Does the NTSB or the FAA have any responsibility for inspection of foreign aircraft?
Prime responsibility for the airworthiness of a plane rests with the nation where the plane is registered. Some foreign carriers fly American-registered planes that are leased from companies based in the U.S., but most fly planes registered in their own countries. The FAA does inspect foreign planes that land in U.S. airports, but inspections are infrequent and not terribly thorough.