enzo011 wrote:

Stitch wrote:

It is unfortunate that PDX Lite is no longer updating the A320no and 737MAX sales charts as I would not be surprised if the MAX's sales surge since the launch of the 737-10 (beyond just the model conversions from existing orders) has probably significantly shrunk the respective "sales per day" metric between the two. And considering the MAX has been on offer for less time, I don't think Boeing is at risk of having anything less than a serious NB presence.

Well the current orders per day for the MAX is 1.84 per day (as per Boeing orders up to 19 December and launch from 29 July 2011). From the PDX numbers when it stopped the number of orders per day has stayed roughly the same (1.86 - 1.84). For the NEO the current orders per day is 2.05 (Orders up to 30 November and launch 1 December 2010). The average order per day has gone down (2.54 to 2.05).

The OEMs can only sell what they have to deliver from this point on, if the delivery slots are all taken as we think they are for the next few years. So delivery slots will be as important to sales in the next decade as that will dictate what sales can be made for either model. Airbus and Boeing is currently selling almost exactly their proposed 2019 delivery rate. So we are where we are I suppose with the amount of sales per day and unless one or both increases the production rate again it seems that the major sales campaigns will take a back seat for now and both will sell around 600-700 of either model per year on average.

Nice summary IMO.

Taking your points in reverse order:

1) Production:
Muilenberg was very bullish at the Boeing 3Q results & speculated that 737 production may exceed 60/month. Boeing, at least, appear to be more focused on a sustainable build-up in the delivery rate than obsessing about a putative "Market Share" - which is a moving target anyway. I see no sign of Boeing worrying that it might need to "go early" on the NSA; and from my much less-informed viewpoint, I can't see it either.

2) Market Share:
Unsurprisingly, the NEO daily-rate has reduced a lot and is now 10% or so above the MAX (your figures). It might stay there, producing something like 52.5/47.5 in favour
of the NEO; or possibly reduce further towards equality. Quite unimportant IMO, as both OEMs will be producing like crazy and banking buckets of money for a decade or more.

I would guess that Boeing will in fact move first on it's narrowbody replacement; but that day is still far far away.
(my two cents )

cheers

enzo011 wrote:

Just as a quirk of statistics, if the Airbus December orders are added (Delta, Pegasus and Viva Air) and the Indigo Partners MOU is firmed before 31 December, then the average sale per day for Airbus shoots up to 2.23 per day. Not as high as the peak, but still enough to add to the backlog in terms of time, which should in theory assist Boeing in countering with sales based on availability. Again, statistics and lies.

Not to mention, those statistics do not show if any vendor is able to command a premium over the other . . .

Just looking at that 'all powerful' source of information -wiki!
But I could not help noticing (deliveries) that it was only 6 short years ago when the A321 became a more important derivative than the A319 for the first time.Clearly orders would have shown an even steeper decline as the A319 is effectively now gone with a few CEO's to be completed.
But then I saw the 2017 deliveries and noted that this is the first year that now the parent aircraft the A320 has also been overtaken by the A321!
Working off similar logic perhaps the forward orders story will also show a more dramatic move to the A321.
Now I'm not saying th A320 is doomed like the A319 (andA318) but the picture is clear.if there is the most demand for the biggest single aisle ac they have then it's likely there is demand above that- where right now there is nothing at all.

It would seem that Boeing think so.Hence the 797.But Airbus must realise it too.After all its their aircraft and their customers!A322 here we come!

It's

However one must not forget, that the A319s often replaced 733s or DC-9/MD-8Xs in the fleets and are not up for replacement yet. While many A310/A300/757/767 are coming up for replacement now.

As we are heading into 2018, let's recap why the MOM business case is so difficult:

“If you bring out an an-new, clean-sheet airplane, you’re taking a market there that is probably 2,000 airplanes. It’s not 4,000, and you’re spending $15bn to develop the airplane. You’ve got to amortize that and every airline is telling you $55m to $75m is all we’re going to pay for this light twin. You’ve got the engine guys telling you the engines are going to be very expensive. The numbers just don’t work.”

Bernstein Research opinion added to the mix:

Bernstein Research thinks Boeing will abandon the NMA, keeping the basic twin-aisle, ovoid concept but down-sizing the range from 4,500nm-5,000nm to no more than 4,000nm to become the 737 replacement.

And once again, it all boils down to engine technologies:

“It’s really the engine technology,” he said. “You’ve got a neo and MAX that are 15%-20% better than the 321ceo. You’re going to have to be 15% to 20% better than [the neo]. That requires real breakthroughs of engine technology. That may be unducted fans, etc. You can’t spend $15bn for an all-new, single-aisle airplane and take today’s technology engines and hang it underneath it. You’ll be 5% better than you are today.”

Leahy said that’s what Airbus looked at with the neo. A clean sheet of paper and an unlimited budget only gave Airbus 5% better on the airframe; the rest came from the engine.

Interview
https://leehamnews.com/2018/01/03/nma-m ... eahy-says/

If Bernstein is right, Boeing goes for a leaner, lighter, cheaper NMA 200-280 seat max 4000NM, it outsources production to Embraer / Mexico and/or joins with the AVIC to set up an Asian FAL, that might kick Airbus out of their comfort zone. But are they capable to do so?

keesje wrote:

If Bernstein is right, Boeing goes for a leaner, lighter, cheaper NMA 200-280 seat max 4000NM, it outsources production to Embraer / Mexico and/or joins with the AVIC to set up an Asian FAL, that might kick Airbus out of their comfort zone. But are they capable to do so?

I do not expect the 737 family of a/c to be replaced by one single frame, regardless of its original intent, the 737 is now a family and most clients in the market will not be looking at just one frame. We also know that Boeing NEEDS to move on its 737 replacement before Airbus, the NSA studies and NEO gave good insight on this theory.
So what that says to me is that the NMA will cover multiple segments with multiple frames, at least more than one, and if that is the case, this will also be the 737 replacement, so how much of the 737 production do you think Boeing will want to and be allowed to move to Mexico and Brazil? A number of states in the USA along with companies have major investments in production facilities geared towards Boeing products, do we expect them to just give up?
Additional thought, on the production question they could also be looking at how to design the facilities where they can be used to make both the larger and smaller frames with
very little disruption, whether that is possible I do not know, but I do expect the larger frame to be first to market followed by the 737 replacement which will be based on the same
core technology.

KarelXWB wrote:

As we are heading into 2018, let's recap why the MOM business case is so difficult:

“If you bring out an an-new, clean-sheet airplane, you’re taking a market there that is probably 2,000 airplanes. It’s not 4,000, and you’re spending $15bn to develop the airplane. You’ve got to amortize that and every airline is telling you $55m to $75m is all we’re going to pay for this light twin. You’ve got the engine guys telling you the engines are going to be very expensive. The numbers just don’t work.”

Bernstein Research opinion added to the mix:

Bernstein Research thinks Boeing will abandon the NMA, keeping the basic twin-aisle, ovoid concept but down-sizing the range from 4,500nm-5,000nm to no more than 4,000nm to become the 737 replacement.

And once again, it all boils down to engine technologies:

“It’s really the engine technology,” he said. “You’ve got a neo and MAX that are 15%-20% better than the 321ceo. You’re going to have to be 15% to 20% better than [the neo]. That requires real breakthroughs of engine technology. That may be unducted fans, etc. You can’t spend $15bn for an all-new, single-aisle airplane and take today’s technology engines and hang it underneath it. You’ll be 5% better than you are today.”

Leahy said that’s what Airbus looked at with the neo. A clean sheet of paper and an unlimited budget only gave Airbus 5% better on the airframe; the rest came from the engine.

Interview
https://leehamnews.com/2018/01/03/nma-m ... eahy-says/

The Bernstein rumor is interesting and is what I would do. Bigger sales segment and more sales opportunities.

Bernstein Research thinks Boeing will abandon the NMA, keeping the basic twin-aisle, ovoid concept but down-sizing the range from 4,500nm-5,000nm to no more than 4,000nm to become the 737 replacement.

There have been debates ad nauseum about whether the MoM should be a narrowbody or a widebody, and now Boeing would supposedly be able to make their widebody design deliver significantly better economics than the A320neo/738Max/CSeries? I find that hard to believe. Downsizing the range + size of the NMA puts it in the firing line of a A32x stretch/re-wing, which is what Boeing would want to avoid for their clean sheet...

Newbiepilot wrote:

keesje wrote:

The 767-200 had higher seatcounts single class & this has nothing to do with Boeing ACAPS or marketing numbers. It's airline numbers.

When Boeing provides seat counts, it is for their standard two class or three class configuration in the standard marketing counts. 220-270 seats are almost identical to the 767-200 and 767-300 seat counts that Boeing publishes of 216 and 261 ( you can find these in the ACAP). You can’t compare these two class seat counts to high density single class max exit limit configurations on the A320 or A321 to support your lie that the article you cited supports your statement:

keesje wrote:

It seems I'm not the only one thinking the NMA will shrink from ~767 size to slightly larger than A320 family

The 767 seating numbers are still "oldstyle", aren't they?
couple of years ago Boeing adjusted their layout numbers to better reflect reality.
How does this fit together. ( modern layout trended towards less seats for the same craft.
that would boost relative size.)

JustSomeDood wrote:

Bernstein Research thinks Boeing will abandon the NMA, keeping the basic twin-aisle, ovoid concept but down-sizing the range from 4,500nm-5,000nm to no more than 4,000nm to become the 737 replacement.

There have been debates ad nauseum about whether the MoM should be a narrowbody or a widebody, and now Boeing would supposedly be able to make their widebody design deliver significantly better economics than the A320neo/738Max/CSeries? I find that hard to believe. Downsizing the range + size of the NMA puts it in the firing line of a A32x stretch/re-wing, which is what Boeing would want to avoid for their clean sheet...

How do you know? Have you seen what an oval design can do in the wind tunnel versus a narrowbody? Boeing has or is doing that right now. If the all knowing John Leahy is right and a clean sheet fuselage nets you 5% improvement, who's to say it has to be a single aisle that gets that 5% improvement?

william wrote:

How do you know? Have you seen what an oval design can do in the wind tunnel versus a narrowbody? Boeing has or is doing that right now. If the all knowing John Leahy is right and a clean sheet fuselage nets you 5% improvement, who's to say it has to be a single aisle that gets that 5% improvement?

1: nobody says a flat oval will bring you 5%
2: a twin aisle flat oval will incur 10+% penalty for the inefficient layout before you ever start to go for your projected 5% gains.

WIederling wrote:

william wrote:

How do you know? Have you seen what an oval design can do in the wind tunnel versus a narrowbody? Boeing has or is doing that right now. If the all knowing John Leahy is right and a clean sheet fuselage nets you 5% improvement, who's to say it has to be a single aisle that gets that 5% improvement?

1: nobody says a flat oval will bring you 5%
2: a twin aisle flat oval will incur 10+% penalty for the inefficient layout before you ever start to go for your projected 5% gains.

Again, HOW DO YOU KNOW? Could you for see the innovations Airbus debuted in the A350? Airlines and their and engineers have been given insight to Boeing's direction and it seems to have passed their BS meter.

What if Boeing really got aggressive? They seem committed to the 797 program, resource wise. But I haven't seen this scenario posited; they do announce 797 Mom (2 or 3 frame sizes at launch) this year. Concurrently, they also announce the 7007 NSA family, same cockpit, 2 sizes, different wings, to fly 2-3 years later.

If it's to be a family, why wait to 'recapture' with a 2-7 year later announcement. Make options/pricing available now, even if not firm. Oh, and also (preferably in advance), announce a partnership to market/support Embraer E2 globally. Flexible packaging with service/support including even interim 767 pax, or 737 MAX pricing, with conversion rights to the newer models. Boeing isn't known for aggressive/cutting edge sales strategies at all, other than their brief 'sole source' contract methodology, but it would be an interesting possibility, as they are working furiously to burn down the 737 backlog as quickly as possible, while expanding services.

william wrote:

WIederling wrote:

william wrote:

How do you know? Have you seen what an oval design can do in the wind tunnel versus a narrowbody? Boeing has or is doing that right now. If the all knowing John Leahy is right and a clean sheet fuselage nets you 5% improvement, who's to say it has to be a single aisle that gets that 5% improvement?

1: nobody says a flat oval will bring you 5%
2: a twin aisle flat oval will incur 10+% penalty for the inefficient layout before you ever start to go for your projected 5% gains.

Again, HOW DO YOU KNOW? Could you for see the innovations Airbus debuted in the A350? Airlines and their and engineers have been given insight to Boeing's direction and it seems to have passed their BS meter.

Contrary to popular belief engineering is not magic. one thing you learn early is to determine the parametric susceptibility of any design.
if you use a less efficient cabin layout you have to first bear the loss of efficiency from that. In the next step you can introduce the advantages of an oval fuselage. But the inefficient layout is not by magic inverted in its influence.

Barrels vs. panels: the panelvan approach has some advantages on its side vs the added complexities of Boeings barrels with co-cured stringers via a rather intricate mandrel that IMU the A350 had some advantage just from the design chosen.

JustSomeDood wrote:

Bernstein Research thinks Boeing will abandon the NMA, keeping the basic twin-aisle, ovoid concept but down-sizing the range from 4,500nm-5,000nm to no more than 4,000nm to become the 737 replacement.

There have been debates ad nauseum about whether the MoM should be a narrowbody or a widebody, and now Boeing would supposedly be able to make their widebody design deliver significantly better economics than the A320neo/738Max/CSeries? I find that hard to believe. Downsizing the range + size of the NMA puts it in the firing line of a A32x stretch/re-wing, which is what Boeing would want to avoid for their clean sheet...

Correct.

It'd be absolutely absurd to try and replace the 737 with a twin aisle. What is competitively passable at 240 seats, is suicide at 180 seats.

william wrote:

Again, HOW DO YOU KNOW? Could you for see the innovations Airbus debuted in the A350? Airlines and their and engineers have been given insight to Boeing's direction and it seems to have passed their BS meter.

What would airlines know about aircraft design? Surprisingly little. Too much is put on hype and bluster. Oh, and talk is cheap, putting money down on orders is a different story.

Re. the sizing, its a load of bull as anyone with some experience in the area will tell you.


A twin aisle *might* work at 250 seats (and I stress might), but if you are for replacing 737, then you need it to work at 200 seats. That, it simply won't do. Your finesse ratio is all wrong, even worse, it'll mean your tail volume ratio sizing is a horror show in terms of empennage size (=weight+drag).

texl1649 wrote:

What if Boeing really got aggressive? They seem committed to the 797 program, resource wise. But I haven't seen this scenario posited; they do announce 797 Mom (2 or 3 frame sizes at launch) this year. Concurrently, they also announce the 7007 NSA family, same cockpit, 2 sizes, different wings, to fly 2-3 years later.

If it's to be a family, why wait to 'recapture' with a 2-7 year later announcement. Make options/pricing available now, even if not firm. Oh, and also (preferably in advance), announce a partnership to market/support Embraer E2 globally. Flexible packaging with service/support including even interim 767 pax, or 737 MAX pricing, with conversion rights to the newer models. Boeing isn't known for aggressive/cutting edge sales strategies at all, other than their brief 'sole source' contract methodology, but it would be an interesting possibility, as they are working furiously to burn down the 737 backlog as quickly as possible, while expanding services.

I think the NSA and MOM are linked. But as been posted many times the power plants are not ready. Thats why I believe what Bernstein rumors about the 797 going lighter by offering less range and to be very competitive with the A321 or A322 (yes, Boeing can run simulations also).

The only question is the Embraer connection. How does it fit in this evolving puzzle?

texl1649 wrote:

What if Boeing really got aggressive? They seem committed to the 797 program, resource wise. But I haven't seen this scenario posited; they do announce 797 Mom (2 or 3 frame sizes at launch) this year. Concurrently, they also announce the 7007 NSA family, same cockpit, 2 sizes, different wings, to fly 2-3 years later.

That's no agressive. It is somewhere between unrealistic and magical.

Bernstein-Range.
Firstly I believe Boeing were talking about 5,000-5,500 nm don't recall the 4,500 number.But whether it is 4 or 4.5 (or something else) it doesn't tell nearly the whole story.
4,500nm could be with 3 act's.And what seating at that range?220-240?
Suddenly with no act's the range is well below these numbers.But v good payload.
And pax numbers at lower ranges.Does that then rise to 250-275 ?it's possible.
There is so much simple numbers in isolation don't tell you - and they are not going to tell you.

Jayafe wrote:

texl1649 wrote:

What if Boeing really got aggressive? They seem committed to the 797 program, resource wise. But I haven't seen this scenario posited; they do announce 797 Mom (2 or 3 frame sizes at launch) this year. Concurrently, they also announce the 7007 NSA family, same cockpit, 2 sizes, different wings, to fly 2-3 years later.

That's no agressive. It is somewhere between unrealistic and magical.

The B52 and 707 and 737 and 747 were all designed and flown in half that time. (7-9 years). The B36, much less.

Saw this on the web, similar to what has been rumored here. A321 all coach capacity is 240. What would a 797 potential all coach capacity be?

https://ibb.co/eOxM7G

I think 8Y is too wide. If the twin-aisle oval concept happens it will be a narrow 7Y, probably 1-1-1J with most products, and far closer to the A320 than the 767 in cross-section area. That will also solve the issue with an odd-shaped cargo hold.

The right all-coach capacity strikes me as 270 for the baseline and 305 for a ~5 row (4 m) straight stretch, at (marginally) more comfortable pitch than Airbus's 240-seat torture machine. Compare the 767-300ER and 787-8 at 375, and the A330-800 at 406.

texl1649 wrote:

Jayafe wrote:

texl1649 wrote:

What if Boeing really got aggressive? They seem committed to the 797 program, resource wise. But I haven't seen this scenario posited; they do announce 797 Mom (2 or 3 frame sizes at launch) this year. Concurrently, they also announce the 7007 NSA family, same cockpit, 2 sizes, different wings, to fly 2-3 years later.

That's no agressive. It is somewhere between unrealistic and magical.

The B52 and 707 and 737 and 747 were all designed and flown in half that time. (7-9 years). The B36, much less.

That was "the good old days". The sad fact (from an engineering / enthusiast point of view) is that the sector is now regulated and evolved to such an extent that even the tiniest innovation takes forever and a fortune to get designed / tested / certified. And that's before considering that the PowerPoint Rangers have taken over...

seabosdca wrote:

I think 8Y is too wide. If the twin-aisle oval concept happens it will be a narrow 7Y, probably 1-1-1J with most products, and far closer to the A320 than the 767 in cross-section area. That will also solve the issue with an odd-shaped cargo hold.

The right all-coach capacity strikes me as 270 for the baseline and 305 for a ~5 row (4 m) straight stretch, at (marginally) more comfortable pitch than Airbus's 240-seat torture machine. Compare the 767-300ER and 787-8 at 375, and the A330-800 at 406.

How do you fit an extra seat and extra aisle and stay very close to the A320 cross section? Taking an inch from each seat buys you 6 inches but you still need to add 11 inches to the A320 just for the extra seat then you need another aisle.

SomebodyInTLS wrote:

That was "the good old days". The sad fact (from an engineering / enthusiast point of view) is that the sector is now regulated and evolved to such an extent that even the tiniest innovation takes forever and a fortune to get designed / tested / certified. And that's before considering that the PowerPoint Rangers have taken over...

My current place of employ is a throwback to the days before things like Power Point and Microsoft Project and Rally ruled the roost. It's got other big problems, but no one seems to be willing or able to take them on. It seems relying on individual initiative and goodwill work out fairly well most of the time. It's kind of how civilization happened before MBAs were invented.

seabosdca wrote:

I think 8Y is too wide. If the twin-aisle oval concept happens it will be a narrow 7Y, probably 1-1-1J with most products, and far closer to the A320 than the 767 in cross-section area. That will also solve the issue with an odd-shaped cargo hold.

The right all-coach capacity strikes me as 270 for the baseline and 305 for a ~5 row (4 m) straight stretch, at (marginally) more comfortable pitch than Airbus's 240-seat torture machine. Compare the 767-300ER and 787-8 at 375, and the A330-800 at 406.

If you want to do this you are reaching a seat width that might be hard to sell to the public. You would need 16" seat with 15" aisles and if that is needed work the concept to work, I hope it does, because when innovation just means making the passenger more miserable, it is no innovation, because the next single aisle can make them just as miserable.

Revelation wrote:

SomebodyInTLS wrote:

That was "the good old days". The sad fact (from an engineering / enthusiast point of view) is that the sector is now regulated and evolved to such an extent that even the tiniest innovation takes forever and a fortune to get designed / tested / certified. And that's before considering that the PowerPoint Rangers have taken over...

My current place of employ is a throwback to the days before things like Power Point and Microsoft Project and Rally ruled the roost. It's got other big problems, but no one seems to be willing or able to take them on. It seems relying on individual initiative and goodwill work out fairly well most of the time. It's kind of how civilization happened before MBAs were invented.

And lawyers.

Don't ever forget to dump on the lawyers.


The ambulance chasers are largely responsible for the paperwork entropy that is bringing many public bodies to the brink of collapse.

planecane wrote:

How do you fit an extra seat and extra aisle and stay very close to the A320 cross section?

By not being any taller than the A320. My thought is that you'd have 7Y at 17.2" seats with 18" aisles. And I don't expect cross section would be the same as the A320, just much closer to A320 than 767 (which is much bigger than a 7Y aircraft needs to be even with a round fuselage).

Amiga500 wrote:

Revelation wrote:

SomebodyInTLS wrote:

That was "the good old days". The sad fact (from an engineering / enthusiast point of view) is that the sector is now regulated and evolved to such an extent that even the tiniest innovation takes forever and a fortune to get designed / tested / certified. And that's before considering that the PowerPoint Rangers have taken over...

My current place of employ is a throwback to the days before things like Power Point and Microsoft Project and Rally ruled the roost. It's got other big problems, but no one seems to be willing or able to take them on. It seems relying on individual initiative and goodwill work out fairly well most of the time. It's kind of how civilization happened before MBAs were invented.

And lawyers.

Don't ever forget to dump on the lawyers.

The ambulance chasers are largely responsible for the paperwork entropy that is bringing many public bodies to the brink of collapse.

Overall, I have to imagine the net impact of lawyers is negative, but threat of lawsuit is one of the things that makes the aviation industry take safety very seriously. Same can be said for many other things in aviation and other industries that the normal capitalistic urge for profit would relegate to the "maybe we'll do something about that someday" pile. The current computer security scare is a good example of this.

seabosdca wrote:

planecane wrote:

How do you fit an extra seat and extra aisle and stay very close to the A320 cross section?

By not being any taller than the A320. My thought is that you'd have 7Y at 17.2" seats with 18" aisles. And I don't expect cross section would be the same as the A320, just much closer to A320 than 767 (which is much bigger than a 7Y aircraft needs to be even with a round fuselage).

Wouldn't your 7Y idea need around 175" interior width? The 767 is 186" I believe and the A320 146" (if Wikipedia is correct). Therefore, your concept is 11" more narrow than the 767 but 29" wider than the A320.

To swag numbers this concept would be 20% wider than the A320 to hold 16.6% more seats per row. I guess for every 6 rows you can eliminate a row from the 6Y design. If you were to take the A321 capacity and make it 7Y it would shorten the A321 by around 160 inches. That would still make 9' or so longer than the A320.

I guess the question is, if you add 20% width to the A321 but remove 13' from the length what is the overall effect on drag and structural weight.

I used the A321 because it seems the 797 would have to have A321NEO economics or better to be a viable option for missions that the A321NEO can perform.

seabosdca wrote:

planecane wrote:

How do you fit an extra seat and extra aisle and stay very close to the A320 cross section?

By not being any taller than the A320. My thought is that you'd have 7Y at 17.2" seats with 18" aisles. And I don't expect cross section would be the same as the A320, just much closer to A320 than 767 (which is much bigger than a 7Y aircraft needs to be even with a round fuselage).

Something like this I guess.

https://ibb.co/eOxM7G

planecane wrote:

seabosdca wrote:

Wouldn't your 7Y idea need around 175" interior width? The 767 is 186" I believe and the A320 146" (if Wikipedia is correct). Therefore, your concept is 11" more narrow than the 767 but 29" wider than the A320.

Depends on armrest width (which I elided) but, yes, that's about right. But let's do some math that includes height. The 767 is a seriously tall airplane and this contributes to much of its excess cross-section area

Fuselage cross-section area (including exterior walls, but ignoring "double bubble" imperfections in ellipse shape):
737NG/MAX 18365 in^2 (158"h, 148"w)
A32S ~20086 in^2 (163"h, 155"w)
NMA (my concept) ~23521 in^2 (164"h, 183"w)
767 ~32621 in^2 (213"h, 195"w)

So compared with the A320 we're adding 17% cross sectional area for 17% seats.

seabosdca wrote:

I think 8Y is too wide.

Not really. This has be covered many times in this thread. If we are talking an oval design when looking side on the 8ab will look extremely slim as the height will be fairly low.

From a strength and aircraft loading perspective having a taller fuselage than it is wide is beneficial. A fuselage that is wider than it is high is structurally poor and will require a lot of extra strengthening. So it will have to be fairly short and stubby when looking from the top.

In addition fineness ratio isn't that important. The 8ab would still be within the acceptable fineness ratio range with the 270-300 seats. The 7ab may be a percent better from a fineness ratio and drag perspective. It would be no thicker than a A380, 762 or A320.

The 7ab has one big disadvantage. It is much worse from a seating area perspective. The minimum aisle size is 15". So two 15" aisles is 30" aisle space.

Baseline A320 has one 22" aisle for 6 seats

7ab has 30" of aisle for 7 seats
That is 36% more aisle for only 16.6% more seats.

8ab has 30" of aisle for 8 seats
That is 36% more aisle for 33.3% more seats.

This is a big deal that pretty much guarantees an 8AB cabin even if its a little short and stubby. It definitely can't be 6ab as it would need to be longer than a 757-300.

seabosdca wrote:

planecane wrote:

seabosdca wrote:

Wouldn't your 7Y idea need around 175" interior width? The 767 is 186" I believe and the A320 146" (if Wikipedia is correct). Therefore, your concept is 11" more narrow than the 767 but 29" wider than the A320.

Depends on armrest width (which I elided) but, yes, that's about right. But let's do some math that includes height. The 767 is a seriously tall airplane and this contributes to much of its excess cross-section area

Fuselage cross-section area (including exterior walls, but ignoring "double bubble" imperfections in ellipse shape):
737NG/MAX 18365 in^2 (158"h, 148"w)
A32S ~20086 in^2 (163"h, 155"w)
NMA (my concept) ~23521 in^2 (164"h, 183"w)
767 ~32621 in^2 (213"h, 195"w)

So compared with the A320 we're adding 17% cross sectional area for 17% seats.

How would you do this.

The aisles are off-set from centre on the NMA concept and the plane is about 25" wider. The lower section bubble height is determined by the the LD3/45 so it will be a wash, so it must all be found in the upper bubble which imho requires a complex shape and won´t work with part circle or an ovid shape. But that means complex construction and challenging load bearing.

seahawk wrote:

How would you do this.

The aisles are off-set from centre on the NMA concept and the plane is about 25" wider. The lower section bubble height is determined by the the LD3/45 so it will be a wash, so it must all be found in the upper bubble which imho requires a complex shape and won´t work with part circle or an ovid shape. But that means complex construction and challenging load bearing.

Both lower and upper bubbles would be close to the same height as those of the A320 (I'd expect upper bubble a tiny bit taller).

You're absolutely right; it would be a complex shape. I think whether such a shape can be built economically and at a roughly proportional weight using CFRP is the key question that determines whether twin-aisle NMA is viable. A simpler, larger-area 767-style shape (to say nothing of a 767 MAX) would get killed on operating economics.

Compare the weight and costs to that to a 3-3 at 18 inch wide seats decent 2 inch armrest and a spacey 30 inch aisle, circular but a 17% longer fuselage. In terms of passenger comfort, passenger/crew movements I think it would be better for longer flights. Better and cheaper than ultra narrow seats and aisles. I avoid aisle seats on 9 abreast 787s and 10 abreast 777s. For good reason.

IMO ovoid fuselages are a big red herring.

Forcing the pressurized tube into some non-circular cross section will require extra strong frames, that will destroy any gains because of added weight.

Trading between wasted-fuselage-lobe-due-to-circular-fuselage and heavy-structure-due-to-ovoid-fuselage in the past always the former has won. Also in two CFRP designs. If it would be so beneficial (or even possible) to go for ovoid fuselages, then why wasn't it done for 777, 787, A350 and the likes? I fear a proper trade off will not change in the future, how it was done in the past (e.g. nobody would have stopped Airbus from cutting off the wasted fuselage lobe of the A350 if the overall trade off would have been beneficial).

What many here seem to ignore (or at least underestimate) is the negative impact of an ovoid fuselage. It must be huge. There is far too much focus on seats/cross-section-area or fuselage surface (speak the aerodynamic side). How about weight and simplicity of the design?

NB-economics with a WB will not work. Lots of wrong comparisons are made in this thread (like comparing ovoid WBs with non-ovoid NBs, 8-abreast 767 with NBs, 9-abreast A310 with NBs) to make the numbers work.

Ovid is possible from a construction perspective, but it only is efficient if you look at the width at floor height. If you move it to shoulder height, it is inefficient by nearly definition. In end you would need a complex frame with rather little curvature on the side and a nearly flat roof section.More a rounded rectangle than an ovid. And this is very challenging for a pressure vessel.

With CFRPs it can be done, but it will be a bit heavier than a double bubble or A350/787 like fuselage. It becomes a big challenge if you want to do this complex CFRP structure out of autoclave and with reduced production costs. Doable yes, but with a huge risk in design, development and maturing production technology. (risk meaning delays and cost overruns)

The only reason anybody is discussing an ovoid fuselage at X7 is because this is what all the editorial on the Boeing MOM suggests it will be.
I fully appreciate Boeing don't have a clue about aircraft and after reading this and many other threads will realise their elementary mistakes.

Revelation wrote:

Overall, I have to imagine the net impact of lawyers is negative, but threat of lawsuit is one of the things that makes the aviation industry take safety very seriously.

I wouldn't wholly agree with that.

The lawsuit of an aircraft would swallow a year or two of profits, while that is bad for the wall street idiots, it in itself likely wouldn't mean much to the long term security of the airframer. After all, look at the write-downs they are able to swallow on development programs gone wrong!

However, if people lost confidence in the safety of commercial aviation and moved to other modes of transport, then the airframers would be in a bad way.

RJMAZ wrote:

From a strength and aircraft loading perspective having a taller fuselage than it is wide is beneficial. A fuselage that is wider than it is high is structurally poor and will require a lot of extra strengthening. So it will have to be fairly short and stubby when looking from the top.

Worse than that, its also poor from a pressure loading perspective. The floor beams would be in compression - to prevent buckling they'd need to be much heavier than the circular fuse equivalent.

Yet, all that added weight would do nothing for you to relieve stress from vertical - as its all too close to the neutral axis of the fuselage.

parapente wrote:

The only reason anybody is discussing an ovoid fuselage at X7 is because this is what all the editorial on the Boeing MOM suggests it will be.
I fully appreciate Boeing don't have a clue about aircraft and after reading this and many other threads will realise their elementary mistakes.

I think there's good reason Boeing didn't go for an horizontal ovoid fuselage over the last 70 years. Mechanics haven't been reinvented since then & weight is still kind of crucial for efficiency. Many cross sections today are not exactly circular. A320, 787 come close. If you stay close to circular induced loads stay under control. Higher fuselages are best from a flight loads perspective. Hence the double bubbles from e.g. 737 and 767.

This thread has officially become a bad replay of every other MOM/NMA thread we've ever had here.

Sometimes I wonder why people bother typing in the same stuff over and over again, but then again sometimes I find myself doing it too.

Cest la vie.

Now, more discussion about containers!

Amiga500 wrote:

I wouldn't wholly agree with that.

The lawsuit of an aircraft would swallow a year or two of profits, while that is bad for the wall street idiots, it in itself likely wouldn't mean much to the long term security of the airframer. After all, look at the write-downs they are able to swallow on development programs gone wrong!

However, if people lost confidence in the safety of commercial aviation and moved to other modes of transport, then the airframers would be in a bad way.

Sure, loss of confidence in the industry is the worse fear, but IMHO exposure to lawsuits is one of the few triggers for "drop everything" moments I've seen in my corporate lifetime spanning three decades now.

I'm reminded of this as we see a wave of computer security flaws being revealed, since that was a focus of mine on one of my previous projects.

Revelation wrote:

This thread has officially become a bad replay of every other MOM/NMA thread we've ever had here.

Sometimes I wonder why people bother typing in the same stuff over and over again, but then again sometimes I find myself doing it too.

Cest la vie.

Now, more discussion about containers!

Talking about containers is fun. Keesje and RJMAZ have posted more or less the same cross sectional photos showing containers 7 times in this thread. Since not much has come out, let's continue talking about cross sections.../sarcasm.

Wake me up when some real information on the plane comes out again. I want to know more about the airplane and its development, so I do keep reading the thread, but just find the same old tired discussion about extra wide aisles or inefficiencies of 7 abreast planes, etc.

Boeing are never going to publicly say what everyone knows.Thats ok one would not expect them to.Just like Airbus saying that the 338 is a perfect mom a/c.Of course it's total BS but I would not expect them to say otherwise.
Boeing have a problem and its increasing by the day as the market moves upwards in (narrowbody) size.
Their 180-200 offering -The 8, is just fine for what it has to do and the 7 is there for those that need a 150-175 ac.
But above that...The 9 is rubbish and has had to be replaced.But the 10 is engineering by sellotape.
It's t/o performance will be better but not great.It is larger than the 9 but still too small and it is Range limited.

On present sales the A321NEO is not the top of the 320 range it's now the middle and everyone knows they can stretch to a 250+ with or without a new wing - or a brand new engine.So Boeing have to do something.
So no surprises that their so called MOM is designed to take between 220 and 270 pax.Who would argue with that?
No surprises is a twin aisle -ever tried getting off a 753 or a fully loaded A321?
Clearly the use of carbon composites (and mandril) has allowed them new physical opportunities that were never existed before - hence slapping down a patent for the oval section.
But they know this a/c must compete with the A321NEO and any 322.Hence the push for aero efficiency as best they can (X7)

What (it seems to me) is the biggest question and one which some journalists have strongly questioned is - range.
Range (or excessive range) causes a truly vicious circle (wing/engine/MLG and weight -the real killer).
Boeing have been talking up to five and a half thousand nautical miles! Notable journalists have questioned this stating 4knm is all that is required.Personally I think 4.5knm would be (with acts)fine.
In truth this aircraft would replace the 739,7310,752 and (just) 573.It would also replace (some of) the 767 but be range constrained.
At 5knm +the 788 works just fine and many airlines are already doing just that with theirs (and in some cases ordering more).
It's a better,more modern,more economical aircraft than the 338 and always will be.Thats Airbus' problem for the future not theirs!

parapente wrote:

Boeing are never going to publicly say what everyone knows.Thats ok one would not expect them to.Just like Airbus saying that the 338 is a perfect mom a/c.Of course it's total BS but I would not expect them to say otherwise.
Boeing have a problem and its increasing by the day as the market moves upwards in (narrowbody) size.
Their 180-200 offering -The 8, is just fine for what it has to do and the 7 is there for those that need a 150-175 ac.
But above that...The 9 is rubbish and has had to be replaced.But the 10 is engineering by sellotape.
It's t/o performance will be better but not great.It is larger than the 9 but still too small and it is Range limited.

If these are Boeing's problems, then they are good ones to have.

Despite your opinions of the 737 product line, the production line is full for the foreseeable future.

Customers think enough of those 'rubbish' -9s and 'cellotape' -10s to spend $BILLIONS to buy them.

Having the market size move upwards is not a problem for Boeing, it's an opportunity.

In fact it's the opportunity that would help them launch the NMA/MOM product.

Having the market size move upwards is a problem for Bombardier.

Design it for 4.5K to start and overtime (by mid 2030's) I'm sure with PIP's and optimization it will grow to be a 5.5K aircraft.

They have to think about how the aircraft will evolve over time. If they start at 5.5k it will end up being a 6.5-7.0k frame in 15-20 years from EIS.

morrisond wrote:

Design it for 4.5K to start and overtime (by mid 2030's) I'm sure with PIP's and optimization it will grow to be a 5.5K aircraft.

They have to think about how the aircraft will evolve over time. If they start at 5.5k it will end up being a 6.5-7.0k frame in 15-20 years from EIS.

Yes, pretty much the 777X problem in a nutshell. What was intended as a DC-10/MD-11 replacement just kept growing and now it's being attacked from below by A350.

I agree 4.5K is the right target. Much more than that risks making it too big for its intended roles.