Aviation glossary

Plain-English meanings of the words you hear around airports and flights.

A

ADS-B: The signal an aircraft broadcasts several times a second with its identity, position, height and speed. It is how most live tracking works. Read more
Aileron: A moving panel on the back of each wing. The two move in opposite directions to roll the plane left or right. Read more
Airspeed: How fast the plane moves through the air, as opposed to over the ground.
Altitude: Height above sea level. Read more
Approach: The part of a flight where the plane lines up and descends towards the runway. Read more
Apron: The area of an airport where aircraft park, load and refuel. Also called the ramp.
ATC: Air traffic control: the people who guide aircraft in the air and on the ground.

Bank: To roll the plane so one wing is lower. This is how a plane turns. Read more

Callsign: The name of a flight spoken on the radio, such as BAW123. It can change from one flight to the next. Read more
CAVOK: A weather report phrase meaning good visibility, no low cloud and no bad weather. Read more
Clearance: Permission from air traffic control to do something, such as take off or land. Read more
Contrail: A white trail of ice crystals formed by an aircraft’s exhaust at high altitude. Read more
Crosswind: Wind blowing across the runway from the side. Read more

Decision height: The height on an instrument approach at which the pilot must see the runway or go around. Read more
Dew point: The temperature at which the air becomes full of water vapour. When it matches the air temperature, fog and mist are likely. Read more
Drag: The force that slows a plane down as it moves through the air. Read more

Elevator: A moving panel on the tail that tilts the nose up and down. Read more
ETA: Estimated time of arrival.

Final approach: The last straight part of the approach, lined up with the runway. Read more
Flap: A panel on the back of the wing that is lowered for take-off and landing to give more lift at low speed. Read more
Flight level: A height in hundreds of feet on a shared pressure scale. FL350 is about 35,000 feet. Read more

Gate: The place at the terminal where passengers board a plane.
Glideslope: The radio beam, sloping down at about 3 degrees, that guides a plane down to the runway. Read more
Go-around: Breaking off a landing, climbing away and trying again. Read more
Ground speed: How fast the plane moves over the ground. It is airspeed plus or minus the wind. Read more

Heading: The compass direction the nose is pointing. Read more
Headwind: Wind blowing against the direction the plane is going. It helps take-off and landing. Read more
Heavy: A word added to the callsigns of the biggest jets to warn others about their strong wake. Read more
Hex code: A unique code in an aircraft’s transponder, written as six letters and numbers. Read more
Holding pattern: A racetrack-shaped loop flown in the air while waiting to land. Read more

IATA code: The three-letter airport code used on tickets and bags, such as LHR. Read more
ICAO code: The four-letter airport code used by pilots and air traffic control, such as EGLL. Read more
ILS: Instrument landing system: radio beams from the runway that guide a plane down in poor visibility. Read more

Jet stream: A narrow band of very strong wind high in the sky, usually blowing west to east. Read more

Knot: One nautical mile per hour, about 1.15 mph or 1.85 km/h. Used for aircraft speed and wind speed.

Landing gear: The wheels and legs of an aircraft.
Lift: The upward force made by the wings. Read more
Localiser: The radio beam along the centre line of the runway that tells a plane if it is left or right. Read more

Mach: Speed compared with the speed of sound. Mach 1 is the speed of sound.
Mayday: The radio call for grave and immediate danger. Read more
METAR: A coded weather report for an airport, issued about every 30 minutes. Read more

Pan-pan: The radio call for an urgent problem that is not life-threatening yet. Read more
Pitch: The nose going up or down. Read more
Push-back: When a tug pushes the aircraft backwards away from the gate.

QNH: The local air pressure, adjusted to sea level, that pilots set on their altimeter. It is the Q number in a METAR. Read more

Registration: The identity painted on an aircraft, like a car’s number plate, for example G-EUUU. Read more
Roll: One wing dipping while the other rises. Read more
Rotate: To raise the nose at take-off so the plane lifts off the runway. Read more
Rudder: The moving panel on the tail fin that swings the nose left or right. Read more
Runway: The strip where aircraft take off and land. Its number is its compass heading divided by ten. Read more

Squawk: The four-digit code set on the transponder so air traffic control can identify the aircraft. Read more
Stall: A sudden loss of lift when the wing is tilted too far for the air to follow it. Read more
Stand: A parking place for an aircraft.

Tailwind: Wind blowing from behind the plane. Airports avoid using it for take-off and landing. Read more
Take-off: The part of the flight from the start of the runway run until the plane is climbing.
Taxiway: A path that connects the runways to the gates and parking stands.
Thrust: The forward push made by the engines. Read more
Touchdown: The moment the wheels touch the runway.
Transponder: The radio unit in an aircraft that sends out its squawk code and other data. Read more

V1: The speed up to which a take-off can still be stopped. After V1 the plane carries on.

Wake turbulence: Swirling air left behind by an aircraft, strongest behind large, heavy ones. Read more
Waypoint: A named point in the sky that routes are built from.
Wingspan: The distance from one wingtip to the other. Read more

Zulu: Another name for UTC, the time used by pilots worldwide. A Zulu time ends in Z. Read more