Originally posted by AO283: "As a designer/manufacturer, WHATEVER you run into, you don't want to 'break the Type Certificate'. Breaking the TC is not only very costly but will also cause substantial delay. "
I would think that virtually ANY change to an approved type design requires an amendment to the Type Certificate. See the B737 Type Certification Data Sheet (TCDS) on the FAA website:
TCDS A16WE Rev 64 Boeing Company, The