(a)General Limitations.—Except as provided in subsection (b) of this section and section 47530 of this title, a person may operate a civil subsonic turbojet aircraft with a maximum weight of more than 75,000 pounds that is imported into the United States after November 4, 1990, only if the aircraft—
complies with the stage 3 noise levels; or
(c)Aircraft Deemed Not Imported.—In this section, an aircraft is deemed not to have been imported into the United States if the aircraft—
(1) was owned on November 5, 1990, by—
an individual who is a citizen of the United States; or
enters the United States not later than 6 months after the expiration of a lease agreement (including any extension) between an owner described in clause (1) of this subsection and a foreign carrier.