[nothercastle]

You can’t fly it to prove safety to FAA or EASA. It needs a ton of build and test data to show it’s been designed and built correctly. Also those agencies don’t allow use of stolen data so you have to replicate all the material allowable testing to get credit for it. Airbus had to do that when they started up. They stole all of the design data from the us and then had to slowly reconstruct it to launder it into an acceptable form. The Chinese are doing the same thing and will need to complete the process to get FAA and EASA approval for their models. The process is sort of like doing your homework when you have the answer key, it’s simpler than without one but still quite time consuming.