Airport Classification

Airport Classification

For the purpose of stipulating geometric design standards for the various types of airports and the functions which they serve, letter and numerical codes and other descriptors have been adopted to classify airports.

For design purposes, airports are classified based on the aircraft they accommodate. While at any airport, a wide variety of aircraft, from small general aviation piston-engine aircraft to heavy air transport aircraft, will use the airfield, airports are designed based on a series of ?critical? or ?design? aircraft. T the fleet using the airport as those most critical to airfield design. The

FAA defines the term critical aircraft as the aircraft most demanding on airport design that operates at least 500 annual itinerant operations at a given airport. In many cases, more than one critical aircraft will be selected at an airport for design purposes. For example, it is often the smallest aircraft that is critical to the orientation of runways, while the largest aircraft determines most of the other dimensional specifications of an airfield.

The airport reference code is a coding system used to relate the airport design criteria to the operational and physical characteristics of the aircraft intended to operate at the airport. It is based upon the aircraft approach category and the airplane design group to which the aircraft is assigned. The aircraft approach category, is determined by the aircraft approach speed, which is defined as 1.3 times the stall speed in the landing configuration of aircraft at maximum certified landing weight.

The airplane design group (ADG) is a grouping of aircraft based upon wingspan or tail height, An airplane design group for a particular aircraft is assigned based on the greater (higher Roman numeral) of that associated wi or tail height.

The airport reference code is a two designator code referring to the aircraft approach category and the airplane design group for which the airport has been designed. For example, an airport reference code of B-III is an airport designed to accommodate aircraft with approach speeds from 91 to less than 121 kn (aircraft approach category B) with wingspans from 79 to less than 118 ft or tail heights from 30 to less than 45 ft (airplane design group III). The FAA publishes a list of the airport reference codes for various aircraft in Advisory Circular 150/5300-13 ?Airport Design. As an example, an airport designed to accommodate the Boeing 767-200 which has an approach speed of 130 kn (aircraft approach category C) and a wingspan of 156 ft 1 in (airplane design group IV) would be classified with an airport reference code C-IV.

The ICAO uses a two-element code, the aerodrome reference code, to classify the geometric design standards at an airport . The code elements consist of a numeric and alphabetic designator. The aerodrome code numbers 1 through 4 classify the length of the runway available, the reference field length, which includes the runway length and, if present, the stopway and clearway. The reference field length is the approximate required runway takeoff length converted to an equivalent length at mean sea level, 15 o C, and zero percent gradient. The aerodrome code letters A through E classify the wingspan and outer main gear wheel span for the aircraft for which the airport has been designed.