#ABCDEFGHIJKLMNOPQRSTUVWXYZ
Acronym |
Definition |
| 1090 ES | 1090 MHz Extended Squitter |
| 3D, 4D | 3 or 4 Dimension |
| 2EP | Two Eyes Principle: Operations where an ATC unit provides service with one ATCO per sector, but with at least one more equally qualified ATCO on duty and available to assist or provide breaks. |
| 4EP | Four Eyes Principle: Situation where an executive controller is assisted by another appropriately qualified controller monitoring the same area of responsibility as the executive controller. |
| 5LNC | Five Letter Naming Codes |
Acronym |
Definition |
| AA | Approved Agency |
| AAC | a) Airline Administrative Control b) Aeronautical Administrative Communication |
| AAS | a) IFATCA Manual: Advanced Avionics System b) Technical Manual: Advanced Automated System |
| ABI | Advanced Boundary Information Message |
| Abstract Syntax Notation One – (ASN.1) ACARS | A standard definition approach that is consistent with the ISO orientation of the ATN and specific ATN Manual Guidelines a) Aircraft Communications Addressing and Reporting System b) Aircraft Communications and Reporting System c) Aeronautical Radio Incorporation (ARINC) Communications Addressing and Reporting System |
| AC | Advisory Circular |
| ACARE | Advisory Council for Aeronautics Research in Europe |
| ACAS | Airborne Collision Avoidance System |
| ACC | Area Control Centre |
| Accuracy | The degree of conformance between the estimated or measured position and / or velocity and / or time of/at a platform and its true position and/or velocity and the true time. Radio navigation system accuracy is usually presented as a statistical measure of system error and is specified as:
a) Predictable: The accuracy of a position with respect to the geographic or geodetic coordinates of the earth. b) Repeatable: The accuracy with which a user can return to a position whose coordinates have been measured at a previous time with the same navigation system. c) Relative: The accuracy with which a user can determine one position relative to another position regardless of any error in their true positions. In the context of the final approach phase of operation, accuracy may be more generally defined as the ability of the total system to maintain the aircraft position within a total system error (TSE) with a 95 percent probability and to stay within a specified aircraft containment surface which defines the obstacle clearance, terrain avoidance, or aircraft separation criteria for the intended operation. The total system error is based on the 95% probability combination of aircraft and non-aircraft sensor errors, display errors and flight technical errors at each point along the specified procedure. For approach, the outer tunnel must be used as the obstacle clearance surface. |
| 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 |
| Active Waypoint | A waypoint to or from which navigational guidance is being provided. For parallel offset, the active waypoint may or may not be at the same geographical position as the parent waypoint. When not in the parallel offset mode (operating on the parent route), the active and parent waypoints are at the same geographical position. |
| ACP ICAO | ICAO Aeronautical Communications Panel |
| 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. An aircraft resident processor that is specific to a particular air-ground data link (e.g. Mode S) which provides channel management, and segments and/or reassembles messages for transfer. It is connected on one side to aircraft elements common to all data link systems, and on the other side to the air/ground link itself. |
| ADME | Matters relating to airfield operations (ADME -> aerodrome) |
| ADNS | ARINC Data Network Service |
| ADPCM | Adaptive Differential Pulse Code Modulation |
| ADS | Automatic Dependent Surveillance |
| ADS-1 | ADS capability provided by the combination of FANS 1 |
| ADS-B | Automatic Dependent Surveillance Broadcast. ADS-B uses (Mode S) long squitter formats to broadcast aircraft position. The position is “heard” by a Ground Interrogator Receiver Unit (GIRU) on the ground and forwarded on to ATC. |
| ADS-B-ACC | ATC surveillance for en-route airspace |
| ADS-B-ADD | Aircraft derived data for ground tools |
| ADS-B-APT | Airport surface surveillance |
| ADS-B-NRA | ATC Surveillance in non-radar areas |
| ADS-B-TMA | ATC Surveillance in terminal areas |
| ADS-C | Automatic Dependence Surveillance Contract |
| ADSF | Automatic Dependent Surveillance Function |
| ADSP | ICAO Automatic Dependant Surveillance Panel |
| ADSU | Automatic Dependent Surveillance Unit or ADS Unit |
| ADT | IFATCA Airport Domain Team |
| Advisory | An annunciation that is generated when crew awareness is required and subsequent crew action may be required; the associated colour is unique but not red. |
| 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 |
| AFN | a) IFATCA Manual: Africa North b) Technical Manual: ATS Facilities Notification |
| AFP | Air Traffic Control Flight Plan Proposal |
| AFS | Aeronautical Fixed Service |
| AFTN | Aeronautical Fixed Telecommunication Network |
| AFW | Africa West |
| AGAS | Action Group for ATM Safety |
| AGL | Above Ground Level |
| AIDC | ATC Interfacility Data Communications |
| AIDS | Acquired Immune Deficiency Syndrome |
| AIP | Aeronautical Information Publication |
| Aircraft Address | A unique combination of 24-bits available for assignment to an aircraft for the purpose of air-ground communications, navigation, and surveillance. |
| AIRMET | Airmen’s Meteorological Information |
| AIS | Aeronautical Information Service(s) |
| AKN | Acknowledgement |
| AL | Alerting Service |
| Alert | An alert is an annunciation of an operating parameter of a navigation system being out of tolerance. Alerts include warnings, cautions, advisories, and integrity alarms. |
| Altimetry-Aiding | The process of using altitude data to simulate a GNSS satellite directly over the receiver antenna (i.e., it reduces, by one, the number of satellites required for a given function). Barometric altimetry (calibrated pressure) is most likely to be used in civil aircraft because few, if any, have high range radio (radar) altimeters installed. |
| AMA | Americas |
| AMC | Airspace Management Cell |
| AMCP | ICAO Aeronautical Mobile Communications Panel |
| AMJ | Advisory Material-Joint |
| AMS | Apron Management Services, |
| AMSS | Aeronautical Mobile Satellite Service |
| AMSSP | ICAO Aeronautical Mobile-Satellite Service Panel |
| 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 |
| AP | ICAO Aerodrome Panel |
| 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. A variable waypoint used, if needed, to link an LNAV/VNAV flight plan path with an ILS or DGNSS Instrument Approach’s Final Approach Segment. (Typically used to provide such linkage inside the Final Approach Fix, e.g., on a 3-mile final from the Runway Intercept Waypoint). |
| APL | Abbreviated Flight Plan |
| APM | Associate Professional Membership |
| APP | Approach Control |
| Applications | Specific use of systems that address particular user requirements. For the case of GNSS, applications are defined in terms of specific operational scenarios such as the support of en-route navigation or low- visibility aircraft taxiing. |
| APRs | Automatic Position Reports |
| APT | Airport Throughput (an EEC Research Area) |
| APW | Area Proximity Warning |
| ARCW | ADS Route Conformance Warning |
| ARINC | Aeronautical Radio Incorporation |
| ARINC-429 | Digital Interface |
| ARINC-429W | Williamsburg Protocol (ATN Committee) |
| ARINC-578-4 | Airborne ILS-Receiver |
| ARINC-618 | Air-Ground Character Oriented Protocol Specification |
| ARINC-619 | ACARS Protocols for Avionic End Systems |
| ARINC-620 | ACARS Applications |
| ARINC-622 | ACARS ATS Applications (ACARS/ATN Gateway) (AEEC Specification 622 – standardised bit-oriented applications) |
| ARINC-629 | Digital Interface (New) |
| ARINC-631 | VHF Aviation Packet Communications |
| ARINC-635 | HF Data Link Protocols |
| ARINC-636 | Onboard Local Area Network (OLAN) |
| ARINC-637 | Internetworking Specification |
| ARINC-638 | ATN Upper Layer Specification |
| ARINC-702 | FMCS, includes FMC/ACARS Data Link |
| ARINC-718 | Mode S |
| ARINC-724B-3 | Aircraft Communications Addressing and Reporting System (ACARS) |
| ARINC-741 | Aviation Satellite Communication System |
| ARINC-744 | Full-Format Printer |
| ARINC-745 | Automatic Dependent Surveillance (ADS) |
| ARINC-746 | Cabin Communications System |
| ARINC-748 | Communications Management Unit |
| ARINC-750 | VHF Data Radio |
| ARINC-751 | Gate-Aircraft Terminal Environment Link (Gatelink) – aircraft side |
| ARINC-752 | Airborne Radio Subsystem |
| ARINC-753 | HF Data Link System |
| 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 |
| ASI | Asia |
| 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 (see there) |
| ASP | 1) ICAO Airspace and Surveillance Panel 2) Asia and Pacific |
| ASPA-S&M | Enhanced sequencing and merging operations |
| ASPP | ICAO Aeronautical Fixed Service (AFS) Systems Planning for Data Interchange Panel |
| ASTERIX | All Purpose STructured Eurocontrol suRveillance Information EXchange |
| ATA | Air Transport Association |
| ATAR | Automatic Air Reporting |
| ATC | Air Traffic Control, Air Traffic Control Domain |
| ATC Control Authority | Person responsible for separation of aircraft (controller). |
| ATC Data Authority | ATC ground system peer used by the ATC Control Authority. |
| ATC Ground System Peer | Peer end-system with ATCComm for a given connection. |
| ATCC | Air Traffic Control Centre |
| ATCComm | Air Traffic Control Communications Systems (Hardware & Software) |
| ATCEUC | |
| ATCO | Air Traffic Control Officer |
| ATCS | Air Traffic Control Services |
| ATD | Along-Track Distance. The distance along the desired track from the waypoint to the perpendicular line from the desired track to the aircraft. |
| 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 |
| ATMCP | Air Traffic Management Operational Concepts Panel (ICAO) now ATMRPP |
| ATMRPP | ICAO Air Traffic Management Requirements and Performance Panel |
| ATN | Aeronautical Telecommunications Network |
| ATNP | ICAO ATN Panel (proposed 3/94) |
| ATO | Actual Time Over |
| ATRK | Along-Track Error. A fix error along the flight track resulting from the total error contributions. |
| 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 |
| ATSA-VSA | Enhanced traffic situational awareness during visual separation |
| ATSAW | Airborne Traffic Situation Awareness |
| ATO | Actual Time Over |
| ATRK | Along-Track Error. A fix error along the flight track resulting from the total error contributions. |
| 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 | Air Traffic Services Planning Manual |
| ATSU | Air Traffic Service Unit |
| AUP | Airspace Use Plan |
| AUSEP | Australian RNAV Standard |
| Availability | a) The availability of a navigation system is the ability of the system to provide the required guidance at the initiation of the intended operation. b) Availability risk is the probability that the required guidance will not be present at the initiation of the intended operation. c) Availability is an indication of the ability of the system to provide useable service within the specified coverage area. d) Signal availability is the percentage of time that navigational signals transmitted from external sources are available for use. e) Availability is a function of both the physical characteristics of the environment and the technical capabilities of the transmitter facilities. |
| AVPAC | Aviation VHF Packet Communications |
| AWOG ICAO | All Weather Operations Group |
| AWOP | ICAO All Weather Operations Panel |
Acronym |
Definition |
| Barometric Altitude |
Geopotential altitude in the earth’s atmosphere above mean standard sea level pressure datum surface, measured by a pressure (barometric) altimeter. |
| BDS | Comm-B Data Store |
| BER | Basic Encoding Rules. |
| BRL | Bearing Range Line |
| B-RNAV | Basic Area Navigation |
| Broadcast | The protocol within the Mode S system that permits uplink messages to be sent to all aircraft in cover, and downlink messages to be made available to all interrogators that have aircraft wishing to send the message under surveillance. |
Acronym |
Definition |
| 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 |
| CASCADE | Co-Operative ATS through Surveillance & Communication Applications Deployed in ECAC |
| CAT | Data Category |
| CATMAC | Co-operative Air Traffic Management Concept |
| Caution | An annunciation that is generated when immediate crew aware subsequent crew action will be required; the associated colour is amber/yellow. |
| CBA | a) Cost/Benefit Analysis b) Cross-Border Area |
| C-Band | Approx. 5,000MHz |
| 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 |
| Centre of Navigation | The mathematical point, referenced to the associated with the DGNSS navigation solution. This point would typically of the GNSS antenna, but could also be an offset or translated point (e.g., might be translated vertically to the level of the wheels of a large aircraft). |
| CEO | Chief Executive Officer |
| CFCG | ICAO Communication Failure Coordinating Group |
| CFMU | Central Flow Management Unit |
| CHI | Computer Human Interface |
| CIB | Controller Intervention Buffer |
| CIC | Controller Intervention Capability |
| CIC | 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 |
| CoE | Centre of Expertise |
| COF | Continuity [of a system]
a) The continuity of a system is the ability of the total system (compromising all elements necessary to maintain aircraft position within the defined airspace) to perform its function without non- scheduled interruptions during the intended operation b) The continuity risk is the probability that the system will be unintentionally interrupted and not provides guidance information for the intended operation. c) More specifically, continuity is the probability that the system will be available for the duration of a phase of operation, presuming that the system was available at the beginning of that phase of operation. |
| COM | Communications |
| COM/MET/OPS | Communications/Meteorology/Operations |
| Comm-A | A 112-bit interrogation containing the 56-bit MA message field. This field is used by the uplink SLM and broadcast protocols. |
| Comm-B | A 112-bit reply containing the 56-bit MB message field. This field is used by the downlink SLM, ground-initiated, and broadcast protocols. |
| Comm-C | A 112-bit interrogation containing the 80-bit MC message field. This field is used by the extended length message (ELM) uplink protocol. |
| Comm-D | A 112-bit reply containing the 80-bit MD message field. This field is used by the extended length message (ELM) downlink protocol. |
| COM-T | Communications Team |
| Connection | Transport Layer Relationship between peer end-systems. |
| Connection Management | Term used to describe the management of ATCComm connections. |
| Context Management |
An independent service that meets ATSC addressing requirements. It provides the mechanism for aircraft and ATC ground system peers to indicate availability to other ATN users and to convey the addresses to be employed. ATCComm interfaces with aircraft CM equipment to provide ATC ground system peers the addresses needed to establish communication with ATCComm. |
|
CONTRAN |
Brand name for a device to prevent aircraft from blocking each other during transmissions |
| CONUS | Contiguous United States |
| Coordinate Conversion | The act of changing the coordinate values from one system to another, e.g., from geodetic coordinates (latitude and longitude) to Universal Transverse Mercator grid coordinates. |
| COTS | Commercial Off-The-Shelf |
| Coverage | The coverage provided by a radio navigation system is that surface area or space volume in which the signals are adequate to permit the user to determine position to a specified level of accuracy. Coverage is influenced by system geometry, signal power levels, receiver sensitivity, atmospheric noise conditions and other factors which affect signal availability. |
| 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 |
| Crisis | State of inability to provide air navigation service at required level, affecting system and/or personnel, following an unusual or unforeseen situation. |
| 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. The difference between the desired course setting and the course that is actually set. |
| CTA | a) Control Area b) Calculated Time of Arrival |
| CTMO | Centralised Traffic Management Organisation |
| CTs | Controller Tools |
| CW | Carrier Wave |
| CWI | Continuous Wave Interference. |
Acronym |
Definition |
| D, R, P Areas | Danger, Restricted and Prohibited Areas |
| DA/H | Decision Altitude (Height). A specified altitude or height (A/H) in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established.
Note 1: Decision altitude (DA) is referenced to mean sea level and decision height (DH) is referenced to the threshold elevation. Note 2: The required visual reference means that section of the visual aids or of the approach area which should have been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change of position, in relation to the desired flight path. |
| 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) |
| Departure Clearance |
This service provides automated assistance for requesting |
| Designated RNAV Route |
An area navigation route based on the current high altitude or low altitude VOR/DME coverage, as designated by appropriate government agencies. |
| Desired Course: Magnetic | A predetermined desired course direction to be followed (measured in degrees from local magnetic north). |
| Desired Course: Station | A predetermined desired course direction to be followed (measured in degrees from station north). |
| Desired Course: True | A predetermined desired course direction to be followed (measured in degrees from true north). |
| DFDAU | Digital Flight Data Acquisition Unit |
| Dg | Degree |
| DGCA | Director-General Civil Aviation |
| DGNSS | Differential GNSS. Differential GNSS is an augmentation, the purpose of which is to determine position errors at one or more known locations and subsequently transmit derived information to other GNSS receivers in order to enhance the accuracy, integrity of the position estimate. |
| DGPS | Differential Global Positioning System |
| DIAS | Differential GNSS Instrument Approach System (see as well definitions: DIAS Integrity Alarm) |
| DIAS Integrity Alarm | A DIAS integrity alarm is a signal indicating an out-of-tolerance condition that might compromise the approach’s containment surface. |
| Direct Visual Observation | Observation through direct eyesight, not supported by means other than optical aids (glasses/lenses) that correct vision |
| DL | 1) Data Link 2) Downlink |
| DLAC | Data Link Applications Coding. |
| DLORT | FAA Data Link Operational Requirements Team |
| DMAP | ICAO Data Link Mobile Applications Panel (proposed) |
| DME | Distance Measuring Equipment |
| DO | Document |
| DOP | Dilution of Precision |
| DOTS | Dynamic Ocean Tracking System |
| Downlink | A term referring to the transmission of data from an aircraft to the ground. Mode S ground-to-air signals are transmitted on the 1,090 MHz reply frequency channel. |
| DPF | Data Processing Function. |
| DPSK | Differential Phase Shift Keying. |
| DR | Disconnect Request |
| DRMS | Distance Route Mean Square. The root-mean-square value of the distance from the true location point of the position fixes in a collection of measurements. The confidence level depends on the elongation of the error ellipse. As the error ellipse collapses to a line segment, the 2 DRMS confidence level approaches 95 percent (95.4%); as the error ellipse becomes circular, the confidence level approaches 98 percent (98.2%). In navigation system analysis, a 95% confidence level is assumed, thus all error budgets are conservative with respect to the actual obtainable accuracy. |
| DT | Data |
| DTF | Data Test Facility |
Acronym |
Definition |
| 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 | |
| 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. A segment collinear with the Final Approach Segment, starting at and extending beyond the Glide Path Intercept Waypoint, in the direction opposite from the landing runway. |
| 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. |
| En Route | A phase of navigation covering operations between departure and termination phases. En route phase of navigation has two subcategories: a) en route domestic / continental b) en route oceanic. |
| ENAV | Italian company for Air Navigation Services |
| ENRI | Electronic Navigation Research Institute |
| ER | Error |
| ERN | Earth Referenced Navigation. Navigation that is dependent on an external navigation source but is not dependent on a single fixed site. ERN may use either time or phase differences from hyperbolic radio navigation systems or satellite sources with earth models (datums) to determine position (normally latitude and longitude) on the surface of the earth. Omega, Loran- C, DME-DME and GNSS are different forms of ERN. |
| 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 AFI | 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 |
| EVP-A | Executive Vice President Administration |
| EVP-F | Executive Vice President Finance |
| EVP-P | Executive Vice President Professional |
| EVP-T | Executive Vice President Technical |
Acronym |
Definition |
| FAA | Federal Aviation Administration |
| FAB | Functional Airspace Blocks |
| FAF | Final Approach Fix. A point in space used to indicate the position at which an aircraft on a standard approach should be stabilised with appropriate guidance being supplied for the Final Approach Segment. (Source: FAA) |
| FANS | ICAO Future Air Navigation Systems |
| FANS/II | Special Committee for the Monitoring and Co-ordination of Development and Transition Planning for the Future Air Navigation Systems |
| FAR | Federal Aviation Regulation |
| FAS | Final Approach Segment. The straight line segment which prescribes the three-dimensional geometric path in space that an aircraft is supposed to fly on final approach. This segment is defined by two points in space, the Glide Path Intercept Waypoint (GPIWP) and the Threshold Crossing Waypoint (TCWP). |
| FAST | Future ATM Systems Team |
| FDI | Fault Detection and Isolation |
| FDP | Flight Data Processing. |
| FDPS | Flight Data Processing System |
| FDR | Flight Data Record |
| FEATS | ICAO Future European Air Traffic System |
| 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 |
| FLOS | Flight Level Allocation System |
| 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 |
| FMSG | Frequency Management Study Group. |
| FMU | Flow Management Unit |
| FOM | Figure of Merit. A system generated indication of the quality of the actual navigation performance of the aircraft. This is expressed as an indication of the aircraft position-fixing accuracy. [ICAO FANS Concept, ADSP]. Indicates aircraft position determination accuracy and navigation capability or whether accuracy is better than: FOM 0 : >30NM FOM 1 : <30NM FOM 2 : <15NM FOM 3 : <8NM FOM 4 : <4NM FOM 5 : <1NM FOM 6 : <0.24NM FOM 7 : <0.05NM |
| Four Eyes Principle | See: 4EP |
| FPA | Flight Path Angle. The angle that the vertical flight path of the aircraft makes with the local horizontal. |
| FPD | Flight Plan Data |
| FPL | Flight-Plan |
| FPLSG ICAO | Flight Plan Study Group |
| FPPS | Flight Plan Processing System |
| FRA | Free Route Airspace |
| FRAC | Free Route Airspace Concept |
| Frame | The basic unit of data transfer at link level. A frame can include from one to four Comm-A or Comm-B segments, or from two to sixteen Comm-C segments, or from one to sixteen Comm-D segments. |
| FRAP | Free Route Airspace Project |
| FRMS | Fatigue Risk Management Systems |
| FRN | Field Reference Number |
| FS | Functional Statement |
| FSPEC | Field Specification |
| FTE | Flight Technical Error. The accuracy with which the aircraft is controlled as measured by the indicated aircraft position with respect to the indicated command or desired position. It does not include blunder errors. |
| FTI | FUA Temporary Instruction |
| FTS | Fast-time Simulation |
| FUA | Flexible Use of Airspace |
| FX | Field Extension Indicator |
Acronym |
Definition |
| GA | General Aviation |
| GADS | Generic Aircraft Display Systems |
| GAIT | Ground-based Augmentation and Integrity Technique |
| GAT | General Air Traffic |
| GDLP | Ground Data Link Processor. A ground-resident processor that is specific to a particular air-ground data link (e.g. Mode S) which provides channel management, and segments and/or reassembles messages for transfer. It is connected on one side (by means of its DCE) to ground elements common to all data link systems, and on the other side to the air/ground link itself. |
| GDOP | Geometric Dilution of Position. The ratio of position error of a multilateration system. More precisely, it is the ratio of the standard deviation of the position error to the standard deviation of the measurement errors, assuming all measurement errors are statistically independent and have a zero mean and the same standard distribution. GDOP is the measure of the “goodness” of the geometry of the multilateration sources as seen by the observer; a low GDOP is desirable, a high GDOP undesirable. Applied to Loran-C, GDOP is a measure of horizontal accuracy, while with satellite navigation systems it is a measure of overall positional and temporal accuracy. (See also PDOP, HDOP and VDOP.) |
| GEO | Geostationary |
| Geocentric | Relative to the earth as a centre, measured from the centre of the earth. |
| Geodesy | The sciences related to the determination of the size and shape of the earth (geoid) by such direct measurements as triangulation, levelling and gravimetric observations; which determines the external gravitational field of the earth and, to a limited degree, the internal structure. |
| Geometric Altitude | Height above the local earth surface |
| Geostationary | An equatorial satellite orbit that results in a constant fixed position of the satellite over a particular earth surface reference point. (GPS and GLONASS satellites are not geostationary.) Some proposed integrity and augmentation schemes use geostationary satellites. |
| GES | Ground Earth Station |
| GIC | GNSS Integrity Channel (see there) |
| GICB | Ground-initiated Comm-B. The ground-initiated Comm-B protocol allows the interrogator to extract Comm-B replies from the transponder containing data from a defined source in the MB field. |
| GIRU | Ground Interrogator Receiver Unit. |
| GLONASS | Global Navigation Satellite System (Russian Federation) |
| GM | Guidance Material |
| GNSS | Global Navigation Satellite System(s) |
| GNSS Augmentation | GNSS augmentation is the technique of providing the system with input information, extra to that derived from the main constellation(s) in use, which provides additional range/pseudo-range inputs or corrections to, or enhancements of, existing pseudo-range inputs. This enables the system to provide a performance which is enhanced relative to that possible with the basic satellite information only. |
| GNSS Integrity Channel (GIC) | A system that broadcasts civil GNSS integrity information to users in a designated area, based upon measurements made by a ground-based monitor or network of monitors. |
| GNSS Planned Non availability | The proportion of time that the signals-in-space service of the GNSS is not useable taking into consideration scheduled outages only. |
| GNSS PSG Eurocontrol | GNSS Program Steering Group |
| GNSS Random Non availability |
The proportion of time and space over the area of interest when the services of the GNSS are not useable to support the required navigation performance.
Note 1: When referred to a selected point, rather than a defined area, GNSS random non availability is the portion of time that the services of the GNSS are not support the required navigation performance at this selected point. Note 2: GNSS random non-availability excludes planned non-availability. |
| GNSS Time | The overall time reference for and transmitted by the GNSS. GNSS time is precisely related to UTC but does not follow leap seconds. |
| GNSSP | ICAO Global Navigation Satellite Systems Panel now NSP |
| GOS | Grade of Service |
| GOSEP | Government Open Systems Interconnection Profile |
| GPIWP | Glide Path Intercept Waypoint. Generally located coincident with the point at which the glide slope intercept altitude meets the ILS glide slope. If no ILS glide slope exists; the point is co-located with the Final Approach Fix. |
| GPS | Global Positioning System. A space-based positioning, velocity and time system composed of space, control and user segments.
a) The space segment, when fully operational, will be composed of 21 satellites (plus three operational spares) in six orbital planes. |
| GPWS | Ground Proximity Warning System |
| GRAS | Ground-based Regional Augmentation System |
| GREPECAS | Caribbean/South American Planning and Implementation Regional Group |
| GS | Ground Speed. The speed of an aircraft measured by the distance the airplane travels over the ground, measured in nautical miles per hour (knots). |
| GWS | Graphic Weather Service. Provides an en route strategic weather service by way of scaleable graphics. |
Acronym |
Definition |
| 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. The ratio of user-referenced horizontal position error to measurement error of a multilateration system (See GDOP for a more detailed description.) |
| Height Above | Specifically, the height above the Runway Intercept Waypoint. |
| HELI | Helicopter Operations |
| HEO | Highly Elliptical Orbit |
| HF | High Frequency |
| HFS | Human Factors Specialist |
| HIV | Human Immune-deficiency Virus, other term for à AIDS |
| 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 |
| Hybrid | A navigation system relying on a combination of navigation sources. |
Acronym |
Definition |
| IA5 | International Alphabet #5 |
| IACSP | International Communications Service Provider |
| IAF | Initial Approach Fix |
| IAG | |
| 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 | |
| ICAO | International Civil Aviation Organisation |
| ICB | Industry Consultation Body (European Commission) |
| ICCAI | International Co-ordinating Council of Aerospace Industries Associations |
| 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 |
| IDSG | ICAO Internet Working Standards Drafting Group |
| IFALPA | International Federation of Airline Pilots’ Associations |
| IFATCA | International Federation of Air Traffic Controllers’ Associations |
| IFATSEA | |
| IFER | In-Flight Emergency Response |
| 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. A 3-dimensional, high-precision waypoint located in the near vicinity of the runway used to establish the Initial Missed Approach Segment. |
| IMC | Instrument Meteorological Conditions |
| IN | Information Need |
| Initial Missed Approach Segment | A segment extending from the Runway Intercept Waypoint to the Initial Missed Approach Waypoint. This segment is primarily used for lateral guidance during an initial missed approach until other missed approach criteria become effective. |
| INMARSAT | International Maritime Satellite Organisation |
| INO | Innovative Research (an EEC Research Area) |
| INS | a) Inertial Navigation System b) Insert |
| Instrument Approach Waypoints | Position fixes that may be used in defining RNAV approach procedures are the:
a) Initial Approach Waypoint (IAWP) |
| Integrity | a) The integrity of a system is that quality which relates to the trust which can be placed in the correctness of the information supplied by the total system.
b) Integrity risk is the probability of an undetected (latent) failure of the specified accuracy. c) Integrity includes the ability of the system to provide timely warnings to the user when the system should not be used for the intended operation. |
| Integrity Monitoring | GNSS integrity monitoring is a GNSS subsystem which enables the timely detection and indication of malfunctions in GNSS operations to ensure the user is aware of whether or not the system is operating within its specified performance limits. |
| IOACG | Informal Indian Ocean Air Traffic Services Coordinating Group |
| IOC | Initial Operational Capability. The equipment and facilities, operational procedures, and training, on the ground and in the aircraft, required to achieve the first benefits in routine flight operations (i.e., a few aircraft operating in selected environments). |
| 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 |
| ITU | International Telecommunication Union |
| ITWS | Integrated Terminal Weather Service |
| IWP | Interim Working Party |
Acronym |
Definition |
| JC | Just Culture |
| JCAB | Japan Civil Aviation Bureau |
| JPB | Joint Programme Board |
| KPI | Key Performance Indicator |
| kt | knot = NM/hour, unit of speed |
Acronym |
Definition |
| LADGNSS | Local Area Differential GNSS |
| LAN | Local Area Network |
| LAT/LONG | Latitude / Longitude |
| Lat/Long Reference |
A waypoint, defined using latitude/longitude, from which |
| L-Band | Approx 1,500MHz |
| LEN | Length Indicator |
| LEO | Low Earth Orbit |
| LOEU | Liaison Officer European Union |
| LO EURO | Liaison Officer EUROCONTROL |
| LOIG | Liaison Officer to International Organisations |
| LOSA | Line Operations Safety Audit |
| LPC | Linear Predictive Coding |
| LPO | Lone Person Operation: Operations where an ATCO is providing a service with no other person available on the unit, ATCO or otherwise. |
| LPRI | ICAO Language Proficiency Requirements |
| LRU | Line Replaceable Unit |
| LSB | Least Significant Bit |
| LVA | Large Vertical Aperture |
| LVO | Low Visibility Operations |
Acronym |
Definition |
| MA | Member Association |
| MADAP | Maastricht Automated Data Processing and Display System |
| MAEVA | Master ATM European Validation Plan |
| MALE | Medium Altitude Long Endurance |
| Manoeuvre Anticipation |
A means, achieved either by equipment mechanisation or procedurally, by which path changes are initiated in either 2D or 3D navigation. |
| MAP | Missed Approach Point |
| MAPT | Missed Approach Point |
| Mask Angle | A fixed elevation angle referenced to the user’s horizon below which satellites are ignored by the receiver software. Mask angles are used primarily in the analysis of GNSS performance, and are employed in some receiver designs. The mask angle is driven by the receiver antenna characteristics, the strength of the transmitted signal at low elevations, receiver sensitivity and acceptable low elevation errors. |
| MASPS | a) Minimum Aeronautical System Standards b) Minimum Aircraft System Performance Specification c) Minimum Aviation System Performance Specification d) Minimum Aviation System Performance Standards |
| Maximum Allowable Warning Rate | The maximum allowable warning rate of a system is the upper bound of total warning rate (all sources of warnings that the system can generate) with the system in normal operation. |
| MB | Message, Comm B |
| MBI | Message Block Identifier |
| MBS | Model Based Simulations |
| MCDU | Multifunction Control Display Unit |
| Message | Basic unit of information exchanged between ATCComm and the ATC ground system peer. |
| Message Element | A component of a message used to define the context of the information exchanged. |
| Message Header | Control information used to maintain synchronisation between ATCComm and the ATC ground system peer. |
| Message Identification Number | A unique number assigned to each message. This number is used to differentiate messages and is conveyed in the message header. |
| Message Reference Number | Used to uniquely associate a response with a previously received message. The Message Identification Number of a previously received message becomes the Message Reference Number of the |
| MET | Meteorological |
| MFF | Mediterranean Free Flight Programme |
| MID | Middle East |
| MIFR | Master International Frequency Registration |
| Minimum Useable Elevation Angle |
The minimum satellite elevation, above the user’s local horizon, that the satellite can be reliably used in the calculation of a navigation solution. The minimum useable elevation angle varies depending on the environment, the antenna design and placement, aircraft altitude and attitude. |
| MLS | Microwave Landing System |
| MLAT | Multilateration |
| MMI | Man-Machine Interface |
| MNC | Multi -National Corporations |
| MNPS | a) Minimum Navigation Performance Specification b) Minimum Navigation Performance Standards |
| MNT | Mach Number Technique |
| MOC | Mean Of Compliance |
| MODE S | Mode Select Transponder. Transponder that is capable of modes “A” & “C” (SSR & Data Link) |
| Mode S PSG | Mode S Program 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 |
| MSCP | Mobile Satellite Service Provider |
| MSE | Mean Square Error |
| MSK | Minimum Shift Keying |
| MSP | 1. Mode S Specific Protocol: A Mode S specific protocol that provides a restricted datagram service within the Mode S subnetwork. 2. Multi Sector Planning: Situation where two or more executive controllers working different sectors are assisted by another appropriately qualified controller. |
| 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 |
| Multisensor
Navigation |
Where aircraft position is determined using data derived from two or more independent sensors (e.g., Loran-C, VOR, Omega) each of which is useable (i.e., meets required navigation performance including accuracy, availability and integrity) for each of which is useable (i.e., meets required navigation performance including accuracy, availability and integrity) for airborne navigation. |
| MWARA | Major World Air Route Area |
Acronym |
Definition |
| NA | Not Applicable |
| NACK | Negative Acknowledgement |
| NAD | North American Datum |
| NADIN | National Airspace Data Interchange Network |
| Nanosecond | One billionth of a second |
| 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 | Radio Aid to Navigation |
| NAVD | North American Vertical Datum |
| Navigation | The means by which an aircraft is given guidance to travel from one known position to another known position. The process involves referencing the actual aircraft position to a desired course. |
| Navigation
Guidance |
The calculation of steering commands to maintain the desired track from the present aircraft position to a new position. |
| Navigation
Information |
The calculation and display of aircraft present position, velocity vector and related data, such as track angle, ground speed and drift angle. |
| 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) |
| Non-Precision
Approach |
A standard instrument approach procedure in which no glideslope / glidepath is provided. |
| 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 Services Panel |
| NUAC | Nordic Upper Air Centre |
| NUP II | North European Update Programme Phase II |
Acronym |
Definition |
| O.R. | Operational Requirement |
| OAS | Oceanic Automation System |
| OAT | Operational Air Traffic |
| OCA | Oceanic Control Area |
| OCM | Oceanic Clearance Message. This service provides automated assistance for requesting and delivering an oceanic clearance. |
| OCP | ICAO Obstacle Clearance Panel |
| 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 |
| ODL | Oceanic Data Link |
| OFC | Off-Centre |
| OJT | On-The-Job-Training |
| OLDI | On-line Data Interchange |
| Op | Operational |
| OP SUP | Operational Supervisor |
| OPD | Optimized Profile Descents |
| OPLINK | Operational Data-Link Panel |
| OPMT | Operations Planning Management Team |
| OPS | a) Operations
b) Operational Services (an EEC Centre of Expertise) |
| OPSP | ICAO Operations Panel |
| OPTUS | Name of one of Australia’s Telecommunications Providers |
| ORI | Orientation |
| OSED | Operational Services and Environment Description |
| OSI | a) Open System Interface
b) Open Systems Interconnection |
| OSST | FAA Oceanic Separation Standards Team |
| OTC | Overseas Telecommunications Company |
Acronym |
Definition |
| PAC | Pacific |
| Packet | The basic unit of data transfer among communications devices within the network layer, (e.g. an ISO-8208 packet or a Mode S packet). |
| PACOTS | Pacific Organized Track System |
| PANS-ATM | Procedures for Air Navigation Services Air Traffic Management Rules of the Air and Air Traffic Services (ICAO DOC 4444) |
| PANS/RAC | Procedures for Air Navigation Services – now called the PANS/ATM |
| PANS-OPS | Procedures for Air Navigation Services – Aircraft Operations |
| Parent Waypoint | A waypoint used for route definition and/or progress reporting. The geographical position of a parent waypoint is not altered when RNAV equipment is operated in a parallel offset mode. |
| 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. The ratio of user-referenced three-dimensional position error to measurement error of a multilateration system. PDOP is the root-sum-square of HDOP and VDOP |
| PEDI | Planning, Education, Demonstration, and Implementation |
| PER | Packed Encoding Rules |
| PET | Pacific Engineering Trials |
| PF | Position Fix Error |
| PFE | Path Following Error. That portion of the guidance signal error which could cause aircraft displacement from the desired course or glide path. These perturbations fall within the loop guidance bandwidth of an aircraft. The path following error is composed of the path following noise and the mean course error, in the case of azimuth functions, or the mean glide path error, in the case of elevation functions. The PFE is measured by filtering the output flight navigation error record with a second order low pass filter with a comer frequency of 0.5 radians per second lateral guidance and 1.5 radians per second for vertical guidance and a slope of 12 dB/octave for both cases. |
| PFL | Planned Flight Level |
| PHARE | Program for Harmonised ATM Research in EUROCONTROL |
| Phase of Operation | A phase of operation is a period of navigation with a constant required navigation performance. Note: Traditionally, the term “phase of flight” has related to periods of navigation with different procedures/criteria such as en route (continental, oceanic), terminal, approach, and landing. As the RNP concept is introduced, “phase of operation” will relate more to a particular RNP. For example, in the future, the continental en route phase of flight may be divided into more than one phase of operation, since several RNPs may be included as an aircraft transits a continental area. |
| PI | Performance Indicators |
| PIAC | Peak Instantaneous Aircraft Count |
| PM | Policy Material |
| POLSTATS | Policy Statements |
| Position Determination Error | The accuracy with which a navigation sensor can calculate and provide an output of actual location in an operational environment. |
| Position Fix | A derived location of an entity in a common coordinate system. |
| Position Fixing Error | The accuracy with which a navigation sensor in combination with a navigation computer can calculate and provide an output of actual location in relation to desired location in an operational environment. |
| 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 |
| Precision Approach | A standard instrument approach procedure in which a glideslope / glidepath is provided. |
| Predictable Accuracy | The accuracy of a position with respect to the geographic or geodetic coordinates of the Earth. |
| PRN | Pseudorandom Number |
| Propagation Delay | The time delay of a signal created as the signal travels between antennas through a propagation medium. |
| PRU | Performance Review Units (Eurocontrol) |
| Pseudolite | A pseudolite (pseudo-satellite) is a ground-based GNSS augmentation which provides, at GNSS satellite signal-in-space frequencies, an additional navigation ranging signal. The augmentation may include additionally differential GNSS corrections. (Adapted from the FANS GNSS Technical Subgroup). |
| Pseudo-range
(PR, PRC) |
The distance from the user to a satellite plus an unknown user clock offset distance. With four satellite signals it is possible to compute position and offset distance. If the user clock offset is known, three satellite signals would suffice to compute a position. |
| PSR | Primary Surveillance Radar |
| PSTN | Public Switched Telecommunications Network |
| PWP | Pilot Working Position |
Acronym |
Definition |
| 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 |
Acronym |
Definition |
| R&D | Research and Development |
| R/T | a) Radio Transmission
b) Radio Telephony |
| RA | Resolution Advisory |
| RACE | Runway Safety |
| RAD | Material relating to the provision of radar services |
| Radionavigation | The determination of position, or the obtaining of information relating to position, for the purposes of navigation by means of the propagation properties of radio waves. |
| RAIM | Receiver Autonomous Integrity Monitoring. A technique whereby a civil GNSS receiver/processor determines the integrity of the GNSS navigation signals without reference to sensors or non-DoD integrity systems other than the receiver itself. This determination is achieved by a consistency check among redundant pseudo-range measurements. |
| 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 | Recategorisation (of aircraft for wake turbulence) |
| Reference
VOR/DME Facility |
The VOR/DME (VORTAC) (TACAN) facility with its designated latitude / longitude position used for the identification and establishment of an RNAV route or flight procedure. |
| Relative
Accuracy |
The accuracy with which a user can determine one position relative to another position, regardless of any error in their true positions. |
| Reliability | The probability of performing a specified function without failure under given conditions for a specified period of time. |
| REM | Rapid Eye Movement |
| REP | Field Repetition Indicator |
| Repeatable
Accuracy |
The accuracy with which a user can return to a position whose coordinates has been measured at a previous time with the same navigation system. |
| RF | Radial to Fix (method of turn) |
| RFG | Requirements Focus Group |
| RFI | Radio Frequency Interference |
| RFP | Request for Proposal |
| RGCSP | ICAO Review of the General Concept of Separation Panel |
| RGS | Remote Ground Station |
| RHCP | Right-Hand-Circular Polarised |
| RLASM | Reduced Lateral Separation Minima |
| RLOSM | Reduced Longitudinal Separation Minima |
| RMM | Remote Maintenance Monitoring |
| RNAV | Area Navigation. Application of the navigation process providing the capability to establish and maintain a flight path on any arbitrary chosen course that remains within the coverage area of navigation sources being used. RNAV utilising capabilities in the horizontal plane only is called 2D RNAV, while RNAV which also incorporates vertical guidance is called 3D RNAV. Time navigation (TNAV) may be added to either 2D or 3D systems. TNAV added to a 3D system is called 4D. |
| RNAV Approach (2D) | An RNAV approach procedure utilising the lateral (2D) guidance capability of the 2D RNAV equipment to perform an approach manoeuvre. |
| RNAV Approach
(3D) |
An RNAV approach procedure utilising both the lateral (2D) and vertical VNAV guidance capability of the 3D RNAV equipment to perform an approach manoeuvre. |
| RNAV Approach
(4D) |
An RNAV approach procedure utilising the lateral (2D), vertical VNAV, and time guidance capability of GNSS RNAV equipment to perform an approach manoeuvre. |
| RNAV Route | Area Navigation Route. An en-route segment, arrival or departure route (including RNAV SIDs and STARs). It may also include en-route segments established with gaps in station coverage for use by RNAV-equipped aircraft capable of automatic dead reckoning.
a. The en route phase is normally construed as operations either on RNAV routes designated as high-low altitude routes, or direct point-to-point operations between designated waypoints. b. The terminal phase is considered as the transition from the departure runway to the first en route waypoint or the transition from the en route phase of the last en route waypoint until the initial approach fix/waypoint. A nominal value for the extent of the terminal phase would be that airspace extending approximately 50 miles from the departure or arrival airport. c. The approach phase is that portion of the flight starting at the initial approach fix/waypoint and terminating at the missed approach point. Normally, the final approach fix/waypoint is located within 10 miles from the runway threshold. The missed approach area is included in the approach phase in order to define accuracy requirements. |
| RNDSG | Route Network Development Sub Group |
| RNP | Radio Navigation Performance. IFATCA Manual: A parameter describing lateral deviations from assigned or selected track as well as along track position fixing accuracy on the basis of an appropriate containment level (1, 4, 12.6, or 20NM) |
| RNP | Required Navigation Performance. Technical Manual: A parameter describing lateral deviations from assigned or selected track as well as along track position fixing accuracy on the basis of an appropriate containment level (1, 4, 12.6, or 20NM) |
| RNP GM | Guidance Material for Required Navigation Performance |
| Route Segment | Two subsequently related waypoints (or ATD fixes) define an RNAV route segment. |
| ROT | Remotely Operated Tower(s) |
| RPA | Remotely Piloted Aircraft |
| RPL | Repetitive Flight-Plan |
| RPV | Remotely Piloted Vehicle |
| RRC | Range Rate Correction |
| RSP | Required System Performance. Required System Performance, consists of RNP, required communication performance, and required monitoring performance. |
| RSS | Root-sum-square |
| RSSP | Radar Systems Specialist Panel |
| RTA | Required Time of Arrival |
| RTCA | RTCA Inc., Task Force 1 – GNSS Transition and Implementation Strategy. Task Force 2 – Transition to Digital Communications (formerly Requirements and Technical Concepts for Aviation formerly Radio Technical Commission for Aeronautics) |
| RTCM | Radio Technical Commission for Maritime |
| RTF | Radiotelephony |
| RTS | Real-time Simulation |
| Runway Segment | The segment between the Runway Intercept Waypoint and the Runway End Waypoint. |
| RVSM | Reduced Vertical Separation Minima |
| RWEWP | Runway End Waypoint. A 3-dimensional, high-precision waypoint at the landing rollout end of the runway. The RWEWP, if needed, will be used to define rollout courses, runway remaining, etc. |
| RWIWP | Runway Intercept Waypoint. A 3-dimensional, high precision waypoint located at the present GPIP, or at a standard “down runway” distance (e.g., 1000 foot point). |
| RWY | Runway |
| RWSL | Runway Status Lights |
Acronym |
Definition |
| s | second, unit of time |
| SA | a) Selective Availability. A set of techniques for denying the full accuracy and selecting the level of positioning, velocity, and time accuracy of GPS available to users of the Standard Positioning Service (L1 frequency) signal
b) Situational Awareness |
| SAC | System Area Code |
| SAE | Society of Automotive Engineers |
| SAGE | The Safety Awareness Group at the EEC |
| SAM | a) Safety Assessment Methodology
b) South America |
| SAP | ICAO Aeronautical Fixed Service (AFS) Systems Panning for Data Interchange Panel |
| 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) |
| Satellite Health | The ability of the satellite’s navigation signal for unaugmented (stand alone) GNSS navigation. |
| SBC | Sub-Band Coding |
| SBU | Separate Business Units |
| SC | a) Special Committee
b) Standing Committee |
| SC-142 | RTCA Special Committee 142 Mode S |
| SC-159 | RTCA Special Committee 159 Global Positioning System (GPS) |
| SC-162 | RTCA Special Committee 162 Open Systems Interconnect (OSI) |
| SC-165 | RTCA Special Committee 165 Aeronautical Mobile Satellite Service (AMSS) |
| SC-167 | RTCA Special Committee 167 Software |
| SC-169 | RTCA Special Committee 169 Data Link Communications |
| SC-170 | RTCA Special Committee 170 ADS |
| SC-172 | RTCA Special Committee 172 VHF Air-Ground Communication |
| SC-186 | Special Committee 186 (for ADS-B) |
| SCAT-1 Approach | Special Category 1 Approach. A specially authorised DGNSS Instrument Approach using a DGNSS Instrument Approach System satisfying a specific RNP that allows operations to MLS/ILS Category 1 minima, with differential GNSS used to provide navigation guidance. |
| SCIA | Simultaneous Converging Instrument Approaches |
| SCRSP | Surveillance and Conflict Resolution Systems Panel |
| SDM | Sum Depth of Modulation (ILS ) |
| SDPS | Surveillance Data Processing System |
| Secondary Sensor | Any input from other aircraft systems that may be used to derive navigation information. |
| SEE | Society, Environment, Economics (an EEC Research Area) |
| SEG | |
| Segment | A portion of a message that can be accommodated within a single MA/MB field in the case of an SLM or a single MC/MD field in the case of an ELM. |
| SELCAL | Selective Call |
| SEP | Policy on Separation Standards |
| Service Coverage | The coverage provided by a radio navigation system in that area or space volume in which the signals are adequate to permit the navigator to determine position to a specific level of accuracy. Coverage is influenced by system geometry, signal power levels, receiver sensitivity, atmospheric noise conditions and other factors which affect signal availability. |
| 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 |
| SICASP | ICAO Secondary Surveillance Radar Improvements and Collision
Avoidance Panel |
| SID | Standard Instrument Departure |
| SIGMET | Significant Meteorological Information |
| Signal-Derived
Position Error |
That part of the horizontal position error at the user location attributable to signal-in-space errors from the GNSS control segment, space segment and propagation effects; does not include receiver-induced errors. |
| Signal-Derived
Range Accuracy |
Measured pseudorange error on a particular satellite as observed by a ground monitor station. SRA includes the sign of the error. |
| SIMOPS | Simulation Operations |
| SIRO | Simultaneous Intersecting Runway Operations |
| SITA | Societe International de Telecommunications Aeronautiques |
| SITF | Study and Implementation Task Force |
| Situational
Awareness |
An integrated understanding of factors that contribute to the operation of aircraft / vehicles under normal and abnormal conditions. Factors affecting situational awareness include spatial awareness, awareness of environment, vehicle performance awareness, aircraft/vehicle systems awareness, and operator / crew / controller awareness. |
| Slant Range | The actual straight line distance between an aircraft in flight and a ground location (radar, DME). This distance is greater than the geographical surface range because of the altitude. |
| SLM | Standard Length Message. An exchange of digital data using selectively addressed Comm-A interrogations and/or Comm-B replies. |
| SLOP | Standard Lateral Offset Procedures |
| SM | Scale Marker |
| SMC | System Management and Communication |
| SMF | Separation Monitoring Function |
| SMGCS | Surface Movement Guidance and Control System |
| SMR | Surface Movement Radar |
| SMS | a) Safety Management System
b) Surface Movement System |
| SOIT | FAA Satellite Operations Implementation Team |
| Sole Means of
Navigation |
A means of navigating the aircraft where position determination is provided by a system which satisfies the required navigation performance (RNP) for a particular phase of operation. |
| SP | Special Purpose Indicator |
| SPF | Strategic Performance Framework |
| SPI | Special Position Identification |
| SPO | Single Person Operations |
| SPR | Safety and Performance Requirement |
| SPS | Standard Positioning Service. The standard specified level of positioning, velocity and timing accuracy that is available, without qualifications or restrictions, to any user on a continuous world-wide basis. |
| SPT | Strip Printer |
| SRA | Strategic Research Agenda |
| SRC Eurocontrol | Safety Regulation Commission |
| SRDP | Safety Research and Development Plan |
| SRE | Slant Range Error. Slant range error is the difference between the distance of an aircraft (Point A) to a DME station on the surface (Point B) and the distance from the station (Point B) to a point directly beneath the aircraft on the surface (Point C). The error magnitude is a function of aircraft altitude above the station and the distance to the station. |
| SSC | |
| SSG | Safety Group |
| SSP | Sector Safety and Productivity (an EEC Research Area) |
| SSR | Secondary Surveillance Radar |
| SSRP | Strategic Safety Research Plan |
| SSWG | System Support Working Group |
| Stand-Alone
GNSS System |
An airborne GNSS configuration which may use altimeter aiding and augmented GNSS signals without reliance on any other navigation system or sensor. |
| STAR | a) Standard Instrument Arrival (Route) b) Standard Arrival Route |
| Station North | The assigned north reference for a particular station. |
| Station-Referenced
Navigation |
Position determination that is referenced to a stationary fix. |
| STC | Supplementary Type Certification |
| STCA | Short Term Conflict Alert |
| STFRDE | Surveillance Task Force for Radar Data Exchange (previous RDE-FG) |
| Subnetwork | An actual implementation of a data network which employs a homogeneous protocol and addressing plan, and is under the control of a single authority. |
| Supplemental Air Navigation System | An approved navigation system that can be used in controlled airspace of the National Airspace System in conjunction with a sole means navigation system. |
| SUR-T | Surveillance Team (EATM) |
| SVC | System View Cell |
| S-VFR | Special-VFR |
| SWIM | System-Wide Information Management |
Acronym |
Definition |
| TA mode | Traffic Advisory mode |
| TACAN | Tactical Air Navigation |
| TAS | True Airspeed. The actual speed of an aircraft relative to the air through which it is flying corrected for temperature and air density. |
| 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. The height of the straight line extension of the glide path above the runway at the threshold. |
| TCP | Transport Control Protocol |
| TCP/IP | Transmission Control Protocol/Internetwork Protocol. |
| TA mode | Traffic Advisory mode |
| TACAN | Tactical Air Navigation |
| TAG | Tactical Action Group |
| TAS | True Airspeed. The actual speed of an aircraft relative to the air through which it is flying corrected for temperature and air density. |
| 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. The height of the straight line extension of the glide path above the runway at the threshold. |
| TCP | Transport Control Protocol |
| TCP/IP | Transmission Control Protocol/Internetwork Protocol. |
| TCWP | Threshold Crossing Waypoint. A three-dimensional, high-precision waypoint typically located 50 to 55 feet above the runway threshold. This height may vary depending upon the specific airport configuration. |
| TDLS | Tower Data Link System |
| TDM | Track Definition Message |
| TDWR | Terminal Doppler Weather Radar |
| Technology Independent | Each new technology doesn’t require its own standard |
| TEM | Threat and Error Management |
| Terminal Area | A general term used to describe airspace in which approach control service or airport traffic control service is provided. |
| TERPS | Terminal Instrument Procedures |
| TIBA | Traffic Information Broadcast (by aircraft) |
| Time to Alert | Time to alert is the maximum allowable time interval between system performance going outside of operational performance limits and the appropriate integrity monitoring subsystem providing an alert. |
| TIS | Traffic Information Service: provides a cockpit display of traffic information of all targets within 7NM of the aircraft requesting the information. TIS processes Mode S surveillance data from the ground and display the data on a TCAS I-like display. |
| 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. A function of RNAV equipment that provides the capability to arrive/depart at a waypoint at a specified time. When added to a 3D system, TNAV is called 4D. |
| TOBT | Target Off Block Time |
| TO-FROM Equipment | RNAV equipment in which the desired path over the ground is defined as a specific (input quantity) course emanating either to or from a particular waypoint. In this equipment, the aircraft may fly either TO or FROM any single designated waypoint. |
| TO-TO Equipment | RNAV equipment in which a path is computed that connects two waypoints. In this equipment, two waypoints must always be available, and the aircraft is usually flying between the two waypoints and TO the active waypoint. |
| Touchdown | In using this term for airborne equipment specifications, care |
| TP | Turn Point. A waypoint which identifies a track change from one desired track to another along a given route. |
| TP4 | Transport Protocol Class 4 |
| TPC | Technical Policy Coordinator |
| TPDU | Transport Protocol Data Unit |
| TP Manual | IFATCA Technical and Professional Manual |
| TPS | IFATCA Technical and Professional Secretary |
| TQM | Total Quality Management |
| TRA | Temporary Reserved Area |
| TRKIANG | Track Angle |
| TRM | Team Resource Management |
| TRS | Transmission message |
| TSA | Temporary Segregated Area |
| TSAP-ID | Transport Service Access Point Identifier |
| TSE | Total System Error Generic: The root-sum-square of the navigation source error, airborne component error, display error, and flight technical error. Specific: The root-sum-square of the position fixing error, display error, course selection error, and flight technical error. |
| TSO | Technical Standard Order |
| TWDL | Two-Way Data Link Communication |
| TWIP | Terminal Weather Information for Pilots: provides a cockpit display to pilots of convective weather information in specific terminal areas. |
| Two Eyes Principle | See: 2EP |
| TWP | Technical Work Program of the Organisation in the Air Navigation Field |
| TWPC | Two-Way Pilot Controller |
| TWR | Aerodrome Control Tower |
Acronym |
Definition |
| U.S. | United States of America |
| UA | Unmanned Aircraft |
| UAC | Upper Area Control Centre |
| UAP | a) Upper Airspace Project b) User Application Profile |
| UAS | Unmanned Aircraft Systems |
| UASSG | ICAO Unmanned Aerial Systems Study Group |
| UAT | Universal Access Transmitter |
| UAV | Uniform Annual Values |
| 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 Program |
| Uplink | A term referring to the transmission of data from the ground to an aircraft. Mode S ground-to-air signals are transmitted on the 1,030 MHz interrogation frequency channel. |
| URA | User Range Accuracy. The one-sigma estimate of user range errors in the navigation data for each individual satellite. It includes all errors for which the space or control segment is responsible. It does not include any errors introduced at the user set. |
| UTC | Co-ordinated Universal Time |
| UUP | Updated Airspace Use Plan |
Acronym |
Definition |
| VDEV | Vertical Deviation. The deviation of the aircraft above or below the vertical profile as displayed on an indicator such that deflection is up when the aircraft is below the vertical profile. |
| VDL | VHF Data Link |
| VDOP | Vertical Dilution of Precision. The ratio of user-referenced vertical position error to measurement error of a multilateration system (see GDOP for a more detailed description). |
| 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. A function of RNAV equipment which calculates displays and provides guidance to a vertical profile or path. |
| VOR | VHF Omnidirectional Radio Range |
| VP | Vertical Profile. A line or curve, or series of connected lines and/or curves in the vertical plane, defining an ascending or descending flight path either emanating from or terminating at a specified waypoint and altitude, or connecting two or more specified waypoints and altitudes. In this sense, a curve may be defined by performance of the airplane relative to the air mass. |
| VP-A | Vice President Administration |
| VPAE | Vertical Profile Angle Error. The difference in degrees that the current aircraft flight path angle makes with the vertical profile. |
| VPF | Vertical Position Fix Error |
| VPIP | Vertical Profile Intercept Point. The point at which the current aircraft flight path angle intercepts the vertical profile. |
| VP-P | Vice President Professional |
| VP-T | Vice President Technical |
| VSM | Vertical Separation Minimum |
| VSWR | Voltage Standing Wave Ratio |
Acronym |
Definition |
| W/E | Warning/Error Condition |
| W/P | Waypoint |
| WA | Wind Angle. The direction from which the wind is blowing measured in degrees from true or magnetic north. |
| WADGNSS | Wide Area Differential GNSS |
| WAN | Wide Area Network |
| Warning | An annunciation that is generated when immediate recognition and corrective or compensatory action is required; the associated colour is red. |
| Waypoint – (W/P) | A predetermined geographical position used to define routes and / or progress reporting fixes that is defined by latitude and longitude and/or relative to a VORTAC or VOR/DME reference facility by magnetic radial bearing and range in nautical miles. |
| Waypoint Displacement Area | The rectangular area formed around the plotted position of the waypoint. The rectangle is oriented along the desired track with the waypoint at its centre. Its dimensions are two times the appropriate plus-or-minus along- track and cross-track displacement error values. |
| WCM | World Class Manufacturers |
| WG | Working Group |
| WGS | World Geodetic Survey |
| WGS-84 | World Geodetic System 84 |
| WHO | World Health Organisation |
| WADGNSS | Wide area differential GNSS |
| WIP | Working Group for Runway Incursion Prevention |
| WP | Working Paper |
| WS | Wind Speed. The speed with which the wind is blowing measured in knots. |
Acronym |
Definition |
| XTK | Cross-Track Distance. The perpendicular distance that the airplane is to the left or right of the desired track. |
Last Update: November 3, 2019
November 3, 2019 261 Jean-Francois Lepage TPM