| Absolute altitude |
| The measurable height of an aircraft above the actual terrain. |
|
| top |
| Absolute ceiling |
| The maximum altitude above sea level at which an aircraft can maintain level flight under Standard Air conditions. |
|
| top |
| Accelerated stall |
| Any stall made to occur at other than 1g. |
|
| top |
| Aileron |
| The movable areas of a wing form that control or affect the roll of an aircraft by working opposite one another — up-aileron on the right wing and down-aileron on the left wing. French: aileron small wing, diminutive of aile, from Latin: ala, wing. The word "aisle" also derives from the same root. |
|
| top |
| Air taxi |
| An aircraft operator who conducts operations for hire or compensation in accordance with FAR Part 135 in an aircraft with 30 or fewer passenger seats and a payload capacity of 7,500# or less. An air taxi operates on an on demand basis and does not meet the "flight scheduled" qualifications of a commuter. |
|
| top |
| Airport Traffic Control Tower (Atct) |
| A terminal facility that uses air/ground communications, visual signaling, and other devices to provide ATC services to aircraft operating in the vicinity of an airport or on the movement area. Authorizes aircraft to land or takeoff at the airport controlled by the tower or to transit the Class D airspace area regardless of flight plan or weather conditions (IFR or VFR). A tower may also provide approach control services (radar or non-radar). |
|
| top |
| Automatic Terminal Information Service (Atis) |
| Continuous broadcast of recorded non-control information in selected terminal areas, to improve controller effectiveness and to relieve frequency congestion by automating repetitive transmissions of essential but routine information. |
|
| top |
| CERTIFICATED Airport |
| an airport operating under FAR Part 139. The FAA issues airport operating certificates to all airports serving scheduled or unscheduled air carrier aircraft designed for more than 30 passenger seats. Certificated airports must meet minimum safety standards in accordance with FAR Part 139. |
|
| top |
| Class A |
| (formerly PCA - Positive Control Area) generally, that airspace from 18,000' mean sea level (MSL) up to and including flight level (FL) 600 (60,000' pressure altitude), including the airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States and Alaska. Unless otherwise authorized, all persons must operate their aircraft under IFR. |
|
| top |
| Class B |
| (formerly TCA - Terminal Control Area) Generally, that airspace from the surface to 10,000' MSL surrounding the nation's busiest airports in terms of airport operations or passenger enplanements. The configuration of each Class B airspace area is individually tailored and consists of a surface area and two or more layers (some Class B airspace areas resemble upside-down wedding cakes), and is designed to contain all published instrument procedures once an aircraft enters the airspace. An ATC clearance is required for all aircraft to operate in the area, and all aircraft that are so cleared receive separation services within the airspace. The cloud clearance requirement for VFR operations is "clear of clouds." |
|
| top |
| Class C |
| (formerly ARSA - Airport Radar Service Area) Generally, that airspace from the surface to 4,000' MSL above the airport elevation surrounding those airports that have an operational control tower, are serviced by a radar approach control, and that have a certain number of IFR operations or passenger enplanements. Although the configuration of each Class C area is individually tailored, the airspace usually consists of a surface area with a 5 nautical mile (nm) radius, an outer circle with a 10 nm radius that extends from 1,200' to 4,000' above the airport elevation and an outer area. Each person must establish two-way radio communications with the ATC facility providing air traffic services prior to entering the airspace and thereafter maintain those communications while within the airspace. VFR aircraft are only separated from IFR aircraft within the airspace. |
|
| top |
| Class D |
| (formerly ATA - Airport Traffic Area and CZ - Control Zone) Generally, that airspace from the surface to 2,500' MSL above the airport elevation surrounding those airports that have an operational control tower. The configuration of each Class D airspace area is individually tailored and when instrument procedures are published, the airspace will normally be designed to contain the procedures. Arrival extensions for instrument approach procedures may be Class D or E airspace. Unless otherwise authorized, each person must establish two-way radio communications with the ATC facility providing air traffic services prior to entering the airspace and thereafter maintain those communications while in the airspace. No separation services are provided to VFR aircraft. |
|
| top |
| Class E |
| (formerly General Controlled Airspace) Generally, if the airspace is not Class A, B, C, or D, and is controlled airspace, it is Class E airspace. Class E airspace extends upward from either the surface or a designated altitude to the overlying or adjacent controlled airspace. When designated as a surface area, the airspace will be configured to contain all instrument procedures. Also in this class are Federal airways, airspace beginning at either 700' or 1,200' AGL used to transition to/from the terminal or enroute environment, enroute domestic, and offshore airspace areas designated below 18,000' MSL. Unless designated at a lower altitude, Class E airspace begins at 14,500' MSL over the USA, including that airspace overlying the waters within 12 nautical miles of the coast of the 48 contiguous States and Alaska, up to, but not including 18,000' MSL, and the airspace above Flight Level 600. |
|
| top |
| Common Traffic Advisory Frequency (Ctaf) |
| A frequency designed for the purpose of carrying out airport advisory practices while operating to or from an airport without an operating control tower. The CTAF may be a UNICOM, Multicom, FSS, or tower frequency and is identified in appropriate aeronautical publications. |
|
| top |
| En Route Air Traffic Control Services |
| Air traffic control services provided aircraft on IFR flight plans, generally by centers, when these aircraft are operating between departure and destination terminal areas. When equipment, capabilities, and controller workload permit, certain advisory/assistance services may be provided to VFR aircraft. |
|
| top |
| FBO |
| Fixed-Base Operator, a commercial operator supplying fuel, maintenance, flight training, and other services at an airport. |
|
| top |
| Flight Plan |
| Specified information relating to the intended flight of an aircraft that is filed orally or in writing with an FSS or an ATC facility. |
|
| top |
| Flight Service Station (Fss) |
| Air traffic facilities which provide pilot briefing, enroute communications and VFR search and rescue services, assist lost aircraft and aircraft in emergency situations, relay ATC clearances, originate Notices to Airmen, broadcast aviation weather and NAS information, receive and process IFR flight plans, and monitor navaids. In addition, at selected locations, fsss provide Enroute Flight Advisory Service (Flight Watch), take weather observations, issue airport advisories, and advise Customs and Immigration of transborder flights. |
|
| top |
| MSL |
| Mean Sea Level. The average height of the surface of the sea for all stages of tide; used as a reference for elevations, and differentiated from AGL. |
|
| top |
| National Airspace System (Nas) |
| The common network of US airspace; air navigation facilities, equipment and services, airports or landing areas; aeronautical charts, information and services; rules, regulations and procedures, technical information, and human resources and material. Included are system components shared jointly with the military. |
|
| top |
