Quoting Revelation (Reply 47): Given its scope of changes, A380X still has exposure to such risks, IMHO.

True. But can you grant me that it's a little less risky in addition to being less costly?

Quoting Revelation (Reply 47): I'm not following.

I was referring to my reframing of the issue: In a world where the A380 didn't exist, should somebody launch a VLA? Because I believe the answer would be "yes," any carryover from previous production is gravy. I reframe because I believe that (1) CEO will make no meaningful profit from here on out and (2) NEO will make no meaningful profit beyond development cost. On those premises the existence of the A380 is a nonfactor from an OEM profit-maximizing perspective. You might not share any of my premises (and reasonably so); perhaps the point wasn't put well to you.

Quoting Revelation (Reply 45): I think the big issue is that operators are not finding routes for the A380.

Some airlines are certainly not suitable A380 customers (MH, TG), but others I think have been very cautious (BA, CX) about an aircraft that could suit them quite well. Obviously if there is a significant downturn in air travel they're highly exposed, but they're also avoiding potential upside.

Quoting parapente (Reply 44): And how about it just looks stubby'

It looks that way to me. Its wing is gigantic. Whenever I fly her I try my hardest to get the front 10 rows just so my view does not get blocked by that wing. I think the A389 mock ups look great.

Quoting KD5MDK (Reply 51): others I think have been very cautious (BA, CX) about an aircraft that could suit them quite well. Obviously if there is a significant downturn in air travel they're highly exposed, but they're also avoiding potential upside.

Do you mean LH instead of CX? I think CX has been very cautious in regard to the A380   I think they could have made it work but I do not see an order any time soon.

tortugamon

Quoting matt6461 (Reply 48): One of airline executive's most frequently-cited dings against upgauging, whether 777X or A380, is yield dilution. If a plane carries X more seats than previous equipment's Y, an airline must, by definition, sell X more cheaply than Y. All previous seats were sold to the "highest bidders," as computed by yield management programs. X will be those who bid too low on Y. Thus yield declines.

Or in the case of MAN go from having a 2 class 77W to getting the A380 with F introduced at MAN for the 1st time and enlaged J cabin. That a 2 daily MAN 2 class 77W was more profitable than LGW's 3 daily service with F class is one of life's little mysteries as the wisdom is MAN = low yield.

Quoting david_itl (Reply 53):

A mystery indeed. One theory is that, while MAN is low yield for airlines in general, perhaps London is relatively lower-yield for EK. To where can one travel on EK from London that there is no direct flight? Australia/NZ of course but Aussies can't fill 6 daily A380's and all the other Kangaroo traffic, right? I wonder if EK is really scraping the bottom of the yield barrel in London. Of course that barrel's bottom may be gold compared to MAN so who knows. At least the wealthy Manchesterians must connect somewhere anyway (except for HKG), so EK probably boards whatever high premium traffic is there - rather lay over in an EK lounge than BA. Anyone have stats on EK's flows to/from its spokes?

I think what could happen is Airbus presenting the A380-900 in Dubai, as a "half stretch" to the original planned -900. Then a promise for a 3-5% PIP from Rolls to the current engines, using some Trent XWB technology, and optional XWB-style blended wingtips offering 2-4% decrease in drag. Optional because it would likely add a few meters to the wingspan. I also expect Airbus to develop "Space-Flex" for the A380 and certify the aircraft for 900 seats or so. The result should be a much more competitive aircraft for a fraction of the cost of a NEO.

Although me and many others expect Emirates would buy A380 CEO regardless, I think they'd buy even more A380s if Airbus launched such an aircraft. Tim Clark has been pushing hard for a NEO, but I believe they'd be very happy with a half-NEO as well. Much cheaper for Airbus and Rolls. And I think with the improved CASM and flexibility, they'd potentially sell to other airlines as well.

I'm not dismissing a NEO-launch, but I think this is more likely. And all this is just my humble opinion.

Quoting matt6461 (Reply 48): Think of, e.g., PVG in 2025. The X population willing to bid on, e.g., ORD-PVG will be far greater than current capacity and far greater than the Y population that would bid on typical twin-engine direct flights. We're talking tourists, recent Chinese immigrants to the U.S., and those from literally dozens of secondary/tertiary Chinese cities with over a million people.

It seems to me in 2000 that Airbus felt this largely would have happened by now, and it just hasn't on the scale their 751 frame projection suggests. The broad assumption seemed to be that more economic activity would lead to more people being lifted into a level of wealth that would support purchase of tickets on such routes and we'd need loads of VLAs to move such people. My reading of the evidence is that more economic activity has not lifted such people into a new level of wealth, all it's done is made a much smaller number of people extremely wealthy, so loads of VLAs are not needed. I know this isn't a popular statement amongst aviation enthusiasts, but from where I sit, the wealthy are getting wealthier and not much trickles down. Also from where I sit, lots of people who used to feel OK with spending money on long haul tickets for VFR travel are being squeezed by so many other of life's costs and are not seeing pay raises on the traditional curve (especially in inflation adjusted terms) so the non-emergent market isn't making up the difference.

I also think whatever increase we see in wealth will predominantly result in increased regional flying as opposed to increased long haul flying, and in that case the increased flexibility of the smaller widebodies bodes well for them as compared to VLAs.

Quoting matt6461 (Reply 50): Quoting Revelation (Reply 47): Given its scope of changes, A380X still has exposure to such risks, IMHO. True. But can you grant me that it's a little less risky in addition to being less costly?

Sure.

Quoting matt6461 (Reply 50): I was referring to my reframing of the issue: In a world where the A380 didn't exist, should somebody launch a VLA?

Ok, but we are in a world where the A380 does exist, and each frame built will undermine the case for the A380X to some degree.

Quoting tortugamon (Reply 52): Do you mean LH instead of CX? I think CX has been very cautious in regard to the A380   I think they could have made it work but I do not see an order any time soon.

I meant CX. I think it would be a good match for some of their North America & Europe routes, meeting the criteria I gave earlier of being so long that frequency is not the benefit it is on shorter routes like JFK-LHR.

Quoting Revelation (Reply 56): It seems to me in 2000 that Airbus felt this largely would have happened by now, and it just hasn't on the scale their 751 frame projection suggests.

I suspect the air travel market from 2001 to ~2006 and from 2008-2010 certainly didn't match the market they projected. In a world with two significant economic impacts, SARS etc the growth didn't happen that was expected. On the other hand, an observer who started looking at air travel using 2009 as a baseline probably sees a lot of growth coming up, and may have a more optimistic view.

Quoting JetBuddy (Reply 55): "half stretch" to the original planned -900. Then a promise for a 3-5% PIP from Rolls

This post makes a ton of sense. My little model shows the following results with -3% SFC delta, 15,000lbs OEW delta, and 8% capacity delta, and 7% price delta:

-Fuel/pax delta is -10%
-CASM delta is -7%
-Range about the same, maybe 100nm decrease

I went with -3% SFC delta because GE is also talking about doing this, but ballparks it at 2.5%. http://aviationweek.com/paris-air-sh...-a380neo-gp-upgrade-business-case. Perhaps RR can be more aggressive with a PIP? The only publicly available PIP projection I've seen is GE's at less than 3%, so I'll stick with 3% for now.

This is the way to go IMO, assuming of course a new wing doesn't happen. The Advance NEO gets you only ~3% more CASM delta because it's heavier and would require more investment (thus higher purchase price). This would be a cheaper way to keep the A380's CASM edge over 777 - though not to same extent as now - and see if the market moves towards it at all with traffic growth. Of course I'm not sanguine about that happening, but on Airbus' paradigm this is a good low-cost option to test the theory. I'd bet on your prediction, JetBuddy.

Quoting Revelation (Reply 56): It seems to me in 2000 that Airbus felt this largely would have happened by now, and it just hasn't

...because of the economics. To attract and board transfer pax disproportionately you have to be willing to take a yield hit and the CEO just doesn't give you CASM space to do so with suitable margin for risk.

Quoting Revelation (Reply 56): My reading of the evidence is that more economic activity has not lifted such people into a new level of wealth, all it's done is made a much smaller number of people extremely wealthy

As a flaming liberal I want to agree with you. But I think it's true that, while globalization has exacerbated inequality within Western economies, it has actually reduced it across them. Hundreds of millions have joined the middle class in Asia, a few billion more will come. Airbus is right, imo, that serving these new mostly Y pax will be the biggest business opportunity of next decade.

Quoting Revelation (Reply 56): Ok, but we are in a world where the A380 does exist, and each frame built will undermine the case for the A380X to some degree.

I don't think to a great degree. Only 90 more CEO's will be built at most. An A380X is a little better than even a free CEO, and they won't quite be free. Plus a 12yo frame isn't a long-term solution. Its economics will be attractive those first few years but then maintenance costs start to rise. Used frames will be a good low risk way for airlines to get acquainted with a VLA strategy.




[Edited 2015-07-15 20:11:23]

[Edited 2015-07-15 20:15:47]

Quoting JetBuddy (Reply 55): I also expect Airbus to develop "Space-Flex" for the A380 and certify the aircraft for 900 seats or so.

My one objection to your post. Going to 900 capacity adds zero value imo. I doubt we'll ever see an A380 with 700+ pax, even the "-850." A380 only works for big network carriers and they'll always want/need some premium revenue.

A better approach might be to lower the max pax certification - perhaps you can get ride of some AC packs and ducting and save weight/maintenance/cost as a result. I also wonder whether you could remove the middle upper deck door and reduce pax certification up there to ~150. That could save 1,500lbs because the evacuation equipment up there is unusually heavy to deal with height. You could also then take some weight out of UD floor beams. Those are also disproportionately heavy because their cantilevered span (~20ft) is greater than in any other airliner.

The foregoing changes, however, would need a business case. Probably not gonna pencil out on a NEO/PIP, but presents further opportunities for the A380X/NWO.

Quoting matt6461 (Reply 58): Quoting Revelation (Reply 56): It seems to me in 2000 that Airbus felt this largely would have happened by now, and it just hasn't ...because of the economics.

Airbus's grasp of the economics of the A380 in 2000 has been the cause of many debates here on a.net...

Quoting matt6461 (Reply 58): Quoting Revelation (Reply 56): My reading of the evidence is that more economic activity has not lifted such people into a new level of wealth, all it's done is made a much smaller number of people extremely wealthy As a flaming liberal I want to agree with you. But I think it's true that, while globalization has exacerbated inequality within Western economies, it has actually reduced it across them.

I think you under-estimate the wealth of the upper classes of the East and over-estimate the wealth and priorities of the lower and middle classes of the East, but time will tell. The clear reality is it has yet to transfer into sales of VLA aircraft nor even a trend in such a direction.

Quoting matt6461 (Reply 58): Hundreds of millions have joined the middle class in Asia, a few billion more will come. Airbus is right, imo, that serving these new mostly Y pax will be the biggest business opportunity of next decade.

Still doesn't mean they'll all want to fly routes best serviced by VLAs.

Quoting matt6461 (Reply 58): Only 90 more CEO's will be built at most.

Which means a lot of A380 facilities would have to go into mothballs whilst A380X wings/wing-boxes/tails/landing-gears/engines get designed/implemented/tested/manufactured.

Quoting matt6461 (Reply 58): An A380X is a little better than even a free CEO, and they won't quite be free. Plus a 12yo frame isn't a long-term solution.

The problem is that the A380X decision depends on Airbus deciding it's the best thing for Airbus to do, not that it's the best thing for the airlines.

Quoting Revelation (Reply 60): Airbus's grasp of the economics of the A380 in 2000 has been the cause of many debates here on a.net...

I just mean it's because the A380 isn't as efficient as a VLA should be, especially given its double-deck fuselage. That's an interesting debate, though I'm sure it brought out some of the more toxic/time-wasting/parochial tendencies here. IMO Airbus had the misfortune of defining the plane at the end of the cheap oil era. Their risk and cost versus fuel efficiency tradeoffs would have been different in 2005, one has to believe.

Quoting Revelation (Reply 60): The problem is that the A380X decision depends on Airbus deciding it's the best thing for Airbus to do, not that it's the best thing for the airlines.

These tend to converge... I could actually see many airlines thinking it great for Airbus but bad for them. Those without megahubs would be at a severe disadvantage facing A380X competition.

Quoting Revelation (Reply 60): Still doesn't mean they'll all want to fly routes best serviced by VLAs.

If they can save 10-15% for 2 added hours of travel time, they will. A good VLA has CASM room to offer that deal, the A380 doesn't.

Quoting matt6461 (Reply 25): I took the "news" to be much much smaller: it threw "cold water" on A.net's understanding of RR's NEO attitude - yours and mine. We thought RR was on board, based on Leeham reporting, Ultrafan R&D path etc.

I can go with that  

Quoting speedbored (Reply 26): I'm not sure that Astuteman will be too happy with you claiming to know what he did or did not believe

In this case I'm pretty cool about it - I admitted as much on the previous thread

Quoting Revelation (Reply 34): In any case, human communication is far from perfect, and in the future I will try to be clearer.

I can't argue with that. I'm pretty sure I'll slip up in a post coming soon, and can legitimately expect to be taken to task.

My bottom line is that I thought too much was being made of the "Something has changed" bit.
something clearly did, as RR results were worse than expected.
I could see that delaying a commitment for a year or so, but for me, if the business case makes sense, it would still go forward, given the forecasts for improving financials.
We still don't know for sure that it's ever made sense for RR.
I think Matt's "A-net understanding" phrase is spot on

Quoting Revelation (Reply 34): So why do some people seem to feel RR will "do the heavy lifting" just to complete a road map?

There you go. A good question.
Some of us got hooked into the "I'll selectively believe the 3rd party reports based on my own opinions".
The above has always been your stance, as far as I can see, and reasonably argued too.
Which does make me ask ..
Why did you think something has changed?
I you are right, then RR have never been in for the A380NEO/Advance business case anyway.
And you might be right.

Rgds

People are missing the point. The performance of the A380 is good, it is just very big and fleet planers and route planers see it as a big risk. It is much more conservative to put a 777 on a route. Most airlines are currently doing capacity adjustments with the aim of reducing the number of seats offered to increase the yield from every ticket sold. Very few airlines (ME3 are the obvious exceptions) are aiming to take away traffic from the competition, most are just aiming to make more money with the seats they currently sell. (and for many the load factors are quite okay already)

And as long as this mindset is controlling airplane purchases you can X, NEO or stretch the A380 as much as you want, those airlines simply do not want it.

Quoting seahawk (Reply 63): People are missing the point. The performance of the A380 is good, it is just very big

Rather than repeating my oft-stated arguments about how A380's marginal capacity efficiency isn't great, I'll point everyone to a good discrete analysis of why I think you're missing the point.

Ferpe used to post his wonderful spreadsheets analyzing aerodynamic performance. A particularly good one is here:



Notice that the A380 has lower L/D than any modern widebody. 748 is worse but it's an old design (why did Boeing even bother?).

It should be noted that the spreadsheet contains an error, I believe.
The model's wetted areas are too low. For A380 with 1584m2 fuselage, 710m2 exposed wing, we're already at 3004m2 - Ferpe has the A380 at 2878m2 total. This discrepancy holds for each model.
This discrepancy disappears if you double the wing exposed area, as you should. Ferpe apparently forgot to do this. This is a simple "Forgot to carry the 2," kind of error - Ferpe's still mad smart.

The error, however, is highly favorable to the A380, whose wetted area is disproportionately in the wing. Even though the A380 is inefficient with Ferpe's figures, it becomes even worse for the big bird with true wetted areas.

Now, consider that, against the big twins, the A380 has (1) lower L/D (2) higher SFC (3) higher weight per cabin m2. Given those three factors, we'd expect it to lose significantly on fuel burn. And indeed, Leeham's analysis (also by Ferpe I believe), says A35J and 779 are in a "class of their own." One that excludes A380.

Now, fuel burn isn't everything; it's just the biggest thing. A380 claws back to approximate parity per cabin m2 with 777-9, perhaps, with its other economies of scale. That's basically Amedeo's view - couple grains of salt should go with it. www.amedeo.aero/a380.

You basic error, imo, is to grade the A380's performance in absolute terms. Airliners must be graded according to their efficiency relative to size. Nobody disputes that A35J performs better than 788 on CASM, for example (well maybe Boeing would...). But does that mean A35J is a better plane? No, A35J is bigger so it should be more efficient.

A big double decker should be significantly more fuel-efficient than a single deck for simple aerodynamic and structural reasons. Instead the A380 is worse than single deck competition and it's a crying shame. And it explains much of why it doesn't sell.

Quoting seahawk (Reply 63): Very few airlines (ME3 are the obvious exceptions) are aiming to take away traffic from the competition, most are just aiming to make more money with the seats they currently sell. (and for many the load factors are quite okay already)

Disagree. Many airlines are doing this, they're just using twins to do so.
http://centreforaviation.com/analysi...e-consolidation-ana-and-sia-227224
http://centreforaviation.com/analysi...ch-and-second-schedule-bank-230588
http://centreforaviation.com/analysi...7-300ers-single-class-a330s-229960
http://centreforaviation.com/analysi...ul-planning-european-routes-228607
http://centreforaviation.com/analysi...-up-and-hong-kongmacau-fall-226730

There are more stories about other airlines - China Eastern is making a big 77W-powered push from PVG for instance - but that should prove my point.

[Edited 2015-07-16 00:09:52]

Quoting matt6461 (Reply 58): The Advance NEO gets you only ~3% more CASM delta because it's heavier

Why would it be heavier when the engines are currently projected to be significantly lighter?
http://www.rolls-royce.com/customers...ducts/future-products/advance.aspx

Quoting Revelation (Reply 60): The problem is that the A380X decision depends on Airbus deciding it's the best thing for Airbus to do, not that it's the best thing for the airlines.

True. And I can't see Airbus ever deciding it is even a sensible thing to do, let alone "the best".

When someone with zero industry experience, who has read a few aerodynamics textbooks and collected data from websites like Leehamnews can come up with such a compelling business case for a new version of the A380 in such a short space of time, why do so many people not question why it is that Airbus, with their hundreds of extremely knowledgeable staff, millions of man hours of experience, vast quantities of technical & industry data, and inside access to thousands of airlines and suppliers, has not been able to work it out as well by now?

Surely Airbus can't be that incompetent. Maybe it is because Airbus are working their business cases using real world numbers, not starting their calculations with estimates, guesses and assumptions. I also suspect that, for example, when considering things like a re-wing, Airbus are not simply assuming that they will be able to deliver textbook perfection, and ignoring or dismissing inconvenient real-world factors like manufacturing, parts transportation, damage tolerance, maintainability, certification, airport compatibility, ...

Does anyone seriously believe that an A380X could possibly be 47% more efficient than the current 388? Even all-new aircraft these days are not managing even close to half of that improvement.

Isn't it about time we stopped every A380 thread from turning into yet another off-topic A380X discussion? There are already at least 4 dedicated threads in Tech/Ops about it for anyone who feels it is worth discussing.

All your links show that airlines grow by adding routes and not so much by adding capacity to existing routes, if they do this, they prefer to add frequencies.

And that is a logical reaction to the ME3. The geographic advantage of the ME3 means they cover many city pairs with one stop, so if your hub is less ideal placed your best answer is to offer more direct flights. More direct flights mean serving smaller airports which means smaller aircraft.

A more efficient A380 is only helping the ME3.

Quoting speedbored (Reply 65):

Isn't it about time we stopped every A380 thread from turning into yet another off-topic A380X discussion? There are already at least 4 dedicated threads in Tech/Ops about it for anyone who feels it is worth discussing.

Agreed. This thread sways around like a drunken sailor. If discussion is wanted on each of the issues raised in this thread, why not open a new thread for each item? Then those who are not interested can be relieved of the need to read 80% of this.

Quoting Egerton (Reply 67): Then those who are not interested can be relieved of the need to read 80% of this.

Anybody who doesn't feel like reading a post that mentions the A380X is always free to skip it. I skip certain commenters most of the time... Just roll your eyes and say, "oh this guy again..."

I usually discuss a massively revised A380 as a segue into analyzing the A380CEO and NEO. I then respond to (most) people's questions or objections to the plane.

IMO there's a lack of understanding here about the real issue: A380's efficiency or size-relative lack thereof. That goes entirely to the point of whether a NEO/PIP is a sound investment. If it's not an attractive plane, Airbus shouldn't spend money tweaking it at the margins.

I am simply confounded by the fact that so many people on an aviation enthusiast forum aren't spurred to consider what happens after the CEO's imminent decline, beyond the limited imaginative scope of publicly vetted half-measures. And that they criticize someone who is so spurred and does his - admittedly limited- damnedest to imagine. Some poor souls only find pleasure in trying to tear down others, which is sad (not saying you Egerton - it's fine to be uninterested in a rewing; just skip).

I am sure Airbus is studying a rewing behind the scenes, and I'm sure Airbus' management's stomach turns at the thought of having to do one. Tom Williams designed the A380 wing. He's the EVP of Programs at Airbus. He's unlikely to be pushing management and the board for a redo of his wing now. http://aviationweek.com/singapore-20...330neo-a380-reengining-involvement

Quote: Williams says he does not want to “get sucked into doing a new wing”

So Airbus has ample motive NOT to basically admit past mistakes and launch a huge rewing project. They've been so wrong on the A380 so far, though, that it simply won't do to say, "Airbus knows best."

Criticizing me for imagining a rewinged A380, and for having the gall to post about it, would be like criticizing someone for imagining an A350XWB when the Mark I was launched. I'll keep responding to most posters who ask me about the rewing, and I'll keep pointing out that the A380 is inefficient and could be vastly better.

[Edited 2015-07-16 01:38:13]

Quoting matt6461 (Reply 68): Anybody who doesn't feel like reading a post that mentions the A380X is always free to skip it.

We shouldn't have to. Posts about different topics should be in their own threads.

Just because you don't feel that your pet project is being sufficiently discussed in the many threads you have already started about it does not give you the right to hijack every other A380 thread to get people to discuss it.

Quoting matt6461 (Reply 68): IMO there's a lack of understanding here about the real issue:

So, as well as being the only person who really understands management speak, you are also the only person who knows what the real issue is with the A380, and the only person who knows how to fix it. You should tell Airbus that they need to make you their new CEO asap.

Quoting matt6461 (Reply 68): A380's efficiency or size-relative lack thereof.

What lack of efficiency? It has been the most efficient widebody for many years and can still be pushed further just by increasing seat densities to match those newer widebodies that are now challenging it in the efficiency stakes. Putting on new engines in 5 years time would easily make it beat every other aircraft in the CASM stakes, at similar seating densities.

Quoting matt6461 (Reply 68): beyond the limited imaginative scope of publicly vetted half-measures

So the 737MAX and A320NEO are also "publicly vetted half-measures", are they?

Quoting matt6461 (Reply 68): Some poor souls only find pleasure in trying to tear down others

No, they try to keep discussions on this forum on track and factual. Feel free to indulge your fantasies but do it in your own threads instead of hijacking everyone else's.

Quoting matt6461 (Reply 68): Tom Williams designed the A380 wing. He's the EVP of Programs at Airbus. He's unlikely to be pushing management and the board for a redo of his wing now.

You don't become that senior in an organisation like Airbus by being so precious about decisions you have made in the past. Senior management are, and have always been, more than willing to admit to past mistakes.

The fact that he now does not want to be "sucked into doing a new wing" is because he is sure that it does not make commercial sense for Airbus to do so, not because it is "his baby", or he doesn't want to admit that he got it wrong.

In any case, anyone looking dispassionately at the major design decisions that were made would probably agree that they were the right decisions at the time that they were made. Things have, of course, changed quite a bitt since then.

Quoting matt6461 (Reply 68): So Airbus has ample motive NOT to basically admit past mistakes and launch a huge rewing project.

On the contrary, If a rewing is the right thing to do to maximise shareholder value then they are legally obliged to do it. Airbus management would be committing a serious offence to knowingly make a decision that would not maximise shareholder value, especially if they were doing it in an attempt to avoid admitting to alleged past mistakes.

Quoting JetBuddy (Reply 55):
"half stretch" to the original planned -900. Then a promise for a 3-5% PIP from Rolls
matt6461
This post makes a ton of sense.

I second that.
The 'half stretch' as suggested by Airbus could be a very clever way of optimizing the existing structure.Add the potential of 11 across (18" seats) and galley/loo flex systems and you end up with a ton of extra space that opens up many options. Blended winglets (if applied) would perhaps improve the wing by 4%. And the engine??
It may well be (like the stretch) a 'half advance'.
This is what Rolls is saying for a full advance (not the flexibility the triple spool offers).


Advance
Advance will offer at least 20 per cent better fuel burn and CO2 emissions than the first generation of Trent engine and will be ready for service from the end of this decade.
Advance includes a new core architecture to deliver maximum efficiency and lower emissions. This core takes advantage of the extra degree of freedom in a three-shaft architecture by redistributing the workload between intermediate-pressure (IP) and high-pressure (HP) shafts, resulting in higher efficiency with fewer parts and lower weight. It also benefits from a new lightweight low-pressure (LP) system that, among other system technologies such as advanced lightweight alloys, will feature our new carbon titanium fan system, which comprises the fan blades and the fan casing. While delivering improved propulsive efficiency, the system delivers a weight saving of around 750lb per engine, or, put another way, around seven or eight passengers travelling "free".
Further progressive technologies to be incorporated into the Advance design include: high-efficiency compressors and turbines; smart adaptive and cooling systems; an advanced combustor; superior sealing solutions; and innovative materials.

I look forward to seeing exactly they will do.I feel they should put their carbon titanium fan and casing into production as it surely must represent the future for them (and lower weight).How much of the core gets the advance treatment we will have to see! (It is being tested at the moment in an XWB test core BTW which is interesting I think  

Trent 900 is not a first gen. Trent - so it is 20% to a Trent 700 but probably around 10-12% to a Trent 900 EPII.

Ferpe's modelling of the winglets predicts a 1.7% increase in effective span compared to current wing fences, which would translate into a 2.3% reduction in induced drag. If induced drag is 55% of total A380 drag, that's good for 1.3% L/D delta. A380 already has wing fences so marginal impact will be a little lower. Nonethless 1.3% L/D is great and seems worth doing on a NEO. Split scimitar winglets would make a bigger impact - kind of like the old MD-12 proposal. They might as well max out on effective span as much as possible. Would require bigger mods to the stringers and spars though...

Quoting parapente (Reply 70): Add the potential of 11 across (18" seats)

This has been discussed ad nauseum in other threads but at 11-across the A380 has a little less space/seat than 77W.

Per ACAP seat-level widths:
77W: 231inc @10-abreast=23.1in/seat

A380: [email protected]=22.55in/seat

Ratio changes a bit if you subtract aisles but I'm being lazy. Ordinal versus 77W is my point.

If Airbus raises the floor ~3", that gives another ~3" - assuming the sidewall slope is ~2 in that area.

Now add 3" in floor-raising, subtract 36" from each cabin for aisles:

77W: 195/10=19.5" per seat

A380: 215/11= 19.55" per seat

Airbus needs those extra inches just to equal 77W personal space. And at 11-abreast it's probably a little less attractive than [email protected] Given how many 10-abreast 77W's there are, this might be worth doing as part of the PIP/NEO, but it would require some rework - which is why the recent proposal to just push out an armrest was chosen instead. Not sure if the ROI on that seating density would pencil out... Also the slope might be around 3 at seat level, which would mean a gain of only 2 inches. What's the height of the MD btw? Might raising more than 3" work?

Note that the 18" definition can be played with by moving armrests. Real 18" seats need 20"+ of non-aisle cabin width per seat.

[Edited 2015-07-16 07:15:16]

Quoting astuteman (Reply 62): My bottom line is that I thought too much was being made of the "Something has changed" bit. something clearly did, as RR results were worse than expected. I could see that delaying a commitment for a year or so, but for me, if the business case makes sense, it would still go forward, given the forecasts for improving financials. We still don't know for sure that it's ever made sense for RR.

I think I was very much swayed by AvWeek's article of December saying an accord with RR was imminent and then all the different numbers of frames STC said EK would buy if there was a NEO and his talk of a decision by March. To me it seemed it was a done deal to be announced by this year's Paris airshow. It seems perhaps others were less swayed, and if this is the case, they would not see a lack of progress on a NEO commitment as a change.

Quoting astuteman (Reply 62): There you go. A good question. Some of us got hooked into the "I'll selectively believe the 3rd party reports based on my own opinions". The above has always been your stance, as far as I can see, and reasonably argued too. Which does make me ask .. Why did you think something has changed? I you are right, then RR have never been in for the A380NEO/Advance business case anyway. And you might be right.

My career experience has made me pretty leery of grand road maps. Sure there is quite often a most sensible direction to head in, and communicating that both inside and outside of the company does get people heading in that direction. However what happens more often than not is that supporting and enhancing what has in the field is more significant than the road map planners allow for. What this means is the roll-out of technologies as they reach enough maturity to release rather than a big moon shot that ends up pulling in components of mixed maturity where the weakest link in the chain often lets the side down.

So, in summary, perhaps others put more faith in road maps than I do and so have seen its fulfillment as inevitable, whereas I've not been able to make that leap. Yes, that's the opposite of me buying in to the inevitability of an A380neo in December, but the distinction is that the road map is largely a projection of RR's technical community whereas the December talks seemed to be that of Airbus's and RR's and EK's executive community. In short, I was following the money, not the tech.

Quoting seahawk (Reply 63): The performance of the A380 is good, it is just very big and fleet planers and route planers see it as a big risk.

Yes, I think this point is not appreciated enough. It makes me think that should such aversion to risk be overcome, perhaps A380 will finally start selling on the scale Airbus anticipated.

Quoting matt6461 (Reply 64): Disagree. Many airlines are doing this, they're just using twins to do so. http://centreforaviation.com/analysi...e-consolidation-ana-and-sia-227224 http://centreforaviation.com/analysi...ch-and-second-schedule-bank-230588 http://centreforaviation.com/analysi...7-300ers-single-class-a330s-229960 http://centreforaviation.com/analysi...ul-planning-european-routes-228607 http://centreforaviation.com/analysi...-up-and-hong-kongmacau-fall-226730 There are more stories about other airlines - China Eastern is making a big 77W-powered push from PVG for instance - but that should prove my point.

Which is another way of saying they're not doing it with VLAs, no?

Quoting matt6461 (Reply 68): I am simply confounded by the fact that so many people on an aviation enthusiast forum aren't spurred to consider what happens after the CEO's imminent decline, beyond the limited imaginative scope of publicly vetted half-measures. And that they criticize someone who is so spurred and does his - admittedly limited- damnedest to imagine

I appreciate the attempt to look at things from first principals. It's interesting how others don't challenge them directly, rather they just say Airbus must be smarter and your approach must be wrong. Then, shortly thereafter, they say Airbus just did what they thought was right a long time ago and we have to deal with the consequences.

Quoting speedbored (Reply 69): We shouldn't have to. Posts about different topics should be in their own threads.

If (and I mean IF) you accept the suggestion of the thread starter that cold water is being thrown on the A380neo, it's a pretty natural thing to explore why that might be the case.

[Edited 2015-07-16 09:22:20]

Quoting speedbored (Reply 65): Why would it be heavier when the engines are currently projected to be significantly lighter?

I believe if you re-read the link that you posted you will see that they are referring to the fan system that is lighter, not the engine. Its very uncommon for new engines to be lighter than the ones that they replace and I would expect the Advance will be no different. Though a 750 lb lighter fan is great and its good to see them ditch the titanium blade and 'catch up' to the rest of the market with the CFRP. An exciting engine to be sure.

Quoting matt6461 (Reply 68): Anybody who doesn't feel like reading a post that mentions the A380X is always free to skip it. I skip certain commenters most of the time

I agree. Keep the musings and the calculations coming. Its refreshing to see someone looking at these issues critically instead of emotionally and without any support.

Quoting seahawk (Reply 71): Trent 900 is not a first gen. Trent - so it is 20% to a Trent 700 but probably around 10-12% to a Trent 900 EPII.

If I am not mistaken it would be the Trent 500 that would be the first gen. The A340 came just before the A330 though they are very close. So the Advance will be 20%+ better than 1991 tech. I'd like to know what percentage better the Trent TEN is vs the Trent 500 so we can estimate how much better the Advance will be vs the engine of today (well 2016).

tortugamon

Quoting tortugamon (Reply 75): I believe if you re-read the link that you posted you will see that they are referring to the fan system that is lighter, not the engine.

No, that is not what I will see. What I see is them referring to the engine weight "a weight saving of around 750lb per engine". They then continue to say that this means "7 or 8 passengers travelling free" - how else would they be able to do that if the fan weight saving is cancelled out by weight increases elsewhere?

Quoting tortugamon (Reply 75): Its very uncommon for new engines to be lighter than the ones that they replace

True, but almost always because of increased fan size resulting in heavier fans. That is clearly not the case here.

Quoting Revelation (Reply 74): Quoting seahawk (Reply 63): The performance of the A380 is good, it is just very big and fleet planers and route planers see it as a big risk. Yes, I think this point is not appreciated enough. It makes me think that should such aversion to risk be overcome, perhaps A380 will finally start selling on the scale Airbus anticipated.

I agree that risk is a big part of the A380 story so far, lack of sufficient reward is the other part. Surely there's a risk/reward tradeoff at which the marginal efficiency gained from a bigger plane is worth its risk.

I think the A380 is far from the efficiency point where the risk/reward tradeoff swings non-EK airlines to order A380s. I don't think the NEO/PIP gets us there. Airbus can wait, as you say, for risk aversion to subside but imo it's a rational feature of good airline management - not going anywhere.

Quoting Revelation (Reply 74): Which is another way of saying they're not doing it with VLAs, no?

Right but I was responding to a claim that airlines aren't trying to grab market share. Outside of the U.S., plenty are. I have a different explanation for why they're doing it with twins rather than A380, won't lard it on again...

Quoting Revelation (Reply 74): I appreciate the attempt to look at things from first principals.

Quoting tortugamon (Reply 75): Keep the musings and the calculations coming.

I appreciate your dialogue and thoughts, everything I've learned from folks like you here over the last year or so.

Was it not 15% to the first T700 version?

http://www.rolls-royce.com/sustainab...ies/improving-fuel-efficiency.aspx

Advance is 20%

Ultrafan is 25%

Trent 7000 is said to be 10% to the latest T700, which itself had about 5% PiP, so T7000 ~ Trent Ten

Trent 900 should be at 10% to the original 700, with PiPs. So if they find another 3-4 percent it would be close to the Trent Ten.

Quoting speedbored (Reply 65):

Isn't it about time we stopped every A380 thread from turning into yet another off-topic A380X discussion? There are already at least 4 dedicated threads in Tech/Ops about it for anyone who feels it is worth discussing.

Quoting Egerton (Reply=67)

Agreed. This thread sways around like a drunken sailor. If discussion is wanted on each of the issues raised in this thread, why not open a new thread for each item? Then those who are not interested can be relieved of the need to read 80% of this.

Quoting matt6461 (Reply 68):
Anybody who doesn't feel like reading a post that mentions the A380X is always free to skip it.

Quoting speedbored (Reply 69)
We shouldn't have to. Posts about different topics should be in their own threads.

The Lesson for today is from the Book of Egerton, Chapter 569, starting at paragraph 12.a.iv.

If I buy an ice cream which has a label on it stating 'vanilla', and I open it to find the contents are 'neapolitan' (meaning slices of chocolate, vanilla and strawberry) I tend to be displeased. This ice cream has not conformed to the convention that a product should do what it says on the label. (In the UK it can also be an unlawful deception of the customer, law is stronger than a rule or a mere convention).

If I spend my valuable time (more valuable to me than an ice cream) opening a thread I expect it to be closely aligned to the product description given by the thread starter label. I tend to be displeased if the thread content is in fact mostly irrelevant to its thread starter label.

On A.net we tend to call this tendency 'going off thread' or 'deviating from the thread'.
It is not unlawful, and for small quickly read interventions is can be fun or valuable.

Being a Brit, a convention the like of which I have attempted to describe is an important, accepted part of our language.
It may be that other nations have different conventions - that is fine my me.

But in UK English, the response given in Reply 68 would normally taken as perhaps being rather impolite.
But then our Book of Common Prayer (the basis of our language and in daily use) was written some time ago, in 1662.

As we say in Church, 'Here endeth the lesson'!

[Edited 2015-07-16 09:44:34]

Quoting speedbored (Reply 76): What I see is them referring to the engine weight "a weight saving of around 750lb per engine".

I read:

Quote: It also benefits from a new lightweight low-pressure (LP) system that, among other system technologies such as advanced lightweight alloys, will feature our new carbon titanium fan system, which comprises the fan blades and the fan casing. While delivering improved propulsive efficiency, the system delivers a weight saving of around 750lb per engine, or, put another way, around seven or eight passengers travelling "free".

... as saying the fan system eliminates 750 lbs, and nothing about the overall engine weight.

Quoting speedbored (Reply 76): They then continue to say that this means "7 or 8 passengers travelling free" - how else would they be able to do that if the fan weight saving is cancelled out by weight increases elsewhere?

The new engine with the current fan clearly would be 750 lbs heavier so it still is saving the weight of the 7 or 8 passengers. Presumably other weight gains (due to denser materials or bigger sized components) needed to 'earn their way' onto the engine, by delivering better fuel efficiency, or lower maintenance cost, or less noise, or ...

Quoting matt6461 (Reply 77): I agree that risk is a big part of the A380 story so far, lack of sufficient reward is the other part. Surely there's a risk/reward tradeoff at which the marginal efficiency gained from a bigger plane is worth its risk. I think the A380 is far from the efficiency point where the risk/reward tradeoff swings non-EK airlines to order A380s. I don't think the NEO/PIP gets us there. Airbus can wait, as you say, for risk aversion to subside but imo it's a rational feature of good airline management - not going anywhere.

It is not the plane. The points are yield management and fast connections. If we ignore the ME3 for a moment, every airline only has so many city pairs that can fill a A380 with original demand, one of those cities is typically a hub of the airline.

When the A380 was designed the idea was that people would fly to the hub use the A380 to the next hub and connect from there. The reality is that people do not want more than one stop. (this needs to be remembered for any route between Europe and Aisa / Australia which the ME3 can do with one stop)
On the Asian routes all airlines having hubs not placed as well as the ME3 hubs, are better served with smaller planes, so they can offer one stop connections.
And that is why European airlines open new destinations in America instead of flying A380s to the hubs and why US Airlines do rather fly a 757 over the pond than a A380. One stop wins.


No CASM improvement will change this.

Quoting Revelation (Reply 74): I think I was very much swayed by AvWeek's article of December saying an accord with RR was imminent and then all the different numbers of frames STC said EK would buy if there was a NEO and his talk of a decision by March

Many of us were. Who knows if we were right to be so. Maybe there were never really close to a deal or maybe the deal really did blow up. I am not sure we will find an answer to that.

Quoting speedbored (Reply 76): No, that is not what I will see. What I see is them referring to the engine weight "a weight saving of around 750lb per engine".

From the link, emphasis mine:

Quote: It also benefits from a new lightweight low-pressure (LP) system that, among other system technologies such as advanced lightweight alloys, will feature our new carbon titanium fan system, which comprises the fan blades and the fan casing. While delivering improved propulsive efficiency, the system delivers a weight saving of around 750lb per engine

It seems to reference this system (carbon titanium fan) is what is lighter. Further illustrating the point other sources have indicated this exact amount when discussing how much lighter the fan is and this relates to a completely different engine (its a Trent 1000):

"The CTi fan system includes carbon/titanium fan blades in a fantastic cyan blue color. The system also has a new composite casing that reduces weight by up to 1,500lb per aircraft, the equivalent of carrying seven more passengers at no cost."
http://planelopnik.kinja.com/rolls-r...anium-fan-bl-1646620295/1646636438

Quoting seahawk (Reply 78): Was it not 15% to the first T700 version?

Is this in response to my post? Are you saying the Trent TEN is ~15% better than the Trent 700? I would be surprised if it was that high. Only number I know about the Trent TEN is it is supposed to be 3% better then the current Trent 1000 which is a great achievement in my opinion. Thanks for the clarification.

tortugamon

Quoting Egerton (Reply 79): a product should do what it says on the label.

This one is labeled "Cold Water on the A380NEO." Call me November rain - I'm trying to soak and freeze this thing.

The FG article was meaningless IMO, except as to A.net perceptions of NEO likelihood. Thus we're properly hashing out - should/will this thing launch?

Quoting Egerton (Reply 79): But in UK English, the response given in Reply 68 would normally taken as perhaps being rather impolite.

Being a Chicagoan ("City of Big Shoulders" "Windy City" - for our big mouths) that counts as excessively polite. But when in Rome... I shall have to study deeper in your Book good sir.

Quoting matt6461 (Reply 83):

Being a Chicagoan ("City of Big Shoulders" "Windy City" - for our big mouths) that counts as excessively polite. But when in Rome... I shall have to study deeper in your Book good sir.

I am obliged to you, Good Sir, for your consideration.

Quoting tortugamon (Reply 82): Is this in response to my post? Are you saying the Trent TEN is ~15% better than the Trent 700? I would be surprised if it was that high. Only number I know about the Trent TEN is it is supposed to be 3% better then the current Trent 1000 which is a great achievement in my opinion. Thanks for the clarification. tortugamon

Yes, in the link they say 15% to the first T700 and 12-13% to the first T800.

Quoting tortugamon (Reply 75): If I am not mistaken it would be the Trent 500 that would be the first gen.

I'll have to find the link, but I'm pretty sure the reference point is the Trent 700

Quoting tortugamon (Reply 82): Is this in response to my post? Are you saying the Trent TEN is ~15% better than the Trent 700? I would be surprised if it was that high. Only number I know about the Trent TEN is it is supposed to be 3% better then the current Trent 1000 which is a great achievement in my opinion

Rolls-Royce say the Trent 7000 is 12% more efficient than the Trent 700 at the engine level (-2% extra drag at the aircraft level).

Quoting seahawk (Reply 85): Yes, in the link they say 15% to the first T700 and 12-13% to the first T800

Have a care. The 15% figure relates to the gap between the Trent XWB and the Trent 700, not the Trent 7000 and Trent 700

The "Advance" should be about 5% more efficient than the Trent XWB, some 7%-8% more efficient than the Trent 1000 and some 10% more efficient than the Trent 900 currently on the A380

Rgds

I find it odd that in every A380neo thread including this one it is taken for granted that an Advance engine for the A380neo will add considerable weight to the frame, and thus will "eat up" some (read: most) of the fuel burn improvements. This in spite of that all RR ever communicates about the Advance is how their new lightweight materials will save weight on the engine.

The reasoning behind this foregone conclusion evolves over time:

First:
The Advance will be heavier, because it is only the fan that will be lighter, and the fan is just a small component of the engine, compared to the - no doubt - much heavier core.

Then, when that is debunked:
The Advance will be heavier, even if new lightweight alloys and production techniqes go into the core as well. This is because of the - for sure - added weight of the third compressor stage, or change in Compression Ratio or ...

Latest alteration:

Quoting tortugamon (Reply 75): Its very uncommon for new engines to be lighter than the ones that they replace and I would expect the Advance will be no different.

  

Well, guess what: If RR has their focus on making the Advance lighter, maybe - just maybe - they will accomplish just that!
  

Quoting speedbored (Reply 69): What lack of efficiency? It has been the most efficient widebody for many years and can still be pushed further just by increasing seat densities to match those newer widebodies that are now challenging it in the efficiency stakes. Putting on new engines in 5 years time would easily make it beat every other aircraft in the CASM stakes, at similar seating densities.

What matt says is very very probably right. While the A380 has been the most efficient frame per floor area until very recently it's just not efficient enough for it's size to compensate all the restrictions like ground footprint, restricted cargo and so on. And the main reason by fare is all the design compromises Airbus did with the A380. Anybody with basic understanding of modern Airplane design can see this. Ferpe did an excellent job on this ones.

That's not that I totally by into the A380X concept while I think it's more-or-less a clean sheet.

Quoting dare100em (Reply 88): That's not that I totally by into the A380X concept while I think it's more-or-less a clean sheet.

I'd prefer that we don't associate a new wing with the specific contents of my maximalist A380X design. I admit that I might have got carried away with revisions there. It's fun to tweak, e.g., tailplane weight and then watch the weight/drag implications cascade to engines, wing, landing gear and back to the tailplane. Really fun. Even if I'm off on the precise numbers it's nifty to see the interlocking implications of design on engine/frame maintenance and capital cost when you pull on this or that lever. I've said anybody who wants to play along can have the spreadsheet - [email protected]

I'd prefer everyone discuss rewinging with whichever additional tweaks they'd like. Or none. I think a new wing+engines alone get ~30% trip fuel delta with smaller, cheaper engines. You can then keep the stretch capability for future -900X. TBH it's probably a more prudent approach than my maximalist design. Without a stretch and new empennage it's simpler than the 777X, but yields far greater results than 777X because 77W's wing ain't shabby. Anybody want to champion that route?

I don't claim ownership over the -X or -NWO concept. Anything that at least unbinds A380 from its too metal, too big, too heavy, too short wing will probably do. Just please don't allow Airbus' PR to determine the scope of your imagination or of our discussions. OEM's often try to pitch a low risk solution until the market forces them to invest. Think 767 "Hunchback of Mukilteo"(became 777), A350MkI. They're studying a wing, guaranteed. They won't launch it if they can get away with a NEO. Don't settle (I imagine shouting at TC).

Quoting hilram (Reply 87): I find it odd that in every A380neo thread including this one it is taken for granted that an Advance engine for the A380neo will add considerable weight to the frame, and thus will "eat up" some (read: most) of the fuel burn improvements.

Mark Lapidus doesn't find it so odd and he knows a thing or two about the A380.

Quote: Lapidus is skeptical about the reengining, because he expects fuel cost savings to be eaten up by higher weight and maintenance if currently available engines were taken. He argues that the difference between existing A380 engine technology and what would be available soon is not big enough.

Lest you think "currently available" excludes the Advance, Lapidus specifically targets Ultrafan for NEO, so he knows of the Advance and its availability ~2020.

Quote: Lapidus would like to see Airbus wait for the next generation of engine technology before moving to a new powerplant. He sees that technology nearing with the arrival of Rolls-Royce’s proposed ultrafan project, which includes geared turbofan technology.

http://aviationweek.com/commercial-a...stretch-and-reengining-around-2025

EDIT - Yes, Lapidus has 20 very good reasons to downplay a NEO. But he's not going to say something stupid in public to make his case. He knows that knowledgeable people will know whether it's true that Advance will be heavier and more costly to maintain - and that when he comes knocking with his great idea - buy A380s! - they'll trust him less if he's running around saying stupid things.

[Edited 2015-07-16 12:39:10]

[Edited 2015-07-16 13:07:00]

Quoting tortugamon (Reply 82): It seems to reference this system (carbon titanium fan) is what is lighter. Further illustrating the point other sources have indicated this exact amount when discussing how much lighter the fan is and this relates to a completely different engine (its a Trent 1000):

OK, just for the sake of discussion, let's go with your interpretation.

So we have a saving of 750lbs per engine from the fan and casing. These are the parts that usually add weight with newer engines by virtue of the fact that they have been significantly increasing in size.

At the same time, with each newer generation engine, the manufacturers have been consistently pushing more and more performance out of engine cores by virtue of better aerodynamics, better cooling, higher speeds, better combustors, higher temperatures and pressures, new exotic materials like ceramic composites and other such innovations.

Yes, some of the most recent engines have had to add stages to the engine in order to increase pressure ratios but one of the core innovations for the Advance is to reverse that trend by having more HP stages and fewer IP stages, so an A380 Advance engine will most likely have the same number of stages as the existing engine, but with more of the smaller HP stages and fewer of the larger IP stages.

Given the available information from RR at the moment, I can't really see anywhere in the engine where weight would need to increase significantly, if at all. If anything, it seems to me that core size and weight is more likely to decrease. Perhaps you could explain where in the engine you see a weight increase that would offset the saving from the fan and casing?

Quoting seahawk (Reply 71): Trent 900 is not a first gen. Trent - so it is 20% to a Trent 700 but probably around 10-12% to a Trent 900 EPII.

The 20% are against the first Trent 700. We have the Trent 700EP2 and the

Quoting seahawk (Reply 78): Trent 900 should be at 10% to the original 700

Make that rather 5%difference between T700 and T900. The EP2 brought 2+% for both, including EP1, and now is the talk about a further pip bringing 2 to 3% extra for the T900. That would move the T900 to near 10% difference to the Advanced.
I would expect the TXWB, T1000ten and the T7000 to come out 4 to 5% better than the expected new version of the T900EP3, 5 to 6% below the advanced.

Quoting matt6461 (Reply 89): Yes, Lapidus has 20 very good reasons to downplay a NEO

You said it!

Quoting matt6461 (Reply 89): Lest you think "currently available" excludes the Advance

I do. You can not buy one for any airliner, can you? It's still in testing stage.

Quoting hilram (Reply 92): Quoting matt6461 (Reply 89): Yes, Lapidus has 20 very good reasons to downplay a NEO You said it!

Wow can't believe you caught that. Well done.

...the larger engine´s fan does not necessarily mean its higher mass: fan´s mass depends on the material used in the blade´s construction, the blade´s thickness, their aerodynamic profile, the construction of the blade´s root as and the creation of the central load-bearing part of the structure of the fan.

The lighter fan could imply the need for a smaller dimension of those sections of the engine´s core which are directly connected to the fan. This means that the reducing of the fan´s weight could also affect the reduction of the certain part(s) of the engine´s core (scaling-down or reducing the number of the stages), but, on the other side, the using of the lighter materials in the fan´s construction opens up the possibility that fan can rotate on the higher speed...

Rolls - Royce, working on each subsequent construction of the engine, and which are rather comparable by their thrust, starting with the Trent 900 (116˝ fan), through the Trent 1000 (112˝ fan) and, finally, the Trent XWB (118˝ fan), has been changing the architecture of the engine´s core, so Trent XWB has one stage more on the IPT section (2 stages) than Trent 900 and Trent 1000 and one stage more on the LPT section (6 stages) than the Trent 900, and the same number as Trent 1000.
Trent 800, f.e., although with the significantly higher thrust and smaller fan (110˝) has the same core´s architecture as the Trent 900 (1-8-6-1-1-5) and the dry mass of the Trent 800 is very comparable and very approximate to those masses of Trent 900 and Trent 1000, but significantly lower than the Trent XWB´s.

Since the fans of the mentioned engines are constructed of the very similar materials, and despite of the unquestionable differences in their masses due to the differences in their diameters and their constructions, I believe that the architecture and the construction of the engine´s core keep the biggest secret about engine´s weight (on this occasion I will not talk about the engine´s auxiliaries)...

Undoubtedly, the difference in the choice of the material of which the fan is constructed can significantly influence the reduction of its weight, but that does not mean that the engine itself, will be lighter.
How different are nowadays trends in the construction of the turbofan engines, nicely describes the fact that Rolls - Royce consciously increased the mass of the engine structure, by changing the architecture of its core, but the end result of that compromise was the most fuel efficient and the most advanced turbofan engine in the world, in this moment -Trent XWB. It will be very interesting to see how much added weight will Trent XWB-97 get in the comparison to the Trent XWB-84, with the same diameter of the fan (I expect the very similar fan construction), but scaled-up core. Also, the future version of the XWB engine, aimed for the possible A350-1100 will probably have the larger fan, but will be made of the very different material...

Nice regards

Mario

P.S. Some other time, we could compare the constructions of the Boeing 787´s engines (GEnx-1B and Trent 1000) as well as the future Trent 1000-TEN.

Quoting matt6461 (Reply 89): Quote: Lapidus would like to see Airbus wait for the next generation of engine technology before moving to a new powerplant. He sees that technology nearing with the arrival of Rolls-Royce’s proposed ultrafan project, which includes geared turbofan technology. http://aviationweek.com/commercial-a...stretch-and-reengining-around-2025

I don't see how they could wait to 2025 for a new engine. There are 113 months till 1/1/2025 rolls around and only 151 left to deliver (that includes the 52 iffy orders as mentioned up threat). They will need a bunch of new orders to get there...

Quoting matt6461 (Reply 93): Wow can't believe you caught that. Well done.

Quoting hilram (Reply 92): I do. You can not buy one for any airliner, can you? It's still in testing stage.

Can't believe you've missed this. Impressive.

Quoting tortugamon (Reply 15): Quoting matt6461 (Reply 11): 640t is for -900 right? Airbus included space for a fifth rolling truck in the -800 design, meant for the -900 and, I believe, the freighter. That is the way I understand it. I think there were some posts on here about a year ago that led us to believe that the MLG was fine as is. I am not sure if there was a formal source on it. With the way they designed everything else to work for the A389 its not really much of a surprise really.

The 5th truck would be for a weight increase at the very high end. The intermediate proposal calls for adding brakes back to all wheels. At present, only 16 of 20 have brakes to save weight.

Quoting tortugamon (Reply 75): If I am not mistaken it would be the Trent 500 that would be the first gen. The A340 came just before the A330 though they are very close. So the Advance will be 20%+ better than 1991 tech. I'd like to know what percentage better the Trent TEN is vs the Trent 500 so we can estimate how much better the Advance will be vs the engine of today (well 2016).

You're confusing the 340-200/300 with the 500/600. The 200/300 came out with the CFM56-5C, which even then wasn't cutting edge (it was an "oh shit" replacement for the canceled Superfan and necessitated wingspan increases and winglets), while the 500/600 came out with the T500 in the late 1990s. The T500 has the same fan diameter as the T700 and a scaled core from the T800, so at minimum it has better FPR efficiency versus a T700.

Quoting LH707330 (Reply 97): The 5th truck would be for a weight increase at the very high end. The intermediate proposal calls for adding brakes back to all wheels. At present, only 16 of 20 have brakes to save weight.

Do you mean the "-850NEO?" Have design details leaked that I missed?

BTW - random A380 question. Does anyone know what A380's cargo load factors are for, e.g., EK and SQ? I was thinking that perhaps the A380's preponderance of pax capacity, and the attendant crowding out of other widebodies when successfully deployed, would lead to excess demand for belly cargo and a higher load factor for A380 underfloor. But I remember someone mentioning EK as saying 77W carries 23t cargo on average, A380 8t. Googled to no avail. Even though the A380 is bad on cargo, those numbers are a little worse than expected given EK's 77W pax density.

Quoting matt6461 (Reply 98): BTW - random A380 question. Does anyone know what A380's cargo load factors are for, e.g., EK and SQ?

It has to be very high since EK immediately told Airbus to pound sand when 11Y was floated as the way to reduce casm going forward. I think EK will only accept a stretch for capacity increase due to cargo loads.