#ABCDEFGHIJKLMNOPQRSTUVWXYZ
| 1090 ES | 1090 MHz Extended Squitter |
| 3D, 4D | 3 or 4 Dimension |
| 2EP | Two Eyes Principle |
| 4EP | Four Eyes Principle |
| 5LNC | Five Letter Naming Codes |
| AA | Approved Agency |
| AAC | a) Airline Administrative Control b) Aeronautical Administrative Communication |
| AAS | Automation and ATM System |
| ABI | Advanced Boundary Information Message |
| ASN.1 ACARS | Abstract Syntax Notation One – ACARS |
| AC | Advisory Circular |
| ACARE | Advisory Council for Aeronautics Research in Europe |
| ACAS | Airborne Collision Avoidance System |
| ACC | Area Control Centre |
| ACE | ATM and CNS System Engineering (an EEC Centre of Expertise) |
| ACF | ACARS Convergence Function |
| ACG | ATM/CNS Consultancy Group |
| ACI | Airports Council International |
| ACID | Aircraft Identification |
| ACK | Acknowledgement |
| AD | Application Description |
| ADDI | Automated Digital Data Interchange |
| ADEP | Airport of Departure |
| ADES | Airport of Destination |
| ADI | Aggregate Demand Indicators |
| ADLP | Airborne Data Link Processor |
| ADNS | ARINC Data Network Service |
| ADOP | ICAO Aerodrome Design and Operations Panel |
| ADPCM | Adaptive Differential Pulse Code Modulation |
| ADS | Automatic Dependent Surveillance |
| ADS-B | Automatic Dependent Surveillance Broadcast |
| ADS-C | Automatic Dependence Surveillance Contract |
| ADSF | Automatic Dependent Surveillance Function |
| ADSU | Automatic Dependent Surveillance Unit or ADS Unit |
| AECMA | Association Européenne des Constructeurs de Matériel Aérospatial (European Association of Aerospace Industries) |
| AEEC | Airlines Electronic Engineering Committee |
| AELTS | ICAO’s Aviation English Language Test Service |
| AENA | Aeropuertos Españoles y Navegación Aérea (Spanish Airports and Air Navigation) |
| AES | Aircraft Earth Station |
| AFC | ATC Frequency Change service |
| AFE | Africa East |
| AFIS | Automated Flight Inspection System |
| AFL | Actual Flight Level |
| AFM | Africa and Middle East |
| AFP | Air Traffic Control Flight Plan Proposal |
| AFS | Aeronautical Fixed Service |
| AFTN | Aeronautical Fixed Telecommunication Network |
| AGAS | Action Group for ATM Safety |
| AGL | Above Ground Level |
| AIDC | ATC Interfacility Data Communications |
| AIDS | Acquired Immune Deficiency Syndrome |
| AIP | Aeronautical Information Publication |
| AIRMET | Airmen’s Meteorological Information |
| AIS | Aeronautical Information Service(s) |
| AKN | Acknowledgement |
| AL | Alerting Service |
| AMA | Americas |
| AMC | Airspace Management Cell |
| AMJ | Advisory Material-Joint |
| AMS | Apron Management Services |
| AMSS | Aeronautical Mobile Satellite Service |
| AMWG | Airspace Management Working Group |
| ANACNA | Associazione Nazionale Assistenti e Controllori della Navigazione Aerea |
| ANC | ICAO Air Navigation Commission |
| AN-Conf/11 | Eleventh Air Navigation Conference |
| ANM | ATFM Notification Message |
| ANP | Actual Navigation Performance |
| ANS | Air Navigation Services |
| ANSP | Air Navigation Service Provider |
| ANT | Air Navigation Team |
| AO | Aircraft Operator |
| AOC | a) Aeronautical Operational Control b) Aircraft Operational Control c) Aircraft Operations Centre d) Airline Operational Communications System e) Airline Operations Centre |
| AOPG | Aerodrome Operations Group |
| AOT | Aerodrome Operations Team |
| APANPIRG | ASIA/PAC Air Navigation Planning and Implementation Regional Group |
| APC | a) Aeronautical Passenger Communications b) Aeronautical Public Correspondence |
| APDSG | ATM Procedures Development Sub-Group |
| APIWP | Approach Intercept Waypoint |
| APL | Abbreviated Flight Plan |
| APM | Associate Professional Membership |
| APP | Approach Control |
| APRs | Automatic Position Reports |
| APT | Airport Throughput (an EEC Research Area) |
| APW | Area Proximity Warning |
| ARCW | ADS Route Conformance Warning |
| ARINC | Aeronautical Radio Incorporation |
| ARO | ATS Reporting Office |
| ARR | Arrival message |
| ARTAS | a) Air Traffic Management Surveillance Tracker and Server System b) ATC Radar Tracker and Server |
| ARTCC | Air Route Traffic Control Centre |
| AS | Airborne Surveillance |
| ASA | Aircraft Surveillance Applications |
| ASAS | Airborne Separation Assistance System |
| ASAS TN | Airborne Separation Assistance System Thematic Network |
| ASBU | Airspace Block Upgrades |
| ASD | Air Situation Display |
| ASDE-X | Airport Surface Detection Equipment Model X |
| ASECNA | Agency for the Security of Aerial Navigation in Africa and Madagascar |
| ASM | Airspace Management |
| A-SMGCS | Advanced Surface Movement Guidance and Control System |
| ASMT | Air Traffic Control Safety Monitoring Tool |
| ASN.1 | Abstract Syntax Notation One |
| ASP | Asia and Pacific |
| ASPA-S&M | Enhanced Sequencing and Merging Operations |
| ASTERIX | All Purpose STructured Eurocontrol suRveillance Information EXchange |
| ATA | Air Transport Association |
| ATAR | Automatic Air Reporting |
| ATC | Air Traffic Control, Air Traffic Control Domain |
| ATCC | Air Traffic Control Centre |
| ATCComm | Air Traffic Control Communications Systems (Hardware & Software) |
| ATCEUC | Air Traffic Controllers European Unions Coordination |
| ATCO | Air Traffic Control Officer |
| ATCS | Air Traffic Control Services |
| ATD | Along-Track Distance |
| ATFM | Air Traffic Flow Management |
| ATIS | a) Air Traffic Information Service b) Airport Terminal Information Service c) Automated Terminal Information Service |
| ATLAS | Australian Transition to Satellite Technology |
| ATM | Air Traffic Management |
| ATMOPSP | ICAO ATM Operations Panel |
| ATMRPP | ICAO Air Traffic Management Requirements and Performance Panel |
| ATN | Aeronautical Telecommunications Network |
| ATO | Actual Time Over |
| ATRK | Along-Track Error |
| ATS | Air Traffic Service(s) |
| ATSA-AIRB | Enhanced traffic situational awareness during flight operations |
| ATSA-S&A | Enhanced visual acquisition for see & avoid |
| ATSA-SURF | Enhanced traffic situational awareness on the airport surface |
| ATSA-SVA | Enhanced successive visual approaches |
| ATSAW | Airborne Traffic Situation Awareness |
| ATSC | Air Traffic Services Communication |
| ATS-PM | ICAO Doc 9426 – Air Traffic Services Planning Manual |
| ATSU | Air Traffic Service Unit |
| AUP | Airspace Use Plan |
| AUSEP | Australian RNAV Standard |
| AVPAC | Aviation VHF Packet Communications |
| BDS | Comm-B Data Store |
| BER | Basic Encoding Rules |
| BRL | Bearing Range Line |
| B-RNAV | Basic Area Navigation |
| C/A | Course Acquisition Code |
| C/I | Carrier-to-Interference Ratio |
| C/N | Carrier-to-Noise Ratio |
| CAA | a) Civil Aviation Administration b) Civil Aviation Authority |
| CAASD | Centre for Advanced Aviation System Development (The MITRE Corporation) |
| CADF | Centralised Airspace Data Processing Function |
| CANSO | Civil Air Navigation Services Organisation |
| CAR | Caribbean |
| CASA | Civil Aviation Safety Authority (Australia) |
| CASCADE | Co-Operative ATS through Surveillance & Communication Applications Deployed in ECAC |
| CAT | Data Category |
| CATMAC | Co-operative Air Traffic Management Concept |
| CBA | a) Cost/Benefit Analysis b) Cross-Border Area |
| CBI | Computer Based Instruction |
| CC | Connection Confirm |
| CCIR | International Radio Consultative Committee |
| CCITT | International Telegraph and Telephone Consultative Committee |
| CCO | Continuous Climb Operations |
| CDA | Continuous Descent Approaches |
| CDI | Course Deviation Indicator |
| CDM | Collaborative Decision Making |
| CDO | Continuous Descent Operations |
| CDR | Conditional Route |
| CDSNs | Conflict Detection Safety Nets |
| CDTI | Cockpit Display of Traffic Information |
| CDTs | Conflict Detection Tools |
| CEATS | Central European Air Traffic Services |
| CEO | Chief Executive Officer |
| CFMU | Central Flow Management Unit (EUROCONTROL, replaced by NMOC) |
| CHI | Computer Human Interface |
| CIB | Controller Intervention Buffer |
| CIC | a) Controller Intervention Capability b) Controller in Charge |
| CIDIN | Common ICAO Data Interchange Network |
| CIMIC | Civil/Military Interface Standing Committee |
| CIP | Convergence and Implementation Plan |
| CIS | a) Critical Incident Stress b) Co-operative Independent Surveillance |
| CISM | Critical Incident Stress Management |
| CLAM | Cleared Level Adherence Monitoring |
| CLNP | Connectionless Network Protocol |
| CM | Context Management |
| CMC | Civil/Military Cooperation |
| CMG | Controller Management Group |
| CMU | a) Communications Management Unit b) Context Management Unit |
| CNS | Communication Navigation and Surveillance |
| CNS/ATM | Communication, Navigation, Surveillance/Air Traffic Management |
| CoE | Centre of Expertise |
| COM | Communications |
| COM/MET/OPS | Communications/Meteorology/Operations |
| Connection | Transport Layer Relationship between peer end-systems. |
| CONUS | Continental United States |
| COTS | Commercial Off-The-Shelf |
| CP | ICAO Communications Panel |
| CPDLC | Controller Pilot Data Link Communications |
| CR | Connection Request |
| CRAM | Conditional Route Availability Message |
| CRC | Cyclic Redundancy Check |
| CRDA | Converging Runway Display Aid |
| CRDS | CEATS Research and Development Simulation Centre |
| CRM | a) C Reference Model b) Collision Risk Modelling c) Crew Resource Management |
| CROPS | Converging Runway Operations |
| CRT | Cathode Ray Tube |
| CSE | Course Setting Error |
| CTA | a) Control Area b) Calculated Time of Arrival |
| CTMO | Centralised Traffic Management Organisation |
| CTs | Controller Tools |
| CW | Carrier Wave |
| CWI | Continuous Wave Interference |
| D, R, P Areas | Danger, Restricted and Prohibited Areas |
| DA/H | Decision Altitude (Height) |
| DAI | Development and Integration (an EEC Centre of Expertise) |
| DARPS | Dynamic Air Route Planning System |
| D-ATIS | Digital Automatic Terminal Information Service |
| dBm | The dBm is the unit of absolute power related to 1 milliwatt |
| DCE | Data Circuit-Terminating Equipment |
| DCIA | Dependent Converging Instrument Approach |
| DCL | Departure Clearance Delivery |
| DCPC | Direct Controller Pilot Communication |
| DDM | Difference Depth of Modulation (ILS) |
| DFDAU | Digital Flight Data Acquisition Unit |
| Dg | Degree |
| DGCA | Director-General Civil Aviation |
| DGNSS | Differential GNSS |
| DGPS | Differential Global Positioning System |
| DIAS | Differential GNSS Instrument Approach System |
| DL | a) Data Link b) Downlink |
| DLAC | Data Link Applications Coding |
| DLORT | FAA Data Link Operational Requirements Team |
| DME | Distance Measuring Equipment |
| DO | Document |
| DOP | Dilution of Precision |
| DOTS | Dynamic Ocean Tracking System |
| DP | Deputy President |
| DPF | Data Processing Function |
| DPSK | Differential Phase Shift Keying |
| DR | Disconnect Request |
| DRMS | Distance Route Mean Square |
| DT | Data |
| DTF | Data Test Facility |
| E. I. | Employee Involvement |
| EAG EUROCONTROL | European ATFM Group |
| EANPG ICAO | European Air Navigation Planning Group |
| EAP | Employee Assistant Programme |
| EASA | European Aviation Safety Agency |
| EASIE | Enhanced ATM and Mode S Implementation in Europe |
| EATCHIP | European Air Traffic Control Harmonisation and Integration Programme |
| EATM | EUROCONTROL Programme for Performance Enhancement in European Air Traffic Management |
| EC | European Commission |
| ECA | European Cockpit Association |
| ECAC | European Civil Aviation Conference |
| ECCG | Experimental Centre Consultation Group |
| EEC | a) European Economic Community b) EUROCONTROL Experimental Centre |
| EET | Estimated Elapsed Time |
| EFAS | Extended Final Approach Segment |
| EFIS | Electronic Flight Information System |
| EFR | Electronic Flight Rules |
| EGOA | Enhanced General Aviation Operations |
| EHS | Electromagnetic Hyper Sensitivity |
| EMC | Electromagnetic Compatibility |
| EMF | Electro Magnetic Fields |
| EMI | Electromagnetic Interference |
| ENAV | Italian company for Air Navigation Services |
| ENRI | Electronic Navigation Research Institute |
| ER | Error |
| ERN | Earth Referenced Navigation |
| ERP | Effective Radiated Power |
| ESA | European Space Agency |
| ESARR | EUROCONTROL Safety Regulatory Requirements |
| ESOPS | Employee Share Option Schemes |
| EST | Estimate message |
| ETA | Estimated Time of Arrival |
| ETB | Estimated Time at Boundary |
| ETD | Estimated Time of Departure |
| ETN | Estimated Time of Entry |
| ETO | Estimated Time Over |
| ETODA | Estimated Time Over Deviation Alert |
| EU | European Union |
| EUC | Europe Central |
| EUR | Europe |
| EURATN | European ATN |
| EURET | European Transport |
| EUROCAE | European Organisation for Civil Aviation Equipment |
| EUROCONTROL | European Organisation for the Safety of Air Navigation |
| EUW | Europe West |
| EVP | Executive Vice President |
| EVP AFM | Executive Vice President Africa and Middle East |
| EVP AMA | Executive Vice President Americas |
| EVP ASP | Executive Vice President Asia and Pacific |
| EVP EUR | Executive Vice President Europe |
| EVPF | Executive Vice President Finance |
| EVPP | Executive Vice President Professional |
| EVPT | Executive Vice President Technical |
| FAA | Federal Aviation Administration |
| FAB | Functional Airspace Blocks |
| FAF | Final Approach Fix |
| FANS | ICAO Future Air Navigation Systems |
| FAR | Federal Aviation Regulation |
| FAS | Final Approach Segment |
| FAST | Future ATM Systems Team |
| FDI | Fault Detection and Isolation |
| FDP | Flight Data Processing |
| FDPS | Flight Data Processing System |
| FDR | Flight Data Record |
| FEC | Forward Error Correction |
| FF-ICE | Flight and Flow – Information for a Collaborative Environment |
| FGCC | Federal Geodetic Control Committee |
| FIFO | First In – First Out |
| FIIG | Federation of International Institutions of a semi-official or private nature (Geneva) |
| FIR | Flight Information Region |
| FIS | Flight Information Services |
| FIS-B | Flight Information Services Broadcast |
| FL | Flight Level, unit of altitude (expressed in 100’s of feet) |
| FLID | Flight Identification |
| FLAS | Flight Level Allocation Scheme |
| FLTOPSP | ICAO Flight Operations Panel |
| FM | Frequency Modulation |
| FMC | Flight Management Computer |
| FMD | Flow Management Division (CFMU) |
| FMEA | Failure Mode Effects Analysis |
| FMP | Flow Management Position |
| FMS | Flight Management System |
| FMU | Flow Management Unit |
| FOM | Figure of Merit |
| FPA | Flight Path Angle |
| FPD | Flight Plan Data |
| FPL | Flight-Plan |
| FPPS | Flight Plan Processing System |
| FRA | Free Route Airspace |
| FRAC | Free Route Airspace Concept |
| FRAP | Free Route Airspace Project |
| FRMS | Fatigue Risk Management Systems |
| FRN | Field Reference Number |
| FS | Functional Statement |
| FSMP | Frequency Spectrum Management Panel |
| FSPEC | Field Specification |
| FTE | Flight Technical Error |
| FTI | FUA Temporary Instruction |
| FTS | Fast-time Simulation |
| FUA | Flexible Use of Airspace |
| FX | Field Extension Indicator |
| GA | General Aviation |
| GADS | Generic Aircraft Display Systems |
| GAIT | Ground-based Augmentation and Integrity Technique |
| GAT | General Air Traffic |
| GDLP | Ground Data Link Processor |
| GDOP | Geometric Dilution of Position |
| GEO | Geostationary |
| GES | Ground Earth Station |
| GIC | GNSS Integrity Channel |
| GICB | Ground-initiated Comm-B |
| GIRU | Ground Interrogator Receiver Unit |
| GLONASS | Global Navigation Satellite System (Russian Federation) |
| GM | Guidance Material |
| GNSS | Global Navigation Satellite System(s) |
| GNSS PSG EUROCONTROL | GNSS Programme Steering Group |
| GOS | Grade of Service |
| GOSIP | Government Open Systems Interconnection Profile |
| GPIWP | Glide Path Intercept Waypoint |
| GPS | Global Positioning System |
| GPWS | Ground Proximity Warning System |
| GRAS | Ground-based Regional Augmentation System |
| GREPECAS | Caribbean/South American Planning and Implementation Regional Group |
| GS | Ground Speed |
| GWS | Graphic Weather Service |
| HALE | High Altitude Long Endurance |
| HARN | High Accuracy Reference Network |
| HAT | Height Above Touchdown |
| HCI | Human Computer Interface |
| HDLC | High-Level Data Link Control |
| HDOP | Horizontal Dilution of Precision |
| HELI | Helicopter Operations |
| HEO | Highly Elliptical Orbit |
| HF | High Frequency |
| HFS | Human Factors Specialist |
| HIV | Human Immune-deficiency Virus |
| HMI | Human Machine Interface |
| HPF | Horizontal Position Fix Error |
| HRM | Human Resource Management |
| HRT EUROCONTROL | Human Resources Team |
| HRT TFG EUROCONTROL | Human Resources Team Training Focus Group |
| HRT/HFSG EUROCONTROL | Human Resources Team Human Factors Work Group |
| HSI | Horizontal Situation Indicator |
| HUPER | Human Performance |
| IA5 | International Alphabet #5 |
| IAF | Initial Approach Fix |
| IAG | International Aviation Group |
| IAIN | International Association of Institutes of Navigation |
| IANS | Institute of Air Navigation Services |
| IAP | Instrument Approach Procedure |
| IAS | Indicated Airspeed |
| IAS TF A /B | Implementation of Airspace Strategy Task Force A & B |
| IATA | International Air Transport Association |
| ICAEA | International Civil Aviation English Association |
| ICAO | International Civil Aviation Organisation |
| ICB | Industry Consultation Body (European Commission) |
| ICCAIA | International Coordinating Council of Aerospace Industries Associations |
| ICD | Interface Control Document |
| ICD GPS-200B- PR | NAVSTAR GPS Space Segment/Navigation User Interface Control |
| ICISF | International Critical Incident Stress Foundation |
| ID | a) Identifier b) Identification |
| IFALPA | International Federation of Airline Pilots’ Associations |
| IFATCA | International Federation of Air Traffic Controllers’ Associations |
| IFATSEA | International Federation of Air Traffic Safety Electronics Associations |
| IFER | In-Flight Emergency Response |
| IFPP | ICAO Instrument Flight Procedures Panel |
| IFPS | Integrated Initial Flight Plan Processing System |
| IFR | Instrumental Flight Rules |
| IFRB | International Frequency Registration Board |
| IHB | Information Handbook |
| ILO | International Labour Organisation |
| ILS | Instrument Landing System |
| IM | Information Material |
| IMAWP | Initial Missed Approach Waypoint |
| IMC | Instrument Meteorological Conditions |
| IN | Information Need |
| INMARSAT | International Maritime Satellite Organisation |
| INO | Innovative Research (an EEC Research Area) |
| INS | a) Inertial Navigation System b) Insert |
| IOACG | Informal Indian Ocean Air Traffic Services Coordinating Group |
| IOC | Initial Operational Capability |
| IOD | GPS Issue of Data |
| ION | Institute of Navigation |
| IP | Internetwork Protocol |
| IRS | Inertial Reference System |
| ISDN | Integrated Services Digital Network |
| ISO | International Standards Organisation |
| ISPACG | Informal South Pacific ATS Co-Ordination Group |
| ITF | International Transport Workers’ Federation |
| ITU | International Telecommunication Union |
| ITWS | Integrated Terminal Weather Service |
| IWP | Interim Working Party |
| JC | Just Culture |
| JCAB | Japan Civil Aviation Bureau |
| JPB | Joint Programme Board |
| KPI | Key Performance Indicator |
| kt | Knot: NM/hour, unit of speed |
| LADGNSS | Local Area Differential GNSS |
| LAN | Local Area Network |
| LAT/LONG | Latitude / Longitude |
| LEN | Length Indicator |
| LEO | Low Earth Orbit |
| LOEU | Liaison Officer European Union |
| LO ECTL | Liaison Officer EUROCONTROL |
| LOIG | Liaison Officer to International Organisations in Geneva |
| LOSA | Line Operations Safety Audit |
| LPC | Linear Predictive Coding |
| LPO | Lone Person Operation |
| LPRI | ICAO Language Proficiency Requirements Implementation |
| LRU | Line Replaceable Unit |
| LSB | Least Significant Bit |
| LVA | Large Vertical Aperture |
| LVO | Low Visibility Operations |
| MA | Member Association |
| MADAP | Maastricht Automated Data Processing and Display System |
| MAEVA | Master ATM European Validation Plan |
| MALE | Medium Altitude Long Endurance |
| MAP | Missed Approach Point |
| MAPt | Missed Approach Point |
| MASPS | Minimum Aviation System Performance Standards |
| MB | Message, Comm B |
| MBI | Message Block Identifier |
| MBS | Model Based Simulations |
| MCDU | Multifunction Control Display Unit |
| MET | Meteorological |
| METP | ICAO Meteorology Panel |
| MFF | Mediterranean Free Flight Programme |
| MID | Middle East |
| MIFR | Master International Frequency Registration |
| MLS | Microwave Landing System |
| MLAT | Multilateration |
| MMI | Man-Machine Interface |
| MNC | Multi -National Corporations |
| MNPS | Minimum Navigation Performance Specification |
| MNT | Mach Number Technique |
| MOC | Mean of Compliance |
| MODE S | Mode Select Transponder |
| Mode S PSG | Mode S Programme Steering Group |
| MONA | Monitoring Aids |
| MOPS | Minimum Operating Performance Standards |
| MRT | Multi-Radar Tracking |
| MRT-VU | Multi-Radar Tracking using Variable Update |
| MRVA | Minimum Radar Vector Altitude |
| MSAW | Minimum Safe Altitude Warning |
| MSB | Most Significant Bit |
| MSSP | Mobile Satellite Service Provider |
| MSE | Mean Square Error |
| MSK | Minimum Shift Keying |
| MSP | a) Mode S Specific Protocolb) Multi Sector Planning |
| MSSR | Monopulse Secondary Surveillance Radar |
| MTBA | Mean Time Between Alarm |
| MTBF | Mean Time Between Failures |
| MTBO | Mean Time Between Outage |
| MTBW | Mean Time Between Warning |
| MTCA | Medium Term Conflict Alert |
| MTCD | Medium Term Conflict Detection |
| MTD | Moving Target Detection |
| MTN | MEGA Transport Network |
| MTSAT | Multi-Functional Transport Satellite |
| MTTR | Mean Time to Restore |
| MU | Management Unit |
| MWARA | Major World Air Route Area |
| NA | Not Applicable |
| NACK | Negative Acknowledgement |
| NAD | North American Datum |
| NADIN | National Airspace Data Interchange Network |
| NASA | National Space Agency |
| NAT | North Atlantic |
| NAT ADSG | North Atlantic Automatic Dependent Surveillance Development Group |
| NAT ATS | North Atlantic Air Traffic Services |
| NATO | North Atlantic Treaty Organisation |
| NATSPG ICAO | North Atlantic Systems Planning Group |
| NAVAID | Navigational Aid |
| NAVD | North American Vertical Datum |
| NCA | North and Central America |
| NCD | Network Capacity and Demand Management (an EEC Research Area) |
| NDA | Next ATC Data Authority as authorised by the current ATC Data Authority |
| NGRS | National Geodetic Reference System |
| NGS | National Geodetic Survey |
| NIST | National Institute of Standards and Technology |
| NM | Nautical Mile, unit of distance (1852 metres) |
| NMOC | Network Manager Operations Centre (EUROCONTROL, previously CFMU) |
| NOPAC | North Pacific |
| NOSS | Normal Operations Safety Survey |
| NOTAM | Notice to Airmen |
| NPDU | Network Protocol Data Unit |
| NSC | Network Service Centre |
| NSDU | Network Service Data Unit |
| NSP | ICAO Navigation Systems Panel |
| NUAC | Nordic Upper Air Centre |
| NUP II | North European Update Programme Phase II |
| O.R. | Operational Requirement |
| OAS | Oceanic Automation System |
| OAT | Operational Air Traffic |
| OCA | Oceanic Control Area |
| OCM | Oceanic Clearance Message |
| OCVM | Operational Concept Validation Methodology |
| OCVSD | Operational Concept Validation Strategy Document |
| ODAPS | Oceanic Display and Planning System |
| ODF | Oceanic Development Facility (FAA Technical Centre) |
| ODIAC | Operational development of Integrated Surveillance & Air/Ground Data Communications |
| ODL | Oceanic Data Link |
| OJT | On-The-Job-Training |
| OLDI | On-line Data Interchange |
| Op | Operational |
| OP SUP | Operational Supervisor |
| OPD | Optimized Profile Descents |
| OPMT | Operations Planning Management Team |
| OPS | a) Operationsb) Operational Services (an EEC Centre of Expertise) |
| ORI | Orientation |
| OSED | Operational Services and Environment Description |
| OSI | a) Open System Interfaceb) Open Systems Interconnection |
| OSST | FAA Oceanic Separation Standards Team |
| OTC | Overseas Telecommunications Company |
| PAC | Pacific |
| PACOTS | Pacific Organized Track System |
| PANS-ABC | Procedures for Air Navigation Services – Abbreviations and Codes (ICAO Doc 8400) |
| PANS-AERO | Procedures for Air Navigation Services – Aerodromes (ICAO Doc 9981) |
| PANS-ATM | Procedures for Air Navigation Services – Air Traffic Management(ICAO Doc 4444) |
| PANS-RAC | Procedures for Air Navigation Services – RAC (now PANS-ATM) |
| PANS-OPS | Procedures for Air Navigation Services – Aircraft Operations (ICAO Doc 8168) |
| PANS-TRG | Procedures for Air Navigation Services – Training (ICAO Doc 9868) |
| PBN | Performance Based Navigation |
| PC | Provisional Council |
| PCA | Prior Co-ordination Airspace |
| PCFL | Pre-cleared Flight Level |
| PCM | Pulse Code Modulation |
| P-Code | Precision Code |
| PCX | President and Chief Executive Officer |
| PDC | Pre-Departure Clearance |
| PDOP | Position Dilution of Precision |
| PEDI | Planning, Education, Demonstration, and Implementation |
| PER | Packed Encoding Rules |
| PET | Pacific Engineering Trials |
| PF | Position Fix Error |
| PFE | Path Following Error |
| PFL | Planned Flight Level |
| PHARE | Programme for Harmonised ATM Research in EUROCONTROL |
| PI | Performance Indicators |
| PIAC | Peak Instantaneous Aircraft Count |
| PM | Policy Material |
| POWG | Permanent Office Working Group |
| PPL | Private Pilot Licence |
| PPM | Provisional Policy Material |
| PPS | Precise Positioning Service |
| PRB | Performance Review Board |
| PRC | Performance Review Commission |
| PRN | Pseudorandom Number |
| PRU | Performance Review Units (EUROCONTROL) |
| PSR | Primary Surveillance Radar |
| PSTN | Public Switched Telecommunications Network |
| PTLP | ICAO Personnel Training and Licensing Panel |
| PWP | Pilot Working Position |
| QFE | Atmospheric Pressure at Aerodrome Elevations or at Runway Threshold |
| QMS | Quality management systems |
| QNH | Altimeter Sub-scale Setting to obtain Elevation when of the Ground |
| QOS | Quality-Of-Service |
| R&D | Research and Development |
| R/T | a) Radio Transmissionb) Radio Telephony |
| RA | Resolution Advisory |
| RAD | Material relating to the provision of radar services |
| RAN | Regional Air Navigation (Meeting) |
| RCA | Reduced Co-ordination Airspace |
| RCF | Radio Communication Failure |
| RCMS | Route Conformance Monitoring System |
| RDA | Route Deviation Alert |
| RDARA | Regional and Domestic Air Route Area. |
| RDE-FG | Radar Data Exchange – Focus Group |
| RDF | Radar Data Function |
| RDP | Radar Data Processing |
| RDPC | Radar Data Processing Chain |
| RDPS | Radar Data Processing System |
| RDT&D | Research, Development, Trials and Demonstrations |
| RE | Reserved Expansion Indicator |
| RECAT | Recategorization (of aircraft for wake turbulence) |
| REM | Rapid Eye Movement |
| REP | Field Repetition Indicator |
| RF | Radius to Fix (method of turn) |
| RFG | Requirements Focus Group |
| RFI | Radio Frequency Interference |
| RFP | Request for Proposal |
| RGS | Remote Ground Station |
| RHCP | Right-Hand-Circular Polarised |
| RLAT | Reduced Lateral Separation Minima |
| RLONG | Reduced Longitudinal Separation Minima |
| RMM | Remote Maintenance Monitoring |
| RNAV | Area Navigation |
| RNAV Route | Area Navigation Route |
| RNP | Required Navigation Performance |
| RNP GM | Guidance Material for Required Navigation Performance |
| RPA | Remotely Piloted Aircraft |
| RPAS | Remotely Piloted Aircraft System |
| RPASP | ICAO Remotely Piloted Aircraft Systems Panel |
| RPL | Repetitive Flight-Plan |
| RPV | Remotely Piloted Vehicle |
| RRC | Range Rate Correction |
| RSP | Required Surveillance Performance |
| RSS | Root-sum-square |
| RTA | Required Time of Arrival |
| RTCA | Radio Technical Commission for Aeronautics |
| RTCM | Radio Technical Commission for Maritime |
| RTF | Radiotelephony |
| RTS | Real-time Simulation |
| RVSM | Reduced Vertical Separation Minima |
| RWEWP | Runway End Waypoint |
| RWIWP | Runway Intercept Waypoint |
| RWY | Runway |
| RWSL | Runway Status Lights |
| s | second, unit of time |
| SA | a) Selective Availability b) Situational Awareness |
| SAC | System Area Code |
| SAE | Society of Automotive Engineers |
| SAGE | The Safety Awareness Group at the EEC |
| SAM | a) Safety Assessment Methodologyb) South America |
| SAR | Search and Rescue |
| SARPs | Standards and Recommended Practices (ICAO) |
| SAS | Safety, Analysis, and Scientific (an EEC Centre of Expertise) |
| SASP | ICAO Separation and Airspace Safety Panel |
| SATCOM | Satellite Communication(s) |
| SBC | Sub-Band Coding |
| SBU | Separate Business Units |
| SC | a) Special Committeeb) Standing Committee |
| SCIA | Simultaneous Converging Instrument Approaches |
| SDM | Sum Depth of Modulation (ILS) |
| SDPS | Surveillance Data Processing System |
| SEE | Society, Environment, Economics (an EEC Research Area) |
| SELCAL | Selective Call |
| SEP | Policy on Separation Standards |
| SES | Single European Sky |
| SESAR | Single European Sky ATM Research |
| SFM | Simulation Facility Management (an EEC Centre of Expertise) |
| SG | Study Group |
| SIC | System Identification Code |
| SID | Standard Instrument Departure |
| SIGMET | Significant Meteorological Information |
| SIMOPS | Simulation Operations |
| SIRO | Simultaneous Intersecting Runway Operations |
| SITA | Société Internationale de Télécommunications Aéronautiques |
| SITF | Study and Implementation Task Force |
| SLM | Standard Length Message |
| SLOP | Standard Lateral Offset Procedures |
| SM | Scale Marker |
| SMC | System Management and Communication |
| SMF | Separation Monitoring Function |
| SMGCS | Surface Movement Guidance and Control System |
| SMP | ICAO Safety Management Panel |
| SMR | Surface Movement Radar |
| SMS | a) Safety Management Systemb) Surface Movement System |
| SOIT | FAA Satellite Operations Implementation Team |
| SP | a) Special Purpose Indicatorb) ICAO Surveillance Panel |
| SPF | Strategic Performance Framework |
| SPI | Special Position Identification |
| SPO | Single Person Operations |
| SPR | Safety and Performance Requirement |
| SPS | Standard Positioning Service |
| SPT | Strip Printer |
| SRA | Strategic Research Agenda |
| SRC EUROCONTROL | Safety Regulation Commission |
| SRDP | Safety Research and Development Plan |
| SRE | Slant Range Error |
| SSC | Significant Safety Concern (ICAO USOAP CMA) |
| SSP | Sector Safety and Productivity (an EEC Research Area) |
| SSR | Secondary Surveillance Radar |
| SSRP | Strategic Safety Research Plan |
| SSWG | System Support Working Group |
| STAR | a) Standard Instrument Arrival (Route) b) Standard Arrival Route |
| STC | Supplementary Type Certification |
| STCA | Short Term Conflict Alert |
| SUR-T | Surveillance Team (EATM) |
| SVC | System View Cell |
| S-VFR | Special-VFR |
| SWIM | System-Wide Information Management |
| TA mode | Traffic Advisory mode |
| TACAN | Tactical Air Navigation |
| TAG | Tactical Action Group |
| TAS | True Airspeed |
| TAWS | Terrain Awareness and Warning System |
| TBA | To be Announced |
| TCAS | a) Traffic Collision Avoidance System b) Traffic Alert and Collision Avoidance System |
| TCH | Threshold Crossing Height |
| TCP | Transport Control Protocol |
| TCP/IP | Transmission Control Protocol/Internetwork Protocol |
| TCWP | Threshold Crossing Waypoint |
| TDLS | Tower Data Link System |
| TDM | Track Definition Message |
| TDWR | Terminal Doppler Weather Radar |
| TEM | Threat and Error Management |
| TIBA | Traffic Information Broadcast (by aircraft) |
| TIS | Traffic Information Service |
| TIS-B | Traffic Information Service Broadcast |
| TL | Transition Level |
| TLS | Target Level of Safety |
| TMA | a) Terminal Control Area b) Terminal Manoeuvring Area |
| TNAV | Time Navigation |
| TOBT | Target Off Block Time |
| TP | Turn Point |
| TP4 | Transport Protocol Class 4 |
| TPC | Technical Policy Coordinator |
| TPDU | Transport Protocol Data Unit |
| TPM | IFATCA Technical and Professional Manual |
| TPSec | IFATCA Technical and Professional Secretary |
| TQM | Total Quality Management |
| TRA | Temporary Reserved Area |
| TRM | Team Resource Management |
| TRS | Transmission message |
| TSA | Temporary Segregated Area |
| TSAP-ID | Transport Service Access Point Identifier |
| TSE | Total System Error Generic |
| TSO | Technical Standard Order |
| TWDL | Two-Way Data Link Communication |
| TWIP | Terminal Weather Information for Pilots |
| TWP | Technical Work Programme of the Organisation in the Air Navigation Field |
| TWPC | Two-Way Pilot Controller |
| TWR | Aerodrome Control Tower |
| UA | Unmanned Aircraft |
| UAC | Upper Area Control Centre |
| UAP | a) Upper Airspace Project b) User Application Profile |
| UAS | Unmanned Aircraft Systems |
| UASAG | ICAO Unmanned Aerial Systems Advisory Group |
| UAT | Universal Access Transmitter |
| UAV | a) Uniform Annual Values b) Unmanned Aerial Vehicle |
| UCAR | Unmanned Combat Armed Rotorcraft |
| UCAV | Unmanned Combat Aerial Vehicle |
| UDPP | User Driven Prioritization Process |
| UDRE | User Differential Range Error |
| UN | United Nations |
| UNDP | United Nations Development Programme |
| URA | User Range Accuracy |
| UTC | Co-ordinated Universal Time |
| UUP | Updated Airspace Use Plan |
| VDEV | Vertical Deviation |
| VDL | VHF Data Link |
| VDOP | Vertical Dilution of Precision |
| VDR | a) VHF Data Radio b) Validation Data Repository |
| VDT | Video Display Terminal |
| VDU | Visual Display Unit |
| VFR | Visual Flight Rules |
| VGH | Validation Guideline Handbook |
| VHF | Very High Frequency |
| VMC | Visual Meteorological Conditions |
| VNAV | Vertical Navigation |
| VOR | VHF Omnidirectional Radio Range |
| VP | Vertical Profile |
| VPAE | Vertical Profile Angle Error |
| VPF | Vertical Position Fix Error |
| VPIP | Vertical Profile Intercept Point |
| VSM | Vertical Separation Minimum |
| VSWR | Voltage Standing Wave Ratio |
| W/E | Warning/Error Condition |
| W/P, WP | Waypoint |
| WA | Wind Angle |
| WADGNSS | Wide Area Differential GNSS |
| WAN | Wide Area Network |
| WCM | World Class Manufacturers |
| WG | Working Group |
| WGS | World Geodetic Survey |
| WGS-84 | World Geodetic System 84 |
| WHO | World Health Organisation |
| WIP | Working Group for Runway Incursion Prevention |
| WP | Working Paper |
| WS | Wind Speed |
| XTK | Cross-Track Distance |
Last Update: October 4, 2023
November 3, 2019 1637 Jean-Francois Lepage TPM