Aviation Glossaries

A
Air Route Traffic Control Center (ARTCC) or Center (USA)
A facility established to provide air traffic control service to aircraft operating on IFR flight plans within controlled airspace and principally during the en route phase of flight. When equipment capabilities and controller workload permit, certain advisory/assistance services may be provided to VFR aircraft

Air Traffic Control (ATC)
A service operated by the appropriate authority to promote the safe, orderly, and expeditious flow of air traffic

Automated Terminal Information Service (ATIS)
The continuous broadcast of recorded noncontrol information in selected terminal areas. Its purpose is to improve controller effectiveness and to relieve frequency congestion by automating the repetitive transmission of essential but routine information; ex. "Los Angeles information Alfa. One three zero zero Zulu. Weather measured ceiling two thousand overcast, visibility three, haze, smoke, temperature seven one, dew point five seven, wind two five zero at five, altimeter two niner niner six. ILS Runway Two Five Left approach in use, Runway Two Five Right closed, advise you have Alfa"

Class G Airspace (Uncontrolled Airspace)
The airspace not designated as Class A, B, C, D or E

Commuter
An air carrier operator operating under 14 CFR 135 that carries passengers on at least five round trips per week on at least one route between two or more points according to its published flight schedules that specify the times, day of the week, and places between which these flights are performed. The aircraft that a commuter operates has 30 or fewer passenger seats and a payload capability of 7,500 pounds or less

Controlled Airspace
An airspace of defined dimensions within which air traffic control service is provided to IFR flights and to VFR flights in accordance with the airspace classification. Controlled airspace is a generic term that covers Class A, Class B, Class C, Class D, and Class E airspace. Controlled airspace is also that airspace within which all aircraft operators are subject to certain pilot qualifications, operating rules, and equipment requirements in FAR Part 91 (for specific operating requirements, please refer to FAR Part 91). For IFR operations in any class of controlled airspace, a pilot must file an IFR flight plan and receive an appropriate ATC clearance. Each Class B, Class C, and Class D airspace area designated for an airport contains at least one primary airport around which the airspace is designated (for specific designations and descriptions of the airspace classes, please refer to FAR Part 71.
Controlled airspace in the United States is designated as follows:

1. Class A (formerly PCA -Positive Control Area)
generally, that airspace from 18,000 feet mean sea level (MSL) up to and including flight level (FL) 600 (60,000 feet 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.

2. Class B (formerly TCA Terminal Control Area)
Generally, that airspace from the surface to 10,000 feet mean sea level (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."

^ back to top

3. Class C (formerly ARSA Airport Radar Service Area)
Generally, that airspace from the surface to 4,000 feet above the airport elevation (charted in mean sea level (MSL)) 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 feet to 4,000 feet 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.

4. Class D (formerly ATA Airport Traffic Area and CZ Control Zone)
Generally, that airspace from the surface to 2,500 feet above the airport elevation (charted in mean sea level (MSL)) 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 Class 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.

5. Class E (formerly General Controlled Airspace)
Generally, if the airspace is not Class A, Class B, Class C, or Class D, and it 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 feet AGL used to transition to/from the terminal or enroute environment, enroute domestic, and offshore airspace areas designated below 18,000 feet mean sea level (MSL). Unless designated at a lower altitude, Class E airspace begins at 14,500 feet mean sea level (MSL) over the United States, 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 feet mean sea level (MSL), and the airspace above flight level (FL) 600.

^ back to top

General Aviation
That portion of civil aviation which encompasses all facets of aviation except air carriers holding a certificate of public convenience and necessity from the Civil Aeronautics Board and large aircraft commercial operators

Gyroplane
A rotorcraft whose rotors are not engine-driven, except for initial starting, but are made to rotate by action of the air when the rotorcraft is moving; and whose means of propulsion, consisting usually of conventional propellers, is independent of the rotor system

I
IFR Aircraft / IFR Flight
An aircraft conducting flight in accordance with instrument flight rules

Instrument Flight Rule (IFR)
A set of rules governing the conduct of flight under instrument meteorological conditions

Instrument Meteorological Conditions (IMC)
Meteorological conditions expressed in terms of visibility, distance from clouds, and ceiling less than minima specified for visual meteorological conditions

Instrument Operations
Arrivals or departures of an aircraft in accordance with an IFR flight plan or special VFR procedures or an operation where IFR separation between aircraft is provided by a terminal control facility. There are three kinds of instrument operations:
1. Primary Instrument Operations: arrivals and departures at the primary airport which is normally the airport at which the approach control facility is located
2. Secondary Instrument Operations: arrivals and departures at airports other than the primary airport
3. Overflights: operations in which an aircraft transits the area without intent to land

^ back to top

M - suggestions?

^ back to top

Q - suggestions?

^ back to top

U
Ultralight Vehicle
An aeronautical vehicle operated for sport or recreational purposes which does not require FAA registration, an airworthiness certificate, nor pilot certification. They are primarily single occupant vehicles, although some two place vehicles are authorized for training purposes. Operation of an ultralight vehicle in certain airspace requires authorization from ATC

^ back to top