GCAA ATC Licence key terms

The General Civil Aviation Authority is the UAE national regulator for civil aviation; it sets safety rules, oversees licensed personnel and approves air traffic services providers.

The body of rules issued by the GCAA setting out legally binding requirements for aviation in the UAE, covering operations, licensing, airspace and air traffic services.

An authorisation entered on a controller's licence permitting the holder to provide one specific type of service, such as aerodrome, approach or area control, usually with further unit endorsements.

The spacing between aircraft measured as a difference in height, achieved by assigning them different altitudes or flight levels so that they do not conflict.

Keeping aircraft apart by placing them on different tracks, routes, radials or geographic areas, so that their ground positions are separated horizontally.

Spacing aircraft that follow the same track so that a specified time or distance gap is kept between them, often checked as each aircraft passes a reporting point.

Horizontal spacing between aircraft whose positions are seen on a surveillance display, applied as a minimum distance and requiring positive identification of both aircraft.

Reduced Vertical Separation Minimum: the arrangement allowing 1,000 feet between aircraft at specified upper levels, used only in designated airspace by aircraft with approved altimetry and equipment.

Extra spacing applied to an aircraft following a heavier one, because the leader leaves swirling vortices that can upset or roll the follower, especially at low speed.

A published path over the ground for aircraft to follow, identified by a designator and defined by its direction, width and any level restrictions.

An airspace of defined size in which flight information service and alerting service are provided, and within which a named ATS unit accepts responsibility.

A volume of airspace extending upward from a published lower limit in which air traffic control service is given to controlled flights, typically enclosing airways and terminal areas.

An authorisation for an aircraft to move or proceed under conditions stated by a controller, which the pilot must read back and follow unless safety requires otherwise.

The agreed moment and procedure when responsibility for providing control of an aircraft passes from one controller, sector or unit to another.

A written document between two ATS units or sectors describing how they coordinate traffic, where control changes hands and what separation is applied at the boundary.

The tower service covering aircraft on the manoeuvring area and flying in the aerodrome vicinity, issuing clearances to taxi, take off and land, and passing traffic information.

The tower function that manages aircraft and vehicles on taxiways and other parts of the manoeuvring area except the runway, issuing taxi instructions and keeping routes free of conflict.

Any incorrect presence of an aircraft, vehicle or person on a runway or its protected area, creating a collision risk with aircraft landing, taking off or moving there.

Pre-set aerodrome measures applied when visibility or cloud base drops below stated values, protecting instrument approaches and surface movement by restricting access and traffic flow.

A routine coded observation of weather at an aerodrome, issued at fixed times and reporting wind, visibility, cloud, temperature, pressure and significant phenomena.

A coded forecast for one aerodrome covering a stated period, giving expected wind, visibility, cloud and significant weather along with the timing of changes.

A warning message about weather that may endanger aircraft over a specified area, such as severe turbulence, icing, thunderstorms, dust storms or volcanic ash.

Runway Visual Range is the distance a pilot should be able to see along the runway, measured instrumentally and used to judge whether take-off or landing is allowed.

A surface of constant pressure shown on the altimeter when it is set to the standard datum, expressed in hundreds of feet and used above the transition altitude.

The published altitude above an aerodrome or area at which aircraft switch the altimeter to standard pressure and continue the climb using flight levels instead of altitudes.

Area navigation, a method allowing aircraft to fly a chosen path between any points using onboard computing rather than tracking directly to or from ground beacons.

Instrument Landing System: ground equipment that gives an approaching aircraft lateral and vertical guidance, allowing it to land safely in poor visibility.

Aeronautical Information Publication: the national document holding permanent information needed for air navigation, such as aerodromes, routes, airspace and operating procedures.

A notice issued to warn pilots of temporary or short-notice changes and hazards, for example a closed runway, an unserviceable aid or a crane near a flight path.

A system for issuing significant aeronautical changes on fixed, internationally agreed effective dates, so that charts and databases can be updated before the change applies.

Secondary Surveillance Radar sends interrogations to an aircraft transponder and receives coded replies, giving the controller identity and usually altitude information.

A system in which aircraft automatically broadcast position and other data derived from onboard systems, allowing ground stations and other aircraft to see them.

A pilot's repetition of the important parts of a clearance or instruction, so the controller can check that the message was received correctly.

A controller's up-to-date mental picture of the traffic, weather and airspace under their responsibility, including what is likely to happen next.

Using knowledge of human behaviour and teamwork to get the best from people, equipment and information in an operational unit, especially under pressure.

An exchange in which the receiver repeats the message back so the sender can confirm it was heard correctly and meant as intended.

A formal framework an organisation uses to manage safety, covering hazard identification, risk assessment, reporting, investigation and monitoring of safety performance.

A way of working in which people report errors honestly without fear of punishment, while reckless or deliberate breaches of rules are still treated seriously.

A condition in which an aircraft is threatened by serious or immediate danger and needs urgent help, declared by the spoken word MAYDAY.

A prepared set of arrangements describing what an ATS unit will do if equipment fails, a facility is lost or the service must be provided from elsewhere.