[jbay808]

This is so, so not the case! If anything it's the opposite.

First of all, nobody is CNC machining airplanes from billet. They're sheet metal structures. But that aside...

For handmade structures with little tooling, the difference is less because it takes only a bit more training and about the same amount of time to make a bunch of unique parts as to make a bunch of identical parts. The economies of scale are there, but less so.

But even for CNC parts, extra shapes means extra CNC programming time (expensive but amortizes over the number of pieces made, so n unique parts costs n times as much to setup and amortizes n times less). It means more inspection gauges. More tooling. Significantly more inventory costs.

Design a machine from a single modular piece, and all else equal it will be much cheaper than one made from a bunch of unique parts.

[calaphos]

Modern aircraft, as in 787 and a350 are mostly carbon composite structures by now. I image that would be even more the case for a blended wing body Design