Aircraft Subcategory: The most detailed level of classification used in this standard for aircraft
and aviation. For use in performing the specified analyses, the aircraft categories are divided
into subcategories that consist of aircraft types having similar physical characteristics and
distributions of crash parameters.
Aircraft Type: As defined by the FAA and used in this standard, a specific make and basic
model of aircraft.
Airport: As defined by the FAA, an area of land or water that is used or intended to be used for
the landing and takeoff of aircraft. This includes any buildings or facilities on the area.
Airport Operation: As defined by the FAA, the number of arrivals and departures from the
airport at which the airport traffic control tower is located. There are two types of airport
operations, local and itinerant. Local operations are those performed by aircraft that (1) operate
in the local traffic pattern or within sight of the airport; (2) depart for or arrive from flight in
practice areas located within a 37-km (20-mile [assuming nautical miles]) radius of the airport; or
(3) execute simulated instrument approaches or low passes at the airport. All aircraft operations
other than local operations are itinerant operations.
ARTCC: Air Route Traffic Control Center.
Barrier: A building, structural component, or object (e.g., equipment) that has the potential to
prevent a missile from impacting a target, or to mitigate the effects of a missile impacting a
Certificated Air Carrier: As defined by the FAA, an air carrier holding a Certificate of Public
Convenience and Necessity issued by the U.S. Department of Transportation (DOT) to conduct
scheduled services interstate. Nonscheduled or charter operations may also be conducted by
these carriers. Certificated air carriers operate large aircraft (30 seats or more or a maximum
payload of 3401 kg [7,500 lb] or more) in accordance with 14 CFR 121.
Commercial Aviation: For the purpose of this standard, any aircraft activity performed under
14 CFR Parts 121, 125, 127, and 135.