5-6k airframes out of the air immediately, 15k+ if it extends to US made planes with Canadian engines. Not happening.
What a president! International relations genius, master of all things economics, knowledgeable in the arts (Trump-Kennedy Center!), grandmaster of military strategy, and now revealed as an airworthiness expert.
Is there anything this man can't do? Could we be more lucky in having him as our president? No, and no!
If he is also removing certification from existing planes, then good luck to US regional airliners and their customers.