Find aviation terms starting with the letter:
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 the terminology from basic words to complex concepts.
I’ve put together an extensive selection of aircraft, pilot, and airline terminology, providing you with a thorough and reliable resource. I regularly add and revise terms to maintain this glossary’s relevance and accuracy.
A
Abeam — A term used by pilots or air traffic controllers to refer to when a point, fix, or object is approximately 90 degrees to the left or right of aircraft track.
Aborted Takeoff (also known as Rejected Takeoff) — A procedure where the pilot discontinues the takeoff after starting the roll but before reaching V1 (takeoff decision speed).
Absolute Altitude — The actual height above the surface of the earth or Above Ground Level (AGL).
Absolute Ceiling — The highest altitude at which an aircraft can maintain level flight.
Acceleration Error — A 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.
Acknowledge — A radio communication request for the recipient to confirm they have received and understood a message or instruction.
Adverse Yaw — A 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 — A defined area on land or water intended for the arrival, departure, and surface movement of aircraft.
Aeronautical Chart — A type of map used in air navigation that contains topographic features, hazards and obstructions, navigation aids, navigation routes, designated airspace, and airports.
Affirmative — Yes.
Ailerons — Primary flight control surfaces that control roll and are mounted on the trailing edge of an airplane wing near the tip.
Airfoil — Any surface, such as a wing, propeller, or rudder, which provides aerodynamic force when it interacts with a moving stream of air.
Airplane — An engine-driven, fixed-wing, heavier-than-air aircraft that is supported in flight by the dynamic reaction of the air against its wings.
Airspace — The air available to aircraft to fly in, especially the part subject to the jurisdiction of a particular country.
Airspeed Indicator — A differential pressure gauge that displays airspeed, typically in knots, by measuring the dynamic pressure of the air through which the aircraft is flying.
Airway — A 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 — A certificate issued by the appropriate aviation authority to attest that an aircraft is in a condition for safe operation.
Altimeter — A flight instrument that indicates altitude by sensing pressure changes.
Altimeter Setting — A barometric pressure setting used to adjust a pressure altimeter for variations in atmospheric pressure and temperature.
Angle of Attack — The angle between the airfoil’s chord line and the relative wind.
Angle of Incidence — The angle between the chord line of the wing and the longitudinal axis of the airplane.
Anhedral — The downward slant from root to tip of an aircraft’s wing or horizontal tail surface.
Apron (commonly referred to as Ramp in the US) — A defined area in an airport intended to accommodate aircraft for purposes of loading or unloading passengers or cargo, refueling, parking, or maintenance.
Aspect Ratio — The span of a wing divided by its average chord.
Asymmetric Thrust (also known as P Factor) — The 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 — A flight instrument that reflects the airplane’s attitude in relation to the horizon.
Autopilot — The automatic flight control system that keeps an aircraft in level flight or on a set course through pilot or navigation station guidance.
Aviation Alphabet — A standardized set of words used to spell out letters in radio communication.
B
Barber Pole — The red and white striped needle on an airspeed indicator that indicates the maximum operating speed or Mach number.
Base Leg — A 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 — The standard empty weight plus optional and special equipment that has been installed.
Bearing — The 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°.
Biplane — An airplane with two sets of wings.
Black box (though bright orange for easier recovery) — A 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.
Blade Angle — The angle between the reference line of a propeller blade and a plane perpendicular to the axis of rotation.
Blast Pad — A surface adjacent to the ends of a runway provided to reduce the erosive effect of jet blast and propeller wash
Bleed Air — The 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 — A block of altitudes assigned by ATC to allow altitude deviations.
Bracketing — A navigation technique that involves making adjustments for wind drift to maintain a desired course.
C
Cabin Altitude — The cabin pressure in terms of equivalent altitude above sea level.
Calibrated Airspeed — The indicated airspeed of an aircraft, corrected for installation and instrument errors.
Camber — The curve of an airfoil section from the leading edge to the trailing edge.
Canard — A horizontal surface mounted ahead of the main wing to provide longitudinal stability and control.
Ceiling — The 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 — The point where the entire weight of the airplane is considered to be concentrated.
Center of Pressure — The point along the wing chord line where lift is considered to be concentrated.
Changeover Point — The point along the route or airway segment between two adjacent navigation facilities or waypoints where changeover in navigation guidance should occur.
Checklist — A systematic and sequential list of items that must be performed to properly accomplish a task.
Chord Line — An imaginary straight line between the leading and trailing edges of an airfoil section.
Clean Configuration — The onfiguration in which all flight control surfaces have been placed to create minimum drag.
Clearance — An ATC permission for an aircraft to proceed under specified traffic conditions within controlled airspace.
Clear Air Turbulence — A 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 — A defined rectangular area beyond the end of a runway cleared or suitable for use in lieu of runway to satisfy takeoff distance requirements.
Codeshare — A business arrangement between airlines where they share and market the same flight under their own airline codes.
Complex Aircraft — Aircraft with retractable landing gear, flaps, and a controllable-pitch propeller.
Compressor Stall — A 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 — The Inverted cone-shaped area above a VOR station where no signal is received, causing erroneous indications.
Configuration — The position of the landing gear and flaps or layout of aircraft interior space and seating.
Contrail (short for condensation trail) — A 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.
Controlled Airport — An 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) — A 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 — The intended or desired direction of flight in the horizontal plane measured in degrees from true or magnetic north.
Cowl Flaps — A 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 crosswind drift by offsetting the aircraft’s heading, so the combined effect of aircraft velocity and wind keeps the aircraft on the desired track.
Critical Altitude — The maximum altitude under standard atmospheric conditions at which a turbocharged engine can produce its rated horsepower.
Critical Angle of Attack — The angle of attack at which a wing stalls regardless of airspeed, flight attitude, or weight.
Crosswind — The wind that’s not parallel to a runway or the path of an aircraft.
D
Deadhead — A crew member traveling as a passenger to reposition for their next flight.
Dead Reckoning — A navigation method used to estimate a position by calculating based on previously known positions, time, speed, distance, and direction.
Deceleration Error — A 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.
Decompression — The failure of the aircraft pressurization system to maintain the designated cabin pressure, which often occurs from system malfunction 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 — A compass error caused by magnetic disturbances from electrical and metal components in the airplane.
Dihedral — The upward angle formed between the wings of an aircraft and the horizontal axis.
Displaced Threshold — The 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 — 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 — A flight track that is a constant distance from the station or waypoint.
Downwind Leg — A 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 — The aerodynamic force that opposes thrust and relative motion of aircraft through the air.
Drift Angle — The angle between heading and track.
Dry Lease — A type of lease in which the aircraft is provided with no crew and maintenance guarantees.
Dutch Roll — The combined rolling and yawing motion in an aircraft, typically occurring when dihedral effects overpower directional stability.
E
Elevation — The height of a ground feature, obstacle, or station above mean sea level (MSL).
Elevator — A horizontal, movable primary control surface in the tail section, or empennage, of an airplane.
Emergency Evacuation — A rapid and urgent disembarkation of an aircraft by passengers and crew using all available exits due to an immediate threat to safety.
Emergency Landing — The unplanned landing made by an aircraft due to an urgent situation such as mechanical failure, medical emergency, or adverse weather conditions.
Emergency Locator Transmitter — An 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.
Empennage — The section of the airplane which consists of the vertical stabilizer, the horizontal stabilizer, and the associated control surfaces.
Endurance — The amount of time an aircraft can remain airborne with a given amount of fuel under specific conditions.
Exit Row — The row of seats where passengers are seated next to emergency exits and are responsible for assisting with their operation during an evacuation.
F
False Horizon — An 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) — A 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) — The last leg in an aircraft’s approach to landing, when the aircraft is lined up with the runway and descending for landing.
First Officer (also known as co-pilot or second-in-command) — A 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 — A specific geographic location identified through visual reference, radio navigational aids (NAVAIDs), celestial navigation, or other navigational methods.
Fixed-Base Operator — A 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 — A propeller with fixed blade angles.
Flameout — A 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 — A maneuver during landing where the pilot raises the aircraft’s nose to reduce descent rate and ensure a safe touchdown.
Flight Deck — The forward compartment, or cockpit, of a large airplane that houses pilot seats, aircraft instruments, and flight controls.
Flight Director — An aircraft system that provides real-time pitch and roll guidance, enabling the autopilot or pilot to maintain a desired flight path.
Flight Level — 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 — An 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 — A line, course, or track along which an aircraft is flying or is intended to be flown.
Flight Plan — A document prepared by a pilot or flight dispatcher before departure, outlining the intended route, altitude, speed, and other relevant information.
Flight Service Station — An 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 — 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 — The controlled jettison of fuel during flight to reduce an aircraft’s weight for safe landing.
Fuselage — The main part of an airplane that houses the cockpit, cabin, and cargo holds and provides attachment points for other major airplane components.
G
George — A nickname for the autopilot system, possibly a reference to King George VI or George De Beeson.
Glass Cockpit — A 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 — The descent profile determined for vertical guidance during a final approach.
Glider — A lightweight airplane designed to fly without an engine, using rising air currents like thermals or ridge lift to stay airborne
Glide Slope — The part of the Instrument Landing System (ILS) that provides vertical guidance to aircraft on the final approach course.
Go Around — A 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 — An 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 phenomenon where increased lift and reduced drag are experienced by an aircraft when it’s close to the ground, caused by the interaction of airflow between the wings and the surface.
Ground Power Unit — A stationary or mobile device that supplies electrical power to an aircraft on the ground, allowing the aircraft systems to operate without using the engines or APU.
Ground Speed — The speed of the aircraft in relation to the ground.
Gyroplane — A type of rotorcraft that uses an unpowered rotor for lift and a propeller, commonly rear-mounted, for thrust.
H
Heading — The direction in which the aircraft’s nose points, expressed in degrees from north.
Heading Indicator (also called Direction Gyro) — An aircraft instrument that uses a gyroscope to display the aircraft’s heading on a 360-degree azimuth scale, usually omitting the final zero.
Head-up Display — Aircraft system that projects crucial flight information onto a transparent screen directly in the pilot’s line of sight, enabling monitoring of key data while maintaining focus on the forward field of vision.
Headwind — The wind that blows opposite to the direction of aircraft movement.
Heavy — A wake turbulence category for aircraft with a maximum takeoff weight of 300,000 pounds (136,000 kilograms) or more.
High-Performance Airplane — An airplane with an engine of more than 200 horsepower.
Holding — A maneuver in which an aircraft follows a specified flight path, or holding pattern, for purposes such as awaiting landing clearance, handling an emergency, or losing altitude.
Holding Pattern — A racetrack-like flight path that aircraft follow to stay within a specific area while waiting for landing clearance or during air traffic delays.
Homing — A navigation method where an aircraft flies directly toward a Non-Directional Beacon (NDB) by maintaining a zero relative bearing to the beacon.
Horizontal Stabilizer — A horizontal tail component, often fixed but sometimes adjustable or variable-sweep, that maintains longitudinal stability by restoring the aircraft nose to a level attitude after pitching up or down.
Hot Start — An engine start where normal engine rotation occurs, but the exhaust temperature exceeds prescribed limits, often due to an excessively rich fuel mixture in the combustor.
Hung Start — An engine start where the engine lights off but fails to accelerate to its idle RPM, typically because of inadequate power from the starter.
Hydroplaning — A phenomenon where aircraft tires lose contact with the runway surface due to water, slush, or snow that is deeper than the tire tread depth, reducing the effectiveness of braking and steering.
Hyperventilation — Rapid, deep breathing, often triggered by anxiety or panic, that lowers blood carbon dioxide levels and leads to symptoms like dizziness, shortness of breath, and tingling in the hands or feet.
Hypoxia — Oxygen deficiency in the body, usually due to reduced oxygen levels at high altitudes or cabin depressurization, leading to impaired physiological functions.
I
Ident — A request made by air traffic control for a pilot to activate the transponder’s identification feature, temporarily highlighting its signal on the controller’s radar screen.
Indicated Airspeed — The speed of an aircraft displayed on the airspeed indicator as measured by its pitot-static system.
Indicated Altitude — The altitude displayed on the altimeter, which measures the aircraft’s height based on the outside atmospheric pressure.
Induced Drag — A type of drag that occurs due to lift generation, increasing with a higher angle of attack and decreasing airspeed.
Inertial navigation system — A navigation system that uses accelerometers, gyroscopes, and a computer to continuously track the position, orientation, and velocity of an aircraft without relying on external references.
Instrument Flight Rules — A set of regulations governing aircraft operations where pilots rely on instruments for navigation and flight management, under instrument or visual meteorological conditions.
Instrument Meteorological Conditions — Meteorological conditions that require pilots to fly using instruments and under IFR, typically characterized by low visibility, heavy rain, and widespread fog.
Instrument landing system — An electronic system that provides both horizontal and vertical guidance to aircraft approaching a specific runway, facilitating precision instrument landing procedures.
Interference Drag — The component of parasite drag generated from the mixing of airflow streams between airframe parts, such as the wing and fuselage.
Isogonic Lines — Lines that connect points of equal magnetic variation on navigation charts.
J
Jeppesen Charts — Aeronautical charts used by pilots worldwide for flight planning and navigation, known for their quality, accuracy, and up-to-date information.
Jet Blast — A rapid stream of exhaust gases expelled from the engines of a jet aircraft at high power settings, particularly before or during takeoff.
Jet Bridge (also called Jetway) — A movable connector that links an airport terminal gate to an aircraft, allowing passengers to board and disembark without needing to go outside.
Jet Lag — A temporary sleep disorder that occurs when traveling quickly across multiple time zones, disrupting the internal body clock and typically resulting in fatigue, impaired cognitive abilities, and sleep disturbances.
Jet Stream — A fast, narrow air current flowing from west to east, found near the tropopause (most commonly between 30,000 and 40,000 feet), moving at 110 mph on average but can reach speeds of more than 250 mph.
Jet Wash — The turbulent airflow created by the forceful expulsion of exhaust gases from a jet engine.
Jumbo Jet — A colloquial term for huge wide-body airliners capable of carrying hundreds of passengers over long distances, most commonly associated with the Boeing 747.
Jump Pilot — A pilot who flies an airplane that skydivers use for their jumps, typically operating at altitudes between 10,000 to 14,000 feet.
Jump Seat — An extra aircraft seat in the cockpit or cabin, typically reserved for crew members and often used during takeoff and landing.
K
Kneeboard — A clipboard used by pilots to hold tablets, charts, checklists, and other important documents.
Knot — A unit of speed equivalent to one nautical mile per hour, exactly 6076 feet (1,852 meters), or approximately 1.151 statute miles per hour.
Kollsman Window — A small adjustable window on an aircraft’s altimeter that allows pilots to set the current barometric pressure for accurate altitude readings.
L
Landing Gear — The undercarriage of an aircraft that supports it on the ground or water, typically using wheels but can feature floats or skis on some airplanes.
Lateral Axis — An imaginary line that runs from wingtip to wingtip, around which the aircraft rotates during pitch.
Lapse Rate — The rate at which temperature decreases with altitude in the atmosphere.
Layover — A scheduled stop between connecting flights, typically lasting less than four hours for domestic flights and less than 24 hours for international flights.
Leading Edge — The front edge of an airfoil that first contacts the air as the aircraft moves forward.
Lift — The upward force created by the effect of airflow as it passes over and under the wing.
Light-Sport Aircraft — A category of small, recreational aircraft that must adhere to regulatory limits, including maximum weight, seating capacity, and speed.
Line Up And Wait — A phrase used by ATC to instruct the pilot to position the aircraft on the runway and wait until they receive takeoff clearance.
Load Factor — The ratio of the load supported by the airplane’s wings to the weight of the aircraft and its contents.
Load Sheet (also called Load and Trim Sheet) — A critical document that provides detailed information about the weight and balance to ensure the aircraft is loaded correctly and within safe weight and balance limits.
Localizer — The portion of an ILS that gives left/right guidance information down the centerline of the instrument runway for final approach.
Logbook — A record used to document flight hours, maintenance, and other important details about an aircraft’s operations or a pilot’s flight experience.
Longitudinal Axis — An imaginary line running from the nose to the tail, around which the aircraft rotates during roll.
M
Mach Number — The ratio of the true airspeed of the aircraft to the speed of sound in the same atmospheric conditions, named in honor of physicist Ernst Mach.
Magnetic Bearing — The direction to or from a station measured relative to magnetic north and expressed in degrees from 0 to 360.
Magneto — An engine-driven generator that produces high-voltage electrical current for the spark plugs in an aircraft engine.
Maintain — An ATC term used to instruct pilots to keep or continue a certain flight parameter or condition, such as altitude, heading, or speed.
Maneuvering Speed — The maximum speed at which you can use full, abrupt control movement without overstressing the airframe.
Marker Beacon — A radio navigation aid that provides pilots with visual and audio cues in the cockpit, indicating specific points along an instrument approach path.
Mayday — The international radiotelephony distress signal, usually repeated three times to indicate imminent and grave danger and that immediate assistance is requested.
Mean Sea Level — The average height of the sea surface, used as a reference point for measuring altitude in aviation.
Meteorological Aerodrome Report — A standardized aviation weather report issued at regular intervals (typically every hour), providing data about the weather conditions at an airport.
Minimum Equipment List — A list of aircraft systems and components that can be inoperative under specific conditions, ensuring safe operation despite certain equipment failures.
Missed Approach — A flight maneuver in which the pilot aborts the landing during an instrument approach and follows a predefined procedure to ensure safe navigation and separation.
Mode C — The transponder mode that provides altitude information to air traffic control, facilitating accurate radar tracking and ensuring safe aircraft separation.
Monocoque — A shell-like fuselage design in which the stressed outer skin is used to support the majority of imposed stresses.
Monoplane — An airplane with a single set of wings.
Multicom — A frequency (122.9 MHz) for pilots to use as a common traffic advisory frequency to self-announce their position and intentions at uncontrolled airports.
N
Nacelle — A streamlined container for aircraft parts such as engines, fuel or equipment.
Narrow-body Aircraft — An airplane with a single aisle in the passenger cabin, typically accommodating 2 to 6 seats per row.
Navigational Aid — Visual indicators or electronic systems, either airborne or on the ground, that provide navigational guidance or position information to aircraft.
Nondirectional Radio Beacon — A ground-based radio transmitter that transmits radio energy in all directions.
Non-precision Approach — A standard instrument approach procedure in which only horizontal guidance is provided.
Notice to Airmen — A notice containing time-critical information that is temporary or not available in time for publication on charts or operational publications.
O
Obstruction Light — A 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 — Exceed a planned flight path, altitude, or speed, most commonly during landing approaches.
P
Pan Pan — The international radiotelephony urgency signal, typically repeated three times to indicate uncertainty or alert followed by the nature of the urgency.
Parasite Drag — The part of total drag created by the form or shape of airplane parts.
Payload — The weight of passengers, cargo, and fuel an aircraft carries, excluding its own weight.
P-factor — The 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 — The pilot responsible for the operation and safety of an aircraft.
Pilot Weather Report — A pilot-generated report concerning meteorological phenomena encountered in flight.
Pilotage — Navigation by visual landmarks.
Planform — The shape or form of a wing as viewed from above.
Powerplant — The complete propulsion system of an aircraft, including the engine and all supporting components like the fuel, ignition, and cooling systems.
Precision Approach — A standard instrument approach procedure in which both vertical and horizontal guidance are provided.
Precision Approach Path Indicator — A landing guidance system consisting of one row of two or four lights.
Preignition — A condition that occurs when the fuel/air mixture is ignited in advance of the normal timed ignition, usually caused by a residual hotspot in the cylinder.
Pressure Altitude — The 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.
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 required to reverse direction and align an aircraft with the intermediate approach segment or final approach course.
Pushback — An airport procedure in which an aircraft is moved backward away from its parking stand or gate using a specialized ground vehicle, commonly known as a pushback tug.
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 — An airborne flight recorder designed to provide quick and easy access to raw flight data.
R
Radar Contact — A term used by ATC to advise a pilot that the aircraft is identified on radar.
Radar Vector — A heading issued by a radar controller to the pilot of an aircraft to provide navigational guidance.
Radial — A navigational signal generated by a VOR or VORTAC, measured as a magnetic bearing from the station.
Radio Altimeter (also called Radar Altimeter) — An 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.
Ram Air Turbine — An emergency, wind-driven propeller deployed into the external airflow to provide backup hydraulic or electrical energy for an aircraft experiencing a total power failure.
Rapid Decompression — A near instantaneous loss of cabin pressure in aircraft with a pressurized cockpit or cabin.
Relative Wind — The airflow opposite and parallel to the flight path, generated by the movement of an airfoil through the air.
Reverse Thrust — An aircraft system that temporarily redirects engine thrust forward, typically upon landing to help in deceleration on the runway.
Roll — The rotational movement of an aircraft around its longitudinal axis, controlled by ailerons.
Rudder — A primary control surface on the tail of an aircraft used to control its yaw, typically controlled by pedals in the cockpit.
Runway — A defined rectangular strip of paved or unpaved surface on an airport used for aircraft takeoffs and landings.
Runway Visual Range — Instrumentally derived value representing the horizontal distance a pilot in a moving aircraft should see down the runway.
S
Second in Command — The pilot who sits in 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 — An 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 — A set of visual indicators which provide traffic pattern information at airports without operating control towers.
Service Ceiling — The density altitude where an aircraft cannot climb at a rate greater than a specified value, typically 100 feet per minute.
Servo Tab — The 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 — A 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 — A 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 — A ranking based on a pilot’s date of hire within an airline, influencing schedule preferences, promotions, and other privileges.
Skid — A 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 — The 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 — A 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 — An illusion 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) — A flight permit issued to an aircraft that does not meet airworthiness requirements but is capable of safe flight.
Spin — An 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 — An 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 — A single-piece horizontal tail surface on an airplane that serves the purposes of both the horizontal stabilizer and the elevator.
Stall — A 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 Rate Turn — A 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 — A luminous electrical discharge that appears as a blue or violet glow around parts of an aircraft, caused by the ionization of air molecules and typically encountered during thunderstorms.
Steep Turn — A flight maneuver in which an aircraft turns at a greater rate than the standard rate in instrument flight or a 45° bank in visual flight.
Stopway — A designated area beyond the takeoff runway, identified by large yellow chevrons, intended for aircraft deceleration during an aborted takeoff.
T
Tailwind — The wind blowing in the same direction as the aircraft’s flight path.
Taxiway — A designated path on an airport surface that connects runways with terminals, hangars, and other facilities.
Tetrahedron — A large, triangular-shaped, kite-like object mounted on a pivot that’s installed near runways to indicate wind direction.
Threshold — The beginning of the landing area on the runway.
Throttle — A control unit, often in the form of a lever or knob, that controls the power output of an aircraft engine.
Thrust — The forward force that propels the airplane through the air.
Touch and Go — A maneuver in which an aircraft lands on a runway, briefly touches down, and then takes off again without coming to a full stop.
Track — The 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 — The traffic flow that is prescribed for aircraft landing and taking off from an airport.
Trailing Edge — The 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 — An 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 — A type of landing gear with two main wheels attached to the fuselage and a nosewheel at the front of the aircraft.
Trim Tab — a small auxiliary hinged portion of a movable control surface that can be adjusted during flight to a position.
True Airspeed — The speed at which an aircraft is moving relative to the surrounding air.
True Altitude — The height or vertical distance of an aircraft above mean sea level.
Truss — A fuselage design made up of supporting structural members that resist deformation by applied loads.
T-tail — An 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 — A flight instrument that indicates the rate of turn and the slip or skid of the turn through a curved glass inclinometer.
Turn Coordinator — A flight instrument that displays the rate and quality of turn, largely replacing the turn-and-slip indicator in modern aircraft.
U
Ultimate Load Factor — The load that causes physical breakdown in an aircraft or aircraft component during a strength test or according to computations.
Unable — A radio term to convey the 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.
Universal Communications — A nongovernment air-ground radio communication station that provides information (and sometimes services) at certain airports where there is no tower or FSS.
Upwind Leg — The 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 — The 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 — The complete or partial interruption of fuel flow due to vaporization inside the fuel delivering system.
Variation — The angular difference between true and magnetic north, shown on aeronautical charts by isogonic lines.
Vertical Speed Indicator — A 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 — A ground-based radio system that provides navigational guidance to pilots by enabling instruments to determine aircraft relative location.
Victor Airway — A low altitude air route based on straight lines between VORs or VOR intersections.
Visual Approach Slope Indicator — A system of white and red lights arranged to provide descent guidance information during the approach to the runway.
Visual Flight Rules — Regulations governing flight planning and operation under Visual Meteorological Conditions (VMC).
Visual Meteorological Conditions — 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 — A disturbance in the air behind an aircraft in flight caused primarily by wingtip vortices and jet wash.
Waypoint — A designated geographical position defined by GPS coordinates, navigational aids, or landmarks, which is used for route planning and reporting.
Wide-body Aircraft — A large airliner with two aisles, typically seating 7 to 10 passengers per row.
Wind Shear — The sudden shift in wind speed, direction, or both over a short distance.
Windsock — A 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 — The distance from wingtip to wingtip.
Wingtip Vortices — Swirling air currents that form as a byproduct of lift generation and trail off the tip of a wing during flight.
Y
Yaw — The aircraft rotation around its vertical axis, or simply the left and right movement of the nose.
Yoke — A control wheel or column used to maneuver an aircraft, or more precisely, to control pitch and roll. It can also incorporate other functions through buttons.
Z
Zulu Time — An aviation term for Coordinated Universal Time (UTC), a standard time reference used for timekeeping and to prevent confusion due to different time zones.
