Glossary

Aviation terms, explained simply

A growing dictionary of 322+ flying terms — from fare classes to technical aviation jargon — explained in plain English.

A B C D E F G H I J K L M N O P Q R S T U V W

A 32 terms

Alliance (Airline Alliance): A partnership between airlines (such as Star Alliance, Oneworld, or SkyTeam) that lets passengers earn and redeem miles, and connect more easily across partner carriers.
A Check: A light, routine maintenance inspection performed on an aircraft at relatively short, frequent intervals.
ACARS: A digital datalink system used to send short text messages between an aircraft and ground stations, such as operational or maintenance data.
ADS-B: Automatic Dependent Surveillance–Broadcast — a system where aircraft broadcast their GPS position so it can be tracked by ATC and other aircraft.
Aerodrome: The formal ICAO term for any defined area on land or water, including buildings and equipment, used for aircraft arrival, departure, and ground movement.
Affirm: Radio phraseology meaning "yes," used by pilots and controllers to avoid confusion over a simple "yes" on noisy channels.
AGL (Above Ground Level): The height of an aircraft or object measured directly from the terrain below it, as opposed to height measured from sea level.
Aileron: A hinged control surface on the outer trailing edge of each wing that controls roll by moving in opposite directions.
AIM (Aeronautical Information Manual): A publication that explains procedures, regulations, and safe operating practices for pilots and air traffic personnel.
AIP (Aeronautical Information Publication): A country's official manual containing essential aeronautical information, procedures, and charts required for flight planning.
Aircraft: Any machine capable of sustained flight through the atmosphere, including airplanes, helicopters, gliders, balloons, and airships.
Airfield: A general term for a landing area for aircraft, often smaller or less developed than a full commercial airport.
Airframe: The structural components of an aircraft, including the fuselage, wings, and empennage, excluding the engines and onboard systems.
Airplane: A powered, fixed-wing aircraft that generates lift from its wings as it moves forward through the air.
Airport: A facility with runways, terminals, and support infrastructure used for the takeoff, landing, and servicing of aircraft.
Airship: A powered, steerable lighter-than-air aircraft that uses buoyant gas, such as helium, to stay aloft.
Airspeed: An aircraft's speed relative to the surrounding air, commonly expressed as Indicated Airspeed (IAS), True Airspeed (TAS), or Ground Speed (GS).
Airspeed Indicator: A cockpit instrument that displays the aircraft's speed through the air, derived from pitot and static pressure readings.
Airway: A designated corridor of airspace, identified by a route number, used to structure and separate en-route air traffic.
Airworthiness: The condition of an aircraft meeting the safety and design standards required for it to be legally operated.
Airworthiness Directive: A legally enforceable order issued by an aviation authority requiring correction of an unsafe condition found in an aircraft type.
All Call: A cabin crew procedure in which each crew station reports in over the intercom to confirm readiness before departure.
Alternate Airport: A backup airport listed in a flight plan where a flight can divert if it cannot land at its intended destination.
Altimeter: An instrument that shows an aircraft's altitude based on atmospheric pressure readings.
Annex (ICAO Annex): One of the technical documents issued by ICAO establishing international standards and recommended practices for aviation.
Approach: The phase of flight in which an aircraft descends and aligns itself to land at an airport.
Approach Control: The air traffic control unit that manages aircraft as they descend and sequence toward final approach near an airport.
APU (Auxiliary Power Unit): A small onboard turbine engine that supplies electrical power and compressed air when the main engines are not running.
Area Control Center: An air traffic control facility responsible for managing aircraft in en-route airspace between departure and arrival areas.
Attitude Indicator: A cockpit instrument that shows the aircraft's orientation relative to the horizon, indicating pitch and bank.
Autopilot: A system that automatically controls an aircraft's flight path, reducing the manual workload on pilots.
AWB (Air Waybill): A shipping document that accompanies air cargo, serving as a contract of carriage and receipt for the shipment.

B 14 terms

Basic Economy: The cheapest economy fare class, usually with restrictions like no seat selection, limited changes, and boarding last.
Boarding Group: The assigned order in which passengers board the aircraft, often tied to fare class, loyalty status, or seat location.
B Check: A maintenance inspection more extensive than an A Check, performed less frequently to examine additional aircraft systems.
Baggage Claim: The airport area where arriving passengers collect their checked luggage after a flight.
Balloon: A lighter-than-air aircraft with no engine that rises using heated air or a lifting gas and drifts with the wind.
Base Maintenance: Extensive aircraft maintenance performed in a hangar over an extended period, covering deeper checks than routine line maintenance.
Beacon: A flashing light at an airport, typically green and white, that identifies the airport's location at night or in poor visibility.
Bearing: The horizontal compass direction from one point to another, measured in degrees from 0 to 360.
Best Glide Speed: The airspeed that allows an aircraft to travel the greatest distance for a given loss of altitude with no engine power.
Black Box: The common name for the Flight Data Recorder (FDR) and Cockpit Voice Recorder (CVR), which capture flight data and cockpit audio.
Boarding: The process of passengers entering the aircraft and taking their seats prior to departure.
Brace Position: A protective posture passengers are instructed to adopt before an emergency landing to reduce the risk of injury.
Briefing: A pre-flight session where pilots or crew review weather, route, and airport conditions before departure.
Bulkhead: An interior partition wall inside an aircraft cabin, often separating cabin classes or sections.

C 30 terms

Cabin Pressure: The regulated air pressure maintained inside an aircraft cabin at altitude, kept higher than the outside air to allow passengers to breathe comfortably without supplemental oxygen.
Codeshare: An arrangement where a flight is marketed and sold by multiple airlines under their own flight numbers, even though only one airline actually operates it.
C Check: A major maintenance check performed at longer intervals, involving detailed inspection of many aircraft systems and structures.
Cabin: The interior compartment of an aircraft where passengers and crew are seated during flight.
Cabin Crew: Flight attendants responsible for passenger safety, service, and emergency procedures during a flight.
Cabin Secure: A status report confirming that the cabin is prepared and safe for takeoff or landing.
CDL (Configuration Deviation List): A list specifying which external aircraft parts may be missing for a flight to still be dispatched safely, with limitations.
CDU (Control Display Unit): The cockpit interface pilots use to enter data into and interact with the Flight Management System.
Ceiling: The height of the lowest cloud layer covering more than half the sky, reported as broken or overcast.
Certificate of Airworthiness: An official document confirming that an aircraft complies with its type design and is fit to fly.
Check-in: The process of confirming a passenger's flight, issuing a boarding pass, and checking baggage before departure.
Clear Air Turbulence: Turbulence occurring in cloudless air, often near jet streams, that is difficult to detect visually or by radar.
Clearance: Official authorization from ATC for an aircraft to proceed with a specific route, altitude, takeoff, or landing.
Clearance Delivery: The ATC position that issues a departing aircraft's route and altitude clearance before it begins taxiing.
Cleared: Radio phraseology confirming that ATC has authorized a specific action, such as takeoff or an approach.
Cleared for Takeoff: An ATC instruction authorizing an aircraft to begin its takeoff roll on the runway.
Cleared to Land: An ATC instruction authorizing an aircraft to complete its approach and land on the runway.
Clearway: A defined area beyond the end of a runway that an aircraft may use during initial climb after takeoff.
Climb: The phase of flight in which an aircraft increases altitude after takeoff.
Cockpit: The forward compartment of an aircraft where the pilots sit and operate the flight controls.
Compass: An instrument that indicates direction relative to magnetic north, used as a basic navigation reference.
Contact Tower: An instruction directing a pilot to switch radio frequency and communicate with the airport control tower.
Container: A standardized unit used to hold and transport cargo or baggage in an aircraft's hold.
Controlled Airspace: Airspace in which air traffic control provides separation services to aircraft operating under specific flight rules.
CPDLC: Controller–Pilot Data Link Communications — a system allowing text-based instructions and requests between ATC and pilots instead of voice radio.
Crew Scheduling: The airline department responsible for assigning pilots and cabin crew to flights in compliance with duty-time rules.
Cross Check: A cabin crew procedure where each crew member verifies another's safety-related setup, such as door arming, before flight.
Crosswind: Wind blowing across, rather than along, the direction of a runway or an aircraft's flight path.
Cruise: The phase of flight where an aircraft maintains a relatively constant altitude and speed between climb and descent.
CTAF: Common Traffic Advisory Frequency — a designated radio frequency pilots use to self-announce position at airports without a control tower.

D 18 terms

D Check: The most extensive scheduled maintenance check, often involving near-complete disassembly and inspection of the aircraft.
Dangerous Goods: Cargo items that pose a risk to health, safety, or property during air transport and require special handling.
Datum: A reference point used to measure an aircraft's weight and balance and locate positions within it.
Dead Reckoning: A navigation method that estimates current position using known speed, heading, and elapsed time from a last known point.
Deadhead Crew: Airline crew members traveling as passengers to reposition for duty, rather than working the flight.
Decision Height (DH): The altitude during a precision approach at which a pilot must decide to either continue landing or execute a go-around.
Deferred Defect: A known minor aircraft fault that is permitted to remain unrepaired for a limited time under maintenance regulations.
Departure: The phase of flight covering an aircraft's takeoff and initial climb from an airport.
Departure Control: The ATC unit that manages aircraft immediately after takeoff until they are handed off to en-route control.
Descent: The phase of flight in which an aircraft reduces altitude on its way toward landing.
Dew Point: The temperature at which air becomes saturated with moisture, relevant to fog and icing forecasts.
DGCA: Directorate General of Civil Aviation — the national civil aviation regulatory authority in various countries, including Indonesia.
Dispatch: The airline function responsible for planning and authorizing a flight, including fuel, route, and weight calculations.
Displaced Threshold: A runway threshold moved inland from the physical start of the pavement, usually due to an obstacle in the approach path.
Ditching: An emergency landing of an aircraft on water.
Diversion: A flight's unplanned landing at an airport other than its original destination.
DME (Distance Measuring Equipment): A ground-based navigation aid that provides pilots with a continuous readout of slant-range distance to a station.
Drone: An unmanned aircraft, also called a UAV, flown remotely or autonomously without an onboard pilot.

E 17 terms

ETOPS: Extended-range Twin-engine Operational Performance Standards — certification allowing twin-engine aircraft to fly routes far from diversion airports, such as over oceans.
Error Fare: An unintentionally mispriced airfare, usually caused by a technical or human error, that can offer significant savings if booked before it's corrected.
EASA: European Union Aviation Safety Agency — the regulatory body responsible for civil aviation safety across the European Union.
ECAM: Electronic Centralised Aircraft Monitor — an Airbus cockpit display system that presents engine and aircraft system status and warnings.
Economy Cruise: A cruise speed setting optimized for fuel efficiency rather than maximum speed.
EFIS: Electronic Flight Instrument System — a display system that replaces traditional mechanical flight instruments with digital screens.
EICAS: Engine Indicating and Crew Alerting System — a Boeing cockpit display showing engine data and system alerts.
Elevation: The height of a location, such as an airport, measured from mean sea level.
Elevator: The hinged control surface on the horizontal stabilizer that controls an aircraft's pitch, or nose-up/nose-down movement.
ELT (Emergency Locator Transmitter): A device that automatically activates on impact to transmit a distress signal, helping search-and-rescue teams locate an aircraft.
Emergency: A situation involving a serious threat to the safety of an aircraft, its occupants, or others, requiring urgent action.
Empennage: The tail assembly of an aircraft, including the horizontal and vertical stabilizers and their control surfaces.
Endurance: The maximum length of time an aircraft can remain airborne with a given fuel load.
Engine: The power plant that generates thrust or lift to propel an aircraft through the air.
ETA (Estimated Time of Arrival): The predicted time at which a flight is expected to arrive at its destination.
ETD (Estimated Time of Departure): The predicted time at which a flight is expected to depart from its origin.
Evacuation: The rapid exit of passengers and crew from an aircraft, typically in response to an emergency on the ground.

F 22 terms

Fare Class: A booking code (such as Y, W, or Q) that determines the price, flexibility, and mileage earning of a ticket, separate from the physical cabin (economy, business, first).
FAA: Federal Aviation Administration — the U.S. federal body regulating civil aviation, widely referenced as a global standard-setter.
FAF (Final Approach Fix): The point on an instrument approach where an aircraft begins its final descent toward the runway.
Fairing: A structural cover fitted to an aircraft to smooth airflow and reduce drag over a joint or gap.
Fire Bottle: A pressurized fire extinguishing canister installed in aircraft engines or cargo holds for emergency use.
FIS (Flight Information Service): A service providing pilots with advisory information such as weather and traffic in a given area.
Fix: A defined geographic point used in navigation, often marking a position along a route or an approach.
Flap: A movable panel on the trailing edge of a wing that increases lift and drag, typically used during takeoff and landing.
Flare: The final maneuver before touchdown in which a pilot raises the aircraft's nose to slow the descent rate for a smooth landing.
Flight Attendant: A cabin crew member responsible for passenger safety, service, and emergency procedures during flight.
Flight Deck: Another term for the cockpit, especially common on larger commercial aircraft.
Flight Director: A cockpit display that shows pilots the pitch and roll commands needed to follow a selected flight path.
Flight Following: An ATC advisory service that tracks an aircraft's position and alerts pilots to nearby traffic, without full separation control.
Flight Level: A standardized pressure altitude expressed in hundreds of feet, such as FL350 for 35,000 feet, used above a set transition altitude.
Flight Plan: A document filed before a flight detailing the route, altitude, fuel, and other operational information.
FMC (Flight Management Computer): The computer component of the Flight Management System that calculates navigation, performance, and fuel data.
FMS (Flight Management System): An integrated onboard system that automates navigation, performance calculations, and flight planning tasks.
FOD (Foreign Object Debris): Loose material, such as metal fragments or debris, on airport surfaces that can damage aircraft engines or tires.
Freight: Cargo transported by air rather than passengers.
Freight Forwarder: A company that arranges the shipment of air cargo on behalf of shippers.
Fuel Burn: The rate or total amount of fuel consumed by an aircraft during a flight.
Fuselage: The main body of an aircraft that houses the cabin, cockpit, and cargo compartments.

G 10 terms

Galley: The compact kitchen area aboard an aircraft used for preparing and storing food and beverages.
Gate: The designated area at a terminal where passengers board and disembark an aircraft.
Glide Slope: The vertical guidance component of the Instrument Landing System that provides pilots with the correct descent angle for landing.
Glider: An unpowered, fixed-wing aircraft that sustains flight using rising air currents rather than an engine.
GNSS: Global Navigation Satellite System — the general term for satellite-based positioning systems, of which GPS is one example.
Go-Around: A pilot's decision to abandon a landing attempt and climb away to try again, usually for safety reasons.
GPS (Global Positioning System): A U.S. satellite navigation system used to determine an aircraft's precise position, widely used in aviation navigation.
GPWS: Ground Proximity Warning System — a system that alerts pilots when the aircraft is dangerously close to terrain.
Ground Control: The ATC position that directs aircraft movement on taxiways, aprons, and other non-runway areas of an airport.
Ground Speed: An aircraft's actual speed relative to the ground, affected by wind speed and direction.

H 13 terms

Hidden City Ticketing: Booking a flight with a connection where the connecting city is the traveler's real destination, skipping the final leg — a practice most airlines prohibit in their terms of service.
Hangar: A large structure used to store, maintain, or repair aircraft, shielded from weather.
Heading: The direction in which an aircraft's nose is pointed, which may differ from its actual ground track in crosswinds.
Heading Indicator: A cockpit instrument that displays the aircraft's current heading, typically synchronized with the compass.
Headwind: Wind blowing directly against an aircraft's direction of travel, which reduces ground speed.
Helicopter: A rotorcraft that achieves lift and thrust from one or more powered horizontal rotors, enabling vertical takeoff and landing.
Helipad: A designated landing area specifically designed for helicopters.
Holding Fix: A specific navigational point around which an aircraft flies a holding pattern while awaiting further clearance.
Holding Pattern: A predefined racetrack-shaped flight path used to keep an aircraft in a safe area while awaiting clearance to proceed.
Holding Point: A marked location on a taxiway where an aircraft must stop and wait for ATC clearance before entering a runway.
Horizontal Stabilizer: The fixed horizontal tail surface that provides pitch stability, usually paired with the elevator.
Hub Airport: A central airport an airline uses to connect passengers between multiple spoke destinations.
Hub-and-Spoke: An airline network model that routes traffic through central hub airports rather than flying only direct point-to-point routes.

I 10 terms

IATA: International Air Transport Association — a trade association that sets commercial standards, such as airline and airport codes, for the industry.
ICAO: International Civil Aviation Organization — a United Nations agency that establishes global standards for aviation safety and operations.
Icing: The accumulation of ice on an aircraft's surfaces, which can degrade lift and control if not managed.
Ident: A pilot action that highlights the aircraft's return on an ATC radar screen when requested by a controller.
IFR (Instrument Flight Rules): A set of rules under which a flight is conducted using cockpit instruments for navigation and control, typically in poor visibility.
ILS (Instrument Landing System): A precision ground-based system that guides an aircraft's approach and landing using lateral and vertical radio signals.
IMC (Instrument Meteorological Conditions): Weather conditions poor enough that flight must be conducted by reference to instruments rather than visually.
INS (Inertial Navigation System): A self-contained navigation system that calculates position using motion sensors, without needing external signals.
IRS (Inertial Reference System): A modern, more precise successor to the INS, providing attitude and navigation data to an aircraft's systems.
ISA (International Standard Atmosphere): A model atmosphere used as a reference baseline for aircraft performance calculations and instrument calibration.

J 2 terms

Jet Bridge: An enclosed, movable walkway connecting an airport terminal gate directly to an aircraft's door.
Jumpseat: A folding seat used by cabin or cockpit crew, sometimes also offered to authorized off-duty crew or officials.

K 1 term

Knots (kts): A unit of speed equal to one nautical mile per hour, the international standard for measuring aviation speed.

L 15 terms

Layover: A stop between connecting flights at an intermediate airport, typically lasting a few hours, as opposed to a longer stopover.
Lounge Access: Entry to airline or airport lounges, typically granted through premium tickets, elite status, lounge memberships, or certain credit cards.
Landing: The phase of flight in which an aircraft descends to and touches down on a runway.
Landing Gear: The wheeled or floating structure that supports an aircraft on the ground and absorbs landing impact.
Life Vest: An inflatable personal flotation device stowed under passenger seats for use in a water emergency.
Liftoff: The moment an aircraft's wheels leave the ground during takeoff.
Line Maintenance: Routine, minor maintenance and inspections performed on an aircraft between flights, typically at the gate.
Line Up and Wait: An ATC instruction directing a pilot to taxi onto the runway and wait there before takeoff clearance is given.
Live Animals: A cargo category covering the transport of live animals, subject to specific handling and documentation rules.
LNAV (Lateral Navigation): A navigation mode that guides an aircraft horizontally along a programmed flight path.
Load Sheet: A document detailing an aircraft's weight, balance, and passenger and cargo distribution before departure.
Loadmaster: A crew member responsible for planning and supervising the loading and weight balance of cargo aircraft.
Localizer: The horizontal guidance component of the Instrument Landing System that aligns an aircraft with the runway centerline.
Logbook: An official record documenting an aircraft's flight hours, maintenance history, and defects.
LPV (Localizer Performance with Vertical Guidance): A satellite-based approach procedure that provides precision-like lateral and vertical guidance similar to an ILS.

M 16 terms

Magnetic Heading: An aircraft's heading measured relative to magnetic north rather than true north.
Manifest: A document listing all passengers, crew, and cargo carried on a flight.
Marshalling: Hand or light signals used by ground personnel to guide an aircraft's movement on the ramp.
Maximum Cruise: The highest cruise power setting an aircraft can sustain, prioritizing speed over fuel efficiency.
Mayday: The internationally recognized radio distress call, repeated three times, indicating a life-threatening emergency.
MDA (Minimum Descent Altitude): The lowest altitude a pilot may descend to during a non-precision approach without visual contact with the runway.
MEL (Minimum Equipment List): A list specifying which aircraft equipment may be inoperative while still permitting safe, legal dispatch of a flight.
METAR: A standardized routine report of current weather conditions at an airport, used for flight planning.
MFD (Multi-Function Display): A cockpit screen that can present various types of flight, navigation, or system information selected by the pilot.
Minimum Safe Altitude: The lowest altitude that provides safe clearance above terrain and obstacles in a given area.
Missed Approach: The published procedure a pilot follows after a go-around, guiding the aircraft safely away for another attempt or diversion.
MLW (Maximum Landing Weight): The highest total weight at which an aircraft is certified to safely land.
Monitor: An ATC instruction directing a pilot to listen to a specified frequency without necessarily making radio contact yet.
MSL (Mean Sea Level): The average level of the ocean's surface, used as the standard reference point for measuring altitude.
MTOW (Maximum Takeoff Weight): The highest total weight at which an aircraft is certified to safely attempt takeoff.
MZFW (Maximum Zero Fuel Weight): The maximum weight of an aircraft and its payload permitted before fuel weight is added.

N 5 terms

Nacelle: The external housing that encloses an aircraft engine, separate from the main fuselage.
NDB (Non-Directional Beacon): A ground-based radio transmitter used with an ADF receiver to help pilots determine bearing to the station.
Negative: Radio phraseology meaning "no," used to avoid confusion over a plain "no" on radio transmissions.
Nose: The forward-most section of an aircraft's fuselage.
NOTAM (Notice to Air Missions): An official bulletin alerting pilots to short-term hazards, closures, or changes to facilities or procedures.

O 5 terms

Open Jaw: A round-trip itinerary where you fly into one city and depart from a different one, without booking a separate one-way ticket.
OAT (Outside Air Temperature): The actual air temperature outside the aircraft, uncorrected for the effects of airspeed.
Overhaul: A thorough inspection and rebuild of an aircraft component, often an engine, to restore it to a serviceable condition.
Oversized Cargo: Freight that exceeds standard dimensions and requires special handling or aircraft configuration.
Oxygen Mask: An emergency device that supplies supplemental oxygen to passengers or crew if cabin pressure is lost.

P 15 terms

Pallet: A flat platform used to consolidate and load cargo as a single unit into an aircraft's hold.
Pan-Pan: An internationally recognized radio urgency call, less severe than Mayday, indicating a situation that requires assistance but is not immediately life-threatening.
PAPI (Precision Approach Path Indicator): A row of lights beside a runway that shows pilots, through a red-and-white color pattern, whether they are on the correct glide path.
Part 121: A section of U.S. federal aviation regulations governing scheduled commercial airline operations.
Part 91: A section of U.S. federal aviation regulations governing general operating and flight rules for most aircraft.
Payload: The total weight of passengers, baggage, and cargo an aircraft carries, excluding fuel and operating weight.
PBN (Performance-Based Navigation): A navigation framework that relies on aircraft system performance requirements rather than specific ground-based aids.
Perishable Cargo: Freight, such as fresh food or flowers, that requires time-sensitive or temperature-controlled handling.
PFD (Primary Flight Display): The main cockpit screen showing critical flight data such as airspeed, altitude, and attitude.
Piston Engine: A reciprocating engine that generates power through the movement of pistons, commonly used in smaller aircraft.
Pitch: The rotational movement of an aircraft's nose up or down around its lateral axis.
Pressure: Atmospheric pressure, a key input for altimeter readings and weather forecasting in aviation.
Propeller: A rotating set of blades that converts engine power into thrust to move an aircraft forward.
Purser: The senior cabin crew member responsible for overseeing the flight attendant team and cabin service.
Pushback: The process of towing an aircraft backward away from the gate using a tow vehicle before it taxis under its own power.

Q 2 terms

QFE: An altimeter setting referenced to airfield elevation, showing height above the airport rather than above sea level.
QNH: An altimeter setting referenced to sea level pressure, allowing altitude to be read as height above mean sea level.

R 19 terms

Radar: A system that uses radio waves to detect the position, speed, and distance of aircraft for air traffic control.
Radome: A protective, weatherproof cover housing an aircraft's radar antenna, usually located in the nose.
Raft: An inflatable life raft carried on aircraft that may fly over water, used in a ditching emergency.
Ramp: The paved area of an airport used for aircraft parking, loading, and servicing, also called the apron.
Range: The maximum distance an aircraft can fly on a given fuel load under specified conditions.
Readback: A pilot's repetition of an ATC instruction back to the controller to confirm it was correctly understood.
Rib: A structural component inside a wing that gives it shape and supports the outer skin.
RNAV (Area Navigation): A navigation method allowing aircraft to fly on any desired flight path within the coverage of navigation aids, rather than direct to/from stations.
RNP (Required Navigation Performance): An RNAV standard that requires an aircraft to monitor and alert if its navigation accuracy falls outside a defined tolerance.
Roger: Radio phraseology confirming that a message has been received and understood.
Roll: The rotational movement of an aircraft around its longitudinal axis, controlled primarily by the ailerons.
Rotation: The point during takeoff when the pilot raises the aircraft's nose to lift off the runway.
Rotation Speed (Vr): The airspeed at which a pilot begins to rotate the aircraft's nose upward during takeoff.
Rotorcraft: An aircraft that generates lift using one or more rotating rotor blades, such as a helicopter.
Rudder: The hinged control surface on the vertical stabilizer that controls an aircraft's yaw.
Runway: The paved strip at an airport dedicated to aircraft takeoffs and landings.
Runway Threshold: The beginning of the portion of a runway designated as usable for landing.
RVR (Runway Visual Range): A measurement of the horizontal distance a pilot can see down a runway, used in low-visibility operations.
RVSM (Reduced Vertical Separation Minimum): A standard allowing reduced vertical spacing between aircraft at high altitudes, increasing airspace capacity.

S 25 terms

Safety Demo: The pre-flight briefing, given live or by video, explaining emergency procedures and equipment to passengers.
Sailplane: A glider specifically designed for soaring, capable of sustained unpowered flight using rising air currents.
SAT (Static Air Temperature): The actual outside air temperature unaffected by the aircraft's speed, also called Outside Air Temperature.
Say Again: Radio phraseology used to request that a transmission be repeated.
Separation: The minimum required distance, vertically or horizontally, that ATC maintains between aircraft to ensure safety.
Service Bulletin: A manufacturer's recommendation for inspecting, modifying, or repairing an aircraft, which may or may not be mandatory.
SID (Standard Instrument Departure): A published, standardized route an aircraft follows after takeoff to transition safely into en-route airspace.
SIGMET: A weather advisory warning of hazardous conditions, such as severe turbulence or icing, significant to aircraft safety.
Silent Review: A cabin crew practice of mentally reviewing emergency procedures before each flight.
Slat: A movable panel on the leading edge of a wing that extends to increase lift at low speeds.
Slot Time: An allocated time window during which an aircraft is authorized to take off or land at a congested airport.
Smoke Hood: A protective device worn over the head to filter smoke and toxic fumes during an in-flight emergency.
Snag: An informal term for a minor mechanical fault or defect reported on an aircraft.
Spar: The main structural beam running through a wing that bears most of its load.
Speed Brake: A movable surface that increases drag to slow an aircraft or increase its rate of descent.
Spoiler: A panel on the upper wing surface that disrupts airflow to reduce lift, used to aid descent or slow the aircraft after landing.
Squawk: A four-digit transponder code entered by a pilot to identify the aircraft on ATC radar, such as 7700 for a general emergency.
Squawk Ident: An ATC instruction directing a pilot to activate the transponder's Ident function to highlight the aircraft on radar.
Stabilizer: A fixed aircraft surface, horizontal or vertical, that provides stability in pitch or yaw.
Stall: A dangerous condition in which the angle of attack becomes too high, disrupting airflow over the wing and causing a loss of lift.
Stall Speed: The minimum airspeed below which an aircraft's wing can no longer generate enough lift to sustain flight.
Standby: Radio phraseology asking the other party to wait, indicating the speaker will respond shortly.
STAR (Standard Terminal Arrival Route): A published, standardized route an aircraft follows when arriving into terminal airspace before approach.
Stopway: An area beyond the runway end designated for use in stopping an aircraft during an aborted takeoff.
SVFR (Special VFR): A clearance allowing flight under visual rules within controlled airspace despite weather conditions below normal VFR minimums.

T 27 terms

TAF: Terminal Aerodrome Forecast — a standardized forecast of expected weather conditions at an airport over a set period.
Tail: The rear section of an aircraft, typically encompassing the empennage and its control surfaces.
Tailwind: Wind blowing in the same direction as an aircraft's travel, which increases ground speed.
Takeoff: The phase of flight in which an aircraft accelerates on the runway and becomes airborne.
TAT (Total Air Temperature): The air temperature measured including the heating effect caused by the aircraft's speed through the air.
TAWS (Terrain Awareness and Warning System): A system that alerts pilots to potential collisions with terrain using onboard databases and positioning data.
Taxi: The movement of an aircraft on the ground under its own power, between the gate, runway, and other airport areas.
Taxiway: A paved path connecting an airport's apron to its runways, used for aircraft ground movement.
TCAS (Traffic Collision Avoidance System): An onboard system that detects nearby aircraft and issues alerts or maneuvers to avoid mid-air collisions.
Terminal: The airport building where passengers check in, pass security, and board or disembark flights.
Threshold: The starting line of the portion of a runway usable for landing.
Thunderstorm: A weather system producing lightning, heavy rain, and often turbulence, posing a significant hazard to aircraft.
Touchdown: The moment an aircraft's wheels make contact with the runway during landing.
Touchdown Zone: The first section of a runway, typically the initial 3,000 feet, where landing aircraft are expected to touch down.
Tower: The ATC facility, and controllers within it, responsible for aircraft on the runway and in the immediate airport vicinity.
Track: The actual path an aircraft follows over the ground, which may differ from its heading due to wind.
Transition Altitude: The altitude at which pilots switch from local altimeter settings to a standard pressure setting while climbing.
Transition Level: The lowest usable flight level, at or above the transition altitude, when descending to local altimeter settings.
Transponder: An onboard device that responds to radar signals by transmitting the aircraft's identity, altitude, and position to ATC.
Trim Tab: A small adjustable surface on a control surface that helps reduce the pilot's manual control pressure.
True Heading: An aircraft's heading measured relative to true (geographic) north rather than magnetic north.
Turbofan: A jet engine design that uses a large front fan to bypass air around the engine core, improving efficiency.
Turbojet: An early jet engine design that produces thrust entirely by expelling exhaust gases through the engine core.
Turboprop: An engine that uses a gas turbine to drive an external propeller, combining jet and propeller technology.
Turbulence: Irregular air movement that causes an aircraft to experience sudden, unpredictable changes in altitude or attitude.
Turn Coordinator: A cockpit instrument showing the rate and direction of an aircraft's turn.
Turnaround: The full process of preparing an aircraft for its next flight after landing, including unloading, cleaning, and boarding.

U 5 terms

UAS (Unmanned Aircraft System): The complete system comprising a drone, its control station, and the communication link between them.
UAV (Unmanned Aerial Vehicle): An aircraft that operates without a pilot on board, commonly known as a drone.
ULD (Unit Load Device): A standardized container or pallet used to consolidate cargo and baggage for loading into an aircraft's hold.
Uncontrolled Airspace: Airspace in which air traffic control does not provide separation services, requiring pilots to self-manage traffic avoidance.
UNICOM: A non-towered airport radio frequency used for pilots to communicate airport advisories and coordinate traffic.

V 12 terms

V-Speeds: A standard set of reference speeds, such as V1, VR, and V2, that define key performance points during takeoff and landing.
V1: The takeoff decision speed, beyond which a pilot must continue the takeoff rather than attempt to stop.
V2: The minimum safe takeoff climb speed an aircraft must maintain after an engine failure during takeoff.
Vector: A specific heading assigned by ATC to guide an aircraft's course for traffic separation or approach sequencing.
Vertical Speed Indicator: A cockpit instrument showing the rate at which an aircraft is climbing or descending.
Vertical Stabilizer: The fixed vertical tail surface that provides directional stability, paired with the rudder.
VFR (Visual Flight Rules): Flight rules under which a pilot navigates and maintains separation primarily by visual reference outside the aircraft.
Visibility: The greatest horizontal distance at which objects can be clearly seen, a key factor in flight planning.
VMC (Visual Meteorological Conditions): Weather conditions clear enough to permit flight under Visual Flight Rules.
VNAV (Vertical Navigation): A navigation mode that manages an aircraft's climb, cruise, and descent profile automatically.
VOR (VHF Omnidirectional Range): A ground-based navigation aid that transmits signals allowing aircraft to determine their bearing from the station.
VREF: The reference approach speed used by pilots as a target airspeed during landing.

W 7 terms

Wake Turbulence: Turbulent air left behind an aircraft's wings as it flies, which following aircraft must avoid by maintaining safe separation distances.
Waypoint: A defined geographic coordinate used to mark a point along a flight route.
Wilco: Radio phraseology meaning "will comply," confirming that an instruction was received and will be followed.
Wind Shear: A sudden change in wind speed or direction over a short distance, which can be hazardous during takeoff or landing.
Windsock: A fabric cone mounted at an airport that indicates wind direction and approximate speed.
Wing: The airfoil-shaped structure extending from an aircraft's fuselage that generates the lift needed for flight.
Winglet: An upward-angled extension at a wingtip that reduces drag caused by wingtip vortices, improving fuel efficiency.