morrisond wrote:keesje wrote:Pythagoras, CanukinUSA, thank you for your educated views, opinions above.
Back to topic, I think many of the NMA specifications, outlooks drift on one major assumption:
The 737 MAX will be just fine against A320 / A220 families this decade.
There are signs that's not a realistic assumption. Market share / backlog, order value of the 737 have been dropping.
We can play around with in service numbers, time windows, but I think the writing is on the wall on the good old 737.
It was visible already before the crashes / Covid-19.
The latest A320 vs 737 '19-'21 delivery figures / delta's are shocking. And it's not like WB's are saving Boeing.
Boeing needs to cover it's bases first and fix it's 150-220 seats up to 3000NM segment later this decade
That is the bread & butter of the global aviation market and also for Boeing. Not offering a viable A220/A320 competitor, alternative, MAX conversion option could drive Boeing South, like never before.
Meanwhile, Airbus keeps investing in NB portfolio expansion and product improvements, driven by market demand. https://groups.google.com/group/aviatio ... 0.1&view=1
As an example, I saw this A320 improvement project this week. https://www.flightglobal.com/air-transp ... 03.article A significant A320 family modification. Not required by authorities, costing a lot of time/ certification / money, reducing standardisation, reducing free cash flow. But a good long term family improvement. A very different development approach compared to policies at their biggest competitor.
I think Boeing's next airplane will be a shrunken, single aisle NMA, a 737 replacing NB. Single aisle because it seems a 225 seat, 4000NM dual aisle aircraft will always be 6-8t heavier than a 225 seat, 4000NM single aisle aircraft. There is no engineering magic that works for twin aisles only. Direct operating costs and OEW are closely related.
Shelve NMA, do a NB 10% better than the NEO's asap.
Wow - of course MAX deliveries from 19-21 were substantially worse and probably will be for sometime. Did you miss the MAX delivery shutdown and airlines not wanting to take new frames due to Covid?
Please detail for us why a tight light 2 aisle fuselage that has less skin area and less internal volume than a comparable capacity 1 aisle will be 6-8T heavier when a bare entire A320 fuselage only weighs about 5T.
Yes - the the 50% approximately by length of the fuselage cross sections that are not the nose or above the wingbox or the tail will be a bunch heavier per meter but then of course there will be about 20-25% less of those meters by length for equivalent capacity for something that is essentially the same height but with a 15" bulge on each side.
Theoretically assuming you have enough clearance for the fans the 2 aisle could possibly use shorter gear as well to obtain the same rotation angle.
The assertion that it has less skin area and 20-25%less length are not true. An equivalent capacity (number of seats but not seat width ) fuselage for twin aisle has both greater surface area, drag and weight whilst not yet taking account of additional shear loads required for floor in compression.
If I recall correctly the difference in length for a 217 seat layout was about 3m shorter for the 7abreast compared to 6abreast. This assumes identical requirements for minimum fuselage cross section required for use as well as identical taper ratios.
That’s just the fuselage...
You think that Boeing are daft enough to hamstring themselves with short gear and prevent the aircraft being stretched to where the cross section might actually make sense?
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