Okay, I'm a machinist for an airline. I've known of 3D printing for model parts since the 80's. To me the issue is, what materials can you print with and how well do they bond. The 787 Dreamliner is composite. I said probably 5 months ago, "imagine a huge 3D printer large enough to make a 787?"
I'm on board!
Can't see them ever being able to, exactly replicate every material on an original.
Ralphy