring development cost is this potential plane more efficient than A350-1000?
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 12:35 pm

Quoting SEPilot (Reply 39):
As I said, it is not trivial; this is what I was referring to. But the basic layout of structural supports would be the same; the sizes of the skin sheets would be the same, and the locations for fasteners would be the same. Going to CFRP means that the basic structure would be completely different.

It's doable but it's not financially sustainable
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 1:36 pm

Quoting queb (Reply 41):
It's doable but it's not financially sustainable

That is a question I do not have enough information to answer, and I suspect that only Boeing insiders do. All decisions on what to do with the 777 will have to undergo cost-benefit analysis, and presumably the Boeing people doing that will make good decisions. But whatever they do, they MUST make the 777x competitive with the A3510, or they are wasting their time and money. So they may end up doing some things that are hugely expensive but provide relatively small gain, just to cross that threshold. The A346 proved that in today's market no amount of discounting or soft soap will sell an aircraft that is significantly inferior to its rival in economics.
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rj777
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 2:10 pm

Quoting StickShaker (Reply 37):
Historically, Boeing have only launched clean sheet designs when they have had no other choice, when no further derivative could do the job required. They dragged their feet launching the 777 and only did so after major customers such as BA threatened to go out and buy 330's. Similarly, the 787 was only launched when it was abudantly clear that the 767 could no longer compete with the 332.

So, in other words, we'll have to wait quite a while for the 797.
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:13 pm

Quoting rj777 (Reply 43):
So, in other words, we'll have to wait quite a while for the 797.

Actually, I have a bit different take. Boeing has been reluctant to undertake new planes strictly because of the huge risk involved. They are now in a much more competitive environment than they have had since the 1960's, when they wrested dominance in air transports from Douglas. They have launched new aircraft since then largely when they had a compelling reason to; the 757, 767, and 777 were all launched in response to market demand; I question StickShaker's assertion that the 777 was launched reluctantly. They are in a whole new ballgame now; this is the first time since they gained market dominance that they have lost it, and they are being challenged on every front with better planes than they currently have. It was very clear that they would have much preferred to launch the NSA rather than the MAX; but they couldn't because too many customers would have bolted. I believe the same may apply here; I think they would rather launch Y3 than do the 777x, but they simply cannot afford the time.
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:30 pm

Quoting DocLightning (Reply 12):
How would you absolutely positively ensure that the tip won't break off in flight? How much extra reinforcement will that require?

It depends on how much of the wing would fold. If it includes the slats and outboard aileron, then the mechanism is quite complicated because you also have to pivot control surfaces, actuation and hydraulic plumbing. That’s not a small task. You also have to have the hinge be able to react the loads of the aileron which significantly increases weight.

However if you only pivot the wing outside of the slats/aileron the mechanism is essentially a large two position ground spoiler. The mechanisms behind control surfaces are far more complex as they are dynamic moving surfaces rather than a two position surface that would have a secondary locking feature.

In general, ailerons aren’t falling off with any regularity, so I wouldn’t be worried about a folding wing, although the airplane would likely still remain airworthy with the wingtip removed since that would decrease the structure supporting it.
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:33 pm

Quoting Roseflyer (Reply 45):

It depends on how much of the wing would fold. If it includes the slats and outboard aileron, then the mechanism is quite complicated because you also have to pivot control surfaces, actuation and hydraulic plumbing

Boeing has stated that if they go for folding wings it will be the wingtip only, with no control surface involvement.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:45 pm

Quoting UA933 (Reply 31):
Question: Why would Boeing put engines on the 779 that have less power then the current 77W?

Because the 777X will have a lighter MTOW than the 77W/77L as well as a much bigger wing that produces more lift.
 
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EPA001
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:49 pm

Quoting seabosdca (Reply 47):
Because the 777X will have a lighter MTOW than the 77W/77L

About the wing I already answered the question from UA933. See reply 38.  .

I am not so sure that the B777-9X will be lighter. The plane will be significantly bigger, so even if the weight saving program is very successful, at best they will equal the weight of the B77W. But even that is a very, very ambitious goal. A relatively slight increase in weight seems much more likely. Of course on a per seat basis the B777-9X will be lighter then the B77W.
 
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Stitch
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RE: Interesting B-777-x Developments

Fri Jul 27, 2012 3:52 pm

Quoting EPA001 (Reply 48):
I am not so sure that the B777-9X will be lighter.

If it isn't, then there is no reason to launch it as it needs similar range to the 777-300ER to be effective.