I seem to remember LH said they could not. This is why LH didn't use the 757-300any longer. They had ordered too many.

CRJockey wrote:

FluidFlow wrote:

morrisond wrote:

But a tight light 2 class 2x3x2 does not have more volume than a 3x3 when you adjust for similar capacity. The 2x3x2 actually has about 9% less skin and 2% less internal volume - that extra seat being basically in the bulge is a very efficient cost in volume - basically the decrease in length of the cabin more than offsets the increased width of a tight 2x3x2.. The penalty in aisle space is only about 1.4x for two 17" aisles vs one 19" aisle.

Boeing is calling it a 2 Class aircraft (according the AVWeek article). I think Boeing is seeing the writing on the wall and they know by the time this aircraft arrives COMAC could be a major player. They will have a very hard time competing with them for airlines that are all Y or Y-. An all Y NMA has about 1% less Skin and 6.5% more internal volume. They need to differentiate themselves as Calhoun has stated.

A 168x183" cross section gets you containers than can carry about 50% more than an LD3-45 offset by the reduced cabin length - so probably about 20-25% more cargo capacity than the 3x3.

So you compromise the optimal shape (now a sphere is the perfect shape, but for an aircraft it is more or less a circle) to not gain any volume just to have an aisle? Why would you do that if you no not want more seats? So if you aim at the same capacity then you do not need any special shape. The point is, that if you compare a 240 seats circle with a 240 seats ovoid (or whatever weird shape you go for), you only add complexity without any additional capacity. This does not help the case. To make it worth while you need to increase capacity what also needs more MTOW, what makes the design heavier.

And for the containers:
If it does not take LD3-45s it is dead in the water. There are billions invested in automated cargo systems that take LD3-45 (or the wide body version of the LD3 and LD2 containers). So no one will accept different shapes and sizes just because Boeing builds a strange shaped pax aircraft.
That means the shorter cabin would lead to actually less cargo capacity because you can carry less containers.
The only other option would than be to bulk load to use the wider cargo bay but that would make turn around times horrible because bulk loading long haul operations where we have more checked luggage would be a nightmare (operational).

You excellently put in writing why I can't really get a grip of this thread.

Seemingly design decisions are thrown around as if suddenly typical constraints of tube & wing, aluminum and / or CFRP have materially changed.
Suddenly stubby planes are shown to be a good solution, when they traditionally have been awful from a revenue potential vs. cost perspective.
Suddenly comfort is a thing again, when neither the industry, nor the most important average consumer has shown any appetite to pay real cash for any amount of comfort improvement. Nobody in the real world is paying a dime more to fly A320 vs. 737, or A350 vs. 787 to gain an inch of seat width.
Suddenly we are advocating complex forms, disregarding basic requirements of material load distribution patterns or talking them down as being mitigated by "new materials". And those same complex forms are now suddenly heavily 3D-printed on a large industrial scale to not only enable those very forms, but to also bring production cost down so significantly, that it shall be one of the most important competitive advantages of the new plane.
And at the same time, we advocate using new, non-compatible containers or go back to the future via bulk loading.

I have my doubts.

Its human psychology; New/innovative ideas are exiting, rehashes of old ideas are safe and boring.

I still believe an narrower single aisle with an smaller than LD3-45 container is the only way to outperform the A321 and hypothetical A322 on all stages and steal significant sales. OEW of -5-10% will have an massive impact and can't be replicated easily...

FluidFlow wrote:

morrisond wrote:

FluidFlow wrote:

The thing is, you can not have single aisle operating cost with two aisle. That is physically not possible. Under the assumption you have all the tech available and can choose your product, the moment one gets bigger than the other you need more material, what makes the frame heavier, what leads to bigger wings and engines, what makes the frame heavier, what leads to stronger gears, what makes the frame heavier, etc.

So from the moment you add volume you also add weight. Now of course the additional volume allows for additional seats to spread the cost, but your operational costs will be higher.
So an empty 2-3-2 aircraft will be more expensive to fly than an empty 3-3 aircraft if both are at the same tech level.

If the 2-3-2 should fly further then it will be even more at a disadvantage on direct competing routes.

Now if one thinks you can overcome that with an aircraft designed towards pure pax operation and just design as much cargo hold away as possible, that will make up a bit but it also reduces the sales potential in certain regions.

There is a reason that no aircraft sits between the A321 and 787-8 in size and even there the 787-8 is suboptimal. Regulations on seating configurations just make dead space super expensive to build for no gain thats why 3-4-3>3-3-3>2-4-2>2-3-2. Also everything that can not take the containers avialable now is by design a failure. Cargo will not change, not for decades. We still use the same containers on ships as ever (thats how it seams, it is that long), and they fit on trucks as well. Same goes for Airfreight. The system is so interconnected, you can not move away from it anymore.

But a tight light 2 class 2x3x2 does not have more volume than a 3x3 when you adjust for similar capacity. The 2x3x2 actually has about 9% less skin and 2% less internal volume - that extra seat being basically in the bulge is a very efficient cost in volume - basically the decrease in length of the cabin more than offsets the increased width of a tight 2x3x2.. The penalty in aisle space is only about 1.4x for two 17" aisles vs one 19" aisle.

Boeing is calling it a 2 Class aircraft (according the AVWeek article). I think Boeing is seeing the writing on the wall and they know by the time this aircraft arrives COMAC could be a major player. They will have a very hard time competing with them for airlines that are all Y or Y-. An all Y NMA has about 1% less Skin and 6.5% more internal volume. They need to differentiate themselves as Calhoun has stated.

A 168x183" cross section gets you containers than can carry about 50% more than an LD3-45 offset by the reduced cabin length - so probably about 20-25% more cargo capacity than the 3x3.

So you compromise the optimal shape (now a sphere is the perfect shape, but for an aircraft it is more or less a circle) to not gain any volume just to have an aisle? Why would you do that if you no not want more seats? So if you aim at the same capacity then you do not need any special shape. The point is, that if you compare a 240 seats circle with a 240 seats ovoid (or whatever weird shape you go for), you only add complexity without any additional capacity. This does not help the case. To make it worth while you need to increase capacity what also needs more MTOW, what makes the design heavier.

And for the containers:
If it does not take LD3-45s it is dead in the water. There are billions invested in automated cargo systems that take LD3-45 (or the wide body version of the LD3 and LD2 containers). So no one will accept different shapes and sizes just because Boeing builds a strange shaped pax aircraft.
That means the shorter cabin would lead to actually less cargo capacity because you can carry less containers.
The only other option would than be to bulk load to use the wider cargo bay but that would make turn around times horrible because bulk loading long haul operations where we have more checked luggage would be a nightmare (operational).

This is really making me laugh. So I show that you basically get that extra aisle for more than free (in terms of Volume and skin area) and somehow that is a negative?

As most of the production will be automated - more complex parts won't really add that much more cost.

The point of this cross section - as others have pointed out above is that it could be the cross section for NSA as well and range up to 300 seats. It also differentiates Boeing as the premium product against COMAC which will be a much larger threat by EIS and Airbus if they do not go clean sheet (and they could easily do something like this 2x3x2 and would have more room to do so given they have the A220 - then they have 5W, 7W and 9W assuming A330 death - which is perfect).

For the container size the market will adapt - as others have pointed out many of there existing 737 Customers do not have the cargo handling equipment yet anyways - if the Cross section is also used for NSA then you are talking about an installed base of easily over 10,000 frames in the 2030's and 2040's. Some more Cargo Handling equipment won't be an issue. No reason you won't be able to put an LD3-45 in it either. - Less Capacity - but packed full for LR missions you might be Cargo limited anyways. Short Haul you don't need that much space in the belly.

In any case a new Container is not a show stopper.

WIederling wrote:

FluidFlow wrote:

And for the containers:
If it does not take LD3-45s it is dead in the water. There are billions invested in automated cargo systems that take LD3-45 (or the wide body version of the LD3 and LD2 containers). So no one will accept different shapes and sizes just because Boeing builds a strange shaped pax aircraft.

Difficult to say.
If Boeing manages to convert their 737 bulk loading customers to containerized they might be able to introduce a new form factor.
compare the 767: it introduced the LD2/LD8 box afair ( where the A300 fit an existing box:LD3), a new box style.

Airbus NB introduced the LD3-45 type an adaption of the basic LD3. essentially a new type too.

All taken a new type or not may be dependent on the market Oompf Boeing can excert.

Actually, thinking a bit more on it, a new container could be a key to success for a new Boeing 3x3 cross section. If Boeing would be able to enforce a new container, they might be able to do quite the coop. Their chances of succeeding at such would be an order of magnitude bigger with a single 3x3 cross section compared to having different fuselage cross sections for NMA and NSA. If they were able to launch a lower and wider container than the LD3-43, that would open up a whole avenue of opportunity for them against the A320 (and less important the MC-21 as well). Possibly enough advantage to be able to survive through the ramp up face against a 60+/month A320 rate.

If they would be able to enforce a lower and wider container, combined with a circular MC-21 sized 3x3 cross section, they would be able to lower the floor and thus hugely increase the available headspace. That could mean that, based on the 4.06 m MC-21 diameter (again identical circumference/wetted area as the A320) the width of the cabin at head height could be about 13 cm / 5'' wider than the A320 with practically the same wetted area. That means that you can do 74 cm / 29” aisle with 737/787 seat width (at seat height it would even be about 15 cm / 6’’ wider). On top of that one would make better use of the cargo part of the cross section with less dead space.





If Boeing would be able to pull that off, they might even put the A320 in trouble. The MC-21 would not be able to do the same because it's floor is already fixed in design to serve LD3-45. They didn't have the cloud to do the same trick Boeing might be able to do. It would have an around 30 cm / 12'' wider and much taller cabin than the 757, providing a completely different medium haul cabin experience.

You can´t go smaller than the 737 and even there the OEW difference ins negligible. I personally think the whole debate about the fuselage diameter is missing the main problems. A few centimetres more or less, have less influence on the OEW than 500nm range more or less.
In the end plane design still is quite simple. I want to fly X passengers and Y tons of cargo over a distance of Z. The rest comes nearly by itself once you have this and have an idea on the available engine and their expected fuel burn.

CRJockey wrote:

brindabella wrote:

seahawk wrote:

A 6 abreast would never have the same capacity without being too long. It also has an inferior product with 100% more middle seats. Boeing needs to be daring and I think airlines are really wanting the MOM.

Indeed.
I haven't seen it quoted for quite some years however BA themselves used to say that they had learned their lesson from the 757-300 - "it was just too long"
(This is for RPT of course - the 753 seemed to work extremely well for non-sked Ops).

I joined an airline circa 1990 which was a very satisfied 767 operator.

When I queried why they had never used the 757, the answer was:

"Uneconomic. Carries 30-40 fewer passengers than the 767 but takes as long - OR LONGER to turn around".

Which is exactly the space into which an A322 would launch, as far as I can see.

cheers

.

You make a good point in general, I am just not sure how applicable it is in the MOM context.

Turn around times are less and less important the longer your average stage length gets. Lets be clear here, MOM won't be flying JFK - MIA, LHR - FRA or MAD - WAW anymore than todays large widebodies do. MOM will be flying MAN - PHL, MUC - PHX and the likes. Turn times won't be deal breakers here, as intercont flying has an inherent disadvantage in A/C usage during 24h to hit preferential departure times for consumers. If the 753 had reliable 5000NM over ground range even in unfavorable winds, it would be far more a plane busting hubs than 787 ever was. Not that I believe in busting hubs...

However a future NSA with the same cross section but smaller wing/wingbox/tail and engines and equivalent to 322+ plus in size will be flying JFK-MIA and turn times could be very important.

Right now we are at about 170-180 seat (2-class) average Capacity on SA in the developed markets for new aircraft coming off the lines - many Airports are slot constrained now when times are normal. With passenger growth of 2-3% per annum after Covid lifts - by 2035-2040 - only 5-10 years from potential NSA EIS of no earlier than 2030 - the optimal aircraft may be 250 seats - where a 3x3 won't really work.

Even an 2 row longer A322 will only seat about 200-210 in 2 class. Heck - thinking about it an NMA could be used on those trunk routes for if the initial version is about A322 realistic 2 class capacity of about 200-210 and 5,000 NM range - going to 250 2 class could reduce range down into the 3,000's which would not be abusing it that much.

You would still need an NSA for shorter/non slot constrained stuff though or build a really large NSA - but NMA could be a lot larger part of the market in the future than we are assuming.

Again, some are too focused on capacity vs. market. If a smaller plane with the same range can serve the same market because it can offset it's smaller size with way lower costs (variable as well as acquisition cost) the market will be well served. If you have a 3x3 that can do 5.200 Nm, it does not have to seat widebody capacity, because it will be so cheap it doesn't matter for the vast majority of missions.

Taxi645 wrote:

WIederling wrote:

FluidFlow wrote:

And for the containers:
If it does not take LD3-45s it is dead in the water. There are billions invested in automated cargo systems that take LD3-45 (or the wide body version of the LD3 and LD2 containers). So no one will accept different shapes and sizes just because Boeing builds a strange shaped pax aircraft.

Difficult to say.
If Boeing manages to convert their 737 bulk loading customers to containerized they might be able to introduce a new form factor.
compare the 767: it introduced the LD2/LD8 box afair ( where the A300 fit an existing box:LD3), a new box style.

Airbus NB introduced the LD3-45 type an adaption of the basic LD3. essentially a new type too.

All taken a new type or not may be dependent on the market Oompf Boeing can excert.

Actually, thinking a bit more on it, a new container could be a key to success for a new Boeing 3x3 cross section. If Boeing would be able to enforce a new container, they might be able to do quite the coop. Their chances of succeeding at such would be an order of magnitude bigger with a single 3x3 cross section compared to having different fuselage cross sections for NMA and NSA. If they were able to launch a lower and wider container than the LD3-43, that would open up a whole avenue of opportunity for them against the A320 (and less important the MC-21 as well). Possibly enough advantage to be able to survive through the ramp up face against a 60+/month A320 rate.

If they would be able to enforce a lower and wider container, combined with a circular MC-21 sized 3x3 cross section, they would be able to lower the floor and thus hugely increase the available headspace. That could mean that, based on the 4.06 m MC-21 diameter (again identical circumference/wetted area as the A320) the width of the cabin at head height could be about 13 cm / 5'' wider than the A320 with practically the same wetted area. That means that you can do 74 cm / 29” aisle with 737/787 seat width (at seat height it would even be about 15 cm / 6’’ wider). On top of that one would make better use of the cargo part of the cross section with less dead space.





If Boeing would be able to pull that off, they might even put the A320 in trouble. The MC-21 would not be able to do the same because it's floor is already fixed in design to serve LD3-45. They didn't have the cloud to do the same trick Boeing might be able to do. It would have an around 30 cm / 12'' wider and much taller cabin than the 757, providing a completely different medium haul cabin experience.

Neat idea - but I doubt that a wider container would be lower. I'm assuming for an NMA it's about 30" wider (in the largest part) but probably keeping the same height - maybe a few inches higher - but keeping the same height would make it more common with LD3-45.

Funny thing when you do the math on a 2x3x2 with two 17" Aisles (Only 1" less than 777X) vs a 3x3 of the same capacity - due to the 2x3x2 being shorter the aisle area floor penalty is only about 40% - and equivalent to an 27" aisle in a 3x3. That is a no-brainer trade - any airline would take the 2 aisle for a lot better turnover and circulation in the cabin.

Taxi645 wrote:

Again, some are too focused on capacity vs. market. If a smaller plane with the same range can serve the same market because it can offset it's smaller size with way lower costs (variable as well as acquisition cost) the market will be well served. If you have a 3x3 that can do 5.200 Nm, it does not have to seat widebody capacity, because it will be so cheap it doesn't matter for the vast majority of missions.

You are not going to use a 150 seat aircraft on JFK-MIA in 2040 - where will you get the slots?

morrisond wrote:

Taxi645 wrote:

WIederling wrote:

Difficult to say.
If Boeing manages to convert their 737 bulk loading customers to containerized they might be able to introduce a new form factor.
compare the 767: it introduced the LD2/LD8 box afair ( where the A300 fit an existing box:LD3), a new box style.

Airbus NB introduced the LD3-45 type an adaption of the basic LD3. essentially a new type too.

All taken a new type or not may be dependent on the market Oompf Boeing can excert.

Actually, thinking a bit more on it, a new container could be a key to success for a new Boeing 3x3 cross section. If Boeing would be able to enforce a new container, they might be able to do quite the coop. Their chances of succeeding at such would be an order of magnitude bigger with a single 3x3 cross section compared to having different fuselage cross sections for NMA and NSA. If they were able to launch a lower and wider container than the LD3-43, that would open up a whole avenue of opportunity for them against the A320 (and less important the MC-21 as well). Possibly enough advantage to be able to survive through the ramp up face against a 60+/month A320 rate.

If they would be able to enforce a lower and wider container, combined with a circular MC-21 sized 3x3 cross section, they would be able to lower the floor and thus hugely increase the available headspace. That could mean that, based on the 4.06 m MC-21 diameter (again identical circumference/wetted area as the A320) the width of the cabin at head height could be about 13 cm / 5'' wider than the A320 with practically the same wetted area. That means that you can do 74 cm / 29” aisle with 737/787 seat width (at seat height it would even be about 15 cm / 6’’ wider). On top of that one would make better use of the cargo part of the cross section with less dead space.





If Boeing would be able to pull that off, they might even put the A320 in trouble. The MC-21 would not be able to do the same because it's floor is already fixed in design to serve LD3-45. They didn't have the cloud to do the same trick Boeing might be able to do. It would have an around 30 cm / 12'' wider and much taller cabin than the 757, providing a completely different medium haul cabin experience.

Neat idea - but I doubt that a wider container would be lower. I'm assuming for an NMA it's about 30" wider (in the largest part) but probably keeping the same height - maybe a few inches higher - but keeping the same height would make it more common with LD3-45.

Funny thing when you do the math on a 2x3x2 with two 17" Aisles (Only 1" less than 777X) vs a 3x3 of the same capacity - due to the 2x3x2 being shorter the aisle area floor penalty is only about 40% - and equivalent to an 27" aisle in a 3x3. That is a no-brainer trade - any airline would take the 2 aisle for a lot better turnover and circulation in the cabin.

What you're missing is this would provide a 74 cm / 29'' aisle and have 100% cross section commonality between NSA and NMA. No one is going to want 2x 17'' aisle if you can have practically the same boarding speed and much more comfort flexibility with a cabin that can offer one 29'' aisle and has 100% cross section commonality with NSA and the same wetted area as an A320.

morrisond wrote:

Taxi645 wrote:

Again, some are too focused on capacity vs. market. If a smaller plane with the same range can serve the same market because it can offset it's smaller size with way lower costs (variable as well as acquisition cost) the market will be well served. If you have a 3x3 that can do 5.200 Nm, it does not have to seat widebody capacity, because it will be so cheap it doesn't matter for the vast majority of missions.

You are not going to use a 150 seat aircraft on JFK-MIA in 2040 - where will you get the slots?

"because it will be so cheap it doesn't matter for the vast majority of missions."

Who is talking about 150 seats? A ~50m 3x3 would be sufficient.

JonesNL wrote:

Well, it can become really elegant if they introduce an single aisle NMA, which later can be downscaled to an NSA with a different wingbox, wing and tail. This way they have 1 cockpit, tube and production method for the 150-300 seat segment.

Yes - so why didn't Boeing do that?

It should have been pretty easy to design a new airframe drawing from the 757-200 and 757-300 with new engines and a new wing and a slightly wider fuselage. Scale it at 250 and 300 seats with an MTOW high enough to tank a fair bit of fuel to give it up to a 5000nm range.

My primary guess is that airlines did not like the planned turnaround times for such a long frame (47-57m) as almost all "mainline" carriers worldwide use single jet bridges. Hence all the talk about using twin aisles and a shorter fuselage length - the 767-200 carries as many people as the 757-300, but in a cabin 6 meters shorter.

morrisond wrote:

Taxi645 wrote:

Again, some are too focused on capacity vs. market. If a smaller plane with the same range can serve the same market because it can offset it's smaller size with way lower costs (variable as well as acquisition cost) the market will be well served. If you have a 3x3 that can do 5.200 Nm, it does not have to seat widebody capacity, because it will be so cheap it doesn't matter for the vast majority of missions.

You are not going to use a 150 seat aircraft on JFK-MIA in 2040 - where will you get the slots?

When in 2019 regional jets have been a substantial part of JFK flying, I see no reason that in 2040 aircraft in the size range of 150 seats will find a slot.

morrisond wrote:

However a future NSA with the same cross section but smaller wing/wingbox/tail and engines and equivalent to 322+ plus in size will be flying JFK-MIA and turn times could be very important.

I always thought the US is so frequency driven? No, not even in 2040 will MIA - JFK be flown by 15-20 daily frequencies with 250 seats.

MOM is a transatlantic, transcontinental tool. MOM will be abused, like so many other planes, for shorter trunk routes on some rare occasions. It will not be built for those occasions.

I agree with Market/Route has to be the focus. I'm not sure I understand the obsession with 5000nm+ distances...

4000nm gets you from Frankfurt Germany to Atlanta Georgia.

4300nm gets you from London to Calcutta, or Miami to Hawaii, or Halifax to Mexico City

5000nm gets you from Manchester to Johannesburgh, Istanbul to Tokyo

5200nm gets you Oslo to Pratoria

These are really long flights... exagerrated a bit.... Why does the NMA/NSA need to approach such long distances? With all that capability it will be rather comprimised for uhhhhh, middle of the market missions, no?

Do we really need to fly this far with just 250 people? Is this really the Market? Even a A321XLR is not going to fly any more than 200pax to 4500nm.. or 240pax to 4000nm... under the best of conditions.

The only thing Calhoun said that we can glean anything meaningful from is they were attacking the A321XLR family....... That gives us mission profile of 200-240pax 3500 to 4500nm.... and I don't know if you go after the niche 4500nm... that's what you have 788,789,7810 for.... (or you cede the handful of missions where carriers think they fly 200pax to 4500nm profitably to the A321XLR)

Universally, once you start going over 4000nm you are on a different continent from where you started (the Halifax to Mexico City was an extreme example where you actually stay on the same continent).

If you make NMA/NSA too capable and you leave MAX to serve the lower market and continuing to loose to A321 at 200-240pax < 2500nm missions (yes... MAX8 excells below 180pax... but that's not the weakness... and there were probably many times an A321neo/lr/xlr was selected over the MAX8... backlogs reflect that is probably the case)....

anyway, just thoughts...

FiscAutTecGarte wrote:

I agree with Market/Route has to be the focus. I'm not sure I understand the obsession with 5000nm+ distances...

4000nm gets you from Frankfurt Germany to Atlanta Georgia.

4300nm gets you from London to Calcutta, or Miami to Hawaii, or Halifax to Mexico City

5000nm gets you from Manchester to Johannesburgh, Istanbul to Tokyo

5200nm gets you Oslo to Pratoria

These are really long flights... exagerrated a bit.... Why does the NMA/NSA need to approach such long distances? With all that capability it will be rather comprimised for uhhhhh, middle of the market missions, no?

Do we really need to fly this far with just 250 people? Is this really the Market? Even a A321XLR is not going to fly any more than 200pax to 4500nm.. or 240pax to 4000nm... under the best of conditions.

The only thing Calhoun said that we can glean anything meaningful from is they were attacking the A321XLR family....... That gives us mission profile of 200-240pax 3500 to 4500nm.... and I don't know if you go after the niche 4500nm... that's what you have 788,789,7810 for.... (or you cede the handful of missions where carriers think they fly 200pax to 4500nm profitably to the A321XLR)

Universally, once you start going over 4000nm you are on a different continent from where you started (the Halifax to Mexico City was an extreme example where you actually stay on the same continent).

You make NMA/NSA too capable and you leave MAX to server the market and continuing to loose to A321 at 200-240pax < 2500nm....

anyway, just thoughts...

I generally agree with you, thats why my data point is 5000NM still air. Not 5000NM+ in real world.

Taxi645 wrote:

morrisond wrote:

Taxi645 wrote:

Again, some are too focused on capacity vs. market. If a smaller plane with the same range can serve the same market because it can offset it's smaller size with way lower costs (variable as well as acquisition cost) the market will be well served. If you have a 3x3 that can do 5.200 Nm, it does not have to seat widebody capacity, because it will be so cheap it doesn't matter for the vast majority of missions.

You are not going to use a 150 seat aircraft on JFK-MIA in 2040 - where will you get the slots?

"because it will be so cheap it doesn't matter for the vast majority of missions."

Who is talking about 150 seats? A ~50m 3x3 would be sufficient.

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

Taxi645 wrote:

morrisond wrote:

Taxi645 wrote:

Actually, thinking a bit more on it, a new container could be a key to success for a new Boeing 3x3 cross section. If Boeing would be able to enforce a new container, they might be able to do quite the coop. Their chances of succeeding at such would be an order of magnitude bigger with a single 3x3 cross section compared to having different fuselage cross sections for NMA and NSA. If they were able to launch a lower and wider container than the LD3-43, that would open up a whole avenue of opportunity for them against the A320 (and less important the MC-21 as well). Possibly enough advantage to be able to survive through the ramp up face against a 60+/month A320 rate.

If they would be able to enforce a lower and wider container, combined with a circular MC-21 sized 3x3 cross section, they would be able to lower the floor and thus hugely increase the available headspace. That could mean that, based on the 4.06 m MC-21 diameter (again identical circumference/wetted area as the A320) the width of the cabin at head height could be about 13 cm / 5'' wider than the A320 with practically the same wetted area. That means that you can do 74 cm / 29” aisle with 737/787 seat width (at seat height it would even be about 15 cm / 6’’ wider). On top of that one would make better use of the cargo part of the cross section with less dead space.





If Boeing would be able to pull that off, they might even put the A320 in trouble. The MC-21 would not be able to do the same because it's floor is already fixed in design to serve LD3-45. They didn't have the cloud to do the same trick Boeing might be able to do. It would have an around 30 cm / 12'' wider and much taller cabin than the 757, providing a completely different medium haul cabin experience.

Neat idea - but I doubt that a wider container would be lower. I'm assuming for an NMA it's about 30" wider (in the largest part) but probably keeping the same height - maybe a few inches higher - but keeping the same height would make it more common with LD3-45.

Funny thing when you do the math on a 2x3x2 with two 17" Aisles (Only 1" less than 777X) vs a 3x3 of the same capacity - due to the 2x3x2 being shorter the aisle area floor penalty is only about 40% - and equivalent to an 27" aisle in a 3x3. That is a no-brainer trade - any airline would take the 2 aisle for a lot better turnover and circulation in the cabin.

What you're missing is this would provide a 74 cm / 29'' aisle and have 100% cross section commonality between NSA and NMA. No one is going to want 2x 17'' aisle if you can have practically the same boarding speed and much more comfort flexibility with a cabin that can offer one 29'' aisle and has 100% cross section commonality with NSA and the same wetted area as an A320.

Personally I would take 2 x17" which is only 1" less than 777X - and the aisles would consume less floor space than your 29" aisle and the aircraft would have have less wetted area by about 2% - I think it's a better trade.

No reason you couldn't use the smaller (volume) cross section for NSA as well.

Teardrops are pretty aero vs pencils.

CRJockey wrote:

morrisond wrote:

However a future NSA with the same cross section but smaller wing/wingbox/tail and engines and equivalent to 322+ plus in size will be flying JFK-MIA and turn times could be very important.

I always thought the US is so frequency driven? No, not even in 2040 will MIA - JFK be flown by 15-20 daily frequencies with 250 seats.

MOM is a transatlantic, transcontinental tool. MOM will be abused, like so many other planes, for shorter trunk routes on some rare occasions. It will not be built for those occasions.

Thats why you build an NSA then with the same cross section.

morrisond wrote:

This is really making me laugh. So I show that you basically get that extra aisle for more than free (in terms of Volume and skin area) and somehow that is a negative?

As most of the production will be automated - more complex parts won't really add that much more cost.

Nice, laughing is good for your soul.

Apart from that, getting things "for free" sounds to good to be true. That implies, it isn't actually free on an aircraft level. Or it most probably would have been implemented quite a while ago.

And your prediction, that more complex parts won't add that much more cost (what is not much more?) due to automation (what automation?) is quite vague. No offense, really not. It just stands a bit as a lone statement.

morrisond wrote:

CRJockey wrote:

morrisond wrote:

However a future NSA with the same cross section but smaller wing/wingbox/tail and engines and equivalent to 322+ plus in size will be flying JFK-MIA and turn times could be very important.

I always thought the US is so frequency driven? No, not even in 2040 will MIA - JFK be flown by 15-20 daily frequencies with 250 seats.

MOM is a transatlantic, transcontinental tool. MOM will be abused, like so many other planes, for shorter trunk routes on some rare occasions. It will not be built for those occasions.

Thats why you build an NSA then with the same cross section.

Yeah, the stubby one.

If weight is a big issue stopping twin aisle, how is weight justified to use a 4K range aircraft on 1K routes? Why not use a lighter aircraft tailored to 2K range? Even though weight is a big deal, it's only one factor, hence why I think Boeing will go twin aisle on a 200 seater, and 2-2-2 is not out of the question.

DenverTed wrote:

If weight is a big issue stopping twin aisle, how is weight justified to use a 4K range aircraft on 1K routes? Why not use a lighter aircraft tailored to 2K range? Even though weight is a big deal, it's only one factor, hence why I think Boeing will go twin aisle on a 200 seater, and 2-2-2 is not out of the question.

Because the weight-cost penalty is calculated against the inefficiencies in operating several more optimized types. Not many airlines in the world are large enough to justify two types between 50 aircraft, but rather actively accept the inefficiency of the heavier plane. Large enough airlines tend to be far more optimized regarding best aircraft for best use.

I did not read all pages, but to me doing a clean sheet design with a kerosene-burning plane seems a very conservative design. I believe this is rather disappointing. Granted, the hydrogen infrastructure isn't there yet. But the design should then at least be designed to be easily derivable to hydrogern.

TheSonntag wrote:

I did not read all pages, but to me doing a clean sheet design with a kerosene-burning plane seems a very conservative design. I believe this is rather disappointing. Granted, the hydrogen infrastructure isn't there yet. But the design should then at least be designed to be easily derivable to hydrogern.

I think that would largely depend on how synthetic fuel will develop from a cost and sustainability viewpoint. If SAF would become a realistic option, than aircraft wise, not much if anything would have to change.

CRJockey wrote:

morrisond wrote:

This is really making me laugh. So I show that you basically get that extra aisle for more than free (in terms of Volume and skin area) and somehow that is a negative?

As most of the production will be automated - more complex parts won't really add that much more cost.

Nice, laughing is good for your soul.

Apart from that, getting things "for free" sounds to good to be true. That implies, it isn't actually free on an aircraft level. Or it most probably would have been implemented quite a while ago.

And your prediction, that more complex parts won't add that much more cost (what is not much more?) due to automation (what automation?) is quite vague. No offense, really not. It just stands a bit as a lone statement.

I think what we are going to find is shapes like what Ostrower thinks the NMA is (Double Circle) are only possible in CFRP at a reasonable weight.

Free in terms of Geometry - it just so happens that structurally shorter and fatter is more efficient from a volume standpoint than long and thin. A ball is perfect.

More complex parts won't add much more cost due to automation as Human labour costs will be much lower. Just look at what is happening with Fan Blades and turbine parts - costs are plunging as the production becomes more automated - more complex means more design time - but once done - the extra labour component is very small.

If we ever see an 2x3x2 cross section in the flesh I think we will all be pretty surprised at how simple it is.

CRJockey wrote:

morrisond wrote:

CRJockey wrote:

I always thought the US is so frequency driven? No, not even in 2040 will MIA - JFK be flown by 15-20 daily frequencies with 250 seats.

MOM is a transatlantic, transcontinental tool. MOM will be abused, like so many other planes, for shorter trunk routes on some rare occasions. It will not be built for those occasions.

Thats why you build an NSA then with the same cross section.

Yeah, the stubby one.

With appropriately sized wings and tail so it doesn't seem so stubby - a teardrop is more aero than a pencil.

morrisond wrote:

Taxi645 wrote:

morrisond wrote:

Neat idea - but I doubt that a wider container would be lower. I'm assuming for an NMA it's about 30" wider (in the largest part) but probably keeping the same height - maybe a few inches higher - but keeping the same height would make it more common with LD3-45.

Funny thing when you do the math on a 2x3x2 with two 17" Aisles (Only 1" less than 777X) vs a 3x3 of the same capacity - due to the 2x3x2 being shorter the aisle area floor penalty is only about 40% - and equivalent to an 27" aisle in a 3x3. That is a no-brainer trade - any airline would take the 2 aisle for a lot better turnover and circulation in the cabin.

What you're missing is this would provide a 74 cm / 29'' aisle and have 100% cross section commonality between NSA and NMA. No one is going to want 2x 17'' aisle if you can have practically the same boarding speed and much more comfort flexibility with a cabin that can offer one 29'' aisle and has 100% cross section commonality with NSA and the same wetted area as an A320.

Personally I would take 2 x17" which is only 1" less than 777X - and the aisles would consume less floor space than your 29" aisle and the aircraft would have have less wetted area by about 2% - I think it's a better trade.

No reason you couldn't use the smaller (volume) cross section for NSA as well.

Teardrops are pretty aero vs pencils.

Advantage circular MC21 sized 3x3 with lowered floor vs oval

- Flexibility in seat width vs aisle width. (both short haul boarding speed and medium haul seat width comfort possible).
- Very comfortable economy possible vs. only 737 width possible.
- No ultra narrow 17’’ aisles
- No floor in compression
- Much more cargo space
- Shared cross section with NSA (you can forget about a 2x3x2 737-7 sized aircraft)
- Both would need a new container.

Basically it is the same basic concept as the oval, just without going as far as putting the floor in compression while maintaining shared NMA/NSA cross section. Further more keep in mind that the oval shape has even more of a cabin width at head height disadvantage than circular already has in relation to the taller than wide A320. You're not gaining back all the width you gain in actual usable cabin width, because the width head height will be the limiting factor. That's where a new container with less would help out, because you put the passenger in a more advantageous position in relation to the curvature of the side wall.

I post this, but since you posted about 300 posts about how you consider the oval to be superior I don't expect you to objectively consider what I said and I don't have an interest in a repetitive discussion.

morrisond wrote:

Taxi645 wrote:

morrisond wrote:

You are not going to use a 150 seat aircraft on JFK-MIA in 2040 - where will you get the slots?

"because it will be so cheap it doesn't matter for the vast majority of missions."

Who is talking about 150 seats? A ~50m 3x3 would be sufficient.

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

morrisond wrote:

Taxi645 wrote:

morrisond wrote:

You are not going to use a 150 seat aircraft on JFK-MIA in 2040 - where will you get the slots?

"because it will be so cheap it doesn't matter for the vast majority of missions."

Who is talking about 150 seats? A ~50m 3x3 would be sufficient.

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

Nope, as noted in the configuration thread the 232 that you envisage compared directly to an A321 plus one row or approximately 246 pax at max capacity.

viewtopic.php?f=5&t=1457749

The required 285max capacity would put the length of the 2-3-2 at around 47.5m. The increased weight per pax in the fuselage is 7+%. A rounded view as to how this affects overall performance can be found here from analysis last year.

viewtopic.php?t=1440759
All you have to do to make the concept work is hold two distinct concepts in your head at a time and only pick the variables that are best to make the numbers work.


Fred


Sent from my iPad using Tapatalk

Taxi645 wrote:

TheSonntag wrote:

I did not read all pages, but to me doing a clean sheet design with a kerosene-burning plane seems a very conservative design. I believe this is rather disappointing. Granted, the hydrogen infrastructure isn't there yet. But the design should then at least be designed to be easily derivable to hydrogern.

I think that would largely depend on how synthetic fuel will develop from a cost and sustainability viewpoint. If SAF would become a realistic option, than aircraft wise, not much if anything would have to change.

Yes, however the efficiency of synthetic fuel is considerably worse than that of Hydrogen (which already is bad compared to batteries, which however are unsuitable for large aeroplanes).

However, I agree that synthetic fuel is easier to integrate into the existing system. However, even with most modern designs, even a clean-sheet aeroplane, a gas turbine remains rather inefficient. It doesn't get better with synthetic fuels.

TheSonntag wrote:

Taxi645 wrote:

TheSonntag wrote:

I did not read all pages, but to me doing a clean sheet design with a kerosene-burning plane seems a very conservative design. I believe this is rather disappointing. Granted, the hydrogen infrastructure isn't there yet. But the design should then at least be designed to be easily derivable to hydrogern.

I think that would largely depend on how synthetic fuel will develop from a cost and sustainability viewpoint. If SAF would become a realistic option, than aircraft wise, not much if anything would have to change.

Yes, however the efficiency of synthetic fuel is considerably worse than that of Hydrogen (which already is bad compared to batteries, which however are unsuitable for large aeroplanes).

However, I agree that synthetic fuel is easier to integrate into the existing system. However, even with most modern designs, even a clean-sheet aeroplane, a gas turbine remains rather inefficient. It doesn't get better with synthetic fuels.

I will readily admit, that for me the total equation from energy source to energy used per seat mile is much too complex to make any sensible predictions. You'll need a complete team of specialists for each section of the whole chain to make a decent estimate. I don't really care if that is hydrogen or SAF and with what design. Yes something completely different is exiting, but in the end, to an airline it is a tool to do the job.

TheSonntag wrote:

Taxi645 wrote:

TheSonntag wrote:

I did not read all pages, but to me doing a clean sheet design with a kerosene-burning plane seems a very conservative design. I believe this is rather disappointing. Granted, the hydrogen infrastructure isn't there yet. But the design should then at least be designed to be easily derivable to hydrogern.

I think that would largely depend on how synthetic fuel will develop from a cost and sustainability viewpoint. If SAF would become a realistic option, than aircraft wise, not much if anything would have to change.

Yes, however the efficiency of synthetic fuel is considerably worse than that of Hydrogen (which already is bad compared to batteries, which however are unsuitable for large aeroplanes).

However, I agree that synthetic fuel is easier to integrate into the existing system. However, even with most modern designs, even a clean-sheet aeroplane, a gas turbine remains rather inefficient. It doesn't get better with synthetic fuels.

Just looking at the cycle efficiency for a "fuel" source is irrelevant to what is best for large aircraft. From production (just assuming renewable source for the example) to propulsion output, battery-electric will have the highest cycle efficiency (production, storage, transmission, charging, discharging, motor use), followed by H2 fuel cell followed by synthetic hydrocarbon fuel. However, for large aircraft, batteries are far too heavy and expensive. There is a direct (well probably increases at a higher rate than that but I'll keep it simple) relationship between increased range and increased weight and cost. Weight, which doesn't decrease throughout the flight.

For H2 fuel cell, you need enormous tanks that are insulated and pressurized. At some point, the additional weight and drag offset the lower efficiency of a synthetic hydrocarbon fuel. H2 would also require massive new infrastructure for storage and fueling.

The other advantage of synthetic fuel is that the benefits can be taken advantage of by existing aircraft, not just new designs.

It's different than ground based travel. For light vehicles (passenger cars, light trucks), battery electric seems to make the most sense. For large vehicles where range and refueling time is much more important (long haul trucking, etc.), I'd imagine hydrogen fuel cell would win out. Synthetic hydrocarbon would probably come in a very distant third for ground based transportation but it might come in a distant first for large aircraft.

Taxi645 wrote:

morrisond wrote:

Taxi645 wrote:

What you're missing is this would provide a 74 cm / 29'' aisle and have 100% cross section commonality between NSA and NMA. No one is going to want 2x 17'' aisle if you can have practically the same boarding speed and much more comfort flexibility with a cabin that can offer one 29'' aisle and has 100% cross section commonality with NSA and the same wetted area as an A320.

Personally I would take 2 x17" which is only 1" less than 777X - and the aisles would consume less floor space than your 29" aisle and the aircraft would have have less wetted area by about 2% - I think it's a better trade.

No reason you couldn't use the smaller (volume) cross section for NSA as well.

Teardrops are pretty aero vs pencils.

Advantage circular MC21 sized 3x3 with lowered floor vs oval

- Flexibility in seat width vs aisle width. (both short haul boarding speed and medium haul seat width comfort possible).
- Very comfortable economy possible vs. only 737 width possible.
- No ultra narrow 17’’ aisles
- No floor in compression
- Much more cargo space
- Shared cross section with NSA (you can forget about a 2x3x2 737-7 sized aircraft)
- Both would need a new container.

Basically it is the same basic concept as the oval, just without going as far as putting the floor in compression while maintaining shared NMA/NSA cross section. Further more keep in mind that the oval shape has even more of a cabin width at head height disadvantage than circular already has in relation to the taller than wide A320. You're not gaining back all the width you gain in actual usable cabin width, because the width head height will be the limiting factor. That's where a new container with less would help out, because you put the passenger in a more advantageous position in relation to the curvature of the side wall.

I post this, but since you posted about 300 posts about how you consider the oval to be superior I don't expect you to objectively consider what I said and I don't have an interest in a repetitive discussion.

But it's not an Oval. If Boeing was going to do a 3x3 they would be crazy to do anything larger than A320.

So an 18" aisle works for 777x - but one inch less for an aircraft that will be in the air less than half the stage length of 777x doesn't? Ok then make them 18" and they use the same floor space as a 29" aisle.

The 737-7 size is dead anyways by - 2035 738 might be as well.

Ok - you might have something on the lower container.

morrisond wrote:

CRJockey wrote:

morrisond wrote:

Thats why you build an NSA then with the same cross section.

Yeah, the stubby one.

With appropriately sized wings and tail so it doesn't seem so stubby - a teardrop is more aero than a pencil.

You sure?

You might be right but then what do you mean by ‘aero’?
Drag? Lift to drag? Drag per volume? Drag per unit of surface area? Drag per unit of longitudinal cross sectional area? Drag coefficient in the incompressible regime? Drag coefficient across the transonic region? There are an almost infinit number of things that could be inferred from ‘aero’

Fred


Sent from my iPad using Tapatalk

flipdewaf wrote:

morrisond wrote:

Taxi645 wrote:

Who is talking about 150 seats? A ~50m 3x3 would be sufficient.

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

morrisond wrote:

Taxi645 wrote:

Who is talking about 150 seats? A ~50m 3x3 would be sufficient.

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

Nope, as noted in the configuration thread the 232 that you envisage compared directly to an A321 plus one row or approximately 246 pax at max capacity.

viewtopic.php?f=5&t=1457749

The required 285max capacity would put the length of the 2-3-2 at around 47.5m. The increased weight per pax in the fuselage is 7+%. A rounded view as to how this affects overall performance can be found here from analysis last year.

viewtopic.php?t=1440759
All you have to do to make the concept work is hold two distinct concepts in your head at a time and only pick the variables that are best to make the numbers work.


Fred


Sent from my iPad using Tapatalk

I was comparing 3x3 and 2x3x2 at same capacity.

Or to make the concept work - you have to make sure some basic assumptions like appropriate end lengths are used.

morrisond wrote:

flipdewaf wrote:

morrisond wrote:

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

morrisond wrote:

Sorry - I thought you meant smaller in terms of Capacity.

BTW an equivalent 2x3x2 to that 50M 3x3 would be around 44M and have about 9% less skin area and 2-3% Less internal volume - does that make it larger?

Nope, as noted in the configuration thread the 232 that you envisage compared directly to an A321 plus one row or approximately 246 pax at max capacity.

viewtopic.php?f=5&t=1457749

The required 285max capacity would put the length of the 2-3-2 at around 47.5m. The increased weight per pax in the fuselage is 7+%. A rounded view as to how this affects overall performance can be found here from analysis last year.

viewtopic.php?t=1440759
All you have to do to make the concept work is hold two distinct concepts in your head at a time and only pick the variables that are best to make the numbers work.


Fred


Sent from my iPad using Tapatalk

I was comparing 3x3 and 2x3x2 at same capacity.

I did use the same capacity, did you also use the same seat width?

morrisond wrote:

Or to make the concept work - you have to make sure some basic assumptions like appropriate end lengths are used.

Yes, I would absolutely agree. I would use a standard constant to avoid confusion, much barter than muddying waters by special pleading.

Fred


Sent from my iPad using Tapatalk

So it would seem all of this boils down to two things: (1) Boeing needs a clean-sheet 737 replacement (2) The market wants/needs a 757/767 replacement

As much as Boeing would love for it to be the case, methinks you cannot achieve both with a single aircraft type. A super long single-aisle isn't going to cut it, nor will a stubby double-aisle. This will have to be two different airplanes.

Cdydatzigs wrote:

So it would seem all of this boils down to two things: (1) Boeing needs a clean-sheet 737 replacement (2) The market wants/needs a 757/767 replacement

As much as Boeing would love for it to be the case, methinks you cannot achieve both with a single aircraft type. A super long single-aisle isn't going to cut it, nor will a stubby double-aisle. This will have to be two different airplanes.

As said, that depends if you only look at capacities or of you rather look at markets to serve in stead.

morrisond wrote:

Taxi645 wrote:

morrisond wrote:

Personally I would take 2 x17" which is only 1" less than 777X - and the aisles would consume less floor space than your 29" aisle and the aircraft would have have less wetted area by about 2% - I think it's a better trade.

No reason you couldn't use the smaller (volume) cross section for NSA as well.

Teardrops are pretty aero vs pencils.

Advantage circular MC21 sized 3x3 with lowered floor vs oval

- Flexibility in seat width vs aisle width. (both short haul boarding speed and medium haul seat width comfort possible).
- Very comfortable economy possible vs. only 737 width possible.
- No ultra narrow 17’’ aisles
- No floor in compression
- Much more cargo space
- Shared cross section with NSA (you can forget about a 2x3x2 737-7 sized aircraft)
- Both would need a new container.

Basically it is the same basic concept as the oval, just without going as far as putting the floor in compression while maintaining shared NMA/NSA cross section. Further more keep in mind that the oval shape has even more of a cabin width at head height disadvantage than circular already has in relation to the taller than wide A320. You're not gaining back all the width you gain in actual usable cabin width, because the width head height will be the limiting factor. That's where a new container with less would help out, because you put the passenger in a more advantageous position in relation to the curvature of the side wall.

I post this, but since you posted about 300 posts about how you consider the oval to be superior I don't expect you to objectively consider what I said and I don't have an interest in a repetitive discussion.

But it's not an Oval. If Boeing was going to do a 3x3 they would be crazy to do anything larger than A320.

As said, a zillion times already it is not larger than an A320, just wider.

So an 18" aisle works for 777x - but one inch less for an aircraft that will be in the air less than half the stage length of 777x doesn't? Ok then make them 18" and they use the same floor space as a 29" aisle.

I didn't say it wouldn't work, I said it is a drawback.

The 737-7 size is dead anyways by - 2035 738 might be as well.

The reason the 737-7 and A319 are dead is not because of their geometry, but because the new found SFC improvement have made them uncompetitive based on their legacy MTOW designs. That would be different with a clean sheet which would reinstate a meaningful range advantage for the smallest model. See the table listed above.

Does 2-2-2 ever make any sense if you are going twin aisle? 2-3-2 at least gets you one more seat per row so the same capacity can be 16% shorter. I would assume the extra weight and wetted area from the one additional seat would easily be offset by the reduced length.

I guess the only way I could see it making any sense to do 2-2-2 would be if the design was 3-3 with 18" seats and 28" aisle and there was an optional 2-2-2 configuration with 17" seats and two 17" aisles. Basically trade seat width comfort for no middle seat and somewhat faster boarding and deplaning. Also, I'd think a 2-2-2 would cause the overhead bins to be an issue since they'd have to not protrude past 34" when open.

morrisond wrote:

More complex parts won't add much more cost due to automation as Human labour costs will be much lower. Just look at what is happening with Fan Blades and turbine parts

I can give you two data points directly to your example, that point to the contrary.

In 2011, a fanblade for the CF6-80C2 made from good old titanium did cost about 30.000 USD new.

A complete overhaul of the highest thrust variant -D1F was about three million USD, plus or minus half a million depending on scope of work.

In 2012, a fanblade for the GE90-110, manufactured in layered CFRP with metal leading edge, arguably the much more complex part, cost more than 100k USD per piece.

Overhaul workscopes for the large diameter GE90s can easily be 10 Mio USD. Arguably, the GE90 is a much more complex engine in order to extract the higher efficiency.

No, neither fan blades and especially not turbine blades or vanes are getting cheaper by any stretch of the imagination.

planecane wrote:

Does 2-2-2 ever make any sense if you are going twin aisle? 2-3-2 at least gets you one more seat per row so the same capacity can be 16% shorter. I would assume the extra weight and wetted area from the one additional seat would easily be offset by the reduced length.

I guess the only way I could see it making any sense to do 2-2-2 would be if the design was 3-3 with 18" seats and 28" aisle and there was an optional 2-2-2 configuration with 17" seats and two 17" aisles. Basically trade seat width comfort for no middle seat and somewhat faster boarding and deplaning. Also, I'd think a 2-2-2 would cause the overhead bins to be an issue since they'd have to not protrude past 34" when open.

The McDonnell-Douglas ATMR concept was originally designed as a 2+2+2 frame with 18" seats and wide aisles, but had the fuselage expanded so it could support 2+3+2 with 16.5" seats and narrow aisles intended for charter operators. The frame did not have center bins.

morrisond wrote:

The 737-7 size is dead anyways by - 2035

It certainly will be at 6-abreast.
History seems pretty clear that shorter and fatter ultimately fails against longer and narrower at the capacity crossover

Rgds

planecane wrote:

Does 2-2-2 ever make any sense if you are going twin aisle? 2-3-2 at least gets you one more seat per row so the same capacity can be 16% shorter. I would assume the extra weight and wetted area from the one additional seat would easily be offset by the reduced length.

I guess the only way I could see it making any sense to do 2-2-2 would be if the design was 3-3 with 18" seats and 28" aisle and there was an optional 2-2-2 configuration with 17" seats and two 17" aisles. Basically trade seat width comfort for no middle seat and somewhat faster boarding and deplaning. Also, I'd think a 2-2-2 would cause the overhead bins to be an issue since they'd have to not protrude past 34" when open.

I think the advantage of 2-2-2 over 2-3-2 is that it is better at the smallest size. That size being, if WN went for a 200 seat twin aisle at 32" pitch, would 2-2-2 better solution or a wider and shorter 2-3-2. For 200 seat multi-class, or 240 at 30" pitch, I could see 2-2-2 being a better proportioned aircraft leading to gains in efficiency. If there is an ideal proportion of width to length, based on the structure and size of the tail, then 2-2-2 would have some benefits.

morrisond wrote:

FluidFlow wrote:

morrisond wrote:

But a tight light 2 class 2x3x2 does not have more volume than a 3x3 when you adjust for similar capacity. The 2x3x2 actually has about 9% less skin and 2% less internal volume - that extra seat being basically in the bulge is a very efficient cost in volume - basically the decrease in length of the cabin more than offsets the increased width of a tight 2x3x2.. The penalty in aisle space is only about 1.4x for two 17" aisles vs one 19" aisle.

Boeing is calling it a 2 Class aircraft (according the AVWeek article). I think Boeing is seeing the writing on the wall and they know by the time this aircraft arrives COMAC could be a major player. They will have a very hard time competing with them for airlines that are all Y or Y-. An all Y NMA has about 1% less Skin and 6.5% more internal volume. They need to differentiate themselves as Calhoun has stated.

A 168x183" cross section gets you containers than can carry about 50% more than an LD3-45 offset by the reduced cabin length - so probably about 20-25% more cargo capacity than the 3x3.

So you compromise the optimal shape (now a sphere is the perfect shape, but for an aircraft it is more or less a circle) to not gain any volume just to have an aisle? Why would you do that if you no not want more seats? So if you aim at the same capacity then you do not need any special shape. The point is, that if you compare a 240 seats circle with a 240 seats ovoid (or whatever weird shape you go for), you only add complexity without any additional capacity. This does not help the case. To make it worth while you need to increase capacity what also needs more MTOW, what makes the design heavier.

And for the containers:
If it does not take LD3-45s it is dead in the water. There are billions invested in automated cargo systems that take LD3-45 (or the wide body version of the LD3 and LD2 containers). So no one will accept different shapes and sizes just because Boeing builds a strange shaped pax aircraft.
That means the shorter cabin would lead to actually less cargo capacity because you can carry less containers.
The only other option would than be to bulk load to use the wider cargo bay but that would make turn around times horrible because bulk loading long haul operations where we have more checked luggage would be a nightmare (operational).

This is really making me laugh. So I show that you basically get that extra aisle for more than free (in terms of Volume and skin area) and somehow that is a negative?

As most of the production will be automated - more complex parts won't really add that much more cost.

The point of this cross section - as others have pointed out above is that it could be the cross section for NSA as well and range up to 300 seats. It also differentiates Boeing as the premium product against COMAC which will be a much larger threat by EIS and Airbus if they do not go clean sheet (and they could easily do something like this 2x3x2 and would have more room to do so given they have the A220 - then they have 5W, 7W and 9W assuming A330 death - which is perfect).

For the container size the market will adapt - as others have pointed out many of there existing 737 Customers do not have the cargo handling equipment yet anyways - if the Cross section is also used for NSA then you are talking about an installed base of easily over 10,000 frames in the 2030's and 2040's. Some more Cargo Handling equipment won't be an issue. No reason you won't be able to put an LD3-45 in it either. - Less Capacity - but packed full for LR missions you might be Cargo limited anyways. Short Haul you don't need that much space in the belly.

In any case a new Container is not a show stopper.

Free volume does nothing for an aircraft. A ballon and a bowling ball also have the same volume but one flies when you fill it with helium.

No and Boeing can not force a wider container just like that, especially because every aircraft designed after 1980 uses LD3(-45s). They are all transferable from one to another and even into feeder aircraft. We will be stuck with them, they even load LD3s into the 747s even though they woule have LD1s .The LD2 is somewhat an oddball here.
A new container would drive costs into oblivion because if you want to buy the new aircraft you would also have to buy new cargo equipment. Thats not what a lean aircraft does.

Also using a stunby aircraft for the 240pax market means everything below is conceeded to the competitors.
And also the shorter the aircraft the bigger the tail what means that all the bigger versions need a new tail so you have two tails or a bad compromise at one end of the spectrum. This all adds cost.

So we really should just listen to Calhoun: Boeing targets the A321 family. So 180-200 two class with up to 4500nm range. If Boeing can do that with 85t MTOW it will be an aircraft selling 10‘000 copies.

If Boeing builds a 240 two class 150t aircraft they might sell 1500 tops and take 500 away from the 787.

Now where would the big shareholders (that control the board) put their money?

FiscAutTecGarte wrote:

Why does the NMA/NSA need to approach such long distances? With all that capability it will be rather comprimised for uhhhhh, middle of the market missions, no?

Do we really need to fly this far with just 250 people? Is this really the Market? Even a A321XLR is not going to fly any more than 200pax to 4500nm.. or 240pax to 4000nm... under the best of conditions.

United and American have both invested heavily in the A321XLR with 50 each and have said they plan to use part of those fleets to expand into new TATL routes. So Boeing might be planning NMA-6X and NMA-7X to serve as natural upgrades for A321XLR routes that grow beyond the capacity of the A321XLR. In other words, A321XLRs would launch these routes and if they prove popular, NMAs would move in to handle the increased traffic.

Delta, whom one would expect to be a major A321XLR customer, has yet to order any because they are said to be waiting for NMA. Could it be that Delta feels that the A321XLR is too small for TATL or that NMA's cost-per-seat would be sufficiently lower to make it a better option (lower fares able to fill those extra seats)?

TheSonntag wrote:

I did not read all pages, but to me doing a clean sheet design with a kerosene-burning plane seems a very conservative design. I believe this is rather disappointing. Granted, the hydrogen infrastructure isn't there yet. But the design should then at least be designed to be easily derivable to hydrogern.

Hydrogen and kerosene are far too different to make an aircraft easily derived to switch between fuels. It's not even a matter of swapping engines and fuel lines.

Although hydrogen has very good energy density on a mass basis, it has poor energy density on a volume basis. A liquid hydrogen fueled airliner would need 3 times the fuel tank volume in order to maintain the same range as a kerosene fueled model. The tanks need to be insulated to reduce boil-off and prevent temperature related problems like condensation or cold embrittlement of nearby structural materials or wire insulation.

Wing fuel tanks could be challenging to make work. If you look at Airbus's hydrogen ZEROe concepts, they move the fuselage rear pressure bulkhead forward to provide for a large fuel tank in the aft fuselage.

https://www.airbus.com/newsroom/press-r ... craft.html

TheSonntag wrote:

Yes, however the efficiency of synthetic fuel is considerably worse than that of Hydrogen (which already is bad compared to batteries, which however are unsuitable for large aeroplanes).

However, I agree that synthetic fuel is easier to integrate into the existing system. However, even with most modern designs, even a clean-sheet aeroplane, a gas turbine remains rather inefficient. It doesn't get better with synthetic fuels.

If both fuels are being burned in a gas turbine, the efficiency in use will be similar. We could get better efficiency from hydrogen with fuel cells, but those do not provide the power to weight needed for aviation.

Efficiency and cost effectiveness of producing the fuel is a more complex topic. I won't get into that right now, other than to note that the cheapest biofuel production methods are not the most efficient nor the methods with the most significant greenhouse gas reduction.

flipdewaf wrote:

morrisond wrote:

flipdewaf wrote:

Nope, as noted in the configuration thread the 232 that you envisage compared directly to an A321 plus one row or approximately 246 pax at max capacity.

viewtopic.php?f=5&t=1457749

The required 285max capacity would put the length of the 2-3-2 at around 47.5m. The increased weight per pax in the fuselage is 7+%. A rounded view as to how this affects overall performance can be found here from analysis last year.

viewtopic.php?t=1440759
All you have to do to make the concept work is hold two distinct concepts in your head at a time and only pick the variables that are best to make the numbers work.


Fred


Sent from my iPad using Tapatalk

I was comparing 3x3 and 2x3x2 at same capacity.

I did use the same capacity, did you also use the same seat width?

morrisond wrote:

Or to make the concept work - you have to make sure some basic assumptions like appropriate end lengths are used.

Yes, I would absolutely agree. I would use a standard constant to avoid confusion, much barter than muddying waters by special pleading.

Fred


Sent from my iPad using Tapatalk

Well when you are determined to use a constant that might not apply in this case and someone says maybe you might want to think of it another way - I would not call it pleading - I would call it trying to be civil to each other vs your constant put downs when you don't like something somebody points out vs looking at it scientifically and seeing if you might have missed something.

No biggie if you did. I'm really just trying to help ad dispel the notion that many have that the NMA is a lot bigger than what Boeing seems to be aiming for now - and was in the past before the larger NMA's appeared in the last few years. The NMA -5X really seems to be A322 size, with wings and tail appropriately sized.

CRJockey wrote:

morrisond wrote:

More complex parts won't add much more cost due to automation as Human labour costs will be much lower. Just look at what is happening with Fan Blades and turbine parts

I can give you two data points directly to your example, that point to the contrary.

In 2011, a fanblade for the CF6-80C2 made from good old titanium did cost about 30.000 USD new.

A complete overhaul of the highest thrust variant -D1F was about three million USD, plus or minus half a million depending on scope of work.

In 2012, a fanblade for the GE90-110, manufactured in layered CFRP with metal leading edge, arguably the much more complex part, cost more than 100k USD per piece.

Overhaul workscopes for the large diameter GE90s can easily be 10 Mio USD. Arguably, the GE90 is a much more complex engine in order to extract the higher efficiency.

No, neither fan blades and especially not turbine blades or vanes are getting cheaper by any stretch of the imagination.

You are comparing two engines with one that is almost double in thrust. Plus the GE90 is unique in that it has no competitors so it can enjoy Premium pricing.

There are many posts on this site talking about how new tech has radically reduced the cost of producing turbine parts vs 100's of hours of machining done previously.

Apparently the Ge-9X has employed quite a bit of this tech - that is the much better comparison to the Ge90-110/115.

FluidFlow wrote:

morrisond wrote:

FluidFlow wrote:

So you compromise the optimal shape (now a sphere is the perfect shape, but for an aircraft it is more or less a circle) to not gain any volume just to have an aisle? Why would you do that if you no not want more seats? So if you aim at the same capacity then you do not need any special shape. The point is, that if you compare a 240 seats circle with a 240 seats ovoid (or whatever weird shape you go for), you only add complexity without any additional capacity. This does not help the case. To make it worth while you need to increase capacity what also needs more MTOW, what makes the design heavier.

And for the containers:
If it does not take LD3-45s it is dead in the water. There are billions invested in automated cargo systems that take LD3-45 (or the wide body version of the LD3 and LD2 containers). So no one will accept different shapes and sizes just because Boeing builds a strange shaped pax aircraft.
That means the shorter cabin would lead to actually less cargo capacity because you can carry less containers.
The only other option would than be to bulk load to use the wider cargo bay but that would make turn around times horrible because bulk loading long haul operations where we have more checked luggage would be a nightmare (operational).

This is really making me laugh. So I show that you basically get that extra aisle for more than free (in terms of Volume and skin area) and somehow that is a negative?

As most of the production will be automated - more complex parts won't really add that much more cost.

The point of this cross section - as others have pointed out above is that it could be the cross section for NSA as well and range up to 300 seats. It also differentiates Boeing as the premium product against COMAC which will be a much larger threat by EIS and Airbus if they do not go clean sheet (and they could easily do something like this 2x3x2 and would have more room to do so given they have the A220 - then they have 5W, 7W and 9W assuming A330 death - which is perfect).

For the container size the market will adapt - as others have pointed out many of there existing 737 Customers do not have the cargo handling equipment yet anyways - if the Cross section is also used for NSA then you are talking about an installed base of easily over 10,000 frames in the 2030's and 2040's. Some more Cargo Handling equipment won't be an issue. No reason you won't be able to put an LD3-45 in it either. - Less Capacity - but packed full for LR missions you might be Cargo limited anyways. Short Haul you don't need that much space in the belly.

In any case a new Container is not a show stopper.

Free volume does nothing for an aircraft. A ballon and a bowling ball also have the same volume but one flies when you fill it with helium.

No and Boeing can not force a wider container just like that, especially because every aircraft designed after 1980 uses LD3(-45s). They are all transferable from one to another and even into feeder aircraft. We will be stuck with them, they even load LD3s into the 747s even though they woule have LD1s .The LD2 is somewhat an oddball here.
A new container would drive costs into oblivion because if you want to buy the new aircraft you would also have to buy new cargo equipment. Thats not what a lean aircraft does.

Also using a stunby aircraft for the 240pax market means everything below is conceeded to the competitors.
And also the shorter the aircraft the bigger the tail what means that all the bigger versions need a new tail so you have two tails or a bad compromise at one end of the spectrum. This all adds cost.

So we really should just listen to Calhoun: Boeing targets the A321 family. So 180-200 two class with up to 4500nm range. If Boeing can do that with 85t MTOW it will be an aircraft selling 10‘000 copies.

If Boeing builds a 240 two class 150t aircraft they might sell 1500 tops and take 500 away from the 787.

Now where would the big shareholders (that control the board) put their money?

On an 200-220 Seat (A322 plus a little bit - realistic seat pitch) 2 Class NMA that weighs maybe 110-120T and will take that load out to a real 4-500- 5,000, whereas an A322 without a new wing would carry that load maybe 3,300NM.

If Boeing could actually build an 85T aircraft that does 4,500 with 200 two class - Airbus would have no hope in hell at competing - you are probably talking more about 105-110T even for a 3x3 to have that capability.

The 85T 2x3x2 NSA that can only do 3,000 NM will come later. Nothing would stop you from LD3-45 in an NMA - but you would have to think that Boeing has already thought through that problem.

Please show any current article where Boeing is rumoured or contemplating 3x3 for NMA. They want to build a premium product to differentiate themselves. The C919 is coming.