Aviation Codes Library

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Metar & Taf


1. General Report Type Codes

  • METAR
    Meteorological Aerodrome Report.
    A routine weather observation issued (usually hourly) to provide current conditions at an airport.

  • SPECI
    Special Weather Report.
    Issued when significant or rapid changes in weather occur between routine METAR reports.

  • AUTO
    Indicates that the report was generated automatically by weather sensors rather than by a human observer.

  • COR
    Corrected Report.
    Denotes that the current report is a correction to a previously issued report.

  • NIL
    Used when there is nothing noteworthy to report beyond standard conditions.


2. Time and Date Codes

  • DDHHMMZ
    The date-time group format where:

    • DD: Day of the month
    • HHMM: Time in hours and minutes
    • Z: Zulu time (UTC)
      Example: 151230Z = 15th day of the month at 12:30 UTC.
  • Z
    Short for Zulu time, which is equivalent to Coordinated Universal Time (UTC).


3. Wind Codes

  • dddffKT
    The wind group in METAR reports:

    • ddd: Wind direction in degrees true (e.g., 180 means wind from the south)
    • ff: Wind speed in knots
    • KT: Knots
      Example: 18012KT = Wind from 180° at 12 knots.
  • VRB
    Variable.
    Used when the wind direction is not steady (typically when speeds are very low, below 3 knots).

  • G
    Gust.
    Indicates short bursts of higher wind speed. For instance, “G25” means gusts up to 25 knots.


4. Visibility Codes

  • SM
    Statute Miles.
    Used mainly in U.S. reports to indicate visibility in miles.

  • Meters (e.g., 9999)
    In many parts of the world, visibility is reported in meters. A value like “9999” typically means visibility is 10 km or more.

  • CAVOK
    Ceiling And Visibility OK.
    Indicates that:

    • Visibility is at least 10 km,
    • There are no significant clouds below 5,000 feet (or the highest minimum sector altitude), and
    • No significant weather phenomena (such as rain, snow, or thunderstorms) are present.

5. Weather Phenomena and Precipitation Codes

Intensity and Proximity Modifiers

  • - (Minus)
    Denotes light intensity of a phenomenon.

  • + (Plus)
    Denotes heavy intensity.

  • VC
    In the vicinity.
    Indicates that the weather phenomenon is occurring near (but not at) the reporting station.

Precipitation

  • DZ
    Drizzle.
    Light liquid precipitation consisting of very small droplets.

  • RA
    Rain.
    Precipitation in the form of water droplets.

  • SN
    Snow.
    Frozen precipitation in the form of snowflakes.

  • SG
    Snow Grains.
    Very small, opaque ice crystals—usually occurring in light precipitation.

  • IC
    Ice Crystals.
    Tiny ice particles falling from the sky.

  • PL
    Ice Pellets (Sleet).
    Formed when rain partially freezes before reaching the ground.

  • GR
    Hail.
    Spherical ice pellets that form in strong convective storms.

  • GS
    Small Hail or Snow Pellets.
    Generally smaller than typical hail.

  • UP
    Unknown Precipitation.
    Used when the type of precipitation cannot be determined.

Obscurations and Other Phenomena

  • BR
    Mist.
    Fine droplets suspended in the air that reduce visibility, but typically not as severely as fog.

  • FG
    Fog.
    A thick cloud of water droplets at ground level causing significantly reduced visibility.

  • FU
    Smoke.
    Usually from fires or industrial activity; can reduce visibility.

  • VA
    Volcanic Ash.
    Fine volcanic particles suspended in the atmosphere, dangerous for aircraft.

  • DU
    Dust.
    Fine particles that can lower visibility, especially in arid regions.

  • SA
    Sand.
    Loose sand being blown by the wind, reducing visibility.

  • HZ
    Haze.
    A slight obscuration of the sky caused by dust, smoke, or pollution.

  • PO
    Dust/Sand Whirls.
    Small swirling eddies of dust or sand often seen in windy conditions.

  • SQ
    Squalls.
    Brief, sudden increases in wind speed often associated with rain or storms.

  • SS
    Sandstorm.
    Intense winds carrying large amounts of sand, reducing visibility dramatically.

  • DS
    Duststorm.
    Similar to a sandstorm, but primarily involving dust.

  • FC
    Funnel Cloud.
    A rotating column of air that has not reached the ground, sometimes a precursor to a tornado.


6. Cloud Cover Codes

  • SKC
    Sky Clear.
    Indicates that no clouds are observed.

  • CLR
    Clear.
    Similar to SKC, used especially in U.S. reports to denote no clouds below a certain altitude.

  • FEW
    Few.
    1–2 oktas (eighths) of the sky covered by clouds.

  • SCT
    Scattered.
    3–4 oktas of cloud cover.

  • BKN
    Broken.
    5–7 oktas, meaning the sky is mostly covered by clouds but not completely overcast.

  • OVC
    Overcast.
    8 oktas, indicating full cloud cover.

  • VV
    Vertical Visibility.
    Used when the sky is obscured (e.g., by fog or heavy precipitation) and only vertical distance can be measured.

  • CB
    Cumulonimbus.
    Towering clouds associated with thunderstorms and convective activity.

  • TCU
    Towering Cumulus.
    Cumulus clouds with significant vertical development that may signal unstable atmospheric conditions.


7. Temperature and Dew Point Codes

  • T/D Format (e.g., 15/08)
    The first number represents the temperature in degrees Celsius, and the second number represents the dew point in degrees Celsius.

  • M Prefix
    When “M” precedes a number (e.g., M05), it indicates a negative value (below zero).


8. Altimeter/Pressure Codes

  • Q**
    Indicates the altimeter setting in hectopascals (hPa).
    Example: Q1013 means an altimeter setting of 1013 hPa.

  • A**
    Used mainly in U.S. reports, indicating the altimeter setting in inches of mercury (inHg).
    Example: A2992 translates to 29.92 inHg.


9. Remarks and Additional Information

  • RMK
    Remarks.
    A section at the end of the report where additional, non-standard information is provided.

  • NOSIG
    No Significant Change.
    Typically found in TAFs, meaning that no significant weather changes are expected during the forecast period.

  • BECMG
    Becoming.
    Indicates that weather conditions are expected to change gradually from one state to another.

  • TEMPO
    Temporary.
    Signals that there will be temporary fluctuations or brief periods of differing weather conditions.

  • PROB30 / PROB40
    Indicates a 30% or 40% probability that a certain weather phenomenon will occur during the forecast period.

  • AMD
    Amended.
    Shows that the forecast has been updated from a previous version.

  • COR
    As noted above, signifies that the forecast or report has been corrected.


10. TAF-Specific Codes

  • TAF
    Terminal Aerodrome Forecast.
    A detailed weather forecast for a specific airport, usually covering a 24- to 30-hour period (extended forecasts may cover up to 48 hours).

  • FM
    From.
    Marks the beginning of a period during which forecast conditions are expected to change.
    Example: FM1200 indicates that from 12:00 UTC onward, new conditions will prevail.

  • TL
    Until.
    Used to denote the end time for a particular forecast period or change in conditions.

  • AT
    Occasionally used in TAFs to specify a particular time within the forecast period.

  • NSW
    No Significant Weather.
    Indicates that no notable weather phenomena are expected during the period in question.


11. Additional Meteorological Abbreviations

  • NSC
    No Significant Cloud.
    Indicates there are no significant clouds below 5000 feet and no CB or TCU observed.
  • CBMAM
    Cumulonimbus Mammatus.
    A specific type of cumulonimbus cloud with a mammatus base, often indicating severe turbulence.
  • SH
    Showers.
    Used to denote convective precipitation. E.g., SHRA = rain showers.
  • TS
    Thunderstorm.
    Used when thunderstorm activity is present. E.g., TSRA = thunderstorm with rain.

12. Wind Direction Variability Code

  • dddVddd
    Indicates variable wind direction when it fluctuates more than 60° during the observation. Example: 180V240 means the wind is varying between 180° and 240°.

13. SPECI Trend Codes

  • TREND
    Indicates short-term forecast appended to a SPECI report.
  • TEMPO, PROB30/PROB40, and NOSIG
    May appear within the TREND section to describe expected short-term variations.

14. Composite METAR/TAF Examples

Example METAR: METAR LIRF 151230Z 18012KT 9999 FEW020 SCT030 18/08 Q1013 NOSIG
Translation: Routine report from Rome Fiumicino on the 15th at 12:30 UTC. Wind from 180° at 12 kt, visibility greater than 10 km, few clouds at 2000 ft, scattered clouds at 3000 ft, temperature 18°C, dew point 8°C, pressure 1013 hPa. No significant changes expected.

Example TAF: TAF LIRF 151100Z 1512/1612 18012KT CAVOK BECMG 1515/1517 22015KT
Translation: Forecast for Rome Fiumicino issued on the 15th at 11:00 UTC, valid from the 15th at 12:00 to the 16th at 12:00 UTC. Wind from 180° at 12 kt, ceiling and visibility OK. Becoming between 15:00 and 17:00 UTC: wind from 220° at 15 kt.


Reference: ICAO Annex 3, WMO No. 306 Manual on Codes (FM 15–X METAR, FM 51–X TAF)


General Codes


1. Regulatory & Organizational Bodies

  • ICAO – International Civil Aviation Organization
    Role: A UN agency that sets global standards for aviation safety, security, efficiency, and environmental protection.
    Context: Its standards govern flight procedures, airspace design, and aircraft certification worldwide.

  • IATA – International Air Transport Association
    Role: A global trade association representing airlines.
    Context: Develops standards for ticketing, baggage handling, and operational procedures, and influences airline policies.

  • FAA – Federal Aviation Administration
    Role: The U.S. authority overseeing civil aviation.
    Context: Manages air traffic control, pilot licensing, aircraft certification, and U.S. airspace safety.

  • EASA – European Union Aviation Safety Agency – The European counterpart to the FAA. It ensures aviation safety across EU member states by setting regulations, certifying aircraft and parts, and overseeing flight operations.
  • CAA – Civil Aviation Authority
    Role: National bodies (e.g., the UK CAA) responsible for regulating and ensuring aviation safety within a country.

  • NTSB – National Transportation Safety Board
    Role: An independent U.S. agency that investigates aviation and other transportation accidents.
    Context: Its findings lead to crucial safety improvements.

  • AOC – Air Operator’s Certificate
    Role: Certification permitting an airline or commercial operator to conduct air transport operations.
    Context: Requires strict evaluation of operational procedures, maintenance, and training.

  • AIP – Aeronautical Information Publication
    Role: A comprehensive manual with essential aeronautical data.
    Context: Contains charts, procedures, and regulatory details vital for flight planning.

  • SOP – Standard Operating Procedure
    Role: Detailed, written instructions for routine operations.
    Context: Helps standardize processes (e.g., pre-flight checks, emergency procedures) to minimize error.

  • CRM – Crew Resource Management
    Role: Training that enhances cockpit communication, teamwork, and decision-making.
    Context: Reduces human error by promoting shared situational awareness.

  • FAR – Federal Aviation Regulations
    Role: The set of rules established by the FAA governing all U.S. civil aviation activities.

  • ATS – Air Traffic Services
    Role: A suite of services—including ATC, flight information, and alerting—to ensure safe and orderly aircraft movement.

  • EAFDM – European Authorities Coordination Group on Flight Data Monitoring – A working group that coordinates efforts among national authorities to enhance flight safety through flight data monitoring.
  • EAB – EASA Advisory Bodies – Expert panels that advise EASA on technical, operational, and regulatory matters.
  • EASA MB – EASA Management Board – Governing body responsible for strategic decisions and oversight of EASA's operations and priorities.
  • EASP – European Aviation Safety Programme – The overarching strategic framework aimed at improving aviation safety across Europe, developed under ICAO guidance.
  • EASp – European Aviation Safety Plan – The tactical component of the EASP. It identifies current safety issues and outlines targeted actions to mitigate risks within a defined time frame.
  • EBT – Evidence-Based Training
  • AOC – Air Operator Certificate
  • AMC – Acceptable Means of Compliance
  • AMOC – Alternative Method of Compliance
  • CAT – Commercial Air Transport
  • CSV – Certification Support for Validation
  • DLS – Data Link Services
  • ETSO – European Technical Standard Order
  • FSTD – Flight Simulation Training Device
  • MOC – Means of Compliance
  • PBN – Performance Based Navigation
  • TCO – Third Country Operator
  • UAS – Unmanned Aircraft Systems
  • AD – Airworthiness Directive
  • IS – Information Security
  • ADR – Aerodromes
  • SPO – Specialised Operations
  • ORO – Organisation Requirements for Air Operations
  • SP – Safety Publications
  • EWIS – Electrical Wiring Interconnection Systems

2. Navigation Systems & Equipment

  • VOR – VHF Omni-directional Range
    Role: A ground-based radio navigation aid that provides azimuth information.
    Example: Helps pilots maintain a course along established airways.

  • DME – Distance Measuring Equipment
    Role: Provides the slant range distance between an aircraft and a ground station.
    Context: Typically co-located with VORs.

  • NDB – Non-Directional Beacon
    Role: A radio transmitter emitting signals in all directions.
    Context: Used with an Automatic Direction Finder (ADF) for navigation, especially where VORs are sparse.

  • ILS – Instrument Landing System
    Role: Provides precision lateral (localizer) and vertical (glide slope) guidance during approaches.
    Context: Classified into CAT I, II, or III based on minimum decision height and runway visual range.

  • MLS – Microwave Landing System
    Role: An alternative precision approach system using microwave frequencies for guidance.

  • PAPI – Precision Approach Path Indicator
    Role: A set of lights that visually guides pilots to the proper glide path on landing.
    Example: The red/white light configuration indicates whether you’re high, low, or on target.

  • VASI – Visual Approach Slope Indicator
    Role: Similar to PAPI; uses calibrated light bars to help pilots maintain the correct approach angle.

  • RNAV – Area Navigation
    Role: Enables pilots to fly on any desired path within the range of navigation aids.
    Context: Increases routing flexibility and airspace efficiency.

  • RNP – Required Navigation Performance
    Role: Specifies navigation accuracy, integrity, and continuity requirements.
    Context: Essential for operations in complex or congested airspace.

  • GPS – Global Positioning System
    Role: A satellite-based system providing precise position and timing information.

  • GNSS – Global Navigation Satellite System
    Role: Encompasses all satellite navigation systems (e.g., GPS, GLONASS, Galileo, BeiDou).
    Context: Provides redundancy and global coverage.

  • TACAN – Tactical Air Navigation
    Role: A military system providing bearing and distance data.
    Context: Often combined with VOR to form VORTAC.

  • VORTAC – VOR/TACAN Combination
    Role: Offers both azimuth and distance information from a single facility.

  • PBN – Performance-Based Navigation
    Role: Establishes navigation requirements based on the performance of onboard systems rather than ground aids.

  • SBAS – Satellite-Based Augmentation System
    Role: Enhances satellite navigation accuracy by providing correction signals.
    Examples: WAAS in North America, EGNOS in Europe.

  • WAAS – Wide Area Augmentation System
    Role: A specific SBAS that improves GPS accuracy for precision approaches such as LPV.

  • LPV – Localizer Performance with Vertical Guidance
    Role: Provides precision approach capabilities using SBAS corrections, similar to ILS without ground-based localizers.


3. Flight Operations & Procedures

  • IFR – Instrument Flight Rules
    Role: Regulations that govern flight when pilots rely primarily on instruments.
    Context: Requires filing a flight plan and adhering to strict procedures during poor visibility.

  • VFR – Visual Flight Rules
    Role: Rules allowing flight when weather conditions permit pilots to navigate visually.
    Context: Depends on sufficient visibility and clear skies.

  • SID – Standard Instrument Departure
    Role: Predefined departure routes ensuring obstacle clearance and efficient traffic flow.
    Example: Used at airports with high traffic or challenging terrain.

  • STAR – Standard Terminal Arrival Route
    Role: Preplanned arrival paths to streamline descent and integration into terminal airspace.

  • FPL – Flight Plan
    Role: A document detailing the intended route, altitudes, speeds, and other operational parameters.

  • OFP – Operational Flight Plan
    Role: An enriched flight plan used by airlines containing additional performance data, fuel calculations, and alternate routing.

  • CTAF – Common Traffic Advisory Frequency
    Role: A frequency used at non-towered airports for pilots to communicate position and intentions.

  • TMA – Terminal Maneuvering Area
    Role: The controlled airspace surrounding an airport where arriving and departing traffic is sequenced.

  • CTR – Control Zone
    Role: An airspace zone around an airport where ATC services are provided.

  • RWY – Runway
    Role: The designated paved surface for takeoffs and landings.
    Example: Runways are numbered according to their magnetic alignment (e.g., RWY 09/27).

  • FL – Flight Level
    Role: Altitudes standardized by a fixed pressure setting (1013.25 hPa) used for high-altitude navigation.

  • QNH & QFE

    • QNH: Altimeter setting adjusted to mean sea level (MSL).
    • QFE: Altimeter setting reflecting the actual air pressure at the airfield (height above ground level).
  • RVSM – Reduced Vertical Separation Minimum
    Role: Allows aircraft to operate with reduced vertical spacing (typically 1,000 feet) between flight levels.

  • ODP – Obstacle Departure Procedure
    Role: Preplanned routes that ensure obstacle clearance during departure.

  • TODA, ASDA, & LDA

    • TODA (Takeoff Distance Available): Runway length plus clearway.
    • ASDA (Accelerate-Stop Distance Available): Runway length plus stopway for aborted takeoffs.
    • LDA (Landing Distance Available): The runway length available for landing.
  • MTOW & MLW

    • MTOW (Maximum Takeoff Weight): The highest weight at which an aircraft can safely take off.
    • MLW (Maximum Landing Weight): The highest weight at which an aircraft is allowed to land.
  • OEW & ZFW

    • OEW (Operating Empty Weight): The weight of the aircraft with all operational items but without payload or usable fuel.
    • ZFW (Zero Fuel Weight): The weight of the aircraft excluding usable fuel, critical for balance calculations.
  • ETOPS – Extended-range Twin-engine Operational Performance Standards
    Role: Guidelines allowing twin-engine aircraft to operate safely on long routes away from diversion airports.

  • FBO – Fixed Base Operator
    Role: A ground service provider at an airport offering fueling, hangaring, maintenance, and handling services.


4. Communication & Avionics Systems

  • ATC – Air Traffic Control
    Role: The service managing the safe and efficient movement of aircraft through clearances, instructions, and radar monitoring.

  • ATIS – Automatic Terminal Information Service
    Role: A continuously broadcast service that provides current weather, runway, and other essential information to pilots.

  • AWOS – Automated Weather Observing System
    Role: An automated system that collects and broadcasts weather data, particularly at smaller or remote airports.

  • ACARS – Aircraft Communications Addressing and Reporting System
    Role: A digital data link system for transmitting messages between aircraft and ground stations (e.g., flight plan updates, maintenance reports).

  • CPDLC – Controller–Pilot Data Link Communications
    Role: A text-based messaging system that supplements voice communications between pilots and controllers, reducing radio congestion.

  • ADS-B – Automatic Dependent Surveillance–Broadcast
    Role: A surveillance technology whereby aircraft automatically broadcast their position, speed, and other flight data.

  • HF, VHF, & UHF Radios

    • HF (High Frequency): For long-range communications over oceans or remote areas.
    • VHF (Very High Frequency): The primary band for civil aviation voice communications and some navigation signals.
    • UHF (Ultra High Frequency): Commonly used by military aviation and specific ground communications.
  • SATCOM – Satellite Communications
    Role: Provides voice and data links via satellites, crucial for remote and oceanic operations.

  • ATN – Aeronautical Telecommunication Network
    Role: A digital network interconnecting aircraft, ATC, and other stakeholders for efficient data exchange.

  • EFB – Electronic Flight Bag
    Role: A portable electronic device (tablet/laptop) that replaces paper-based manuals, charts, and documentation.

  • FMS/FMC – Flight Management System/Computer
    Role: An onboard system that automates flight planning, navigation, and performance management.

  • EFIS – Electronic Flight Instrument System
    Role: Digital cockpit displays that present essential flight data in a configurable format.

  • MFD & PFD – Multi-Function Display & Primary Flight Display

    • MFD: Combines navigation, weather, and traffic information on one screen.
    • PFD: Displays core flight data (attitude, airspeed, altitude, heading) as the primary reference.
  • EICAS/ECAM

    • EICAS (Engine Indication and Crew Alerting System): Used in Boeing aircraft to monitor engine/system performance and alert crews to anomalies.
    • ECAM (Electronic Centralized Aircraft Monitor): Airbus’s system that provides system status, checklists, and procedural guidance.
  • SART – Search and Rescue Transponder
    Role: A device that emits a distress signal when activated, aiding rescue operations.

  • TCAS – Traffic Collision Avoidance System
    Role: Provides collision avoidance advisories by detecting nearby transponder-equipped aircraft.

  • FANS – Future Air Navigation System
    Role: An evolving suite of technologies enhancing communication, navigation, and surveillance (especially over oceanic airspace).


5. Aircraft Systems & Components

  • APU – Auxiliary Power Unit
    Role: A small turbine engine that provides electrical and pneumatic power on the ground and assists with engine starts.

  • FDR – Flight Data Recorder
    Role: The “black box” that records flight parameters (altitude, speed, control inputs) for investigation purposes.

  • CVR – Cockpit Voice Recorder
    Role: Records cockpit audio, including pilot communications and ambient sounds, crucial for accident investigations.

  • ECS – Environmental Control System
    Role: Manages cabin pressurization, temperature, and ventilation to ensure passenger comfort and system reliability.

  • IRS – Inertial Reference System
    Role: Uses gyroscopes and accelerometers to determine the aircraft’s position, orientation, and velocity independently of external aids.

  • MCDU – Multipurpose Control and Display Unit
    Role: The pilot interface for the FMS, used to enter flight plans and adjust performance data.

  • HUD – Head-Up Display
    Role: A transparent display projecting flight data into the pilot’s forward view, enhancing situational awareness.

  • ELT – Emergency Locator Transmitter
    Role: Automatically transmits a distress signal in the event of a crash to facilitate search and rescue.

  • ADF – Automatic Direction Finder
    Role: Receives signals from NDBs to provide bearing information for navigation.

  • FMA – Flight Mode Annunciator
    Role: Displays the active autopilot modes and flight director commands to the pilot.


6. Safety, Emergency & Investigation Systems

  • GPWS – Ground Proximity Warning System
    Role: Alerts pilots when the aircraft is in dangerous proximity to terrain or obstacles, mitigating CFIT risks.

  • TAWS – Terrain Awareness and Warning System
    Role: An advanced version of GPWS that uses digital terrain databases for more precise alerts.

  • FOQA – Flight Operational Quality Assurance
    Role: Collects and analyzes flight data to identify trends, improve procedures, and prevent future incidents.

  • QRH – Quick Reference Handbook
    Role: Provides pilots with immediate, step-by-step procedures for abnormal or emergency situations.

  • MRO – Maintenance, Repair, and Overhaul
    Role: Refers to the scheduled and unscheduled activities ensuring an aircraft remains airworthy.

  • SSR – Secondary Surveillance Radar
    Role: Works with transponders to provide ATC with aircraft identification and altitude data.

  • AVSEC – Aviation Security
    Role: Encompasses measures and protocols designed to protect aviation infrastructure, aircraft, and passengers from security threats.

  • MEL – Minimum Equipment List
    Role: A list specifying the minimum equipment required for an aircraft to be airworthy.

  • MMEL – Master Minimum Equipment List
    Role: A manufacturer’s comprehensive list from which an operator’s MEL is derived.


7. Operational Environment & Terminology

  • VMC – Visual Meteorological Conditions
    Role: Weather conditions allowing flight primarily by visual reference.

  • IMC – Instrument Meteorological Conditions
    Role: Conditions where reduced visibility necessitates reliance on flight instruments.

  • MEA – Minimum Enroute Altitude
    Role: The lowest altitude ensuring obstacle clearance and navigational aid signal coverage along a route.

  • MVA – Minimum Vectoring Altitude
    Role: The lowest altitude at which ATC can safely provide radar vectors.

  • TA – Traffic Advisory
    Role: Alerts generated (often by TCAS) that warn pilots of nearby traffic.

  • RA – Resolution Advisory
    Role: Immediate instructions from TCAS to climb or descend to avoid a collision.

  • CDR – Commander
    Role: The pilot in command responsible for overall flight decisions.

  • FO – First Officer
    Role: The co-pilot assisting the commander and capable of assuming command if needed.


8. Additional Operational & Performance Abbreviations

  • AFM – Aircraft Flight Manual
    Purpose: The manufacturer’s manual detailing performance data, limitations, and procedures.

  • FCOM – Flight Crew Operating Manual
    Purpose: A pilot-oriented document with aircraft-specific procedures and performance charts.

  • QAR – Quick Access Recorder
    Purpose: Records flight data for rapid analysis and troubleshooting.

  • SMS – Safety Management System
    Purpose: A structured approach for managing safety risks via policies, procedures, and training.

  • AOG – Aircraft on Ground
    Meaning: Indicates an aircraft is grounded due to technical issues, often causing delays.

  • TBO – Time Between Overhaul
    Purpose: The recommended interval for component or engine overhaul to maintain reliability.

  • OAT – Outside Air Temperature
    Purpose: The ambient air temperature outside the aircraft, used in performance calculations.

  • TAT – Total Air Temperature
    Purpose: The temperature measured on the aircraft accounting for air compression and friction effects.

  • ISA – International Standard Atmosphere
    Purpose: A reference model of atmospheric pressure and temperature used for performance and design.

  • ROC – Rate of Climb
    Meaning: The vertical speed (typically in feet per minute) at which an aircraft ascends.

  • ROD – Rate of Descent
    Meaning: The vertical speed during descent, crucial for approach management.

  • IAS – Indicated Airspeed
    Meaning: The speed read directly from the aircraft’s instruments.

  • CAS – Calibrated Airspeed
    Meaning: Indicated airspeed corrected for instrument and positional errors.

  • TAS – True Airspeed
    Meaning: The actual speed through the air, adjusted for altitude and temperature.

  • GS – Ground Speed
    Meaning: The speed of the aircraft relative to the ground, considering wind effects.

  • VFE – Maximum Flap Extended Speed
    Purpose: The highest speed at which flaps can be deployed safely.

  • VNE – Never Exceed Speed
    Meaning: The maximum speed beyond which the aircraft must not operate to avoid structural damage.

  • VA – Maneuvering Speed
    Meaning: The speed at which full, abrupt control inputs will not overstress the aircraft.


9. Engine & System Performance Parameters

  • FADEC – Full Authority Digital Engine Control
    Purpose: Fully manages engine performance, optimizing fuel efficiency and responsiveness while reducing pilot workload.

  • EPR – Engine Pressure Ratio
    Purpose: A key performance metric comparing exhaust pressure to inlet air pressure.

  • N1 & N2 – Engine Speed Parameters

    • N1: The rotational speed of the engine’s fan or low-pressure compressor.
    • N2: The rotational speed of the high-pressure compressor.
      Context: Critical for monitoring engine performance and health.
  • MCP – Mode Control Panel
    Purpose: The interface through which pilots set and adjust autopilot parameters such as altitude, heading, and speed.


10. Maintenance & Regulatory Directives

  • AD – Airworthiness Directive
    Purpose: A mandatory regulation requiring specific inspections, repairs, or modifications to maintain safe operations.

  • SB – Service Bulletin
    Purpose: Recommendations issued by manufacturers, sometimes leading to mandatory actions via an AD.


11. Emerging Technologies & Modern Aviation Terms

  • ADS-C – Automatic Dependent Surveillance–Contract
    Role: A variant of ADS where aircraft periodically report their position/status via a contractual agreement with ATC—vital for remote airspace.

  • UAS – Unmanned Aircraft System
    Role: The complete system of unmanned aerial vehicles (drones), ground control stations, and data links.

  • sUAS – Small Unmanned Aircraft System
    Role: Refers specifically to smaller drones (often under 55 pounds) that operate under a more lenient regulatory framework.

  • BVLOS – Beyond Visual Line of Sight
    Role: Refers to drone operations conducted beyond the pilot’s unaided visual range.

  • RPAS – Remotely Piloted Aircraft System
    Role: Another term for systems that include remotely controlled aircraft, emphasizing the piloted aspect.

  • UTM – Unmanned Traffic Management
    Role: Systems and procedures developed to safely integrate UAS into the airspace alongside manned aircraft.

  • SESAR – Single European Sky ATM Research
    Role: An initiative to modernize air traffic management in Europe through innovative technologies and procedures.

  • NextGen
    Role: The U.S. Next Generation Air Transportation System initiative aimed at modernizing the national airspace.

  • CDM – Collaborative Decision Making
    Role: A process that integrates all stakeholders (airlines, ATC, airports) to optimize decision-making in air traffic management.

  • SWIM – System Wide Information Management
    Role: A NextGen concept that enables the sharing of information among airspace users for improved situational awareness.

  • CNS – Communication, Navigation, and Surveillance
    Role: An umbrella term for the integrated systems that underpin modern air traffic management.

  • Data Link
    Role: Digital communications (e.g., ACARS, CPDLC) that transmit operational and safety data between aircraft and ground systems.

  • eVTOL – Electric Vertical Take-Off and Landing
    Role: Refers to a new class of electric-powered aircraft designed for urban air mobility with vertical lift capabilities.


12. Miscellaneous & Additional Codes

  • ADF – Automatic Direction Finder
    Role: Works with NDBs to provide directional information to the pilot.

  • HUD – Head-Up Display
    Role: Projects critical flight data into the pilot’s forward field of view, enabling hands-on control with minimal head movement.

  • FMC – Flight Management Computer
    Role: The core component of the FMS that processes navigation data and manages flight plans.

  • FMA – Flight Mode Annunciator
    Role: Indicates active autopilot modes and flight director commands.

  • CTC – Centralized Traffic Control
    Role: A ground-based system used in some airports and terminal airspaces for efficient traffic management.

  • VDF – Voice Data Follower (less common)
    Role: A system or protocol in certain contexts to automatically follow or log voice communications.

  • SLAT – Leading Edge Slat
    Role: Movable aerodynamic surfaces on a wing’s leading edge that improve low-speed performance during takeoff and landing.

  • C-Check, D-Check, etc.
    Meaning: Scheduled maintenance checks (though not “abbreviations” in the strict sense, these terms are ubiquitous in MRO documentation).


13. Additional Operational Concepts & Emerging Use Cases

  • UTP – Unscheduled Technical Problem
    Used in operational dispatch and maintenance logs to identify non-routine issues affecting aircraft readiness.
  • LOSA – Line Operations Safety Audit
    Observational safety program capturing routine flight operations to proactively identify threats and errors.
  • LAT & LONG – Latitude and Longitude
    Geographical coordinates used in flight planning, navigation, and FMS route entry.
  • RAIM – Receiver Autonomous Integrity Monitoring
    A GPS integrity check algorithm to alert the crew if satellite data is unreliable.
  • FOD – Foreign Object Debris
    Refers to any object that could damage aircraft (e.g., tools, stones, birds) on runways or taxiways.

14. ICAO Annexes – Reference Framework

The ICAO Annexes provide the legal and procedural backbone of international aviation. Here are some key examples:

  • Annex 6 – Operation of Aircraft
  • Annex 8 – Airworthiness of Aircraft
  • Annex 11 – Air Traffic Services
  • Annex 14 – Aerodromes

15. External References & Resources

For further reading:

  • ICAO Doc 8400 – Abbreviations and Codes
  • FAA AIM – Aeronautical Information Manual
  • EASA – European Union Aviation Safety Agency – The European counterpart to the FAA. It ensures aviation safety across EU member states by setting regulations, certifying aircraft and parts, and overseeing flight operations.

NOTAMs

 

1. Aerodrome Operations Abbreviations

  • AD – Aerodrome
  • APR – Apron
  • RWY – Runway
  • TWY – Taxiway
  • RAMP – Ramp area
  • PARK – Aircraft parking area
  • TWR – Tower
  • ILS – Instrument Landing System
  • ILS CAT I, II, III – Instrument Landing System, Category I, II, III
  • VOR – VHF Omnidirectional Range
  • DME – Distance Measuring Equipment
  • NDB – Non-Directional Beacon
  • PAPI – Precision Approach Path Indicator
  • RVR – Runway Visual Range
  • ATIS – Automatic Terminal Information Service
  • CLSD – Closed (e.g., runway closed)
  • INOP – Inoperative (e.g., equipment failure)
  • SUSP – Suspended (e.g., temporary suspension of services)
  • CANCEL – Cancellation of NOTAM or restriction
  • TEMP – Temporary (e.g., temporary restriction or closure)
  • WXR – Weather-related NOTAM
  • NOTAM – Notice to Airmen (general term)

2. Air Traffic Control and Airspace Abbreviations

  • CTR – Control Zone
  • CTA – Control Area
  • TMA – Terminal Control Area
  • FIR – Flight Information Region
  • FIR (LIR) – Lower Information Region
  • FIR (UIR) – Upper Information Region
  • TRA – Temporary Restricted Area
  • SUA – Special Use Airspace
  • RAT – Route Availability Warning
  • SFC – Surface (altitude)
  • FL – Flight Level
  • PANS – Procedures for Air Navigation Services
  • ATC – Air Traffic Control
  • ATS – Air Traffic Services
  • GND – Ground operations
  • ALTN – Alternate (e.g., alternate aerodrome)
  • RPL – Runway partially closed

3. Weather and Meteorological Abbreviations

  • METAR – Meteorological Aerodrome Report
  • TAF – Terminal Aerodrome Forecast
  • GAMET – General Aviation Meteorological Information
  • SIGMET – Significant Meteorological Information
  • AIRMET – Aeronautical Meteorological Information
  • QNH – Sea-level pressure setting for altimeter
  • QFE – Aerodrome pressure setting
  • QNE – Standard pressure setting (1013.25 hPa)
  • CAVOK – Ceiling and visibility okay (good weather)
  • VFR – Visual Flight Rules
  • IFR – Instrument Flight Rules
  • RVR – Runway Visual Range
  • WS – Wind Shear
  • ICING – Icing conditions
  • TURB – Turbulence
  • FZ – Freezing (e.g., freezing rain, freezing fog)

4. Navigation Aids and Communications

  • VHF – Very High Frequency
  • HF – High Frequency
  • SATCOM – Satellite Communication
  • AIS – Aeronautical Information Service
  • FIS – Flight Information Service
  • NDB – Non-Directional Beacon
  • VOR – VHF Omnidirectional Range
  • DME – Distance Measuring Equipment
  • ILS – Instrument Landing System
  • GNSS – Global Navigation Satellite System
  • PBN – Performance-Based Navigation
  • LPV – Localizer Performance with Vertical Guidance
  • FMS – Flight Management System
  • AMHS – Aeronautical Message Handling System
  • ACARS – Aircraft Communications Addressing and Reporting System
  • ADS-B – Automatic Dependent Surveillance-Broadcast

5. Flight Restrictions, Temporary Notices, and Hazardous Conditions

  • TFR – Temporary Flight Restriction
  • NOAT – No Air Traffic (area or sector)
  • SUA – Special Use Airspace (restricted)
  • RTA – Route Availability Warning
  • RCL – Reduced Capacity Limitations
  • RPL – Route partially closed
  • RMP – Restricted Area Map
  • SADIS – Satellite Distribution of Information Service
  • EXER – Exercise (e.g., military or special operational exercises)
  • CALLSIGN – ATC callsign for communication
  • SEC – Security-related restriction (e.g., no-fly zone)
  • HAZARDOUS – Hazardous conditions (e.g., volcanic ash, chemical spills)
  • INJURY – Injuries reported (e.g., on ground or during operations)

6. Safety-Related Abbreviations

  • HAZ – Hazardous
  • SMM – Surface Movement Monitoring
  • EXER – Exercise (e.g., military or civil aviation exercises)
  • SFR – Special Flight Rules (for areas with particular operational rules)
  • SMR – Surface Movement Radar
  • RESCUE – Rescue operations (e.g., aircraft or ship rescue missions)
  • SAR – Search and Rescue
  • RCP – Required Communication Performance
  • RNAV – Area Navigation (includes GNSS-based navigation)
  • TSA – Temporary Security Area

7. Aerodrome Services and Equipment

  • FUEL – Fuel availability (e.g., Jet A1, Avgas)
  • LVP – Low Visibility Procedures
  • LTO – Landing and Take-off Operations
  • AMSL – Above Mean Sea Level
  • TAKE-OFF – Take-off runway operation (may be specified as a restriction)
  • DE-ICE – De-icing services
  • RAMP – Ramp and apron (areas designated for aircraft parking and service)

8. Miscellaneous Abbreviations

  • TMA – Terminal Area
  • ATS – Air Traffic Services
  • INOP – Inoperative (equipment)
  • CANCEL – Cancelled NOTAM or restriction
  • INACT – Inactive (services, navaids, or equipment)
  • VMC – Visual Meteorological Conditions
  • IMC – Instrument Meteorological Conditions
  • CALLSIGN – Radio callsign for ATC communications
  • FPL – Flight Plan
  • QNH – Aerodrome altimeter setting
  • AMHS – Aeronautical Message Handling System
  • OPR – Operator (e.g., airline operator)
  • OBST – Obstacle (e.g., building or terrain)

9. Example of a Detailed NOTAM

Here’s an example of a more detailed NOTAM using many of the abbreviations:

 
Q) EGLL/QMRLC/IV/NBO/A/000/999/5122N00123W005 A) EGLL B) 2402201200 C) 2402251800 E) RWY 09L/27R INOP DUE TO MAINT (TEMP). LOW VISIBILITY PROCEDURES IN PLACE. F) CAT II ILS OPERATING AT RWY 09R. PAPI 3 DEGREE NOT AMENDED.
  • Q): Query Prefix and area-specific restriction (London Heathrow, in this case)
  • B): Start time
  • C): End time
  • E): Reason for closure (temporary maintenance and LVP)
  • F): Additional operational note (ILS CAT II operation for a different runway)

10. Additional NOTAM-related Codes

  • ASHTAM – NOTAM related to volcanic ash contamination in the atmosphere.
  • SNOWTAM – Special series NOTAM regarding the presence or removal of snow, ice or slush on aerodrome surfaces.
  • PIB – Pre-flight Information Bulletin, a compilation of current NOTAMs for a specific route or aerodrome.
  • TRIGGER NOTAM – Short-term NOTAM alerting operators to changes in AIP or procedures.
  • CHECKLIST – NOTAM that provides a reference of all active NOTAMs for a particular location.

11. Example Breakdown with Explanations

NOTAM:
Q) LIMM/QMRLC/IV/NBO/A/000/999/4512N00903E005
A) LIMC
B) 2504010600 C) 2504011200
E) RWY 35L CLSD DUE TO WORK IN PROGRESS. RWY 35R AVBL. LDG/TKOF ON 35L PROHIBITED.

  • Q): ICAO location and NOTAM subject/type (RWY closure)
  • A): Aerodrome location (LIMC - Milan Malpensa)
  • B): Start of validity
  • C): End of validity
  • E): Operational detail (Runway closed for work; landing/take-off prohibited)

12. Resources and References

Based on ICAO Annex 15, DOC 8126, and EAD (European AIS Database) standards.