Abeam

An aircraft is "abeam" a fix, point, or object when that fix, point, or object is approximately 90 degrees to the right or left of the aircraft track. Abeam indicates a general position rather than a precise point.

Absolute altitude

Absolute altitude is the height of the aircraft above the terrain over which it is flying.

Air traffic control

Air traffic control (ATC) involves humans (typically on the ground) who communicate with aircraft to help maintain separation — that is, they ensure that aircraft are far enough apart horizontally or vertically that there is no risk of collision. Controllers may co-ordinate position reports provided by pilots, or in high traffic areas (such as the United States) they may use RADAR to see aircraft positions.

Airspeed indicator

The airspeed indicator or airspeed gauge is an instrument used in an aircraft to display the craft's airspeed, typically in knots, to the pilot.

Altimeter

An altimeter is an active instrument used to measure the altitude of an object above a fixed level. The traditional altimeter found in most aircraft works by measuring the air pressure from a static port. Air pressure decreases with an increase of altitude.

Altitude

Altitude is the elevation of an object from a known level. In the United States and the UK aviation altitude is usually measured in feet. Everywhere else in the world the altitude is measured in metres. In aviation, the term altitude can have several meanings. It is a fundamental tenet of flight safety that both parties exchanging information concerning this topic are absolutely clear which definition is being used.

Approach slope

An approach slope is the path that an airplane follows on its final approach to land on a runway. It takes its name from the fact that this path is ideally a gentle downward slope. A commonly used approach slope is 3° from the horizontal. However certain airports have steeper approach paths based on the topography and buildings.

Approach speed

The recommended speed contained in aircraft manuals used by pilots when making an approach to landing. This speed will vary for different segments of an approach as well as for aircraft weight and configuration.

Automatic Terminal Information Service

Automatic Terminal Information Service, or ATIS, is a continuous broadcast of recorded noncontrol information in busier terminal (i.e. airport) areas. ATIS broadcasts contain essential information, such as weather information, which runways are active, available approaches, and any other information required by the pilots, such as NOTAMs. Pilots usually listen to an available ATIS broadcast before contacting the local control tower, in order to reduce the controllers' workload and relieve frequency congestion.

The recording is updated when there is a significant change in the information, like a change in the active runway. It is given a letter designation (e.g. bravo), from the Phonetic Alphabet. The letter progresses down the alphabet and starts at Alpha each day. When contacting the control tower or ground station, a pilot will indicate he/she has "information" and the ATIS identification letter to let the controller know that the pilot is up to date with all current information.

Aviation

Aviation refers to flying using aircraft, machines designed by humans for atmospheric flight. More generally, the term also describes the activities, industries, and regulatory bodies associated with aircraft.