philidor
in service - 6 years
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Post by philidor on Jun 16, 2015 22:34:45 GMT 1
AFAIK the 787-8 is the baseline model. It is! Yet, the thrust requirement was not based on the 788 needs - the engines perfectly fit the 789, and even the 787-10 uses the same engine as the rest of the family. As a consequence, the 787-8 has somewhat too large and too heavy engines, generating much weight and drag -- like a shrink.
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s543
in service - 2 years
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Post by s543 on Jun 16, 2015 22:49:52 GMT 1
As a consequence, the 787 has somewhat too large and too heavy engines, generating much weight and drag -- like a shrink. Way not enough for the Emirates
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philidor
in service - 6 years
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Post by philidor on Jun 16, 2015 23:22:08 GMT 1
As a consequence, the 787 has somewhat too large and too heavy engines, generating much weight and drag -- like a shrink. Way not enough for the Emirates I edited my post for clarification. The 787-8 is the only variant with somewhat too large and heavy engines. The 787-9 has an engine perfectly matching the airframe, while the 787-10 lacks power in certain conditions, as pointed out by Tim Clark. Some operators may also find it has insufficient payload/range.
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XWB
in service - 11 years
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Post by XWB on Jun 16, 2015 23:58:01 GMT 1
That's because Boeing made significant changes to the 787-9 frame.
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Baroque
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Post by Baroque on Jun 17, 2015 4:47:12 GMT 1
RE: the 787 stretch and double stretch, this Flightglobal article best describes what's going on and I would very much agree with their views on this regard here (well worth a read I would say). To summarise: The 787-8 was envisioned as the baseline model from the start with the -9 being the planned stretch, and the -10 being the double stretch. However, Boeing added many improvements during the -9 development that it lost a bit of commonality with the -8 while adding performance and range. The -9 will have more commonality with the -10 than it has to the -8, so the -9 sort of becomes a "makeshift baseline model" for the -10 due to the improvements. In theory, Boeing can roll out most of the same improvements into the -8 as well but is reluctant to do some on grounds of cost and the -8's market appeal. Now, I see the A350 as not being far off from the above situation. The -900 is the baseline for sure. But the next larger sibling sports design improvements to enhance performance and range as well like the extended wing trailing edge, triple bogey MLGs and more powerful engines. If Airbus can do a simple stretch of the -1000, the -1100 will be sort of in the same league as the 787-10, IMO. Might be too early to talk of re-engining these things, but think about what that would do to them. Will they become the equivalent to the 777-8x and 777-9x but much lighter?
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s543
in service - 2 years
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Post by s543 on Jun 17, 2015 8:03:39 GMT 1
Now, I see the A350 as not being far off from the above situation. The -900 is the baseline for sure. But the next larger sibling sports design improvements to enhance performance and range as well like the extended wing trailing edge, triple bogey MLGs and more powerful engines. If Airbus can do a simple stretch of the -1000, the -1100 will be sort of in the same league as the 787-10, IMO. But I do believe there is a BIG reason for AB to learn the lesson and once more the improvements project into - IF EVER - much later made 1100. All depends on the situation, I do not believe that 1100 is on the table before 2019 and than......
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philidor
in service - 6 years
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Post by philidor on Jun 17, 2015 9:46:48 GMT 1
Baroque, in my opinion Airbus' and Boeing's respective choices have been different. Boeing has preserved engine commonality, to the point of launching the 787-10 with a less-than-optimal payload/range. Airbus on the other hand based the A350-1000 re-design on a new more powerful engine, paying little attention to Tim Clark's protests.
In my opinion, these are logical decisions since the A350 family competes with both the 787 and 777 families.
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Baroque
in service - 2 years
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Post by Baroque on Jun 18, 2015 14:26:10 GMT 1
Eh... I messed up a post of mine that ended up getting deleted by accident . So just to bring back what was in it... I agree with s543 that it is hard to envision the potential -1100 coming online before 2019 given how the -1000 is yet to come together. I'm also intrigued by the comment that the -1100 may have a range of more than 7,900 Nm with engine and wing improvements according to this post by addasih. Coupled with the A380neo stretch, it looks like Airbus is moving the A380 still further away from the 777X and the A350 deeper into the 777X's territory.
Now Leeham has some extracts from an interview with Leahy who says that it could have about 40 more seats and might have a bigger fan for the engine. So it looks to be more than just a simple stretch of the -1000. (And a nudge to Taliesin, if you would like to chime in )
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Taliesin
Final Assembly Line stage 1
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Post by Taliesin on Jun 18, 2015 18:06:02 GMT 1
On the subject of your post being lost, try the Firefox plugin "Lazarus", it saves a certain number of texts for any website, you would have probably been able to recover your post through it. Also great in case of a browser crash I'm a little skeptical when it comes to the range of 7900nm for the A350-1100. From what I gather, that's also the maximum range of the A350-1000, so that would mean additional modifications to the wing and engines as well as a higher MTOW. IMO, it would make more sense to aim for greater commonality between the two versions and make either one a simple shrink or stretch. The other version would profit from the improvements, too. Aim for the best -1100 you can build and make the -1000 a simple shrink maybe? If you don't, you end up with 3 heavily modified airframes with very little commonality both in terms of airframe as well as power plant. On the subject of performance and range, I never understood why manufacturers like to give the maximum passenger range for all airplanes. It's an absolutely meaningless figure in the real world. The interesting number is the range at or near MZFW. The A350-1000 is projected to have a range of some 5600-6000nm at MZFW. I think the -1100 needs a range of about 6000nm, so it can do LHR-SIN and reach all other important asian destinations, too. If such a -1100 actually turns out to be feasible, I think Airbus would be in a position to put a lot of pressure on the 777X both from below and from above with an A380NEO.
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Post by stealthmanbob on Jun 18, 2015 18:35:57 GMT 1
On the subject of your post being lost, try the Firefox plugin "Lazarus", it saves a certain number of texts for any website, you would have probably been able to recover your post through it. Also great in case of a browser crash I'm a little skeptical when it comes to the range of 7900nm for the A350-1100. From what I gather, that's also the maximum range of the A350-1000, so that would mean additional modifications to the wing and engines as well as a higher MTOW. IMO, it would make more sense to aim for greater commonality between the two versions and make either one a simple shrink or stretch. The other version would profit from the improvements, too. Aim for the best -1100 you can build and make the -1000 a simple shrink maybe? If you don't, you end up with 3 heavily modified airframes with very little commonality both in terms of airframe as well as power plant. On the subject of performance and range, I never understood why manufacturers like to give the maximum passenger range for all airplanes. It's an absolutely meaningless figure in the real world. The interesting number is the range at or near MZFW. The A350-1000 is projected to have a range of some 5600-6000nm at MZFW. I think the -1100 needs a range of about 6000nm, so it can do LHR-SIN and reach all other important asian destinations, too. If such a -1100 actually turns out to be feasible, I think Airbus would be in a position to put a lot of pressure on the 777X both from below and from above with an A380NEO. as the A350-1000 is coming first I don't think it can Be a shrink of the -1100, which they have not committed to yet ? The -1100 would be heavier any way as it would be longer, but that also gives you extra space for another fuel tank to get the range you want ? the wings are over engineered I think like the A380s ?
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