The reality is that as a (very) senior ME (Manufacturing Engineer) I get seduced by the idea of leveraging that producibility across 60-70 per month instead of 12-15, as well as (what I consider to be) the phenomenal strength of commonality between the NSA narrowbody and NMA.
I still think that quite a few don't get how significant this is.
The B737MAX9 has 3550nm range. More range the NMA would cover. I was a fan of the C-Series. I was wrong. I doubt Boeing needs a NSA. If I'm wrong again, I agree with the commonality part.
Challenge for a NSA: https://www.youtube.com/watch?v=unZeusTrDX4
But why is it significant to produce 70 instead of 12 planes a month?
I read in the early stages of solar panel assembly factories would keep three lines parallel. If line one had trouble at stage one and line two at stage three the panels could be shifted from line two to line one after stage one. Therefore the output of only one line was affected.
However A320 are assembled at three different continents. Even the assembly tools have to be bought separate for each continent.
Capital cost: Suppose development/ tools/ certification lead to long term interest cost of 500 million $/ year. If 150 planes/ year are manufactured, it's 3.3 million $/ plane. Another 5 million $/ plane or so for depreciation.
Same is true for engine maker's development cost, we have to add quite a bit more.
Yes, for capital costs it makes a huge difference if five times the planes are manufactured.
You are in manufacturing, I'm an enthusiast. You must be right. But beside capital cost I can't imagine why.
Can you please give some examples why manufacturing 70 planes/ month instead of 12/ month brings the unit cost down.
Anybody knows the cost of assembly in percentage of total cost?
Or is the cost saving with the suppliers? More like 10% or more like 30% percent difference?
Anybody knows how much suppliers have to spend for development/ tooling for a new plane type?
I think I answered my own question. Planes are mostly capital costs. Bulbs, carpets and whatever else is mass produced make only a very small percentage of total costs. All parts which are made in small numbers are costly because of development, tools, certification. In short: capital costs.
And capital costs are divided by the number of pieces sold. Is this assumption correct? Is this what you meant?
That also explains why an aircraft manufacturer can produce 6 planes/ year. The capital costs were already spent. Better to sell a few pieces at a loss than to write down all costs.
Competing with the A321XLR:
There is a limitation in this capital cost argument: Airlines don't pay the same. If an airline needs a certain type badly, I believe they are charged more.
Similary I believe an airline which may as well choose the A321XLR would be charged less for a NMA.
So capital costs are not equally distributed.
I don't understand how leasing companies fit in this argument.