49 U.S. Code § 47529 - Nonaddition rule
(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—
The Secretary of Transportation may provide an exemption from subsection (a) of this section to permit a person to obtain modifications to an aircraft to meet the stage 3 noise levels.
(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—
a corporation, trust, or partnership organized under the laws of the United States or a State (including the District of Columbia);