Aviation Terms Glossary: Pilot Jargon Decoded

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Welcome to Aviamonde’s aviation terms glossary. Whether you’re a budding pilot, an aviation enthusiast, or a frequent traveler, I’ll help you decode aviation jargon from basic terms to complex concepts.

Aviation has its unique language and nuanced terminology. Whether you’re curious about the function of an “altimeter” or the meaning of “yaw,” the definitions you’re after are only a click away.

I’ve put together an extensive selection of aeronautical terms, airline lingo, and pilot jargon, providing you with a thorough and reliable resource. I regularly add and revise terms to maintain this glossary’s relevance and accuracy.

Common Aviation Terms and Notable Organizations

Aviation Alphabet — Standardized set of words used to spell out letters in radio communication.

Black box (though bright orange for easier recovery) — Term, and misnomer, for the flight data recorder (FDR) that records aircraft flight data and cockpit voice recorder (CVR) that records cockpit audio to aid in accident investigation.

Codeshare — Business arrangement between airlines where they share and market the same flight under their own airline codes.

Deadhead — Crew member traveling as a passenger to reposition for their next flight.

Flight Plan — Document prepared by a pilot or flight dispatcher before departure, outlining the intended route, altitude, speed, and other relevant information.

George — Nickname for the autopilot system, possibly a reference to King George VI or George De Beeson.

International Civil Aviation Organization (ICAO) — United Nations agency established to help countries share their skies to their mutual benefit, with a focus on setting international standards and regulations for civil aviation.

International Air Transport Association (IATA) — Trade association for the world’s airlines that represents and serves airlines with advocacy and global standards for safety, security, efficiency, and sustainability.

European Union Aviation Safety Agency (EASA) — EU agency founded to promote and achieve the highest common standards of safety and environmental protection in civil aviation across Europe.

Federal Aviation Administration (FAA) — US government agency that regulates and oversees civil aviation in the United States, including air traffic control, aircraft certification, and pilot licensing.

Aircraft Owners and Pilots Association (AOPA) — US non-profit organization that advocates for general aviation, particularly supporting the interests of aircraft owners and pilots.

Experimental Aircraft Association (EAA) — US-based international organization that encourages and supports the flying, building, and restoration of recreational aircraft.

Aviation Terms List in Alphabetical Order

A

Absolute Altitude — Actual height above the surface of the earth or Above Ground Level (AGL).

Absolute Ceiling — Highest altitude at which an aircraft can maintain level flight.

Acceleration Error — Magnetic compass error that occurs when the aircraft accelerates while flying on an easterly or westerly heading, causing the compass card to rotate toward North.

Adverse Yaw — Tendency of the airplane to yaw in the opposite direction of a turn.

Aerobatics — Flying maneuvers involving abrupt changes in aircraft’s attitude, speed, and acceleration.

Aerodrome — Defined area on land or water intended for the arrival, departure, and surface movement of aircraft.

Aeronautical Chart — Type of map used in air navigation that contains topographic features, hazards and obstructions, navigation aids, navigation routes, designated airspace, and airports.

Aeronautical Decision Making (ADM) — Systematic approach to the mental process used by pilots to consistently determine the best course of action in response to a given set of circumstances.

Ailerons — Primary flight control surfaces that control roll and are mounted on the trailing edge of an airplane wing, near the tip, which control roll.

Aircraft Approach Category — Performance grouping of aircraft based on a speed of 1.3 times the stall speed in the landing configuration at maximum gross landing weight.

Airfoil — Any surface, such as a wing, propeller, or rudder, which provides aerodynamic force when it interacts with a moving stream of air.

Airplane — Engine-driven, fixed-wing, heavier-than-air aircraft that is supported in flight by the dynamic reaction of the air against its wings.

Airspace — Air available to aircraft to fly in, especially the part subject to the jurisdiction of a particular country.

Airspeed Indicator — Differential pressure gauge that displays airspeed, typically in knots, by measuring the dynamic pressure of the air through which the aircraft is flying.

Airway — Designated air route based on a centerline that extends from one navigation aid or intersection to another navigation aid (or through several navigation aids or intersections).

Airworthiness Certificate — Certificate issued by the appropriate aviation authority to attest that an aircraft is in a condition for safe operation.

Air Traffic Control (ATC) — Service that provides management of aircraft movement and separation through ground-based personnel in a particular section of controlled airspace.

Alternate Airport — Airport designated in an IFR flight plan that provides a suitable destination if a landing at the intended airport becomes inadvisable.

Altimeter — Flight instrument that indicates altitude by sensing pressure changes.

Altimeter Setting — Barometric pressure setting used to adjust a pressure altimeter for variations in atmospheric pressure and temperature.

Angle of Attack — Angle between the airfoil’s chord line and the relative wind.

Angle of Incidence — Angle between the chord line of the wing and the longitudinal axis of the airplane.

Aspect Ratio — Span of a wing divided by its average chord.

Anhedral — Downward slant from root to tip of an aircraft’s wing or horizontal tail surface.

Anti-icing — Process or system designed to prevent the accumulation of ice on an aircraft structure by using heat or by covering the surface with a chemical that prevents water from reaching the surface.

Apron (commonly referred to as Ramp in the US) — Defined area in an airport intended to accommodate aircraft for purposes of loading or unloading passengers or cargo, refueling, parking, or maintenance.

Asymmetric Thrust (also known as P Factor) — Tendency for an aircraft to yaw to the left due to the descending propeller blade on the right producing more thrust than the ascending blade on the left.

Attitude Indicator — Flight instrument that reflects the airplane’s attitude in relation to the horizon.

Autopilot — Automatic flight control system that keeps an aircraft in level flight or on a set course through pilot or navigation station guidance.

Auxiliary Power Unit (APU) — Compact onboard engine in aircraft that powers essential systems like air conditioning and electricity, especially useful when the plane is on the ground or during emergencies

Aviation Medical Examiner (AME) — Physician with training in aviation medicine designated by the local aviation authority to perform flight physical examinations and issue aviation medical certificates.

B

Barber Pole — Red and white striped needle on an airspeed indicator that indicates the maximum operating speed or Mach number.

Base Leg — Transitional segment of the traffic pattern following the downwind, flown at a right angle to the runway to position the aircraft to turn onto the final approach.

Basic Empty Weight — Standard empty weight plus optional and special equipment that has been installed.

Bearing — Horizontal direction to or from any point, usually measured clockwise from true north (true bearing), magnetic north (magnetic bearing), or some other reference point, through 360°.

Best Angle of Climb Airspeed (Vx) — Airspeed which produces the maximum gain in altitude for horizontal distance traveled.

Best Rate of Climb Airspeed (VY) — Airspeed which produces the maximum gain in altitude per unit of time.

Biplane — Airplane with two sets of wings.

Blade Angle — Angle between the reference line of a propeller blade and a plane perpendicular to the axis of rotation.

Blast Pad — Surface adjacent to the ends of a runway provided to reduce the erosive effect of jet blast and propeller wash

Bracketing — Navigation technique that involves making adjustments for wind drift to maintain a desired course.

Bleed Air — Compressed air that’s taken from the compressor stage of an engine for use in several systems, including air conditioning, pressurization, and de-icing.

Block Altitude — Block of altitudes assigned by ATC to allow altitude deviations.

C

Cabin Altitude — Cabin pressure in terms of equivalent altitude above sea level.

Calibrated Airspeed (CAS) — Indicated airspeed of an aircraft, corrected for installation and instrument errors.

Calibrated Altitude — Indicated altitude corrected to compensate for instrument error.

Camber — Curve of an airfoil section from the leading edge to the trailing edge.

Canard — Horizontal surface mounted ahead of the main wing to provide longitudinal stability and control.

Ceiling — Height above the earth’s surface of the lowest layer of clouds which is reported as broken or overcast or the vertical visibility into an obscuration.

Center of Gravity (CG) — Point where the entire weight of the airplane is considered to be concentrated.

Center of Pressure (CP) — Point along the wing chord line where lift is considered to be concentrated.

Changeover Point (COP) — Point along the route or airway segment between two adjacent navigation facilities or waypoints where changeover in navigation guidance should occur.

Checklist — Systematic and sequential list of items that must be performed to properly accomplish a task.

Chord Line — Imaginary straight line between the leading and trailing edges of an airfoil section.

Clean Configuration — Configuration in which all flight control surfaces have been placed to create minimum drag.

Clearance — ATC permission for an aircraft to proceed under specified traffic conditions within controlled airspace.

Clear Air Turbulence (CAT) — Type of turbulence that occurs at high altitudes without visible cues like clouds, caused by factors such as pressure changes and jet streams, making it sudden and unpredictable.

Clearing Turns — Turns consisting of at least a 180° change in direction, allowing a visual check of the airspace around the airplane to avoid conflicts while maneuvering.

Clearway — Defined rectangular area beyond the end of a runway cleared or suitable for use in lieu of runway to satisfy takeoff distance requirements.

Complex Aircraft — Aircraft with retractable landing gear, flaps, and a controllable-pitch propeller.

Compressor Stall — Condition in gas turbine engines where an axial-flow compressor in which one or more stages of rotor blades fail to pass air smoothly to the succeeding stages.

Cone of Confusion — Inverted cone-shaped area above a VOR station where no signal is received, causing erroneous indications.

Configuration — Position of the landing gear and flaps or layout of aircraft interior space and seating.

Constant-speed Propeller — Controllable-pitch propeller whose pitch is automatically varied in flight by a governor to maintain a constant rpm in spite of varying air loads.

Contrail (short for condensation trail) — visible trail of condensed water vapor and ice crystals left behind by aircraft at high altitudes, formed when hot engine exhaust mixes with cold air.

Controllable-pitch Propeller — Propeller with blades that can be rotated around their long axis to change their pitch.

Controlled Airport — Airport that has an operating control tower.

Controlled Airspace — Airspace of defined dimensions within which ATC service is provided to IFR and VFR flights in accordance with the airspace classification.

Conventional Landing Gear (also referred to as tailwheel) — Type of landing gear where the two main wheels are located on either side of the fuselage and a third wheel, the tail wheel, is positioned at the rear of the airplane.

Course — Intended or desired direction of flight in the horizontal plane measured in degrees from true or magnetic north.

Cowl Flaps — Shutter-like devices arranged around certain air-cooled engine cowlings, which may be opened or closed to regulate the flow of air around the engine.

Crab — A maneuver used to counteract the drift of an aircraft caused by a crosswind. The pilot will offset the heading of the aircraft from the desired track by a calculated amount, and the aircraft’s velocity combined with the wind through vector addition will give a net movement in the desired direction.

Critical Altitude — Maximum altitude under standard atmospheric conditions at which a turbocharged engine can produce its rated horsepower.

Critical Angle of Attack — Angle of attack at which a wing stalls regardless of airspeed, flight attitude, or weight.

Cross-check — Continuous and logical observation of instruments for attitude and performance information.

Crosswind — Wind that’s not parallel to a runway or the path of an aircraft.

D

Dead Reckoning — Navigation method used to estimate a position by calculating based on previously known positions, time, speed, distance, and direction.

Deceleration Error — Magnetic compass error that occurs when the aircraft decelerates while flying on an easterly or westerly heading, causing the compass card to rotate toward the South.

Decision Altitude (DA) — Specified altitude in the precision approach, charted in feet MSL, at which a missed approach must be initiated if the required visual reference to continue the approach has not been established.

Decision Height (DH) — Specified altitude in the precision approach, charted in height above threshold elevation, at which a decision must be made either to continue the approach or to execute a missed approach.

Decompression — Failure of aircraft pressurization system to maintain the designated cabin pressure, which often occurs from system malfunctions or structural damage.

Differential Ailerons — Control surfaces configured in a manner where the aileron moving upward undergoes a greater deflection than the aileron moving downward.

Density Altitude — Pressure altitude corrected for nonstandard temperature, used in computing aircraft and engine performance.

Deviation — Compass error caused by magnetic disturbances from electrical and metal components in the airplane.

Dihedral — Upward angle formed between the wings of an aircraft and the horizontal axis.

Displaced Threshold — Threshold located at a point on the runway other than the designated beginning of the runway, usually to avoid obstacles or provide additional landing distance.

Distance Measuring Equipment (DME) — Equipment (airborne and ground) to measure, in nautical miles, the slant range distance of an aircraft from the navigation aid.

Ditching — Controlled emergency landing of aircraft on water.

DME Arc — Flight track that is a constant distance from the station or waypoint.

Downwind Leg — Traffic pattern leg where an aircraft flies parallel to the runway but opposite to the landing direction (i.e., in the same direction as the prevailing wind).

Drag — Aerodynamic force that opposes thrust and relative motion of aircraft through the air.

Drift Angle — Angle between heading and track.

Dry Lease — Type of lease in which the aircraft is provided with no crew and maintenance guarantees.

Dutch Roll — Combined rolling and yawing motion in an aircraft, typically occurring when dihedral effects overpower directional stability.

E

Elevation — Height of a ground feature, obstacle, or station above mean sea level (MSL).

Elevator — Horizontal, movable primary control surface in the tail section, or empennage, of an airplane.

Emergency Evacuation — Rapid and urgent disembarkation of an aircraft by passengers and crew using all available exits due to an immediate threat to safety.

Emergency Landing — Unplanned landing made by an aircraft due to an urgent situation such as mechanical failure, medical emergency, or adverse weather conditions.

Emergency Locator Transmitter (ELT) — Automatically or manually activated, battery-operated radio transmitter carried aboard aircraft to broadcast distress signals on designated frequencies to help locate aircraft in the event of a crash.

Exit Row — Row of seats where passengers are seated next to emergency exits and are responsible for assisting with their operation during an evacuation.

Empennage — Section of the airplane which consists of the vertical stabilizer, the horizontal stabilizer, and the associated control surfaces.

Endurance — Amount of time an aircraft can remain airborne with a given amount of fuel under specific conditions.

F

False Horizon — Optical illusion where pilots, particularly at night or in low visibility conditions, misjudge the natural horizon, often mistaking bright stars, city lights, or the edge of large bodies of water for the actual horizon, leading to spatial disorientation.

Feathering — Adjusting the pitch of a propeller blade so that its chord line aligns parallel to the airflow, optimizing aerodynamic efficiency.

Ferry Flight (also known as positioning flight) — Flight conducted to return an aircraft to its base, deliver it to a customer, transfer it between bases, or move it to or from a maintenance facility.

Final Approach (commonly shortened to Final) — Last leg in an aircraft’s approach to landing, when the aircraft is lined up with the runway and descending for landing.

First Officer (FO) — Also known as co-pilot, second-in-command pilot who assists the captain in operating an aircraft, generally sitting on the right seat of a fixed-wing aircraft and the left seat of a helicopter

Fix — Specific geographic location identified through visual reference, radio navigational aids (NAVAIDs), celestial navigation, or other navigational methods.

Fixed-Base Operator (FBO) — Business at an airport that offers aviation services like fueling, aircraft maintenance, aircraft rental, flight training, and other amenities to general aviation operators and private aircraft owners.

Fixed-pitch Propeller — Propeller with fixed blade angles.

Fixed-wing Aircraft — Heavier-than-air aircraft using stationary wings to generate lift through forward motion.

Flameout — Condition in the operation of a gas turbine engine in which the fire in the engine goes out due to either too much or too little fuel sprayed into the combustors.

Flaps — Hinged surfaces on the trailing edge of aircraft wings, positioned between the fuselage and ailerons, used to increase lift and drag for takeoff and landing.

Flare — Maneuver during landing where the pilot raises the aircraft’s nose to reduce descent rate and ensure a smooth touchdown.

Flight Deck — Forward compartment, or cockpit, of a large airplane that houses pilot seats, aircraft instruments and flight controls.

Flight Director — Aircraft system that provides real-time pitch and roll guidance, enabling the autopilot or pilot to maintain a desired flight path.

Flight Level (FL) — Aircraft altitude expressed in hundreds of feet, with the altimeter set to a standard pressure of 29.92 inches of mercury (inHg) or 1013.25 hectopascals (hPa).

Flight Management System (FMS) — Aircraft system that provides pilot and crew with highly accurate and automatic long-range navigation capability, blending available inputs from long- and short-range sensors.

Flight Path — Line, course, or track along which an aircraft is flying or is intended to be flown.

Flight Service Station (FSS) — Air traffic facility that provides a variety of services to pilots, including weather briefings, opening and closing flight plans, and search and rescue operations.

Foreign Object Damage (FOD) — Damage to aircraft components, especially engines, caused by the ingestion or impact of external objects like debris, birds, or tools.

Form Drag — Aerodynamic resistance caused by the shape and size of an aircraft or its components as they move through the air.

Fuel Dumping — Controlled jettison of fuel during flight to reduce an aircraft’s weight for safe landing.

Fuselage — Main part of an airplane that houses the cockpit, cabin, and cargo holds and provides attachment points for other major airplane components.

G

Glass Cockpit — Modern cockpit configuration in aircraft that replaces traditional mechanical flight instruments with electronic displays, predominantly LCD screens, typically featuring integrated flight management systems.

Glide Path —

Glide Slope (GS) — Part of the Instrument Landing System (ILS) that provides vertical guidance to aircraft on the final approach course.

Go Around — Procedure where a pilot abandons the landing approach and initiates a climb to a safe altitude, typically due to runway incursion, unstable approach, or ATC instructions.

Graveyard Spiral — The illusion of the cessation of a turn while still in a prolonged, coordinated, constant rate turn, which can lead a disoriented pilot to a loss of control of the aircraft.

Ground Effect — A usually beneficial influence on aircraft performance which occurs while you are flying close to the ground. It results from a reduction in upwash, downwash, and wingtip vortices which provide a corresponding decrease in induced drag. The condition of slightly increased air pressure below an airplane wing or helicopter rotor system that increases the amount of lift produced, results from a reduction in upwash, downwash, and wingtip vortices, and provides a corresponding decrease in induced drag.

Ground Power Unit (GPU) —

Groundspeed — Speed of the aircraft in relation to the ground.

H

Hangar —

Heading — The direction in which the nose of the airplane points with respect to true or magnetic north.

Heading Indicator (also called Direction Gyro) — An instrument that senses airplane movement and displays heading based on a 360° azimuth, with the final zero omitted.

Head-up Display (HUD) — A special type of flight viewing screen that allows the pilot to watch the flight instruments and other data while looking through the windshield of the aircraft for other traffic, the approach lights, or the runway.

Headwind —

Heavy —

High-Performance Airplane — An airplane having more than 200 horsepower, or retractable landing gear, flaps, and controllable-pitch propeller.

Holding — A predetermined maneuver that keeps aircraft within a specified airspace while awaiting further clearance

from ATC.

Holding Pattern — A racetrack pattern, involving two turns and two legs, used to keep an aircraft within prescribed airspace with respect to a geographic fix.

Homing — A method of navigating to an NDB by holding a zero relative bearing.

Horizontal Stabilizer —

Horizontal Situation Indicator (HSI) — A flight navigation instrument that combines the heading indicator with a CDI, in order to provide the pilot with better situational awareness of location with respect to the course line.

Hot Start — Engine start that occurs with normal engine rotation, but exhaust temperature exceeds

prescribed limits, usually caused by an excessively rich mixture in the combustor.

Hung Start — Condition of normal light off but with rpm remaining at some low value rather than increasing to the normal idle rpm, often the result of insufficient power to the engine from the starter.

Hydroplaning — A condition that exists when landing on a surface with standing water deeper than the tread depth of

the tires.

Hyperventilation — The excessive ventilation of the lungs caused by very rapid and deep breathing which results in an excessive loss of carbon dioxide from the body.

Hypoxia — The effects on the human body of an insufficient supply of oxygen.

I

Ident — Air Traffic Control request for a pilot to push the button on the transponder to identify return on the controller’s scope.

Indicated Airspeed (IAS) — Speed of an aircraft as shown on the airspeed indicator.

Indicated Altitude — Altitude shown by an altimeter set to the current altimeter setting.

Induced Drag — Part of total drag which is created by the production of lift. Induced drag increases with a decrease in airspeed.

Inertial navigation system (INS) — Computer-based navigation system that tracks the movement of an aircraft via signals produced by onboard accelerometers.

Instrument Flight Rules (IFR) — Rules that govern the procedure for conducting flight in weather conditions below Visual Flight Rules (VFR) weather minimums.

Instrument Meteorological Condition (IMC) —

Instrument landing system (ILS) — Electronic system that provides both horizontal and vertical guidance to a specific runway, used to execute a precision instrument approach procedure.

Interference Drag — Parasite drag caused by air flowing over one portion of the airframe interfering with the smooth flow of air over another portion.

Isogonic Lines — Lines on charts that connect points of equal magnetic variation.

J

Jeppesen Charts —

Jet Blast — Air stream exiting a jet engine’s exhaust, particularly on or before take-off, during taxiing, and while the aircraft is positioning itself at a gate.

Jet Engine —

Jet Lag —

Jet Stream — Narrow band of winds with speeds of 100 to 200 m.p.h. occurring between approximately 32,000 and 49,000 feet.

Jet Wash —

Jetway (also referred to as Jet Bridge) —

Jumbo Jet —

Jump Pilot —

Jump Seat —

K

Knot — Unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph

Kollsman Window —

L

Layover —

Leading Edge —

Lift — Upward force created by the effect of airflow as it passes over and under the wing.

Load Factor — Ratio of the load supported by the airplane’s wings to the weight of the aircraft and its contents.

Localizer (LOC) — Portion of an ILS that gives left/right guidance information down the centerline of the instrument runway for final approach.

M

Mach Number — Ratio of the true airspeed of the aircraft to the speed of sound in the same atmospheric conditions,

named in honor of Ernst Mach, late 19th century physicist.

Magnetic Bearing — Magnetic course you would fly to go direct to an NDB station.

Magneto — Self-contained, engine-driven unit that supplies electrical current to the spark plugs.

Maneuvering Speed (VA) — Maximum speed at which you can use full, abrupt control movement without overstressing the airframe.

Marker Beacon — Low-powered transmitter that directs its signal upward in a small, fan-shaped pattern that’s used along the flight path when approaching an airport for landing.

Mayday — International radio distress signal, usually repeated three times to indicate imminent and grave danger and that immediate assistance is requested.

Mean Aerodynamic Chord (MAC) — Average distance from the leading edge to the trailing edge of the wing.

Mean Sea Level (MSL) — Average height of the surface of the sea for all stages of tide.

METeorological Aerodrome Report (METAR) —

Minimum Equipment List (MEL) — List developed for larger aircraft that outlines equipment that can be inoperative for

various types of flight including IFR and icing conditions.

Missed Approach — Flight maneuver conducted by a pilot when an instrument approach cannot be completed to a landing.

Mode C — Altitude reporting transponder mode.

Monocoque — Shell-like fuselage design in which the stressed outer skin is used to support the majority of imposed

stresses.

Monoplanes — Airplanes with a single set of wings.

Multicom — Frequency (122.9 MHz) for pilots to use as a common traffic advisory frequency to self-announce

their position and intentions at airports that don’t have a tower, an FSS, or a UNICOM.

N

Nacelle — Streamlined enclosure on an aircraft in which an engine is mounted.

Narrow-body Aircraft —

Nondirectional Radio Beacon (NDB) — Ground-based radio transmitter that transmits radio energy in all directions.

Non-precision Approach — Standard instrument approach procedure in which only horizontal guidance is provided.

Notice to Airmen (NOTAM) — Notice containing time-critical information which is either of a temporary nature or is not known far enough in advance to permit publication on aeronautical charts or other operational publications.

O

Obstruction Light — Light, or one of a group of lights, usually red or white, mounted on a surface structure or natural terrain to warn pilots of the presence of a flight hazard.

Overshoot —

P

Pan Pan —

Parasite Drag — Part of total drag created by the form or shape of airplane parts.

Payload —

P-factor — Tendency for an aircraft to yaw to the left due to the descending propeller blade on the right producing more

thrust than the ascending blade on the left.

Pilot in Command (PIC) — Pilot responsible for the operation and safety of an aircraft.

Pilot Weather Report (PIREP) — A report, generated by pilots, concerning meteorological phenomena encountered in flight.

Pilotage — Navigation by visual landmarks.

Planform — Shape or form of a wing as viewed from above.

Powerplant — Complete engine and propeller combination with accessories.

Precision Approach — Standard instrument approach procedure in which both vertical and horizontal guidance is provided.

Precision Approach Path Indicator (PAPI) — Landing guidance system consisting of one row two or four lights.

Preignition — Occurs when the fuel/air mixture is ignited in advance of the normal timed ignition and is usually caused by a residual hotspot in the cylinder.

Pressure Altitude — Height above the standard pressure level of 29.92 in. Hg. Obtained by setting 29.92 in the barometric pressure window and reading the altimeter.

Prevailing Visibility — Greatest horizontal visibility throughout at least half the horizon.

Primary Flight Display (PFD) — Display that provides increased situational awareness to the pilot by replacing the traditional six instruments used for instrument flight with an easy-to-scan display that provides the horizon, airspeed, altitude, vertical speed, trend, trim, and rate of turn among other key relevant indications.

Progressive Taxi — Precise taxi instructions issued to a pilot unfamiliar with an airport, usually issued in stages as the aircraft proceeds along the route.

Procedure Turn — A maneuver prescribed when it is necessary to reverse direction to establish an aircraft on the intermediate approach segment or final approach course.

Pushback —

Q

Q Codes — Three-letter codes starting with the letter Q that are used in radio communication to request and transmit information.

Quick Access Recorder (QAR) — Airborne flight recorder designed to provide quick and easy access to raw flight data.

R

Radar Altimeter (also called Radio Altimeter) — Electronic altimeter that determines the height of an aircraft above the terrain by measuring the time needed for a pulse of radio-frequency energy to travel from the aircraft to the ground and return.

Radar Contact — Term used by ATC to advise a pilot that the aircraft is identified on radar.

Radar Vector — Heading issued by a radar controller to the pilot of an aircraft to provide navigational guidance.

Radial — Navigational signal generated by a VOR or VORTAC, measured as a magnetic bearing from the station.

Ram Air Turbine (RAM) — Near instantaneous loss of cabin pressure in aircraft with a pressurized cockpit or cabin.

Rapid Decompression — Near instantaneous loss of cabin pressure in aircraft with a pressurized cockpit or cabin.

Relative Wind — Airflow opposite and parallel to flight path, generated by the movement of an airfoil through the air.

Reverse Thrust — Aircraft system that temporarily redirects the engine thrust forward, typcially upon landing, helping in deceleration on the runway.

Roll — Rotational movement of an aircraft around its longitudinal axis, controlled by ailerons.

Rudder — Primary control surface on the tail of an aircraft used to control its yaw, typically controlled by pedals in the cockpit.

Runway — Defined rectangular strip of paved or unpaved surface on an airport used for aircraft takeoffs and landings.

Runway Visual Range (RVR) — Instrumentally derived value representing the horizontal distance a pilot in a moving aircraft should see down the runway.

S

Second in Command (SIC) — Pilot who sits on the right seat of a cockpit, often referred to as the first officer or copilot, serving to assist the captain in flying the aircraft.

Sectional Chart — Aeronautical chart that covers 6° to 8° of longitude and approximately 4° of latitude and is given the name of a primary city within its coverage.

Segmented Circle — Set of visual indicators which provide traffic pattern information at airports without operating control towers.

Service Ceiling — Density altitude where an aircraft cannot climb at a rate greater than a specified value, typically 100 feet per minute.

Servo Tab — Auxiliary control mounted on a primary control surface, which automatically moves in the direction opposite the primary control to provide an aerodynamic assist in the movement of the control.

Sideslip — Flight maneuver frequently used in crosswind landings, achieved through opposite aileron and rudder input, causing the aircraft to move sideways while the nose points in the direction of flight.

Significant Meteorological Information (SIGMET) — Weather advisory in abbreviated plain language concerning the occurrence or expected occurrence of potentially hazardous en route weather phenomena that may affect the safety of aircraft operations.

Seniority — Ranking based on a pilot’s date of hire within an airline, influencing schedule preferences, promotions, and other privileges.

Skid — Flight condition in which the rate of turn is too fast for the angle of bank and the nose points to the inside of the turn.

Slant Range — Horizontal distance between an aircraft and a ground-based station, typically measured along the line of sight.

Slats — Extendable, high-lift devices on the leading edge of the wings that increase lift during low speed operations such as takeoff and landing.

Slip — Flight condition in which the rate of turn is too slow for the angle of bank and the nose points to the outside of the turn.

Somatogravic Illusion — Misperception of being in a nose-up or nose-down attitude, induced by rapid acceleration or deceleration in flight situations lacking visual reference.

Special Flight Permit (also known as Ferry Permit) — Flight permit issued to an aircraft that does not meet airworthiness requirements but is capable of safe flight.

Spin — Aggravated stall that causes autorotation about the spin axis and a downward corkscrew path.

Spoilers — Panels that, when extended, reduce lift and increase drag by disrupting (or spoiling) the smooth airflow over the wing surface.

Squawk — Aviation term used by air traffic controllers to assign a transponder code to an aircraft or by pilots to report the assigned code, commonly referred to as the squawk code.

Stabilator — Single-piece horizontal tail surface on an airplane that serves the purposes of both the horizontal stabilizer and the elevator.

Stall — Rapid decrease in lift caused by the separation of airflow from the wing’s surface brought on by exceeding the critical angle of attack.

Standard Holding Pattern — Holding pattern in which all turns are made to the right

Standard Rate Turn — Turn in which an aircraft changes its direction at a rate of 3° per second (360° in 2 minutes) for low- or medium-speed aircraft.

St. Elmo’s Fire — Luminous electrical discharge that appears as blue or violet glow around parts of an aircraft, caused by the ionization of air molecules and typically encountered during thunderstorms.

Steep Turn — Flight maneuver in which an aircraft turns greater than the standard rate in instrument flight or a 45° bank in visual flight.

Stopway — Designated area beyond the takeoff runway, identified by large yellow chevrons, intended for aircraft deceleration during an aborted takeoff.

Straight-and-Level Flight — Flight in which a constant heading and altitude are maintained.

T

Tailwind — Wind blowing in the same direction as the aircraft’s flight path.

Taxiway — Designated path on an airport surface that connects runways with terminals, hangars, and other facilities.

Tetrahedron — Large, triangular-shaped, kite-like object mounted on a pivot that’s installed near runways to indicate wind direction.

Threshold — Beginning of the landing area of the runway.

Throttle — Control unit, often in the form of a lever or knob, that controls the power output of an aircraft engine.

Thrust — Forward force that propels the airplane through the air.

Touch and Go — Maneuver in which an aircraft lands on a runway, briefly touches down, and then takes off again without coming to a full stop.

Track — Flight path of an aircraft over the ground.

Tracking — Flying a heading that will maintain the desired track to or from the station regardless of crosswind conditions.

Traffic Pattern — Traffic flow that is prescribed for aircraft landing and taking off from an airport.

Trailing Edge — Rear edge of an airfoil, particularly a wing, where the airflow above and below the wing rejoins after being separated at the leading edge

Transponder — Electronic device aboard the airplane that enhances an aircraft’s identity on an ATC radar screen.

Transponder Code (also known as Squawk Code) — One of 4,096 four-digit discrete codes ATC assigns to distinguish between aircraft.

Tricycle Gear — Two main wheels located on either side of the fuselage and a third wheel, the nosewheel, positioned on the nose of the airplane.

Trim Tab — Small auxiliary hinged portion of a movable control surface that can be adjusted during flight to a position.

True Airspeed (TAS) — Speed at which an aircraft is moving relative to the surrounding air.

True Altitude — Height or vertical distance of an aircraft above mean sea level.

Truss — Fuselage design made up of supporting structural members that resist deformation by applied loads.

T-tail — Empennage design in which the horizontal stabilizer is mounted on the top of the vertical stabilizer, forming a T.

Turbulence — Irregular and chaotic airflow that causes variations in airspeed, altitude, and attitude.

Turn-and-slip Indicator — Flight instrument that indicates the rate of turn and the slip or skid of the turn through a curved glass inclinometer.

Turn Coordinator — Flight instrument that displays the rate and quality of turn, largely replacing the turn-and-slip indicator in modern aircraft.

U

Ultimate Load Factor — Load that causes physical breakdown in an aircraft or aircraft component during a strength test, or the load that according to computations, should cause such a breakdown.

Unable — Inability to comply with a specific instruction, request, or clearance

Uncontrolled Airspace — Airspace designated as Class G airspace within which air traffic control has no authority or responsibility to control air traffic.

UNICOM (Universal Communications) — Nongovernment air-ground radio communication station that provides information (and sometimes services) at certain airports where there is no tower or FSS.

Upwind Leg — Portion of the traffic pattern that’s offset and parallel to the landing runway and in the same direction as the landing aircraft.

Useful Load — Weight of the crew, passengers, baggage, usable fuel, and drainable oil.

V

V Speeds — Significant operating speeds for specific aircraft with each denoting a reference, optimum, or limitation to enhance safety and performance.

Vapor Lock — Complete or partial interruption of fuel flow due to vaporization inside the fuel delivering system.

Variation — Angular difference between true and magnetic north, shown on aeronautical charts by isogonic lines.

Vertical Speed Indicator (VSI) — Flight instrument that displays the rate of climb or descent by sensing the rate of pressure change due to differences in altitude.

Very-high Frequency Omnidirectional Range (VOR) — Ground-based radio system that provides navigational guidance to pilots by enabling instruments to determine aircraft relative location.

Victor Airway — Low altitude air route based on straight lines between VORs or VOR intersections.

Visual Approach Slope Indicator (VASI) — System of white and red lights arranged to provide descent guidance information during the approach to the runway.

Visual Flight Rules (VFR) — Regulations governing flight planning and operation under Visual Meteorological Conditions (VMC).

Visual Meteorological Conditions (VMC) — Meteorological conditions expressed in terms of visibility, distance from cloud, and ceiling equal or better than specified minima that permit visual flight.

W

Wake Turbulence — Disturbance in the air behind an aircraft in flight caused primarily by wingtip vortices and jet wash.

Waypoint — Designated geographical position defined by GPS coordinates, navigational aids, or landmarks, which is used for route planning and reporting.

Wide-body Aircraft — Large airliners with adequate cabin width to fit two passenger aisles.

Wind Shear — Sudden shift in wind speed, direction, or both over a short distance.

Windsock — Cone or sock-like cloth tube mounted on a pole at airports to indicate wind direction and speed.

Winglets — Vertical extensions at the wingtips designed to reduce the drag caused by wingtip vortices, and therefore, improve fuel efficiency and enhance aircraft performance.

Wingspan — Distance from wingtip to wingtip.

Wingtip Vortices — Swirling air masses that form as a byproduct of lift generation and trail off the tip of a wing during flight.

Y

Yaw — Aircraft rotation around its vertical axis, or simply the left and right movement of the nose.

Yoke — Control wheel or column used to maneuver aircraft, or more precisely, to control pitch and roll. It can also incorporate other functions through buttons.

Z