Quoting zeke (Reply 96): I think history has shown the SA2 (A320), YA9 (A330) and TA11 (A340) identified passenger demands well in advance and produced popular aircraft still used in the market almost 25 years later, the forecasts are normally 20 year projections to match the life span of a major investment like a new airframe.

I agree those are all popular and successful, but we were talking about forecast *accuracy*. At launch, Airbus grossly underestimated A320 and A330 demand, and overestimated A340 (although their estimate assumed the SuperFan was available). Boeing did the same thing for the 737 and 747. Boeing hasn't (yet) grossly overestimated a new type but they totally shanked it on derivatives (767-400ER, 747-8i, etc.).

My point was that the OEM's really suck at actually getting the correct demand estimate...typically, they either go way low or way high from reality.

Tom.

Quoting ferpe (Reply 86): If B has gone to a 6 wheel boogie for the 787-10 I think it is a clever move, it gives the 787-10 a long life with several MTOW hikes going forward (and we know how successful that is as mid-life kickers )

I gather we are to assume that there will be no 787-10 at ~251t MTOW ... or do we? The 6750nm range at max passenger load does not need more than the 251t. So is that behind us and is SU-H's ideal of 7000nm plus now more likely?
Have you given thought to where the first MTOW might be with the new MLG?

Quoting sunrisevalley (Reply 101): I gather we are to assume that there will be no 787-10 at ~251t MTOW ... or do we?

I guess it depends on how accurate Aviation Week's reporting is, as they are the ones reporting Boeing is at least considering a 6-wheel bogie and a revised SOB join to support higher wing loadings.

Quoting sunrisevalley (Reply 101): Have you given thought to where the first MTOW might be with the new MLG?

I would imagine Boeing would want an MTOW similar to the A350-900 to allow a similar fuel load to be carried to provide similar range (the 787-10 will be able to carry around 18-27 more people). So between 270-275 tons.

Quoting Stitch (Reply 102): I would imagine Boeing would want an MTOW similar to the A350-900 to allow a similar fuel load to be carried to provide similar ra

What options do Boeing have to increase the fuel capacity from the present ~101t ?

Quoting sunrisevalley (Reply 103): What options do Boeing have to increase the fuel capacity from the present ~101t ?

The issue with the 787-10 is not fuel volume at MTOW, but fuel weight at MTOW.

If we take Aspire Aviation's numbers, a 787-10 with a 251t MTOW and 191t MZFW can tank 58 tons - 57% full tanks.

The A350-900 at 268t MTOW and 192t MZFW can tank 76 tons - 70% full tanks (Airbus shows the fuel capacity at 108t).

So increasing MTOW would allow more fuel to be tanked.

Quoting CXB77L (Reply 88): Quoting rheinwaldner (Reply 76): In my theory Boeing wanted the 787 to stay away from the 777, which would be an mistake from product strategy perspective. No, not a mistake. They designed the 787 to be primarily a 767/A330 replacement.

There is a difference between a shortsighted 767/A330 replacement and a clever design that is fully capable to replace 767's at one hand and does not pose restrictions regarding later upgrades on the other hand.

There are a lot of things you can do enable later upgrades in a more easy way that don't impair the first versions notably.

Just look at the 787 cross section. For a pure 767 replacement 8.6 abreast is a terrible cross section to choose. But it is a great example how assets have been injected into a design, that would not have been needed for the initial versions. That design decision alone (which was very wise and exceptionally far-sighted) has put the 787 firmly into the neck of the 777. Even the smallest 788 does increase the 767's payload/range/size-capability to an extent, that putting the two in the same league is insulting the 787.

If you draw little dots on a floorspace/range diagram for the 763ER, the 788 and the 772ER you will see that the 788 sits a lot closer to the 772ER than the 763ER. And still the 788 is the primary 767 replacement. Already the 789 would match the 772ER's position and the 781X will leave behind both A359 and 772ER.

Nobody should be suprised if the 787 continues creeping into 777 territory and eventually cover any spot that has been held by 9-abreast 777's. Its just a matter of time.

Quoting astuteman (Reply 91): Quoting rheinwaldner (Reply 85): A 787-based A359 competitor should really not require any more MTOW to achieve A359 capabilities. And hence also not more wheels. Except, as Ferpe has pointed out the wheels on the A359, are much bigger, have a higher pressure, and are further apart, than the wheels on the 787-9.

On the other hand the 789 has a more narrow fuselage, has lighter wings and engines. I really can't imagine that the 787 would need 6-wheels to compete with the A359 if stretched to the same length. Too similar are all these parameters. And b.t.w. the lower tire pressure of the 787 does not increase surface loading but reduce it....

Quoting sweair (Reply 98): What range would a ER version have to have to replace the 772ER?

The 789 has already the cabin-length of the 772ER. And as the 772ER's are almost all 9 abreast this means that the 789 is already there. Having a lot more range than the 772ER.

So the 6-wheel 781X is not about the 772ER.

It is strange to see how people almost stubbornly "invent" aircraft against which this 781X should compete. First the A359, now the 772ER. But nobody seems to recognize that this flavour of a 787 will run against the A351 (IMO). At 340 seats nominal the A351 will face tough competition from such a 781X. Doing the 748i trick Boeing could sell it as-350 seater...

Quoting rheinwaldner (Reply 105):

Your problem is that you keep thinking the 787 is the A350. It is not! The 787 was never designed to replace the 777, Y2 is 787 Y3 is the 777 replacement, get it?

Airbus will try to cover the 220-350 seat market with one family, Boeing thinks they can do this with 2 different families. If you stop being so stubborn things will get clearer.

Quoting rheinwaldner (Reply 105): On the other hand the 789 has a more narrow fuselage, has lighter wings and engines. I really can't imagine that the 787 would need 6-wheels to compete with the A359 if stretched to the same length.

Well if the goal is to only match (or exceed) the A350-900's capacity, then yes, the 787-10 does not need any additional MTOW. However, such a 787-10 would not match the capability of the A350-900 in terms of payload/range at the outer ends of the spectrum.

So if you want to match an A350-900 out to around 5000nm, no worries.

If you want to match an A350-900 out to around 8000nm...   

Quoting astuteman (Reply 91): Where've you been, my friend? Both CX and now QR have ordered 43 between them since July

Asleep. I was not aware of these orders; my life has been quite complicated in the last six months-you may have noticed that I have not been posting very often lately.

Quoting sweair (Reply 106): Your problem is that you keep thinking the 787 is the A350. It is not! The 787 was never designed to replace the 777, Y2 is 787 Y3 is the 777 replacement, get it?

That was once the idea, but since then a lot has happened. And the weight and size increases of the B787-versions -9 and -10X (proposed) put a heavy strain on that claim which you make. Not to mention the B777-X proposals instead of an all new successor to the B777. Also that is by far not so black and white anymore as it was maybe 5-6 years ago. The world has changed. Get it?      .

Quoting xxxx (Reply 100): My point was that the OEM's really suck at actually getting the correct demand estimate...typically, they either go way low or way high from reality.

I fail to see how they could actually be all that accurate anyhow? The world changes and unless they have a crystal ball, how can they know all possible ramifications of what's to come? Certainly there are many parameters that they can model, but then there's the surprises...

Quoting Stitch (Reply 102): I guess it depends on how accurate Aviation Week's reporting is, as they are the ones reporting Boeing is at least considering a 6-wheel bogie and a revised SOB join to support higher wing loadings.

These "leaks" always seem to be put back on the OEM's as if they were press releases. Then the thrashing and bashing begins...

Quoting rheinwaldner (Reply 105): If you draw little dots on a floorspace/range diagram for the 763ER, the 788 and the 772ER you will see that the 788 sits a lot closer to the 772ER than the 763ER. And still the 788 is the primary 767 replacement.

Were there an A330NEO or an A322NEO, I think it would be less of a 767 replacement than it is right now. If/when Airbus (followed by Boeing) announce a new narrowbody lineup that is in the 175/200/225-ish range with transatlantic range, sales of the 787-8 will likely be the next 767-200ER (past) or 777-200ER (current) as aircraft that are seldom ordered.

Quoting sweair (Reply 106): Your problem is that you keep thinking the 787 is the A350. It is not! The 787 was never designed to replace the 777, Y2 is 787 Y3 is the 777 replacement, get it?

It is what it becomes. Until the Y3 becomes more than an internal concept, the 787 gets to become whatever Boeing and the airlines decide it can be. Back when the 7E7 was formulated, we had the 7E7 (Y2) coming out in 2008, the 797 (Y1) coming out in 2012, and then Y3 (whatever it was to be) coming out mid-2010's. Oh, and Airbus was going to be relegated to a distant 2nd. Flash ahead 8 years and you'll see that things have not gone as planned. There is no money to do all of that, no need - yet - to do the Y1, and no clear path forward - yet - to do the Y3.

I have absolutely zero clue what Boeing is going to (or should) do, but it would make sense to me to do the 787-10 as a more capable platform such as described in this thread, tweak the 777 to get a few more years of decent sales out of it, but put all their cards into the true 773/748/388 replacement aircraft mid 20's, with a new Y1 coming late 20's. Were that to be the case, the 787 would be "promoted" to low-end 777 replacement, even though it initially wasn't supposed to go that way.

Quoting sweair (Reply 106): Airbus will try to cover the 220-350 seat market with one family, Boeing thinks they can do this with 2 different families. If you stop being so stubborn things will get clearer.

I think it remains to be seen what Airbus does in that market segment. Today is one thing - five years from now is another. Just as Boeing ponders different options, so does Airbus. An A330NEO/Lite could conveivably become the new 250 seat, mid-range people mover that replaces much of the 767 capacity in a more effective and perhaps less expensive manner than the 787. And they could probably have it on the market for delivery while there are 787 customers waiting for their planes.

Hey, it probably won't happen, but it could. And if it does, Boeing needs to get as much out of the 787 as possible. Might as well take it up-market rather than cannibalize it from both ends with the A330NEO and the 777X.  

-Dave

I ran the different variants to do a PR chart to help the discussion.

The -10ER is 270t with an OEW of 135t ie showroom spec, the -10 is 251t with 132t OEW, -9 251 with 125 and 359 268 with 136. The engines on the -10ER has to be 80klbf to get acceptable start performance and a top of climb of 300ft/min at FL310. As can be see the -10ER is just fuel limited at the design range of 8000nm, maybe a bit tight (as always click on the chart to see better):




I have made no changes to the -10ER wing, the -9 proposed extended wingtips might do it good, haven't check what it does however. Engines are TWXB and T1000TEN, the latter being 1% of from the TXWB TSFC.

Put a graph of the 787-10ER+A3510 and the 77W/9X, that would probably explain why the 787 will never replace the 777 for some. Payload range is payload range..

Quoting sweair (Reply 112): Put a graph of the 787-10ER+A3510 and the 77W/9X, that would probably explain why the 787 will never replace the 777 for some. Payload range is payload range..

Of course it will never replace the 777 for some. That doesn't mean it can't replace the 777 for many. For the ones whom it doesn't, is there enough of them to warrant investing billions into a 777X - following billions invested in a 748 - only to once again replace if prematurely with a clean-sheet design? I doubt very much that Airbus will stand still during all of this.

-Dave

The 787-9 should pretty much handle the same missions as the 777-200ER (at 6-abreast Business / 9-abreast Economy) with better efficiency.

So Boeing really need only worry about the 777-300ER at the moment.

As to protecting that plane, I still believe a "777-300ERX" with 115,000lb GE-9X engines makes more sense than the 777-8X / 777-9X.

Quoting sweair (Reply 112): Put a graph of the 787-10ER+A3510 and the 77W/9X

Added (and busy  ) , it shall be noted the -8X and -9X have engines that are 4% better then TXWB, this means end of the decade and some development risk IMO:



-8X MTOW 315t with 158t OEW, -9X with 344 and 172, both with 71m wings.

Quoting ferpe (Reply 115): Added (and busy  )

Thanks for your hard work and quick reactions to posts here.   Your graph is very enlightening.

Quoting ferpe (Reply 115):

Thanks, that is making our debate so much better, great graphs!

@ ferpe

The 777-9 cabin m2 seems off... Is it?

Quoting mffoda (Reply 118): The 777-9 cabin m2 seems off... Is it?

The cabin areas per m2 are as follows: 789 266, 7810 -10ER 296, 359 291, 351 330, -8X 322, -9X 370

What you see concatenated after the frame name is the average fuel consumed in kg over 1000nm and then divided by cabin m2 to normalize it between the frames. I use m2 cabin to avoid the whole seating discussion with things like class distribution and 8 vs 9 vs 10 abrest comfort levels etc. Wingedmigrator proposed it in a Tech/Ops thread and it makes sense for first order normalization purposes avoiding the whole complexity of seating. One can also see that for a certain cabin comfort level there goes roughly 1 pax per m2, if you take my m2 figures as pax above the positioning of the frames in capacity fits our discussions somehow over the different threads.

Now if one want to go to a more exact comparison one would have to do a cabin for all frames with the same principles for comfort, galley sizing etc and then divide by seats to get kg per seat-mile but that is for the airlines to do  .

Re normalized fuel consumption, suffice to say that all these frames are in the 39 to 40 kg range with only the -9X dipping below at 38.4 kg/nm/m2. It is also average fuel consumption when flying their spec mission, it cost fuel to carry fuel for those last miles so one can only really compare frames with the same spec range. The -10 only have a 6900nm nominal range and therefore has a lower average fuel consumption, should not be directly compared with the 8000nm frames.

To really compare things like fuel consumption one shall fly all frames over the same distance, say 3000 and 6000nm. Then the result is more representative. Further such results shall be taken as an indication, the model is not that exact and I also do the cabin m2 by cabin length * cabin width ignoring front and back cabin taper etc. Therefore I normally don't show any fraction for the fuel but did it this time as they are all so close. To use with caution   .

[Edited 2012-12-05 22:02:46]

Quoting astuteman (Reply 91): Quoting frigatebird (Reply 63):I guess increasing the length by adding 2 wheels is a less complicated solution for the 787-10X. It may be quite the opposite. The aircraft was designed to accommodate a twin bogie. It's brave to assume that the wheel well has room for a triple bogie.

No, that is not what I said. I said it was a less complicated solution - less complicated than further increasing the size of a 4 wheel bogie, especially in width. Pretty sure a 4 wheel bogie as wide as the A359's will never fit on a 787. Ferpe once posted 2 pics comparing the thickness of the wing roots of both 787 and A350, the latter one looks about 50% thicker.

Quoting Stitch (Reply 107): So if you want to match an A350-900 out to around 5000nm, no worries. If you want to match an A350-900 out to around 8000nm...

The 789 is a great 772ER competitor as well as the A359. So do you think that the 787 would lose 3000nm range, just by stretching it 2-3 meters to come close to the A359?

Quoting sweair (Reply 106): The 787 was never designed to replace the 777, Y2 is 787 Y3 is the 777 replacement, get it?

So it was aimed at the 767 replacement market only?

That's rubish because the 787 is far too much 777-like for that. The first 787-versions have longer ranges than any other new design before (that means it is a high performance twin aisles aircraft from the outset) and it has a cross section which would be pure waste if the 767 and the A330-market would have been the sole purpose.

Quoting ferpe (Reply 115): Added (and busy ) , it shall be noted the -8X and -9X have engines that are 4% better then TXWB, this means end of the decade and some development risk IMO:

Thanks for the charts. I have some observations:

- It is not plausible why the 779X would have significantly more range and payload while it will have roughly engines with the same power as the A351. Something does not add up. I could imagine that Boeing makes a 400-seater from the 77W with less thrust by giving up some range and probably payload. But extending range, payload and size while reducing thrust and weight is simply not credible.

- It does not make sense to spend 6-wheels MLG to the 781 if the gained payload increment would turn out so small. Your MTOW-assumption for the 781ER is biased to make the difference look small. If you would recalculate using an MTOW that would match the potential of the 6-wheel MLG and assume other changes (that would still cause comportably less effort than planned for the 77X), you will see that the 787 could be brought very closely to the A351.

- Looking at payload alone does hide a lot of relevant parameter because it tells nothing about the pax/freight split. As a full A380 has almost no reserves to carry cargo, a 781ER could have virtually the seating capacity of a A351 while the payload would be consumed by a higher percentage for pax instead for cargo. A characteristic which could suit a lot of customers at least as well as the other way round.

Quoting frigatebird (Reply 120): No, that is not what I said. I said it was a less complicated solution - less complicated than further increasing the size of a 4 wheel bogie, especially in width. Pretty sure a 4 wheel bogie as wide as the A359's will never fit on a 787

Ah. Apologies. My Bad.
Yep. I get that.  

Rgds

Quoting CXB77L (Reply 88): The 77W may lack outright passenger capacity against the 744, but beats it in just about every other way, including payload and range. I disagree with the notion that airlines are trading 744s for 77Ws due to a want of smaller aircraft, but rather they are doing so because the 77W is a more capable aircraft.

Agreed - that also means that airlines are not clamouring for the 405 seats of the 777-9X and would be happy with less if they could get the required capability.

Quoting CXB77L (Reply 88): In terms of gross costs, I disagree that the 777X program "far exceeds" what is required to develop larger and higher MTOW 787s.

I disagree, a heavier 787 will likely use an extended wing of around 65m which would be based on the existing 787 wing - Boeing originally proposed a larger wing for the 9 and 10. The costs involved would be far less than the full cost of developing a completely new wing for the 777X.

The 777X represents the most ambitious derivative program in terms of scope and cost ever proposed by Boeing. Previous major late life upgrades included the 737NG, 744 and 748 - none of these programs involved significant changes in materials, assembly techniques or the supply chain as will occur with the 777X.

Airbus had almost exactly the same concept for the 350 Mk1 which was costed at around $5.5 billion in 2004 dollars, throw in inflation, scope creep, schedule slippage and all the other unkown unknown's and the 777x is likely to exceed $10 billion in cost. It has much of the capital cost and risk associated with a new platform but doesn't have the advantages of long life and further derivatives - Y3 will be the next cab off the rank.
Its not a case of whether Boeing can do it but rather a case of is the 777X the right thing to do with $10 billion or more - you come up against the law of diminishing returns when investing huge amounts of capital late in the life cycle.
The 748 is a good exampe of over investing in a derivative - while the market did not materialise, Boeing could still have gernerated a ROI if the development costs had been much lower.

Quoting CXB77L (Reply 88): Quoting StickShaker (Reply 59):the 777X program represents a massive investment in a mature platform, far exceeding that required to develop a 787-10/11 with similar capabilities and also with much greater risk. Any 787-10/11 would have a life span of at least 30 years - far more than could ever be possible with the 777X which I suspect could struggle to sell sufficient frames to generate an acceptable ROI. ...... .......I also disagree that it would struggle to sell.

Yes it will sell but the qualifier is "to sell sufficient frames to generate an acceptable ROI".
With such a massive upfront capital investment the 777X will need to sell a huge number of frames to recoup that investment and then earn some income. With that size of capital investment the 777X will need to either sell like hot cakes or have a very long life cycle for a derivative. The more that is invested in the 777X then the further out to the right the launch of Y3 will need to be pushed. The 777X will never have the market to itself as occurred with the 77W - it will be competing in a very diferent world against much newer and very capable competitors.

Quoting CXB77L (Reply 88): I think the 777-9X has a reasonably bright future. Any airline that's currently operating the 777-300ER at 10-across in economy would find the 777's extra width attractive in order to maintain on board product commonality.

Your right, it will probably sell in reasonable numbers - but would the present value of the 777X exceed that of a 777+ (5% improvement) launched much earlier and costing far less to develop. The 777X also does not satisfactorily address the 300-350 seat market where a heavier 787 derivative would be such a formidable competitor.

The concept might not necesarily be one of a heavier 787 replacing the 77W but rather supplimenting it by by exploiting as yet untapped potential of the 787 platform. There will likely still be the need for a heavier and larger platform but I'm not sure that the 777X is the best way to fill that need - the 777+ may be a better way to go.

Quoting PlanesNTrains (Reply 113): Quoting sweair (Reply 112):Put a graph of the 787-10ER+A3510 and the 77W/9X, that would probably explain why the 787 will never replace the 777 for some. Payload range is payload range.. Of course it will never replace the 777 for some. That doesn't mean it can't replace the 777 for many. For the ones whom it doesn't, is there enough of them to warrant investing billions into a 777X - following billions invested in a 748 - only to once again replace if prematurely with a clean-sheet design? I doubt very much that Airbus will stand still during all of this.

Good summary.


Regards,
StickShaker

Quoting rheinwaldner (Reply 121): The 789 is a great 772ER competitor as well as the A359. So do you think that the 787 would lose 3000nm range, just by stretching it 2-3 meters to come close to the A359?

It is not the loss of range, but the loss of payload to meet that range.

At their respective Maximum Zero Fuel Weights, the higher MTOW of the A350-900 allows it to tank an additional 18 tons of fuel which translates to some three hours of additional cruising time using Airbus' estimates.

Quoting rheinwaldner (Reply 121): As a full A380 has almost no reserves to carry cargo, a 781ER could have virtually the seating capacity of a A351 while the payload would be consumed by a higher percentage for pax instead for cargo.

A 75m 787-11 would offer some 52 LD3 positions - 8 more than the A350-1000 and 777-300ER - so cargo volume won't be an issue for her.  

Quoting rheinwaldner (Reply 121): - It is not plausible why the 779X would have significantly more range and payload while it will have roughly engines with the same power as the A351. Something does not add up.

Why not, the engines are 4% more efficient, that is a lot (half of the efficiency improvement of a A333neo).

Quoting rheinwaldner (Reply 121): But extending range, payload and size while reducing thrust and weight is simply not credible.

Weight is frame+ fuel and fuel burn goes down 10%, ie trip fuel no longer weighs 140 but 120t, there you have 20t. Thrust is set by start and top of climb, start is to 80% induced drag, there your 71m helps (look in past threads how much, has been discussed several times). Top of climb suffers a bit but is over strong on twins anyway so it is OK for a -9X.

Quoting rheinwaldner (Reply 121): - It does not make sense to spend 6-wheels MLG to the 781 if the gained payload increment would turn out so small. Your MTOW-assumption for the 781ER is biased to make the difference look small. If you would recalculate using an MTOW that would match the potential of the 6-wheel MLG and assume other changes (that would still cause comportably less effort than planned for the 77X), you will see that the 787 could be brought very closely to the A351.

If you read what I write I say the MTOW is engine limited for a 787 stretch, the 6 wheel gear is there because you're past the limit for a 4 gear design that fits the 787 belly (if AW has the right info). This does not mean you can suddenly make the frame a 300 tonner, other things needs major changes then.

Quoting ferpe (Reply 125): This does not mean you can suddenly make the frame a 300 tonner, other things needs major changes then.

And one would reasonably expect those other things to change as well (greater span/larger wing area, higher thrust engines, etc.) in order to both support those higher MTOWs and to maximize their benefit.

And we're unlikely to see a direct jump from 250t to 300t - I could see the first jump being to, say, 270t to equalize the "TOW Gap" to the A350-900.

Quoting Stitch (Reply 126): And we're unlikely to see a direct jump from 250t to 300t - I could see the first jump being to, say, 270t to equalize the "TOW Gap" to the A350-900

Probably not by coincidence, at 270t MTOW the required fuel load including reserves for max passenger load at max range of about 7800nm is right on the tank capacity of just over 101t.

Quoting ferpe (Reply 125): other things needs major changes then.

Sure, but isn't it reasonable to assume that other major change would come with the 6-wheel MLG?

How weird would it be, to have only that one specific major change (6-wheel MLG) if the increment would be so small as shown in your chart?

No, it is safe to assume that Boeing does analyse a package of several major changes and the 6-wheel-MLG are just that part which became evident. Otherwise it makes no sense. This can clearly be seen in your chart....

Could someone please post the link to the article? I have been looking but unable to find it.

This would be big news. Last I've heard is that the 787-10 MTOW would be the same as the 787-9

Quoting ZOTAN (Reply 129): Could someone please post the link to the article? I have been looking but unable to find it.

I'm guessing it is in the print edition.

Quoting Stitch (Reply 130): I'm guessing it is in the print edition.

Nope, the the headline is funny: http://www.aviationweek.com/Article....e-xml/AW_12_03_2012_p40-522315.xml

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

So stronger SOB. Updated wing. Updated undercarriage. Upgraded ECS.

All would support higher TOWs and additional stretches.

Quoting Stitch (Reply 132): So stronger SOB. Updated wing. Updated undercarriage. Upgraded ECS.

Thanks.

One line that explains a lot.

It took me countless posts in many threads to explain the rationale behind such an upgrade. And faced strong opposition by many. It does not fit into a world view where the 777 should keep its current relevance for a long time despite being sandwiched by three new clean sheet designs (two of them of a revolutionary new kind).

How often I got kindly reminded (garnished with verbose explanations) that the 781 would "only" be planned as simple stretch? And boom, that plan seems to become invalid (as it happens now and then with plans)....

And still almost nobody seems to believe, that this will be Boeings primary answer to the A351. But I still do.

This means also that this will be their primary effort to stay present in the 350 seat market. Because it is better to compete there with a 340-seater, than with a 400-seater, you know. Range&payload will be fine and sufficient for the bulk of all airlines as well.

Quoting rheinwaldner (Reply 133):

You really think the 777 has no future? And that it is optimal to have one family to cover 230-400 seats? The span is too great to cover with one frame, hence you see how the A358 falters in the lower range, it is just too much airframe! The 748i is not a top seller, so no 400 seat option there, end the 777 and the top model would have 320 seats. To go beyond the 787-10 length will be a major pain for Boeing, it would become the new A340-600. The frame is not designed to go to the 77W size.

To EOL the 777 and not do a Y3 would be the most stupid mistake B ever could do.

One thing about Boeing that I like is how they move slowly and carefully.This is how they have achieved such a fantasic record of success with their models over they years.

The only recent mistake (if one can call it that) is the 748. But even here, even though it is locked into losses at present, is doing an interesting job. It removed Airbus from the heavy freight market,kept it 'honest' on every 380 they have sold, and racked up a few 'i' orders.But they, by now, have presented and re presented the aircraft to all and sundry. The picture is not rosy.

So they are feeling airlines out. An improved 300 then a a smaller 8X a larger 9X both with a new wing attached.And that is what we have ben hearing about for the last year or two.Over the same period Airbus has made a big change to their 1000.Clearly this is what their customers were demanding. Indeed it looks like it is now taking precident over the -8 model.

None of which will have been lost on Boeing. It appears they have now swiveled their 'guns' and have pushed the 777 offerings into the background (poor responses?) and offering to plug the gaps (A333 and A359) with 2 potental stretched versions (heavy and light) of their brand new platform (787).

This IMHO is exactly what they will do now.

As for the large aircraft segment - who knows. As others have said, It begins to look more and more like they will wait and (after the 10X) developments produce a totally new aircraft to replace the 773 and 748 . In the mean time the 773er continues to do very nicely thank you.

Quoting astuteman (Reply 91): But I can't see any reason why the 787 can't be stretched to at least the same length (and hence same capacity) as the A350-1000

I didn't mean that it would be physically impossible to do so, but rather that it'd be impractical and entail many structural changes to the current 787 to "beef up" the fuselage and increase its strength.

Quoting rheinwaldner (Reply 105): Already the 789 would match the 772ER's position and the 781X will leave behind both A359 and 772ER.

The 787-9 is pretty much a replacement for the 777-200ER. As is the A350-900.

However, the A350-900 is the better, more capable 777-200ER replacement for airlines that want to use their aircraft on longer haul missions. The 787-9 falls short of the A350-900's payload beyond 5000nm, as Ferpe's chart shows. The 787-10, without the upgrade, would've been even worse in that regard, as a simple stretch with the same MTOW as a 787-9. What the inclusion of six wheel main gears does for the 787-10 is increase its MTOW so that it can match the A350-900's payload range figures - and even beat it. But it still falls a long way short of the A350-1000.

Quoting rheinwaldner (Reply 105): Nobody should be suprised if the 787 continues creeping into 777 territory and eventually cover any spot that has been held by 9-abreast 777's. Its just a matter of time.

I doubt that the 787 would be stretched any further than the -10. So there is still a gap at the top end of the 777 family that can only be replaced either by the A350-1000 or by the 777X.

Quoting rheinwaldner (Reply 105): It is strange to see how people almost stubbornly "invent" aircraft against which this 781X should compete. First the A359, now the 772ER.

The 787-10 doesn't compete against the 777-200ER. It replaces it.

Quoting PlanesNTrains (Reply 113): Of course it will never replace the 777 for some. That doesn't mean it can't replace the 777 for many. For the ones whom it doesn't, is there enough of them to warrant investing billions into a 777X

I think there is, particularly if the 777X turns out as good as it has been reported could be. The 777-9X and the A350-1000 sales battle isn't a "one or the other" proposition. I think it is quite likely that airlines would order both to operate alongside each other, as the 777-9X is the larger and more capable aircraft. If the airlines can make more money from the 777-9X's added payload range capabilities than they lose from the fuel burn deficit, then I fail to see why the 777-9X wouldn't be on their shopping list.

Quoting ferpe (Reply 115):

Thank you for your hard work in putting that graph together, Ferpe. It just goes to prove my point that the 787-10 isn't really a match for the A350-1000 even with the upgraded main gear, and that is quite evident from looking at your payload range chart. At 6000nm the A350-1000 would carry about 7t more than the upgraded 787-10. The 787-10"ER" is much closer, payload range wise, to the A350-900 than the A350-1000.

Quoting ferpe (Reply 119): The cabin areas per m2 are as follows: 789 266, 7810 -10ER 296, 359 291, 351 330, -8X 322, -9X 370

Thank you for that. There's been too much emphasis placed on seat count. I think the cabin area figures show clearly where the 787-10 is at in terms of size.

Quoting rheinwaldner (Reply 121): The 789 is a great 772ER competitor as well as the A359. So do you think that the 787 would lose 3000nm range, just by stretching it 2-3 meters to come close to the A359?

That wasn't Stitch's point. According to Ferpe's chart, the original 787-10 could match, or even beat the A350-900 in terms of payload until around 4250nm. Beyond that, the A350-900 builds up a sizeable advantage in payload-range. The 787-10"ER" fixes that, and its payload range figures now pretty much match the A350-900 until about 8000nm. It is therefore a much better A350-900 competitor than the previous version.

Quoting rheinwaldner (Reply 121): it has a cross section which would be pure waste if the 767 and the A330-market would have been the sole purpose.

It was designed originally to be a comfortable 8 abreast layout but with the option of going to a higher density 9 abreast layout for carriers that want to have that option. Boeing's early cabin mockups show the seats arranged in a 3-2-3 configuration. That puts it smack bang in the A330/A340 territory. As more and more carriers went for the 9 abreast layout - possibly due to ever spiralling fuel prices, its demonstrator aircraft were fitted with a 3-3-3 configured economy. But that doesn't change the fact that the cabin cross section is narrower than it would be had it been designed as a 777 replacement in the first place.

Quoting rheinwaldner (Reply 121): But extending range, payload and size while reducing thrust and weight is simply not credible.

Yes, it is.

Lower trip fuel burn = less fuel required to be carried for the same mission = lower MTOW without affecting payload. It also increases range.
Larger wings provide greater lift, therefore less thrust is required.

Quoting rheinwaldner (Reply 121): It does not make sense to spend 6-wheels MLG to the 781 if the gained payload increment would turn out so small.

It does, because without the 6 wheel landing gear, the 787-10 wouldn't be able to compete with the A350-900, although it would still be a very good A330-300 replacement. Clearly, Boeing doesn't think that's enough.

Quoting rheinwaldner (Reply 121): Looking at payload alone does hide a lot of relevant parameter because it tells nothing about the pax/freight split. As a full A380 has almost no reserves to carry cargo, a 781ER could have virtually the seating capacity of a A351 while the payload would be consumed by a higher percentage for pax instead for cargo. A characteristic which could suit a lot of customers at least as well as the other way round.

Payload isn't just about cargo, it's also about range. If an aircraft has an excellent payload range performance, then it can theoretically fly a long way - such as westbound on a transpacific route against a stiff headwind - without (or with less) weight penalties, so it doesn't have to leave pax, bags or cargo behind. The more it carries, the more money it makes.

Rather than focusing on seat count, CASM or trip fuel burn, I think that payload-range is one of the most, if not the most important factor when deciding on aircraft purchases, because that affects how much money an airline is able to make from the aircraft. Based on payload range, the 787-10 without a 6 wheel landing gear would have been a fantastic A330-300 replacement, but it would struggle against the A350-900. This upgrade brings it more in line with the A350-900 but it is still somewhat short of what the A350-1000 can do. That's why the 777X, particularly the 777-9X, is still required. Irrespective of what Boeing chooses to do with the 787-10, it will never be able to supplant the 777-9X.

Quoting StickShaker (Reply 123): I disagree, a heavier 787 will likely use an extended wing of around 65m which would be based on the existing 787 wing - Boeing originally proposed a larger wing for the 9 and 10. The costs involved would be far less than the full cost of developing a completely new wing for the 777X.

Then I guess we'll have to agree to disagree here. If Boeing are to use a heavier 787-10 as the basis for its long haul twin from here on in, and replace the 777-300ER and 777X programs with it, it'll need more than just a new wing. It'll also need a new landing gear, new engines, new wing to body join, and various structural "beefing up" to handle the increase in MTOW. It is not an insignificant task. Neither is the 777X an insignificant task, granted, but if it has one advantage at all, then it's the fact that they aren't increasing the MTOW for the 777-9X but rather reducing it, and as such, Boeing do not need to engineer a new main landing gear for the 777X.

Even if I were to concede this point, would a heavier 787 result in a more competitive - and by implication, more capable in terms of payload-range - airframe than the 777X program could achieve? I'll call on Ferpe's talents and expertise here - if he reads this - to see if he can create a payload-range comparison for a hypothetical higher MTOW 787-10 (pick a number, whatever you think might be possible - never mind the fact that there's a lot more work that needs to go into it to make it possible) against the 777-8X/777-9X and A350-1000?

Quoting StickShaker (Reply 123): The 777X represents the most ambitious derivative program in terms of scope and cost ever proposed by Boeing.

I don't think anyone would suggest that the 777X is anything but a significant update of the 777 family.

Quoting StickShaker (Reply 123): The 777X will never have the market to itself as occurred with the 77W - it will be competing in a very diferent world against much newer and very capable competitors.

Neither will the 'Y3' or a heavier 787 have the market to itself. So as far as that point is concerned, there is no difference. I don't dispute that it will need significant sales in order to turn an acceptable RoI for Boeing, but I disagree that the 777X would struggle to reach that magical number, whatever it happens to be. As expensive as the 777X is, I doubt it will be more expensive than the 'Y3' or, indeed, doing a heavier 787. And the 777-9X's size and payload range advantage over the A350-1000 could mean that airlines will operate both aircraft side by side rather than one or the other.

As long as the 777X remains competitive - and I have no reason to believe why it wouldn't be - then having the Y3 being pushed further and further to the right isn't a problem. Ideally, from my point of view, the 777X will hold the fort against the A350-1000 with both having more or less an equal share of the market, while the Y1 comes in the mid to late 2020s and the Y3 comes in the mid 2030s. As someone who is partial to the 777 family of aircraft, I concede that I might be viewing this with rose coloured spectacles clouding my objectivity, but I fail to see why the 777X, with a significant enough update - can't take the 777 a further 20 years into the future before bringing its all new replacement to the market. The 737 and 747 families have both been around significantly longer than the 777, yet they're both still being sold, albeit with varying degrees of success.

Quoting StickShaker (Reply 123): The 777X also does not satisfactorily address the 300-350 seat market where a heavier 787 derivative would be such a formidable competitor.

On this point, I don't disagree.

Quoting StickShaker (Reply 123): The concept might not necesarily be one of a heavier 787 replacing the 77W but rather supplimenting it by by exploiting as yet untapped potential of the 787 platform.

Then I think we might have been talking at cross purposes here. I agree that a heavier 787 is beneficial to the 787 program as there is, as you say, untapped potential, and that it would supplement the 777. However, I also believe that the 777, and the 777X, will continue to exist irrespective of what Boeing chooses to do with the 787. Their futures are not interdependent.

Quoting rheinwaldner (Reply 133): And still almost nobody seems to believe, that this will be Boeings primary answer to the A351. But I still do. This means also that this will be their primary effort to stay present in the 350 seat market. Because it is better to compete there with a 340-seater, than with a 400-seater, you know. Range&payload will be fine and sufficient for the bulk of all airlines as well.

You can believe what you want. I remain unconvinced. You're placing too much emphasis on seat count and not enough on payload range and completely ignored Ferpe's cabin area figures which shows that the 787-10 is indeed closer to the A350-900 than the A350-1000. I also don't know where you got 340 seats from as the "typical" seat count for the 787-10 is 323 seats.

The 787-10, even with the 6 wheel landing gear, still falls short of the A350-1000's payload range and seat count.

Quoting EPA001 (Reply 18): Maybe, maybe not. But these changes to the B787-10X are influencing the business case for the B777-X-program. For sure the B778-X is now an even more highly doubtful proposal imho.

Quoting rheinwaldner (Reply 133): It took me countless posts in many threads to explain the rationale behind such an upgrade.

The 787 started out as a upsized version / replacement of the 767, it is not the league of the 777W in terms of range and capacity at longer ranges, it can certainely be more efficient than the 777W on the lower ranges.

The question is does the world need a 777W replacment, an a/c which can travel its current max range with it max cargo to suit that range, if the answer is no, then the A350-900 and 787-9 and 748i are all fine, but Airbus seems to think that they need to get closer to the max performance figures of the 777W so they are working on the A350-1000.
Boeing has to decide if they are going to leave the market segment where the 777W max performance number reside, efficiency is only one metric, wanting to carry 350+ pax 7,000nm is one issue which cannot always be replaced by taking 300+ pax 6,000nm more efficiently.

Unless Boeing designs a new version of the 787 which is wider than the existing a/c negating the need to make a long thin looking a/c to accomodate 777W loads and range, I do not see any version of the 787 replacing the 777W at its maximum ranges, which is where the a/c presently excels and has no competitor.

Quoting sweair (Reply 134): You really think the 777 has no future?

Not at all.

777's will be built easily for another 10 years even if doing only some minimalistic improvements. Which would mean that there are a lot of $$$'s to earn for Boeing without noteable effort. Which means that earning back the collosal investment for the 77X proposal would require the 777-franchise to sell another thousand copies until 2030 or so. Which is questionable to ever happen...

The correct discussion is about the right balance between investment and return. The 77X is an extreme proposal in that regard. A huge investment and huge risks whether it will stay competitive for that long period until the investment is payed back.

Quoting sweair (Reply 134): And that it is optimal to have one family to cover 230-400 seats?

Not at all.

Nobody needs a A351 competitor with 400 seats. If no 400 seater does exist airlines will do what they do today if they want a 230-seater: order something else that is as similar as possible in size.

400-seaters are currently such a hot market, that you can be happy if you don't participate.

Quoting rheinwaldner (Reply 138):

Emirates liked the idea of putting up to 380 seats and have a notch more range than the current 360 seat 77W. Its a big step between the A350-1000 and the A380, depending on where the line is for profit in a A380, might be well above 400 seats. The market wants less option in your opinion? I think its the other way, they want something between the mega 380 and the 350 seat twins. Just because the 748 is not popular doesn't say that there is no market above 350 seats and below 460 seats.

Quoting CXB77L (Reply 136): Rather than focusing on seat count, CASM or trip fuel burn, I think that payload-range is one of the most, if not the most important factor when deciding on aircraft purchases, because that affects how much money an airline is able to make from the aircraft.

The two most important strategic decisions for any type are fuselage cross section and payload/range curve. Those, much more than anything else, determine whether the airlines want it or not.

Quoting par13del (Reply 137): The 787 started out as a upsized version / replacement of the 767, it is not the league of the 777W in terms of range and capacity at longer ranges, it can certainely be more efficient than the 777W on the lower ranges.

This is a bit inverted...the 787 is a range/payload/speed/crew equivalent *downsized 777*. The demand the 787 i's filling was caused by the aging out of the 767's but if you look at all the characteristics of the aircraft it's absolutely clear that it was intended to be a "777 for routes without enough demand for a 777." This also makes it capable of filling all the 767 roles. Note that this line of argument doesn't apply to the 787-3, which I'd argue is why the -3 went away.

Tom.

Quoting rheinwaldner (Reply 138): Which means that earning back the collosal investment for the 77X proposal would require the 777-franchise to sell another thousand copies until 2030 or so. Which is questionable to ever happen...

I can't see any reason why the 777, with substantial upgrades in the form of the 777X, can't keep selling from now until the mid 2030s, when I expect its all new replacement to then take over. The 777 is still a relatively young and advanced airframe with huge potential for further development.

Quoting rheinwaldner (Reply 138): Nobody needs a A351 competitor with 400 seats.

Tell that to EK. Tell that to AF. Tell that to every airline that puts a high density 10-across seating configuration in a current 777-300ER. I think the evidence is quite clear: as there are more and more airlines adopting a tighter 10-across economy on their 777s, there is a greater demand for a larger 777-300ER. That's where the 777-9X slots in.

Quoting sweair (Reply 139): The market wants less option in your opinion? I think its the other way, they want something between the mega 380 and the 350 seat twins. Just because the 748 is not popular doesn't say that there is no market above 350 seats and below 460 seats.

  

Quoting tdscanuck (Reply 140): The two most important strategic decisions for any type are fuselage cross section and payload/range curve. Those, much more than anything else, determine whether the airlines want it or not. ...the 787 is a range/payload/speed/crew equivalent *downsized 777*. The demand the 787 i's filling was caused by the aging out of the 767's but if you look at all the characteristics of the aircraft it's absolutely clear that it was intended to be a "777 for routes without enough demand for a 777."

Thank you for your input, Tom. That makes a lot of sense.

[Edited 2012-12-07 05:59:59]

Quoting rheinwaldner (Reply 133): How often I got kindly reminded (garnished with verbose explanations) that the 781 would "only" be planned as simple stretch? And boom, that plan seems to become invalid (as it happens now and then with plans)....

To be fair, until the Aviation Week article that started this thread, all of the talk from Boeing and analysts was that the 787-10 would indeed just be a "simple" stretch of the 787-9, leveraging all the systems and components of that model.

The only folks talking about a "787-11" or "787-12" were a.net members.

Quoting CXB77L (Reply 136): If Boeing are to use a heavier 787-10 as the basis for its long haul twin from here on in, and replace the 777-300ER and 777X programs with it, it'll need more than just a new wing. It'll also need a new landing gear, new engines, new wing to body join, and various structural "beefing up" to handle the increase in MTOW.

And all of this is what Aviation Week says Boeing is at least looking at.

Quoting sweair (Reply 134): You really think the 777 has no future?

You should read better. Nowhere in his post is he suggesting this.

Quoting parapente (Reply 135): An improved 300 then a a smaller 8X a larger 9X both with a new wing attached.And that is what we have ben hearing about for the last year or two.Over the same period Airbus has made a big change to their 1000

All changes Airbus made between the A350-900 and the A350-1000 are at best at the size of 5% of what Boeing is proposing for the B777-X Program. It is the other way around, Airbus makes small changes to the A350-1000 to get a very competitive airframe. Boeing needs to do an awful lot of changes to the "good old B77W" to keep her competitive only because she is bigger (as the B777-9X). The B777-8X will still lose out easily against the all new A350-1000.  .

Quoting CXB77L (Reply 136): I doubt that the 787 would be stretched any further than the -10.

But now for sure the opportunities are there.

Quoting CXB77L (Reply 136): As long as the 777X remains competitive - and I have no reason to believe why it wouldn't be - then having the Y3 being pushed further and further to the right isn't a problem

Only if she remains competitive. Then I agree with you. If not, Y3 is the next move to make by Boeing.

Quoting sweair (Reply 139): The market wants less option in your opinion?

Again you should read better, nowhere in his post is he suggesting this.

Quoting Stitch (Reply 142): The only folks talking about a "787-11" or "787-12" were a.net members.

Seems they were quite visionary A-net members. I recall that I have also talked a couple of times about a possible B787-11 or -12.  ,

Quoting EPA001 (Reply 143):

He dismissed the 400 seat market, but as I see it a realistic 400 seater has max 380 seats in airline layout. Why settle for 50% of the 350 seat market when you have a product that can go above and create its own niche? Want up to 340-350 seats go Airbus, want more go Boeing.

In EKs cabin the A350-100 would have below 340 seats anyway.

Quoting sweair (Reply 144): nd create its own niche?

And that is where the risks are. The niche might easily be too small to make a decent ROI for such an extensive redoing of the B77W. Then Y3 would be the better choice imho.

Quoting rheinwaldner (Reply 105): There is a difference between a shortsighted 767/A330 replacement and a clever design that is fully capable to replace 767's at one hand and does not pose restrictions regarding later upgrades on the other hand. There are a lot of things you can do enable later upgrades in a more easy way that don't impair the first versions notably.

I admire your persistence, but efficiency is a spectrum not a case of shortsightedness. If they design extra capability in the 787 to allow for additional stretches and increases in MTOW without significant redesign, then they have overdesigned the 787-8, put too much weight in the design, and hurt its efficiency. Airbus is running into this problem with the A350. While trying to offer the -800/900/1000 they are facing problems with efficiency on the -800. The airplane is overweight for its intended capacity and payload and many suspect that it will suffer the same fate as the 777-200 A market. Airbus also is facing problems pushing the A350-1000 high enough without requiring significant redesign and similarly is receiving negative comments from customers.

It isn't a case of shortsighted design. It is optimized design. A single airplane cannot efficiently cover a spectrum of 150,000 - 200,000MTOW without significant design changes.

Conventional design practices usually result in an airplane being overdesigned by about 10% to allow stretches and MTOW increases. That was the logic used during the design of airplanes prior to the 777. The 787 had extra pressure on efficiency with skyrocketing fuel prices, and they reduced the 10% overdesign gap to make the 787-8 and 787-9 even more efficient, but the consequences are a complicated 787-10 design.

The 77W exceeded the intended MTOW increases for landing gear. The result was significant redesign including semi-levered gear and a dual chamber shock strut.

Quoting tdscanuck (Reply 140): This is a bit inverted...the 787 is a range/payload/speed/crew equivalent *downsized 777*.

Yes, which I take to be the 777-200, 200ER and maybe even the 300, but is it really a downsized version of the 777-300ER, that is what I meant by the 777W, trust I was not wrong in my a/c nomenclature.

Quoting CXB77L (Reply 136): But it still falls a long way short of the A350-1000.

Depends on the MTOW they choose.

Quoting CXB77L (Reply 136): I doubt that the 787 would be stretched any further than the -10.

Maybe you doubt wrongly. Which -10 anyway? Has it been settled?

Quoting CXB77L (Reply 136): If Boeing are to use a heavier 787-10 as the basis for its long haul twin from here on in, and replace the 777-300ER and 777X programs with it, it'll need more than just a new wing. It'll also need a new landing gear, new engines, new wing to body join

Sure. And where is the difference to the 77X?

Quoting CXB77L (Reply 136): You're placing too much emphasis on seat count and not enough on payload range and completely ignored Ferpe's cabin area figures which shows that the 787-10 is indeed closer to the A350-900 than the A350-1000.

Ferpe did pick an unnormally low MTOW for the 781X on that chart. This was an assumption on his part and not a fact. An assumption that is not credible because Boeing would be nuts to spend the enourmous effort for a 6-wheel MLG if the gained payload and range would be so negligible.

Quoting Stitch (Reply 142): To be fair, until the Aviation Week article that started this thread, all of the talk from Boeing and analysts was that the 787-10 would indeed just be a "simple" stretch of the 787-9, leveraging all the systems and components of that model.

It was absolutely. But to me it was always clear that a 9-abreast aircraft, that has the 8000nm range from the outset will eventually become what the 777 today is. This is really not hard to see.

To challenge some of the doubters I specifically call out Tdscanuck, Roseflyer and CXB77L to tell me what size&range they think the largest and most potent 787 version will have in 2025? Please just post two numbers. One for seats, another for range with spec load. If you are not sure how to accomplish the prediction, just apply the average increases in size and range of similar aircraft. Anyway just dare that prediction.

Quoting rheinwaldner (Reply 148):

You keep thinking of the 777 as a 9 across cabin, its going more towards being a 10-across cabin and the 777-X even more so.