[hef19898]

Each commercially ised or sold aircraft has to come from a certified Desogn Organisation, has to be built by a certified Production Organisation (in most cases the same company, aerospace legallish Airbus and Boeing have a DO and a PO which arw separate entities as far as authorities are converned), needs an Type Certificate (achieved after successful flight testing and to be redone if there are configuration and design changes) and has to be maintained by a certified maintenance organisation and operated by a certified operator (continued airworthymess is a operator thing, just don't ask me any details on that, I work on the PO and touched some maintenance stuff in my life so far).

Usually, EASA and FAA cross certify, making it easier to get one if you have the other already. Fascinating stuff, aerospace certification.

[landemva]

Boeing skipped the step "to be redone if there are configuration and design changes" for the 737MAX, and smoothed over the differences with software. FAA was supportive of that rule-bending, and other countries followed along.

[hef19898]

Yes and no. They din't skip it, the FAA acceptrd and certified the new design based data Boeing provided. Boeing should have, in my opinion, completely recertified the MAX instead of treating it as just a new 737 variant.