Print from Airliners.net discussion forum
http://www.airliners.net/aviation-forums/general_aviation/read.main/4412476/

Topic: "Boeing Could Offer T7 Replacement"
Username: AFKL
Posted 2009-05-14 10:24:25 and read 33649 times.

Hey everyone,

I havn't seen anything posted about this yet. Just saw the article on flightglobal.com:

http://www.flightglobal.com/articles...ent-to-rival-a350-within-four.html

IMO, it would be great to see a Boeing T7 replacement and see this legacy of an airliner to continue gracing the skies, just like the 747 has done. However, it does appear from the quotes given in the article that Boeing is underestimating the abilities of Airbus with the A350, and possibly over-estimating their own. Obviously Boeing makes great aircraft, but the last time they were so over confident it turned out into this 787, I dare say, disaster of delays and underperformance. And here they continue with their parade that Airbus will only make an evolutionary progress with a completely new airliner, and Boeing can make something far superior with a existing design (albeit possible new wings and engines, though no mention of the use of composite materials), I'm not really seeing it.

Quote:
He says that "in the best case scenario [for the A350]", Boeing could "come to market within three to four years with a 777-replacement aircraft that is overwhelmingly superior to the A350".

I have my doubts, but anxious to hear what the outcome will be. In fact, I can't wait, the T7 is a beauty!


ALLARD.


edit: quote.

[Edited 2009-05-14 10:30:41]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: DL767captain
Posted 2009-05-14 10:42:52 and read 33517 times.

It shouldn't be too hard for Boeing to incorporate most of the 787 developments into a 777 replacement. The 787-10 might sound nice but it will just reach the 777-200 size. Making the 777 replacement cover the -200 would probably give it more range, especially if it was designed with the base model the size of the -300.

Boeing has to do something about the 777, more customers are going to move to the A350 because it is the only real alternative right now. If Boeing created a 777 replacement that is pretty much a larger 787 they would really have an amazing aircraft family, 787 all the ay up to the new 777

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: RedFlyer
Posted 2009-05-14 10:48:59 and read 33464 times.

Quoting AFKL (Thread starter):
However, it does appear from the quotes given in the article that Boeing is underestimating the abilities of Airbus with the A350, and possibly over-estimating their own.

I'm not sure Boeing is underestimating the abilities of the A350 as noted by the fact that they remain open to responding with a T7 replacement in the event that the A350 does turn out to be a T7 "killer". But until the A350 is proven - and that is still years away - there's no point in sinking billions of dollars into a replacement aircraft if it's not warranted. And even if it is warranted, the T7 still has many years of sales life left in her because the A350 will not be flying in appreciable numbers (meaning orders placed today are still 7 - 8 years away from delivery) for many years to come. Airlines needing a T7 class airplane today still only have one choice available to them.

Quoting AFKL (Thread starter):
Obviously Boeing makes great aircraft, but the last time they were so over confident it turned out into this 787, I dare say, disaster of delays and underperformance.

The delays are obvious. But I'm not sure "underperformance" would describe the aircraft accurately. Sure, the first few birds will be overweight and even possibly range-limited. But that's against the 787's original specs. Even an underperforming 787 will still offer benefits beyond the A330.

Your assumptions, and that of Mr. Shankland's of Airbus, assume the A350 suffers no delays and meets or exceeds its performance specs out of the gate. Possible, but not highly probable.

[Edited 2009-05-14 10:50:52]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JayinKitsap
Posted 2009-05-14 10:58:11 and read 33356 times.

IF CFRP is the future of commercial aircraft, as I suspect it is, Boeing really needs to get the 787-8 into smooth production and up to performance, take that knowledge and experience, apply that to the 787-9, and get it proven. Only then with that real experience does it make good sense to tackle the 777.

The 787 has a lot of new systems and a new manufacturing method, it will take time to gel. The Y3 will be able to scale these up effectively, but it needs a clean slate for a while.

I think this also pertains to the 737 RS.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-14 11:01:34 and read 33343 times.

When Airbus launched the A350XWB in 2007, they calculated the strongest years for 300-seaters (so A343 and B77E) would be 2017 (four years after the planned EIS of the A350-900XWB) with 110 planes retired that year. The next four years would see retirements of 90, 80, 90 and 100 planes, respectively. It would then drop to around 50 for the next three years and 40 in 2025 (the final year on the chart).

In total, Airbus projected retirements of 891 frames between 2010-2025 with each frame being retired after 20 years of revenue service. With 226 A350-900XWB sales, that means Airbus has claimed 25% of the market they expect to exist for their product over the next 15 years. So that leaves 75% currently available and I think that is a market large enough for Boeing to make a play for.

Airbus did not offer a chart on 350+ seat (777-300ER / A340-600) replacements. However, at 20 year lives, that means the ~184 77Ws already delivered will not need replacement with an A350-1000XWB until the 2024-2029 timeframe and 219 more will not need replacement until at least 2029.

I'm skeptical on Airbus' claims that the A350-1000XWB will have 25% lower block fuel and cash operating costs per seat then the 777-300ER. I also am skeptical of Airbus' comparison between the A350-900XWB and the 777-200ER. And the 777-200LR is said to have lower block fuel and cash operating costs then the 777-200ER.

Therefore, in the near-term, Boeing needs to work on reducing the MWE of the 777-200LR and 777-300ER while GE continues to improve the SFC of the GE90-11xB series. If they can also increase the MTOW to raise payload, that would help, too. In other words, they need to follow Airbus' program with the A330-200: steady improvements that, while overall still not as good as the 787-8, make a great plane even better and even more desirable.

Even if all three A350XWB models EIS on schedule and Airbus' production ramp is seamless, if traffic returns to previous levels, the 777 will de facto win orders because it will be the only model available. But the better Boeing makes it, Boeing will win more then just de facto orders.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Eightball
Posted 2009-05-14 11:05:35 and read 33290 times.

The fact is that Boeing went through a lot of work in terms of designing the 777, and now they're bringing the 787 into the market.... So I think that Boeing should just continue producing the 777 and update it if necessary.

Boeing have been keeping the 747 alive for all these years, with the 748 being the latest variant. I truly think that Boeing could keep the 777 alive for many years to come, because it's an excellent design.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-14 11:30:19 and read 33064 times.

If the changes incorporated in the 747-8's wings lead to some solid performance improvements, does anybody know how feasible it would be to implement some or all of these changes to the 777's wings?

Also, could GE introduce some of their noise-reduction developments for the GEnx (chevrons and such) to make the 777 quieter? I understand it already meets QC1 / QC2 requirements at LHR (same as the A350XWB), but every extra bit could help with airport noise curfews.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AFKL
Posted 2009-05-14 12:04:27 and read 32829 times.



Quoting RedFlyer (Reply 2):
Your assumptions, and that of Mr. Shankland's of Airbus, assume the A350 suffers no delays and meets or exceeds its performance specs out of the gate. Possible, but not highly probable.

Can we afford to assume otherwise? I do not think that Boeing can afford to base their T7 replacement model on a fact that the A350 will fail on these aspects. Although airliner programs have been delayed in the past, both A and B have learned from these delays, and knows how to minimise these at all costs.

I'm not saying that there won't be a market for a new T7, on the contrary, I think it has a lot of potential. However, to say that it will be "overwhelmingly superior" to the A350 is just nonsense when the bird hasn't even flown yet! I'm just sceptical.

Let's, howeve, try to avoid a A vs. B war.


ALLARD.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Nomadd22
Posted 2009-05-14 12:32:56 and read 32644 times.

I imagine Boeing is waiting to see how the 350 comes in weight wise. A lot of people are at a loss as to how Airbus can pull off their target weights. If it's a lot closer to the 777 than AB hoped, the chance of updated wings/engines for the Boeing is a lot better. If the 350 meets target weight and efficiency a refreshed 777 won't do the trick.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Hawkercamm
Posted 2009-05-14 12:41:17 and read 32580 times.



Quoting Stitch (Reply 4):
Therefore, in the near-term, Boeing needs to work on reducing the MWE of the 777-200LR and 777-300ER while GE continues to improve the SFC of the GE90-11xB series. If they can also increase the MTOW to raise payload, that would help, too. In other words, they need to follow Airbus' program with the A330-200: steady improvements that, while overall still not as good as the 787-8, make a great plane even better and even more desirable.



Quoting Stitch (Reply 6):
Also, could GE introduce some of their noise-reduction developments for the GEnx (chevrons and such) to make the 777 quieter? I understand it already meets QC1 / QC2 requirements at LHR (same as the A350XWB), but every extra bit could help with airport noise curfews.

I agree with this. I think A and B should draw a truce with the A330-2-3/A350-8-9-10 and B787-8-9-10/B777-2-3 and concentrate on making these aircraft incrementally better. A market exists for X amount of "medium sized" airliners per year and only A and B are in that market.
From a business point of view a truce for a number of years would allow both manufactures to cream some profit before finding $15b+ for the next long haul plane.

I would take a guess that when the next long haul aircraft come along Boeing would attack the A350XWB from above with a ~400 seater (8500nm) and A would attack the B787-8 from below with a 200-250 seater 2-class (4000-5000nm) "transcontinental".

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-14 13:17:06 and read 32358 times.

Quoting AFKL (Reply 7):
However, to say that it will be "overwhelmingly superior" to the A350 is just nonsense when the bird hasn't even flown yet! I'm just skeptical.

To make such a statement is just incredibly arrogant. I do not see any major technological breakthrough in the next 4 years that practically would make the A350 (which will not fly at an airline before 2013!) and the B787 (which also still has not flown!) practically obsolete. This statement is absolute nonsense.

Let us wait and see what the B787 and A350 will bring to the market once they are flying. And in the meantime improve the B777 where possible, because it still is a great plane. Maybe in 4-5 years Boeing goes for the B787-10/11, and maybe Airbus goes for an A350-1100. Everything is still possible at this stage. It is highly unlikely that Boeing will build a B777 successor. If they do so, it will be a plane which will start at A350-100 size (just under the current B77W), and will go on to a "B777-400" size of plane, whatever that may be. In the process the B748i is ditched too. Also that plane has not flown yet. So to make such statements is nice to make headlines, but it does not add to the credibility of the one making such foolish statements.

[Edited 2009-05-14 13:17:59]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AirbusA6
Posted 2009-05-14 13:42:05 and read 31900 times.

The 787 didn't kill the A330, which has sold in record number over the last few years. The A350 hasn't killed the 777 either, it's still the best type in current production in it's class, and the A3510 is a loooong way off.

The one plus for Airbus, is thatn their A350 development programme is a lot longer than the 787's was meant to be, so I would be surprised if it had the same delays - there's much more slack built into the timetable than the 787 programme, which was very optimistic...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AFKL
Posted 2009-05-14 14:20:13 and read 31287 times.



Quoting EPA001 (Reply 10):
Quoting AFKL (Reply 7):
However, to say that it will be "overwhelmingly superior" to the A350 is just nonsense when the bird hasn't even flown yet! I'm just skeptical.

To make such a statement is just incredibly arrogant. I do not see any major technological breakthrough in the next 4 years that practically would make the A350 (which will not fly at an airline before 2013!) and the B787 (which also still has not flown!) practically obsolete. This statement is absolute nonsense.

On the contrary. I think that Boeing making such bold statements that a T7 replacement will be, and I quote again, "overwhelmingly superior" to the A350, is quite arrogant on Boeing's part. Although there may not be major technical breakthrough's in the next coming four years (again, a fairly bold statement, based on what?), the 787/A350 are technological break-through's compared to the T7's (just think of the extensive use of composites). Therefore, if Boeing claims they can create a T7 replacement within 4 years, based on a design that is already a generation older, that will become "overwhelmingly superior" to the A350, a new generation design, seems to be quite a task! Sure, they'll slap on some new wings and engines, sure it'll pose a threat to Airbus sales, sure they'll sell well and be competitive, etc., etc... all I'm saying is that I'm quite skeptical in Boeing creating a replacement which is "overwhelmingly superior". OK, they may use 787 technology, but how is that in any part a break-through when compared to the A350? I don't really understand your comment.

Also note my use of the word "skeptical", and "I think", these are merely my (uneducated) opinions and thoughts. I am here to learn, so if you disagree or can tell me otherwise, please do!  Smile


ALLARD.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Acheron
Posted 2009-05-14 14:23:50 and read 31240 times.

I'll never understand civ-av's posters. When the A350 Mk.1 came out, lots of poster were saying that it was a joke and that a warmed over A330 would never be able to match the 787.
Now comes Boeing saying that a warmed over 777 can outperform the A350, and people go saying is entirely possible.


Anyway, that guy sounds a lot like Leahy during his golden years as a loudmouth.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: DfwRevolution
Posted 2009-05-14 14:24:38 and read 31207 times.



Quoting AirbusA6 (Reply 11):
The 787 didn't kill the A330, which has sold in record number over the last few years.

It's more accurate to say that the 787 <i>hasn't</i> killed the A330... yet. In time, the 787 - and the A350 it sparked in reply - will certainly be the reason A330 orders dry-up. This is rarely an industry where death-blows are dealt and one product suddenly falls out of favor.

Quoting AFKL (Reply 7):
(1) Can we afford to assume otherwise? I do not think that Boeing can afford to base their T7 replacement model on a fact that the A350 will fail on these aspects. (2) Although airliner programs have been delayed in the past, both A and B have learned from these delays, and knows how to minimise these at all costs.

1. Of course they can.

2. If that were the case, then presumably Boeing and Airbus would have already known their lessons long before the A380 and 787 delays. Reality is that the next programs will have different technical challenges and today's experiences won't hold all the answers. Reality is that people come and go from these engineering teams and lessons are lost.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: CARST
Posted 2009-05-14 14:35:16 and read 31012 times.

If B is planing to make a complete new 777 it could be a huge success, it remains the question would it be profitable?

I imagine something like the step from 742/743 to 744. A complete new 777, build from CFRP, and some 787 technology integrated.

If we see a 787-10 i could think of a 777-400 and -500. The 400 as 300ER CFRP-replacement and the 500 to replace the 748i (not the freighter).

Would it be possible? Would it be economical? If the program would cost about 70% of the 787 program, how many 777NGs would be needed to reach the ROI?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-14 15:02:50 and read 30588 times.



Quoting AFKL (Reply 12):
Quoting EPA001 (Reply 10):
Quoting AFKL (Reply 7):
However, to say that it will be "overwhelmingly superior" to the A350 is just nonsense when the bird hasn't even flown yet! I'm just skeptical.

To make such a statement is just incredibly arrogant. I do not see any major technological breakthrough in the next 4 years that practically would make the A350 (which will not fly at an airline before 2013!) and the B787 (which also still has not flown!) practically obsolete. This statement is absolute nonsense.

On the contrary. I think that Boeing making such bold statements that a T7 replacement will be, and I quote again, "overwhelmingly superior" to the A350, is quite arrogant on Boeing's part.

I believe that is what I said as well  Wink. We are complete in agreement here.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-14 15:05:10 and read 30562 times.



Quoting Acheron (Reply 13):
Anyway, that guy sounds a lot like Leahy during his golden years as a loudmouth.

This comment is spot on!  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AFKL
Posted 2009-05-14 15:06:58 and read 30532 times.



Quoting EPA001 (Reply 16):
I believe that is what I said as well  . We are complete in agreement here.

Sorry, I misunderstood your comment. I thought you referred to my statement as being arrogant.  Wink Hence my confusion.


ALLARD.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ruscoe
Posted 2009-05-14 15:10:26 and read 30473 times.



Quoting AFKL (Reply 12):
On the contrary. I think that Boeing making such bold statements that a T7 replacement will be, and I quote again, "overwhelmingly superior" to the A350, is quite arrogant on Boeing's part.

What this boils down to is whether the panel design of the 350 is as good as the wound fuselage of the 787.

Why? Because apart from anything to do with weight , shape or fatigue, a major attraction of the design and manufacture of the 787 fuselage, is that it can be scaled, without major redesign.
When this method of manufacture was first mooted, Boeing was saying this and I have not heard anything different.

On the other hand the large panel design of the 350, built up on an aluminium stripped CFRP frame, is not easily scaled, without a major redesign..

In practical terms it is probably more thruthfull than arrogant of Boeing to say, that if necessary, they could produce a replacement 777 within a few years. It would be a scaled 787.

Any engine which Airbus uses on the 350-1000 could if necessary be put under the wings of a new 777.

The Corporate hierachical structure of the Boeing organisation, has a long memory. I believe another implementation disaster such as the 787 has suffered is most unlikely, the next time around.

Ruscoe

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-14 15:18:55 and read 30368 times.



Quoting Ruscoe (Reply 19):
In practical terms it is probably more thruthfull than arrogant of Boeing to say, that if necessary, they could produce a replacement 777 within a few years. It would be a scaled 787.

The B787-10/11/12 which could be matched by he A350-1100 or so? But that is not a totally new airplane really replacing the B777.

Quoting Ruscoe (Reply 19):
The Corporate hierachical structure of the Boeing organisation, has a long memory. I believe another implementation disaster such as the 787 has suffered is most unlikely, the next time around.

That is true as far as I can judge it. It is also one of the reasons why Airbus planned so much less agressive their A350-development phase. They learned form the A380.  Wink

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-14 15:26:50 and read 30263 times.



Quoting RedFlyer (Reply 2):
I'm not sure Boeing is underestimating the abilities of the A350 as noted by the fact that they remain open to responding with a T7 replacement in the event that the A350 does turn out to be a T7 "killer".

The 777-200ER/LR backlog has shrunk to a few dozen.. Obviously the A330-300 / A350-900 combi silently did "kill" the 777-200 variants that were the best selling for the last 15 yrs.

I think Boeing underestimated this and had to put all its energy in the 787. I think a 787 HGW subseries could cover the segment up to 350 seats.

A 777-300 / 747-8i replacement seems inevitable if Boeing wants to remain a player in the > 350 seat segment. A dedicated 370-500 seat long hauler seems to a be a (rather big) sweetspot avoiding direct competition with Airbus. A 777-400 could be a stop gab. http://www.youtube.com/watch?v=CVWQ5h5UOfk

But then again the 737 may need some action if Airbus puts a high BPR engine under the A320, Boeing tested the market for a "Light Twin" 757/A310/767 replacement and IDS also needs some new types..

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: RedFlyer
Posted 2009-05-14 15:37:58 and read 30117 times.



Quoting AFKL (Reply 7):
Quoting RedFlyer (Reply 2):
Your assumptions, and that of Mr. Shankland's of Airbus, assume the A350 suffers no delays and meets or exceeds its performance specs out of the gate. Possible, but not highly probable.

Can we afford to assume otherwise?

I think everyone has to assume otherwise (if I understand you correctly). Airbus' most current high-profile projects (A380, A400M) have suffered from serious delays, as has Boeing's most recent offering. To assume that the A350 program will come off without a hitch is to assume something that goes against recent history for both manufacturers. The design phase, which is all that Airbus has indulged in thus far with the A350, is the easy part (relatively speaking) so it's easy for Airbus PR to make confident statements. We saw the same happen on Boeing's end with the 787. Soon Airbus will have to deliver a tangible product, and much as Boeing found out, that will take considerable effort. Until the A350 takes flight anything anyone brags about will have to be taken with some skepticism.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: MD-90
Posted 2009-05-14 15:44:13 and read 30009 times.



Quote:
Speaking in London after a Boeing financier briefing,

That says it all right there. Mr. Kostya Zolotusky (Russian?) was trying to encourage bankers to provide capital to Boeing. I think that slightly excuses his over the top hyperbole about Boeing's current and future product lines.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Par13del
Posted 2009-05-14 15:53:08 and read 29891 times.



Quoting Acheron (Reply 13):
Now comes Boeing saying that a warmed over 777 can outperform the A350, and people go saying is entirely possible.

One problem, the initial A350 model is larger than the B-787 and smaller than the B-77W which is now the only product which is carrying the sales, the LR is a niche model. For the A350 to "kill" the B-777W it will most be on economics as the current a/c will uplift more pax and can match or equal payload. Remember the A330 and B767, the A330 was larger than the B767, the A350 will not be, have to wait another few years until they go head to head.

Quoting Keesje (Reply 21):
The 777-200ER/LR backlog has shrunk to a few dozen.. Obviously the A330-300 / A350-900 combi silently did "kill" the 777-200 variants that were the best selling for the last 15 yrs.

I note the last 15 years, I asume that the B777-300 is not included in your thoughts.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-14 16:21:58 and read 29605 times.



Quoting RedFlyer (Reply 22):
Until the A350 takes flight anything anyone brags about will have to be taken with some skepticism.

The A380 went pretty well until after taking flight..

Quoting Par13del (Reply 24):
I note the last 15 years, I asume that the B777-300 is not included in your thoughts.

No, the -300ER seems to do well for now, but the 300 seater problem isn't solved by that.

Maybe John will also tell the world they can produce an aircraft that can easily outperform anything Boeing can come up with. Words are cheap..

http://www.youtube.com/watch?v=2T_IBbPbVyQ  Big grin

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-14 16:30:38 and read 30375 times.



Quoting Acheron (Reply 13):
Now comes Boeing saying that a warmed over 777 can outperform the A350, and people go saying is entirely possible.

Where is Boeing saying a warmed over 777 can outperform the A350?

They said that, depending on the outcome of the A350, there are some things they could do to the 777 to make it "competitive" but that they would also need only 4 years to replace the 777 should the A350 live up to promises and the 777 changes don't.

A look at the advancements the A330-200 has made compared to the shortfall in projected performance of the 787-8 shows that old frames can be given some new life and promises of "20% better than this or that" don't always pan out.

Had the A332 been given GenX engines, it might have been close to payload/range performance to the 787-8, though more expensive to buy and using more fuel.

Quoting Keesje (Reply 21):
The 777-200ER/LR backlog has shrunk to a few dozen.. Obviously the A330-300 / A350-900 combi silently did "kill" the 777-200 variants that were the best selling for the last 15 yrs.

The 787-9 had nothing to do with that, either? Of course not...  Wink

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-14 16:38:28 and read 30244 times.

It would be very interesting for me to know what the relative efficiencies are between the 787, 350 and 777 wings.

I believe the 777 wing was state of the art when it was created. How much has the state of the art changed since then? Do exotic materials, (like CFRP), make a significant difference to the aerodynamic performance of a wing?

If they decide to make a plastic 777, I imagine they'll do the XXWB thing. How difficult is it to scale up barrel size? Might Boeing consider a panel approach?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-14 16:48:00 and read 30180 times.



Quoting Ikramerica (Reply 26):
Quoting Keesje (Reply 21):
The 777-200ER/LR backlog has shrunk to a few dozen.. Obviously the A330-300 / A350-900 combi silently did "kill" the 777-200 variants that were the best selling for the last 15 yrs.

The 787-9 had nothing to do with that, either? Of course not...


The 787-9 is smaller / lighter. Maybe airlines want to cut capasity then?

Quoting JoeCanuck (Reply 27):
It would be very interesting for me to know what the relative efficiencies are between the 787, 350 and 777 wings

They are diffrent wings, teh A350 is optimized for bigger loads.

Quoting JoeCanuck (Reply 27):
I believe the 777 wing was state of the art when it was created. How much has the state of the art changed since then? Do exotic materials, (like CFRP), make a significant difference to the aerodynamic performance of a wing?

I don't think materials did alter shapes very much. They improved weight, fuel stowage. Introduction of Computational fluid dynamics (CFD) did more I guess.

Quoting JoeCanuck (Reply 27):
If they decide to make a plastic 777, I imagine they'll do the XXWB thing. How difficult is it to scale up barrel size? Might Boeing consider a panel approach?

Scale up changes everything & leads to a new design I guess.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-14 16:50:51 and read 30111 times.

Of course, hindsight is always 20-20 and makes any idiot look like a genius.  Smile

We should remember that until June of 2007, Airbus did not have an answer to the 777. The A345NG and A346NG were both stillborn due to lack of customer interest - those customers were all buying 77Ls and 77Ws. And upon EIS the 787-9 would have ended the need for the A340-300, resulting in the entire line effectively being shut-down due to lack of sales, as the A330 has (effectively) done with the (commercial) 767 line.

So Boeing had no reason to do anything more then vague internal studies of a 777 replacement because they owned the market and why replace a known winner with something uncertain?

The 77L is not a niche product because it's not used for the most part on niche markets - ULR ops. Over the past seven years, the 77L has sold almost as many frames as the 77E did (50 to 66). Airlines who bought the 77E the past decade were predominately those who already owned and operated the type and were topping off orders. Airlines who ordered the 77L were predominately new customers to the 777 family. For a new operator, the 77L is the better plane, whether or not you need every last kg of payload or TOW. However, the 300-seat market is pretty mature by now. All the DC-10s and MD-11s and L-1011s have been replaced with A343s and 77Es. And those planes themselves are mostly under 20 years old - itself no longer a "hard limit" on how long an airframe can be profitably kept in revenue service.

Airbus turned lemons (the A350) into lemonade (the A350XWB) no less then Boeing leveraged technologies and techniques from the Sonic Cruiser (lemon) into the 787 (lemonade). The original A350 and the Sonic Cruiser were both "shoot from the hip" responses for companies who'd become complacent with certain segments of their product line (A330 and 747) and therefore were caught somewhat napping when their competitor analyzed their strengths and developed a new model to counter it.

Airbus and Boeing both follow each others leads. Airbus developed the A300 and Boeing followed with the 767 with Airbus following with the A330 and now Boeing following with the 777. Airbus launches the A340, Boeing follows with the 777, now Airbus offers the A350XWB. Boeing will respond, either with an improved 777 (as Airbus has done with the A330) or something new (as Airbus has done with the A350XWB).

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-14 17:07:53 and read 29943 times.



Quoting Keesje (Reply 28):
Quoting JoeCanuck (Reply 27):
It would be very interesting for me to know what the relative efficiencies are between the 787, 350 and 777 wings

They are diffrent wings, teh A350 is optimized for bigger loads.

Not bigger than the 777, though.

Quoting Keesje (Reply 28):
Quoting JoeCanuck (Reply 27):
I believe the 777 wing was state of the art when it was created. How much has the state of the art changed since then? Do exotic materials, (like CFRP), make a significant difference to the aerodynamic performance of a wing?

I don't think materials did alter shapes very much. They improved weight, fuel stowage. Introduction of Computational fluid dynamics (CFD) did more I guess.

I believe the 777 was designed using computational fluid dynamics. I was wondering more how much fluid dynamics have improved since the 777...if any.

Quoting Keesje (Reply 28):

Quoting JoeCanuck (Reply 27):
If they decide to make a plastic 777, I imagine they'll do the XXWB thing. How difficult is it to scale up barrel size? Might Boeing consider a panel approach?

Scale up changes everything & leads to a new design I guess.

Scaling up doesn't necessarily change everything...depending on design. What I was asking is specifically, how well the 787 fuse technology, (mandrel, autoclave), scales up.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: CARST
Posted 2009-05-14 17:14:14 and read 29852 times.



Quoting JoeCanuck (Reply 30):
Scaling up doesn't necessarily change everything...depending on design. What I was asking is specifically, how well the 787 fuse technology, (mandrel, autoclave), scales up.

Why do you think of an up-scaled 787? Perhaps they just stay with the whole 777 design and try to make the fuselage and whole wings out of CFRP.

If that would be possible, the airplane would perhaps be 15-30% lighter, consuming much less fuel and be on eye-level with the A350XWB or even better.

Anyone know if it is possible to convert a steel-design into an CFRP-design?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-14 17:29:29 and read 29745 times.



Quoting CARST (Reply 31):
Anyone know if it is possible to convert a steel-design into an CFRP-design?

The 777 was designed on computer using CATIA and other resources, so it would likely make doing a "CFRP 777" a quicker and easier process since you can likely draw on pre-existing resources, schematics, and data.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: CARST
Posted 2009-05-14 18:00:18 and read 29370 times.



Quoting Stitch (Reply 32):
The 777 was designed on computer using CATIA and other resources, so it would likely make doing a "CFRP 777" a quicker and easier process since you can likely draw on pre-existing resources, schematics, and data.

I know that, i was thinking more about the structural loads. Isn't the question if they have to build a complete new plane if they want to use CFRP? Or can they use the 777 computer model and just make some tweaks here and there?

Kind of a question for our engineers here ... but i would like to read your opinions anyway, engineer or not... ^^

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: BoeingBus
Posted 2009-05-14 18:23:22 and read 29180 times.

This is tactical move by Boeing to distract Airbus as the are firming up the design and sending parts for fabrication... make you think twice if you have the right product. not surprised here...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-14 18:32:43 and read 29093 times.



Quoting CARST (Reply 33):
Isn't the question if they have to build a complete new plane if they want to use CFRP? Or can they use the 777 computer model and just make some tweaks here and there?

It would be an all-new plane if they wanted to go to CFRP.

It would be interesting to know the production costs, weight-savings and aerodynamic improvements of moving from Al construction to Al-Li and going with laser-welding.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Pnwtraveler
Posted 2009-05-14 18:40:34 and read 29018 times.



Quoting Stitch (Reply 32):
Quoting CARST (Reply 31):
Anyone know if it is possible to convert a steel-design into an CFRP-design?

The 777 was designed on computer using CATIA and other resources, so it would likely make doing a "CFRP 777" a quicker and easier process since you can likely draw on pre-existing resources, schematics, and data.

What Stitch is saying is backed up by a funny source. The software that designed the 777 has been modified and improved and is now being used to design and build the next generation aircraft carrier to follow the Nimitz Class. One of the benefits is that it lets the design be modified much easier. The George Bush, the last of the Nimitz Class has a number of the new features to be live tested when it enters service. I was told it is now quite easy to modify the design between ships of the class to take advantage of learning and respond to conditions because everything is online and can be tested dynamically by the computer.

So I would think with the design is in the computer already and doing modfications would be much easier than starting the design from scratch. Maybe even some of the features Newport News is using could improve the software further.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-14 18:46:48 and read 28951 times.

Quoting CARST (Reply 31):
Why do you think of an up-scaled 787?

I was just wondering which way Boeing would go. Since their experience with CFRP fuselages is the 787, I am curious how easy it would be to scale the process up to 777 sizes.

Heck, for all I know, an ali-li panel for panel replacement might be good enough.

...er...wot stitch said.

[Edited 2009-05-14 18:47:33]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: CFBFrame
Posted 2009-05-14 19:19:44 and read 28624 times.

This is a question that concerns me since both A & B have never flown a commercial CF a/c, and until the 787 flies much cannot be answered. I assume that much of the additional weight in the 787 is driven by design redundancy until flight test and actual operation allows significant design changes. Personally I support that philosophy until there is ample CF data. Given my belief (which I know will be attacked by the esteemed members of this board), could the T7 be the perfect a/c? Structural requirements needed to carry 350+ might offset the advantage of CF, which could mean a wing and engine modifications could be the only real performance gains available. Resulting in only a 3-5% improvement over the existing T7 and in the end the 350 equals that performance. I also believe that's why the 787-10 has not been given the green light because of that concern.

Stitch- what would the market implications be? Does worldwide demand devolve to equilibrium because the airlines want two suppliers, or do existing T7 owners re-up with Boeing?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Osiris30
Posted 2009-05-14 19:28:05 and read 28525 times.



Quoting Stitch (Reply 6):
Also, could GE introduce some of their noise-reduction developments for the GEnx (chevrons and such) to make the 777 quieter? I understand it already meets QC1 / QC2 requirements at LHR (same as the A350XWB), but every extra bit could help with airport noise curfews.

I think you guys all really need to listen to the IAG podcast with the VP of the GTF from PW very carefully and then re-read this thread. (It was posted in the last week or two and Jon (Flightblogger) tweet'ed a link to it).

This information was pretty much leaked by said VP over a week ago and almost no one picked up on it. I was going to start a thread on it but I figured why bother since half the forum would get their panties in a bunch over said VP saying they weren't looking at doing a 350XWB GTF, yet they were working on a GTF in the thrust class for the 777/350. It didn't take a rocket scientist to put it all together.. even the dates are there for those who want to listen (it's actually a great half an hour).

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-14 19:52:02 and read 28473 times.

Quoting CFBFrame (Reply 38):

While it is true the 787, in terms of percentage of her primary structure, is the "most CFRP" commercial airliner at the moment, both Boeing and Airbus have been using the material in a structural role for decades. The A380 has CFRP structures that, by weight or dimension (I don't remember), equal or exceed any used on the 787-8.

So while a few folks like to raise red herrings disguised as red flags about just how "safe" the 787 will be (while pointedly ignoring the implications of how "unsafe" their statements imply the A380 is) the reality is that a CFRP airframe will be no less safe then an Al one and likely to be more so.

The 787-8 ended up heavier then planned, even without the various overages. When Boeing first announced the "spec" OEW, it was 109t. They then raised it to 115t in September 2007 and we haven't heard anything since. Now that figure does include a generic three-class cabin plus various fluids and other fittings, so the actual weight of an airframe with no interior will be less. Still, it looks like a 787-8 will end up heavier then an A330-200 using Boeing's and Airbus's OEW figures.

Airbus has also admitted to the A350-900XWB being heavier then planned, though rumors are swirling that the overage is more then they publicly admitted last June (which was 2.2t). The last Airbus OEW figure of 116t (including the extra 2.2t) would be 22t less then a 777-200ER which is significant. If the actual A350-900XWB "green" weight ends up being heavier then 116t, that is going to give the 777-200ER (really, the 777-200LR) some breathing room, especially if the engine manufacturers can continue to extract SFC improvements and Boeing can improve the aerodynamics through tweaking to also improve cruise fuel consumption.

Quoting CFBFrame (Reply 38):
Stitch- what would the market implications be? Does worldwide demand devolve to equilibrium because the airlines want two suppliers, or do existing T7 owners re-up with Boeing?

All things being equal, I expect airlines and leasing companies prefer two suppliers because it provides competition which exerts a downward pressure on prices. Boeing's "lock" on the 300-400 long-range seat market with the 777 didn't mean Boeing could charge whatever they wanted, but it also meant they could exercise some pricing power. Airbus enjoyed much the same with the A330: the A330-200 had a "lock" on the 200-250 seat market and the A330-300 has a "lock" on the 300-seat medium-range market.

The A350 doesn't help customers as much as the A350XWB does. The existence of the A350XWB will require Boeing to become more price-conscious on 777 RFPs to win business even if the 777 improves just as Airbus has needed to become more price-conscious on the A330 in the face of the 787 as their service dates start to converge.

But new airplane programs are expensive. Even "just" a re-engine and re-wing program can be very expensive - just ask Airbus with the A340-500/A340-600 and Boeing with the 747-8.

Airbus spent eleven-figures worth of Euros on the A380 program the past decade. They're preparing to spend another eleven-figures worth on the A350XWB program the next decade. And they're trying to renegotiate the A400M contract because that needs at least 10 figures more worth of Euros to put right. Finding another 9 to 10 figures worth of Euros to slap new engines and maybe a new wing on the A330 could be difficult, especially with reduced revenues from lower commercial deliveries.

Of course, Boeing is facing their own financial constraints, as well. The 787 program is closing on 11 figures worth of dollars and the 747-8 program is well into 10 figures. And a number of Boeing Military contracts are being reduced or eliminated so in addition to lower commercial revenues, Boeing will also have lower military and space revenues. So a full-blown 777 replacement program just may not be financially possible and even a major 777 update could put the squeeze on the guys down in Accounting.



Quoting Osiris30 (Reply 39):
I think you guys all really need to listen to the IAG podcast with the VP of the GTF from PW very carefully and then re-read this thread. (It was posted in the last week or two and Jon (Flightblogger) tweet'ed a link to it).

That was some pretty compelling information.  yes 

[Edited 2009-05-14 20:31:52]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-14 21:20:15 and read 27616 times.



Quoting Ikramerica (Reply 26):
Where is Boeing saying a warmed over 777 can outperform the A350?

"in the best case scenario [for the A350]", Boeing could "come to market within three to four years with a 777-replacement aircraft that is overwhelmingly superior to the A350".
- Kostya Zolotusky, managing director of capital markets development at Boeing

Not only outperform, be "overwhelmingly superior". Personally, I think he's nuts, but that's just me. The A350XWB targets are incredibly aggressive...I really hope Airbus meets them, but I have no idea how they're going to do it with the technology they've said they're putting in play. For Boeing to say they can drastically beat the A350, which is already drastically beating the 777 if Airbus can delivery, is basically saying that Boeing already has something which can trounce the 787...and I'm not sure how that's possible.

Quoting JoeCanuck (Reply 30):
I believe the 777 was designed using computational fluid dynamics. I was wondering more how much fluid dynamics have improved since the 777...if any.

CFD goes way back, at least to the 757/767 in commercial use that I know of, and probably farther than that. It's been getting better all the time. The primary advances have been better meshing systems and faster computers (so the cost of a simulation comes down). Today's solvers are pretty robust, the trick is all in how you set up the problem.

Quoting CARST (Reply 31):
Anyone know if it is possible to convert a steel-design into an CFRP-design?

You can, but it doesn't work all that well because you lose a lot of the benefits of CFRP when you do that.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ken777
Posted 2009-05-14 21:28:51 and read 27543 times.

What would be interesting to know is what Boeing was working on before the problems of the 787 pulled engineers off various projects.

I can remember that a few years ago Boeing called the 787 development a "Y1/787 Development Program". I can also remember that the engines for Y1 were not due until 2015 - which is getting closer every day.

If Boeing was moving towards a Y1 program to keep good customers like WN happy then how close are they to moving forward with it - and how much delay have they been hit with because of the 787 delays?

What would Boeing have now? We know they have learned some lessons on "partners" and would know which ones (like Spirit) could be relied on.

We know that they had a joint R&D program with the 787. I would guess that, if there was financing from the better partners, Boeing could move fairly quickly. It would seem logical that Boeing wold be talking to various partners and larger 737 customers before the 787 takes to the air. You know that WN chats with them every now and then.

Considering the availability of engines in 2015 and the EIS of the 787 in 2010, what are the chances of Boeing going for Y1 while tweaking the 777. Then when funds are flowing in on the 787 program move onto Y3?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-14 23:25:46 and read 26778 times.

The issues is last I checked the 777 has payload advantages over the 350. If you HAVE to have the payload/range of a 777LR the A350 just doesn't get it done. Sure you pay for it, but its going to make airlines using that capacity think twice before ordering A350 instead of waiting for the next thing.

A 777 replacement at this point I think HAS to be 11Y with 17.2 seats. Going 10Y at 17.2 is hardly different than the 787 in capacity, and limits your growth of that plane going down the road. People complain about "wasted volume" but the frontal area and surface area growth isn't that bad... and that volume can be used for equipment, crew rests, storage, etc. Be interesting if they could use the 10ft cans from 777/747 main deck ops packed for sideways placement on the lowerdeck of this plane to also make use of the larger diamiter fuselage. More to the point carbon will start allowing more interesting shapes to be used with lower weight penalties.

Timeframe? I DON'T see 4 years from now as a possiblity.... UNLESS they can recycle alot of 787 components. IE "copy => paste" the wings with the wingspan growth entirely as a "wing root plug" but fully integrated. So the R&D would mostly be the new flap section and structure between the old wing and the new wing box. Re-use most of the equipment as is when you can. Need more AC capacity? use 50% more units but identical units. Try to use the same APU. etc. Attempt to as much as possile use as much of the 787 section 41 like the 777 used as much as possible the 767 section 41, only in this case more of the reverse. outer structure optimized for the new plane, internals as close to the same as possible. This might also be where they make the REAL killer of the A350. If both planes use 50%+ of the same parts, the economies of scale will not only make this new mega 777 replacement far cheaper than it would be otherwise, but the price of 787 production will ALSO drop.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: BrightCedars
Posted 2009-05-15 01:04:39 and read 26148 times.

I always said there would be something like a 777-8 and a 777-9 and that's what will happen.

These birds will be very nice and will provide outstanding competition to Airbus' family of A350s and as today one will be more suited for some missions and one for others, small and medium airlines will have to choose either on criteria that matter to them while larger airlines will have to pleasure to get both and max out their respective potentials.

Not a second I doubt Boeing will deliver on the 787. It may take longer to get there but it will be an outstanding product that will evolutionize the way planes are built forward.

The 747 seems to be near the end of it's manufacturing life and the A380 sure will be taking the relay for many years to come and grow in performance and glory.

I'm eagerly waiting for the next battle and to see what the brains at Airbus and Boeing will come up with to revolutionize short and medium haul travel and replace the A320 and B737.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-15 01:12:09 and read 26260 times.



Quoting XT6Wagon (Reply 43):
Try to use the same APU. etc. Attempt to as much as possile use as much of the 787 section 41 like the 777 used as much as possible the 767 section 41, only in this case more of the reverse. outer structure optimized for the new plane, internals as close to the same as possible.

Well on said Ecoliner we (Henry Lam) used the 787 nose. I remain convinced >10 abreast means a double deck becomes a good idea. ) The 777 e.g. already has a waterhead and the A380 a moderately effective cargo bay.



Boeing looked at 12 abreast in the nineties. Its just hard to fill a very wide cross section in a way the airlines like (revenue generating seats & containers.



Quoting XT6Wagon (Reply 43):
This might also be where they make the REAL killer of the A350.

I think we have to wait a bit before the 777 killer flies in a few yrs before we can see were the A350 killer will go.. I have the feeling the recent comments by Boeing have more to do with the B747-8i failing to attract customers & Boeing loosing grip on on the VLA segment then matching the A350.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-15 01:28:46 and read 25990 times.



Quoting Tdscanuck (Reply 41):
"in the best case scenario [for the A350]", Boeing could "come to market within three to four years with a 777-replacement aircraft that is overwhelmingly superior to the A350".
- Kostya Zolotusky, managing director of capital markets development at Boeing

So apparently you can't read?

A 777 REPLACEMENT is not a WARMED OVER 777. That's like saying the A350 is a warmed over A330, or the 787 is a warmed over 767.

What is so hard to understand? They are talking about two DIFFERENT things.

1. They would upgrade the 777 if the A350 isn't looking like it will live up to claims, and would hope to have a plane that is "competitive" to an underperforming A350.
2. If A350 really performs, they can have a 777 REPLACEMENT within 4 years of deciding to launch it (because they've been working on this Y3 concept internally for years).

Basically, they will know pretty well by 2012 what the story is. The A350 is sold out through 2015-16 anyway, and the A350-1000 isn't arriving until 2015. That means a 777 replacement could be available for delivery in 2016 or 2017, right about when there is availability for the A350 product line.

In other words, because of the popularity of the A350 and 787, all those lines are full enough that, just like the A330 with Airbus, if operators want aircraft before 2015, it's the 777 in that class or nothing. And they can have a new model by 2016 without having to decide for a few years.

She's just reiterating the timeline that I've been pointing out for years.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AFKL
Posted 2009-05-15 02:20:16 and read 25538 times.



Quoting Ikramerica (Reply 46):
A 777 REPLACEMENT is not a WARMED OVER 777. That's like saying the A350 is a warmed over A330, or the 787 is a warmed over 767.

I disagree. If it is, as you say, a completely new design, (just like, in your words, the A350 is for the A330), it will take Boeing a whole lot longer than four years to get a T7 replacement. In the end, it will be, and must be based on the current T7, to be able to come up with something competitive in the span of four(!) years. In the article all that is mentioned is new wings and engines, which in my book is classified as a warmed over design, in a similar way the 747 has been warmed over with each new version. Even the 747-8i is facing troubles meeting time targets (with several minor delays already), which is also based on an existing design (though these delays could be blamed on the delays of the 787).

The key strength for Boeing, in this case, is being able to come up with a competitive design in a short time-span, with relative lower investment costs, compared to the A350. I am sure they will be able to do so, yet I'm just skeptical with their use of "overwhelmingly superior".


ALLARD.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Par13del
Posted 2009-05-15 04:28:16 and read 24671 times.



Quoting AFKL (Reply 47):
In the end, it will be, and must be based on the current T7, to be able to come up with something competitive in the span of four(!) years.

What exactly is the T7, an a/c in the 300+ pax range, it was designed years ago and improvements have been made to it over a decade or so.
Boeing has done initial studies on new a/c, speculation on this site has called them YXX etc., if one of them is / was a look at the 300+ pax market, it is much longer than 4 years. I do not take the 4 year time frame to be from initial thoughts, design, production then delivery, I take the 4 years to be offer for sale to delivery, if no one bites, do you expect a delivery in 4 years, delivery will depend on purchase.

There are no new a/c shapes, the twin deck A380 was not new, it was studied before no one thought there was a case so it was not built. Wing design has changed / improved by how much, we are mostly seeing tweaks in the less than 10% improvement range, engines improvements even if radical design changes essentially fall in the same category of improvement, the 10-20% improvement mentioned for any new frame over its predecessor has to be a combination of all major components, there is no new magic bullet coming along, at least not right now.

IMHO what we have today is economics, bean counters, any a/c presently in service can be justified by "fudging" the numbers, for example, folks like to say that the A330 killed the B767, a large number of them are still in service making a profit for their owner, if the current A330 model was offered for sale at the same start date of the B767 the market would be different, but the B767 improved model -300 had the market to itself for years, hence the large number still in service. The B777 has a similar case, the A340 was supposed to be competiton to the B747.

The initial A350 attacks the B777 from below, that means that there is no attempt to take away the range or payload advantage, it economic, in my simple terms rather than spending 2x to take 100 pax 2b miles, you can spend 1x to take 80 pax 1c miles and make the same profit, look thru all the RASM, CASM and other SM's and you get the idea of what I am talking about. Other than the A380 lifting more and travelling further than its predecessor - B747 / A340 - the rest are compromises of economics, including the B787 with the B767 and A330. One now has to be an economist to say my a/c is better than yours, of course for us fans, looks are in the eyes of the beholder and thats where the competiton comes to a head  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Nomadd22
Posted 2009-05-15 04:48:18 and read 24482 times.

"in the best case scenario [for the A350]", Boeing could "come to market within three to four years with a 777-replacement aircraft that is overwhelmingly superior to the A350".
- Kostya Zolotusky, managing director of capital markets development at Boeing

I wouldn't get too worked up over marketing semantics. a 5% advantage in operating costs would be considered "Overwhelming" by a lot of folks, and they'd have a point.
I read it as a replacement for the 777. I think there might be a misunderstanding over the term "offer". That wouldn't be four years to EIS. Just four years till it was offered. Hence the term, "offer".

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: CARST
Posted 2009-05-15 04:52:39 and read 24437 times.



Quoting AFKL (Reply 47):
disagree. If it is, as you say, a completely new design, (just like, in your words, the A350 is for the A330), it will take Boeing a whole lot longer than four years to get a T7 replacement. In the end, it will be, and must be based on the current T7, to be able to come up with something competitive in the span of four(!) years.

 checkmark 

I have to agree on this part of your comment...

Four years is such a short time-frame, that i can only think of a warmed-up 777. But like i said earlier in this thread, i think of that in a positive way.

Just take the 777 design, make the aircraft out of CFRP to save weight and fuel, put new improved GE90s or GTFs on the bird and offer two models, one in in the 300ER range and one in the 748i range.
Let the 200ER/LR range open for the 787-10, this way they could optimise the wing for the new greater model, too.

(People might argue now the 787 might need a new wing, too, to offer a -10 model, but this might be a good idea anyway. One large wing for 10, 9ER, 8ER and one small wing for the normal 8 and 3 to have an A300 replacement.)

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Astuteman
Posted 2009-05-15 04:59:30 and read 24391 times.



Quoting Ruscoe (Reply 19):
What this boils down to is whether the panel design of the 350 is as good as the wound fuselage of the 787.

My own view on that is that the difference that this might make when expressed in terms of overall aircraft performance, and cost of ownership/operation, will be completely trivial.

Just my  twocents 

Rgds

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: 757GB
Posted 2009-05-15 05:35:47 and read 24071 times.



Quoting Par13del (Reply 48):

 checkmark 

What I wanted to say was pretty much in line with your post.
I read the article and frankly to me it means nothing more than the regular war of words between A & B, the same thing that happened regarding the 787/A350 V1-5.

Don't get me wrong, I love the discussions and learn a lot from them. But IMHO I don't think anybody can really say with that level of confidence how it will go (from both sides).

There is a lot be be SEEN about the 787 beyond what has been SAID.
The same goes for the A350: much has been SAID but it will be a while.
There is however a lot that has already been SEEN of the 777. I'm not going to call anything a "777 - killer" just yet. There is still a lot that remains to be seen...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AFKL
Posted 2009-05-15 05:38:54 and read 24041 times.



Quoting Nomadd22 (Reply 49):
I read it as a replacement for the 777. I think there might be a misunderstanding over the term "offer". That wouldn't be four years to EIS. Just four years till it was offered. Hence the term, "offer".

Then where would Boeing's advantage be?


ALLARD.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Jfk777
Posted 2009-05-15 05:47:05 and read 23994 times.



Quoting AirbusA6 (Reply 11):
The 787 didn't kill the A330, which has sold in record number over the last few years.

The A330's recent success has been more because the A340 are such gas guzzlers and increased range of the A330-300 operated on long routes like Finnair to Asia.

Quoting CARST (Reply 15):
If B is planing to make a complete new 777 it could be a huge success, it remains the question would it be profitable?

I imagine something like the step from 742/743 to 744. A complete new 777, build from CFRP, and some 787 technology integrated

IF the 777-300ER were "OLD" then BA, Cathay, Singapore & ANA would order it.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: CARST
Posted 2009-05-15 05:54:53 and read 23890 times.



Quoting Jfk777 (Reply 54):
IF the 777-300ER were "OLD" then BA, Cathay, Singapore & ANA would order it.

With my comparison from a jump from 742/3 to 744 i didn't want to say the 777 is a old product, it is with all its evolutions a quite new one, but if you bring the A350 into the picture and think of the year 2013 it might be good for Boeing to offer an improved CFRP-777 in the 2013-2016 time-frame to have the upper hand again in the 300seat+ market.

And to have the upper hand they would to revolutionize the 777 (perhaps with CFRP) and thus is why i was referring to the jump from 742/743 to 744.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Parapente
Posted 2009-05-15 06:45:35 and read 23476 times.

I believe (for Boeing) the root of the problem lies with their change of strategy.The origonal Y1 -Y3 was perfect (IMHO).Whether Y3 was an Ecoliner or a BWB is neither here or there.But they made a (cost) decision to spend their money on a warmed over 747. Did it work? Too early to say. They have kept the Freighter market for sure and no doubt lowered the sales margin on all 380's.But I do not think they spotted the late change of market positioning of the 350.Frankly quite a clever move by Airbus.

Both companies have to build new Y1's next thats certain. Neither has the capital resources to do so at present (that's also certain) so we see them both pushing it to the "right". There will not and cannot be an all new 777 now - there is not the money.

We already know (as they published it) what the 777-200 replacement was going to be.The 787-10. It still may be.If they can get the weight down enough.

The real issue I feel is whether the 77W can compete with the 350-1000.I believe it will.Perhaps a very small stretch,a tweek of wings a little weight reduction and some engine performance tweeks. Do they plan this?Well we have heared 3 major CEO's ask for it publically. So my guess is yes.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-15 06:57:09 and read 23395 times.

Quoting Stitch (Reply 4):
Airbus did not offer a chart on 350+ seat (777-300ER / A340-600) replacements. However, at 20 year lives, that means the ~184 77Ws already delivered will not need replacement with an A350-1000XWB until the 2024-2029 timeframe and 219 more will not need replacement until at least 2029.

Very good point. The A351 entered the market when the market was saturated by the newest and most efficient wide-body at the time, the 773ER. Again a clear case when market saturation is the main factor when judging the A351 sales.

Quoting Stitch (Reply 4):
I'm skeptical on Airbus' claims that the A350-1000XWB will have 25% lower block fuel and cash operating costs per seat then the 777-300ER. I also am skeptical of Airbus' comparison between the A350-900XWB and the 777-200ER. And the 777-200LR is said to have lower block fuel and cash operating costs then the 777-200ER.

But even if the A350 misses the targets significantly the efficiency advantage will be larger than between 787 and A330.

Quoting Ruscoe (Reply 19):
Why? Because apart from anything to do with weight , shape or fatigue, a major attraction of the design and manufacture of the 787 fuselage, is that it can be scaled, without major redesign.
When this method of manufacture was first mooted, Boeing was saying this and I have not heard anything different.

On the other hand the large panel design of the 350, built up on an aluminium stripped CFRP frame, is not easily scaled, without a major redesign..

Both Airbus and Boeing claim publicly the superiority of their approach. Airbus calls full barrels old fashioned. In this thread I discussed possible reasons:
http://www.airliners.net/aviation-forums/tech_ops/read.main/216974/

My boldest forecast ("The B787 will be the last airliner using CFRP barrel fuselages") has been proved true until now:
- The next CFRP fuselage project (b.t.w. from the US) uses fuselage shells:
http://www.aviationweek.com/aw/blogs...918845-aaa6-42f3-adb8-895b2b26d513
The technology without autoclaves is also ready to be used for the A350 fuselage production. All indications are that this will be the way for the future.

Quoting Ruscoe (Reply 19):
In practical terms it is probably more thruthfull than arrogant of Boeing to say, that if necessary, they could produce a replacement 777 within a few years. It would be a scaled 787.

I have said other times:
The 787 is a bad object to scale up. Even the things like the cross section that normally are predestined are no good candidates (Airbus made 4 aicraft types and 11 subtypes from the A300 cross section). Why?
- The 8.5 abreast cross section is suboptimal to grow really into the 350-400 seater area.
- I have the feeling that the 787 fuselage technology will sooner be outdated than we would think now. For me the 787 shows many clear V1 qualities. Future CFRP planes could make the 787 obsolete from the technological standpoint within 10..20 years.
- Beside the technology there is the less-than-ideal production setup. Boeing will suffer from some decisions in that area for the whole time of 787 production. If I would be Boeing I would not want to use that part of the 787 programme as cornerstone for anything new.

Quoting Ikramerica (Reply 26):
Quoting Acheron (Reply 13):
Now comes Boeing saying that a warmed over 777 can outperform the A350, and people go saying is entirely possible.

Where is Boeing saying a warmed over 777 can outperform the A350?

You speak of Boeing but he meant people (e.g. on this forum).

Another important point is the workload:
This discussion just fades out the rest of the product portfolio. When discussing the narrowbodies we all dream of 737/A320 successors. Those programs overlap with the T7 replacement. Here I see a clear advantage for Airbus:

Either the A350 or the A320 successor will take away market from Boeing excessively. Simply because Boeing WILL not be able to build a competitive answer to both.

If Boeing is bound to make a T7 replacement after 2015 Airbus has all the time in the world to create a single-vendor market for narrowbodies.

After the A350 is finished (and the 781, 748) Boeing has two clean sheet programs on the table (Y1 and Y3) and Airbus one (A320 successor). IMO an overwhelming advantage for Airbus.

Edited to add:
B.t.w the ACCA plane from the link above is a real world example how an ex metal plane can be reconstructed to get large new CFRP parts. The 777 could benefit from such an approach too.

[Edited 2009-05-15 07:06:02]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-15 07:05:57 and read 23262 times.



Quoting Rheinwaldner (Reply 57):
My boldest forecast ("The B787 will be the last airliner using CFRP barrel fuselages") has been proved true until now:
- The next CFRP fuselage project (b.t.w. from the US) uses fuselage shells:
http://www.aviationweek.com/aw/blogs...918845-aaa6-42f3-adb8-895b2b26d513
The technology without autoclaves is also ready to be used for the A350 fuselage production. All indications are that this will be the way for the future

A very interesting post Rheinwaldner. Boeing marketing will probably see things a bit different, but from what I can read about the subject (and the tests being done by other composite manufacturers) your conclusion might be spot-on.  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-15 07:12:17 and read 23215 times.

We know Y3 exists, at least as a series of design studies. What we don't know is how far those design studies have advanced.

I would not be surprised that as the 787 moved into development and now production, that data is being fed back into the Y3 design study group. So for all we know, Boeing really does have a CFRP 777 replacement in at least a somewhat advanced state of design which would mean that should they decide to pull the trigger on launching it, they will already be done part of the way.

We also need to remember the original A350 had a projected EIS within four years of the formal industrial launch in late 2005. True, this plane used Al-Li instead of CFRP, but it still incorporated a number of changes from the original "A330 Mk. II".

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Brendows
Posted 2009-05-15 08:06:10 and read 22739 times.



Quoting Rheinwaldner (Reply 57):
All indications are that this will be the way for the future.

It's way too early to say that for certain, there are three different approaches and each one are a first of its kind. If the next few major airliner programs uses the same approach as one of these three candidates I'll agree with you.

Quoting Rheinwaldner (Reply 57):
The 787 is a bad object to scale up.

Not really, but every design has its limits.

Quoting Rheinwaldner (Reply 57):
- The 8.5 abreast cross section is suboptimal to grow really into the 350-400 seater area.

Definitively, Boeing didn't want to push the design into T7 size for obvious reasons. That may end up being a bad move. And we must also remember that the 787 was advertised as an eight abreast airliner in the beginning, so was it Boeing that "discovered" the possibility to seat nine abreast, or was it some potential customers?

Quoting Rheinwaldner (Reply 57):
- I have the feeling that the 787 fuselage technology will sooner be outdated than we would think now. For me the 787 shows many clear V1 qualities. Future CFRP planes could make the 787 obsolete from the technological standpoint within 10..20 years.

Maybe, maybe not, it's too early to tell.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-15 08:19:01 and read 22637 times.



Quoting Rheinwaldner (Reply 57):
But even if the A350 misses the targets significantly the efficiency advantage will be larger than between 787 and A330.

Maybe... Maybe not...

Depending on how you interpret Boeing's original 7E7/787 claims, you could argue Boeing was stating 787 block fuel and operating costs would be upwards of 20% better then the A330-200.

The A330-200 and Trent 700 have only gotten better the past four years, so however good the 787 turns out to be this year, the difference won't be as great as it would have been four years ago.

I expect the 777-200LR/777-300ER and the GE90-11xB also will only get better over the next four to six years, so however good the A350-900XWB/A350-1000XWB turn out to be when they respectively enter service, the difference won't be as great as it would have been in June 2007.

I fully expect the 787 to be better then the A330 and I fully expect the A350XWB to be better then the 777. But I believe that both Airbus and Boeing were overly optimistic in their initial projections on just how much they would be better.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Cosmofly
Posted 2009-05-15 08:25:54 and read 22560 times.



Quoting Keesje (Reply 45):



In the diagram, the ceiling of the ecoliner is lower than others.

I think Boeing's best and last bet to maximize 748i is to double the size of the overhead bins on both sides, eliminate the center bins and lower the ceiling to increase overhead floor space to put seats on.

There may be some strengthen of structures and challenges for new doors. However it can still be the cheapest and quickest way to keep A388 in check.

Boeing cannot compete on seats and range at the same time and I believe more seats at a lower acquisition cost, lower operating cost and higher residual cargo conversion value can be attractive to many carriers when economy picks up again.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: LH526
Posted 2009-05-15 08:33:23 and read 22496 times.



Quoting AFKL (Thread starter):
Boeing could "come to market within three to four years with a 777-replacement aircraft that is overwhelmingly superior to the A350".

hell, the 787 isn't even flying, the B748 hasn't even seen the final stages of production, and yet they are talking about a totally new plan that could "come to market within 3 to 4 years" .. gimme a break Boeing!

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-15 10:07:41 and read 21673 times.



Quoting LH526 (Reply 63):
hell, the 787 isn't even flying, the B748 hasn't even seen the final stages of production, and yet they are talking about a totally new plan that could "come to market within 3 to 4 years" .. gimme a break Boeing!

To be fair they have done aircraft programs in less than 4 years from board approval to start to EIS.

Like I said, right now I don't see it if you count 4 years from today.
4 years from 789 EIS? much more possible
4 years from 788 EIS with lots of "borrowed" 787 parts... Very possible.
4 years from 789 EIS with lots of "borrowed" 787 parts... Sure. Don't see why not.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinbote
Posted 2009-05-15 10:15:42 and read 21629 times.

Jeeez,

Headline:
"Boeing could offer all-new 777 replacement to rival A350 within four years"

Body of article:
"Boeing says that it could respond to any threat...before the end of the next decade."

In other words Boeing is talking about 4 years after A350 EIS, but certainly not four years from now. Nothing to write home to your mom about.

So where's the news?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Pnwtraveler
Posted 2009-05-15 11:30:19 and read 21350 times.



Quoting Stitch (Reply 59):
We know Y3 exists, at least as a series of design studies. What we don't know is how far those design studies have advanced.

And above someone asked what Boeing engineers are working on.

We know Boeing flew a Sonic Cruiser looking model not to long ago and other studies continue to be done. Maybe not front burner but some work is still being done. Whether there is a military or commercial application is not known.

We also know blended wing is also still being worked on. Not sure again if it is for another military application or commercial.

We also know supersonic is still being looked at.

The 748i is getting closer to design freeze which will free up engineers.

789 is well underway but will need a big push once the 788 is in the air and its data starts coming in.

According to a relative who worked on a lot of the 748i and before that 747-500/600, the Y3 is a long way along but is waiting again for real life data back from the 788 once it is in the air.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Osiris30
Posted 2009-05-15 12:10:45 and read 21250 times.



Quoting LH526 (Reply 63):
hell, the 787 isn't even flying, the B748 hasn't even seen the final stages of production, and yet they are talking about a totally new plan that could "come to market within 3 to 4 years" .. gimme a break Boeing!

3 to 4 years of the 350 coming to market. Give me a break indeed.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AirNZ
Posted 2009-05-15 14:49:19 and read 21028 times.



Quoting RedFlyer (Reply 2):
Your assumptions, and that of Mr. Shankland's of Airbus, assume the A350 suffers no delays and meets or exceeds its performance specs out of the gate. Possible, but not highly probable.

Yes, it's a valid enough point, but not one that his highly improbable either despite a lot of wishes on a.net (not meaning yourself at all). It must be appreciated that, while certainly possible, the disaster befallen the 787 programme in delays etc. does not automatically portray the same events for the A350. I feel this 'automatic' belief is too often overlooked/played upon here.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-15 15:19:01 and read 20987 times.

I'd like to comment on this one.

Boeing needs to come up with a Y3.
Since the A350XWB has been launched, only very few passenger B777 's were ordered for post-2013.

Boeing has to use their great know-how to come with something good.
By something good I don't mean a carbon all-electric Spruce Goose.

Boeing's success throught the last half century was founded on their ability to provide slight improvements leading to huge results. If you stand still and think about it, the evolution from B707 to the B777 was a progressive evolution parallel with the evolution of available proven technology.

What the Concorde proved is that super-evolutionary military-derived technology, though impressive and very entertaining, does not always provide commercial viability.
The B787 will in my opinion be another such aircraft and I expect that maintenance on the CFRP fuselage alone will be a huge mess, from repairing scratches/deformation caused by FOD to pressurization related question marks. It's the first pressurized aircraft with a CFRP fuselage, and while CFRP has shown to be very reliable in other primary structures such as wing spars and box, the tailplane, we don't know how it's going to behave as an aircraft skin... which has to absorb totally different patterns of forces.

Which is probably why Airbus went for CFRP panels rather than a single structure.

A B777RS, alright, but with CFRP panels, very advanced engines (open rotor?), Ti-alloy landing gear, a B787 cockpit (at least that one they got right) and evolutionary variable-geometry wing that could largely improve performance characteristics to suit a larger range of speeds better and more efficiently than flap/slats and steady wing sweep/span.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Nomadd22
Posted 2009-05-15 15:32:12 and read 20953 times.

Once again the fantasy that replaceable panels are going to be any kind of factor in maintenance, the idea that they have no knowledge of how a CFRP barrel fuselage will react and the notion that, for some reason CFRP will be subject to hard to repair damage. (First time I ever heard scratches)
Might as well have a CaptainX fanclub reunion.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-15 15:50:42 and read 20946 times.

If people really think airlines are going to be removing CFRP panels that could measure 20m (or more) in length to repair damage on the A350XWB, well...

I still believe CFRP will be more resistant to "ramp-rash" then Al, and there is plenty of reports about how Boeing plans to deal with it on the 787 on the web. I've read it and I feel confident.

As to pressurization, I would think something composed of multiple panels with seams between a dozen and a score meters would be harder to keep pressurized compared to a single structure that doesn't have those seams.


I believe Airbus went with panels because it required the minimum time to get to work, not because it's a superior idea. I guess we'll know in five years when the A350-800XWB and the 787-9 go head-to-head.


Bob Sala, Pratt's VP of Next Generation Product Family spoke about Open Rotors and while I admit he's not the most impartial of sources (since he's pushing GTFs), I believe his claims that Open Rotor engines will require significant mounting and noise insulation structure which will cut deeply into their projected 10% fuel burn advantage over a direct-drive engine. Also, he claims an Open Rotor engine needs almost twice the clearance of an engine in a nacelle which means you can't hang it under the wing and a 777 with engines on the tail would be...scary.  Wink

Depending on if Pratt could get one into service quick enough, a GTF for the 777 might very well be amazing. Sala said that as the fan gets larger (133-138" for 100k pounds of thrust) the engine gets shorter compared to conventional engines because they can remove engine stages along with their attendant discs and airfoils. This also makes the engine lighter and reduces maintenance (less parts). And the bigger the engine, the better the SFC gains. And they can position it closer to the wing's leading edge which evidently helps with the aerodynamics and reduces the amount of wing structure necessary to support the engine.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Cerecl
Posted 2009-05-15 17:41:17 and read 20779 times.

I am lost as to why so many people enthusiaticsally believe that Boeing/Airbus can completely trump its competitors product with a "overwhemlingly superior" offer within the space of 4 years.
A333 EISed in 1993, A332 EISed in 1998, 10-15 years later Boeing is still trying to get 787-8 in the air and A330 series is doing well. 777 EISed in 1995, 77W in 2004, Airbus will not have an answer until 2013-2015, another 10-18 years. Unless one believes that either A or B is miles ahead in aircraft design, what prevented them from launching the A320RS or 737NNG will also prevent them from trumping each other's product.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-15 18:32:43 and read 20715 times.



Quoting Stitch (Reply 71):

If people really think airlines are going to be removing CFRP panels that could measure 20m (or more) in length to repair damage on the A350XWB, well...

I suspect in the end, if Boeing develops the tools for it, replacing a whole barrel would be quicker than replacing a panel since they are assembling a whole barrel at a time with quick connects at the joins. I suspect the panel approch will require alot of peeling of wiring, plumbing, and other bits for a HUGE section of the plane. Cost? Well, Time is money, so the cost of buying a whole new barrel section pre-stuffed to get a plane back in service might end up cheaper than all the hand work of stripping 60ft of plane then disassembling the skin, put in new skin, then reassemble all that stuff. Comparable requirements to "iron maiden" the plane so you don't break stuff as you undo the stucture.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-15 21:34:51 and read 20536 times.

If it's anything like repairing other composite structures, they will probably just repair the bits that are broken. The panel joints will probably be bonded and fastened to the frame making it virtually impossible to separate the panel from the frame. The adhesives will likely be stronger than the panels themselves.

Major repairs will probably involve cutting out the damaged piece and patching. They can overlap and feather the edges back and blend the patch right in. That's for an external patch. If they want it flush, they might have to get at it from the inside.

Composite patching really isn't that big of a deal...it's been going on for decades.

[Edited 2009-05-15 21:51:53]

[Edited 2009-05-15 21:52:46]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: 757GB
Posted 2009-05-16 05:29:00 and read 20216 times.



Quoting NCB (Reply 69):
evolutionary variable-geometry wing that could largely improve performance characteristics to suit a larger range of speeds better and more efficiently than flap/slats and steady wing sweep/span

I'm not sure what specific system you're thinking of. What comes to mind for me is swing wing. I'm no engineer, but I understand that the swing wing has a weight penalty to it, as you have to carry around the mechanism required for it to function. Is this what you're referring to?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Panais
Posted 2009-05-17 10:02:05 and read 19803 times.



Quoting Keesje (Reply 45):
Well on said Ecoliner we (Henry Lam) used the 787 nose. I remain convinced >10 abreast means a double deck becomes a good idea. ) The 777 e.g. already has a waterhead and the A380 a moderately effective cargo bay.

Why not based the Ecoliner on an 8 abreast (lower section) and 5 abreast (higher section)?

Make it slightly wider than the A330 to make it more comfortable. The 8 abreast becomes more versatile when building a first class cabin with 1+2+1. Additionally, the 5 abreast configuration above is excellent for a 2+2 business class layout.

Cargo-wise, it will take the same sized containers as the 777.

Boeing can start with a 400 3-class configuration layout and then shrink to 350 seats and extent to 460 seats.

This way they cover the 777-300, the 747-8 and the A380 with a single investment.

If they simply replace the 777-300, then they have a single product, to compete against a family, the A350.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-17 12:12:11 and read 19672 times.



Quoting Cerecl (Reply 72):
I am lost as to why so many people enthusiaticsally believe that Boeing/Airbus can completely trump its competitors product with a "overwhemlingly superior" offer within the space of 4 years.

Maybe they see a flaw in the A350 design that they feel they can exploit? I don't know. I think "overwhelmingly superior" is a tall order. The last aircraft to achieve that was the 77W, which killed the market for a relatively brand new model in the A346. The 787 hasn't been able to do that to the A330.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-18 01:37:22 and read 19304 times.



Quoting Brendows (Reply 60):
Quoting Rheinwaldner (Reply 57):
All indications are that this will be the way for the future.

It's way too early to say that for certain, there are three different approaches and each one are a first of its kind. If the next few major airliner programs uses the same approach as one of these three candidates I'll agree with you.

My point here was autoclave-free production. You won't find sources which state the use of autoclave being as future-proof. If possible you avoid them. You are aware that the A350 fuselage IS made without autoclaves? If it only reduces the production cost it brings huge advantages and qualifies alone to call the full barrel autoclaves "old fashioned".

Quoting Brendows (Reply 60):
Quoting Rheinwaldner (Reply 57):
- I have the feeling that the 787 fuselage technology will sooner be outdated than we would think now. For me the 787 shows many clear V1 qualities. Future CFRP planes could make the 787 obsolete from the technological standpoint within 10..20 years.

Maybe, maybe not, it's too early to tell.

There are documents in the internet that show clearly that CFRP is not just CFRP. 2nd Generation CFRP will be much better regarding weight and cost than the current materials and methods.

Quoting JoeCanuck (Reply 74):
The panel joints will probably be bonded and fastened to the frame making it virtually impossible to separate the panel from the frame. The adhesives will likely be stronger than the panels themselves.

That would not be wise. IMO it will be fastened.

Quoting JoeCanuck (Reply 74):
They can overlap and feather the edges back and blend the patch right in. That's for an external patch. If they want it flush, they might have to get at it from the inside.

I don't agree. The problem with the 787 skin is IMO if the damage cracks the surface and destroys the underlying stringers. The patch that needs to be made suddenly is very complex. For each patch an outside-mandrel has to be created and somehow inner structure has to be reconstructed. Each such case will be costly.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Autothrust
Posted 2009-05-18 03:50:41 and read 19123 times.



Quoting Ikramerica (Reply 77):
I think "overwhelmingly superior" is a tall order.The last aircraft to achieve that was the 77W, which killed the market for a relatively brand new model in the A346

Wait a minute.  redflag 
The success of the 777 was not attributed from its superior technology, its obvious you will burn less with big two engines then four.

Make a A330 as big as the 773 hang on it some GE 115 and it would easily beat the A346. The penalty's a quad design brings on the table made the 777 look more attractive.. The credits go to GE for the fantastic engine. The A346 is incredibly sophisticated i would really be careful to claim otherwise.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: StickShaker
Posted 2009-05-18 05:10:00 and read 18989 times.



Quoting Rheinwaldner (Reply 57):
Quoting Stitch (Reply 4):
Airbus did not offer a chart on 350+ seat (777-300ER / A340-600) replacements. However, at 20 year lives, that means the ~184 77Ws already delivered will not need replacement with an A350-1000XWB until the 2024-2029 timeframe and 219 more will not need replacement until at least 2029.

Very good point. The A351 entered the market when the market was saturated by the newest and most efficient wide-body at the time, the 773ER. Again a clear case when market saturation is the main factor when judging the A351 sales.

What about the 744 replacement market ? Should be quite a few that need to be rolled over around 2015 or so - wouldn't airlines be choosing between between the 77W and 350-1000 assuming the 380 is not suitable.

Regards,
StickShaker

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AirbusA6
Posted 2009-05-18 05:56:08 and read 18921 times.



Quoting Autothrust (Reply 79):
Make a A330 as big as the 773 hang on it some GE 115 and it would easily beat the A346. The penalty's a quad design brings on the table made the 777 look more attractive.. The credits go to GE for the fantastic engine. The A346 is incredibly sophisticated i would really be careful to claim otherwise.

The fuselage would still be an problem though, the A346's issues against the 77W aren't solely because it's a quad, doesn't it's extreme length when comparead to its diameter cause structural weakness issues?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-18 05:59:21 and read 18995 times.



Quoting JoeCanuck (Reply 74):
Major repairs will probably involve cutting out the damaged piece and patching. They can overlap and feather the edges back and blend the patch right in. That's for an external patch. If they want it flush, they might have to get at it from the inside.

Composite patching really isn't that big of a deal...it's been going on for decades.



Well damages happen al the time. I still wonder how fast a repair can be done if pieces of fuselageframes are laying on the platform. Those catering trucks are very heavy..

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-18 06:31:10 and read 18842 times.



Quoting Keesje (Reply 82):


Well damages happen al the time. I still wonder how fast a repair can be done if pieces of fuselageframes are laying on the platform. Those catering trucks are very heavy..

Such damages I meant. Is it acceptable to go for the ultimate solution in cases like this?

XT6Wagon made us believe even replacing whole barrels is feasile:

Quoting XT6Wagon (Reply 73):
if Boeing develops the tools for it, replacing a whole barrel would be quicker than replacing a panel since they are assembling a whole barrel at a time with quick connects at the joins

I say: if cases like the one on the picture above lead to full-barrel-replacement it is a catastrophe. If not the reconstruction of the patch + stringers alone can mean:
- Cutting away the material to get a proper area to patch (but: sawing CFRP is unwanted)
- Making the outside mandrel just for this area of the fuselage. Each patch needs new tooling.
- Build the new part, somehow reconstruct the stringers on the inner side.
- Somehow provide a proper fusion of the shell and the new inner parts with the original structure.

Both (full-barrel-replacement and patching) requires an enourmous effort.
I am convinced that replacing panels is easier. At least the plane remains in one piece. If you fix the plane with trestles it should be possible to replace quite large portions of the shell. The hydraulic and electric lines (+ air and water ducts....) can stay in place.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-18 09:33:38 and read 18547 times.



Quoting Rheinwaldner (Reply 78):
You are aware that the A350 fuselage IS made without autoclaves?

I searched but I couldn't find any EADS info about the 350 sections being cured outside an autoclave.

Quoting Rheinwaldner (Reply 78):

Quoting JoeCanuck (Reply 74):
The panel joints will probably be bonded and fastened to the frame making it virtually impossible to separate the panel from the frame. The adhesives will likely be stronger than the panels themselves.

That would not be wise. IMO it will be fastened.

Bonding makes for a much stronger join, which means less material. It would also provide a great seal.

Quoting Rheinwaldner (Reply 78):

Quoting JoeCanuck (Reply 74):
They can overlap and feather the edges back and blend the patch right in. That's for an external patch. If they want it flush, they might have to get at it from the inside.

I don't agree. The problem with the 787 skin is IMO if the damage cracks the surface and destroys the underlying stringers. The patch that needs to be made suddenly is very complex. For each patch an outside-mandrel has to be created and somehow inner structure has to be reconstructed. Each such case will be costly.

The 350 will also have internal stringers and ribbing. Their repair needs will be virtually identical.

Just because the fuse is autoclave cured doesn't mean that the repairs will be. The main benefit of an autoclave is that it can precisely control the curing time of very large pieces. Epoxy curing for smaller pieces can be just as strong.

Quoting Keesje (Reply 82):

Any repair that big wouldn't be accomplished on the ramp.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-18 11:49:30 and read 18365 times.



Quoting Rheinwaldner (Reply 78):
I don't agree. The problem with the 787 skin is IMO if the damage cracks the surface and destroys the underlying stringers. The patch that needs to be made suddenly is very complex. For each patch an outside-mandrel has to be created and somehow inner structure has to be reconstructed. Each such case will be costly.

Says who? Unless you know the technology of the 787 inside and out, it's speculation, and the most pessimistic speculation at that. Fine, but it's not fact. It's your opinion, so don't say "the problem is" as if that's established...

Quoting Autothrust (Reply 79):
Wait a minute.  

I didn't say why it did. It just did. You can't refute that the 77W killed the market for the A346. No evidence would support you.

And, last time I checked, 115k engines ARE new technology. So were some of the gear and tail strike prevention measures on the 77W that allowed for the MTOW it needs. So was the ETOPS technology needed to make it a viable alternative to a quad.

So, be upset that Boeing won that round all you want, but it's not a red flag. A346 is dead in the market, 77W is not. You make the call...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-18 12:07:55 and read 18303 times.

I for one like to think the airlines I patronize do not have incompetent boobs running their maintenance groups. So if they feel confident a 787 can be repaired, then I feel confident a 787 can be repaired because, well, they know more about it then I do.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-18 12:13:08 and read 18269 times.



Quoting Stitch (Reply 86):
I for one like to think the airlines I patronize do not have incompetent boobs running their maintenance groups.

Let's hope so.  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Jambrain
Posted 2009-05-18 12:25:06 and read 18247 times.



Quoting Autothrust (Reply 79):
its obvious you will burn less with big two engines then four

I don't know which law of physics says 2 are more economical then 4, if all key parameters are equal:-
i.e. pressure ratio, byepass ratio, turbine engine temperatures, turbomachinery effeciency

Due to engine out redundancy it can be easier to match a quad vs a twin. (a twin needs 100% more thrust in case 1 engine fails a quad just 33% more) this means a quad can have a cruise thrust at a higher % of takeoff thrust which is good for SFC.

Of course to have 4 engines with the same tech as a GE90-115 gives more money to the engine manufacturer.  Big grin

The one factor that does improve with scale is tip clearance effects but that isn't as dominant as some would have you think.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AutoThrust
Posted 2009-05-18 14:01:08 and read 18138 times.



Quoting Ikramerica (Reply 85):
You can't refute that the 77W killed the market for the A346

I don't, i just refute your comment making the 77W looking much more advanced then the A346.

Quoting Ikramerica (Reply 85):
115k engines ARE new technology

Never said they weren't.But the 777 frame is not. Maybe you re-read my post?

Quoting Ikramerica (Reply 85):
So were some of the gear and tail strike prevention measures on the 77W that allowed for the MTOW it needs

Nothing groundbraking.

Quoting Ikramerica (Reply 85):
So was the ETOPS technology needed to make it a viable alternative to a quad.

Agreed, but Boeing just extended that "technology" to longer periods.

Quoting Ikramerica (Reply 85):
So, be upset that Boeing won that round all you want

I'm neither upset about Boeing or that the 777 is a more efficient design, which is why it rightfull won.
Just people should try be honest and acknowlege atleast even the A346 was a economic failure its still an incredible advanced plane.

Btw i welcome the success of the 777 as Airbus was overconfident on the A346. And competition is always good.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ken777
Posted 2009-05-18 14:24:03 and read 18091 times.



Quoting Rheinwaldner (Reply 57):
After the A350 is finished (and the 781, 748) Boeing has two clean sheet programs on the table (Y1 and Y3) and Airbus one (A320 successor). IMO an overwhelming advantage for Airbus.

What about before then? The 788 is flying and the 789 is developing smoothly (one hopes) and the 748 is ready to fly or EIS. Boeing has the luxury of looking at various projects with Y1 & Y3 being the obvious projects.

Now, where are the partners (the ones who performed well) and what are they doing? I would guess that a few would be able to move on a new project - on either side of the 787. I don't know how financially strong Spirit is, but would be surprised if they weren't as ready as NW for Y1 getting started.

It seems to me that Boeing would be doing well to move on Y1 as soon as possible, simply because it would push Airbus into following with a matching investment. That would leave Boeing to move on Y3 when the major 787 work was done, hopefully keeping the market between a NB and the 350 to themselves.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-18 20:07:23 and read 17848 times.



Quoting Rheinwaldner (Reply 78):
You are aware that the A350 fuselage IS made without autoclaves?

News to me. What are they using, if not autoclaves? Unless Airbus has managed to keep an enourmous advance in resin technology very quiet, there's no compsoite technology that's commercializable at the moment that can match the fiber density and porosity of autoclaved CFRP.

Quoting Rheinwaldner (Reply 78):
The problem with the 787 skin is IMO if the damage cracks the surface and destroys the underlying stringers. The patch that needs to be made suddenly is very complex.

No worse than that same type of damage today, which isn't at all uncommon and is a stock repair, requiring no tooling, in most SRM's. Composite cracks, aluminum bends...either way, you don't get to straighten out bent aluminum stringers. You splice in new ones. Technology for splicing composites is about 40 years old.

Quoting Rheinwaldner (Reply 78):
For each patch an outside-mandrel has to be created and somehow inner structure has to be reconstructed.

This isn't a problem, at all, for current aircraft, and the repair technique is the same. Why wouldn't you apply the same repair? Boeing has already said, multiple times, that the same repair procedures would be used on the 787 as are done on current aircraft.

Quoting Rheinwaldner (Reply 83):
Both (full-barrel-replacement and patching) requires an enourmous effort.
I am convinced that replacing panels is easier.

I agree that replacing a panel is much easier than replacing a barrel. However, you're presenting this like replacing a panel is easy. Replacing a panel is still considerably harder than replacing a skin on a current aluminum airliner, and re-skinning repair is a *huge* job that's very rarely undertaken on aluminum airliners. I think you're grossly underestimating current repair techniques.

Quoting JoeCanuck (Reply 84):
Bonding makes for a much stronger join, which means less material. It would also provide a great seal.

This is definitely true, but the regulators are still somewhat gunshy about purely bonded joints because of a bad rap they got in the 70's. I suspect we're going to see bonding backed up by fasteners for at least the next generation of aircraft.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-18 20:29:09 and read 17801 times.



Quoting AutoThrust (Reply 89):
I don't, i just refute your comment making the 77W looking much more advanced then the A346.

And I never said it was "much more advanced". If you can quote me, I'd stand corrected. In the statement you quoted, I didn't even say it was "more advanced" just that it killed the market for the A346. I then explained, later, some of the advances over the previous 777.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-18 21:11:33 and read 17714 times.



Quoting Tdscanuck (Reply 91):
Quoting JoeCanuck (Reply 84):
Bonding makes for a much stronger join, which means less material. It would also provide a great seal.

This is definitely true, but the regulators are still somewhat gunshy about purely bonded joints because of a bad rap they got in the 70's. I suspect we're going to see bonding backed up by fasteners for at least the next generation of aircraft.

I agree...it'll be a bit of both since they have to make the joint airtight anyway, they might as well make it as strong as they can...and the world probably isn't quite ready for a rivetless airliner.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-18 22:44:31 and read 17630 times.



Quoting Rheinwaldner (Reply 83):
Both (full-barrel-replacement and patching) requires an enourmous effort.
I am convinced that replacing panels is easier. At least the plane remains in one piece. If you fix the plane with trestles it should be possible to replace quite large portions of the shell. The hydraulic and electric lines (+ air and water ducts....) can stay in place.

If the damage is so large that replacing an entire panel as used in the A350, you are looking at HUGE damage. Patching is going to be the way to go for most repairs, even ones that have damaged stringers as its easier to hand patch everything then tear down 1/16th of the plane or more just to pull the panel out. and I highly doubt you can just leave all the guts alone. Even if its all connected to the internal framing only, there is hundreds to thousands of fasteners that will be inaccessable if everything is left in place. And yes you will have to support the plane just like you took the whole section out since thats how monocoque construction works. take a big chunk of skin off and its going to bend/distort under its own wieght.

Barrel replacement would *ONLY* be used if the damage is extensive enough that the time saved and getting the plane back in service is cheaper than hand rebuilding the section with a "patch". Nothing new as Boeing has replaced the nose and forward fuselage of a 707 to get it back in service. Only now they can spin a barrel and stuff it, dreamlifter it + repair equipment to the location, then swap barrels. I'm sure they have run the calculations on this. It could be that its simply cheaper for the insurance company to foot the bill for a whole new 787 in these cases. Downtime on a frame is a HUGE expense, and with a high parts value, anything that can't be done with the typical patch procedures is going to be near writeoff levels of damage regardless of what and how the fuselage is made. We have seen this with the EK A346. Not much damage but not worth repair. The A350 wouldn't be any better as if you have to replace instead of patch, it would be two very large panels requiring the near complete disassembly of the aft section of the plane.

So speaking to the POSSIBLE engineering wise, barrel replacement is definitely easier than panel replacement at high levels of damage. Its just flat DESIGNED to quickly come apart at those seams with no difficult work. The panel approch that I've seen so far is far more conventional. Assemble panels into "barrels" then stuff them in a more conventional way. Taking ONE of the 4 panels out for replacement will require extensive structural bracing, just as much as if you were splitting the whole plane into sections. You have the internal wiring and plumbing to deal with.

Frankly I don't see the economics for either unless its happening to more than 1 plane a year needing very extensive structural repairs with associated damage to the guts under that section of fuselage. That said the A350 might make a case for D checks where you are already doing an extensive teardown. So you can replace a now very heavy panel that has been extensively patched with a fresh panel since patching adds a good bit of wieght. The 787 won't see as much benifit there.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-19 01:36:49 and read 17506 times.



Quoting JoeCanuck (Reply 84):
Quoting Rheinwaldner (Reply 78):
You are aware that the A350 fuselage IS made without autoclaves?

I searched but I couldn't find any EADS info about the 350 sections being cured outside an autoclave.



Quoting Tdscanuck (Reply 91):
Quoting Rheinwaldner (Reply 78):
You are aware that the A350 fuselage IS made without autoclaves?

News to me. What are they using, if not autoclaves? Unless Airbus has managed to keep an enourmous advance in resin technology very quiet, there's no compsoite technology that's commercializable at the moment that can match the fiber density and porosity of autoclaved CFRP.

I must admit that I have no hard proof. I realy though this quote would apply to the A350 but it was about the A400 (from this thread http://www.airliners.net/aviation-fo...l_aviation/read.main/4404435/1/#14 ) : Sad
"24 March 2009

The engineers of the former EADS site in Augsburg – part and headquarters of the new company Premium AEROTEC since January – have developed a process that allows large CFRP components to be manufac-tured not only at less cost and with lower weight, but also around 20 percent faster than before. This not only saves precious time, but also thousands of fasteners between the skin and the stringers – and thus weight. In comparison to conventional production methods, the prizewinning structure uses about 3,000 less fasteners."

Misleading for me was that the quote appeared in a thread about the A350.

But it could still be true. The full text from above quote is here:
http://www.eads.net/1024/en/pressdb/...90325_premium_aerotec_jec2009.html

The obvious facts are thus:
- Aerotec has the VAP (autoclave-less) technology
- Their VAP technology is unique worldwide and will not only set new standards in aircraft construction
- The 787 bulkhead is made by Aerotec too.
- Aerotec will produce A350 shells.

So yes, by changing your sentence: Airbus has managed to keep an enourmous advance in resin technology very quiet, because they have compsoite technology that's commercializable that can match the fiber density and porosity of autoclaved CFRP.

Will it be used for the A350? I don't know, but possibly. The closest hints are this:
http://www.reedexpo.com/images/10053...oad/PM_CE_Luftfahrt_05_2007_e.pdf, page 2
http://www.politik-und-sicherheit.de..._ab_07/Politik_Sicherheit_Nr6.pdf, page 3

And the ACCA also uses of large parts from autoclave-free production. B.t.w. more on topic: what are the prospects to transform the old alu-777 into a hybrid contruction the same way how the ACCA evolves from the Dornier-Jet? That could be a possible path (maybe even for the 737/A320 successors).

Quoting JoeCanuck (Reply 84):
Quoting Rheinwaldner (Reply 78):

Quoting JoeCanuck (Reply 74):
The panel joints will probably be bonded and fastened to the frame making it virtually impossible to separate the panel from the frame. The adhesives will likely be stronger than the panels themselves.

That would not be wise. IMO it will be fastened.

Bonding makes for a much stronger join, which means less material. It would also provide a great seal.

Bonding surely has advantages. Only the possible requirement to remove and replace the shell outweighs those advantages IMO.

Quoting JoeCanuck (Reply 84):
The 350 will also have internal stringers and ribbing. Their repair needs will be virtually identical.

Yes, if it is patched. The difference is the lower (but admittedly still high) barrier to replace a whole shell vs. replacing a whole barrel. If damages like on the picture in future would cause one of those measurements the aircraft with shells has an advantage. People have pointed out rightfully and I agree that such ultimate measures can only be the last highly unwanted option.

Quoting Ikramerica (Reply 85):
Says who? Unless you know the technology of the 787 inside and out, it's speculation, and the most pessimistic speculation at that.

Yes, I assume some things when debating about CFRP repairability. But I am an engineer and can picture such a situation before my inner eye. E.g. the different built-in strengths of the original barrel-wall also complicate the procedure to create a larger patch. I also accept if professionals tell me that my objections are not valid.

Quoting Ikramerica (Reply 85):
It's your opinion, so don't say "the problem is" as if that's established...

I said "the problem in my opinion is ...". How does that not comply with your style-requirements  Wink ?

Quoting Tdscanuck (Reply 91):
Quoting Rheinwaldner (Reply 83):
Both (full-barrel-replacement and patching) requires an enourmous effort.
I am convinced that replacing panels is easier.

I agree that replacing a panel is much easier than replacing a barrel. However, you're presenting this like replacing a panel is easy.

Then I presented wrong. In fact I rated replacing a whole barrel as big catastrophe. In the light of that replacing a whole shell is at least a small catastrophe too.

Quoting XT6Wagon (Reply 94):
If the damage is so large that replacing an entire panel as used in the A350, you are looking at HUGE damage.

 checkmark 

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-19 04:06:15 and read 17404 times.



Quoting Jambrain (Reply 88):
I don't know which law of physics says 2 are more economical then 4, if all key parameters are equal:-
i.e. pressure ratio, byepass ratio, turbine engine temperatures, turbomachinery effeciency

A couple of reasons why smaller engines are less efficient than large ones. First, a jet engine accelerates a column of air; the boundary between the moving column and the rest of the air is a source of turbulence and hence lost efficiency. So if you look at the boundary surface area it is proportional to the diameter of the column, while the volume of air being accelerated is proportional to the square of the radius. This means that the larger the diameter of the column, the less loss you get from this turbulence. This also applies to friction from the engine cowling. A very minor factor would be the frictional losses from the spool bearings and accessories driven by the engine; but I suspect they would be negligible

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-23 07:09:30 and read 16914 times.

Boeing released updated Payload-Range charts for the 777-200LR and 777-300ER, I am guessing to reflect the recent SFC improvements to the GE90-11xB.

The 777-300ER gains around 250nm across the board. MZFW range is now 5750nm (from 5500nm) and with full tanks, she can fly 8500nm (with 90,000 pounds of payload).

The 777-200LR gains around 100nm at MZFW (7600nm), moving out to about 250nm with full tanks (10500nm with 30,000 pounds of payload).

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-24 11:39:52 and read 16516 times.



Quoting Stitch (Reply 97):
Boeing released updated Payload-Range charts for the 777-200LR and 777-300ER, I am guessing to reflect the recent SFC improvements to the GE90-11xB.

The 77W now has roughly the same MZW range as a new build 77E, which will help put the last nail in the coffin of that aircraft in terms of sales.

Any idea what their 301/365 seat nominal ranges are now (the brochure range)? The Boeing website still says the old numbers.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SunriseValley
Posted 2009-05-24 16:16:02 and read 16310 times.



Quoting Ikramerica (Reply 98):
Any idea what their 301/365 seat nominal ranges are now (the brochure range)? The Boeing website still says the old numbers.

FWIW scaling the respective load/ range charts suggests "about" 9850 and 7900nm based on the "generic" OEW's of 320K and 370K pounds, respectively.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-24 18:29:55 and read 16201 times.



Quoting SunriseValley (Reply 99):
FWIW scaling the respective load/ range charts suggests "about" 9850 and 7900nm based on the "generic" OEW's of 320K and 370K pounds, respectively.

I doubt either of those are correct.

The previous brochure value for the 77L was 9380nm, and for the 77W, 7930nm (already higher than your number).

So one assumes that the 77L value goes up something between 100 and 250nm, and the 77W somewhere around 200-250nm.

So, just interpolating, you'd get about 9500nm and 8150nm respectively, but I was wondering if Stitch knew the new actual Boeing PR values, rather than interpolations.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SeaBosDca
Posted 2009-05-24 18:40:23 and read 16324 times.



Quoting Ikramerica (Reply 100):
So one assumes that the 77L value goes up something between 100 and 250nm, and the 77W somewhere around 200-250nm.

Imagine what would have happened at Airbus HQ around 2002 if someone had informed them that the 77W would turn out to be an 8000+ nm aircraft.  faint 

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-24 19:28:55 and read 16255 times.



Quoting Ikramerica (Reply 100):
So, just interpolating, you'd get about 9500nm and 8150nm respectively, but I was wondering if Stitch knew the new actual Boeing PR values, rather than interpolations.

Sorry, I do not. Boeing does not include a line at pax+bags in their charts like Airbus does.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-24 19:59:54 and read 16214 times.



Quoting SeaBosDca (Reply 101):
Imagine what would have happened at Airbus HQ around 2002 if someone had informed them that the 77W would turn out to be an 8000+ nm aircraft.

If they had known earlier than that (early enough in 2000), I believe they would have delayed (for redesign) or canceled the A346 and A345, and used the resources and research on an A330-500 and A330-600 with 105k RR engines (RR was ready to offer these to Boeing, remember). The fuselage, landing gear and other work from the A340NG series would have been directly applicable to the new models of A330, with engine and wing work to be redone to a great degree for "big twin" forces.

I think some A340NG customers would have canceled had they known, forcing this change. It would be somewhat akin to the first A350 proposals (but larger and years earlier), which would have changed history forever, as the 7E7/787 would have had to be different (as the 787-9 would be less compelling compared to the A355), the original A350 would not have been needed as they could offer an A334 to compete with the 788, etc. A cascade effect.

But Airbus (and Boeing and Airbus customers) really didn't know the full potential of the 77W until 2004, and by then, it was too late as the A346 and A345 were already in service.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Baroque
Posted 2009-05-24 22:01:41 and read 16120 times.



Quoting Rheinwaldner (Reply 95):
And the ACCA also uses of large parts from autoclave-free production.



Quoting Ikramerica (Reply 103):
The fuselage, landing gear and other work from the A340NG series would have been directly applicable to the new models of A330, with engine and wing work to be redone to a great degree for "big twin" forces.

But would that not have meant a heavier wing to add to the beefed up fuse to allow the length at that diameter????

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-24 23:11:21 and read 16056 times.



Quoting Baroque (Reply 104):
But would that not have meant a heavier wing to add to the beefed up fuse to allow the length at that diameter????

Absolutely. It would have required a very modified wing with a greater span and possibly greater dihedral to get a GE-90 sized engine on the wing. But still, a lot of the work from the A340NG would have been applicable to an A330NG instead.

The point is, I doubt they would have gone through with the A346 had an 7900 twin been what Boeing pitched. Instead, they would have worked their asses off to provide their own 7900nm twins. But Boeing pitched and sold a 7250nm 777-300ER, and that plane would not have been much more efficient, if any more efficient, than the A346 on equivalent routes, and would not be viable on routes the A346 could handle.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Baroque
Posted 2009-05-25 04:06:10 and read 15861 times.



Quoting Ikramerica (Reply 105):
The point is, I doubt they would have gone through with the A346 had an 7900 twin been what Boeing pitched.

All true, but if I understand what I have been told on these threads, the fuselage diameter for the A346 would have made the resulting plane too heavy without going back to the AlLi solution that Airbus has touched but not fully embraced. Or then again it could have been different. But a shoot out between a BIG RR A twin and the BIG GE B twin would have been interesting.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SunriseValley
Posted 2009-05-26 06:27:38 and read 15367 times.

Has anyone ever summarised the "upgrades" that might be possible to the 77L and 77W to reduce weight. It appears from the most recent updates to the load/range charts that SPC is being achieved in small increments over time. I would imagine that at least 10K pounds would be needed as a starter. I have read of a lighter wing box and welding instead of riveting but I would wonder if at this late stage welding is something Boeing would do if they have adopted CFRP as a standard for the future.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-26 07:24:57 and read 15236 times.

Boeing was working with airline interior suppliers to develop new, lighter-weight seats and cabin fixtures to lighten the empty weight of the 777-200LR and they have said they would look to implement 787 technologies and materials into the 777 "over time".

For QF, Boeing suggested six internal 1100 gallon fuel tanks which would have allowed the 777-200LR to fly SYD-LHR with 250 passengers and LHR-SYD with 200+ passengers (depending on winds aloft), however QF wanted 250 both ways all the time.

Re-profiling the 777 wing (ala the 747-8) might improve the cruise aerodynamics to lower cruise fuel burn and moving to Al-Li panels (as was considered during development) would lighten the structure a bit, though it might increase the production cost and Boeing's best weapon against the A350XWB at the moment is offering better pricing on the 777.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EA772LR
Posted 2009-05-26 07:57:02 and read 15179 times.



Quoting Stitch (Reply 97):
Boeing released updated Payload-Range charts for the 777-200LR and 777-300ER, I am guessing to reflect the recent SFC improvements to the GE90-11xB.

The 777-300ER gains around 250nm across the board. MZFW range is now 5750nm (from 5500nm) and with full tanks, she can fly 8500nm (with 90,000 pounds of payload).



Quoting Ikramerica (Reply 100):
So, just interpolating, you'd get about 9500nm and 8150nm respectively, but I was wondering if Stitch knew the new actual Boeing PR values, rather than interpolations.

Stitch (been a long time since I posted on here!) I was wondering if these numbers are correct, and I don't doubt you, or Ikramerica, but this further toughens the job Airbus has with the 3510 vs. the 77W. What do you think? And what other realistic possibilities do you think Boeing has in garnering even more range and less fuel burn out of the 77W to make it viable until Y3 is ready?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-26 10:00:18 and read 15034 times.



Quoting EA772LR (Reply 109):
I was wondering if these numbers are correct...

I did muff the payload figure at full tanks - it's 40,000 lbs, not the 90,000 I stated in Reply 97 (I mistakenly subtracted the 777-200LR's OEW, not the 777-300ER's).



Quoting EA772LR (Reply 109):
(Does) this further toughens the job Airbus has with the 3510 vs. the 77W?

Well it does make the 777-300ER that much more desirable, and it's already a powerfully desirable plane.

Per current published figures by Airbus on their website, the A350-1000XWB has an MTOW 50t lower then that of the 777-300ER and an MZFW 23t lower. It also tanks about 30,000 liters less fuel.

At MZFW, a 777-300ER can load 114t of fuel and an A350-1000XWB can load 84t - 26% less. At launch, Airbus claimed the A350-1000XWB would burn 25% less fuel per seat.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-26 10:59:46 and read 14933 times.



Quoting 757GB (Reply 75):
I'm not sure what specific system you're thinking of. What comes to mind for me is swing wing. I'm no engineer, but I understand that the swing wing has a weight penalty to it, as you have to carry around the mechanism required for it to function. Is this what you're referring to?

Variable sweep is just one form of variable geometry.
There is variable area, variable camber, variable chord, angle of attack, etc...

A variable geometry wing or "active wing" adapts a large part of a wing profile to the actual flight profile: speed, density altitude, mass of the airplane, center of gravity, so reducing unnecessary drag and as a result, fuel burn.

What I'm telling is nothing new... actually Airbus is already conducting research under the Smart Fixed-wing program for the A320RS.

I am more interested by open rotor than GTF for the B777RS.
The advantage of GTF is interesting compared to previous generation narrowbody engines like CFM-56 and CF-34 but I don't think that the GTF could be made interesting to compete against new generation HBP turbofans such as Trent XWB or GEnx where fans already turn at close to their optimum speed.



Panels or non-panels is not debatable.
And no dear friends, it's not going to be 20 meter panels for those pretending to know what they're talking about but do not.

Panels are way better for repair from day-to-day damage than full barrels but also in case of major damages. The reverse can never be true.
A small 3 inch² damage from birdstrike can keep your CFRP airplane on the ground for weeks, depending on the depth and shape of the damage, unless you can just change the panel and dispatch the airplane the next day.
CFRP can bear strong loads and has good fatigue resistance properties but has the property to shatter at impact, where Aluminium-alloys would only see distortion. A birdstrike can make damages that could keep an aircraft on the ground for many many days. Think further, any stone bouncing off the ground during take-off/landing roll can cause damage worth days of repairs...
If you don't believe it, here's a video: http://www.youtube.com/watch?v=xe-xkaUDtr4

(This shattering property, nevertheless increases crash survivability as impact force will be diluted by the shattering of the material.)

The CFRP skin will need to be checked more regularily for nicks and shattered material.
Any shattering is a huge weakness in the material and can develop into cracks. A further disadvantage of barrels is that undetected cracks can develop through an entire barrel structure while panels can limit the dispersion of failures.

As to bigger damages and replacing entire barrels, it's cheaper to write it off and order a new one. Panels save you big time.

The barrel-panel mass difference is not significant enough to be subjects of efficiency comparisons, but the B787 is risking very very high. After a few years we may see more 787's sitting waiting for repairs than flying.

Conclusion:
B777RS should go for CFRP panels or even better, Ti-Al alloy panel fuselage.
Better crash-survivability (both fire and impact), lower maintenance costs for slightly lower weight, only problem now is cost but new production processes for Ti-alloys are being researched right now which could significantly boost affordability of Titanium alloys.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EA772LR
Posted 2009-05-26 11:29:39 and read 14872 times.



Quoting NCB (Reply 111):
but the B787 is risking very very high. After a few years we may see more 787's sitting waiting for repairs than flying.

This seems like a bold statement considering the 787 hasn't even flown yet, let alone entered service. I still fail to see why Boeing would take such a risky approach, as well as the dozens of customers who are standing in line for them. After all is said and done, you may be right, but there seems to be a growing critique of Boeing's approach to the way they're using CFRP vs. Airbus's approach, which is confusing because neither manufacturer has EIS either respective airplane...  Confused

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-26 11:29:51 and read 14878 times.



Quoting NCB (Reply 111):
If you don't believe it

I guess we should just take your word for it, that the methodology Boeing is using to build CFRP is a brittle, fragile, easily damaged and hard to repair design?

Because that is 100% opposite to what they are marketing. Which would make it one of the biggest aviation scams of all time and bankrupt the company when the truth came out.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-26 11:54:51 and read 14833 times.



Quoting NCB (Reply 111):
Panels or non-panels is not debatable: And no dear friends, it's not going to be 20 meter panels for those pretending to know what they're talking about but do not.

Well excuse me for actually taking Airbus' statements and graphics showing skin panels of 13m, 16m and 18m for the A350-900XWB at face value. And I should have known better then to believe Airbus when they said the A350-1000XWB would be longer then the A350-900XWB, which would require panels of greater length.

Man, I got p'owned.  embarrassed 

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-26 12:12:20 and read 14765 times.



Quoting NCB (Reply 111):
Panels are way better for repair from day-to-day damage than full barrels but also in case of major damages. The reverse can never be true.
A small 3 inch² damage from birdstrike can keep your CFRP airplane on the ground for weeks, depending on the depth and shape of the damage, unless you can just change the panel and dispatch the airplane the next day.

I haven't seen any Airbus literature regarding whole panel replacement. Perhaps you could link to where they mention it.

I'd also be interested in specific information regarding the relative differences in the respective fuselages in regards to crack propagation.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: AutoThrust
Posted 2009-05-26 12:18:45 and read 14779 times.

Quoting NCB (Reply 111):
Panels save you big time.

Pardon my ignorance but won't that need lots of fasteners which add a lot of weight and complexity + drag penalty with the whole fuselage made of panels instead of shells?  

[Edited 2009-05-26 12:19:54]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-26 12:24:27 and read 14718 times.



Quoting NCB (Reply 111):
B777RS should go for CFRP panels or even better, Ti-Al alloy panel fuselage.
Better crash-survivability (both fire and impact), lower maintenance costs for slightly lower weight, only problem now is cost but new production processes for Ti-alloys are being researched right now which could significantly boost affordability of Titanium alloys.

So you know more about it then all of the Boeing engineers who, when debating the panels vs. barrels approach ended up with NONE of them favoring panels? The only problem was how to make the barrels, and once they figured that out nobody could make an argument that panels were better. Somehow I prefer to believe them, since the only knowledge I have of your qualifications on this subject is your profile, which is pretty unenlightening. As an engineer myself, I am firmly in the barrels camp (and have expounded on why numerous times.) The damage issue is a smokescreen; any damage that requires replacing either a panel OR a barrel is going to be massive, and is likely to be a WO in any case. Making the panels small enough to be easily replaceable defeats one of the main purposes, which is to reduce weight. The smaller the pieces (be they barrels or panels) the more joints; and joints require reinforcing material and fasteners, both of which add weight. The more and longer the joints, the more weight. The ideal would be to make the whole aircraft in one piece out of CFRP. Unfortunately, that is not yet feasible.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SeaBosDca
Posted 2009-05-26 12:27:59 and read 14723 times.



Quoting NCB (Reply 111):
A small 3 inch² damage from birdstrike can keep your CFRP airplane on the ground for weeks, depending on the depth and shape of the damage, unless you can just change the panel and dispatch the airplane the next day.

Boeing's barrels can be patched just like an aluminum fuselage.

Quoting NCB (Reply 111):
And no dear friends, it's not going to be 20 meter panels for those pretending to know what they're talking about but do not.

I suppose this is technically true, since they'll be 16. In any case, for minor damage, they'll be patched just like Boeing's barrels.

I thought we had got rid of these straw men years ago.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-26 15:08:41 and read 14540 times.



Quoting SeaBosDca (Reply 118):
Boeing's barrels can be patched just like an aluminum fuselage.



Quoting SeaBosDca (Reply 118):
In any case, for minor damage, they'll be patched just like Boeing's barrels.

Of course, but the issue is that the CFRP being fragile to impact forces and repair so time-consuming that swapping panels will become common practice. Except, if you can't swap panels, you're going to need to ground the aircraft until the repair is performed. Imagine if you got to ground a B787 for 3-4 weeks everytime a few birds or stones hit the fuselage.
With panels, an aircraft has a bad encounter, you assign a team of mechs, have them change the panel, do all the calibrations and testing and in less than 24 hours, the aircraft is ready to fly again.

I know that Boeing is regretting the CFRP barrel design, otherwise they wouldn't have beeen promoting it to Airbus this extensively. Boeing was telling the public that its barrel was better than the panel approach long before the A350 design freeze, hoping that Airbus would make the same pick. Airbus did, but realised and came back...

No sincerely, read this quote from Mitsubishi Heavy Industries, a B787 CFRP composite supplier, on the MRJ fuselage:

"We decided against a carbonfibre fuselage as regional aircraft are operated on high frequencies, so there is more likelihood of this more fragile material suffering damage from ground vehicles," Miyakawa says.

http://www.flightglobal.com/articles...on-mrj-cockpit-and-structures.html

It would be a total disaster to build a CFRP fuselage for an aircraft doing high frequencies, exposing it to many take-offs and landings and therefore higher risks of FOD and damage from ground vehicles.

CFRP still makes sense for low-frequency flying longhaul aircraft, except that when it happens that there is damage to the fuselage and there is going to be quite often, it's going to be alot more messy with the barrel than with the panel concept.
Bombardier C-series also chose Al-Li instead of CFRP for a reason...

Quoting SEPilot (Reply 117):
So you know more about it then all of the Boeing engineers who,

I don't, but you seem to imply that Airbus and MHI engineers are amateurs and Boeing engineers visionarians? I'm sure that many Boeing engineers did not agree with building a CFRP barrel structure but that the B787 weight was more important at the time.

As said, CFRP is interesting for its structural strength, but it's low strength against impact doesn't make it the best pick for the fuselage... even less for a non-panel structure.

Don't get too frustrated though, Boeing fans.
I'm no particular A or B or BBD or EMB fan, but I tend to be disappointed on the B787 as I find so many concepts of it to be unnecessarily artificial: non bleed-air, all-electric plane concept, CFRP fuselage, CFRP barrel.

Evolution is nice, except Boeing will IMO not be able to deliver what they sell, the perfect aircraft every airline dreams of.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-26 17:11:05 and read 14416 times.



Quoting NCB (Reply 119):
I don't, but you seem to imply that Airbus and MHI engineers are amateurs and Boeing engineers visionarians? I'm sure that many Boeing engineers did not agree with building a CFRP barrel structure but that the B787 weight was more important at the time.

The reason (from what I've been able to gather) that Airbus did not go for barrels was that they were playing catch-up with Boeing and did not feel they had the time to develop a way to build barrels without infringing on Boeing's patents. John Leahy tried to pitch the panels as being better, but if you believe him I've got a deal for you on a bridge in Brooklyn. The fact is that a panel replacement will be every bit as difficult (i.e. unfeasible) as a barrel replacement; once you take out one panel you have destroyed the structural integrity of the aircraft, and it would have to be heavily supported. That is not even considering the amount of disassembly that would be required to access all of the fasteners. As to MHI, they are building a regional jet, and the benefits of CFRP are less the smaller the airframe, plus it is the first time that they have built an airliner, so they may have preferred to stick to more traditional construction. Everything I have read about CFRP leads me to believe that it is MUCH more resistant to damage than aluminum; I think you are vastly overstating the problems. It is not "brittle" or "fragile" at all, but can withstand impacts without damage that would severely dent aluminum. When it does give it does not shatter, but disintegrates locally at the point of impact, with the rest of the structure staying intact. I think you will see that once the 787 and A350 enter service that the amount of time spent repairing damage is far less, not more. Just look at what's happened with boats; fiberglass boats have been around for decades, and they stand up far better than aluminum ones, and bounce off rocks and other obstacles that would severely dent aluminum boats, and CFRP is a lot tougher than fiberglass.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-26 17:46:27 and read 14367 times.



Quoting NCB (Reply 119):

Of course, but the issue is that the CFRP being fragile to impact forces and repair so time-consuming that swapping panels will become common practice. Except, if you can't swap panels, you're going to need to ground the aircraft until the repair is performed. Imagine if you got to ground a B787 for 3-4 weeks everytime a few birds or stones hit the fuselage.
With panels, an aircraft has a bad encounter, you assign a team of mechs, have them change the panel, do all the calibrations and testing and in less than 24 hours, the aircraft is ready to fly again.

I'm still curious about where you got this information. I did a quite extensive search and I couldn't find any specific information regarding the Airbus repair procedures and panel replacement.

Boeing's repair procedures have been approved by the FAA and I don't recall there were any major issues. A CFRP plane must meet the same safety and impact standards as an aluminum one.

Quoting NCB (Reply 119):

I know that Boeing is regretting the CFRP barrel design,

Can you support this statement with direct quotes from Boeing?

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-26 18:27:47 and read 14310 times.



Quoting NCB (Reply 111):
Panels are way better for repair from day-to-day damage than full barrels

No, they're not. A day-to-cay repair cannot involve replacement of a panel or barrel, so the comparison is totally moot.

Quoting NCB (Reply 111):
but also in case of major damages. The reverse can never be true.

Yes, it can. A barrel is a self-supporting structure that, as part of the assembly process, can be connected and disconnected from the other parts of the airplane. A panel is not self-supporting and requires a jig to hold the rest of the airplane in position.

Quoting NCB (Reply 111):
A small 3 inch² damage from birdstrike can keep your CFRP airplane on the ground for weeks, depending on the depth and shape of the damage, unless you can just change the panel and dispatch the airplane the next day.

This is so ridiculous as to make me wonder if you have ever seen an SRM. A 3 in2 damage, in aluminum or CFRP (or Ti or fiberglass or Kevlar or...) is a trivial repair and takes a few hours. All of these techniques exist, today, for current production airliners. Changing a panel is akin to reskinning an airliner (worse, since Airbus's proposed panels are bigger than normal skins) and, in no way shape or form, can be done for the next day.

Quoting NCB (Reply 111):
CFRP can bear strong loads and has good fatigue resistance properties but has the property to shatter at impact, where Aluminium-alloys would only see distortion.

Not at the same loading they won't. Composite shatters under forced displacement, not forced stress. The latter is far more common.

Quoting NCB (Reply 111):
A birdstrike can make damages that could keep an aircraft on the ground for many many days. Think further, any stone bouncing off the ground during take-off/landing roll can cause damage worth days of repairs...

No, it won't. How dumb, exactly, do you think Boeing and Airbus are? Panels vs. barrels makes no difference for impact damage, so you're essentially saying that Airbus and Boeing's flagship new aircraft are less durable than a Cessna.

Quoting NCB (Reply 111):
If you don't believe it, here's a video: http://www.youtube.com/watch?v=xe-xk...UDtr4

That appears to be a forced displacement test. Aluminum would do essentially the same thing, only with more distortion.

Quoting NCB (Reply 111):
The CFRP skin will need to be checked more regularily for nicks and shattered material.

Why? Do CFRP airplanes somehow attract more FOD?

Quoting NCB (Reply 111):
A further disadvantage of barrels is that undetected cracks can develop through an entire barrel structure while panels can limit the dispersion of failures.

How in the world could a crack through the entire barrel structure be undetectable? You don't think the pilots will notice the giant crack running half way around the fuselage?

Quoting NCB (Reply 111):
B777RS should go for CFRP panels or even better, Ti-Al alloy panel fuselage.

Do you have any idea how much a Ti fuselage would cost?

Quoting NCB (Reply 119):
Of course, but the issue is that the CFRP being fragile to impact forces

You appear to be grossly generalizing your knowledge of CFRP. Impact resistance is primarly a matrix property, not a fiber property, and aerospace CFRP matricies are specifically designed for high impact resistance. I've got a chunk of 777 vertical fin (same CFRP as in the 787) and you can whale on it with a hammer all you like, no big deal. Much much more impact than any FOD or bird would imply.

Quoting NCB (Reply 119):
and repair so time-consuming that swapping panels will become common practice.

Swapping panels is *hugely* time consuming. Reskinning is about the last repair you ever want to do (except maybe a spar splice) and takes days or weeks, *if* you have the parts and tooling available, which almost no airlines do.

Quoting NCB (Reply 119):
Except, if you can't swap panels, you're going to need to ground the aircraft until the repair is performed

Right. Which is why airlines do a repair. This is what they do today, this is what they'll do on the 787 and A350.

Quoting NCB (Reply 119):
With panels, an aircraft has a bad encounter, you assign a team of mechs, have them change the panel, do all the calibrations and testing and in less than 24 hours, the aircraft is ready to fly again.

What crew on earth can do a full reskin in 24 hours?

Quoting NCB (Reply 119):
"We decided against a carbonfibre fuselage as regional aircraft are operated on high frequencies, so there is more likelihood of this more fragile material suffering damage from ground vehicles," Miyakawa says.

You've completely overlooked the most relevant part of that quote..."regional aircraft." CFRP does not scale down well because you pass through the point where you're strength critical to where you're impact critical, and you loose the weight advantage. If you design by strength on a small aircraft, you're skins are so thin you have an impact problem. If you design for impact at that size, you loose the weight advantage.

Quoting NCB (Reply 119):
Don't get too frustrated though, Boeing fans.
I'm no particular A or B or BBD or EMB fan

Or material properties, apparently.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SeaBosDca
Posted 2009-05-26 20:51:58 and read 14188 times.



Quoting Tdscanuck (Reply 122):

Tom.

Thank you for a very careful and informative post.  Smile  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stressedout
Posted 2009-05-26 21:42:30 and read 14138 times.

Further to Tom's excellent post:

Quoting EA772LR (Reply 112):

Panels are way better for repair from day-to-day damage than full barrels but also in case of major damages.

This is incorrect. For day to day repairs there will be little difference between repairing the two systems.

Quoting EA772LR (Reply 112):
A small 3 inch² damage from birdstrike can keep your CFRP airplane on the ground for weeks, depending on the depth and shape of the damage, unless you can just change the panel and dispatch the airplane the next day.

This is not correct. I have personally practiced a repair of 6 inch diameter on the material of question and completed the repair in a matter of hours. With regard to replacing a panel; that will never ever happen in 24 hours. If the damage is so extensive as to require a panel replacement this will constitute an AOG situation and will probably take at minimum a week from the time of the damage to accomplish.

Quoting EA772LR (Reply 112):
CFRP can bear strong loads and has good fatigue resistance properties but has the property to shatter at impact, where Aluminium-alloys would only see distortion. A birdstrike can make damages that could keep an aircraft on the ground for many many days. Think further, any stone bouncing off the ground during take-off/landing roll can cause damage worth days of repairs...

The epoxy (the matrix of the composite) used by Boeing (and Airbus I assume) is a toughened epoxy. This stuff is so much tougher than aluminum it is not even funny. No stone bouncing off the runway will be grounding an airplane for days.

Quoting EA772LR (Reply 112):
Any shattering is a huge weakness in the material and can develop into cracks. A further disadvantage of barrels is that undetected cracks can develop through an entire barrel structure while panels can limit the dispersion of failures.

I am not sure what you mean by "shattering". Visible damage would need to be fixed when it's found but barely visible impact could remain and the stresses will be low enough that the delaminations will not propagate. Regarding the second part of the comment, this is ludicrous as well. Although I am not an expert on the 787 design, I am sure a crack (which would have a very tough time propagating in CFRP) would stop or turn at a stringer. Furthermore assuming it did grow to be of some length the fuselage wouldn't hold pressure or a piece of the skin would blow off causing a rapid decompression. Rest assured it won't develop through an entire barrel.

Quoting Ikramerica (Reply 113):
The barrel-panel mass difference is not significant enough to be subjects of efficiency comparisons, but the B787 is risking very very high. After a few years we may see more 787's sitting waiting for repairs than flying.

We will see about which system is better. Based on simple mechanics I would say the barrel approach is better; longitudinal stress in a cylinder is 1/2 of hoop stress. Joints in composites tend to add weight and the panel method will have lots of highly stressed joints. The barrel approach isn't risking anything that about 250 highly intelligent stress engineers haven't thought about. Regarding the last statement, it made me wonder if your entire post was some sort of joke.

All for now and cheers.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-26 23:39:36 and read 14045 times.



Quoting Stressedout (Reply 124):
Further to Tom's excellent post:

You quoted each and every quote incorrectly, as EA772LR nor I wrote any of those things you quoted.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-27 00:32:00 and read 14068 times.



Quoting NCB (Reply 119):
I know that Boeing is regretting the CFRP barrel design, otherwise they wouldn't have beeen promoting it to Airbus this extensively. Boeing was telling the public that its barrel was better than the panel approach long before the A350 design freeze, hoping that Airbus would make the same pick. Airbus did, but realised and came back...

You go further than I would. Though I am quite sure that the barrel apporach IS overrated some of your accusations seem exaggerated.

Quoting NCB (Reply 119):
"We decided against a carbonfibre fuselage as regional aircraft are operated on high frequencies, so there is more likelihood of this more fragile material suffering damage from ground vehicles," Miyakawa says.



Quoting NCB (Reply 119):
Bombardier C-series also chose Al-Li instead of CFRP for a reason...

Primary reason for this could be lack of skills to make a whole CFRP fuselage. I doubt that much more companies than Boeing and Airbus are able to develop and perform large scale manufacturing of such structures.
On the other hand if one would want to optimize the fuselage for high-frequency, short-range planes a possible design could look like this: hybrid metal-CFRP fuselage with panels. This would allow to make the lower part of the fuselage (which is exposed solely to ground damage) out of aluminium. The upper parts could be realized in CFRP to realize the best weight efficiency.

Quoting SEPilot (Reply 120):
The reason (from what I've been able to gather) that Airbus did not go for barrels was that they were playing catch-up with Boeing and did not feel they had the time to develop a way to build barrels without infringing on Boeing's patents.

That is pure speculation. There is no evidence for this.

Quoting SEPilot (Reply 120):
The fact is that a panel replacement will be every bit as difficult (i.e. unfeasible) as a barrel replacement; once you take out one panel you have destroyed the structural integrity of the aircraft, and it would have to be heavily supported.

Yes, but that is no big deal. Replacing whole barrels needs that supportment too. In addition replacing barrels includes all the tasks and difficulties that are done on the Boeing FAL. If this procedure is foreseen to be executed all over the world (because such damages must be fixed where they happen) it means that a FAL-like infrastructure must be installable everywhere.

Quoting SEPilot (Reply 120):
It is not "brittle" or "fragile" at all, but can withstand impacts without damage that would severely dent aluminum.

As far as I understood this brings up the problem of damage detection. If it makes "bang" and there is no visible damage how can you be sure that the skin is faultless? Airbus has developed a sandwich structure with a very thin outer skin. The idea is that as long as the outer skin has not clearly visibly dents the underlying structure must be 100% sound.

Quoting Tdscanuck (Reply 122):
Yes, it can. A barrel is a self-supporting structure that, as part of the assembly process, can be connected and disconnected from the other parts of the airplane

Only that the separation of barrels implies that all the connections (electric, hydraulic, mechanical, air, water, oxygen) need to be separated and rejoined too. System-wise a whole different category of undertaking.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-27 03:28:29 and read 13946 times.



Quoting Rheinwaldner (Reply 126):
That is pure speculation. There is no evidence for this.

There were statements by Airbus officials that were on this forum to that effect; I cannot find them at this point. But you are correct, it is mostly speculation, but I did not claim it was authoritative.

Quoting Rheinwaldner (Reply 126):
Yes, but that is no big deal. Replacing whole barrels needs that supportment too.

Exactly. I am merely stating that the panel approach is in no way superior to barrels from a replacement standpoint.

Quoting Rheinwaldner (Reply 126):
As far as I understood this brings up the problem of damage detection. If it makes "bang" and there is no visible damage how can you be sure that the skin is faultless?

My understanding is that Boeing has addressed the damage detection issue adequately; after all, they are using CFRP on some of the most critical parts of the 777, i.e. the empennage. I do not know exactly what their procedures are, but I am not willing to accept uninformed speculation that there is a problem. One of the important features of CFRP is that it is NOT prone to crack propagation, and so local damage will not tend to spread.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-27 06:19:22 and read 13770 times.



Quoting SEPilot (Reply 127):
Quoting Rheinwaldner (Reply 126):
Yes, but that is no big deal. Replacing whole barrels needs that supportment too.

Exactly. I am merely stating that the panel approach is in no way superior to barrels from a replacement standpoint.

True, but only from the supportement standpoint. Separating the fuselage in pieces means disconnecting a lot more than would be required if a panel (= part of the skin but no inner parts) gets replaced. In the end separating barrels means somehow to tear apart the interior too. Plus the interior of the defective barrel has to be dismantled completely AND after that has to be reconstructed fully in the new barrel! There is more than the eye can see first. I once stated that replacing whole barrels is a medium catastrophe! Very costly!
I am aware that replacing panels is costly too but never on the same scale!

Quoting SEPilot (Reply 127):
My understanding is that Boeing has addressed the damage detection issue adequately; after all, they are using CFRP on some of the most critical parts of the 777, i.e. the empennage.

I agree with that. There must be a reasonable solution for this. It is important because:
- The fuselage is a much larger "target" for damage than anything before
- It is much more exposed to be hit by ground vehicles than the empennage

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EA772LR
Posted 2009-05-27 07:07:23 and read 13678 times.



Quoting Ikramerica (Reply 125):
Quoting Stressedout (Reply 124):
Further to Tom's excellent post:

You quoted each and every quote incorrectly, as EA772LR nor I wrote any of those things you quoted.

Thank you for pointing that out Ikramerica  checkmark 

Quoting Rheinwaldner (Reply 128):
I once stated that replacing whole barrels is a medium catastrophe! Very costly!
I am aware that replacing panels is costly too but never on the same scale!

Rheinwaldner, I agree with the first part of your post, but I cannot see how you can make the accusation you make claiming replacing a panel would never be as costly as replacing a barrel. From my understanding, as well as others more informed on CFRP, if an airline has to replace a barrel or panel, either or will be considered a WO, because that much damage would probably spell more problems than a simple "replacement" of a panel or barrel.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-27 07:28:12 and read 13637 times.


  • No airline is going to buy a plane that cannot be repaired or is so fragile it will spend the majority of its operating life in a hangar being repaired or written-off in the first incident.

  • No finance company is going to finance a plane that will not generate a return because it's always on the ground being repaired or will be written-off in the first incident and not in the air carrying paying passengers and freight.

  • No insurer will issue a policy on an airplane that cannot be repaired or is so fragile it will spend the majority of its operating life in a hangar being repaired or will need to be written-off in the first incident.

Ergo, the 787 and the A350XWB can be repaired and they are not fragile because airlines are buying them, financing companies are willing to loan the money so the airlines can buy them and insurers are willing to issue policies on them.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Brendows
Posted 2009-05-27 07:40:51 and read 13614 times.



Quoting Rheinwaldner (Reply 78):
My point here was autoclave-free production. You won't find sources which state the use of autoclave being as future-proof. If possible you avoid them.

Ah, I'm sorry, I thought you meant panels/shells vs. barrels. And yes, I agree that autoclaves should be avoided if possible.

Quoting Rheinwaldner (Reply 78):
You are aware that the A350 fuselage IS made without autoclaves?

I haven't seen any press releases with that kind of information. Something that could point in the other direction is the fact that Spirit has ordered autoclaves for their new A350XWB production facility in North Carolina.

Quoting Rheinwaldner (Reply 78):
There are documents in the internet that show clearly that CFRP is not just CFRP. 2nd Generation CFRP will be much better regarding weight and cost than the current materials and methods.

I don't disagree with you here, I was pointing to the production concepts the different manufacturers use.

Quoting Tdscanuck (Reply 91):
I agree that replacing a panel is much easier than replacing a barrel. However, you're presenting this like replacing a panel is easy. Replacing a panel is still considerably harder than replacing a skin on a current aluminum airliner, and re-skinning repair is a *huge* job that's very rarely undertaken on aluminum airliners. I think you're grossly underestimating current repair techniques.

 checkmark 
The way I see it: if a barrel or shell has to be removed, the damage is so severe that the airliner will be out of service for weeks anyway. When removing a shell you have to have access to the frames it's connected to, which means removal of much of the interior fitting in that section and lots of fasteners.

Quoting NCB (Reply 119):
I'm no particular A or B or BBD or EMB fan, but I tend to be disappointed on the B787 as I find so many concepts of it to be unnecessarily artificial: non bleed-air, all-electric plane concept, CFRP fuselage, CFRP barrel.

Evolution is nice, except Boeing will IMO not be able to deliver what they sell, the perfect aircraft every airline dreams of.

Well, a lot of airline CEOs thinks otherwise, I know who I would listen to.

Quoting Rheinwaldner (Reply 126):
Primary reason for this could be lack of skills to make a whole CFRP fuselage.

I agree, and as others have mentioned - how the use of CFRP doesn't scale down that well.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-27 07:53:01 and read 13584 times.



Quoting Rheinwaldner (Reply 128):
True, but only from the supportement standpoint. Separating the fuselage in pieces means disconnecting a lot more than would be required if a panel (= part of the skin but no inner parts) gets replaced.

I disagree. I think replacing a panel will be every much as difficult as replacing a barrel. As others have stated, it is highly likely to be a WO in either case. To replace a panel will also involve completely disassembling much of the interior to get at the fasteners attaching the panels to the hoop frames.

Quoting Rheinwaldner (Reply 128):
- It is much more exposed to be hit by ground vehicles than the empennage

I think that the empennage (especially the elevators) are pretty vulnerable as well.

Quoting Stitch (Reply 130):
Ergo, the 787 and the A350XWB can be repaired and they are not fragile because airlines are buying them, financing companies are willing to loan the money so the airlines can buy them and insurers are willing to issue policies on them.

 checkmark  And considering that the 787 is the fastest selling airliner in history I think the market has voted. Maybe they've all been suckered and it will prove to be a gigantic fiasco; the moon may also depart its orbit and fall into the Pacific tomorrow.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-27 07:53:45 and read 13623 times.



Quoting EA772LR (Reply 129):
if an airline has to replace a barrel or panel, either or will be considered a WO, because that much damage would probably spell more problems than a simple "replacement" of a panel or barrel.

That can easily be the case. I don't know. If replacement is not feasible at all and each case would a WO then we will probably see more frequent write-offs because of that. In my thread about CFRP fuselages ( http://www.airliners.net/aviation-forums/tech_ops/read.main/216974/ ) I made a forecast that the first 787 will be written off because of a damage that would have been repairable on an metal plane. Like this:

View Large View Medium
Click here for bigger photo!

Photo © Jarett Sirko



Another of my forecasts was: that you will see the A350 getting new panels in comparing cases that caused a 787 to be scrapped.

I am quite sure that if ever a panel or a barrel has to be replaced the panel is easier.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EA772LR
Posted 2009-05-27 08:42:07 and read 13537 times.



Quoting Brendows (Reply 131):
Quoting Rheinwaldner (Reply 78):
You are aware that the A350 fuselage IS made without autoclaves?

I haven't seen any press releases with that kind of information. Something that could point in the other direction is the fact that Spirit has ordered autoclaves for their new A350XWB production facility in North Carolina.

Hmmm  scratchchin  It can't be both ways, so is Airbus planning to use autoclaves for A350 CFRP or not??

Back on topic, Boeing doesn't need to do anything yet with the 777 IMHO. With the SFC improvements recently, and more efficiency gains made in the future, why would Boeing do anything drastic yet.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-27 08:58:48 and read 13496 times.



Quoting Rheinwaldner (Reply 133):

I am quite sure that if ever a panel or a barrel has to be replaced the panel is easier.

I will dispute you on this; I believe it will actually be easier to replace a barrel, and I speak as one who has been repairing machines all my life, including airplanes. But what you are overlooking is the fact that CFRP is much, much more resistant to damage than aluminum, and will withstand impacts without damage that would cause significant damage to aluminum. I predict that insurance claims for minor damage will be significantly LOWER for the 787 and A350, and writeoffs will only happen for major mishaps, such as bad landings or aborted takeoffs. The 777 went for what? 13 years? before having a single writeoff; the 787 and A350 may well exceed that record.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-27 09:16:16 and read 13469 times.

You do not need to have a PhD in Materials Science to understand that two things made of the same material can have different properties.

A soda can and a commercial airliner are both skinned in aluminum. However, if you punch a soda can, chances are the can will buckle. If you punch an airliner, chances are (the bones in) your hand will buckle.

Aerospace CFRP has different properties then the CFRP in a ski or a tennis racket because they are subjected to different forces and are designed to respond differently to the forces they are subjected to. You cannot look to a weak, flexible CFRP object and claim that is how a 787 or A350XWB will respond to the same forces any more then you can look at a soda can and say that is how a 777 or A330 will respond to the same forces.

I believe any impact an Al-skinned airliner can survive a 787 or A350XWB can survive. I believe any damage that can be repaired on an Al-skinned airliner can be repaired on a 787 or an A350XWB.

I do not believe that an A350XWB is inherently easier to repair then a 787. I do not believe Airbus went with panels for maintenance, but instead for ease of assembly and a quicker EIS (thanks to not needing to develop new production and assembly techniques and train staff on them).

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-27 10:49:55 and read 13324 times.



Quoting Rheinwaldner (Reply 128):
True, but only from the supportement standpoint. Separating the fuselage in pieces means disconnecting a lot more than would be required if a panel (= part of the skin but no inner parts) gets replaced. In the end separating barrels means somehow to tear apart the interior too. Plus the interior of the defective barrel has to be dismantled completely AND after that has to be reconstructed fully in the new barrel! There is more than the eye can see first. I once stated that replacing whole barrels is a medium catastrophe! Very costly!
I am aware that replacing panels is costly too but never on the same scale!

You miss the point of barrel replacement. IF its more economical to replace a barrel than write off the plane, you will have a barrel prestuffed with all the wiring and everything else needed as if it was going to be assembled into a new plane. Far quicker to have your suppliers bust out a copy of the old planes wiring to put in the new barrel than to strip the old, repair everything to like new standards and restuff the new barrel with old.

Both methods (barrel and panel) will require the plane to be fully supported in the area getting repaired. Do a panel unsupported and you will be lucky if the only thing that happens is the new panel doesn't fit due to stress distortion. Some panel removals will cause the plane to break apart if unsupported.

As I've said before I am sure boeing has studied it, and the lack of new of development of portable equipment to support barrel swapping says its not economical to do. Airbus has the SOLE advantage that in a heavy check when everything is stripped down to nearly nothing, you can replace a panel that is now much heavier due to extensive repairs easier than replacing a full barrel.

Quoting Rheinwaldner (Reply 133):
That can easily be the case. I don't know. If replacement is not feasible at all and each case would a WO then we will probably see more frequent write-offs because of that. In my thread about CFRP fuselages ( http://www.airliners.net/aviation-forums/tech_ops/read.main/216974/ ) I made a forecast that the first 787 will be written off because of a damage that would have been repairable on an metal plane. Like this:

That damage wouldn't be hard at all to fix on a CRFP plane. Even if it was the exact same size which means a far harder hit than the AL plane took. Sure the plane will be a good bit heavier when its all patched up, but its repairable. Just like AL planes, CRFP planes will have warts and scars where extra material is used to ensure the patching is strong enough to justify as just as strong as new.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-27 11:10:14 and read 13291 times.



Quoting Stitch (Reply 136):
I do not believe that an A350XWB is inherently easier to repair then a 787. I do not believe Airbus went with panels for maintenance, but instead for ease of assembly and a quicker EIS (thanks to not needing to develop new production and assembly techniques and train staff on them).

You also have to look at the size of the 787 autoclaves, and that the A350 autoclaves would need to be even larger. Adding an autoclave of this size is not simple or cheap, which makes ramp up of the program to meet production demand that much more difficult past a certain point. The panel approach would mean smaller diameter autoclaves could be used, autoclaves that are less expensive to acquire and are more easily reused for other things in the future. That's a lower sunk cost and an advantage for Airbus.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stressedout
Posted 2009-05-27 11:30:10 and read 13251 times.



Quoting Ikramerica (Reply 125):
You quoted each and every quote incorrectly, as EA772LR nor I wrote any of those things you quoted.

and

Quoting EA772LR (Reply 129):
Thank you for pointing that out Ikramerica checkmark

I sincerely apologize to you both. I meant to quote NCB each and every time in my Reply # 124. I guess that's what happens when one replies at 11 pm (plus I haven't posted that many replies).

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-27 11:32:11 and read 13247 times.



Quoting Stressedout (Reply 139):
I sincerely apologize to you both. I meant to quote NCB each and every time in my Reply # 124. I guess that's what happens when one replies at 11 pm (plus I haven't posted that many replies).

No problem. It happens to the best of us, but usually, at least one quote is right...  Wink

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EA772LR
Posted 2009-05-27 11:45:25 and read 13220 times.



Quoting Stressedout (Reply 139):
I sincerely apologize to you both. I meant to quote NCB each and every time in my Reply # 124. I guess that's what happens when one replies at 11 pm (plus I haven't posted that many replies).

No worries, I knew it was just a glitch.  wave 

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-27 12:42:46 and read 13154 times.



Quoting Tdscanuck (Reply 122):

No, they're not. A day-to-cay repair cannot involve replacement of a panel or barrel, so the comparison is totally moot.

Let me appologize to NCB, and everyone else on the thread, for my Reply 122. Although I stand by the technical side of it, the tone is unacceptable. I sound like an arrogant prick, and there's no excuse. So, to attempt to redeem myself a little, let me put in some of the information that I should have put in the first time.

Quoting Tdscanuck (Reply 122):
This is so ridiculous as to make me wonder if you have ever seen an SRM.

To clarify a lot more...the SRM contains pre-approved repairs for essentially every piece of structure on the aircraft (excepting some of the safe-life stuff). This includes skins, frames, and stringers (for the fuselage), and essentially all panels/stringers/spars for the wings/empennage. Today, we've got lots of CFRP running around in these applications, and composite repairs exist for damage to those structures. Those same repairs apply equally well to any laminate (the CFRP can't tell if it's a thrust reverser, a stabilizer skin, or the fuselage). There is no reason, that I'm aware of, that existing composite repairs (which are considerably more capable than 3 in2) would not apply to the 787.

Quoting Tdscanuck (Reply 122):

Not at the same loading they won't. Composite shatters under forced displacement, not forced stress. The latter is far more common.

The concern over composite "shattering" comes from confusing what are really several separate properties...yield strength, ultimate strength, and fracture toughness. Yield strength is how much stress you can stand before permanent deformation. Ultimate strength is how much you can stand before failure (before your load capability starts to drop). Fracture toughness is how hard it is to grow a crack. You can have any combination of these properties, depending on the material.

Shattering is just what happens when the yield and ultimate strengths are really close together. You don't get any deformation...it just keeps taking load up until it fails, then it all comes apart. This has nothing to do with what the actual magnitude of the load is. Something like sugar candy has yield strength and ultimate strength essentially the same, but is incredibly weak. Something like china has yield strength and ultimate strength essentially the same, but is incredibly strong.

Fracture toughness is the one that really messes people up over composites...composites, especially aerospace composites, have extremely high fracture toughness. This means that, even when they crack, it's very difficult to make that crack grow. People tend to assume that all brittle materials (materials that shatter) must also have low fracture toughness...this is why things like glass and very high-strength steel don't take impact well. They have very low fracture toughness, so even tiny damage can very easily grow into a catastrophic crack. CFRP, as used in aerospace, however, has very good fracture toughness. Even if you hit it, and even if you damage it, it's very hard to grow the damage. As a result, CFRP laminates can take a fairly absurd amount of abuse and still maintain most of their strenght.

Quoting Tdscanuck (Reply 122):

Do you have any idea how much a Ti fuselage would cost?

NCB is right that an Al-Ti fuselage would have many very nice engineering properties, including great corrosion resistance. The problem isn't material performance, it's manufacturing cost. Ti is extremely expensive to start with. On top of that, it's very difficult to form. This is why most Ti components are either milled billets, or superplastically formed thin sheets. Neither method is very easy, or cheap, to apply to parts the size of normal fuselage skins. And, since the performance is fairly comparable to CFRP, it's tough to see how the economic case for Ti fuselage works out.

There's also the issue that Ti is probably too dense to be a really good skin material. The optimal material (for weight) for a particular application depends a lot on the loading. For shear panels (aka fuselage skins) aluminum alloys and CFRP are about as good as we know how to do. The loading on the skins is too low to make really really strong materials like steel or Ti weight competitive.

Quoting Rheinwaldner (Reply 133):
In my thread about CFRP fuselages ( http://www.airliners.net/aviation-forums/tech_ops/read.main/216974/ ) I made a forecast that the first 787 will be written off because of a damage that would have been repairable on an metal plane. Like this:

I'm not sure why you think that particular damage example would be a write off. It's repairable. Annoying, but repairable.

Quoting Rheinwaldner (Reply 133):
Another of my forecasts was: that you will see the A350 getting new panels in comparing cases that caused a 787 to be scrapped.

There's no particular reason you can't build a repair panel for a 787 that's analogous to a skin panel on an A350. If it's economical to do it on the A350, why wouldn't it be economical to do it on the 787?

Quoting Rheinwaldner (Reply 133):
I am quite sure that if ever a panel or a barrel has to be replaced the panel is easier.

If I had to plan the repair, I'd certainly rather do the barrel than the panel. Besides there being many more joints for the panel, the barrels already have all the connectors and hookups between them to separate barrels, since you're just reversing what was done in final assembly. I don't see this being the case for a panel.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EA772LR
Posted 2009-05-27 13:22:54 and read 13091 times.



Quoting Tdscanuck (Reply 142):

Wow Tom, thank you for the very informative post. I feel that I have just taken a crash course on CFRP (no pun intended).  checkmark 

It ought to be interesting to see how each method of applying CFRP works out-panel vs. barrel. It will be interesting to see how the maintenance costs and reliability pan between the two types of CFRP planes, for example, with an airline like SQ who will operate both 789/359.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-27 14:54:04 and read 12984 times.



Quoting EA772LR (Reply 143):
Wow Tom, thank you for the very informative post. I feel that I have just taken a crash course on CFRP (no pun intended).

I can only agree with this comment. Tom's post is very, very informative on the matter. Such posts are a joy to read.  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NorCal
Posted 2009-05-27 16:25:58 and read 12839 times.



Quoting NCB (Reply 145):
Many airline CEO's don't even know what makes aircraft fly... they are relying too much on Boeing's fabulous marketing stunt if I may call it so.

A CEO might not know all the details but airlines have engineering and maintenance departments filled with very bright people who analyze and give their opinions on aircraft. Everything from efficiency to repairability to interior comfort. They scrutinize these aircraft from both Boeing and Airbus because they cost hundreds of millions of dollars to buy. Those engineering and maitenance departments wouldn't get conned by Boeing.

Quoting Tdscanuck (Reply 142):

Thanks for dumbing that complicated stuff down for the rest of us  Smile Do you teach? If not you should consider it, you would be very good.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-28 10:41:20 and read 12557 times.



Quoting NorCal (Reply 145):
A CEO might not know all the details but airlines have engineering and maintenance departments filled with very bright people who analyze and give their opinions on aircraft. Everything from efficiency to repairability to interior comfort. They scrutinize these aircraft from both Boeing and Airbus because they cost hundreds of millions of dollars to buy. Those engineering and maitenance departments wouldn't get conned by Boeing.

The only thing I can tell you is that airline CEOs tend to talk only to maintenance supervisors who work mostly in offices. How many airlines have mx supervisors who have extensive experience with CFRP and most importantly, airliner CFRP fuselage repairability? Airlines only get a good idea of MX costs once they get hands-on experience with the aircraft.

Engineering and maintenance must sadly too often work with whatever aircraft their management buys.

Airlines tend to order blindly from major manufacturers such as Airbus and Boeing, before even the final configuration of the aircraft is decided upon. Airbus had 500 A350XWB orders before design freeze... Contracts are there to guarrantee economical performance of the ordered aircraft but I'm not sure maintainability of damage due to external factors (FOD) is included in these contracts.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-28 13:18:27 and read 12418 times.

With maintenance such a huge expense to an airline and considering that both Boeing and Airbus are forecasting huge mx savings, I rather doubt that any airline ceo is going to put billions of dollars in jeopardy without having his mx people verify those claims.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-28 13:31:20 and read 12388 times.

Well maybe Boeing will organize a "Ramp Rash Derby" with ZA997 and ZA998 when they've completed all their certification testing to see just how tough the birds really are.  Silly

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-28 13:51:25 and read 12351 times.



Quoting NCB (Reply 146):
The only thing I can tell you is that airline CEOs tend to talk only to maintenance supervisors who work mostly in offices. How many airlines have mx supervisors who have extensive experience with CFRP and most importantly, airliner CFRP fuselage repairability? Airlines only get a good idea of MX costs once they get hands-on experience with the aircraft.

Again, what is your authority? How many airline CEO's do you know? And where do you get such intimate knowledge on how CEO's do or do not get the specifics of how their hundred million dollar plus investments actually perform? You are painting a caricature that I suspect has little to do with reality. Most CEO's that I have worked for do not know all of the nuts and bolts of the business, but they all know who does, and the good ones listen to them. I am absolutely confident that the airline CEO's would not have flocked to the 787 and A350 the way they have even before either one has even been built, let alone flown, if they were not confident independent of Boeing's and Airbus's claims that the CFRP planes would not only cost them less to fly, but would be easier to maintain and that there would NOT be any big "gotchas" that you are so sure are going to pop up. And it is not just one or two airline CEO's, but most of them. Also, I do not think that many airlines let their CEO's decide on his own what planes to buy, but they have committees made up of knowledgeable people to study the proposals in detail. I don't think all of those people that have been involved in ordering the 787 and A350 could have all been duped.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-28 14:01:13 and read 12319 times.



Quoting SEPilot (Reply 149):
Also, I do not think that many airlines let their CEO's decide on his own what planes to buy, but they have committees made up of knowledgeable people to study the proposals in detail. I don't think all of those people that have been involved in ordering the 787 and A350 could have all been duped.

And I'm pretty sure major capital investments need to be approved by the BOD in most companies. CEO doesn't have the power to commit $5 billion on his/her own...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-28 14:19:46 and read 12374 times.

Quoting JoeCanuck (Reply 147):
With maintenance such a huge expense to an airline and considering that both Boeing and Airbus are forecasting huge mx savings, I rather doubt that any airline ceo is going to put billions of dollars in jeopardy without having his mx people verify those claims.

Actually MX savings on foreign airliners are very contradictory.
There will be savings thanks to maintenance-friendly designed airplanes, very true.
But the systems on board the airplanes are only becoming more complex and more numerous. There's more and more systems on aircraft and every single systems are becoming gradually complicated to improve performance. The actual philosophy is to increase complexity and as a result, mx costs, say by 1 buck to save 10 bucks on fuel.

Best proof of this evolution is the non-bleed air concept.
Bleed-air is a simple system to maintain on modern airliners.
On the 787 it's replaced by dozens of very complex systems that will increase mx costs, but improve fuel efficiency. (supposedly, but I have a doubt about it, as the weight and losses of the systems replacing bleed air will at least largely underplay the efficiency gain)

I think CFRP on 787 and A350 is one of these examples of "increase mx costs by a bit too burn alot less fuel" principle. The reduced mx costs of corrosion and fatigue resistance will be undermined by increased mx cost by weakness towards FOD.
But as A & B are starting to realise, the "burn alot less fuel" part is not playing out very well as CFRP in the way it is applied here is not as light as they imagined it would be.

As said, airline CEOs talk to consultants and MX supervisors working in offices most of the time, before ordering, very few of these are actual on-the field specialists. Most MX supervisors are know-it-all types and love to show off (by experience).
Only few people in the global aviation industry have the hands-on experience and research background to make these kind of calls.

Take for instance world's greatest airline's CEO, SUH of ILFC.
He says "do this or do that" to A & B but he doesn't have the technical expertise nor department to make design call, he only looks at economical performance.

That's why "launch customers" are so important to manufacturers. It gives other airlines the impression that the launch customer conducted the necessary research and deemed the aircraft suitable for service.
I know only 2 airlines in the world that have a dedicated department of specialists on the payroll to make these calls and CEO's who actually listen to their advise.
One of them is LH, that takes part on every new aircraft program (including the SSJ) which by the way is being very very careful about the 787/A350, and for a very good reason.   Wink

Most purchase decisions by airlines not having this sort of department are based on expected performance data provided by the manufacturer, without going into much detail about systems, etc....
The airlines that have the dedicated specialist department will analyse the aircraft from nose to tail and from design stage to the delivery and even ask for redesign of systems they deem not suitable.

[Edited 2009-05-28 14:32:13]

[Edited 2009-05-28 14:38:06]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-28 15:27:48 and read 12250 times.

A little edit: Dunno why that "foreign" appeared on the first line of previous post, can't edit anymore

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-28 15:29:40 and read 12259 times.



Quoting NCB (Reply 151):

Best proof of this evolution is the non-bleed air concept.
Bleed-air is a simple system to maintain on modern airliners.
On the 787 it's replaced by dozens of very complex systems that will increase mx costs, but improve fuel efficiency. (supposedly, but I have a doubt about it, as the weight and losses of the systems replacing bleed air will at least largely underplay the efficiency gain)

That really isn't proof...it's presumption. So far there is no proof that the bleedless system will have increased mx costs. That proof, if your presumption is is proven correct, won't come until the 787 has spent significant time in service.

Quoting NCB (Reply 151):
I think CFRP on 787 and A350 is one of these examples of "increase mx costs by a bit too burn alot less fuel" principle. The reduced mx costs of corrosion and fatigue resistance will be undermined by increased mx cost by weakness towards FOD.
.

So far, tests have indicated that CFRP is MORE resistant to fod damage.

Quoting NCB (Reply 151):
Take for instance world's greatest airline's CEO, SUH of ILFC.
He says "do this or do that" to A & B but he doesn't have the technical expertise nor department to make design call, he only looks at economical performance.

He also doesn't have the only say in the purchase of an aircraft type. It's ludicrous, to me, that billions of dollars would be spent based on chance. These people are, above every thing else, business people. Their job is to look at all costs, not just purchase price.

Every airline in the world is acutely aware of short and long term mx expenses and plans for them. An airline which doesn't do every bit of research it can before spending billions of dollars has only one future; death.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: FRNT787
Posted 2009-05-28 17:05:58 and read 12177 times.



Quoting AirNZ (Reply 68):
Yes, it's a valid enough point, but not one that his highly improbable either despite a lot of wishes on a.net (not meaning yourself at all). It must be appreciated that, while certainly possible, the disaster befallen the 787 programme in delays etc. does not automatically portray the same events for the A350. I feel this 'automatic' belief is too often overlooked/played upon here.

I agree with you completely on this. I think due to delays in the A380 and 787 people are assuming this will translate into similar delays in future programs. I have seen no reason to doubt Airbus's EIS figures yet. They were very wise to give themselves time to handle any remaining A380 problems they may have had...and allow enough time to create a strong offering.

Quoting NCB (Reply 119):
I know that Boeing is regretting the CFRP barrel design, otherwise they wouldn't have beeen promoting it to Airbus this extensively. Boeing was telling the public that its barrel was better than the panel approach long before the A350 design freeze, hoping that Airbus would make the same pick. Airbus did, but realised and came back...

Yes...this seems the most probable. Not to market to Airline execs their rationale to choose the Barrel method, but to trick Airbus into choosing it so both could have a plane that will be next to impossible to repair...but Airbus saw the light and went away from Boeing's trickery... That has to be the strangest comment I have ever read on here... and it reminds me of the Grave scene from The Phantom of the Opera.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-28 20:58:51 and read 12054 times.



Quoting NCB (Reply 151):
Bleed-air is a simple system to maintain on modern airliners.

It's "simple" in the sense that the maintenance procedures themselves are relatively easy. It's not "simple" in the sense of taking little work...pneumatics are routinely in the top 3-5 delay drivers on all aircraft. They're extremely maintenance prone systems. Electrical is, based on all available maintenance data, considerably better.

Quoting NCB (Reply 151):
On the 787 it's replaced by dozens of very complex systems

Not dozens, one. The pneumatic system was completely replaced by the electrical power system. It is, indeed, a very complex electrical system.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-28 22:55:11 and read 11976 times.



Quoting Tdscanuck (Reply 155):
Not dozens, one. The pneumatic system was completely replaced by the electrical power system. It is, indeed, a very complex electrical system.

A HUGE benifit will be diagnostics. Fixing a problem in a pnuematic system is a slice of hell starting with diagnostics. A good electrical system will tell you whats broken and thus just replace it and move on with life.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-28 23:40:10 and read 11941 times.



Quoting JoeCanuck (Reply 153):
So far, tests have indicated that CFRP is MORE resistant to fod damage.

Sorry but you don't know what you're talking about.
CFRP is very weak towards impact damage.  Wink

Here's some litterature for you:

Quote:
A350 XWB chief engineer Gordon McConnell says that the nose reprofile was made partly for improved aerodynamics and also to enable the overhead crew rest to be installed further forward and eliminate any encroachment in the passenger cabin.

He adds that strength requirements for birdstrike protection were partly behind the decision to adopt a metallic nose structure. "If we went for a composite structure we'd have to reinforce the area above the cockpit with titanium which is expensive," he says.

http://www.flightglobal.com/articles...-a380-style-nose-for-a350-xwb.html

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-29 00:43:48 and read 11893 times.

If you notice in your quote, he said it he found CFRP unsuitable for them because of the expense, not the suitability.

Here's an experiment you can try at home.

http://www.flug-revue.rotor.com/FRheft/FRHeft05/FRH0509/FR0509g.htm

Quote:
A lot of airlines initially had reservations about the fact that it is very difficult, compared with aluminium, to spot and repair structural damage in the CFRP skin of an 787 caused by vehicles on the ramp, known as “ramp rash”. Mike Bair dismisses these fears by saying, “Ramp rash was actually a concern of the customers, but CFRP is a lot stronger than aluminium.” Bair sent the airlines suitcases with fuselage pieces made out of aluminium and CFRP and a hammer. Whereas the aluminium dented, the CFRP apparently proved resilient and returned to its original shape. “If you cannot see any damage from a distance of 2 metres, it will last the life of the aircraft.” For other cases, Boeing envisages two types of “patchcraft”: the first variant dries within an hour and lasts until the next shop visit, the second variant on the other hand needs between six and 12 hours to dry but lasts an entire aircraft lifetime. Moreover, where structural damage is suspected, it is possible to check CFRP with ultrasound sensors applied to the outer skin. CFRP is also UV-resistant and the special primer can accommodate paint of any colour.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-29 01:05:02 and read 11872 times.



Quoting NCB (Reply 157):
Sorry but you don't know what you're talking about.
CFRP is very weak towards impact damage.

Here's some litterature for you:

Quote:
A350 XWB chief engineer Gordon McConnell says that the nose reprofile was made partly for improved aerodynamics and also to enable the overhead crew rest to be installed further forward and eliminate any encroachment in the passenger cabin.

He adds that strength requirements for birdstrike protection were partly behind the decision to adopt a metallic nose structure. "If we went for a composite structure we'd have to reinforce the area above the cockpit with titanium which is expensive," he says.

http://www.flightglobal.com/articles....html

Before you attack another person, perhaps you should get your facts correct. He is in CYB mode since Airbus can't do it. The reason they can't isn't techincal is origin, its in the cost/time area that is the hold up.

Boeing found it to not be an issue past wieght Vs resistance as they from the start were doing complex layups in full barrels. Airbus would have to develop all of that technology or buy it all starting behind Boeing who hoovered up patents and rights to patents for YEARS before the 787 was mentioned. So Airbus would need even MORE time and money to work around the patents either finding 2nd best methods or leapfrogging the current cutting edge. Both are unappealing choices.

They *might* be able to panel this section, only doing mating lines on complex curves is a slice of hell. The more sections they break it up into to simplify the overall construction the less appealing it is over convention construction.

last point they save HUGE money by doing a "cut and paste" of the A380 cockpit general design and not having to re-train all the engineers to work in new materials and methods. Boeing save a big pile using the 767 snout for the 777 even with a huge reworking of the interior cockpit section, there is no reason the reverse doesn't work for airbus by stuffing A380 cockpit guts in a new structure.

As to proof composites have plenty of impact resistance? ignoring the composite structures already used for areas on aircraft that see some nasty FOD at times, go look up what kind of abuse fiberglass hulled boats have endured in daily use. Most planes don't smash multi-ton hulls into multi-ton rocks with any frequency, and people on boats quickly notice when holes are made in the hull structure from said impacts.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: VirginFlyer
Posted 2009-05-29 01:07:38 and read 11868 times.



Quoting NCB (Reply 157):
Sorry but you don't know what you're talking about.
CFRP is very weak towards impact damage.

I'm not trying to be rude here, but do you reckon you might be able to qualify with what authority you are making that statement, other than the cited comment from Flight Global? I see at least two engineers (Tdscanuck and SEPilot) who seem to disagree with your assessment of the suitability of CFRP with respect to surviving impact damage. I'm not saying they're right because they're engineers, I'd just be keen to know whether you are making this analysis as a keen amateur or an interested professional.

Obviously there are some significant differences between the CFRP used on aircraft and that used on Formula 1 cars, but I don't suppose anyone has any information on how well those F1 cars stand up to being run across a gravel trap at high speed(as happens from time to time)? I'm not talking about them whacking into a wall - I don't think anyone expects them to stand up to that - but rather the extent to which the gravel being spat up causes damage to the carbon fibre used on the car.

V/F

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-29 01:56:53 and read 11829 times.



Quoting VirginFlyer (Reply 160):
Obviously there are some significant differences between the CFRP used on aircraft and that used on Formula 1 cars, but I don't suppose anyone has any information on how well those F1 cars stand up to being run across a gravel trap at high speed(as happens from time to time)? I'm not talking about them whacking into a wall - I don't think anyone expects them to stand up to that - but rather the extent to which the gravel being spat up causes damage to the carbon fibre used on the car.

Actually, they stand up to a high speed smack into a wall quite well. In fact, the roll bar and cockpit tub are made of CFRP precisely because of its impact resistance. The drivers lives depend on its durability. CFRP has been proven strong enough to replace steel roll cages.

If you take away the engine, about 85% of a forumla 1 car is CFRP.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-29 02:21:02 and read 11807 times.



Quoting JoeCanuck (Reply 161):
Actually, they stand up to a high speed smack into a wall quite well. In fact, the roll bar and cockpit tub are made of CFRP precisely because of its impact resistance. The drivers lives depend on its durability. CFRP has been proven strong enough to replace steel roll cages.

much of what you see on a modern CRFP racecar that breaks or colapses was designed to do so. Now sometimes it doesn't work that way and drivers have been hurt/killed, but lets face it 200mph closing speeds vs a stopped car isn't going to be where your engineering team is going to make injury proof. Its racing, not CRFP armored cars playing demo-derby. Thier focus is on managed deceleraton of the car in colision with the wall (which is rarely anywhere near even 100mph into the wall), letting "bad" things break off instead of staying attached to hammer the safety cell, minimizing penetration of the cell by outside objects, and control of the drivers body and head.

Hit a pole at 200 its going to knife a car in 1/2 unless its built like a battleship. Hit a parked car going 200 and one or both will get knifed in 1/2. ETC.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rwessel
Posted 2009-05-29 02:33:55 and read 11794 times.

Quoting JoeCanuck (Reply 161):
Actually, they stand up to a high speed smack into a wall quite well. In fact, the roll bar and cockpit tub are made of CFRP precisely because of its impact resistance. The drivers lives depend on its durability. CFRP has been proven strong enough to replace steel roll cages.

If you take away the engine, about 85% of a forumla 1 car is CFRP.

To expand on that a bit - F1 demonstrates the flexibility of composites a fair bit. While the tub is intended to stay intact under all reasonable conditions (and in practice seems to be doing a pretty good job at that), the body is *designed* to disintegrate in order to dissipate impact energy (also apparently working as intended). Basically a more dramatic form of the “crumple zones” found on most passenger cars.

Even when pushed beyond reasonable limits, the tubs have not shown any propensity to “shatter.” I remember one race a few years ago where a drive had a fairly head-on and very high speed impact with a wall. Enough that the front couple of feet of the tub was crushed (and the driver had severe foot and lower leg injuries). Beyond the point where the breaking/crushing carbon fiber dissipated enough energy, the remainder of the tub stayed intact. And the remainder of the driver stayed fairly intact as well.

Edit: I couldn't find the crash I was thinking about, but this one, involving Robert Kubica and the 2007 Canadian GP, is a pretty good example. He loses a front wing after a collision with another car, and gets launched over the grass and pretty much hits a concrete safety wall head on at 300km/h. While there's damage to the front of the tub - you can see his feet in the remains of the car - he doesn't even break any bones in his legs. Estimated impact was 75G.

http://www.youtube.com/watch?v=jBkYs97UfN4

[Edited 2009-05-29 03:10:05]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 03:44:07 and read 11719 times.



Quoting NCB (Reply 151):
Bleed-air is a simple system to maintain on modern airliners.

Oh, really? Those posters on this forum who have actually maintained airliners don't seem to think so.

Quoting NCB (Reply 151):
Only few people in the global aviation industry have the hands-on experience and research background to make these kind of calls.

I suppose you are one of them? What exactly are your qualifications?

Quoting NCB (Reply 157):

Quoting JoeCanuck (Reply 153):
So far, tests have indicated that CFRP is MORE resistant to fod damage.

Sorry but you don't know what you're talking about.
CFRP is very weak towards impact damage.

And you do? What are your qualifications?

Quoting Rwessel (Reply 163):

Edit: I couldn't find the crash I was thinking about, but this one, involving Robert Kubica and the 2007 Canadian GP, is a pretty good example. He loses a front wing after a collision with another car, and gets launched over the grass and pretty much hits a concrete safety wall head on at 300km/h. While there's damage to the front of the tub - you can see his feet in the remains of the car - he doesn't even break any bones in his legs. Estimated impact was 75G.

http://www.youtube.com/watch?v=jBkYs...7UfN4

Thanks for posting this. It was very instructive to watch. I am quite sure that if the car tub had been made out of any metal Kubica would now be dead. It is the best testimonial to the crashworthiness of CFRP that I have seen, and goes to my point that it is a much better, safer, and more durable material than aluminum for airliners. I believe that NCB and others are being misled by the fact that the failure mode for CFRP is totally different than for metal; metal distorts before it fails while CFRP disintegrates. What they miss is that the strength to weight ratio for CFRP is much, much higher than any metal, and CFRP will fail locally and not propagate that failure throughout the structure, whereas the distortion that metal (except for cast iron, which is hardly a suitable material for aircraft) experiences actually spreads the damage of an impact to a much larger area, and causes safety cages (such as on racecars) to collapse while the metal is still intact. This means that even though the structure might survive (in a matter of speaking), the occupant may not. There is also the factor that metal structures can crush and trap an occupant, whereas when CFRP fails it disintegrates, after which, if he/she survives, the occupant will not be trapped and can easily be extracted. This applies to aircraft as well; if the 737 that just crashed in Amsterdam had been CFRP I believe that the pilots would have survived.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-29 04:21:23 and read 11682 times.



Quoting JoeCanuck (Reply 158):
If you notice in your quote, he said it he found CFRP unsuitable for them because of the expense, not the suitability.

If you read well, it says that CFRP needs Titanium reinforcements because it can't cope with impact load on its own. Titanium is expensive.

Quoting SEPilot (Reply 164):
Oh, really? Those posters on this forum who have actually maintained airliners don't seem to think so.

Have you noticed keyword: "modern"?
B777, A380 for instance have simplified pneumatic systems that are at the same time very reliable and easy to maintain. Way better compared to a bunch of complicated electric systems that we'll find on the 787. Don't believe all that people say here about credentials.
I could say that I'm an astronaut and be a ground handler.

You can't compare F1 cars to aircraft. F1 cars do not have bridstrike or FOD requirements.
As said, CFRP has very good crash-resistance and can bear very high forces, but it has very poor FOD properties and will result in high repair frequency. Remember, we're discussing impact of light loads, not a 787 CFITting.

Quoting SEPilot (Reply 164):
And you do? What are your qualifications?

I will not discuss my personal or professional life on an internet forum with people I don't know.

I can't bear with all the non-sense that is being provided here by people who pretend to be industry insiders and even less with those who do not check the information before considering it a reality. In political terms it is called "propaganda".
I don't know close to everything about aircraft, but I discuss things that I can say with certainty, that without needing to put my "credentials" because I don't care if people believe me or not, it's not going to change the world.

Add tot that, I have heard alot of engineers and aviation college professors say alot of nonsense, so be aware of that too.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 05:24:20 and read 11607 times.



Quoting NCB (Reply 165):
Have you noticed keyword: "modern"?
B777, A380 for instance have simplified pneumatic systems that are at the same time very reliable and easy to maintain. Way better compared to a bunch of complicated electric systems that we'll find on the 787.

What about "modern" electrical systems? As others have pointed out, modern electrical systems are much more capable of self diagnosis than any other type of system. Also, my experience with electrical machine tool controls has given me a huge appreciation for their reliability. Electrical systems, provided they are either not exposed to or protected from harsh environments (such as road salt) are extraordinarily reliable. Just look at modern cars (and they are exposed to road salt.)

Quoting NCB (Reply 165):

You can't compare F1 cars to aircraft. F1 cars do not have bridstrike or FOD requirements.

No, F1 cars just have to cope with hitting concrete walls at up to 200mph. Somehow I think that that is a little more severe than bird strikes or stray rocks.

Quoting NCB (Reply 165):

I will not discuss my personal or professional life on an internet forum with people I don't know.

It is true that one can claim any credentials that they please. But by not providing any you have only your arguments to sustain themselves, and when they go contrary to what those of us who have actual experience in related fields have learned from our experience, they carry little weight. When someone says that they have done something, and their arguments show that they have knowledge and experience that backs that up, their arguments carry more weight. I have always backed up my arguments by stating what experience I have had to lead me to the conclusions I come to; you can disagree with my arguments or accept them, but at least you know how I got there. Your posts give nobody that ability; you make flat assertions with nothing on the record to back them up. Since your conclusions in general fly in the face of what I have learned in over 30 years of engineering experience, pardon me if I do not accept them.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Rheinwaldner
Posted 2009-05-29 05:52:06 and read 11577 times.



Quoting XT6Wagon (Reply 137):
Do a panel unsupported and you will be lucky if the only thing that happens is the new panel doesn't fit due to stress distortion.

But compared to joining fuselage barrels it surely is not as difficult.

Quoting Stitch (Reply 136):
I do not believe that an A350XWB is inherently easier to repair then a 787. I do not believe Airbus went with panels for maintenance, but instead for ease of assembly and a quicker EIS (thanks to not needing to develop new production and assembly techniques and train staff on them).

I believe Airbus went for panels because it is the future. True, there is no evidence that in the case of the A350 Airbus will realize cost, weight or maintenance savings compared to the barrels. I really would not be astonished if in 30 years the 787 would still be the only plane with a CFRP-barrel-fuselage.

Quoting Ikramerica (Reply 138):
You also have to look at the size of the 787 autoclaves, and that the A350 autoclaves would need to be even larger.

An autoclave with the size of 787 autoclaves probably is enough to produce at one step the panels for a whole fuselage. Because panels can be stacked and allow a much better usage of the volume.

Quoting Tdscanuck (Reply 142):
There is no reason, that I'm aware of, that existing composite repairs (which are considerably more capable than 3 in2) would not apply to the 787.

I really appreciate your know how. How big can a hole be to be repaired with those existing methods? I mean a real hole? How would integrated stringers and frames be handled?

Quoting Tdscanuck (Reply 142):
I'm not sure why you think that particular damage example would be a write off. It's repairable. Annoying, but repairable.

I don't think that it would be a write off. People only said (in arbitrary order):
a) CFRP structures can hardly be damaged at all
b) If there is a damage it can be patched
c) If it can not be patched the barrel can be replaced as easy as panel
d) Or the other camp says replacing a barrel means a WO

I consistently answered to those scenarios:

to a) See my last paragraph in this post below

to b) If the damage is as on the picture it may be repairable (I believe what you say) but a metal structure would surely be easier to repair. And there is another level of complication if the co-cured stringers of a CFRP skin get damaged too. In such situations the desire could arise that replacing the whole barrel or panel would be easier than it is and/or even feasible.

to c) Please don't tell me that splitting a whole plane in completely seperated fuselage parts is easier (or as easy) than dealing mostly with the surface. Joining barrels is core competence of the FAL. Imagine the section with the wing. Even the 787 has no barrel at the center fuselage. It shows the dilema that a aicraft fuselage is no ideal tube. It has holes everywhere. Loads are always concentrated at some spots. There are no continous load to be carried. This is true to such a degree that even the 787 at the central fuselage uses panels.

to d) That may not be the case for the panel design.

Quoting Tdscanuck (Reply 142):
Quoting Rheinwaldner (Reply 133):
I am quite sure that if ever a panel or a barrel has to be replaced the panel is easier.

If I had to plan the repair, I'd certainly rather do the barrel than the panel.

You once told different.

Quoting XT6Wagon (Reply 159):
Boeing found it to not be an issue past wieght Vs resistance as they from the start were doing complex layups in full barrels. Airbus would have to develop all of that technology or buy it all starting behind Boeing who hoovered up patents and rights to patents for YEARS before the 787 was mentioned. So Airbus would need even MORE time and money to work around the patents either finding 2nd best methods or leapfrogging the current cutting edge. Both are unappealing choices.

Pure propaganda. There is not the smallest hint that the A350 will not be more advanced in CFRP technology.

Quoting SEPilot (Reply 164):
What they miss is that the strength to weight ratio for CFRP is much, much higher than any metal, and CFRP will fail locally and not propagate that failure throughout the structure

That is right, but do you assume that this material property is used to make stronger vessels? I guarantee you they use it to make lighter vessels! The 787 is not stronger than the A330. It should be lighter. Thus all these "CFRP can withstand much higher forces"-statements are rubish. The manufacturers use that material to achieve a comparing strength with lighter parts. The skin would only be stronger if it would be so thick that the structure's weight would match the weight of a comparing metal structure. Which would result in unneeded excess weight. Only if you want to argue that the 787 has excess weight I would not contradict.
You can even argue that by the lower overall weights (see just A350 vs 777) the strength requirements get relaxed. This means that the CFRP structure does not even have to cope with comparing loads but with lowered. The A350 structure does not need to have the strength of the 777 structure at most places.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 07:38:57 and read 11481 times.



Quoting Rheinwaldner (Reply 167):
But compared to joining fuselage barrels it surely is not as difficult.

No, it will be MORE difficult, because the barrel construction means that when disconnected the fuselage parts of the barrel construction will retain their shape much better, and so it is simply a case of lining up the joints. When you take a panel the size of an A350 panel out of the fuselage it will be very, very difficult to get everything in alignment. It will also take far more disassembly, as EVERYTHING will have to be taken out of the fuselage adjacent to the panel being replaced, while (assuming that the barrel is pre-stuffed, which I'm sure it would be) the barrel fuselage only needs to be disassembled in the region of the joints.

Quoting Rheinwaldner (Reply 167):
I really would not be astonished if in 30 years the 787 would still be the only plane with a CFRP-barrel-fuselage.

I will make a flat prediction: Every new airliner that Boeing makes from now on will be barrel CFRP construction unless they go to a BWB. I expect that it is 50-50 whether Airbus makes another panel fuselage or whether they go barrels next time. I am quite sure that they went panels this time almost entirely because of time constraints. From an engineering perspective panels have only one advantage; they are easier to make.

Quoting Rheinwaldner (Reply 167):

That is right, but do you assume that this material property is used to make stronger vessels? I guarantee you they use it to make lighter vessels! The 787 is not stronger than the A330. It should be lighter. Thus all these "CFRP can withstand much higher forces"-statements are rubish.

Nobody knowingly makes an aircraft stronger than it has to be; that is not the point. What we are discussing is damage resistance and failure modes in CFRP vs. aluminum for the same strength. The whole point is to make it lighter, and the failure characteristics of CFRP happen to make it more damage resistant, and, I expect, more survivable in the event of a crash. Also, aluminum has to withstand fatigue, so it actually has to be stronger than the CFRP, because it does not fatigue. But it is absolutely true that a piece of CFRP that will safely carry a given load is more damage and impact resistant that a piece of aluminum that will safely carry the same load.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-29 07:39:51 and read 11492 times.



Quoting Rheinwaldner (Reply 167):
Quoting XT6Wagon (Reply 159):
Boeing found it to not be an issue past wieght Vs resistance as they from the start were doing complex layups in full barrels. Airbus would have to develop all of that technology or buy it all starting behind Boeing who hoovered up patents and rights to patents for YEARS before the 787 was mentioned. So Airbus would need even MORE time and money to work around the patents either finding 2nd best methods or leapfrogging the current cutting edge. Both are unappealing choices.

Pure propaganda. There is not the smallest hint that the A350 will not be more advanced in CFRP technology.

Indeed this is propaganda. Calling a newer plane 2nd best just because it uses different production techniques, which by itself are only a small factor in the use of modern technology in airliners, can only be called propaganda. And who says that the B787 is the current cutting edge in technology. It is already safe to assume (which does not make it a fact btw) that many systems on the A350 will be a generation newer and thus likely better than those on the B787. Nobody can make a statement like that (2nd best) and expect it to be true in the lifetime of airliner programs. See how the A330 has developed over time to be an immense success for Airbus just as the B777 did the same for Boeing.

Just like these endless discussions over which plane is better. In general plane X might be marginally better than airplane Y, but there could be quite an number of missions where mostly the "not as good as" regarded airplane still might beat its competitor to which it generally loses a comparison.

Since both the B787 and A350-XWB are highly successful and record breaking airliners regarding the number of sales, and both programs are still so young, especially that of the A350-XWB is, it is not even appropriate to talk about "winning" and "losing" or "better than" and "inferior to" (or "not as good as").

We will have to wait and see how these programs will unfold over time. And here I mean a timeframe of 10 years or so. Only then Boeing might be launching an improved B777 or a Y3 or so. They sure will not do so within the next 4-5 years imho. In that timeframe they should be working on the next NB which should be the successor of the incredibly successful B737 and B737-NG series.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Aerodog
Posted 2009-05-29 08:06:08 and read 11447 times.



Quoting EPA001 (Reply 169):
We will have to wait and see how these programs will unfold over time. And here I mean a timeframe of 10 years or so.

Very true and many of the comments made on this thread should be prefaced by two very important words, "In theory, ........."

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-29 08:11:42 and read 11444 times.



Quoting NCB (Reply 157):
CFRP is very weak towards impact damage.

There's simply no way to put this that you'll accept, I understand, but no, it's not.

Otherwise, they wouldn't use it for body armour specifically designed to prevent shrapnel penetration (which bears a lot of resemblance to FOD). Example:
http://www.globalsecurity.org/military/systems/ground/gauntlet.htm

Quoting Rheinwaldner (Reply 167):

But compared to joining fuselage barrels it surely is not as difficult.

I'm not sure about that. There's no real way to do a panel replacement without recreating some facsimlie of the original jigs to hold alignment while the panel is removed. Barrels, among other things, basically don't need a jig (you can see this clearly from photos of 787 final assembly). However, barrels are larger and harder to handle parts, so the logistics are certainly worse.

Quoting Rheinwaldner (Reply 167):

An autoclave with the size of 787 autoclaves probably is enough to produce at one step the panels for a whole fuselage. Because panels can be stacked and allow a much better usage of the volume.

This is the one huge, undeniable, and probably crucial (for Airbus) distinction between barrels and panels. Panels are far far easier to manufacture and transport.

Quoting Rheinwaldner (Reply 167):
How big can a hole be to be repaired with those existing methods? I mean a real hole? How would integrated stringers and frames be handled?

There are multiple types of repair you can do. For small holes (up to something like 3" x 3", I think, depending on the model) you could layup a scarf patch, or precure a patch and scarf it in. Larger than that you're probably guaranteed to use a precured patch. There's no real theoretical limit on that, but as the repair patch gets bigger it gets harder to build.

For stringers and frames, I suspect you'd install them as separate pieces (fastened) first, then apply the patch to that. Stringer and frame splices are a very typical repair today, so I suspect you'd go for the simplicity of doing multiple independant repairs rather than trying to recreate an integrated panel. Although a little heavier, that's more flexible and easier to do and, for the size of most holes, the weight delta won't be that large.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 08:49:52 and read 11395 times.

One aspect of the damage issue has not really been addressed, and that is the fact that when you damage an aluminum structure there can be hidden distortion far from the site of actual damage. In cars this is very common; one manifestation of this is the so-called "unibody twist" where a car is hit on one corner (and not necessarily all that hard) and the whole structure is twisted enough that it will always wear tires in unexpected ways but no visible distortion appears. Similar effects can happen to aircraft. I certainly have seen airplanes where damage appears to be localized but you can still see wrinkles far from the damage, especially on wings. CFRP does not do this at all; if it is damaged it will fracture, not bend. I think this will prove to be a tremendous advantage.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: VirginFlyer
Posted 2009-05-29 09:06:58 and read 11381 times.



Quoting NCB (Reply 165):
You can't compare F1 cars to aircraft. F1 cars do not have bridstrike or FOD requirements.
As said, CFRP has very good crash-resistance and can bear very high forces, but it has very poor FOD properties and will result in high repair frequency. Remember, we're discussing impact of light loads, not a 787 CFITting.

I believe when I raised the parallel with F1 cars, I specifically stated I wasn't talking about crash-resistance, but about the effect of gravel being flung up onto the structure:

Quoting VirginFlyer (Reply 160):
I don't suppose anyone has any information on how well those F1 cars stand up to being run across a gravel trap at high speed(as happens from time to time)? I'm not talking about them whacking into a wall - I don't think anyone expects them to stand up to that - but rather the extent to which the gravel being spat up causes damage to the carbon fibre used on the car.



Quoting NCB (Reply 165):
I will not discuss my personal or professional life on an internet forum with people I don't know.

And that is indeed your prerogative, but in the absence of presenting your own qualifications, surely it is reasonable to ask that if you are going to enter into a debate with those who have, you will cite authoritative studies on the issue.

Quoting NCB (Reply 165):
I don't care if people believe me or not, it's not going to change the world.

Add tot that, I have heard alot of engineers and aviation college professors say alot of nonsense, so be aware of that too.

You're definitely not wrong there. But in all honesty, in a debate on a technical matter where on one side there is a "Machine design engineer" and a "Flight Test Director", and on the other a "Management - Aviation", and there is a lack of substantive supporting material being put forward on the issue, who would you trust? Their qualifications don't make them right by any stretch of the imagination, but in the absence of substantive evidence to the contrary, it is very difficult to not agree with them. Again, I want to stress I am not having a go at you here or trying to be rude or disputing your level of knowledge on the matter, I'm just saying that objectively I'm finding it difficult to be swayed by your assertions thus far.

No this discussion is not going to change the world, but I'd like to think that we're all here to learn, and if the issue can't be effectively debated, then we're all poorer for it. As it has been presented, either the concern about FOD-resistance is genuine, in which case it deserves to be debated thoroughly, or it is an unsubstantiated fear of major change, in which case I feel we've wasted a lot of time, effort and bandwidth discussing a non-issue.

Anyway, I feel it is time I added something of value. I fear we may all be getting our knickers in a twist on the ramp rash issue when it may already be somewhat moot. There are a number of aircraft today which use CFRP in areas which are exposed to ramp activity. My attention was drawn to this by the following photograph, which illustrates quite nicely the areas using aluminium (polished) and the areas using composite (painted):


View Large View Medium
Click here for bigger photo!

Photo © Gabriel Widyna



I'm pretty sure the A320 family also uses CFRP for the wing-body fairing. Now, I know we're not quite comparing apples with apples here - the CFRP on the fairing is not to my knowledge part of the pressure vessel, nor is it an integrated barrel assembly, nor a large skin panel. However, is anyone aware of this area being damaged in normal operating conditions, and if so, what action had to be taken to repair it?

I did a quick search, and pulled up a number of documents, all of which referred back to this one: Low-Cost Composite Materials and Structures for Aircraft Applications, Paper presented at the RTO AVT Specialists’ Meeting on “Low Cost Composite Structures”,
held in Loen, Norway, 7-11 May 2001, and published in RTO-MP-069(II).


Quote:
Abstract
A survey of current applications of composite materials and structures in military, transport and
General Aviation aircraft is resented to assess the maturity of composites technology, and the
payoffs realized. The results of the survey show that performance requirements and the potential
to reduce life cycle costs for military aircraft and direct operating costs for transport aircraft are
the main reasons for the selection of composite materials for current aircraft applications. Initial
acquisition costs of composite airframe components are affected by high material costs and
complex certification tests which appear to discourage the widespread use of composite materials
for aircraft applications. Material suppliers have performed very well to date in developing resin
matrix and fiber systems for improved mechanical, durability and damage tolerance performance.
The next challenge for material suppliers is to reduce material costs and to develop materials that
are suitable for simplified and inexpensive manufacturing processes. The focus of airframe
manufacturers should be on the development of structural designs that reduce assembly costs by
the use of large-scale integration of airframe components with unitized structures and
manufacturing processes that minimize excessive manual labor.

Now, it is nearly a decade old now, but I'm going to go out on a limb and say that it is unlikely that the technology has become less reliable and more expensive in the time since it was published, and also it is probably not going to display too much in the way of bias to the 787 or A350 method due to predating them. It is well worth a read, and I thought I'd share a few salient points from it:

Quote:
The limiting factor in the widespread
application of these materials has been their high cost compared to conventional metals.



Quote:
The choice of composite materials in the F/A-18E/F was dictated by a need to reduce
weight and to improve strength, reliability and maintainability in an aircraft carrier environment.
The center and aft fuselage skins and other ancillary structure, such as the speed brake and dorsal
covers, are all-carbon/toughened- epoxy construction in the F/A-18E/F. Carbon fibers, such as
Hexcel’s IM7, with improved strength and stiffness properties are used in the wing and the tail
skins. Although composite materials in general are sensitive to impact damage, toughened
materials such as Fiberite’s 977-3 toughened epoxy system used on the F/A-18E/F have
successfully addressed this threat in operations.



Quote:
In the US, the most significant use of composites in commercial transports has been on the
Boeing 777. Composite structures make up 10 percent of the structural weight of the B-777.
Figure 8 shows the various composite structural elements used in the B-777. Corrosion and
fatigue resistance with weight savings and improved damage tolerance were the main drivers for
these applications.

Certainly that document would seem to suggest that ramp-rash damage of composite structures is not a major concern for large composite components, given the paper concludes:

Quote:
For increased future applications of composites in aircraft structures lowering their costs is
essential. The affordability lesson learned from a survey of US and European aircraft are as
follows:
1. Unitize and integrate multiple parts to reduce fabrication costs in the early stages of the
design process. One such example taken from the US Air Force Composites
Affordability Initiative (CAI) program is shown in Figure 11.
2. Simplify design and apply automation to reduce variable fabrication costs
• Replace lightly loaded integral stiffeners with Syncore sandwich construction
• Utilize fiber placement, performs, and other innovative material forms to reduce manual
lay-up
• Design for efficient manufacturing processes such as fiber placement and RTM

I must say I think this thread has drifted extraordinarily. Perhaps if we want to continue this discussion we might be better to start a new thread on it, possibly over in Tech/Ops since it really is a technical issue?

V/F

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-29 09:39:40 and read 11340 times.



Quoting EPA001 (Reply 169):
Indeed this is propaganda. Calling a newer plane 2nd best just because it uses different production techniques

Sorry but if you wish to attack the messenger use something valid instead of crying that I might somehow be slandering your almighty airbus.

From a technical standpoint the ENTIRE A350XWB is inferior. However the buisness of designing, making, and selling of Aircraft does NOT revolve around whats the bleedingedgiest thing in the sky. Them concordes took over the fleets in all the major airlines didn't they?

No. Airbus wisely chose to NOT invest billions in barrel technology just so they could make a CRFP nose section. I'm fairly sure that they look at the ledger and see a million a frame or more in lower costs with this. I'm sure they see lower risk from this.

Same thing with panels. Lower R&D cost. lower risk. Lower performance. To decide if its a good thing or a bad thing for Airbus you have to wieght the tradeoffs against each other. I personaly think its thier only choice given the need to respond to the 787 as quickly as possible. Don't forget 95% as good is more than good enough if its 90% the cost. The market place will quickly sort out if Airbus won or lost on this bet of cost Vs performance.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-29 09:43:10 and read 11324 times.

I think NCB is having a good time arguing silly points that he knows aren't valid to see how much he can bait everyone. Maybe it's time to stop humoring him?

Quoting XT6Wagon (Reply 162):
Thier focus is on managed deceleraton of the car in colision with the wall (which is rarely anywhere near even 100mph into the wall), letting "bad" things break off instead of staying attached to hammer the safety cell, minimizing penetration of the cell by outside objects, and control of the drivers body and head.

Just a note: Indy cars at the Indy 500 routinely hit the wall at over 200 mph in practice and in the race. Deaths are very, very rare, and come from spinal injuries due to G forces. The driver "tub" doesn't shatter and send shrapnel into the driver's body, either...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 09:59:15 and read 11363 times.



Quoting XT6Wagon (Reply 174):

Same thing with panels. Lower R&D cost. lower risk. Lower performance. To decide if its a good thing or a bad thing for Airbus you have to wieght the tradeoffs against each other. I personaly think its thier only choice given the need to respond to the 787 as quickly as possible.

Quite true; however I personally am convinced that the overwhelming factor was the time. Airbus needed to get a response to the 787 to market as soon as possible, and they not only would have had to develop their own way to do barrels but do it in a way that did not infringe on Boeing's patents. Without seeing a clear way to do it it is impossible to know how long it is going to take. I will add to your conclusion: having a plane 95% as good in 5 years will make more money than having one 105% as good in 10.

Quoting Ikramerica (Reply 175):
I think NCB is having a good time arguing silly points that he knows aren't valid to see how much he can bait everyone. Maybe it's time to stop humoring him?

Could be, but it's just too much fun. Big grin

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SeaBosDca
Posted 2009-05-29 10:07:35 and read 11353 times.

Quoting Ikramerica (Reply 175):
Maybe it's time to stop humoring him?

I'm all for it as long as it results in more great posts from Tom. I've learned a ton about materials from this thread.

Having had my own debate with NCB in which she stubbornly insisted that the 787's effective range was no longer than that of the 767, I do see a pattern...

[Edited 2009-05-29 10:10:48]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Zvezda
Posted 2009-05-29 10:23:50 and read 11338 times.

I'm not at all convinced that we'll ever see a panel or barrel replaced on an A350 or 787, respectively. Anything that can't be patched is probably a write-off. We might see an empennage replaced following a tail-strike. Replacing either a panel or a barrel would require custom tooling and be a major undertaking. It's difficult to see how either a panel or a barrel could be replaced in a month.

What is nearly certain is that any FOD, ramp-rash, or bird-strike damage can be patched -- if repair is even necessary -- whether barrels or panels are used to build a CFRP fuselage.

The idea that either Airbus or Boeing will develop future new airliners from metal rather than CFRP is nearly as far-fetched as the idea that they would go back to using wood and fabric, as airplanes were built 100 years ago. The cost, performance, and MX advantages of CFRP are overwhelming and will only improve with time relative to metals, especially for wide-bodies.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-29 10:36:45 and read 11309 times.



Quoting SeaBosDca (Reply 177):
I'm all for it as long as it results in more great posts from Tom. I've learned a ton about materials from this thread.

Me too. It was valuable for a while. But I think all the information has been given out at this point, and now it's just a CaptainX type debate. "Plane will crash because I say so." "No it won't." Tiresome.  Smile

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-29 10:37:47 and read 11337 times.



Quoting XT6Wagon (Reply 174):
From a technical standpoint the ENTIRE A350XWB is inferior.

 laughing 

Quoting XT6Wagon (Reply 174):
Same thing with panels. Lower R&D cost. lower risk. Lower performance.

I think the Airbus is more then just panels unlike Boeing and therefore inferior. Maybe the loads on the lower side and upperside and window areas of a fuselage are very different & therefor require different optimal solutions. Don't tell anybody..  shhh 



Quoting SEPilot (Reply 176):
Airbus needed to get a response to the 787 to market as soon as possible, and they not only would have had to develop their own way to do barrels but do it in a way that did not infringe on Boeing's patents.

- I far as I now they push out 8 A330s every month the 787 is delayed.
- Boeing used many patents that are not theirs. Composite fuselages is one of them.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 10:44:02 and read 11306 times.



Quoting Zvezda (Reply 178):
I'm not at all convinced that we'll ever see a panel or barrel replaced on an A350 or 787, respectively. Anything that can't be patched is probably a write-off. We might see an empennage replaced following a tail-strike. Replacing either a panel or a barrel would require custom tooling and be a major undertaking. It's difficult to see how either a panel or a barrel could be replaced in a month.

I tend to agree with you. About the only scenario that I can envision is a ground collision causing massive but localized damage. I cannot recall any incident like that happening (although I do recall that there was a DC-9 or MD-80 that was two airplanes pieced together) and have no expectation that it will. Like you, I suspect any accident requiring barrel or panel replacement will be a WO.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-29 10:45:37 and read 11312 times.



Quoting Keesje (Reply 180):
Boeing used many patents that are not theirs. Composite fuselages is one of them.

Boeing could have entered into exclusive licensing agreements with those patent-holders, however. It would have been a forward-looking thing for Boeing to do, not just to deny them to Airbus, but also Embraer, Bombardier, Sukhoi, Mitsubishi and ACAC.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-29 11:07:47 and read 11274 times.



Quoting Tdscanuck (Reply 171):
Otherwise, they wouldn't use it for body armour specifically designed to prevent shrapnel penetration (which bears a lot of resemblance to FOD). Example:
http://www.globalsecurity.org/milita...t.htm

Let's be clear, let's talk about apples and apples.
I have mentionned that CFRP shatters at impact. This is a reality that no one will dispute.
This shattering of the material dissipates the energy of the impact and provides extensive crash energy dissipation, which makes it an ideal material for anything that must provide good crash/impact energy absorpotion.

The issue I am bringing forward is that this easy chipping/shattering of the material that would prove to be a large issue for aircraft fuselages as these are frequently exposed to jumping stones and little birds at high speeds. Of course, the aircraft fuselage will survive all these little impacts but where metal structures tend to just bend for these kind of exposures and show a ding, CFRP will shatter that will cause loss of chips of the material and create a weak point. Where metal structures get dings (until manufacturer prescribed limits) , CFRP will get chipping of the material, requiring an immediate repair to avoid the chipped out areas to further develop into a crack with potential structural failure as a result.
You don't want to see what a CFRP fuselage would look like after a hailstrike...

This risk must not be underestimated and the XWB features a metal front for this very reason.

The XWB will also have issues where it uses CFRP on the fuselage...
I am all for a Titanium-fuselage  Wink

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Keesje
Posted 2009-05-29 11:09:56 and read 11293 times.



Quoting Stitch (Reply 182):
Boeing could have entered into exclusive licensing agreements with those patent-holders, however. It would have been a forward-looking thing for Boeing to do, not just to deny them to Airbus, but also Embraer, Bombardier, Sukhoi, Mitsubishi and ACAC.

That maybe possible. On the otherside the patent holders might be more interested to license to as many users as possible. Or be even forbidden to so, if e.g. the patent is developped under government supported R&D, as much Aerospace R&D is..

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: XT6Wagon
Posted 2009-05-29 11:10:52 and read 11272 times.



Quoting Stitch (Reply 182):
Boeing could have entered into exclusive licensing agreements with those patent-holders, however. It would have been a forward-looking thing for Boeing to do, not just to deny them to Airbus, but also Embraer, Bombardier, Sukhoi, Mitsubishi and ACAC.

I'm 99% sure that I've read they did just that for some of the key parts of thier barrel winding method. No reason for the patent holder not to. They can't run out and start making planes, and Boeing isn't going to run out and make racing sail boats.

Quoting Keesje (Reply 180):
I think the Airbus is more then just panels unlike Boeing and therefore inferior. Maybe the loads on the lower side and upperside and window areas of a fuselage are very different & therefor require different optimal solutions. Don't tell anybody..

Keesje, Why panels are inferior from an engineering standpoint is 2nd year engineering student stuff. Why airbus chose panels is a 2nd year economic students stuff. Which is better for Airbus is up for debate, and won't be proven till 20 years from now atleast.

Also perhaps you should enlightent me why a conventional aluminum nose on a CRFP skinned plane is better than a once peice CRFP nose that matches the methods used for making the rest of the plane?

If you can't see that the A350 program as it exists today isn't about making the best possible plane they can make, but the best possible plane for AIRLINES to buy and use, perhaps you should dial the fanboy tendancies down some.

Quoting SEPilot (Reply 176):
Quite true; however I personally am convinced that the overwhelming factor was the time

I agree 100%, with the factor that time is money. Extra years of R&D = extra years of expenses, extra years of lost sales, extra years of market share erosion, etc.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: PITIngres
Posted 2009-05-29 11:20:11 and read 11248 times.



Quoting NCB (Reply 183):
I have mentionned that CFRP shatters at impact. This is a reality that no one will dispute.

I'll dispute it. You are talking nonsense. "Shatter" assumes a low resistance to crack propagation, and composite as it is used in modern airliners is just the opposite. CRFP is not glass, and its properties are highly dependent on the specifics of its composition and layup. For a good tutorial on CFRP material properties, see some of Tom's recent posts.

Welcome to my DU (Dis-respected users) list.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-29 11:25:30 and read 11243 times.



Quoting XT6Wagon (Reply 185):
If you can't see that the A350 program as it exists today isn't about making the best possible plane they can make, but the best possible plane for AIRLINES to buy and use, perhaps you should dial the fanboy tendancies down some.

Well, it's about his ego, I guess. Because the "most advanced" is not always "the best" in the real world anyway. The market place has different priorities than engineers.

Airbus may have simply decided, from a cost standpoint, that the 787 was the largest plane practical for barrel construction, even if panel construction is slightly less "advanced" than the 787 approach.

Will people do a 180 when the eventual A320 replacement is made in 3 fuselage barrel pieces (front, center, rear)? Is it somehow possible that both barrel and panel designs are the "most advanced" when Airbus decides to use them?  Wink

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Zvezda
Posted 2009-05-29 11:25:51 and read 11253 times.



Quoting NCB (Reply 183):
I have mentionned that CFRP shatters at impact. This is a reality that no one will dispute.

I dispute that. The impact required to shatter the CFRP fuselage structures used by Airbus and Boeing would require an impact more powerful than typical FOD, ramprash, or birdstrikes. I'll concede that a mid-air collision of two airliners would involve CFRP shattering. Likewise, an incident like SQ6 at TPE would involve CFRP shattering.

Quoting NCB (Reply 183):
You don't want to see what a CFRP fuselage would look like after a hailstrike...

I would not expect a CFRP fuselage to suffer any damage at all from hailstones too small to penetrate an aluminium fuselage. In general, I think it's fair to say that, in most cases, an impact that would dent aluminium will not damage CFRP and an impact that would penetrate aluminium would require a CFRP patch.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-29 11:37:47 and read 11221 times.

CFRP does indeed shatter on impact.

So does Aluminum. Even Titanium will shatter under impact.

However, none of them shatters at any impact, just at certain impacts. And there are composites that are stronger then titanium, to say nothing of aluminum.

[Edited 2009-05-29 11:44:14]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 11:42:02 and read 11219 times.



Quoting Keesje (Reply 180):

- I far as I now they push out 8 A330s every month the 787 is delayed.
- Boeing used many patents that are not theirs. Composite fuselages is one of them.

At the time Airbus decided which way to go on the A350XWB it was not known that the 787 would have so many problems. If Airbus had known that they might have made a different decision. And as Stitch rightly says, I'm quite sure that Boeing has locked up the rights to all of the patents they are using, be they theirs or not. All it takes is being first in line with the biggest wallet, which I'm sure they were.

Quoting NCB (Reply 183):
I have mentionned that CFRP shatters at impact. This is a reality that no one will dispute.

So does hardened steel. What is at issue is how much impact it will withstand for a given strength. The fact remains as used in aircraft fuselages it will withstand without damage far greater impacts than will aluminum, and when it does shatter it does so quite locally and can readily be repaired.

Quoting NCB (Reply 183):

The issue I am bringing forward is that this easy chipping/shattering of the material that would prove to be a large issue for aircraft fuselages as these are frequently exposed to jumping stones and little birds at high speeds. Of course, the aircraft fuselage will survive all these little impacts but where metal structures tend to just bend for these kind of exposures and show a ding, CFRP will shatter that will cause loss of chips of the material and create a weak point.

Again, CFRP of the thickness used for the aircraft can withstand without damage far greater impacts than can aluminum. One thing I think you are overlooking; metal structures are subject to cracks propagating, known as notch sensitivity. CFRP is almost completely immune to notch sensitivity; and hence little dings actually are even less important than they are in metal. Just because CFRP shatters when it yields does not mean that it will do it when you look at it crosseyed.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-29 11:42:45 and read 11221 times.

I attended the Formula One race in Monaco last weekend as a guest of one of the teams. And I've been to many F1 races as the guest of many F1 teams over the years.

I've held a CFRP suspension piece. It's a few mills thick, yet it could easily handle my ~130kg of weight pressing down on it when it was oriented in the "direction of strength" of the fibers and epoxies. The engineer I spoke to said it could take loads scores of times that and does during a race weekend. And yet, I could snap it in half when I stressed it in a way it wasn't designed to handle loads and Lewis Hamilton discovered that the hard-way during Qualifying.

Now F1 could have designed that suspension piece to take loads in other dimensions and survive. But that adds mass which adds weight - and F1 is an industry that will spend €10000 to save 10 grams of weight.

Aerospace is also an industry where weight matters, but that is tempered by the need to be safer then Formula One and working with much larger structures.

And yet, when I saw a mechanic drop a spanner on the engine cowl, it didn't punch through. It didn't dent it. It didn't even scratch the paint. And this cover was a mil or two thick and I could swing the entire thing over my head one-handed, it was so light.

CFRP panels and barrels on commercial airplanes will be designed to resist stresses and impacts just like the CFRP panels on a Formula One car will. Put enough impact energy in it, and it will fail, but so will a metal if you load it beyond it's limits.

And remember, aluminum is generally not as strong as steel which is generally not as strong as composites. True, different aluminum and steel alloys have different properties, but so do composites.


Oh, and before they made suspension pieces out of CFRP, they used to make them out of titanium, because it was strong as steel, but lighter.

Know why they went to CFRP?

It was stronger.

[Edited 2009-05-29 11:54:14]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-29 12:29:14 and read 11134 times.



Quoting Stitch (Reply 191):
Know why they went to CFRP?

It was stronger.

Excellent summation. It should be the end of the story.  praise   checkeredflag 

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JayinKitsap
Posted 2009-05-29 13:08:33 and read 11061 times.



Quoting SEPilot (Reply 190):
Just because CFRP shatters when it yields does not mean that it will do it when you look at it crosseyed.

A minor correction - CFRP materials usually do not have a yield point, it should be "when it fails".

In my structural design business I design in wood, steel, aluminum, concrete, and fiberglass. Each element can often be made of a wide variety of materials, with different advantages. Look at garden tools, how many tool handles are now plastic or composite vs the thin steel tube or wood of the past.

In filament wound fiberglass tanks which surprisingly have very similar stress conditions as an aircraft hull (internal pressure, flexure in the axial direction, localized and general external pressure) fiberglass is an excellent material. We go to great lengths to make full barrels, I have seen field winding of a 80 foot diameter FRP tank before. However, I have also designed tanks that are knocked down into segments. It is very doable, but there is more material to compensate for the joint efficiency and lap.

Composites being lighter allows for a thicker skin for a given weight. Out of plane bending is a big issue in thin shells. As the Moment of Inertia is a 4th power function of thickness, and the Section Modulus is a 3rd power function even minor increases in thickness make huge differences in strength. For example the difference between 0.10" and 0.12" is 172% as strong for the same stress level.

Metals typically exhibit a yield strength with a near flat stress strain curve at that point allowing a lot of energy absorbtion. Fiber - Resin composites generally do not exhibit yield behavior, failure begins with either fiber rupture or bond loss and can be quite rapid. However metals in compression have a very sudden buckling threshold which can occur at surprisingly low stress levels compared to yield. A steel sheet 0.10" with a E of 29,000 KSI would be limited to a 5" span in compression with a maximum stress of about 3.5 KSI compared with a yield of 50 KSI. This compression buckling is usually the controlling issue in metal shells, less so in CFRP.

There is no technical reason why a barrel couldn't be repaired with a panel. There would be the same type of joint between the repair panel and original shell whether a barrel or panel structure. The size and cost to design and produce the repair patch should be similar whether a barrel or panel structure. A barrel structure would allow the removal of the nose or tail barrel for replacement at a far lower cost than a writeoff. Basically it would require the purchase of a full prestuffed barrel section and have it flown two the site of the repairs. Not cheap but clearly less than a writeoff.

The size of the needed mandrels and autoclaves sufficiently large to do a 12 across 2 aisle plane seem doable. I would think that any barrels larger than the 787 would all need to be produced at the final assembly site or transport by sea.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-29 14:33:50 and read 11001 times.



Quoting Zvezda (Reply 188):
I dispute that. The impact required to shatter the CFRP fuselage structures used by Airbus and Boeing would require an impact more powerful than typical FOD, ramprash, or birdstrikes. I'll concede that a mid-air collision of two airliners would involve CFRP shattering. Likewise, an incident like SQ6 at TPE would involve CFRP shattering.

Check the following out, about aviation grade CFRP, by researchers.

Quote:
1. INTRODUCTION
Composite structural materials in a flight aircraft, which play an important role on the lifetime, will be subjected to several service environments. One of the dominated factors limited the use of composite materials is their poor damage tolerance because of the weak resistance to impact damage and reduced compression strength in the presence of impact damage. The compression after impact (CAI) test, which reflect the damage tolerance will be a valid evaluation method for the realistic application of these material.

Short et al.[1] have been carried out the impact tests of CFRP panels under low velocity impact.
Impact damage occurred in a form of delamination through the thickness of CFRP panels. Compressive strength reduction due to impact was similar to that of delamination within the same area of damage.

Written by:

Quote:

H.K.Yoon1, J.H.Lee2, Y.H.Park2, and J.S.Park3

1 Division of Mechanical - Information and Industrial Engineering, Dong-Eui University, 24,
Gaya, Busanjin-Gu, Busan, 614-714, Korea
2 Graduate School of Mechanical Engineering, Dong-Eui University, 24,Gaya, Busanjin-Gu
Busan, 614-714, Korea
3 Researcher of Institute of Advanced Energy, Kyoto University, Gokasho, Uji, Kyoto, 611-
0011, Japan

http://www.scientific.net/KEM.261-263.295

PS: shattering is delamination for those who don't understand what it means.

Read the document before you reply with things that don't make sense.


Throught this document and the Flightglobal article mentionning XWB program chief, the point has been made and I m aware that those who proudly swing the flag of engineers on airliners.net can not know everything. I don't know everything and I learn alot around here too.
Worse, I'd say that most engineers tend to learn things from their own perspective, and without the experience at hand, tend to defend their presumptions to death (well at least that is the beauty of science, the attempt to explain the reality)

Composite is a special field guys, nothing to worry about. You bettter go to bed knowing you learned something today rather than be stubborn and try to prove things using the theory of Einstein.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: JoeCanuck
Posted 2009-05-29 14:57:04 and read 10980 times.



Quoting NCB (Reply 194):
Composite is a special field guys, nothing to worry about. You bettter go to bed knowing you learned something today rather than be stubborn and try to prove things using the theory of Einstein.

As it turns out, both Boeing and Airbus are specialists in composite technology, which is why they've chosen to extensively use these materials over the past few decades.

It is they who are stubbornly continuing on with the use of composites. Their belief in composites is so persistent that they are, in fact, betting the future of their respective companies on the suitability of composites in aircraft.

Since these two very successful companies are experts in both aircraft design and composites, I will continue to defer to their expertise on the subjects.

If you disagree, you'll have to take it up with them. Better do it soon, though, because in the next few years, expect a rash of plastic planes take to the skies.

I, for one, will go to bed confident that the airplanes I will undoubtedly fly on were designed by experts, not amateurs.

That's what I learned.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Ikramerica
Posted 2009-05-29 17:03:50 and read 10874 times.



Quoting NCB (Reply 194):
Read the document before you reply with things that don't make sense.

I know I said that I would stop arguing with you, but because you are now using scientific studies to spread propoganda, it must be countered.

You are aware that this document involves SANDWICH style CFRP construction (says so right in the title) and the 787 barrels are NOT this kind of CFRP? There are plenty of parts of the 787 that are this type (wingtips, trailing edge wing surfaces, engine coverings, etc.), but not the pressure vessel, the tail cone, the wings, or the stabilizers.

For the most stressed bits, they are using LAMINATE construction, and no they are not the same thing. They are two different processes.

Might it be that Boeing didn't want to use the less expensive SANDWICH CFRP for the very reasons you cite other than for easily replaceable parts, but you are just not informed enough to know the difference?

Okay, back to ignoring your Chicken Little act...

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-29 17:54:02 and read 10824 times.



Quoting XT6Wagon (Reply 174):
From a technical standpoint the ENTIRE A350XWB is inferior

 rotfl   rotfl   rotfl  I am very sorry that such a limited view on judiging an aircraft design (which is not even completely finalized yet) can actually exist. But since you state this we all should believe this? Nobody will seriously believe such un unfounded and unqualified statement.  rotfl   rotfl   rotfl 

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: EPA001
Posted 2009-05-29 18:04:01 and read 10806 times.



Quoting XT6Wagon (Reply 174):
your almighty airbus

Such a bold ans also unfounded point of view was never posted by me. Please do not suggest that I said so and keep your preference as much as possible out of the discussion and try to stay with the facts.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: PlanesNTrains
Posted 2009-05-29 18:06:16 and read 10803 times.



Quoting Ikramerica (Reply 196):
I know I said that I would stop arguing with you, but because you are now using scientific studies to spread propoganda, it must be countered.

You are aware that this document involves SANDWICH style CFRP construction (says so right in the title) and the 787 barrels are NOT this kind of CFRP? There are plenty of parts of the 787 that are this type (wingtips, trailing edge wing surfaces, engine coverings, etc.), but not the pressure vessel, the tail cone, the wings, or the stabilizers.

For the most stressed bits, they are using LAMINATE construction, and no they are not the same thing. They are two different processes.

Might it be that Boeing didn't want to use the less expensive SANDWICH CFRP for the very reasons you cite other than for easily replaceable parts, but you are just not informed enough to know the difference?

Okay, back to ignoring your Chicken Little act...

Brilliant. I have tears of happiness.  Smile

-Dave

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-29 18:09:56 and read 10806 times.



Quoting Ikramerica (Reply 196):

It seems clear that トロール do not understand materials science, do you not agree?

Fortunately, we have members here who do and I think our audience is intelligent enough to figure out the "wheat" from the "chaff".

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-30 03:00:58 and read 10638 times.



Quoting Ikramerica (Reply 196):
You are aware that this document involves SANDWICH style CFRP construction (says so right in the title) and the 787 barrels are NOT this kind of CFRP?

Read it well, (and not just the title).
It's a study of a sandwichpanel structure with Aluminum and CFRP compared to a regular laminate CFRP structure.

Quote:
Carbon fiber reinforced aluminum layer laminate (CARALL), which were consisted of various numbers of CFRP prepregs, adhesive films and aluminum sheets, were fabricated by an autoclave. Impact damage behaviors of carbon fiber reinforced plastic (CFRP) and CARALL were investigated. The impact damage resistance of CARALL was significantly higher than that of CFRP

A and B of course know what they are doing.
A made the nose metallic to limit consequences but made the body CFRP because they had to under pressure of customers who were all going for the 787, remember they were very reluctant about putting CFRP on the A350 MKI.
B chose for full CFRP from the start, more for the sensation than for efficiency. They were more worried about selling and building it than its actual performance in service.

The good side of it is that airlines will have to hire alot of CFRP repairmen, creating new jobs. I won't be surprised to read articles around 2012 about airlines complaining about the high repair cost of minor superficial CFRP damages.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: WithaK
Posted 2009-05-30 04:17:24 and read 10594 times.



Quoting NCB (Reply 194):
PS: shattering is delamination for those who don't understand what it means.

I'm confused about shattering and delamination being the same thing. Shattering would imply that pieces of the structure detach from the rest of the structure or the entire structure itself separates into smaller pieces. A delamination is when the layers of a composite laminate separate which can occur during an impact event. Both shattering and delamination are local failures of a composite structure but they are not one and the same.

Kris

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Tdscanuck
Posted 2009-05-30 07:19:57 and read 10464 times.



Quoting NCB (Reply 201):
I won't be surprised to read articles around 2012 about airlines complaining about the high repair cost of minor superficial CFRP damages.

They don't complain about it now, and we've got CFRP running around all over the place in ramp-rash prone areas (nacelles, fixed and moveable leading and trailing edges, wing-body fairings). Fuselage laminates would be considerably stronger than any of those parts, hence less damage prone, not more.

Quoting WithaK (Reply 202):
I'm confused about shattering and delamination being the same thing.

You're right, they're not the same thing in any way.

Tom.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-30 08:14:38 and read 10424 times.



Quoting Tdscanuck (Reply 203):
They don't complain about it now, and we've got CFRP running around all over the place in ramp-rash prone areas (nacelles, fixed and moveable leading and trailing edges, wing-body fairings). Fuselage laminates would be considerably stronger than any of those parts, hence less damage prone, not more.

LH had setup LH Technics Tulsa which is specialised in composite part repairs mentionned by you because it's a very lucrative business. Not surprisingly, their motto is "repairing instead of scrapping".

All the parts by you mentionned are maintenance nightmares for airlines.

A little crack and soon enough it becomes a scrap or repair question.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: SEPilot
Posted 2009-05-30 11:14:42 and read 10288 times.



Quoting NCB (Reply 201):
B chose for full CFRP from the start, more for the sensation than for efficiency. They were more worried about selling and building it than its actual performance in service.

I have a little more confidence in Boeing than that. They have seen first hand how one plane with a questionable reputation (the DC-10) can ruin a manufacturer. I doubt that they want a repeat.

Quoting NCB (Reply 201):
The good side of it is that airlines will have to hire alot of CFRP repairmen, creating new jobs. I won't be surprised to read articles around 2012 about airlines complaining about the high repair cost of minor superficial CFRP damages.

As TDSCanuck says, they have a lot of it to repair (or not) right now. They certainly have enough that they would not have flocked to the 787 and pressured Airbus to follow suit if they were concerned about repairing CFRP.

Quoting NCB (Reply 204):
A little crack and soon enough it becomes a scrap or repair question.

Now you are clearly talking nonsense. One of the huge advantages of CFRP is that cracks DO NOT propagate.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: PlanesNTrains
Posted 2009-05-30 13:42:13 and read 10196 times.

It's starting to feel like one of those threads where you are baited into making statements that are then twisted into being anti-Airbus or pro-Boeing.

NCB, what did Boeing do to deserve this?

Quoting Nomadd22 (Reply 70):
Might as well have a CaptainX fanclub reunion.

Exactly.

-Dave

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NZdsgnr
Posted 2009-05-30 13:54:40 and read 10192 times.

I'm sorry guys but rather than arguing with NCB, you should be bowing and worshipping this absolute goddess of knowledge, no matter whether she discloses her background or not.

She is always going to be right,

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: NCB
Posted 2009-05-30 13:56:43 and read 10193 times.



Quoting SEPilot (Reply 205):
Now you are clearly talking nonsense. One of the huge advantages of CFRP is that cracks DO NOT propagate.

Cracks propagate through CFRP under both static and dynamic loads.
How could it otherwise reach structural failure?
If only that were true, it was enough to have a whole airplane built of baked CFRP sheets with microscopic thickness and it would be possible to build a 20 ton, everlasting A380.

I must admit that it's discouraging to talk to people who are most interested in building a reputation on an internet forum rather than to exchange ideas and knowledge which is its actual purpose.

I love Keesje for that, he is an excellent Dutchman, shares ideas, gives his opinions through arguments (not through insults or through pointless provocation) and is very knowledgeable. I don't always agree with him but his arguments are mature, make sense and are founded.

I'm European, travelling the world but residing in Japan, working for a major aviation company. There are 3 generations of aviation professionals in my family, I' m born through aviation, living through aviation.
I think that many people are mislead by the Japanese flag next to my username.
It's sad to see that people tend to attack people preassume to be from different ethnies than themselves as soon as these come forward with information of advanced nature.
One thing is sure though, Japan is way more advanced than the Western world on composites. First-year students of technical engineering colleges get in-depth lectures about composites around here.

Worse yet, most Japanese kids can already read and count before they start going to school at age 5-6. At age 6-7 they learn at school what they teach in Europe at age 12-13.
Don't be mislead by UN's misleading education index. The level of education is so high that many people don't make it into the colleges, and those who do must pay astronomical amounts of money. Japan also doesn't get many inbound exchange students unlike the US, Australia, New Zealand and sees alot of students leave abroad, lowering the education index for Japan and increasing that of other countries.

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Stitch
Posted 2009-05-30 14:15:45 and read 10175 times.

Quoting NCB (Reply 208):
One thing is sure though, Japan is way more advanced than the Western world on composites. First-year students of technical engineering colleges get in-depth lectures about composites around here.

Considering Japanese suppliers (Toray Industries) are providing the composites to the 787 subs, I am surprised you are so convinced that the plane will be so fragile.

Quoting BusinessWeek in June of 2005:
Toray Industries Inc., the Japanese supplier of Boeing's carbon-fiber tape, impregnates the fibers with a proprietary mixture: The epoxy that provides strength and hardness is surrounded by a polymer with a different density. This combination makes the surface less prone to impact damage -- and if damage does occur, it prevents cracks from spreading. Because of this breakthrough, "I will be sleeping soundly whenever I take off on a composite airplane," says Washington University professor Seferis.


[Edited 2009-05-30 14:18:16]

Topic: RE: "Boeing Could Offer T7 Replacement"
Username: Srbmod
Posted 2009-05-30 14:29:29 and read 10166 times.

This thread is beginning to stray into Airbus v. Boeing territory, and as a result, it is now locked.


The messages in this discussion express the views of the author of the message, not necessarily the views of Airliners.net or any entity associated with Airliners.net.

Copyright © Lundgren Aerospace. All rights reserved.
http://www.airliners.net/