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Checklist787
Posts: 566
Joined: Sat Jun 01, 2019 2:37 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 9:49 am

DenverTed wrote:
morrisond wrote:
DenverTed wrote:
As far as the wing and engine combo, the NMA was about a 45K engine on a 45m wing. I imagine the FSA will downshift to a 35K engine on a 36m wing. Will they build a new CFRP wing with split winglets, or go with 2.5m folding wingtips for a 41m span?
In terms of MTOW, will it be 100t on a single axle like the A321, or move towards 125t with double axle like the 757?


I think if they build NMA/NSA on the same 7W cross section they would look like the following:

NSA -S 36M wing small wing - Engines up to about 32K - MTOW less than 737-9 - as less range and more fuel efficient doesn't have(can't because of the small wing) to carry as much fuel - call it 85T MTOW - Range 3,300ish (don't make it to much to start to maximize efficiency and have room to grow.
NSA-L Same as above - maybe a small thrust bump and 87-88T MTOW

NMA-S 42-43M Wing - whatever they can fold to 36M to fit in same gates as NSA - Engines in the 45K range - Range about 5,300NM 105-110T MTOW
NMA-L same as NMA-S - Engines maybe 47-48K - Range about 4,800NM 110-115T MTOW

Lean and Mean

I'm down with that program. One fuselage, two sets of wings, two models on each wing.


I like two different wings!
What are the disadvantages according to you ?
"No limit to my poooWer!!!
Do it! "...
 
flipdewaf
Posts: 3710
Joined: Thu Jul 20, 2006 6:28 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 9:54 am

Checklist787 wrote:
flipdewaf wrote:
it will, is being right about it being twin aisle what you are worried about?


Absolutely, I'm RIGHT!
Re-read the tweet :wave:

Nah, it’s ok. When you present additional evidence rather than peddling the same BS I’m willing to listen but until then I’ll consider it a continuing tantrum on your part.

@fluidlow for some reason it won’t let me do quoting on my phone. You have it fairly well down in terms of principles. In terms of of weight, a narrower fuselage is always lighter for carrying the pressure loads and a higher fuselage is lighter carrying the bending loads. The further from circular the cross section is the worse it is from a pressure carrying perspective.

The crossover point in terms of where longer makes you heavier then going wider is dependent on specific design decisions such as material selections, payloads, speeds etc etc.

You’ll notice that wide oval has almost the worst of all worlds with regards to carrying loads. The only caveat is really that there could be another determining factor in that there could be a minimum thickness for the skin does to practical construction issues or impact requirements and this may be the limit factor meaning an abs cure shape does not materially affect weight in the traditional way. Whether this means shorter and wider becomes more feasible or that longer and skinnier does I cannot grok at this time, I am trying to build some sort of indicative model for this but I am having to dig out my old university notes and my wife is a bit mardy about it.

Fred


Sent from my iPhone using Tapatalk
Image
 
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keesje
Posts: 14101
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 9:58 am

Checklist787 wrote:
DenverTed wrote:
morrisond wrote:

I think if they build NMA/NSA on the same 7W cross section they would look like the following:

NSA -S 36M wing small wing - Engines up to about 32K - MTOW less than 737-9 - as less range and more fuel efficient doesn't have(can't because of the small wing) to carry as much fuel - call it 85T MTOW - Range 3,300ish (don't make it to much to start to maximize efficiency and have room to grow.
NSA-L Same as above - maybe a small thrust bump and 87-88T MTOW

NMA-S 42-43M Wing - whatever they can fold to 36M to fit in same gates as NSA - Engines in the 45K range - Range about 5,300NM 105-110T MTOW
NMA-L same as NMA-S - Engines maybe 47-48K - Range about 4,800NM 110-115T MTOW

Lean and Mean

I'm down with that program. One fuselage, two sets of wings, two models on each wing.


I like two different wings!
What are the disadvantages according to you ?


The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image
"Never mistake motion for action." Ernest Hemingway
 
FluidFlow
Posts: 737
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 10:14 am

flipdewaf wrote:

@fluidlow for some reason it won’t let me do quoting on my phone. You have it fairly well down in terms of principles. In terms of of weight, a narrower fuselage is always lighter for carrying the pressure loads and a higher fuselage is lighter carrying the bending loads. The further from circular the cross section is the worse it is from a pressure carrying perspective.

The crossover point in terms of where longer makes you heavier then going wider is dependent on specific design decisions such as material selections, payloads, speeds etc etc.

You’ll notice that wide oval has almost the worst of all worlds with regards to carrying loads. The only caveat is really that there could be another determining factor in that there could be a minimum thickness for the skin does to practical construction issues or impact requirements and this may be the limit factor meaning an abs cure shape does not materially affect weight in the traditional way. Whether this means shorter and wider becomes more feasible or that longer and skinnier does I cannot grok at this time, I am trying to build some sort of indicative model for this but I am having to dig out my old university notes and my wife is a bit mardy about it.

Fred


Sent from my iPhone using Tapatalk


What are your thoughts on windows and doors (cabin and cargo). As the hoop stress will be largest in the area where windows and the lower part of the cabin door or the upper part of the cargo door is, all them structures have to be reinforced compared to a traditional tube as you have increased hoop stress on top of local stress fields caused by the doors and windows.
 
flipdewaf
Posts: 3710
Joined: Thu Jul 20, 2006 6:28 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 10:56 am

FluidFlow wrote:
flipdewaf wrote:

@fluidlow for some reason it won’t let me do quoting on my phone. You have it fairly well down in terms of principles. In terms of of weight, a narrower fuselage is always lighter for carrying the pressure loads and a higher fuselage is lighter carrying the bending loads. The further from circular the cross section is the worse it is from a pressure carrying perspective.

The crossover point in terms of where longer makes you heavier then going wider is dependent on specific design decisions such as material selections, payloads, speeds etc etc.

You’ll notice that wide oval has almost the worst of all worlds with regards to carrying loads. The only caveat is really that there could be another determining factor in that there could be a minimum thickness for the skin does to practical construction issues or impact requirements and this may be the limit factor meaning an abs cure shape does not materially affect weight in the traditional way. Whether this means shorter and wider becomes more feasible or that longer and skinnier does I cannot grok at this time, I am trying to build some sort of indicative model for this but I am having to dig out my old university notes and my wife is a bit mardy about it.

Fred


Sent from my iPhone using Tapatalk


What are your thoughts on windows and doors (cabin and cargo). As the hoop stress will be largest in the area where windows and the lower part of the cabin door or the upper part of the cargo door is, all them structures have to be reinforced compared to a traditional tube as you have increased hoop stress on top of local stress fields caused by the doors and windows.

Smaller and less of them and rounder is better for weight purposes but more and bigger and sometime squarer is better for operations, comfort and regulations. I’m not sure on how these would realistically change their effect on a different shaped fuselage, it isn’t something I could figure out as an excel/JMP warrior.

Fred


Sent from my iPhone using Tapatalk
Image
 
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PacoMartin
Posts: 901
Joined: Sun May 27, 2018 8:18 pm

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 11:08 am

ikolkyo wrote:
Behind the scenes, Boeing has been recently briefing a small handful of U.S., European and leasing customers on an all-new aircraft — dubbed the Future Small Airplane (FSA) — whose first models would notionally be 180 to 210-seats. That’s larger than the 737 Max 8, which seats 162 passengers in a two-class configuration.


That sounds like a B752. What a shocker!

B752 nominal 2-class seating 200 (12F+188Y) with 239 max
B752 168-199 seats on delta
 
Checklist787
Posts: 566
Joined: Sat Jun 01, 2019 2:37 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 11:20 am

keesje wrote:
Checklist787 wrote:
DenverTed wrote:
I'm down with that program. One fuselage, two sets of wings, two models on each wing.


I like two different wings!
What are the disadvantages according to you ?


The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image


Interesting !
What is the length and the wingspan?
The cabin width and amenagment seats?
"No limit to my poooWer!!!
Do it! "...
 
FluidFlow
Posts: 737
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 11:29 am

flipdewaf wrote:
FluidFlow wrote:
flipdewaf wrote:

@fluidlow for some reason it won’t let me do quoting on my phone. You have it fairly well down in terms of principles. In terms of of weight, a narrower fuselage is always lighter for carrying the pressure loads and a higher fuselage is lighter carrying the bending loads. The further from circular the cross section is the worse it is from a pressure carrying perspective.

The crossover point in terms of where longer makes you heavier then going wider is dependent on specific design decisions such as material selections, payloads, speeds etc etc.

You’ll notice that wide oval has almost the worst of all worlds with regards to carrying loads. The only caveat is really that there could be another determining factor in that there could be a minimum thickness for the skin does to practical construction issues or impact requirements and this may be the limit factor meaning an abs cure shape does not materially affect weight in the traditional way. Whether this means shorter and wider becomes more feasible or that longer and skinnier does I cannot grok at this time, I am trying to build some sort of indicative model for this but I am having to dig out my old university notes and my wife is a bit mardy about it.

Fred


Sent from my iPhone using Tapatalk


What are your thoughts on windows and doors (cabin and cargo). As the hoop stress will be largest in the area where windows and the lower part of the cabin door or the upper part of the cargo door is, all them structures have to be reinforced compared to a traditional tube as you have increased hoop stress on top of local stress fields caused by the doors and windows.

Smaller and less of them and rounder is better for weight purposes but more and bigger and sometime squarer is better for operations, comfort and regulations. I’m not sure on how these would realistically change their effect on a different shaped fuselage, it isn’t something I could figure out as an excel/JMP warrior.

Fred


Sent from my iPhone using Tapatalk


In a perfect infinite pressurized tube the stresses are equal everywhere but as soon as you cut a piece out (door) the stress will focus along the cut out because this area has to also carry the stresses the cut out cant handle any more. The more square the piece is the more focused the stress is at the corners. So far so good.

In a circular tube that is not a big problem anymore but if the tube is oval we have changing stresses along the cut out due to change in radius of the tube. From the shape this would increase towards the bottom of the passenger doors. There you would have maximum hoops stress from the shape and on top of that the stress from the cut out. This would mean that the structure in the vertex of the oval has to be reinforced meaning a substantial increase in weight while it can not effectively be thinned out at the top or you get there another stress focal point (if the stress is constant, thinner material needs to be stronger to accommodate for it). At the end you need a thinker tube if it is oval compared to a circular tube.

Interesting enough is that a standing oval is better (see 747/A380 and also the other tubes in use to a lesser extent), because the hoop stress focuses at the top and bottom where no other stresses are in play while the increased pressure stress at the side might be negative but the curvature of the features (doors, etc.) is smaller and therefore the stress focus by the cut out seems to be smaller.

So maybe it would be better for the NMA to be two floors with 3-2 on the bottom and 2-1 on the top floor and no cargo space at all. ;-)
 
Checklist787
Posts: 566
Joined: Sat Jun 01, 2019 2:37 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 11:30 am

DenverTed wrote:
morrisond wrote:
DenverTed wrote:
As far as the wing and engine combo, the NMA was about a 45K engine on a 45m wing. I imagine the FSA will downshift to a 35K engine on a 36m wing. Will they build a new CFRP wing with split winglets, or go with 2.5m folding wingtips for a 41m span?
In terms of MTOW, will it be 100t on a single axle like the A321, or move towards 125t with double axle like the 757?


I think if they build NMA/NSA on the same 7W cross section they would look like the following:

NSA -S 36M wing small wing - Engines up to about 32K - MTOW less than 737-9 - as less range and more fuel efficient doesn't have(can't because of the small wing) to carry as much fuel - call it 85T MTOW - Range 3,300ish (don't make it to much to start to maximize efficiency and have room to grow.
NSA-L Same as above - maybe a small thrust bump and 87-88T MTOW

NMA-S 42-43M Wing - whatever they can fold to 36M to fit in same gates as NSA - Engines in the 45K range - Range about 5,300NM 105-110T MTOW
NMA-L same as NMA-S - Engines maybe 47-48K - Range about 4,800NM 110-115T MTOW

Lean and Mean

I'm down with that program. One fuselage, two sets of wings, two models on each wing.


Both concept are good! :checkmark:

Based on the source of J. Ostrower

Here is the FSA-X concept!
The Smaller NMA-Twin Aisles concept :
:thumbsup:
I see,

A 2-2-2 cross section / cabin
5-Abreast Busines/Premium seats 1-3-1
The FSA-8X could be carrying 180 to 250 passengers thanks to possibility config. over a limited narrowbody concept !

Many, 3/4 airlines will fly LCC type missions!

The FSA-X8 concept
L:50 m. Wing Span 44 m.
Carrying 2-class 228 pax /business seat @ 36 in pitch (LCC. config.)
13 LD3-45W's conteners

The FSA-X9 concept
L:57-58 m. Wing Span 44 m.
Carrying 2-class 266 pax /business seat @ 36 in pitch (LCC. config.)
19 LD3-45W's conteners

;)
Regards
"No limit to my poooWer!!!
Do it! "...
 
User avatar
afterburner
Posts: 1459
Joined: Mon Jun 13, 2005 11:38 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 11:58 am

Checklist787 wrote:
afterburner wrote:
Checklist787 wrote:

Hi!

Yes,


" NMA isn’t the only Boeing acronym you need to know. Say hello to FSA, the Future Small Airplane (not Future Single Aisle) the eventual replacement to the 737."

Jon Ostrower
-April 9, 2018.


https://mobile.twitter.com/jonostrower/ ... 3483242496

Regards

Jon Ostrower just wrote that FSA is the acronym of Future Small Airplane, not Future Single Aisle. He didn't mention whether it will be a narrowbody or a widebody.


Not "Futur Single Aisle" = not "Futur Narrowbody"

It's clear

No. You're wrong. Only you that are thinking that way. Other people including me think otherwise.
 
morrisond
Posts: 2859
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 12:23 pm

keesje wrote:
Checklist787 wrote:
DenverTed wrote:
I'm down with that program. One fuselage, two sets of wings, two models on each wing.


I like two different wings!
What are the disadvantages according to you ?


The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image


Exactly! a tight light Ovalish 7W that has only 25% more cross section than A320 for 16.7% more Y seats and 50% more J.

If they are aiming to replace 737 and 757 it does not make sense to create two cross sections.

A tight 6W won't work for 757 Replacement as I'm sure they will want to make something at least the size of the 753 and most likely larger and we know the 753 is hell on turnarounds and passenger experience.
 
morrisond
Posts: 2859
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 12:26 pm

FluidFlow wrote:
flipdewaf wrote:
FluidFlow wrote:

What are your thoughts on windows and doors (cabin and cargo). As the hoop stress will be largest in the area where windows and the lower part of the cabin door or the upper part of the cargo door is, all them structures have to be reinforced compared to a traditional tube as you have increased hoop stress on top of local stress fields caused by the doors and windows.

Smaller and less of them and rounder is better for weight purposes but more and bigger and sometime squarer is better for operations, comfort and regulations. I’m not sure on how these would realistically change their effect on a different shaped fuselage, it isn’t something I could figure out as an excel/JMP warrior.

Fred


Sent from my iPhone using Tapatalk


In a perfect infinite pressurized tube the stresses are equal everywhere but as soon as you cut a piece out (door) the stress will focus along the cut out because this area has to also carry the stresses the cut out cant handle any more. The more square the piece is the more focused the stress is at the corners. So far so good.

In a circular tube that is not a big problem anymore but if the tube is oval we have changing stresses along the cut out due to change in radius of the tube. From the shape this would increase towards the bottom of the passenger doors. There you would have maximum hoops stress from the shape and on top of that the stress from the cut out. This would mean that the structure in the vertex of the oval has to be reinforced meaning a substantial increase in weight while it can not effectively be thinned out at the top or you get there another stress focal point (if the stress is constant, thinner material needs to be stronger to accommodate for it). At the end you need a thinker tube if it is oval compared to a circular tube.

Interesting enough is that a standing oval is better (see 747/A380 and also the other tubes in use to a lesser extent), because the hoop stress focuses at the top and bottom where no other stresses are in play while the increased pressure stress at the side might be negative but the curvature of the features (doors, etc.) is smaller and therefore the stress focus by the cut out seems to be smaller.

So maybe it would be better for the NMA to be two floors with 3-2 on the bottom and 2-1 on the top floor and no cargo space at all. ;-)


Or half a circle on top and 1/3 of a larger one on the bottom joined at the floor beam so it's in tension vs compression.
 
FluidFlow
Posts: 737
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 12:42 pm

morrisond wrote:
FluidFlow wrote:
flipdewaf wrote:
Smaller and less of them and rounder is better for weight purposes but more and bigger and sometime squarer is better for operations, comfort and regulations. I’m not sure on how these would realistically change their effect on a different shaped fuselage, it isn’t something I could figure out as an excel/JMP warrior.

Fred


Sent from my iPhone using Tapatalk


In a perfect infinite pressurized tube the stresses are equal everywhere but as soon as you cut a piece out (door) the stress will focus along the cut out because this area has to also carry the stresses the cut out cant handle any more. The more square the piece is the more focused the stress is at the corners. So far so good.

In a circular tube that is not a big problem anymore but if the tube is oval we have changing stresses along the cut out due to change in radius of the tube. From the shape this would increase towards the bottom of the passenger doors. There you would have maximum hoops stress from the shape and on top of that the stress from the cut out. This would mean that the structure in the vertex of the oval has to be reinforced meaning a substantial increase in weight while it can not effectively be thinned out at the top or you get there another stress focal point (if the stress is constant, thinner material needs to be stronger to accommodate for it). At the end you need a thinker tube if it is oval compared to a circular tube.

Interesting enough is that a standing oval is better (see 747/A380 and also the other tubes in use to a lesser extent), because the hoop stress focuses at the top and bottom where no other stresses are in play while the increased pressure stress at the side might be negative but the curvature of the features (doors, etc.) is smaller and therefore the stress focus by the cut out seems to be smaller.

So maybe it would be better for the NMA to be two floors with 3-2 on the bottom and 2-1 on the top floor and no cargo space at all. ;-)


Or half a circle on top and 1/3 of a larger one on the bottom joined at the floor beam so it's in tension vs compression.


How would this work, at the floor beam there would be an abrupt change in curvature where stress would focus. This would transfer normal stress into a lot of shear stress at the joint. To accommodate this stress you would have to use heavy reinforced material.

It is all possible it is tho a question of economics. How can you make a weight and drag wise sub-optimal design economically viable? By making it big enough so the per seat drawback is minimal. So It would need way more payload range to reduce the impact of the drawbacks per seat. That is why the longer "stretched" versions are in general more economically viable.

To make the oval design better than a traditional NB it would have to be above the economically viable seat count for a single aisle so at least 250+ better 270+ in the smallest version and then you can stretch it to challenge the sub-optimal traditional WB designs (A330/B787-8). Sub 250 single class seats the aircraft is just too much structure for the mission (too heavy too much drag a lot of useless floor space (aisles)).
 
morrisond
Posts: 2859
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 1:16 pm

FluidFlow wrote:
morrisond wrote:
FluidFlow wrote:

In a perfect infinite pressurized tube the stresses are equal everywhere but as soon as you cut a piece out (door) the stress will focus along the cut out because this area has to also carry the stresses the cut out cant handle any more. The more square the piece is the more focused the stress is at the corners. So far so good.

In a circular tube that is not a big problem anymore but if the tube is oval we have changing stresses along the cut out due to change in radius of the tube. From the shape this would increase towards the bottom of the passenger doors. There you would have maximum hoops stress from the shape and on top of that the stress from the cut out. This would mean that the structure in the vertex of the oval has to be reinforced meaning a substantial increase in weight while it can not effectively be thinned out at the top or you get there another stress focal point (if the stress is constant, thinner material needs to be stronger to accommodate for it). At the end you need a thinker tube if it is oval compared to a circular tube.

Interesting enough is that a standing oval is better (see 747/A380 and also the other tubes in use to a lesser extent), because the hoop stress focuses at the top and bottom where no other stresses are in play while the increased pressure stress at the side might be negative but the curvature of the features (doors, etc.) is smaller and therefore the stress focus by the cut out seems to be smaller.

So maybe it would be better for the NMA to be two floors with 3-2 on the bottom and 2-1 on the top floor and no cargo space at all. ;-)


Or half a circle on top and 1/3 of a larger one on the bottom joined at the floor beam so it's in tension vs compression.


How would this work, at the floor beam there would be an abrupt change in curvature where stress would focus. This would transfer normal stress into a lot of shear stress at the joint. To accommodate this stress you would have to use heavy reinforced material.

It is all possible it is tho a question of economics. How can you make a weight and drag wise sub-optimal design economically viable? By making it big enough so the per seat drawback is minimal. So It would need way more payload range to reduce the impact of the drawbacks per seat. That is why the longer "stretched" versions are in general more economically viable.

To make the oval design better than a traditional NB it would have to be above the economically viable seat count for a single aisle so at least 250+ better 270+ in the smallest version and then you can stretch it to challenge the sub-optimal traditional WB designs (A330/B787-8). Sub 250 single class seats the aircraft is just too much structure for the mission (too heavy too much drag a lot of useless floor space (aisles)).


Yes stress would focus - but that is the strongest part of the cross section. At the part of the Aircraft where stresses are the most you would also have the Wingbox helping.

I'm not sure It would be that material, and it would be shorter as well potentially lowering the wetted surface area difference to being immaterial and potentially less for the same capacity (as 50% more J seats for the same length - you have to add a lot of length in an 6W to compensate for that). The math in terms of weight may be within low single digits in terms of difference. The stiffer skin would help as well.

There were strong rumors that Boeing had this figured out in 2010 - we are now basically 10 years past that with a lot better Computers to optimize the design.

My bet is on the 7W if they are replacing 737 and 757 at the same time.
 
morrisond
Posts: 2859
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 1:41 pm

morrisond wrote:
DenverTed wrote:
As far as the wing and engine combo, the NMA was about a 45K engine on a 45m wing. I imagine the FSA will downshift to a 35K engine on a 36m wing. Will they build a new CFRP wing with split winglets, or go with 2.5m folding wingtips for a 41m span?
In terms of MTOW, will it be 100t on a single axle like the A321, or move towards 125t with double axle like the 757?


I think if they build NMA/NSA on the same 7W cross section they would look like the following:

NSA -S 36M wing small wing - Engines up to about 32K - MTOW less than 737-9 - as less range and more fuel efficient doesn't have(can't because of the small wing) to carry as much fuel - call it 85T MTOW - Range 3,300ish (don't make it to much to start to maximize efficiency and have room to grow.
NSA-L Same as above - maybe a small thrust bump and 87-88T MTOW

NMA-S 42-43M Wing - whatever they can fold to 36M to fit in same gates as NSA - Engines in the 45K range - Range about 5,300NM 105-110T MTOW
NMA-L same as NMA-S - Engines maybe 47-48K - Range about 4,800NM 110-115T MTOW

Lean and Mean


Actually where it could get really interesting is if Boeing Brazil does do an 5W fuselage at about the same time - probably Carbon for sufficient length using NSA/NMA cockpit/control/systems architecture.

It would have it's own wing (scaled down from the NSA wing) for the smaller versions and optimized for shorter stage lengths - let's call this the New Brazil Airplane (NBA)

NBA -S 36M small wing - 150 seats one class to maximize use of flight attendants - 3,000NM range 65T MTOW (A221 is 63T A223 is 70T)

NBA-L - 36M small Wing 180 seats one class (A220-500 size) - 2,800NM range 68T MTOW


Then you could potentially bolt the NSA wing on the 5W to get an 5,000NM Hub Bypass option in NBA-L size at an MTOW of about 85T using NSA main gear and Engines.

As the systems would be the same if should be relatively straightforward - probably a new wingbox as the size at the root of the wing would be very different and the loads a lot more.

Just an idea. Two Fuselage Cross Sections (5W and 7W), three wings (NBA, NSA, NMA), three sets of gear and Program accounting = amazing combinations of airplanes with different capabilities and an incredible way forward with Development amortized over 10,000+ frames.

Massive commonality in terms of Maintenance and training.
 
FluidFlow
Posts: 737
Joined: Wed Apr 10, 2019 6:39 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 2:27 pm

morrisond wrote:
FluidFlow wrote:
morrisond wrote:

Or half a circle on top and 1/3 of a larger one on the bottom joined at the floor beam so it's in tension vs compression.


How would this work, at the floor beam there would be an abrupt change in curvature where stress would focus. This would transfer normal stress into a lot of shear stress at the joint. To accommodate this stress you would have to use heavy reinforced material.

It is all possible it is tho a question of economics. How can you make a weight and drag wise sub-optimal design economically viable? By making it big enough so the per seat drawback is minimal. So It would need way more payload range to reduce the impact of the drawbacks per seat. That is why the longer "stretched" versions are in general more economically viable.

To make the oval design better than a traditional NB it would have to be above the economically viable seat count for a single aisle so at least 250+ better 270+ in the smallest version and then you can stretch it to challenge the sub-optimal traditional WB designs (A330/B787-8). Sub 250 single class seats the aircraft is just too much structure for the mission (too heavy too much drag a lot of useless floor space (aisles)).


Yes stress would focus - but that is the strongest part of the cross section. At the part of the Aircraft where stresses are the most you would also have the Wingbox helping.

I'm not sure It would be that material, and it would be shorter as well potentially lowering the wetted surface area difference to being immaterial and potentially less for the same capacity (as 50% more J seats for the same length - you have to add a lot of length in an 6W to compensate for that). The math in terms of weight may be within low single digits in terms of difference. The stiffer skin would help as well.

There were strong rumors that Boeing had this figured out in 2010 - we are now basically 10 years past that with a lot better Computers to optimize the design.

My bet is on the 7W if they are replacing 737 and 757 at the same time.


So we have 10 years and no business case yet, might have another 10 years more for that. 7W just does not work, too heavy for the market. Who buys an aircraft that has 50% more J capacity? No euro airline, because for an aircraft you propose is optimized for <3500nm range you have euro business, no J necessary. No LCC or ULCC does care about J potential. Have a look through the 737 and A320 order book and check out who actually puts proper J seats in their orders. 10% of the order maybe. So you have too much aircraft for almost all your customers. Why does the 787 perform so much better in sales than the 777 even tho it has only 3-3-3 seating? The 777 is way too much aircraft. Thats why the A330 is even worse, while the smaller cabin could be an advantage over the 787 if it would be lighter, it is too heavy and therefore too much aircraft.

If a future 200 pax single aisle can lift 20t and a 200 pax twin aisle can lift 20t over the same distance, the lighter one will be better and by pure physics the single aisle will be lighter and also have less drag. It would have to lift more pax or payload to justify more weight and drag.

You can not beat the physics behind aviation. If the NMA 7W concept would be so good and so amazing it would already be on sale but it is not what speaks volumes. In 61 days its 2020. I bet we will not see an announcement for any new design before 2023 the earliest and it will not be a combo product. Too much risk, and no one takes risks in a duopoly. Better be conservative and keep your 50% share than try to shoot for >60% and land risk landing at <40%
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 2:43 pm

Checklist787 wrote:
Other people like you MUST
Re-read the tweet of J. Ostrower.. :bouncy:


And you MUST read the damn article linked in that very tweet.
I was raised by a cup of coffee.
 
morrisond
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 2:58 pm

FluidFlow wrote:
morrisond wrote:
FluidFlow wrote:

How would this work, at the floor beam there would be an abrupt change in curvature where stress would focus. This would transfer normal stress into a lot of shear stress at the joint. To accommodate this stress you would have to use heavy reinforced material.

It is all possible it is tho a question of economics. How can you make a weight and drag wise sub-optimal design economically viable? By making it big enough so the per seat drawback is minimal. So It would need way more payload range to reduce the impact of the drawbacks per seat. That is why the longer "stretched" versions are in general more economically viable.

To make the oval design better than a traditional NB it would have to be above the economically viable seat count for a single aisle so at least 250+ better 270+ in the smallest version and then you can stretch it to challenge the sub-optimal traditional WB designs (A330/B787-8). Sub 250 single class seats the aircraft is just too much structure for the mission (too heavy too much drag a lot of useless floor space (aisles)).


Yes stress would focus - but that is the strongest part of the cross section. At the part of the Aircraft where stresses are the most you would also have the Wingbox helping.

I'm not sure It would be that material, and it would be shorter as well potentially lowering the wetted surface area difference to being immaterial and potentially less for the same capacity (as 50% more J seats for the same length - you have to add a lot of length in an 6W to compensate for that). The math in terms of weight may be within low single digits in terms of difference. The stiffer skin would help as well.

There were strong rumors that Boeing had this figured out in 2010 - we are now basically 10 years past that with a lot better Computers to optimize the design.

My bet is on the 7W if they are replacing 737 and 757 at the same time.


So we have 10 years and no business case yet, might have another 10 years more for that. 7W just does not work, too heavy for the market. Who buys an aircraft that has 50% more J capacity? No euro airline, because for an aircraft you propose is optimized for <3500nm range you have euro business, no J necessary. No LCC or ULCC does care about J potential. Have a look through the 737 and A320 order book and check out who actually puts proper J seats in their orders. 10% of the order maybe. So you have too much aircraft for almost all your customers. Why does the 787 perform so much better in sales than the 777 even tho it has only 3-3-3 seating? The 777 is way too much aircraft. Thats why the A330 is even worse, while the smaller cabin could be an advantage over the 787 if it would be lighter, it is too heavy and therefore too much aircraft.

If a future 200 pax single aisle can lift 20t and a 200 pax twin aisle can lift 20t over the same distance, the lighter one will be better and by pure physics the single aisle will be lighter and also have less drag. It would have to lift more pax or payload to justify more weight and drag.

You can not beat the physics behind aviation. If the NMA 7W concept would be so good and so amazing it would already be on sale but it is not what speaks volumes. In 61 days its 2020. I bet we will not see an announcement for any new design before 2023 the earliest and it will not be a combo product. Too much risk, and no one takes risks in a duopoly. Better be conservative and keep your 50% share than try to shoot for >60% and land risk landing at <40%


Then there really is no need to replace the 737 then.

So how much heavier do you suppose a 7W is over a 6W at the same Capacity using Carbon? Due to the unique properties of Carbon Physics may say the barrel is within a few percent per seat one way or another. The Barrel is a small fraction of the MTOW making the effect on efficiency even smaller.

So what do you suppose then they will do a 6W and then an 8W at some point or ignore that part of the market altogether?

NMA is delayed by MAX. Boeing was ready to announce it. I doubt it will be a combo either - they would be stupid to announce NSA based on NMA so soon until closer to 2030 as it could cannibalize 737 sales. NMA will go first.
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:01 pm

morrisond wrote:
keesje wrote:
Checklist787 wrote:

I like two different wings!
What are the disadvantages according to you ?


The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image


Exactly! a tight light Ovalish 7W that has only 25% more cross section than A320 for 16.7% more Y seats and 50% more J.

If they are aiming to replace 737 and 757 it does not make sense to create two cross sections.

A tight 6W won't work for 757 Replacement as I'm sure they will want to make something at least the size of the 753 and most likely larger and we know the 753 is hell on turnarounds and passenger experience.


This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:23 pm

keesje wrote:
morrisond wrote:
keesje wrote:

The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image


Exactly! a tight light Ovalish 7W that has only 25% more cross section than A320 for 16.7% more Y seats and 50% more J.

If they are aiming to replace 737 and 757 it does not make sense to create two cross sections.

A tight 6W won't work for 757 Replacement as I'm sure they will want to make something at least the size of the 753 and most likely larger and we know the 753 is hell on turnarounds and passenger experience.


This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image



Yes - I know yours is an SAXW - but that makes the math even harder over how it may have an advantage over a tight 7W - which would be about the same height and only about 20 inches wider for 2-2-2 in front for longer flights.
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:30 pm

morrisond wrote:
FluidFlow wrote:
morrisond wrote:

Yes stress would focus - but that is the strongest part of the cross section. At the part of the Aircraft where stresses are the most you would also have the Wingbox helping.

I'm not sure It would be that material, and it would be shorter as well potentially lowering the wetted surface area difference to being immaterial and potentially less for the same capacity (as 50% more J seats for the same length - you have to add a lot of length in an 6W to compensate for that). The math in terms of weight may be within low single digits in terms of difference. The stiffer skin would help as well.

There were strong rumors that Boeing had this figured out in 2010 - we are now basically 10 years past that with a lot better Computers to optimize the design.

My bet is on the 7W if they are replacing 737 and 757 at the same time.


So we have 10 years and no business case yet, might have another 10 years more for that. 7W just does not work, too heavy for the market. Who buys an aircraft that has 50% more J capacity? No euro airline, because for an aircraft you propose is optimized for <3500nm range you have euro business, no J necessary. No LCC or ULCC does care about J potential. Have a look through the 737 and A320 order book and check out who actually puts proper J seats in their orders. 10% of the order maybe. So you have too much aircraft for almost all your customers. Why does the 787 perform so much better in sales than the 777 even tho it has only 3-3-3 seating? The 777 is way too much aircraft. Thats why the A330 is even worse, while the smaller cabin could be an advantage over the 787 if it would be lighter, it is too heavy and therefore too much aircraft.

If a future 200 pax single aisle can lift 20t and a 200 pax twin aisle can lift 20t over the same distance, the lighter one will be better and by pure physics the single aisle will be lighter and also have less drag. It would have to lift more pax or payload to justify more weight and drag.

You can not beat the physics behind aviation. If the NMA 7W concept would be so good and so amazing it would already be on sale but it is not what speaks volumes. In 61 days its 2020. I bet we will not see an announcement for any new design before 2023 the earliest and it will not be a combo product. Too much risk, and no one takes risks in a duopoly. Better be conservative and keep your 50% share than try to shoot for >60% and land risk landing at <40%


Then there really is no need to replace the 737 then.

So how much heavier do you suppose a 7W is over a 6W at the same Capacity using Carbon? Due to the unique properties of Carbon Physics may say the barrel is within a few percent per seat one way or another. The Barrel is a small fraction of the MTOW making the effect on efficiency even smaller.

So what do you suppose then they will do a 6W and then an 8W at some point or ignore that part of the market altogether?

NMA is delayed by MAX. Boeing was ready to announce it. I doubt it will be a combo either - they would be stupid to announce NSA based on NMA so soon until closer to 2030 as it could cannibalize 737 sales. NMA will go first.


If we assume same technology for the 6W and the 7W, so both carbon, optimised for the same pax count (7W a bit shorter but wider), i say +5t. 0.5t from the bigger cabin floor, 1t from the bigger tail section, 2.5t the fuselage, 1t from the bigger engines (only slightly bigger, but needed due to the additional drag).

I think they will do a 7.5W NMA (giving the options to either have a bit more space with 7W or the option to go full ULCC 8W), with two versions max capacity 272/336pax at @70cm' pitch with 8W seating or 238/294 in 7W. This would not be tight 7W but really tight 8W, 2x50cm aisle and 8x45cm seats (including arm rests). cabin width of 460cm (60cm less than the A330). Maximum diameter would be 490cm (70cm less than the A330).

This would give maximum flexibility for configuration. 1-1-1/1-2-1 J, 2/2/2 or 2/3/2 W and 2/3/2 or 2/4/2 J. Really versatile.

Then just produce a simple 6W carbon 737 replacement in 2030+ with the main goal of being dirt cheap to buy, with the top (longest) version right underneath the NMA and the smallest version above the E195-2
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:37 pm

keesje wrote:
morrisond wrote:
keesje wrote:

The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image


Exactly! a tight light Ovalish 7W that has only 25% more cross section than A320 for 16.7% more Y seats and 50% more J.

If they are aiming to replace 737 and 757 it does not make sense to create two cross sections.

A tight 6W won't work for 757 Replacement as I'm sure they will want to make something at least the size of the 753 and most likely larger and we know the 753 is hell on turnarounds and passenger experience.


This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image

168"? A 707, 737 is 148", so 168" is room for another aisle with the same width seats. Or a wider aisle and wider seats as you propose. I was thinking 172" width for a 2-2-2 with 18" seats.
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:42 pm

morrisond wrote:
keesje wrote:
morrisond wrote:

Exactly! a tight light Ovalish 7W that has only 25% more cross section than A320 for 16.7% more Y seats and 50% more J.

If they are aiming to replace 737 and 757 it does not make sense to create two cross sections.

A tight 6W won't work for 757 Replacement as I'm sure they will want to make something at least the size of the 753 and most likely larger and we know the 753 is hell on turnarounds and passenger experience.


This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image



Yes - I know yours is an SAXW - but that makes the math even harder over how it may have an advantage over a tight 7W - which would be about the same height and only about 20 inches wider for 2-2-2 in front for longer flights.


A 7 abreast cabin would add 30inch (1 seat, 0.5 aisle) to the cross section, while still not be able to carry the LD3 of WB's, and passengers would not being be able to pass each other in the aisles.

It's drag / frontal area would significant bigger and so it's tail, because it would be a stubbier fuselage at the same seat capacity. And carry a few less AKH containers too because of it.

:arrow: Over the many MOM/NMA years, I have never seen any evidence that an oval 2-3-2 cross section would be more efficient for short/medium flights than a longer circular 6W cabin. The airlines neither it seems & they told Boeing..

Image
Last edited by keesje on Fri Nov 01, 2019 3:46 pm, edited 2 times in total.
"Never mistake motion for action." Ernest Hemingway
 
DenverTed
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:44 pm

On floor stresses, in a double bubble or 8 shape, the hoop stresses angle outward and pull on the floor in tension, correct? And in a lemon shape with flat circle on top and bottom, the hoop stresses angle inward and pull on the floor in compression? Isn't that what Jon Ostrower reported Boeing was thinking about, a half circle on top, and a flatter circular chord bottom that would pull on the floor in compression. Not to mention that the cargo lobe has struts, so I would assume that one could put an inward kinks in the fuselage at the struts and load them in tension (just like the double bubble), or an outward kink where two flatter radii come together and load the struts in compression.
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 3:48 pm

keesje wrote:
morrisond wrote:
keesje wrote:

This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image



Yes - I know yours is an SAXW - but that makes the math even harder over how it may have an advantage over a tight 7W - which would be about the same height and only about 20 inches wider for 2-2-2 in front for longer flights.


A 7 abreast cabin would add 30inch (1 seat, 0.5 aisle) to the cross section, while still not be able to carry the LD3 of WB's, and passengers would not being be able to pass each other in the aisles.

It's drag / frontal area would significant bigger and so it's tail, because it would be a stubbier fuselage at the same seat capacity. And carry a few less AKH containers too because of it.

:arrow: Over the many MOM/NMA years, I have never seen any evidence that an oval 2-3-2 cross section would be more efficient for short/medium flights than a longer circular 6W cabin. The airlines neither it seems & they told Boeing..

Image

64t and 43m? An A321 with a wider aisle at 64t? What's not to like.
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 4:07 pm

DenverTed wrote:
keesje wrote:
morrisond wrote:


Yes - I know yours is an SAXW - but that makes the math even harder over how it may have an advantage over a tight 7W - which would be about the same height and only about 20 inches wider for 2-2-2 in front for longer flights.


A 7 abreast cabin would add 30inch (1 seat, 0.5 aisle) to the cross section, while still not be able to carry the LD3 of WB's, and passengers would not being be able to pass each other in the aisles.

It's drag / frontal area would significant bigger and so it's tail, because it would be a stubbier fuselage at the same seat capacity. And carry a few less AKH containers too because of it.

:arrow: Over the many MOM/NMA years, I have never seen any evidence that an oval 2-3-2 cross section would be more efficient for short/medium flights than a longer circular 6W cabin. The airlines neither it seems & they told Boeing..

Image

64t and 43m? An A321 with a wider aisle at 64t? What's not to like.


The short haul versions of such an aircraft would be fully optimized for short flights, up to ~4 hrs. Not 4000NM+ like the A321.

Image
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 4:27 pm

I seem to remember that back around 2005 or 2006, Boeing started hinting that it was considering a new narrowbody as a successor to the 737, as well as the 757-200. A friend of mine at AA told me that both AA and Southwest expressed interest. AA needed a plane to replace the retired F100 fleet. The 727's retirement had been pushed up due to 9/11. And the oldest MD-80s were more than 20 years old.

But, with the problems with the 787 and the 747-8, preliminary work on the new narrowbody ended. AA wound up ordering more 737-800s, in part because of the run-up in oil prices in 2007 and 2008. AA needed more narrowbodies with better fuel economy to replace the MD-80s on longer routes, like ORD-SEA and DFW-BOS.

Boeing wanted to devise a revolutionary aircraft, i.e., an all composite airplane. At the same time. it wanted to manufacture fewer parts and sub-assemblies in-house. I believe that Boeing was trying to do too much with the 787 program. If it had simply gone with the all-composite aircraft, while waiting for the new narrowbody to change how Boeing assembled got parts and sub-assemblies manufactured and assembled, then the 787 would not have been as badly delayed as it was, and Boeing would have had a new narrowbody that might have forced Airbus to seriously consider whether to go with the A320 neo or design a new narrowbody of its own.

Remember that Airbus thought it could take the 787's engines and hang them on an updated A330 airframe. The market forced Airbus to come up with the A350.
 
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 4:53 pm

morrisond wrote:

Two Fuselage Cross Sections (5W and 7W), three wings (NBA, NSA, NMA), three sets of gear and Program accounting = amazing combinations of airplanes with different capabilities and an incredible way forward with Development amortized over 10,000+ frames.

Massive commonality in terms of Maintenance and training.


Okay, now, we know why you not like one unique wing.

3 different fuselages cross section for a potentiel of +10.000 frames. Game changers in different Payload-range

It'g good but the problems are,

1. Now Boeing want make the 767-X above the Middle Of Market

2. The FSA concept will should replace the 757 in the bottom of the Middle Of Market

3. Enter into service for the upcoming 737MAX-10 and the launch of the forthcoming 737MAX-9ERX not means reality for a replacement of the popular narrowbody before 2030.

I bet than Boeing had re-rewied it's strategy with the FSA over the NMA, because the 767-X in the above of the Middle Of Market revealed by flightglobal proves that the FSA is a smaller than the NMA who' s in the bottom to "replace" the NMA-6 concept who was not the priority according to Boeing recently.

At this effect, it's possible that the bottom of the Middle Of Market who' s MORE important, must answered by another idea, by the FSA-6X (a Smaller Twin-Aisles)

So, we can see clearly,

The FSA will be built in two versions with a theorical/ traditional baseline, the FSA-8 and the Strech FSA-9.

The FSA-8 flying farther than the forthcoming 737MAX-10, but as far as the upcoming 737MAX-9ERX but the last is not the same size like the FSA-8 because in a 2-class seating the business seat will be (IMO) @ 36in pitch to compare orange-to-orange for the LCC missions. It's for why i think Boeing re-fit it's strategy with the FSA over the NMA in the bottom of the market with the 737MAX-9ER/-10 and the FSA-6X concept.

The same thing for the 767-X based on the - 400ER size, and the Strech-FSA-9 will seating each others with few difference of pax.
A 2-class 280 seats for the 767-X and 2-class 265 seats with business seat @ 36 in pitch Apple-to-Apple comparison.

It's for what there is MANY reasons to believe that the FSA is a true Middle Of Market aircraft in term of capacity of seats thanks to it's Twin-Aisles characteristics.

I bet for this strategy of Boeing!

Single Aisle zone
737-7
737-8
737-9/-9ER

Middle Of Market zone
737-10/FSA-8X (757 replacement)
FSA-9/767X (A332/-800 replacement)
787-8 (considered by Boeing as a Small Airplane /Study Market)
A330-200/-800neo

Middle Size Airplane zone
787-9
A330-300/-900neo
777-200/-ER/-LR
A350-900/ULR/R
787-10
A350-1000
777-300/-ER
777-8X

Big Airplane /VLA zone
777-9X
747-8I
A380-800

morrisond wrote:
My bet is on the 7W if they are replacing 737 and 757 at the same time


Do you think an ovalish 6W could be most efficient over an ovalish 7W?

I suspected that the new strategic FSA concept is an efficient ovalish 6W.

Regards
Last edited by Checklist787 on Fri Nov 01, 2019 5:20 pm, edited 3 times in total.
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 4:55 pm

morrisond wrote:

So how much heavier do you suppose a 7W is over a 6W at the same Capacity using Carbon? Due to the unique properties of Carbon Physics may say the barrel is within a few percent per seat one way or another. The Barrel is a small fraction of the MTOW making the effect on efficiency even smaller.



So the problem with the reasoning behind the fuselage being only a small part (let’s say 10% of MTOW) is the the aircraft has to be designed to perform a particular mission (payload/range).with the added fuselage weight you are either not going to make your mission or have to sale up everything else with the fuselage mass. If we reverse the maths and instead of saying the fuselage is 10% of MTOW and we say that MTOW is 10x fuselage weight for a given mission. The gains of reduced wetted area of the ovoid will be entirely mitigated by a larger wing required to lift the heavier dead weight.

As fluidflow says, the physics really doesn’t like ovals in this orientation.

Fred


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flipdewaf
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 5:06 pm

Checklist787 wrote:

Do you think an ovalish 6W could be most efficient over an ovalish 7W?

Regards
depends on payload requirements.

But it’s an odd question because oval isn’t the right thing in either scenario.

Wanna eat turd flavoured chocolate or chocolate flavoured turd?

Fred



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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 5:11 pm

flipdewaf wrote:
morrisond wrote:

So how much heavier do you suppose a 7W is over a 6W at the same Capacity using Carbon? Due to the unique properties of Carbon Physics may say the barrel is within a few percent per seat one way or another. The Barrel is a small fraction of the MTOW making the effect on efficiency even smaller.



So the problem with the reasoning behind the fuselage being only a small part (let’s say 10% of MTOW) is the the aircraft has to be designed to perform a particular mission (payload/range).with the added fuselage weight you are either not going to make your mission or have to sale up everything else with the fuselage mass. If we reverse the maths and instead of saying the fuselage is 10% of MTOW and we say that MTOW is 10x fuselage weight for a given mission. The gains of reduced wetted area of the ovoid will be entirely mitigated by a larger wing required to lift the heavier dead weight.

As fluidflow says, the physics really doesn’t like ovals in this orientation.

Fred

Sent from my iPhone using Tapatalk


I don't disagree - if the 6W is lighter per seat. If it is withing 1-3% it might not be that bad.

Theoretically you might be able to get by with a smaller wing as well as the flatter/wider body could act as more of an lifting surface.

Moving away from a traditional Round tube and wings could have some interesting effects.

Not everything may scale up.
Last edited by morrisond on Fri Nov 01, 2019 5:13 pm, edited 1 time in total.
 
Checklist787
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 5:13 pm

keesje wrote:
morrisond wrote:
keesje wrote:

The challenge would be to have a fuselage cross section that adds value for medium flight but also is efficient short haul.

Image


Exactly! a tight light Ovalish 7W that has only 25% more cross section than A320 for 16.7% more Y seats and 50% more J.

If they are aiming to replace 737 and 757 it does not make sense to create two cross sections.

A tight 6W won't work for 757 Replacement as I'm sure they will want to make something at least the size of the 753 and most likely larger and we know the 753 is hell on turnarounds and passenger experience.


This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image


Not bad IMO

An additional of only 4-6in would have allowed twin aisles of 17" or 18" IMO.
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morrisond
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 5:19 pm

keesje wrote:
morrisond wrote:
keesje wrote:

This concept was more a spacy 6W (1.5 aisle) to pass other passengers during deboarding (with 2 narrow aisles you can't still pass anyone), while being much lighter and enabling 1-2-1 or 1-1-1 in front for longer flights.

Image



Yes - I know yours is an SAXW - but that makes the math even harder over how it may have an advantage over a tight 7W - which would be about the same height and only about 20 inches wider for 2-2-2 in front for longer flights.


A 7 abreast cabin would add 30inch (1 seat, 0.5 aisle) to the cross section, while still not be able to carry the LD3 of WB's, and passengers would not being be able to pass each other in the aisles.

It's drag / frontal area would significant bigger and so it's tail, because it would be a stubbier fuselage at the same seat capacity. And carry a few less AKH containers too because of it.

:arrow: Over the many MOM/NMA years, I have never seen any evidence that an oval 2-3-2 cross section would be more efficient for short/medium flights than a longer circular 6W cabin. The airlines neither it seems & they told Boeing..

Image


I would assume a tight 7W would be no more than the Width of an 737 (148Inches) plus at MAX another 40 Max - maybe a few less as two aisles could be made tighter than the 737 Aisle.

As the cross section would be used across NMA/NSA a new container that is 30 inches + wider in the middle than an AKH would have a good 30% more volume - much less than the decrease in length of the plane.
 
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PW100
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Fri Nov 01, 2019 10:59 pm

Checklist787 wrote:
PW100 wrote:
Checklist787 wrote:
Hi!
Yes,
" NMA isn’t the only Boeing acronym you need to know. Say hello to FSA, the Future Small Airplane (not Future Single Aisle) the eventual replacement to the 737."
Jon Ostrower
-April 9, 2018.
https://mobile.twitter.com/jonostrower/ ... 3483242496
Regards


I may be mistaken, but apparently it also is not called NNWB . . .





New Narrow Wide Body


Congratulations!!!

Finally a person who CAN read.

Another opinion or someone who knows how to interpret again?


Thanks!


You manage to totally misread my post, and then drawing incorrect conclusions.
But, hey, that's what keeps this thread going for some time now. So not really surprising after all . . .
Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
 
RJMAZ
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 4:37 am

morrisond wrote:
So what do you suppose then they will do a 6W and then an 8W at some point or ignore that part of the market altogether?

The 757-300 seats more people in 6W than the A310 in 8W.

There is no market being ignored by skipping the very inefficient, overweight 7W.

I'll pre-empt your next highly obvious comeback that you'll say the A310 was a failure as it sold 255 aircraft. You will use this as proof that 8ab can not cover that size. But you will fail to put that number into perspective. When the A310 first flew Airbus had only ever built 200 aircraft in total as an entire company in the previous 10 years. Airbus was only just building a good track record for itself. Today we have 11 times as many passenger miles per year as we did in 1982.

Lets run a hypothetical and assume Airbus had the solid reputation in 1982 that it does today, it would have easily sold twice as many A310's or 510 aircraft in total. If the market in 1982 was 11 times larger as it is today that would have meant 5,610 A310's sold.

The A310 was very successful.

Take the A310 cross section, reduce the cabin width by a foot so airlines can't squeeze in 9abreast. Then reduce the fuselage height by a couple feet to go from LD3 containers to a new reduced height full width container. The results is an aircraft that would look less stubby than the A310 just like the Boeing powerpoint pictures for the NMA/797. This is the perfect size to transition from the 737-10 with about 25%. Then a further stretch to have 40% more seats than the 737-10. Pretty simple.
 
benbeny
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 4:48 am

Can't Boeing just give 737 new wings and taller landing gear, slap a new name, and call it a day?
 
RJMAZ
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 5:07 am

benbeny wrote:
Can't Boeing just give 737 new wings and taller landing gear, slap a new name, and call it a day?

The A300, A310, A330 and A340 all used the same fuselage cross section with different fuselage lengths, wings sizes and landing gear heights.

So it would be possible to use the 737 fuselage tube again for a future aircraft and do the same process. Would the aircraft be competitive?

Using the 737 tube you would really want to keep it under 240 seats. The 757-300 had very long boarding times, ideally it needed a wider aisle which would require a wider cross section than the 737. The MC-21 cross section would be perfect for a 757-300 fuselage length as it has an extra foot of width. Many people have mentioned the wide aisle idea.
 
aden23
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 6:08 am

Boeing has absolutely no business building new aircraft. Period. The criminal in charge of Boeing admitted this week to knowingly sending people to their deaths because money is more important to him than human life.

Why would anyone think a group of criminals would be able to lead the design of a new plane? It’s absolutely laughable.
 
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scbriml
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 7:57 am

Checklist787 wrote:
2.Launching the FSA


I suspect you're in for a big disappointment if you think Boeing is launching the single-aisle Future Small Airplane 737 replacement next year.
Time flies like an arrow. Fruit flies like a banana!
There are 10 types of people in the World - those that understand binary and those that don't.
 
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Momo1435
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 9:31 am

Much to do about nothing.

In the last couple of years the idea of a small 2 aisle Boeing plane to replace/as an alternative to the 737 has floated around on several aviation websites.

It's a concept that has been looked at by Boeing. But that was in a completely different time before the MAX crashes. Boeing would be very stupid if they don't look at all the options right now, a quick replacement of the 737 MAX will be talked about with their customers.

So we should also have an open discussion about all the options. There's absolutely no reason to argue about decissions that have not yet been made as if they are solid facts. So please chill everybody and have a normal civilized discussion.
 
juliuswong
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 9:39 am

Hi all, this thread will be locked for cleaning and released for future comment. Kindly note that all moderators are working in voluntary basis and we have our full time job, hence we are not here to monitor all day. Thank you to those who have filed report.
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juliuswong
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 10:01 am

Clean-up completed. Thread unlocked for further comment.
- Life is a journey, travel it well -
 
flipdewaf
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 10:05 am

juliuswong wrote:
Clean-up completely. Thread unlocked for further comment.

Thanks!


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morrisond
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 10:48 am

RJMAZ wrote:
morrisond wrote:
So what do you suppose then they will do a 6W and then an 8W at some point or ignore that part of the market altogether?

The 757-300 seats more people in 6W than the A310 in 8W.

There is no market being ignored by skipping the very inefficient, overweight 7W.

I'll pre-empt your next highly obvious comeback that you'll say the A310 was a failure as it sold 255 aircraft. You will use this as proof that 8ab can not cover that size. But you will fail to put that number into perspective. When the A310 first flew Airbus had only ever built 200 aircraft in total as an entire company in the previous 10 years. Airbus was only just building a good track record for itself. Today we have 11 times as many passenger miles per year as we did in 1982.

Lets run a hypothetical and assume Airbus had the solid reputation in 1982 that it does today, it would have easily sold twice as many A310's or 510 aircraft in total. If the market in 1982 was 11 times larger as it is today that would have meant 5,610 A310's sold.

The A310 was very successful.

Take the A310 cross section, reduce the cabin width by a foot so airlines can't squeeze in 9abreast. Then reduce the fuselage height by a couple feet to go from LD3 containers to a new reduced height full width container. The results is an aircraft that would look less stubby than the A310 just like the Boeing powerpoint pictures for the NMA/797. This is the perfect size to transition from the 737-10 with about 25%. Then a further stretch to have 40% more seats than the 737-10. Pretty simple.


You might be right on NMA - but the topic of this thread was Boeing looking to replace the 737 and 757 - how is an 8W going to replace a 737?

People keep throwing around the inefficient Heavy 7W tube. We don't really know what you could accomplish with Carbon - the inherent stiffness of a carbon skin that needs to be a certain thickness for impact strength could solve a lot of issues in an 7W tube.

As I have showed multiple times the cross section increase per seat is no that bad in Y and an advantage in W. It's no more than the delta between the A320 and 737 cross section.

There may be some reason Boeing might have been contemplating 7W with NSA originally - or do you think they have not gotten better at Carbon design and understanding in the past 10 years? More complex structures are possible. Computing abilities have not been getting worse.

I doubt shear stresses at the Floor with 1/2 a circle on top and 1/3 of one on the bottom (or something like that) would be that big of an issue with the computing ability we have these days.

On the top half then you use something like Boeing's 777x rib design to eke out more shoulder room.

I believe aircraft design is about to evolve very quickly beyond the slide ruler.
 
morrisond
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 10:55 am

RJMAZ wrote:
benbeny wrote:
Can't Boeing just give 737 new wings and taller landing gear, slap a new name, and call it a day?

The A300, A310, A330 and A340 all used the same fuselage cross section with different fuselage lengths, wings sizes and landing gear heights.

So it would be possible to use the 737 fuselage tube again for a future aircraft and do the same process. Would the aircraft be competitive?

Using the 737 tube you would really want to keep it under 240 seats. The 757-300 had very long boarding times, ideally it needed a wider aisle which would require a wider cross section than the 737. The MC-21 cross section would be perfect for a 757-300 fuselage length as it has an extra foot of width. Many people have mentioned the wide aisle idea.


And if you assume that in an 7W and it's packed in tight like a 737 and two narrow aisles in Y using 737 seats - for not much more width you get an extra seat in there. The MC-21 is 160" wide. Keep the same fuselage Height and bulge out the sides 10-14" on each side and you get that extra Y seat and 2 more up front in W. Plus a much wider container down below which could have 40-50%+ more internal volume.
 
flipdewaf
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Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 11:00 am

Is it faster to load/unload with two aisles or a wider aisle? If an aisle is blocked you cannot just use the other one.

Fred


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Image
 
benbeny
Posts: 240
Joined: Thu Nov 03, 2016 1:44 pm

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 12:21 pm

RJMAZ wrote:
benbeny wrote:
Can't Boeing just give 737 new wings and taller landing gear, slap a new name, and call it a day?

The A300, A310, A330 and A340 all used the same fuselage cross section with different fuselage lengths, wings sizes and landing gear heights.

So it would be possible to use the 737 fuselage tube again for a future aircraft and do the same process. Would the aircraft be competitive?

Using the 737 tube you would really want to keep it under 240 seats. The 757-300 had very long boarding times, ideally it needed a wider aisle which would require a wider cross section than the 737. The MC-21 cross section would be perfect for a 757-300 fuselage length as it has an extra foot of width. Many people have mentioned the wide aisle idea.

Never thought about the boarding time. Thanks!
 
benbeny
Posts: 240
Joined: Thu Nov 03, 2016 1:44 pm

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 12:23 pm

flipdewaf wrote:
Is it faster to load/unload with two aisles or a wider aisle? If an aisle is blocked you cannot just use the other one.

Fred


Sent from my iPhone using Tapatalk

Twin aisle gives you redundancy, but in the end, the limiting factor is often the door size and how fast people walk down the bridge. How often it is when you have to wait for last one pax?
 
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EA CO AS
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Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 12:39 pm

keesje wrote:

Image


What does this look like in two-class configuration?
"In this present crisis, government is not the solution to our problem - government IS the problem." - Ronald Reagan

Comments made here are my own and are not intended to represent the official position of Alaska Air Group
 
flipdewaf
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Joined: Thu Jul 20, 2006 6:28 am

Re: Boeing NMA in doubt as customers push for all new 737MAX and 757 replacement

Sat Nov 02, 2019 12:40 pm

benbeny wrote:
flipdewaf wrote:
Is it faster to load/unload with two aisles or a wider aisle? If an aisle is blocked you cannot just use the other one.

Fred


Sent from my iPhone using Tapatalk

Twin aisle gives you redundancy, but in the end, the limiting factor is often the door size and how fast people walk down the bridge. How often it is when you have to wait for last one pax?

In 7w you only have redundancy for the middle seat and that only counts if you haven’t yet entered the aisle. A wider single aisle might mean that you can squeeze by a stopped person or it might mean that people just take up more room when they swing their bags.

Fred


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