Acronyms and Terms

Acronyms and Terms

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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.
b) The control segment consists of five monitor stations, three ground antennas and a master control station.
c) The user segment consists of antennas and receiver-processors that provide positioning, velocity, and precise timing to the user.

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)
b) Intermediate Waypoint (INWP)
c) Final Approach Waypoint (FAWP)
d) Missed Approach Waypoint (MAWP)
e) Runway Waypoint (RWY WP)
f) Holding Waypoint.

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  

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