The reasoning is wrong, because the load distribution caused by the geometry does not change with the material used to build the fuselage. The relative difference between both designs using the same material remains quite static. Sure you could do a CFRP ovid fuselage that is competitive to a conventional metal fuselage, but that is not an effective solution for a new plane.
Would you care to add some reasoning as to why it's not that effective?
Because your new design would be inferior to a circular or double bubble design using the same construction methods. In addition the basic geometric disadvantage of the 7 abreast seating stays with you. Sure this might be the most efficient 7 abreast design, if you do not want to have a cargo carrying capacity, but the overall design is still less efficient than a conventional 6 or 8 abreast.
So in the end you move to the most modern fuselage construction technique to get you fuselage weight down by 25% compared to a old style metal tube and then you give up 30% of this due to your ovid shape and probably more than the rest due to your ineffective 7 abreast seating configuration.
So all other new designs using the same fuselage construction methods will or better could enjoy a design advantage over your design.
I get it - but no one is talking about no cargo carrying capacity - I think most assume it would be a XL LD3-45.
Yes - if you are competing with a clean sheet 6W - but how much longer and heavier would it have to get for the same capacity - it looks like 20% more length as I calculated above - that is a lot and as others have pointed out it means things like heavier longer gear - much stronger wingbox, etc.. As I showed above a Carbon 7W fuselage could be 50% heavier than an Carbon 6W A320 series per meter and your fuselage weight wouldn't change.
This shouldn't be that much either as due to the overly thick fuselage skins which would add stiffness means you can save weight elsewhere. The difference would be minimal either plus or minus.
Boeing is most likely looking at Competing with the Airbus A320 Fuselage in Aluminum in an lengthened A322 version. Yes 8W could be more efficient but that is way too big and even harder to make efficient with a given container size.
The 7W wins over the A320 as you can stretch the 7W more. Plus given that fuselage weight is such a minimal part of an aircraft - it's not really a handicap for an eventual 737 successor with smaller wing/wingbox/gear/engines. Which of course brings massive economy of scale which NMA would never get as a standalone 8W program.
The cross section really needs to be shared with NSA - and as I showed above it doesn't really seem like that much of a disadvantage to be 7W.
It may not be 7W but it almost definitely won't be 8W and it seems like it's a wash with 6W - with 7W having more growth possible.
Then assuming FSA (Future SMALL
Airplane) is the next Boeing Brazil project (which takes on short range under 3,000nm missions in an 5W design up to 180 Y seats), they then have NMA/NSA in 7W (Middle
Sized Airplane smallest 200Y at about 4,000NM and largest 320Y at 5,500NM), and the Large
passenger Aircraft is Variants on the 787 - Small, Medium and Large.
I think it would be amazing if the 777X makes it to 2030 as a Passenger Aircraft - but it will have a place as the large freighter for a long time as 747 winds down and Boeing uses the factory space for NMA.
This whole strategy fits in with what Boeing has been predicting for years - Frequency over Capacity as I can see NMA in 7W replacing a lot of 787/330 missions.