26 U.S.C. § 4262: Definition of taxable transportation

transportation by air which begins in the United States or in the 225–mile zone and ends in the United States or in the 225–mile zone; and in the case of transportation by air other than transportation described in paragraph (1), that portion of such transportation which is directly or indirectly from one port or station in the United States to another port or station in the United States, but only if such portion is not a part of uninterrupted international air transportation (within the meaning of subsection (c)(3)). such portion is outside the United States; between (i) a point where the route of the transportation leaves or enters the continental United States, or (ii) a port or station in the 225-mile zone, and a port or station in the 225-mile zone; begins at either (i) the point where the route of the transportation leaves the United States, or (ii) a port or station in the 225-mile zone, and ends at either (i) the point where the route of the transportation enters the United States, or (ii) a port or station in the 225-mile zone; and a direct line from the point (or the port or station) specified in paragraph (3)(A), to the point (or the port or station) specified in paragraph (3)(B), passes through or over a point which is not within 225 miles of the United States. The term “continental United States” means the District of Columbia and the States other than Alaska and Hawaii. The term “225-mile zone” means that portion of Canada and Mexico which is not more than 225 miles from the nearest point in the continental United States. the scheduled interval between (i) the beginning or end of the portion of such transportation which is directly or indirectly from one port or station in the United States to another port or station in the United States and (ii) the end or beginning of the other portion of such transportation is not more than 12 hours, and the scheduled interval between the beginning or end and the end or beginning of any two segments of the portion of such transportation referred to in subparagraph (A)(i) is not more than 12 hours. For purposes of this part, the term “transportation” includes layover or waiting time and movement of the aircraft in deadhead service. the Secretary shall publish a notice of such determination in the Federal Register, and effective with respect to transportation beginning after the date specified in such notice, to the extent provided in the agreement, the term “225-mile zone” shall not include part or all of the country with respect to which such determination is made. the Secretary shall publish a notice of such determination in the Federal Register, and subparagraph (B) of paragraph (1) shall cease to apply with respect to transportation beginning after the date specified in such notice. setting forth that portion of such country which is not to be treated as within the 225-mile zone, and providing that the tax imposed by such country on transportation described in subparagraph (A) will be at a level which the Secretary of the Treasury determines to be appropriate. No notice may be published under paragraph (1)(A) with respect to any qualified agreement before the date 90 days after the date on which a copy of such agreement was furnished to the Committee on Ways and Means of the House of Representatives and the Committee on Finance of the Senate.