A Glossary of Flying Terms

A complete glossary of every aviation term would fill several textbooks. What you will find here are the terms you are most likely to encounter as you begin flying in the United Kingdom, from your first lesson through to your licence tests.

A

• AFISO — Aerodrome Flight Information Service Operator. Provides information to pilots but cannot issue instructions in the way a fully qualified Air Traffic Controller can.
• Aileron — A moveable control surface fixed near the wing tip. Moving the ailerons causes the aircraft to roll left or right, initiating a turn.
• Altimeter — An instrument that uses air pressure to indicate height. It can be set to show height above the ground (QFE), altitude above sea level (QNH), or a standardised flight level using the International Standard Atmosphere pressure of 1013.2 millibars (QNE).
• Altitude — Height above mean sea level. Not the same as height above the ground directly below you.
• Angle of Attack — The angle between the chord line of a wing and the oncoming airflow. Exceed the critical angle of attack and the wing will stall.
• AOPA — Aircraft Owners and Pilots Association. The UK branch represents general aviation interests.
• Apron — The paved area at an aerodrome where aircraft are parked, refuelled, and prepared for flight.
• Artificial Horizon — Also called an attitude indicator. A gyroscopic instrument showing the aircraft's pitch and bank relative to the horizon. Essential for flight in cloud or reduced visibility.
• ASI — Airspeed Indicator. Shows the speed of the aircraft through the air, not across the ground.
• ATC — Air Traffic Control.
• ATCO — Air Traffic Controller.
• ATPL — Airline Transport Pilot's Licence. The highest grade of pilot licence, required to act as Pilot in Command of an airliner. Requires a minimum of 1,500 hours total flight time and a CAA Class 1 medical.

C

• C of A — Certificate of Airworthiness. Issued for the aircraft, not the pilot. The aircraft must hold a valid C of A or Permit to Fly before it can legally carry passengers.
• CAA — Civil Aviation Authority. The UK's national aviation regulator, responsible for pilot licensing, aircraft airworthiness, and airspace management.
• Camber — The curvature of an aerofoil surface. Greater camber generally produces more lift at lower speeds.
• Centre of Gravity — The point through which the total weight of the aircraft acts. Keeping the centre of gravity within approved limits is a legal requirement before every flight, and becomes especially important when carrying passengers or baggage.
• CFI — Chief Flying Instructor.
• Control Column — The stick or yoke in the cockpit that controls the ailerons and elevator.
• CPL — Commercial Pilot's Licence. Allows a pilot to fly for payment. Requires a minimum of 200 hours flight time, nine theory examinations, and a CAA Class 1 medical.

D to F

• Drag — The resistance acting against an aircraft's forward motion through the air.
• Drift — The sideways displacement of an aircraft caused by a crosswind.
• Dual — Flight time logged while under the instruction of a qualified flying instructor.
• Elevator — The moveable control surface on the tailplane. Controls pitch, causing the aircraft to climb or descend.
• FI — Flying Instructor.
• Flap — A hinged surface on the trailing edge of the wing. Extending the flaps increases lift at slow speeds and steepens the approach path during landing.
• Flare — The gentle rounding-out of the descent path just before touchdown, reducing the rate of descent to allow a smooth landing.

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I to L

• IAS — Indicated Airspeed. The reading shown directly on the airspeed indicator.
• IFR — Instrument Flight Rules. The set of regulations governing flight where the pilot navigates by instruments rather than by visual reference to the ground.
• ILS — Instrument Landing System. A ground-based radio navigation system that guides aircraft onto the runway during low-visibility approaches.
• IMC — Instrument Meteorological Conditions. Weather conditions below the minima required for visual flight.
• IR — Instrument Rating. An additional qualification allowing a PPL or CPL holder to fly in IMC.
• Knot — A unit of speed equal to one nautical mile per hour. One nautical mile is 6,076 feet.
• LAPL — Light Aircraft Pilot's Licence. A UK CAA licence introduced for recreational pilots. Requires a minimum of 30 hours flight time, including 15 hours dual and 6 hours solo. Valid only within the UK and certain other countries. Requires a LAPL medical, which is less demanding than a Class 2.
• Lift — The upward force generated by airflow over the wings that keeps the aircraft in the air.

M to P

• MET — Meteorological information. Weather forecasts and reports are studied as part of the PPL theory syllabus.
• NOTAM — Notice to Airmen. Official notices containing information about changes to airspace, restrictions, or hazards relevant to flight.
• NPPL — National Private Pilot's Licence. A UK-only licence for simple single-engine aircraft and microlights, with more straightforward medical requirements than the PPL.
• Pitch — The rotation of the aircraft around its lateral axis, raising or lowering the nose.
• Pitot Tube — A forward-facing tube exposed to the airflow, forming part of the airspeed indicator system.
• Port — The left side of the aircraft when facing forward.
• PPL — Private Pilot's Licence. The standard recreational licence. Requires a minimum of 45 hours flight time, nine CAA theory examinations, a skills test, and a CAA Class 2 medical. Typical cost in the UK in 2026 ranges from around £9,000 to £15,000 depending on the school and aircraft type.
• PPR — Prior Permission Required. Some aerodromes require pilots to contact them before arrival.

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Q Codes

Q codes are standardised brevity codes used in aviation radio communications and navigation.

• QDM — Magnetic heading to steer towards a station, assuming no wind.
• QFE — Altimeter setting that causes the instrument to read zero on the ground at a specific airfield. The altimeter then shows height above that airfield.
• QNH — Altimeter setting that causes the instrument to read the airfield's elevation when on the ground. The altimeter then shows altitude above mean sea level.
• QNE — The altimeter reading obtained when the subscale is set to 1013.2 millibars. Used when flying at higher altitudes on a standard pressure setting.

R to T

• Rudder — The moveable vertical surface on the fin. Controls yaw, helping to keep the aircraft balanced in a turn and correcting for crosswind on the runway.
• Solo — Flight time logged when the pilot is the sole occupant of the aircraft, without a supervising instructor on board.
• Squawk — To transmit a four-digit code via transponder so that ATC can identify the aircraft on radar.
• Stall — Nothing to do with the engine. A stall occurs when the critical angle of attack is exceeded, causing the smooth airflow over the wing to break down. Lift drops suddenly. Stall recognition and recovery is a core part of PPL training.
• Starboard — The right side of the aircraft when facing forward.
• Tab — A small hinged surface set into a control surface. Used to trim the aircraft so that it flies in balance without continuous pressure on the controls.
• Tailplane — The fixed horizontal tail surface that provides longitudinal stability.
• TAS — True Airspeed. The actual speed of the aircraft through the surrounding air mass, corrected for altitude and temperature.
• TODA — Take-Off Distance Available. The length of the take-off run plus any clearway beyond the runway end.
• TORA — Take-Off Run Available. The declared length of runway available for the ground run during take-off.
• Track — The actual path of the aircraft across the ground. This differs from heading because of the effect of wind.
• Transponder — A radio device that responds to interrogation signals from radar, allowing ATC to identify and track the aircraft.

V

• VFR — Visual Flight Rules. The regulations that apply when flying by visual reference to the ground and horizon. Minimum visibility and cloud clearance requirements apply.
• Visibility — The distance at which objects can be clearly seen. A key factor in determining whether VFR flight is legal.

The Next Step

Now that you have read through the advice above, you might want to put it into practice. Our Pilot Training Cost Calculator lets you work out what learning to fly really costs: get a realistic UK estimate for your licence, broken down into flight hours, instruction, exams, medical and test fees, so there are no surprises. Try it now →