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The Aviation definitions and terminology

Aviation definitions

Aviation terminology

The universal language across the Aviation terminology and definitions industry is English, but there are some aviation terms that also have their roots in other languages like French, German, and sometimes military lexicon.Aviation terminology

However, even in English, Aviation terminology can use words with a totally different meaning than those in any other context. What’s more, Aviation terminology comes in a handful of forms, such as abbreviations, acronyms, and slang.

To help you do just that, here we share our comprehensive glossary of aviation terms.

Aviation Terms

Are you thinking of joining the aviation field? Do you dream about becoming a pilot? How can this be achieved without knowing the aviation terms used all over the world?

These are the Aviation terms used in landing and take-off, words and phrases exchanged between the pilot and the control tower, terms for the parts of the aircraft, and the components of the aircraft and the devices in it.

Even if you are only interested in traveling and flying in the sky, you will benefit from learning these terms that you will be exposed to in any airport in the world, no matter where you travel or the language of the country you are traveling to.

Everyone knows that airlines have their own language, and there are many terms that are used only to describe places or situations specific to aviation. Let’s take a look to learn some of the Aviation terminology and its meanings.

First, you should recognize the term “flying”, it can be defined as no contact with the ground, with or without mobility, with or without landing gear.

Aviation has its own language of hundreds of aeronautical terms. Here you will find the most common aviation terms and some not-so-common ones. Some come from French, German, and even military usage, but remember that English is always the official language of aviation.


  • Absolute Altitude

The vertical distance between the aircraft and ground level.

  • Absolute Ceiling

At the highest altitude, an aircraft can fly at maximum throttle while maintaining level height and constant airspeed.

  • Accelerated Stall

A stall occurs at a higher airspeed than a normal stall due to a higher load factor (g).

  • Adverse yaw

Occurs when the plane’s nose turns away from the direction of the turn.

  • ADF (Automatic Direction Finder)

A navigation system that identifies the relative bearing of an aircraft based on a radio beacon transmitting in the MF or LF bandwidth.

  • Adiabatic Lapse Rate

The rate at which temperature changes due to increasing and decreasing altitude, under conditions of thermal equilibrium.

  • Adverse Yaw

When an aircraft turns in the opposite direction of a roll due to the use of ailerons and the difference in lift and drag of each wing.

  • Aeronautical Decision-Making

Training and planning to make the best and safest decisions to mitigate risk.

  • Aeronautical Information Manual (AIM)

An official Federal Aviation Administration (FAA) publication that details proper pilot operation within the US National Airspace System, including Air Traffic Control (ATC) and aviation safety.

  • AGL – (Above Ground Level)

The vertical distance is measured between the aircraft and a specific land mass.

  • Aileron

The movable, hinged flight control surfaces are used in pairs with opposite motions to control the roll of an aircraft. Learn more about the parts of an airplane.

  • AIM (Aeronautical Information Manual)

Official guide published by the FAA to instruct pilots on how to operate inside the U.S. National Airspace System with regard to flight information, ATC, etc.

  • Air Defense Identification Zone (ADIZ)

The airspace over both water and land within which the identification, location, and control of civil aircraft are required in the interest of national security.

  • Airfoil

The cross-sectional shape of a wing, blade, turbine, or rotor that produces lift.

  • Airline

A company or organization that offers regularly scheduled flights and routes.

  • Airspace Classes

The different types of airspace are defined by ICAO and adopted around the world. They include controlled, uncontrolled, and particular use of airspace.

  • Air Speed Indicator (ASI)

A pitot-static flight instrument that indicates the airspeed of an aircraft through an air mass in miles per hour, knots, or both.

  • Air Taxi Operator

An aircraft company that operates under FAR Part 135. The aircraft must be originally designed to have no more than 60 passenger seats or a cargo payload of 18,000 lbs and carries cargo or mail on either a scheduled or charter basis, or carries passengers on an on-demand basis or limited scheduled basis.

  • Alpha Code

The NATO Phonetic Alphabet is used by pilots to communicate clearly with ATC and other pilots.

  • Altimeter

An instrument that measures an object’s altitude above a fixed surface.

  • Altitude Indicator

An instrument that indicates aircraft orientation relative to the earth’s horizon.

  • AMT

Abbreviation for Aviation Maintenance Technician, which is another term for an aircraft mechanic.

  • AME

Aviation Medical Examiner

  • The angle of Attack

The angle between a reference line on an airfoil and the direction of the oncoming air.

  • The angle of Incidence

The angle at which a reference line on an airfoil is perpendicular to the aircraft’s longitudinal surface axis.

  • Anhedral

The downward angle of aircraft wings from the horizontal cross-section of the wings.

  • Annual Inspection

A required aircraft inspection every 12 calendar months.

  • A&P

Aircraft and Powerplant Mechanic

  • Approach

The phase of flight is when the pilot intends to land on the runway. There are different types of approaches, depending on whether the pilot is flying VFR or IFR.

  • Apron

The paved area at an airport where aircraft park, fuel, load, and unload.

  • ATC (Air Traffic Control)

A ground-based service that ensures the safety of air traffic by directing aircraft in the area during take-off, landing, and while flying in the designated airspace. Epic’s ATC is KEVB.

  • ATIS (Automatic Terminal Information Service)

A continuous broadcast of pre-recorded aviation information is available to pilots around specific terminals. The information is constantly updated and designed for the mass spreading of relevant information, which is particularly useful at busy airports.

  • Avionics Master Switch

A single switch that controls the electrical power for an aircraft’s electronic communication and navigation instruments.

  • AWIS

Aviation Weather Information Service.


  • Base Leg

The flight path is in an airport pattern that runs in the runway landing direction.

  • Baseline

The minimum or starting point is used for comparison.

  • Best Lift Over Drag Ratio

Often referred to as ‘L over D Max’, this is the highest value of ratios of lift to drag for any airfoil.

  • Blade Angle

The angle between the reference line of a propeller blade and a plane perpendicular to the axis of rotation.

  • Bleed Air

Hot compressed air is produced during the compressor stage of aircraft engine operation.


  • Cabin Crew

The airline staff members are responsible for the safety and comfort of passengers during flight, typically the flight attendants.

  • Calibrated Airspeed

The indicated airspeed was corrected for position and instrument error.

  • Camber

The convexity of the curve on an aircraft wing.

  • CAVU (Ceiling and Visibility Unlimited)

Describes ideal flying conditions with visibility of 10 or more miles and a ceiling of at least 10,000 feet.

  • Cargo

Goods carried on an aircraft.

  • Ceiling

The height of the lowest cloud layer or obscuring phenomena that are reported as “broken”, “overcast”, or “obscuration”, and not classified as “thin” or “partial”.

  • Center of Gravity (CG)

The longitudinal and lateral point over which the aircraft would balance.

  • Charter

The business of renting all seats on an aircraft rather than a commercial flight where seats are sold individually.

  • Chord Line

The imaginary straight line runs between the airfoil’s leading and trailing edges.

  • Clearance

The authorization provided by air traffic control for aircraft to proceed with a particular action in controlled airspace is designed to prevent aircraft collisions.

  • Climb

The act of increasing aircraft altitude, typically to a designated level.

  • Cockpit

The cockpit of a plane is located at the front. It contains the instrument panel and pilot seats. Learn more about the parts of an airplane.

  • CofA

Certificate of Airworthiness

  • Common Traffic Advisory Frequency (CTAF)

A radio frequency is used for air-to-air communication, allowing continued aircraft operation at non-towered airports or outside of tower operating hours.

  • Commuter

An aircraft category outlined by the FAA as “limited to propeller-driven, multi-engine airplanes that have a seating configuration, excluding pilot seats, of 19 or less, and a maximum certificated takeoff weight of 19,000 pounds or less.

The commuter category operation is limited to any maneuver incident to normal flying, stalls (except whip stalls), and steep turns, in which the angle of bank is not more than 60 degrees.”

  • Constant-Speed Propeller

A propeller is designed to maintain a consistent engine RPM by automatic increases and decreases of the blade pitch.

  • Contrail

A streak of condensed water vapor in the air due to the heat produced by aircraft engines at high altitudes.

  • Controlled Airspace

Designated airspace within which Air Traffic Control provides aircraft movement instructions and regulations.

  • Course Deviation Indicator (CDI)

A navigational instrument that displays the lateral course deviation. When the aircraft is flying left of the selected course, the needle deflects proportionally to the right. When the aircraft is flight right of the selected course, the needle deflects proportionally to the left.

  • Cross-Country Flight (XC)

A cross-country flight requires special flight planning. This is required by the FAA to earn your PPL. A pilot must land at an airport other than the place of departure. Three full-stop landings are required.

  • Crosswind

The wind is blowing perpendicular to the aircraft course.


  • DA – Density Altitude

Density altitude is the air density given as a height above mean sea level. The density altitude is considered to be the pressure altitude adjusted for a non-standard temperature.

  • Descent

The act of decreasing aircraft altitude, typically to a designated level.

  • Distance Measuring Equipment (DME)

Radio navigation technology is used to measure the distance between the aircraft and a ground station.

  • Distress

An internationally-recognized signal of danger and need for immediate assistance.

  • DME

Designated Mechanic Examiner

  • Dogfight

A close-range aerial battle between two aircraft. These occurred in every war involving planes until 1992.

  • Downwind Leg

A flight path parallels but runs in the opposite direction of the runway intended for landing.

  • Drag

A parallel and opposing force to an aircraft’s motion through the air.


Direct User Access Terminal Service.


  • EASA

European Aviation Safety Agency.

  • Elevator

Horizontal surfaces that control aircraft pitch are typically hinged to the stabilizer.

  • Empennage

Another phrase for the tail of an aircraft is, which provides stability during flight. Learn more about the parts of an airplane.

  • ETA – Estimated Time of Arrival

The time you will arrive at a destination, is based on the local time.

  • ETD – Estimated Time of Departure

The time you plan to depart.

  • ETE – Estimated Time en Route

The amount of time you will spend traveling to a destination.


  • FAA – Federal Aviation Administration

The governing body of civil aviation in the United States.

  • FARs – Federal Aviation Regulations

FAA rules governing aviation in the U.S.

  • FBO – Fixed-Base Operator

An airfield operation where pilots may find fuel and other services.

  • Feathering

The act of adjusting variable pitch propellers so that the blades are in line with airflow and don’t create air resistance.

  • Ferry Flight

A flight intended to return an aircraft to base; deliver a new aircraft from the manufacturer to the purchaser; move an aircraft from one operations base to another, or move an aircraft for the purpose of maintenance.

  • Final Approach

A flight path running in the direction of the runway intended for landing ends with a landing.

  • Firewall

A fire-resistant bulkhead is situated between the engine and other aircraft areas.

  • “Five by five”

Radio receptions are loud and clear on a scale of 1 to 5

  • Fixed Base Operator (FBO)

An organization at an airport that offers aviation services, such as hangar, parking, and tie-down space; airplane maintenance and rentals; and fuel.

  • Flaps

Flaps are a kind of high-lift device used to increase the lift of an aircraft wing at a given airspeed. Flat devices, typically located on the edges of an aircraft wing, that control lift at specific speeds.

  • Flare

A maneuver that typically occurs during the landing stage of an aircraft. The aircraft’s nose is pointed upwards, which lowers the descent rate in preparation for landing.

  • Flight Bag

A pilot flight bag is used to carry required documents and helpful tools, such as a kneeboard, headset, and checklists.

  • Flight Computer

Many pilots rely on the E6B flight computer to calculate fuel use, wind direction, etc.

  • Flight Deck

An area at the front of the airplane where the pilot and aircraft controls are situated – in other words, the cockpit.

  • Flight Plan

A flight Plan is a Formatted information provided by pilots or dispatchers regarding an upcoming flight, including details such as destination, path, timing, etc.

  • Flying Dirty

Flying with extendable surfaces in their extended states to create the drag, such as flaps extended and landing gear out.

  • F/O – First Officer

Second in command of the aircraft

  • Fog

Fog is a thick cloud of tiny water droplets at or near Earth’s surface that obscures visibility

  • FSDO

Flight Standards District Office – Local authority overseen by the FAA

  • FSS – Flight Service Station

An air traffic facility that provides information and services to pilots.

  • Fuselage

The central portion of an aircraft is intended to house the flight crew, passengers, and cargo. Learn more about the parts of an airplane.


  • General Aviation

The division of civil aviation aircraft operations includes all but commercial air transport and aerial work.

  • Glass Cockpit

A term used to describe an aircraft that is fully equipped with electronic, digital flight instrument displays, instead of analog-style gauges.

  • “George”

Nickname is given to the autopilot system

  • Go-Around

A go-around occurs when the pilot abandons a landing and goes around the flight pattern before attempting to land.

  • Gross Weight

The aircraft weight includes people, cargo, fuel, etc.

  • Ground Effect

The increasing lift and decreasing drag occur as a result of an aircraft’s wings as it gets closer to the ground.

  • Groundspeed

The horizontal speed of an aircraft relative to the surface below.


  • Hand-off

The action was taken by ATC to transfer the radar identification of an aircraft to another controller.

  • Handshake

The initial interaction or ‘greeting’ between two computers. Aircraft communicate with satellites for location purposes. Aeronautical satellite communication (SATCOM) systems are used to transmit messages from the cockpit as well as automated messages from onboard systems.

During these communications, a log-on request occurs, often called a ‘ping.’ This process of interrogating the terminal is known as the handshake.

  • Hangar

A building made to hold aircraft for storing, maintenance, assembly, etc.

  • Heavy

ATC uses this term to refer to larger aircraft with a maximum takeoff weight of 136 tonnes or more.

  • Horizontal Stabilizer

The horizontal stabilizer prevents the up-and-down or pitching, the motion of the aircraft’s nose.

  • Hypoxia

A condition caused by low levels of oxygen that can lead to dizziness, disorientation, etc, posing extreme danger to pilots operating aircraft at high altitudes.


  • ICAO

 International Civil Aviation Organization – A specialized agency of the United Nations. Supports aviation and navigation around the globe.

  • ILS

Instrument Landing System – A system that uses radio waves to assist landings in IFR conditions.

  • Instrument Flight Rules (IFR)

Regulations that define aircraft operations when pilots are not able to operate using visual references.

  • Instrument Landing System(ILS)

A ground-based system that provides directional information for aircraft attempting to land in low visibility situations.

  • Indicated Airspeed (IAS)

The speed of an aircraft is displayed on the airspeed indicator, which is determined by the pitot-static tube and does not take into account any outside factors.

  • Instrument Meteorological Conditions (IMC)

Weather conditions describe a situation where pilots are not able to operate using visual references.


  • Jet

An aircraft propelled by one or more jet engines.

  • Joystick

The control column in the aircraft is often called a joystick. It is the main device that controls the aircraft and is typically mounted on the ceiling or floor if the aircraft has a joystick instead of a yoke.


  • KCAS

Knots Calibrated Airspeed – Indicated airspeed corrected for instrument and position error

  • KIAS

Knots Indicated Airspeed – Read directly from the airspeed indicator

  • Kneeboard

Pilots attach a kneeboard to their thigh as a clipboard tool to organize tools, charts, etc.

  • Knot

A measurement of speed that takes into account nautical miles: 1 knot = 1 nautical mile per hour = 6076 feet per hour. 1 mph =1 mile per hour = 5280 feet per hour.

  • KTAS

Knots True Airspeed – The speed of the aircraft relative to the airmass in which it is flying.


  • Laminar-Flow Airfoil

The smooth airflow over an aircraft wing with minimized drag.

  • Lift

The force that directly opposes aircraft weight, is generated primarily by the wings.

  • Load Factor (g)

The smooth airflow over an aircraft wing with minimized drag.

  • Longitudinal Axis

The directional runs horizontally from the aircraft’s nose to the tail.


  • Mach

The ratio of aircraft speed to the speed of sound through the medium where the aircraft is traveling.

  • Magnetic Compass

The directional orientation of an aircraft according to the geomagnetic field.

  • Magnetic Deviation

The error is produced by the unavoidable magnetic impact of aircraft materials.

  • Magnetic North

Unlike the geographical north (North Pole), this point is the location indicated as North by where the compass points.

  • Magneto

An aircraft engine component that generates high voltage to ignite spark plugs.

  • Mean Sea Level (MSL)

The average level of the surface of an ocean is used as a basis for vertical measurements.


A pilot weather report is delivered on a continuous basis.

  • Morse Code

Pilots learn Morse code to identify aircraft call signs since NDBs and VORs still send their identifying letters this way.

  • MSL

Mean Sea Level – Average level of the surface of one or more of Earth’s bodies of water from which heights such as elevation may be measured.

  • MTOW

Maximum Take-Off Weight.


  • Narrow-Body Aircraft

A smaller type of aircraft that has a single-aisle inside. It can carry 4 to 300 passengers.

  • Naval

Relating to ships or a navy.

  • NDB

Non-directional beacon is a radio transmitter at a know location used as a navigation aid.

  • NOTAMs

Abbreviation for “Notices to airmen.” which are published notices provided to pilots prior to flights advising them of relevant circumstances in real-time.


  • OAT

Outside Air Temperature

  • Operating Limitations

Restrictions defined by an aircraft manufacturer include airspeed, weight, etc.

  • Oshkosh

“Oshkosh” refers to the annual EAA AirVenture Air Show in Oshkosh, Wisconsin. It is held every July.

  • Overshoot

Landing aircraft beyond the runway.


  • Payload

The weight of the content carried in an aircraft, including passengers, pilots, cargo, etc.

  • Pilot in Command (PIC)

The designated individual is responsible for safe aircraft operations during flight.

  • PIREP – Pilot Report

Report to ATC made by a pilot during flight or after landing describing actual weather conditions.

  • Pitch

The movement of an aircraft is characterized by the nose and tail rising and falling.

  • Pitot Tube

A small device located on the front outside edge of an airfoil is used to measure air pressure.

  • POH

Pilot’s Operating Handbook – An aircraft flight manual containing pertinent safety information.

  • Primary Flight Display (PFD)

The main screen used by pilots in aircraft contains an electronic flight instrument system.

  • Propeller

A piece of aircraft equipment that contains rotating blades, creating engine thrust. Learn more about the parts of an airplane.


  • QAR

Quick Access Recorder – An airborne flight recorder that provides quick and easy access to raw flight data through a USB or cellular network.

  • Quadraplane

An aircraft that has 4 wings of the same size


  • Roll

Aircraft rotation along the longitudinal axis, which runs from the nose to the tail.

  • Rudder

An aircraft surface is used to control the yaw movement.

  • Runway (RWY)

A “defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft”.

  • Runway End Safety Area (RESA)

A surface located beyond the runway is designated as a place for aircraft to enter in an attempt to minimize risk during unplanned occurrences, such as an overshoot.


  • Second in command (SIC)

The designated individual to take over flight operations from the PIC.

  • Short Field

A runway that is shorter in length and requires aircraft to minimize the amount of runway used when taking off or landing.

  • Sideslip

An aircraft movement that typically aligns with the lateral force of the wind and results in a sideways flow.

  • Skid

The sliding and outward pivoting movement of the aircraft occurs as a result of a shallow turn.

  • Slip

The sliding and inward pivoting movement of the aircraft occurs as a result of a steep turn.

  • Soft Field

A runway that is not paved and made of elements such as dirt or grass.

  • Squawk

A four-digit transponder code is given to an aircraft by ATC to allow for simple identification of an aircraft in a given region.

  • Stability

Aircraft are subject to static, dynamic, longitudinal, lateral, and directional stability that impacts flying conditions.

  • Stall

The condition that occurs as a result of an aircraft exceeding its angle of attack and therefore experiencing decreased lift.

  • Standard Rate Turn

A turn that an aircraft makes at a rate of 3°/second or a 360° turn in two minutes.

  • Straight-and-Level Flight

Maintaining a consistent heading and altitude during flight.


  • Tail

The rear aircraft structure provides aerodynamic stability.

  • Tarmac

The paved area at an airport where aircraft park, fuel, load, and unload.

  • Threshold

The area of a runway is designated with particular markings, indicating the beginning of a runway.

  • Throttle

A device that controls the amount of power outputted by the engine.

  • Thrust

A force that opposes aircraft drag and is created by the engines to propel the aircraft forward.

  • Torque

A force that is intended to produce rotation.

  • Touch-and-Go

An aircraft maneuver is used to practice landing techniques by simply landing on the runway and taking off once more without coming to a full stop.

  • Transponder

An electronic device on airplanes that generate an output code, which is used for ATC identification purposes, also known as ‘squawk’.

  • Trim Tab

Small surfaces on the trailing edge of a bigger control surface are used to counteract the aerodynamic forces on the bigger control surface.

  • True Airspeed

The speed of an aircraft is the speed corrected for the errors caused by altitude and temperature.

  • True Altitude

The vertical height of an aircraft above Mean Sea Level (MSL).

  • Turbulence

A sudden violent shift in airflow caused by irregular atmospheric motion.

  • TWR


  • TWY



  • Upwind Leg

The flight path in an airport pattern runs parallel to the runway landing direction, along the same direction the aircraft will be landing.

  • Useful Load

The weight of the items that can be taken out of the aircraft, including fuel, passengers, cargo, pilots, etc.

  • UTC

Universal Time Coordinated – The primary time standard used to regulate clocks and time around the world.


  • V Speed

Approximately 20 standard terms are used to describe airspeeds important or useful to the operation of all aircraft, such as Vne speed, which means “never exceed speed” or Vmo, which means “maximum operating speeds. Each aircraft has its own unique V speed.

  • Vertical Speed Indicator (VSI)

A device that provides the feet per minute (fpm) rate at which an aircraft is climbing or descending.

  • Very High Frequency (VHF) Omni-Directional Range (VOR)

A short-range radio aircraft navigation system allows aircraft to receive directional information through radio signals from ground-based beacons.

  • Visual Flight Rules (VFR)

Visual Flight Rules (VFR) are Regulations that define aircraft operations when pilots are able to operate using visual references.

  • VFR On Top

In the condition where IFR conditions exist, however, VFR conditions are exactly above the cloud layer.

  • Visual Meteorological Conditions (VMC)

Weather conditions describe a situation where pilots are able to operate using visual references.


  • Weight-Shift-Control

A method used by pilots to steer a hang glider or paraglider whereby they push a control bar attached to the wing structure.

  • Wide-Body Aircraft

An aircraft with two aisles inside. The typical fuselage diameter is 16 to 20 feet.

  • Wind Shear

An abrupt change in horizontal or vertical wind direction.

  • Wx



  • XC



  • Yaw

The movement of an aircraft around the vertical axis is characterized by the nose moving side-to-side. The rudder controls yaw.

  • Yoke

The aircraft control devices are used by pilots for changes in attitude, as well as pitch and roll movement.


  • Zulu Time

A term is synonymous with UTC (Universal Coordinated Time), which is the same as Greenwich Mean Time. Pilots file all flight plans in Zulu Time.

Letter on Boarding pass

What do the letters on your boarding pass really mean and the combination you never want to see?

You might think the technical stuff on your boarding pass is just random letters and not all that important – but it turns out each has a hidden meaning, and one is really sinister


If you’ve ever seen this on your boarding pass, you might be in trouble.

The letters are a special code that stands for Secondary Security Screening Selection and they were designed by the USA’s Transportation Security Administration (TSA) for flights using American airspace.


It means you are in the most basic class. It stands for the economy seats and is usually the cheapest one on board. If you find a Q on your pass, it means you’ve booked one of the cheapest fares and will not be eligible for a free upgrade.

An E is the class between basic and first-class – Premium Economy. Those with a C or a J on their ticket are traveling business class, either have an airline account or are frequent flyers.