As you all know, the Aircraft Manufacturing Preproduction starts not with developing the parts manufacturing technologies, but in contrary, from technological processes of final assembly stage.
📌 Means, at the first we need to decide HOW exactly we are going to assemble Aircraft as a whole, next - what will be our Agregate asembling looks like, than Unit assembling - and only after all these decisions are made we may start preparing manufacturing of parts.
So, we start with assembling ...