Editorial Note on Part 139
Editorial Note: Nomenclature changes to part 139 appear at 69 FR 24069, May 3, 2004.

§ 139.5 Definitions. The following are definitions of terms used in this part: *Accountable executive* means an individual designated by the certificate holder to act on its behalf for the implementation and maintenance of the Airport Safety Management System. The accountable executive has control of the certificate holder's human and financial resources for operations conducted under an Airport Operating Certificate. The accountable executive has ultimate responsibility to the FAA, on behalf of the certificate holder, for the safety performance of operations conducted under the certificate holder's Airport Operating Certificate.
*AFFF* means aqueous film forming foam agent.
*Air carrier aircraft* means an aircraft that is being operated by an air carrier and is categorized as either a large air carrier aircraft if designed for at least 31 passenger seats or a small air carrier aircraft if designed for more than 9 passenger seats but less than 31 passenger seats, as determined by the aircraft type certificate issued by a competent civil aviation authority.
*Air carrier operation* means the takeoff or landing of an air carrier aircraft and includes the period of time from 15 minutes before until 15 minutes after the takeoff or landing.
*Airport* means an area of land or other hard surface, excluding water, that is used or intended to be used for the landing and takeoff of aircraft, including any buildings and facilities.
*Airport Operating Certificate* means a certificate, issued under this part, for operation of a Class I, II, III, or IV airport.
*Airport Safety Management System (SMS)* means an integrated collection of processes and procedures that ensures a formalized and proactive approach to system safety through risk management.
*Average daily departures* means the average number of scheduled departures per day of air carrier aircraft computed on the basis of the busiest 3 consecutive calendar months of the immediately preceding 12 consecutive calendar months. However, if the average daily departures are expected to increase, then “average daily departures” may be determined by planned rather than current activity, in a manner authorized by the Administrator.
*Certificate holder* means the holder of an Airport Operating Certificate issued under this part.
*Class I airport* means an airport certificated to serve scheduled operations of large air carrier aircraft that can also serve unscheduled passenger operations of large air carrier aircraft and/or scheduled operations of small air carrier aircraft.
*Class II airport* means an airport certificated to serve scheduled operations of small air carrier aircraft and the unscheduled passenger operations of large air carrier aircraft. A Class II airport cannot serve scheduled large air carrier aircraft.
*Class III airport* means an airport certificated to serve scheduled operations of small air carrier aircraft. A Class III airport cannot serve scheduled or unscheduled large air carrier aircraft.
*Class IV airport* means an airport certificated to serve unscheduled passenger operations of large air carrier aircraft. A Class IV airport cannot serve scheduled large or small air carrier aircraft.
*Clean agent* means an electrically nonconducting volatile or gaseous fire extinguishing agent that does not leave a residue upon evaporation and has been shown to provide extinguishing action equivalent to halon 1211 under test protocols of FAA Technical Report DOT/FAA/AR-95/87.
*Hazard* means a condition that could foreseeably cause or contribute to: ( 1 ) injury, illness, death, damage to or loss of system, equipment, or property, or
( 2 ) an aircraft accident as defined in 49 CFR 830.2.
*Heliport* means an airport, or an area of an airport, used or intended to be used for the landing and takeoff of helicopters.
*Index* means the type of aircraft rescue and firefighting equipment and quantity of fire extinguishing agent that the certificate holder must provide in accordance with § 139.315.
*Joint-use airport* means an airport owned by the Department of Defense, at which both military and civilian aircraft make shared use of the airfield.
*Movement area* means the runways, taxiways, and other areas of an airport that are used for taxiing, takeoff, and landing of aircraft, exclusive of loading ramps and aircraft parking areas.
*Non-movement area* means the area, other than that described as the movement area, used for the loading, unloading, parking, and movement of aircraft on the airside of the airport (including ramps, apron areas, and on-airport fuel farms).
*Regional Airports Division Manager* means the airports division manager for the FAA region in which the airport is located.
*Risk* means the composite of predicted severity and likelihood of the potential effect of a hazard.
*Risk analysis* means the process whereby a hazard is characterized for its likelihood and the severity of its effect or harm. Risk analysis can be either a quantitative or qualitative analysis; however, the inability to quantify or the lack of historical data on a particular hazard does not preclude the need for analysis.
*Risk mitigation* means any action taken to reduce the risk of a hazard's effect.
*Safety area* means a defined area comprised of either a runway or taxiway and the surrounding surfaces that is prepared or suitable for reducing the risk of damage to aircraft in the event of an undershoot, overshoot, or excursion from a runway or the unintentional departure from a taxiway.
*Safety assurance* means processes within the SMS that function systematically to ensure the performance and effectiveness of risk controls or mitigations and that the organization meets or exceeds its safety objectives through the collection, analysis, and assessment of information.
*Safety policy* means the certificate holder's documented commitment to safety, which defines its safety objectives and the accountabilities and responsibilities of its employees in regard to safety.
*Safety promotion* means a combination of training and communication of safety information to support the implementation and operation of a SMS in an organization.
*Safety risk management* means a process within the SMS composed of describing the system, identifying the hazards, and analyzing, assessing, and controlling or mitigating the risk.
*Scheduled operation* means any common carriage passenger-carrying operation for compensation or hire conducted by an air carrier for which the air carrier or its representatives offers in advance the departure location, departure time, and arrival location. It does not include any operation that is conducted as a supplemental operation under 14 CFR part 121 or public charter operations under 14 CFR part 380.
*Shared-use airport* means a U.S. Government-owned airport that is co-located with an airport specified under § 139.1(a) and at which portions of the movement areas and safety areas are shared by both parties.
*Unscheduled operation* means any common carriage passenger-carrying operation for compensation or hire, using aircraft designed for at least 31 passenger seats, conducted by an air carrier for which the departure time, departure location, and arrival location are specifically negotiated with the customer or the customer's representative. It includes any passenger-carrying supplemental operation conducted under 14 CFR part 121 and any passenger-carrying public charter operation conducted under 14 CFR part 380.
*Wildlife hazard* means a potential for a damaging aircraft collision with wildlife on or near an airport. As used in this part, “wildlife” includes feral animals and domestic animals out of the control of their owners.
Note:
*Special Statutory Requirement To Operate to or From a Part 139 Airport.* Each air carrier that provides—in an aircraft designed for more than 9 passenger seats—regularly scheduled charter air transportation for which the public is provided in advance a schedule containing the departure location, departure time, and arrival location of the flight must operate to and from an airport certificated under part 139 of this chapter in accordance with 49 U.S.C. 41104(b). That statutory provision contains stand-alone requirements for such air carriers and special exceptions for operations in Alaska and outside the United States. Certain operations by air carriers that conduct public charter operations under 14 CFR part 380 are covered by the statutory requirements to operate to and from part 139 airports. See 49 U.S.C. 41104(b).
[Doc. No. FAA-2000-7479, 69 FR 6424, Feb. 10, 2004, as amended by Amdt. 139-27, 78 FR 3316, Jan. 16, 2013; Docket No. FAA-2010-0997;Amdt. No. 139-28, 88 FR 11671, Feb. 23, 2023]