Section 139.1 - Applicability(a) This part prescribes rules governing the certification and operation of airports in any State of the United States, the District of Columbia, or any territory or possession of the United States serving any-(1) Scheduled passenger-carrying operations of an air carrier operating aircraft configured for more than 9 passenger seats, as determined by the regulations under which the operation is conducted or the aircraft type certificate issued by a competent civil aviation authority; and(2) Unscheduled passenger-carrying operations of an air carrier operating aircraft configured for at least 31 passenger seats, as determined by the regulations under which the operation is conducted or the aircraft type certificate issued by a competent civil aviation authority.(b) This part applies to those portions of a joint-use or shared-use airport that are within the authority of a person serving passenger-carrying operations defined in paragraphs (a)(1) and (a)(2) of this section.(c) This part does not apply to-(1) Airports serving scheduled air carrier operations only by reason of being designated as an alternate airport;(2) Airports operated by the United States;(3) Airports located in the State of Alaska that only serve scheduled operations of small air carrier aircraft and do not serve scheduled or unscheduled operations of large air carrier aircraft;(4) Airports located in the State of Alaska during periods of time when not serving operations of large air carrier aircraft; orDoc. No. FAA-2000-7479, 69 FR 6424, Feb. 10, 2004, as amended by Amdt. 139-27, 78 FR 3316, Jan. 16, 2013