PEC电子英语证书考试-航空电子词汇

PEC电子英语证书考试-航空电子词汇.xxV(ss)The impending low speed stall speed, xx istypically a number between 0.06 and 0.10. 1.06of stick shaker speed would be an example.,3V(ss)Target approach speed indicator. 1.3 of stickshaker speed.3-D, 4-DThree or four dimension4096 CodeThe octal base, four-digit code used betweenframing pulses of a reply to identify the aircraft orfor general use and emergency codes (XPD)0 Base T10 Mbps base band data transmission overtwisted copper wireA(1 ) Auto tuned NAVAID(2 ) Amperes(3 ) Aileron(4 ) At or Above (Altitude Suffix)A-SMGCSAdvanced Surface Movement Guidance andControl SystemA66ARINC 661AACAeronautical Administrative CommunicationsAADAssigned Altitude DeviationA AIAirline Avionics InstituteAALAbove Aerodome LevelAAMPAdvanced Architecture Micro-ProcessorA ATSAviation and Air Traffic ServicesA ATTAdvanced Aviation Transportation TechnologyA/BAutobrakeABEARINC 429 Bus EmulatorABMAsynchronous Balanced ModeA-BPSK(1 ) Aeronautical Binary Phase Shift Keying(2 ) Aviation Binary Phase Shift KeyingABRVAbbreviationABSAbsoluteAC(1 ) Advisory Circular(2 ) Alternating CurrentA/CAircraftACAAddress Compression AlgorithmACACAir-Cooled Air CoolerACASAirborne Collision Avoidance SystemACARSAircraft Communications Addressing andReporting SystemACARSPolled Mode An ACARS mode of operation inwhich the airborne system transmits only inresponse to received uplink messages (polls)ACC(1 ) Active Clearance Control(2 ) Area Control CenterAcclrmAccelerometerACCTSAviation Coordinating Committee fbrTelecommunications ServicesACE(1 ) The control character meaning technical acknowledge(2 ) Actuator Control Electronics(3 ) Advanced Certification EquipmentACF(1 ) Area Control Facility(2 ) ACARS Convergence Function (ARINC 622)ACIDAircraft IdentificationACIPSAirfoil and Cowl Ice Protection SystemACKThe control character meaning technicalacknowledgement of an uplink, used in anACARS SystemACKNLGEAcknowledgeACMPAlternating Current Motor PumpACMSAircraft Condition Monitoring SystemACOAircraft Certification OfficeACPAudio Control PanelACRPAircraft Certification Regulatory ProgramACS(1 ) Active Control System(2 ) Audio Control SystemACSGAeronautical Communications Sub-GroupACTActiveACU(1 ) Apron Control Unit(2 ) Antenna Control Unit(3 ) Autopilot Control UnitA/DAnalog-To-DigitalADAdministrative DomainADAComputer Programming LanguageADASAutomated Weather Observing System DataAcquisition SystemADATEAdvanced Design Adaptive Test ExecutiveADC(1 ) Air Data Computer: A computer that receivesinputs from temperature sensors as well asstatic and pitot ports. Then it generates altitude,airspeed, vertical speed and several computedtemperatures.(2 ) Analog-to-Digital ConverterADFAutomatic Direction Finder: Receiver thatprovides bearings to radio frequency transmittersin a compatible frequency range.ADIAttitude Director Indicator: A PFD display thatprovides pitch and roll information.ADIRSAir Data Inertial Reference SystemADIRUAir Data Inertial Reference UnitADL(1 ) Aeronautical Data Link(2 ) Airborne Data Loader (ARINC 615)ADLP(1 ) Airborne Data Link Protocol(2 ) Aircraft Data Link Processor (MODE-S)ADLSAeronautical Data Link ServicesADMAir Data ModuleADMSAirline Data Management SystemADNSARINC Data Network ServiceADPAir Data ProcessorADPCMAdaptive Pulse Code ModulationADRASAirplane Data Recovery and Analysis SystemADS(1 ) Air Data System(2 ) Automatic Dependent Surveillance:A surveillance technique in which aircraftautomatically provide, via data link, data derivedfrom on-board navigation and position fixingsystems, including aircraft identification, fourdimensional position and additional data asappropriate(3 ) Audio Distribution SystemADS-AAutomatic Dependent Surveillance-Address(aka ADS-C)ADS-BAutomatic Dependent Surveillance-BroadcastADS-CAutomatic Dependent Surveillance-Contract(aka ADS-A)ADSELAddress Selective. ASSR system electronicallyarranged to address each transponder selectively.Only a particular transponder will respond, thusavoiding garbling. ADSEL uses a monopulsetechnique to provide more accurate bearingmeasurement. ADSEL is compatible with DABS.(Refer to Mode S transponders.)ADSPAutomatic Dependent Surveillance PanelADSU(1 ) Automatic Dependent Surveillance System(2 ) Automatic Dependent Surveillance UnitADTNAdministrative Data Transmission NetworkADVAdvanceAECUAudio Electronic Control UnitAEECAirlines Electronic Engineering CommitteeAEGAircraft Evaluation GroupAEP(1 ) Audio Entertainment Player(2 ) Autopilot Engage PanelAERAAutomated En Route traffic controlAESAircraft Earth StationAEUAuxiliary Equipment UnitAFAirway FacilitiesAFC(1 ) Automatic Frequency Compensation(2 ) Automatic Frequency ControlAFCASAutomatic Flight Control Augmentation SystemAFCSAutomatic Flight Control SystemAFD(1 ) Adaptive Flight Display(2 ) Advanced Flight Deck(3 ) Autopilot Flight DirectorAFDCAutopilot Flight Director ComputerAFDSAutopilot Flight Director SystemAFDXAvionics Full Duplex Switched EthernetAFEPSACARS Front End Processing SystemAFIAuthority Format IdentifierAFIS(1 ) Airborne Flight Infonnation System(2 ) Automatic Flight Information ServiceAFMAircraft Flight ManualAFNATS Facilities NotificationAFS(1 ) Aeronautical Fixed Service(2 ) Airborne File Server(3 ) Automatic Flight SystemAFSSAutomatic Flight Service StationAFSKAudio Frequency Shift KeyingAFTNAeronautical Fixed TelecommunicationsAFTRCCAerospace and Flight Text Radio CoordinatingCouncilA/GAir/GroundAGACSAutomatic Ground-Air Communication System. Itis also known as ATCSS or DATA LINK.AGATEAdvanced General Aviation Transport ExperimentAGCAutomatic Gain Control. AGC is used to maintainthe output level of the receiver.AGISAir Ground Intermediate SystemAGLAbove Ground LevelAGSARINC 661 Graphics ServerAHAlert Height: A height above the runway basedon the characteristics of the aircraft and its failoperational landing system, above which aCategory III approach would be discontinued anda missed approach initiated if a failure occurred inone of the redundant parts of the fail operationallanding system, or in the relevant groundequipment.AHCAttitude Heading Computer: A computer that ispart of the AHRS. Generates information for thepitch and roll displays.AHRSAttitude/Heading Reference Systems: Systemwhich measures and outputs aircraft attitude andheading.AHSAttitude/Heading System: Either an AHRS or anIRS.AIDSAircraft Integrated Data SystemAITAdvanced Intelligence Tape - used fbr the storageof digital video and audio filesAIRACAeronautical Information Regulation and ControlAIVAccumulator Isolation ValveAIXAdvanced Interactive ExecutiveAJPSAFEPS Journal Processing SystemA/LAutolandALCAutomatic Level Control. A circuit used tomaintain the output of a transmitter regardless ofvariations in the attenuation of the system.ALEAutomatic Link EstablishmentALIAltimeterALPAAirline Pilots AssociationALS( 1 ) Application Layer Structure( 2 ) Ambient Light SensorALSIPClearALT(1 ) Airborne Link Terminal(2) Alternate(3 ) Altimeter(4 ) AltitudeALT AHCAlternate Attitude Heading ComputerAETHOLDAltitude Hold ModeAltitudeHeight determined by barometric pressureAltitude RingA continuous return across the display at a rangeequivalent to aircraft altitude (WXR)AETNAlternateALTSAltitude SelectALTS CAPSelected Altitude Capture: An autopilot flightdirector mode.ALUArithmetic and Logic UnitAMAmplitude Modulation. A signal where the carriersignal is varied in amplitude to encode voice ordata information.AMASSAirport Movement Area Safety SystemAMATAircraft Mount Alignment DetectorAMCAvionics Maintenance ConferenceAMCPAeronautical Mobile Communications PanelAMEAmplitude Modulation Equivalent. An AM typesignal that processes the modulated infonnationsignal and carrier frequency separately andthen reconstructs the two signals to make anequivalent AM signal.AMI(1 ) Airline Modifiable Information(2 ) Alpha Margin Indicator: A device that displaysthe angle of attack.AMIUArea Microphone Interface UnitAMLCDActive Matrix Liquid Crystal DisplayAMMAircraft Maintenance ManualAMP(1 ) Audio Management Panel(2 ) Avionics Modernization ProgramAMS(1 ) Apron Management Service(2 ) Avionics Management ServiceAMS(R)SAeronautical Mobile Satellite (Route) ServiceAMSSAeronautical Mobile Satellite ServiceAMTOSSAircraft Maintenance Task Oriented SupportSystem. An automated data retrieval system.AMTSAeronautical Message Transfer ServiceAMUAudio Management UnitAMUXAudio MultiplexerANCAir Navigation Commission (ICAO)AneroidCapsuleAn evacuated and sealed capsule or bellows thatexpands or contracts in response to changes inpressure.ANICSAlaskan NAS Interfacility Communication SystemANLPARINC Network Layer ProtocolANPActual Navigation Performance: Measure ofthe current estimated navigation performance,excluding Flight Technical Error (FTE).ANS(1 ) Ambient Noise Sensor(2 ) Area Navigation SystemANSIAmerican National Standards InstituteANSPAir Navigation Service ProviderANTAntennaANTCAdvanced Networking Test CenterAOAAngle Of AttackAOC(1 ) Aeronautical Operational Control(2 ) Aircraft Operational Control(3 ) Airline Operational Control(4 ) Airport Obstruction Chart(5 ) Airport Operational CommunicationsAOCCAirline Operation Control CenterAODAudio on DemandAODCAge of Data, Clock (GPS term)AODEAge of Data, Ephemeris (GPS term)AOGAircraft on GroundAOHEAir/Oil Heat ExchangerAOMAircraft Operating ManualAOP(1 ) Aeronautical OSI Profile(2 ) Airline Operational ProcedureAOPAAircraft Owners and Pilots AssociationAOPGAerodrome Operations GroupAORAtlantic Ocean RegionAOR-EAtlantic Ocean Region-EastAOR-WAtlantic Ocean Region-WestA/PAutopilot .A computer commanded system forcontrolling aircraft control surfaces.APAirport Location (ACARS/AFERS)APA(1 ) Allied Pilots Association(2 ) Autopilot AmplifierAPBAuxiliary Power BreakerAPC(1 ) Autopilot Computer(2 ) Aeronautical Public Correspondence(3 ) Aeronautical Passenger CommunicationAPIApplication Programming InterfaceAPMAircraft Personality ModuleAPMSAutomated Performance Measurement SystemAPNARINC Packet NetworkAPP(1 ) Approach Control(2 ) Autopilot PanelAppApplicationAPPRApproach: That segment of flight having to dowith final descent and landing.APRActual Performance ReserveAPRLATN Profile Requirement ListAPSAutopilot SystemAPUAuxiliary Power UnitAPUCAuxiliary Power Unit ControllerAQFAvionics Qualification FacilityAQP(1 ) Advanced Qualification Program(2 ) Avionics Qualification ProcedureA-QPSKAeronautical Quadrature Phase Shift KeyingAQSAdvanced Quality SystemARACAviation Rule making Advisory CommitteeARBArbitrary Waveform GeneratorARFAirline Risk FactorARINCAeronautical Radio, INCorporated: Corporation inwhich the U.S. scheduled airlines are the majorstockholders.ARINC-XXX Digital database protocols defined byARINC committee.ARMCArea Regional Maintenance CenterARP(1 ) Aeronautical Recommended Practice(2 ) Air Data Reference Panel(3 ) Airport Reference Point: Point in spacebased on a particular altitude, waypoint and/oroffset. The FMS makes calculations to guide theaircraft to that particular point.ARPAAdvanced Research Projects AgencyARPTAirportARRArrivalARSAutomated Radar Summary chart. These arehourly generated charts showing location andintensity of radar echoes.ARSRAir Route Surveillance RadarARTAutomatic Reserve ThrustARTTAdaptive Radar Threshold TechniquesARTCCAir-Route Traffic Control Center. Approximately20 centers cover the air traffic routes in theUnited States using numerous radars and radiocommunication sets.ARTSAutomated Terminal Radar SystemARUAudio Reproducer UnitASA(1 ) Aircraft Separation Assurance(2 ) Autoland Status Annunciator (AFDS)ASAAAC RS System Access Approval (AEEC)ASAPAviation Safety/Accident PreventionASASAircraft Separation Assurance System (AEEC)ASCIIAmerican Standard Code for InformationInterchangeASCPCAir Supply and Cabin Pressure ControllersASDAircraft Situation DisplayASDEAirport Surface Detection EquipmentASDLAeronautical Satellite Data LinkASEAltimetry System ErrorASECNAAgency for the Security of Aerial Navigation inAfrica and MadagascarASELAltitude Select: An autopilot flight/director mode.ASGARINC Signal GatewayASI(1 ) Avionics System Integration(2 ) Airplane Systems IntegratorASICApplication Specific Integrated CircuitASLSAvionics System LAN SwitchASM(1 ) Airspace Management(2 ) Autothrottle Servo Motor(3 ) Avionics Specific Module(4 ) Application Specific ModuleASN.Abstract Syntax Notation OneASOSAutomated Surface Observing SystemASP(1 ) Altitude Set Panel(2 ) Aeronautical Fixed Service (AFS) SystemsPlanning for data interchangeASPPAeronautical Fixed Service (AFS) SystemsPlanning fbr data interchange PanelA-SMGCSAdvanced Surface Movement Guidance andControl SystemsASRAirport Surveillance RadarASRSAviation Safety Reporting SystemASSAPAirborne Surveillance and Separation AssuranceProcessingASSTCAerospace Simulation and Systems Test CenterASTFAirspace System Task ForceASU(1 ) Avionics Switching Unit(2 ) Application Specific UnitASVAdvanced Super ViewASSVAlternate Source Selection ValveASTAAirport Surface Traffic AutomationAT(1 ) Air Traffic(2 ) Air TransportA/TAuto throttleATA(1 ) Actual Time of Arrival(2 ) Air Transport AssociationATCAir Traffic ControlATCAAir Traffic Control AssociationATCCAir Traffic Control CenterATCRBSAir Traffic Control Radar Beacon SystemATCSSAir Traffic Control Signaling System .A systemto provide information between the pilot and airtraffic control using the VHF communicationstransceiver in conjunction with data linkequipment.ATDActual Time of DepartureATEAutomatic Test EquipmentATFMAir Traffic Flow ManagementATHRAutothrust SystemATHSAutomatic Target Handoff SystemATIInstrument Size Unit of MeasureATIS(1 ) Air Traffic Information Service(2 ) Automatic Terminal Information Service(3 ) Automatic Terminal Information SystemATLASAbbreviated Test Language for Avionics SystemsATM(1 ) Air Traffic Management(2 ) Asynchronous Transfer ModeATMCPAir Traffic Management Concept Panel (ICAO)ATNAeronautical Telecommunications NetworkATNPAeronautical Telecommunication Network PanelATPAcceptance Test Procedure (Air Transport)ATRAir Transport RackingATS(1 ) Air Traffic Services(2 ) Air Turbine Starter(3 ) Auto throttle System(4 ) Air Transport SystemATSCAir Traffic Service CommunicationATSGFAir Traffic Services Geographic FilterATSMAir Traffic Services Message ProcessorATSUAir Traffic Services UnitATTAttitudeAUOAirspace User OperationsAUTOAutomaticAUTOTILTMechanism that automatically tilts the weatherradar.AUXAuxiliaryAVAudio-VisualAVAILAvailableAVIONICSAviation Electronics: Any group of aircraftelectronic devices.AVLANAvionics Local Area NetworkAVLCAviation VHF Link ControlAVMAirborne Vibration MonitorAVOLAerodrome Visibility Operational LevelAVPACAviation Packet CommunicationAWACSAirborne Warning and Control SystemAWASAutomated Weather Advisory StationAWGAmerican Wire GaugeAWINAviation Weather InformationAWIPSAdvanced Weather Interactive ProcessingSystemAWMAudio Warning MixerAWOAll Weather OperationsAWOPAll Weather Operations PanelAWOSAutomated Weather Observation System. Asystem that gathers surface weather informationand transmits the information to the pilot via VOR,Comm Freq or telephone lines.AZAzimuth: Distance in degrees measuredclockwise from North.BAt or Below (Altitude suffix)BACKCOURSEAn approach from the end of the runway oppositethe front localizer. Normally in this type ofapproach, there is no glideslope available.BandwidthThe difference between the highest and lowestfrequency components of a signal.B-RNAVBasic Area NavigationBAPBank Angle ProtectionBAROBarometricBaron-CorrectedAltitudePressure altitude-corrected local barometricpressure.BBBATAPType B Application to Application ProtocolBAZBack Azimuth: Same concept as Backcourseexcept, the pilot uses the Microwave LandingSystem (MLS). An MLS BAZ transmitter on theground is required.Base BandB/CBackcourseBCDBinary Coded Decimal. A coding system in whicheach digit from 0 to 9 is represented by a four bitbinary number.BCRSBack CourseBCSBlock Check Sequence. BCS is a cyclic code thatis used as reference bits in an error detectionprocess.bCSUb@ckCHANNEL SERVERBDIBearing Distance IndicatorBDMISBusiness Data Management and InvoicingBeam WidthThe beam width is the width of the beam asmeasured at the half-power points of the radiatedsignal (WXR).BearingThe direction of a point or navigational aidmeasured clockwise from a reference through360°.BEDSBoeing Electronic Delivery SystemBELBelowBEPBack-End ProcessorBEPMSBack-End Processor Management SystemBERBite Error RateBFEBuyer Furnished EquipmentBFOBeat Frequency Oscillator. An oscillator thatproduces a signal to be mixed with the receivedfrequency to produce an audible beat note, forthe purpose of decoding the Morse code identifierof an NDB. The oscillator produces frequenciesequal to the sum and difference of the combinedfrequencies.BGANBroadband Global Area NetworkBGIBus Grant Inhibit. A term used in CAPS transferbus processing.BGPBorder Gateway ProtocolBIBurn-InBiGSBilingual Ground Station (ACARS and VDML2)BinaryBase-2 counting system. Numbers include 0,1.BISBoundary Intermediate SystemBISMSBIS Management SystemBISTBuilt-In Self TestBitA binary digit. Smallest data unit in amicroprocessor system.BITBuilt-In-TestBITEBuilt-In-Test EquipmentBLBlack LabelBLK(1 ) Black(2 ) BlockBLSBezel Light SensorBMVBrake Metering ValveBNRBinaryBNSBoundary Notification System (Squitters)BOCBottom of ClimbBOMBill of MaterialBOPBit Oriented ProtocolBoresightingThe process of aligning a directional antennasystem.BP(1 ) BITE Processor(2 ) Bottom PlugBPCUBus Power Control Unitbpsbites per secondBpsBytes per secondBPSKBinary Phase Shift KeyingBRBridgeBRGBearingBRIBasic Rate InterfaceBRNAVBasic Area NavigationBRSBusiness & Regional SystemsBRTBrightnessBSCUBrake System Control UnitBSNBackbone SubnetworkBSPBoard Support PackageBSU(1 ) Beam Steering Unit(2 ) Bypass Switch UnitBTBBus Tie BreakerBTMUBrake Temperature Monitor UnitBTUBritish Thermal UnitsBWANBackup WANByteA grouping of eight bits.CCelsiusc&cCommand and Controlc&wControl and WarningCAACivil Aviation Authority. A regulatory agency in theUnited Kingdom.CAACCivil Aviation Administration of ChinaCACCaution Advisory ComputerC/A Code(1 ) Course Acquisition Code(2 ) GPS Course Acquisition CodeCACPCabin Area Control PanelCAD(1 ) Computer Aided Design(2 ) Combiner Alignment DetectorCADAGCommunications Automation and Data LinkCAEComponent Application EngineerCAFCrew Alerting FunctionCAGECommercial Avionics GPS EngineCAHCabin Attendant HandsetsCAICaution Annunciator IndicatorCalibratedAirspeedCorrected for instrument errors and errors dueto position or location of the pressure source. Atstandard sea level conditions, CAS is equal totrue airspeed (TAS).CALSEL A variation of the SELCAL system in which theSELCAL signal is combined with a special gatingtoe to produce an automatic function by thereceiver. This system is only a proposal and notyet implemented.CALVER Calibration VerificationCAM ( 1 ) Computer Aided(2 ) Cockpit Area microphone(3 ) ManufacturingCANPA Constant Angle Non-Precision ApproachCAPT CaptainCARERI Chinese Aeronautical Radio Electronics ResearchInstituteCarrier An ac signal that can be modulated by changingthe amplitude, frequency or pulse of the signal.CAS ( 1 ) Collision Avoidance System(2 ) Computed Airspeed(3 ) Crew Alerting System(4) Collins Aviation ServicesCASE Computer Aided Software EngineeringCAT ( 1 ) Categories (I, II, III) for VisibilityRequirements(2 ) Clear Air Turbulence(3 ) Computer Aided TestingCAT I Operational performance Category I. An ILSfacility providing operation down to a 60-meter(200 feet) decision height and with runway visualrange not less than 800 meters (2600 feet) and ahigh probability of approach success.CAT 1 Enhanced An ILS Approach to lower-than-standard CategoryI and in some cases to Category II, minimums,based on guidance-to-touchdown provided by aCategory Ill-capable Head-up Guidance System,per FA A Order 8400.13.CAT IIOperational performance Category IL An ILSfacility providing operation down to a 30-meter(100 fieet) decision height and with runway visualrange not less than 400 meters (1200 feet) and ahigh probability of approach success.CAT IllaOperational performance Category III a. An ILSfacility providing operation with no decision heightlimit to and along the surface of the runway withexternal visual reference during final phase oflanding and with a runway visual range of not lessthan 200 meters (700 feet).CAT III bOperational performance Category III b. An ILSfacility providing operation with no decision heightlimit to and along the surface of the runwaywithout reliance on external visual reference; andsubsequently taxiing with external visual range ofnot less than 50 meters (150 feet).CAT III cOperational performance Category III c. An ILSfacility providing operation with no decision heightlimit to and along the surface of the runway andtaxiways without reliance on external visualreference.CATEVSClear Air Turbulence Enhanced Vision SystemC-BANDThe frequency range between 4,000 and 8,000MHz.CBITContinuous Built-In-TestCBTComputer-Based TrainingCCC-CheckCCACircuit Card AssemblyCCB(1 ) Configuration Control Board(2) Converter Circuit BreakerCCD(1 ) Charged Coupled Device(2 ) Cursor Control DeviceCCIRInternational Radio Consultative CommitteeCCITTConsultative Committee International Telephoneand TelegraphCCMCommon Computing ModuleCCMSContent Compilation Management System.CCRCommon Computing ResourceCCS(1 ) Cabin Communication System(2 ) Common Communication System(3 ) Common Core SystemCCUControl and Compensation UnitCCWCounterclockwiseCD(1 ) Carrier Detect(2 ) Chrominance Difference(3 ) Compact DiscCDA(1 ) Coordinating Design Authority(2 ) Continuous Descent ArrivalCDBRCabin Data Bus RepeaterCDGConfiguration Database GeneratorCDICourse Deviation IndicatorCDLCabin Discrepancy LogCDMCollaborative Decision MakingCDMACode Division Multiple AccessCDMSCollaborative Decision Making SystemCDN(1 ) Canadian Domestic Network (VHF ACARS)(2 ) Common Data NetworkCDPContinuous Data ProgramCDRCritical Design ReviewCD-ROMCompact Disc Read-Only MemoryCDS(1 ) Cabin Distribution System(2 ) Common Display SystemCDTICockpit Display of Traffic InformationCDUControl Display Unit: An input control/displayusually part of a Flight Management System(FMS).CEPTConference Europeene des Postes etTelecommunicationsCESCabin Equipment SoftwareCEUChecklist Entry UnitCFChange FieldCFDIUCentral Fault Display Interface UnitCFDSCentralized Fault Display SystemCFITControlled Flight Into TerraincfmCubic Feet per MinuteCFMUCentral Flow Management UnitCFSCabin File ServerCGCenter of GravityCGIConnecting Gate InformationCHANChannelCHG(1 ) Change(2 ) ChargeCHIComputer Human InterfaceCHISCenter Hydraulic Isolation SystemCHOLCollins High Order LanguageCHPCourse Heading PanelCI(1 ) Cabin Interphone(2 ) Configuration ItemCIDCategory Interaction DiagramCIDBChecklist Input DataBaseCIDINCommon ICAO Data Interchange NetworkCIDSCabin Interphone Distribution SystemCIECommission Internationale de I EclairageCIOCommon Input/OutputCIS(1 ) Corporate Information System(2 ) Crew Information SystemCISSConfigurable Integrated Surveillance SystemCKCheckCKLSTChecklistCLB(1 ) Climb(2 ) Closed-Loop BooleanCLKClockCLNPConnectionless Network ProtocolCLNSConnectionless Network ServiceCloud DropletsWater or ice particles having radii smaller than0.01 cmCLPControl Law ProcessorCLRClearCLTPConnectionless Mode Transport ProtocolCM(1 ) Context Management(2 ) Configuration Management(3 ) Conflict ManagementCMA(1 ) Central Maintenance Application(2 ) Contract Maintenance AgreementCMCCentral Maintenance ComputerCMCFCentral Maintenance Computer FunctionCMCSCentral Maintenance Computer SystemCMDCommandCMF(1 ) Common Message Format(2 ) Communication Management FunctionCMM(1 ) Common Mode Monitor. A type of monitorcommon to automatic flight control systems.(2 ) Component Maintenance ManualsCMNControl Motion NoiseCMPConfiguration Management PlanCMSCabin Management SystemCMOSComplementary Metal Oxide SemiconductorCMRSCommercial Mobile Radio Service(cellular phone network)CMUCommunications Management UnitCNDBCustomized Navigation DatabaseCNESCentre national d'etudes spatialesC/NOCarrier-to-Noise Density RatioCNPComm/Nav/PulseCNSCommunication, Navigation, SurveillanceCNS/ATMCommunication, Navigation, Surveillance/AirTraffic ManagementCoasted TrackA track that is continued based on previous trackcharacteristics in the absence of surveillance datareports (TCAS).CODECCoder/DecoderCOECombiner Optical ElementCOMCockpit Operating ManualCOM/MET/OPSCommunications /Meteorological /OperationsCOMMCommunicationsCOMPCommunication Of Modification PlanCompassLocatorA low-powered radio beacon, used in conjunctionwith ILS.A compass locator has a two-letteridentification and a range of at least 15 miles.COMPCompressorCONContinuousCone ofConfusionAn inverted conical shaped area extendingvertically above a VOR ground facility that is voidof the bearing signal.CONOPSConcept of OperationsConsolanA low-frequency, keyed, CW, short baselinesystem using two antennas to radiate a daisy­shaped pattern for navigational aid purposes. Thefrequency range is in the 300 kHz region . It is inlimited use today.ContourContouroriso - contour refers to a weather radardisplay presentation that blanks the echo returnsin the center of a storm cell. The area blanked outis called contour and corresponds to the returnlevels that exceed a predetermined threshold.CONUSContinental United StatesCOPCharacter-Oriented ProtocolCOPsCommunities of PracticeCORECommon Reusable ElementsCOROUTECompany RouteCorrection(SSEC)A correction is applied to static source pressuremeasurements to partly or completely correctfor pressure errors that are caused by airflowchanges. It is computed as a function of Machand altitude based on measured errors for aparticular static system.CorrectiveAdvisoryA resolution advisory that instructs the pilot todeviate from current vertical rate (e. g. DON'TCLIMB when the aircraft is climbing). (TCAS)COSChecklist Operational SoftwareCOTPConnection Oriented Transport ProtocolCOTSCommercial Off-The-ShelfCP(1 ) Circular Polarization(2 ) Conflict Probe(3 ) Control PanelCPAClosest Point of ApproachCPASCollins Portable Access SystemCPC(1 ) Cabin Pressure Controller(2 ) Controller Pilot Communication(3 ) Cursor Position ControlePCICompact Peripheral Component InterconnectCPCIComputer Program Configuration Item. A CPCInumber identifies the configuration of a computersoftware program.CPCSCabin Pressure Control SystemCPDLCController-Pilot Data Link CommunicationsCPECircular Position ErrorCPM(1 ) Core Processor Module(2 ) Crash Protected MemoryCPNCollins Part NumberCPRCommon Processing ResourceCPRSRCompressorCPSCabin Pressure SensorCPSRContractor Purchasing System ReviewCPUCentral Processing UnitC/RCommand/ResponseCR(1 ) Change Request(2 ) Contrast RatioCRC(1 ) Cyclic Redundancy Checking(2 ) Cyclic Redundancy CodeCRESCorrosion Resistant SteelCRDCurrent Routing DomainCRDACooperative Research and DevelopmentAgreementCRM(1 ) Cockpit Resource Management(2 ) Collision Risk Model(3 ) Crew Resource ManagementCRPAControlled Reception Pattern AntennaCRRCutover Readiness ReviewCRSCourseCRTCathode Ray TubeCRUComputer Receiver UnitCRZCruiseCS(1 ) Common Service(2 ) Collins Commercial Systems EngineeringCSCCargo System ControllerCSCIComputer Software Configuration ItemCSCPCabin System Control PanelCSDBCommercial Standard Data BusCSDSCargo Smoke Detector SystemCSEUControl Systems Electronics UnitCSFCommand/Status FrameCSMACarrier Sense Multiple AccessCSMA/CDCarrier Sense Multiple Access with CollisionCSMMCrash Survivable Memory ModulesCSMUCabin System Management UnitC/SOITCommunications/Surveillance OperationalImplementation TeamCSUConfiguration Strapping Unit: A LRU used toselect installed system features on a particularaircraft.CTChromaticity ToleranceCTA(1 ) Control Area (ICAO Term)(2 ) Controlled Time of ArrivalCTAFCommon Traffic Advisory FrequencyCTAICowl Thermal Anti-IcingCTASCenter Tracon Automation SystemCTCCabin Temperature ControllerCTDCross Track DeviationCTLControl: Refers to a radio frequency controllerCTMOCentralized Air Traffic Flow ManagementOrganizationCTOLConventional Take Off and LandingCTR(1 ) Center(2 ) Control zoneCTRDConfiguration Test Requirements DocumentCTRLControlCTSClear To SendCTUCabin Telecommunications UnitCU(1 ) Channel Utilization(2 ) Combiner Unit (HUD)(3 ) Control UnitC/UTCode/Unit TestCV/DFDRCockpit Voice and Digital Flight Data RecorderCVRCockpit Voice RecorderCVRCPCockpit Voice Recorder Control PanelCW(1 ) Clockwise (cw)(2 ) Continuous Wave. A continuous train ofidentical oscillations.CWCComparator Warning ComputerCWIContinuous Wave InterferenceCWMComparator Warning MonitorCWP(1 ) Controlled Working Position(2 ) Controller Working PositionCWSControl Wheel SteeringD PSKDifferential Eight Phase Shift KeyingD&ODescription and OperationDA(1 ) Descent Advisor(2 ) Drift AngleD/ADigital-to-AnalogDABSDiscrete Addressable Beacon SystemDADCDigital Air Data ComputerDADSDigital Air Data SystemDAPDigital Service Access ProductDAPsDownlink of Aircraft ParametersDARDesignated Airworthiness Representative-Adesignation of authority by the FAA, authorizedunder FAR Part 183, Subpart C.DARPDynamic Aircraft Route PlanningDARCDirect Access Radar Channel. An independentbackup to main ATC computers.DARPADefense Advanced Research Projects AgencyDARPSDynamic Aircraft Route Planning StudyDASDesignated Alteration Station: A designation ofAuthority authorized by the FAA under FAR Part21, Subpart M.Data LinkA system that allows exchange of digital data overan RF link. ATCSS is a data link system used bythe air traffic control system. ACARS is a datalink system used by airline command, control andmanagement system , using VHF communicationfrequencies.D-ATISDigital Automatic Terminal Information SystemDAU(1 ) Data Acquisition Unit(2 ) DBS Antenna UnitDBDatabasedBDecibeldBADecibels AdjustedDBi(1 ) Decibels above isotopic circular(2 ) Decibels referenced to an isotopic antennaDBIDownlink Block IdentifierdBmDecibel(s) below 1 milliwattDBMXDatabase Management SystemDBSDirect Broadcast SatelliteDBwDecibels referenced to 1 wattdBWDecibel-WattsDBUDatabase UnitDCDirect CurrentDCADisplay and Crew Alerting systemDCASDigital Control Audio SystemDCBDemand and Capacity BalancingDCDDouble Channel Duplex. A communicationsystem using two RF channels, one channel forreceive and one channel for transmit operations,for simultaneous communication.DCEData Communications EquipmentDCGFData Conversion Gateway FunctionDCLDeparture CLearanceDCMFData Communication Management FunctionDCMSData Communication Management SystemDCN(1 ) Design Change Notice(2 ) Document Change Notice(3 ) Drawing Change NoticeDCPDisplay Control Panel: Used to operate modes ofEFIS system.DCSDouble Channel Simplex. A communicationsystem using two RF channels for non­simultaneous communication. One channelis disabled while the other channel is used totransmit.DCUData Concentrator UnitDCVDirectional Control ValveDD(1 ) Data Delivery(2 ) Data DictionaryDDA(1 ) Digital Differential Analyzer(2 ) Distance Data AdapterDDDDual Disk DriveDDIDirect Dial IndicatorDDIBDecoder Digital Interface BoxDDMDifference in Depth of Modulation, ameasurement used in conjunction with ILSsignals.DDPDeclarations of Design and Performance. Acontrol document required by the United KingdomCivil Aviation Authority (CAA) for certification ofavionics equipment.DDRDraft Document ReviewDDSDirect Digital SynthesizerDDTDownlink Data TransferDDTCData Link Delivery of Expected Taxi ClearancesDDUDisplay Drive UnitDEBDesign Eye Box. The three dimensional volume inspace surrounding the Design Eye Position fromwhich the HUD information can be viewed.DECCAA navigation system widely used by shipping inEurope. The ground facilities consist of a masterstation and several slave stations.DecimalBase-10 counting system. Numbers include 0, 1,2, 3, 4, 5, 6, 7, 8, 9.dedDedicatedDEFDARSDigital Expandable Flight Data Acquisition andRecording SystemDEFLDeflectionDEGDegreeDELDeleteDemand ModeAn ACARS mode of operation in whichcommunications may be initiated by the groundprocessor or the airborne system.DEP(1 ) Departure(2 ) Design Eye Position. The position at eachpilot's station from which a seated pilot achievesthe optimum combination of outside visibility andinstrument scan.DERDesignated Engineering Representative:Designation of authority by the FAA authorizedunder FAR Part 183, Subpart B.DESDescentDESCRDescriptionDesensitizationTCAS sensitivity level (threat volume) reductionDESDescent: An autopilot Flight director mode.DESTDestinationDEVDeviationDFDefinition FileDFADirection Finding AntennaDFCSDigital Flight Control SystemDFDAFDigital Flight Data Acquisition FunctionDFDAMUDigital Flight Data Acquisition Management UnitDFDAUDigital Flight Data Acquisition Unit. The DFDAUsamples, conditions and digitizes the flight data.DFDRDigital Flight Data RecorderDFDUDigital Flight Data UnitDFIDUDual Function Interactive Display UnitDFIUDigital Flight Instrument UnitDFSDigital Frequency SelectDFUDigital Function UnitDGDirectional Gyro: Mode of AHS operation thatprovides heading data without the benefit of a flux(AHRS) or normal alignment (IRS).DGACDirection Generate de 1'Avaiation Civile (France'sCivil Aviation Agency).DGNSSDifferential Global Navigation Satellite SystemDGPSDifferential Global Positioning SystemDH(1 ) Dataflash Header(2 ) Decision Height: Specified height in theprecision approach at which a missed approachmust be initiated if the required visual reference tocontinue the approach has not been established.DIData InterruptDIAGSDiagramsDIBDigital Interface BoxDIDData Item DescriptionDIP(1 ) Data Interrupt Program(2 ) Dual In-line Package. The most commonpackage configuration for integrated circuits.DIR(1 ) Direct(2) Director(3) DirectionDirected ModeA DME operating mode that allows an FMCS toselect one to five DME stations for inteiTogation.DIR/INTCDirect InterceptDISCDisconnectDISCHDischargeDISCRDiscrepancyDISCRETESA general term for a single wire signal that iseither off or on.DISPDisplayDISTDistanceDITSData Information Transfer SystemDL(1 ) Data Link(2 ) DownlinkDLAPData Link Application ProcessorDLCData Link Control Display UnitDLCIData Link Control IdentifierDLEData Link EntityDLGFData Load Gateway FunctionDLIData Link Interpreter programDLKData Link (AEEC)DLL(1 ) Data Link Library(2 ) Dynamic Link LibraryDLMData Link Management UnitDLMEData Link and Message EngineeringDL/MSUData Loader/Mass Storage UnitDLODSDuct Leak and Overheat DetectionDLPData Link ProcessorDLSData Load SystemDLSPData Link Service ProviderDLTDigital Lineal Tape-used for the storage of videoand audio filesDLUDownload UnitDMDisconnected ModeDMADirect Memory AccessDMEDistance Measuring Equipment. A system thatprovides distance information from a groundstation to an aircraft.DME/NAbbreviation for a DME normal systemDME/PAbbreviation fbr a DME precision systemDME SearchIn this mode, the DME scans from 0 mile tothe outer range for a reply pulse pair aftertransmitting an interrogation pulse pair.DMFData Management FunctionDMIRDesignated Manufacturing InspectionRepresentativeDMM(1 ) Data Memory Module(2 ) Digital MultimeterDMNData Multiplexing NetworkDMSDebris Monitoring SensorDMUData Management UnitDO- 60RTCA Document 160, Environmental Conditionsand Test Procedures fbr Airborne Equipment,Issued 12/04/89DO-RTCA document 178, Software Considerations inAirborne Systems and Equipment Certification,Issued 03/22/85DOADelegation Option Authorization: A delegation ofauthority authorized by the FAA under FAR Part21, Subpart J.DOCDocumentationDOCSISData Over Cable Service Interface SpecificationsDODDepartment of DefenseDOORSDynamic Object Orientated Requirements SystemDoppler EffectThe change in frequency observed at the receiverwhen the transmitter and receiver are in motionrelative to each other.DOSDisk Operating SystemDOTDepartment ofTransportationDOTSDynamic Ocean Tracking SystemDownlinkThe radio transmission path downward from theaircraft to the earth.DPDeparture ProceduresDPATBoeing Engineering Process Council DisplayProcess Action TeamDPCUDigital Passenger Control UnitDpidots per inchDPPDecision Point ProcessDPRDual Port RAMDPSKDifferential Phase Shift KeyingDQGDigital Quartz GyroDR(1 ) Data Reconing(2 ) Data Receptacle(3 ) Dead Reckoning: The worst degradedmode of FMS navigation. DR is displayed whenno raw position data is received by the FMS fbra set time delay. In such situations, position iscomputed by monitoring speed and directionsince last known position.DRERDesignated Radio Engineering Representative(FAA)Drift AngleThe angle between heading and track. It is due tothe effect of wind currents. Sometimes called thecrab angle.DRNDocument Release NoticeDSADDigital Service Access DeviceDSARCDefense System Acquisition Review CycleDSBDouble Side Band. An AM signal with the carrierremoved. Requires the same bandwidth as theAM signal.DSDUData Signal Display UnitDSFDisplay System FunctionDSP(1 ) Digital Signal Processor(2 ) Display Select Panel(3 ) Domain Specific PartDSPDRVDisplay DriverDSPYDisplay (annunciation on CDU)DSRDisplay System ReplacementDSSDecision Support SystemsDSSSDirect Sequence Spread SpectrumDSTDecision Support ToolDSU(1 ) Data Signaling Unit(2 ) Domain Service UnitDTCDesign To CostDTD(1 ) Data Terminal Display(2 ) Document Type DefinitionDTEData Terminal EquipmentDT&EDevelopment Test and EvaluationDTGDistance-to-goDTKDesired TrackDTMFDual Tone Multi-FrequencyDTMDemonstration Test MilestoneDTPDUData Protocol Data UnitDTUData Transfer UnitDUDisplay UnitDual Mode DME An airborne DMERT capable of processingDME/N and DME/P ground station signals.Operation is in the L-band frequency range.DUATDirect User Access TerminalDuplexA communication operation that uses thesimultaneous operation of the transmit andreceive equipment at two locations.DVFDemonstration and Validation FacilityDVIDigital Visual InterfaceDVMDigital VoltmeterDWANDirect WANDXDistanceDynamicPressureDynamic Pressure is the difference between pitotand static pressure.Dynamic RAMRAM constructed of capacitor elements. Memorycells must be periodically refreshed to keepcapacitors from discharging and losing data.(See “Static RAM")E(1 ) East(2 ) ElevatorEAAExperimental Aircraft AssociationEADIElectronic Attitude Director IndicatorEAFREnhanced Airborne Flight RecorderEAIEngine Anti-IceEAPEngine Alert ProcessorEAROMElectrically Alterable ROMEARSEngineering Activity Reporting SystemEARTSEn route Automated Radar Tracking SystemEASEquivalent AirspeedEASAEuropeon Aviation Safety AgencyEASIEEnhanced ATM and Mode S Implementation inEuropeEATCHIPEuropean Air Traffic Control Harmonization andIntegration ProgrammeEATMSEuropean Air Traffic Management SystemsEBACEEuropean Business Aviation Convention andExhibitionECEvent CriterionECACEuropean Civil Aviation ConferenceECAMElectronic Caution Alert ModuleECARSEnhanced ACARSECEFEarth-Centered, Earth-FixedEchoThe portion of the radiated energy reflected backto the antenna from the target (WXR).ECLElectronic ChecklistECMElectronic Control ModuleECMPElectronic Component Management SystemECONEconomy (minimum cost speed schedule)ECPEICAS Control PanelECS(1 ) Engineering Compiler System. An automateddata storage system.(2 ) Environmental Control System(3 ) Event Criterion SubfieldECSLLeft Environmental Control System CardECSMCECS Miscellaneous CardECSRRight Environmental Control System CardECU(1 ) EICAS Control Unit(2 ) Electronic Control Unit(3 ) External Compensation UnitEDEICAS DisplayE/DEnd-of-DescentEDAElectronic Design AutomationEDACError Detection and Correction (usedinterchangeably with EDC)EDCError Detection and CorrectionEDDSElectronic Document Distribution ServiceEDFCSElectronic Digital Flight Control SystemEDIEngine Data InterfaceEDIFEngine Data Interface FunctionEDIUEngine Data Interface UnitEDMSElectronic Data Management SystemEDP(1 ) Electronic Data Processing(2 ) Engine Driven Pump(3 ) Engineering Development PalletEDUElectronic Display UnitEDSElectronic Data ServicesEEElectronics Equipment (e.g. EE-Bay)EECElectronic Engine ControlEEPROMElectrical Erasable Programmable Read OnlyMemoryEEUELMS Electronics UnitEFBElectronic Flight BagEFCExpected Further ClearanceEFDElectronic Flight DisplayEFDRExpanded Flight Data RecorderEFICElectronic Flight Instrument ControllerEFIPElectronic Flight Instrument ProcessorEFISElectronic Flight Instrument SystemEFISCPEFIS Control PanelEFVSEnhanced Flight Vision SystemEGIHOExpedited Ground Initiated HandoffEELVEvolved Expendable Launch VehicleEGNOSEuropean Geostationary Navigation OverlaySystemEGPExterior Gateway ProtocolEGPWSEnhanced Ground Proximity Warning SystemEGTExhaust Gas TemperatureEHSIElectronic Horizontal Situation IndicatorEHVElectro-Hydraulic ValveEIEngine IndicationEIAElectronic Industries AssociationEICASEngine Indication and Crew Alert System: Systemthat combines engine parameters and aircraftsystem status.EICASCEngine Indication and Crew Alert System ControlsEIPIExtended Initial Protocol IdentifierEIRPEarth Incident Radiated PowerEIS(1 ) Electronic Instrument System(2 ) Engine Indication System(3 ) Entry-In-ServiceEISAExtended Industry Standard ArchitectureEIUEFIS/EICAS Interface UnitEIVFCGElectronic Logbook and Fault Correction GuideELB/ISEElectronic Logbook In-Service EvaluationELCEmitter Coupled LogicELECElectricalELEVElevationELMExtended Length MessageELMSElectrical Load Management SystemELSElectronic Library SystemELTEmergency Locator TransmitterEMElement ManagerEMC(1 ) Electromagnetic Compatibility(2 ) Entertainment Multiplexer ControllerEMEREmergencyEMGEmergencyEMIElectro-Magnetic InterferenceEMS(1 ) Emergency Medical Services(2 ) Engine Management SystemENGEngineENOCEngineering Network Operations CenterENQEnquireENRTEEn RouteE/OEngine-OutEODEnd Of DayEOMEnd Of MessageEOTEnd Of TextEPExternal PowerEPCExternal Power ContactorEPCSEngine Propulsion Control SystemE-PIREPSElectronic Pilot ReportsE-PlaneThe E-Plane is the plane of an antenna thatcontains the electric field. The principal E-Planealso contains the direction of maximum radiation.EPLDElectrically Programmable Logic DeviceEPPEnhanced Parallel PortEPREngine Pressure RatioEPROMErasable Programmable ROMEPSElectrical Power SystemEPUEstimated Position UncertaintyEQUIPEquipmentEquivalentAirspeedEquivalent Airspeed is a direct measure of theincompressible free stream of dynamic pressure.(EAS)It is CAS corrected for compressibility effects.ERPDUEcho Reply Protocol Data UnitERAEuropean Regional Airlines AssociationERBEngineering Review BoardERDEnd Routing DomainERDIEn Route Domain InfrastructureEREExternal Roll ExtrusionERP(1 ) Eye Reference Point(2 ) Enterprise Resource PlanningERPPDUEcho Reply Protocol Data UnitERQPDUEcho Request Protocol Data UnitERUEngine Relay UnitES(1 ) End System(2 ) Extended SquitterESAEuropean Space AgencyESAS(1 ) Electronic Situation Awareness System(2 ) Enhanced Situational Awareness SystemE-ScanElectronic ScanningESDElectrostatic DischargeESDSElectrostatic Sensitive Devices. Also known asESSD.ESECOTS Ethemet Switching EquipmentESHEnd System HelloESIDEngine and System Indication DisplayESISEngine and System Indication SystemESREnergy Storage/ControlESS(1 ) Electronic Switching System(2 ) Environmental Stress ScreeningESSDElectro Static Sensitive Devices. See also ESDS.ESSPEnvironmental Stress Screen ProcedureESTEstimatedESUEnvironmental Sensor UnitETElapsed TimeETAEstimated Time of Arrival: The estimated timeto arrive at some navigational position based onpresent position and estimated ground speed.ETB(1 ) End of Block (ASC II/IA5 character)(2 ) Engineering Test BandETDEstimated Time of DepartureETIElapsed Time IndicatorETMElapsed Time MeasurementETMSEnhanced Traffic Management SystemETOPSExtended Twin Engine OperationsETPEqual Time PointETRCExpected Taxi Ramp ClearancesETVSEnhanced Terminal Voice SwitchETX(1 ) End ofTransmission(2 ) Entry Task ExitEUAFSEnhanced Upper Air Forecast SystemEUPSExternal Uninterruptible Power SupplyEUREuropeanEURATNEuropean ATNEURETEuropean TransportEurOCAEEuropean Organization for Civil AviationElectronics. A regulatory agency for avionicscertification in Europe.EURO­CONTROLEuropean Organization for the Safety of AirNavigation OperationsEVEarned ValueEVMError Vector MagnitudeEVSEnhanced Vision SystemEXECExecutiveEXTExtensionExtremelyImprobableA probability of occurrence less than or equalto 1 x 10A-9 per hour of flight, or per event (e.g.takeoff, landing). (AMJ 52.1309).ExtremelyRemoteA probability of occurrence greater than 1 x10A-9 but less than or equal to 1 x 10A-7 hour offlight, or per e vent (e.g., takeoff, landing) (AMJ25.1309).FFahrenheitFAFinal ApproachFAA(1 ) Federal Aviation Administration (U.S.)(2 ) Federal Aviation AuthorityFAATCFAA Technical Center (U.S.)FAC(1 ) Flight Augmentation Computer(2 ) Final Approach CourseFADECFull Authority Digital Electronic ControlFAFFinal Approach FixFAIFirst Article InspectionFail OperationSystemSystem capable of completing the specifiedphases of an operation following the failure of anysingle system component after passing a pointdesignated by the applicable safety analysis (e.g.,Alert Height).Fail PassiveSystemSystem which, in the event of a failure, causes nosignificant deviation of aircraft.Fail Passive(CollinsAutopilot)A single failure, should not:(1 ) Cause significant displacement of the aircraftfrom its approach path or altitude loss below thenominal glidepath.(2 ) Upon system disconnection, involve any out-of-trim condition not easily controlled by the pilot.(3 ) Cause any action of the flight control systemthat is not readily apparent to the pilot, either bycontrol movement or advisory display.Fail Safe( a ) Fail safe means that the structure has beenevaluated to assure that catastrophic failure is notprobable after fatigue failure or obvious partialfailure of a single, principal structural element.( b ) Fail safe means that an Autopilot complieswith the requirements of AC25.1329-1 A.Fail Soft(CollinsAutopilot)Limited aircraft disturbance for any single fault­less than 0.4 in pitch and less than 5 deg/sec ofroll rate.Fan MarkerA marker beacon used to provide identificationof positions along airways. Standard fan markerproduces an elliptical-shaped pattern .A secondtype produces a dumbbell-shaped pattern.FANSFuture Air Navigation SystemFAPFinal Approach PointFAR(1 ) Federal Acquisition Regulation(2 ) Federal Aviation RegulationFASFinal Approach SegmentFASTFinal Approach Spacing ToolFATFactory Acceptance TestFBLFly-By-LightFBOFixed Base OperatorFBWFly-By-WireFCFoot CandlesFCAFunctional Configuration AuditFCAFFlight Data AcquisitionFC-AVFibre Channel-Audio VideoFCC(1 ) Federal Communications Commission(2 ) Flight Control ComputerFCDCFlight Critical deFCOMFlight Crew Operating ManualFCP(1 ) Flight Control Panel(2 ) Flight Control ProcessorFCS(1 ) Flight Control System(2 ) Frame Check SequenceFD(1 ) Final Data(2 ) Flight Director(3 ) Flight Dynamics(4 ) Forward DisplayFDAFFlight Data Acquisition FunctionFDAUFlight Data Acquisition UnitFDBFlight Plan Data BankFDE(1 ) Flight Detection Exclusion(2 ) Flight Deck EnhancementFDDIFiber Distributed Data InterfaceFDEPFlight Data Entry PanelFDHFlight Deck HandsetFDIFault Detection and IsolationFDIOFlight Data Input/OutputFDMFrequency Division Multiplex. A system where themessages are transmitted over a common pathby employing a different frequency band for eachsignal.FDMAFrequency Division Multiple AccessFDPSFlight Data Processing SystemFDRFlight Data RecorderFDRSFlight Data Recorder SystemFDSFlight Display SystemFDUFlux Detector UnitFEATSFuture European Air Traffic Management SystemFECForward Error CorrectionFEPFront End ProcessorFFFuel FlowFFSCFree Flight Steering CommitteeFGCFlight Guidance ComputerFGPFlight Guidance Panel: A LRU used for controllingthe modes of the flight director.FGSFlight Guidance SystemFHA(1 ) Functional Hazard Assessment/Analysis(2 ) Fault Hazard AssessmentFHSSFrequency Hopped Spread SpectrumFHWFault History WordFIBForwarding Information BaseFIFOFirst In , First OutFIMFault Isolation ManualFIRFlight Infonnation RegionFIS(1 ) Flight Information Service(2 ) Flight Information System(3 ) Flight Instrument SystemFIS-BFlight Information Services-BroadcastFIXPosition in space, usually on aircraft's flight planFL(1 ) Flight Level (as in FL4I0 ). This terminologyis used to describe aircraft attitude when thealtimeter is set at QNE.(2 ) Foot LambertFL 0Flight Level 180: The transition altitude (18,000 ft)for the United States. At this altitude, the pilot setsthe barometric correction to standard atmosphericpressure (29.92 in-Hg).FLCHFlight Level ChangeFLIRForward Looking Infra-RedFLMFlight Line MaintenanceFLTFlightFLTAForward Looking Terrain AvoidanceFLTCTRLFlight ControlFETINSTFlight InstrumentFLWForward Looking Windshear RadarFM(1 ) Frequency Modulation(2 ) Flight ManagementFMAFlight Mode AnnunciatorFMC(1 ) Flight Director Control (FD)(2 ) Flight Management Computer (FMCS)FMCFFlight Management Computer FunctionFMCSFlight Management Computer SystemFMCWFrequency-Modulated Continuous WaveFMEAFailure Mode and Effects AnalysisFMFFlight Management FunctionFMPFlight Mode PanelFMSFlight Management SystemFMUFuel Metering UnitF/0(1 ) First Officer(2 ) Fuel/Oil Cooler(3 ) Fiber OpticFOBFuel on BoardFOC(1 ) Fuel/Oil Cooler(2 ) Full Operational CapabilityFOEBFlight Operations Evaluation BoardFOGFiber Optic GyroFOQAFlight Operations Quality AssuranceFOVField Of ViewFPA(1 ) Flight Path Angle(2 ) Focal Plane ArrayFPACFlight Path AccelerationFPCFlight Profile ComparatorFPGAField Programmable Gate ArrayFPLNFlight PlanFPMFeet Per MinuteFPTAFlight Plan Target AltitudeFPVFlight Path VectorFQISFuel Quantity Indicating SystemFQPUFuel Quantity Processor UnitFQRFormal Qualification ReviewFRFromFRAFlap Retract ion AltitudeFRADFrame Relay Access DeviceFraming PulseA pulse that is used to mark the beginning or endof the coded reply pulses.FREERFree-Route Experimental Encounter ResolutionFree ScanModeA DME operating mode that will provide distancedata to all DME ground stations within the DMErange (LOS).FREQFrequencyFrequencyThe ability of a receiver-transmitter to rapidly andcontinually shift operating frequency.FRMFault Reporting ManualFRMRFrame RejectFRONT­COURSEILS approach made from the end of the runwayfbr which the localizer is calibrated. Uses bothlocalizer and the glideslope.FRPFederal Radionavigation PlanFRPAFixed Reception Pattern AntennaFRQFrequencyFSASFlight Service Automation SystemFSBFlight Standardization BoardFSEField Service EngineerFSEUFlap Slat Electronics UnitFSFFlight Safety FoundationFSSFlight Service StationFSUFile Server UnitFT(1 ) Functional Test(2 ) FeetFTEFlight Technical Error: The accuracy with whichthe aircraft is controlled as measured by theindicated aircraft position with respect to theindicated command or desired position. It doesnot include blunder errors.FTPFile Transfer ProtocolFTPPFault Tolerant Power PanelFUAFlexible Use AirspaceFWFailure WarningFWCFlight Warning ComputerFWDForwardFWSFlight Warning SystemFYDSFlight Director/Yaw Damper SystemGaAsFETGallium Arsenide Field Affect TransistorGA(1 ) General Aviation(2) Go AroundGAASGallium ArsenideGACSGenetic ATN Communications ServiceGAITGround-based Augmentation and IntegrityGAMAGeneral Aviation Manufacturers AssociationGANGlobal Area NetworkGATMGlobal Air Traffic ManagementGBASGround Based Augmentation SystemGBSTGround-Based Software ToolGbyteGigabyte (billion bytes)GCASGround Collision Avoidance SystemGCBGenerator Circuit BreakerGCCGround Cluster Controller (ACARS)GCISGlobal Component Information SystemGCPGeneric Control Panel (circuit card)GCSGround Clutter SuppressionGCUGenerator Control UnitGDLPGround Data Link ProcessorGDOPGeometric Dilution Of Precision. A term referringto error introduced in a GPS calculation due tothe positioning of the satellites and the receiver.GDPGround Delay ProgramGE4Graphics Engine 4GENGeneratorGEOGeostationary Earth OrbitGESGround Earth StationGFEGovernment Furnished EquipmentGFIGeneral Format IdentifierGFSKGaussian Frequency Shift KeyingGG(1 ) Graphics Generator(2) Ground-GroundGGMGraphics Generator ModuleGGTFMGround-Ground Traffic Flow ManagementGGRGround-Ground RouterGGSGlobal Positioning System Ground StationGHGround HandlingGHzGigahertz (billion hertz)GIGroup IdentifierGIBGNSS Integrity BroadcastGICGNSS Integrity ChannelGICBGround-Initiated Comm-BGIGOGarbage-In Garbage-OutGIHOGround Initiated HandoffGL(1 ) Ground Location (ACARS/AFEPS)(2 ) Group LengthGlidepathThe approach path used by an aircraft during aninstrument landing or the portion of the glideslopethat intersects the localizer. The glide path doesnot provide guidance completely to a touch downpoint on the runway.GlideslopeThe vertical guidance portion of an ILS system.GLNSGPS Landing and Navigation SystemGLNUGPS Landing and Navigation UnitGLONASSGlobal Navigation Satellite SystemGLS(1 ) GPS/GNSS Landing System(2 ) Gun Laying SystemGLUGPS/GNSS Landing UnitGMGuidance MaterialGMCGround Movement ControlGMTGreenwich Mean Time. GMT is a universal timescale based upon the mean angle of rotation ofthe earth about its axis in relation to the sun. Itis referenced to the prime meridian that passesthrough Greenwich, England.GMUGlobal Network ArchitectureGNDGroundGNEGross Navigational ErrorGNLSGNSS Navigator and Landing SystemGNLUGNSS Navigator and Landing UnitGNRGlobal Navigation ReceiverGNSSGlobal Navigation Satellite SystemGNSSPGlobal Navigation Satellite System PanelGNUGNSS Navigator UnitGoniometerA device that combines the two signals from twoloop antennas. The goniometer (or resolver)contains two fixed coils and one rotating coil.The rotating coil is connected to the ADFbearing indicator needle to indicate the relativebearing from the aircraft to the NDB station.The mechanical position of the rotor representsthe bearing of the station, and the position iselectrically transmitted to the RMLGOSGrade of ServiceGOSIPGovernment Open Systems InterconnectionProfileGPAGlide Path Angle: The angle between the groundand the glide path. Similar concept to glideslopeangle.GPADIRSGlobal Positioning, Air Data, Inertial ReferenceSystemGbpsGigabits per secondGPIBGeneral Purpose Instrument BusGPMGeneral Purpose ModuleGPPGeneral Purpose ProcessorGPS(1 ) Global Positioning System (See NAVSTAR)(2 ) Global Positioning SatelliteGPS LGlobal Positioning System LI FrequencyGPSSUGlobal Positioning System Sensor UnitGPUGround Power UnitGPWCGround Proximity Warning ComputerGPWSGround Proximity Warning SystemGRGround RouterGRIBGridded Binary (National Weather Service ModelOutput)GradientThe rate at which a variable quantity increases ordecreases.Gray CodeSpecial binary code used to transmit altitudedata between framing pulses of a transponderreply. A cyclic code having only one digit changeat a time. Used in Mode C to transmit aircraftbarometric altitude. Also known as Gilham code.Ground WaveA radio wave that travels along the earth'ssurface.GRPGeographic Reference PointGS(1 ) Glideslope: Radio signal that providesvertical guidance in an instrument landing.(2 ) Ground SpeedG/SGlideslope: Radio signal that provides verticalguidance in an instrument landing.GSCGround Station Controller (ACARS)GSEGround Support EquipmentGSIFGround Station Information FrameGSMGlobal Systems MobileGSMSGround Station Management SystemGSPGlare Shield PanelGSVGray Scale Voltage(s)GTGreater ThanGTAGeneral Terms AgreementGTCData Link Ground Terminal ComputerGTRGeneral Technical RequirementsGUIGraphic/User InterfaceGVEGraphics Vector EngineGW(1 ) Gateway(2) Gross WeightGWSGraphical Weather ServicesGyroscopeA rotating device that will maintain its originalplane of rotation, no matter which direct ion thegyroscope mount is turned.HADHardware Architecture Document“Halo”Means there is a thin black line (halo) aroundthe symbol or character. Haloing is used whenappropriate to allow characters and/or symbols tobe clearly seen when they are displayed against asolid background color (Such as the Sky/Ground).HALTHighly Accelerated Life TestingHAMSHot Air Management SystemHAPHGS Annunciator PanelHARSHigh Altitude Route SystemHATHeight Above TouchdownHCHGS ComputerHCP(1 ) Head-Up Control Panel(2 ) HGS Control PanelHCIHuman Computer InterfaceHCSHost Computer SystemHCUHUD Combiner UnitHCWHeavily Cold Worked Pipe and Tube(Sean-Free™)HDBKHandbookHDDHead Down DisplayHDGHeading: The angular relation of the longitudinalaxis of the aircraft with respect to a reference.Magnetic heading is referenced to magneticnorth. True heading is reference to true north.HDGSELHeading SelectHDISKHard DiskHDLHybrid Data LinkHDLCHigh-Level Data Link ControlHDLC-BHigh-Level Data Link Control-BalancedHDLMSHybrid Data Link Management SystemHDOPHorizontal Dilution of PrecisionHDOTInertial Vertical SpeedHDPHardware Development PlanHEAltitude ErrorHeadingThe direction of an aircraft path with respect tomagnetic or true north.HERFHigh Energy Radio Frequency InterferenceHF(1 ) High Frequency. The portion of the radiospectrum from 3 to 30 MHz. HF communicationsystems operate in the 2 to 30 MHz portion of thespectrum.(2 ) Human FactorsHFDLHigh-Frequency Data LinkHFDMHF Data ModemHFDRHigh Frequency Data RadioHFNPDUHigh Frequency Network Protocol Data UnitHFSHigh Frequency SystemHFSGHuman Factor Study GroupHFSNLHF Sub Network LayerHGAHigh Gain AntennaHGCHead-Up Guidance ComputerHGS(1 ) Head-Up Guidance System(2 ) HUD Guidance SystemHHLDHeading HoldHIHighHIC(1 ) Head Impact Criteria(2 ) Head Injury CriteriaHILHorizontal Integrity LimitHIRF(1 ) High Intensity Radiated Field(2 ) High Intensity Radio FrequencyHLCSHigh Lift Control SystemHLEHigher Layer EntityHLLHigh Level LanguageHMHealth ManagementHMFHealth Management FunctionHMIHuman Machine InterfaceHMOSHigh Density Metal Oxide SemiconductorHMUHeight Monitoring UnitHOHandoffHOLDHolding PatternHOWHand Over WordHP(1 ) High Pressure(2 ) Holding PatternHPA(1 ) High Power Amplifier(2 ) HectoPascal: A unit of pressure in themeter-ki 1 ogram-second system. (Hecto=100)(1 Pascal=l Newton per square meter).hPahecto PascalHPCHigh Pressure CompressorH-PlaneThe H-Plane is the plane in which the magneticfield of the antenna lies. The H-Plane isperpendicular to the E-Plane.HPRHigh-Power RelayHPRESPressure AltitudeHPSOVHigh-Pressure Shutoff ValveHPTHigh-Pressure TurbineHPUHUD Projector UnitHRDHome Routing DomainHSAHorizontal Stabilizer ActuatorHSACEHorizontal Stabilizer Actuator Control ElectronicsHS-DSADHigh Speed Frame Relay Service Access DeviceHSIHorizontal Situation Indicator. An indicator thatdisplays bearing, glideslope, distance, radiosource, course and heading information.HSITHardware and Software Integration TestHSLHeading SelectHSRHigh Stability ReferenceHSRPHot Standby Routing ProtocolHSTHigh Speed TransceiversHSTAHorizontal Stabilizer Trim ActuatorHTCHighest Two-way ChannelHUDHead-Up DisplayHVPSHigh-Voltage Power SupplyHWHardwareHWC1Hardware Configuration ItemHWNDHeadwindHW/SWHardware/SoftwareHXHeat ExchangerHYDHydraulicHYDIMHydraulic Interface ModuleHzHertz (cycles per second)I SIntegrated Information SystemIACSPInternational Aeronautical CommunicationsService ProviderI/FInterfaceIAI nternati on al Al ph abet Number 5IAGSIntegratedARINC Ground StationIANAIntemetAssigned Number AuthorityIAOAIndicatedAngle-of-AttackIAOPAInternational Council of Aircraft Owners and PilotsAssociationsIAPAInstrument Approach Procedures AutomationI APSIntegratedAvionics Processing SystemI ARPInverseAddress Resolution ProtocolIASIndicatedAirspeed is the speed indicated bya differential pressure airspeed indicator thatmeasures the actual pressure differential inthe pitot-static head. It is the actual instrumentindication for a given flight condition.IASPIAS Profile: An autopilot/flight director mode thatcommands the aircraft to fly pre-programmedairspeed values.IATAInternational Air Transport AssociationIAWIn Accordance WithIBACInternational Business Aviation CouncilIC(1 ) Integrated Circuit(2 ) IntercabinetICAOInternational Civil Aviation Organization(Montreal)ICCI APS Card CageICCAInternational Civil Certification AuthoritiesICCAIAInternational Coordinating Council of AerospaceIndustriesICD(1 ) Installation Control Drawing(2 ) Interface Control Drawing(3 ) Interactive Design CenterICMInterline Communications ManualICMPInternet Control Message ProtocolICNIAIntegrated Communication s, Navigation andIdentification AvionicsICPInitial Conflict ProbeICSSIntegrated Communication Switching SystemIFALPAICUInstrument Comparator UnitIDIdentifierIDCIndicator Display/ControlIDEIntegrated Development EnvironmentIdentThe action of the transponder transmitting anextra pulse along with its identification code (atthe request of a controller).IDIInitial Domain IdentifierIDGIntegrated Drive GeneratorIDMIntegrated Decision MakingIDPInitial Domain PartIDRPInter-Domain Routing ProtocolIDS(1 ) Ice Detection System(2 ) Integrated Display System(3 ) Information Display SystemIDUInteractive Display UnitIECI APS Environmental Control ModuleIEDInsertion Extraction DeviceIEEEInstitute of Electrical and Electronics EngineersIEPRIntegrated Engine Pressure RatioIETMInteractive Electronic Training ManualIF(if)Intermediate Frequency. A frequency to whicha signal is shifted as an in-between step in thereception or transmission of a signal.International Federation of Airline PilotsAssociationIFATCAInternational Federation of Air Traffic Controllers,AssociationsIFEIn-Flight EntertainmentIFPSIntegrated Initial Flight Plan Processing SystemIFRInstrument Flight RulesIFRBInternational Frequency Registration BoardIGAIntermediate Gain AntennaIGESStandardized Graphics Exchange FileIGIAInteragency Group on International AviationIGSIntegrated Ground SoftwareIGVInlet Guide VaneILMIndependent Landing MonitorILSInstrument Landing System. The system provideslateral, a long-course and vertical guidance toaircraft attempting a landing.IMInner Marker Beacon: When present, MB usedin conjunction with ILS, intercepts glideslopeapproximately 100 feet above touchdown.IMAIntegrated Modular AvionicsIMASIntegrated Mission Avionics SystemIMCInstrument Meteorological ConditionsIMGImplementation Management GroupIMIImbedded Message IdentifierIMOKI'm OkayIMPATT DiodeImpact Avalanche and Transmit Time. Thistype of diode, when mounted in an appropriatecavity, produces microwave oscillations andamplification.IMSIntegrated Master ScheduleIMU(1 ) Inertial Measurement Unit(2 ) IF Multiplexer Unit In InchINBD(1 ) Inboard(2) InboundINDIndicatorIndicatedAltitudeThe altitude above mean sea level (uncorrectedfor temperature).INFOInformation Framein.hg.Inches of MercuryINITInitializationINJInjectionINMARSATInternational Maritime Satellite OrganizationINOPInoperative; not working.INPHInterphoneINSInertial Navigation System. A self-contained,dead-reckoning system that senses theacceleration along the three axes of the aircraftand calculates the distance traveled froma reference point. Accuracy of the systemdecreases with respect to time.INSTInstrumentINTCInterceptInterknitInternet Network Information CenterINTERSIntersectionsIntruderAn altitude reporting aircraft that is beingconsidered as a potential threat and processedby the threat detection logic (TCAS).Inverse VideoA video display technique that surroundscharacters or digits with a color rather thancreating those characters or digits from a color(i.e., black characters are created by a redbackground rather than writing red characters).I/OInput/Output. Refers to bi-directional data ports.IOC(1 ) Initial Operational Capability(2 ) Input/Output Concentrator(3 ) Input/Output ControllerIONInstitute of NavigationIORIndian Ocean RegionIOSInternet Operating SystemIOT&EInitial Operational Test and EvaluationIP(1 ) Instructor Pilot(2 ) Intermediate Pressure(3 ) Internet Protocol(4 ) Intellectual PropertyIPACGInformational Pacific Air Traffic ControlCoordinating GroupIPBIllustrated Parts BreakdownIPC(1 ) Illustrated Parts Catalog(2 ) Integrated Processing Cabinet(3 ) Intermediate Pressure CompressorIPD(1 ) Industrial Products Division(2 ) Integrated Product DeliveryIPIInitial Protocol IdentifierIPLIllustrated Parts ListIPMIntegrated Performance ManagementIPRInternet Protocol RouterIPSIn-Plane-SwitchingIPT(1 ) Intermediate Pressure Turbine(2 ) Integrated Product TeamIRInfraredIRDIntegrated Receiver/DecoderIREInternal Roll ExtrusionIRPIntegrated Refuel PanelIRS(1 ) Inertial Reference System(2 ) Interface Requirements SpecificationIRUInertial Reference UnitISA(1 ) Industry Standard Architecture(2 ) International Standard AtmosphereISCIntegrated Systems ControllerISDNIntegrated Services Digital NetworkISDOSInformation System Design and OptimizationSystemISDSIn-Service Data SystemISHIntermediate System Hello1SLNIsolationISO(1 ) International Organization forStandardization(2 ) International Standards Organization(3 ) IsolationIso-ContourRefer to contourISOPAISO Protocol ArchitectureISQCIntersound Quality Control facility. Facility thatchecks, labels and distributes all video cassettes.ISP(1 ) Integrated Switching Panel(2 ) Internet Service ProviderISRInterrupt Service RoutineISS(1 ) Impending Stall Speed(2 ) Integrated Surveillance SystemISSNIntermediate System SubnetworkISSPUIntegrated Surveillance System Processor UnitISUInitial Signal UnitITAInstitute of Air TransportITMInformation Technology Management is theground based portion of an ADMS (See alsoEDMS).ITOIndium-Tin OxideITSIntegrated Test SystemITSEIntegrated Test and Support EnvironmentITT(1 ) Interstage Turbine Temperature(2 ) Inter-Turbine TemperatureITUInternational Telecommunications UnionIUPSInternal Uninterruptible Power SupplyIVIsolation ValveIVIInterchangeable Virtual InstrumentationIVSIInstantaneous Vertical Speed IndicatorITWSIntegrated Terminal Weather SystemJAAJoint Aviation AuthorityJARJoint Airworthiness RequirementJAR-AWOJoint Airworthiness Requirements-All WeatherOperationsJAOJet Assisted TakeoffJCDPJoint Conceptual Definition PhaseJDCPJoint Development Concept PhaseJDPJoint Definition PhaseJFETJunction Field Effect TransistorJPEGJoint Photographic Experts GroupJPSJournal Processing SystemJ/SJammer to Signal RatioJSATJoint System Acceptance TestJTAGJoint Test Action GroupJTIDSJoint Tactical Information Distribution SystemKBKilo-Bytes (thousand bytes)KBITSKilobitsKbpsKilobits per secondkb/sKilobits Per SecondKBUKeyboard UnitKeyA hand-operated switching device or the act ofoperating such a device.KGKilogramkHzKilohertz (1000 cycles per second)kmKilometerKPIKey Performance IndicatorsKPSKilobytes Per SecondktsKnotskVAKilovolt-amperekWKilowattLLeftLL-Band carrier (1575.42 MHz)LL-Band carrier (1227.6 MHz)LCivil Satellite FrequencyLAASLocal Area Augmentation SystemLabLaboratoryLADGPSLocal Area Differential GPSLANLocal Area NetworkLAPBLink Access Protocol-BalancedLATLatitudeL-BandA radio frequency band from 390 to 1,550 MHzLBSPoundsLCALayered Component ArchitectureLCCLeadless Chip CarrierLCDLiquid Crystal DisplayLCFLink Control FieldLCILogical Channel IdentifierLCMLogic Control ModuleLCNLocal Communications NetworkLCoSLiquid Crystal on SiliconLCPLighting Control PanelLCRLink Connection RefusalLCSTBLow Cost Simulation Test bedLCVSMLife Cycle Value Stream ManagementLDLower DataLDALocalizer Directional AidLDCCLeaded Chip CarrierLDGPSLocal Area Differential Global Positioning SatelliteLDOCLong Distance Operational ControlLDSLightning Detection SystemLDULamp Driver UnitLELink EstablishLEDLight Emitting DiodeLegThe section of the flight between two waypoints.LEOLow Earth OrbitingLFLow Frequency. The frequency range from 30 to300 kHz.LFDSLarge Format Display SystemLFRLow Frequency Radio RangeLGALow Gain AntennaLHPLightning HIRF ProtectionLIBLeft InboardLIMLimitLIMNATRANLimited North Atlantic Regional Air NavigationLINCSLong-Haul Interfacility Communications SystemLISNLine Impedance Stabilization NetworkLLCLogical Link ControlLLMSLiquid Level Measurement SystemLLPLeft Lower Plug. Identifies the plug on the rearconnector of an avionics unit.L/MList of MaterialsLMELink Management EntityLMILogical Management InterfaceLMMLocator Middle Marker. An NDB that is co-locatedat the same site as the 75 MHz middle markerbeacon.LMPLeft Middle Plug. Identifies the plug on the rearconnector of an avionics unit.LMTLocal Mean TimeLNALow Noise AmplifierLNAVLateral NavigationLOLowLOBLeft OutboardLOCLocalizer. The lateral guidance portion of an ILSsystem.Lock-OnThe condition that exists when the DME receivesreply pulses to at least 50 percent of theinterrogations. Valid distance information is thenavailable.LOFTLine Oriented Flight TrainingLOMLocator Outer Marker. An NDB that is co-locatedat the same site as the 75 MHz outer markerbeacon.LONLongitudeLOPLine Of PositionLORANLong Range Navigation. A system using a groundfacility composed of a master station and aslave station. The airborne receiver computesthe position of the aircraft by using two or morereceived master-slave pairs of signals. LOR AN-Aoperates at 1850, 1900, and 1950 kHz. LORAN-Coperates at 100 kHz. LORA N-A was replaced byLORAN-C in 1980.LORAN CLong Range Navigation SystemLOS(1 ) Line Of Sight(2 ) Line-Oriented SimulationLPLinear PolarizationLPCLow-Pressure CompressorLPDULink Protocol Data UnitLPTLow-Pressure TurbineLPVLocalizer Precision VerticalLRA or LRRA(1 ) Low-Range Radio Altimeter(2 ) Line Replaceable AssemblyLRCLong Range CruiseLRMLine Replaceable ModuleLRNLong Range NavigationLRRLong Range RadarLRULine Replaceable UnitLSB(1 ) Lower Sideband. The lower side band is thedifference in frequency between the AM carriersignal and the modulation signal(2 ) Least Significant BitLSCLow Speed Cues: Markings on the airspeed scaleassociated with the stall speed region.LSDLeast Significant DigitLS-DSADLow-Speed Frame Relay Service Access DeviceLS-FRADLow-Speed Frame Relay Access DeviceLSILarge Scale IntegrationLSKLine Select KeyLSNLocal SubnetworkLSPLink State PDULTCLowest Two-way ChannelLTIRLong-Term Image RetentionLTPLeft Top Plug. Identifies the plug on the rearconnector of an avionics unit.ETVSLong-Term Verification SoftwareLubber LineA fixed line placed on an indicator to indicate thefront-to-rear axis of the aircraft.LVLower Sideband VoiceLVDSLow-Voltage Differential SignalingLVDT(1 ) Linear Variable Differential Transformer(2) Linear Voltage Differential Transducer (usedwith aircraft control surface servos).LVLCHGLevel ChangeLVPSLow Voltage Power SupplyLVTOLow Visibility Take-OffLWIRLong Wavelength Infra-RedLXLightningMMach NumbermMeterMAAMaximum Authorized IFRAltitudeMACMedium Access ControllerMach NumberMach number is the ratio of the true airspeed tothe speed of sound at a particular flight condition.It is the chief criterion of airflow pattern and isusually represented by the free-stream steady­state value.MagMagneticMagneticThe bearing with respect to magnetic north.MAGYARMagnetic Variation: The difference between TrueNorth and Magnetic North.BearingMagnetic NorthThe direction north as determined by the earth'smagnetic field. The reference direct ion formeasurement of magnetic directions.MAINTMaintenanceMALDTMean Administrative and Logistics Delay TimeMANManualMAP(1 ) Missed Approach Point(2 ) Mode Annunciator Panel(3 ) Management Authorization ProcessMarker BeaconA transmitter operating at 75 MHz that providesidentification of a particular position along anairway or on the approach to an instrumentrunway. The marker beacon is continuouslytone-modulated by a 400-Hz, a 1,300-Hz ora 3,000-Hz tone. Marker beacons along aninstrument runway provide a long-course (range)guidance and design ate when an aircraft shouldbe at a certain altitude if the aircraft is followingthe glide path.M/ASIMach/Airs peed IndicatorMASPSMinimum Aviation System PerformanceStandardsMATMaintenance Access TerminalMAUModular Avionics UnitMAWPMissed Approached WaypointMAXMaximumMAX CLBMaximum engine thrust for two-engine climbMAX CRZMaximum engine thrust for two-engine cruiseMAZMLS Azimuth: A ground based radio that provideslateral guidance during an MLS landing.MBMarker BeaconMBDModel-Based DevelopmentMBEMultiple Bit ErrorMbpsMega bytes per SecondMC(1 ) Master Change(2 ) Master CautionMCAMinimum Crossing AltitudeMCBMicrowave Circuit BoardMCBFMean Cycles Between FailuresMCCMaintenance Control ComputerMCDCMultiple Condition Decision CoverageMCDPMaintenance Control Display PanelMCDUMultifunctional Control Display UnitMCEModular Cabinet EquipmentMCLMaster Caution LightMCNManufacturing Control NumberMCP(1 ) Maintenance Control Panel(2) Mode Control PanelMCTMax Continuous ThrustMCU(1 ) Modular Concept Unit (approximately1/8-ATR,Airline Transport Rack)(2 ) Motor Control Unit (used in auto throttle)(3 ) Multifunction Concept UnitMDAMinimum Descent AltitudeMDCMaintenance Diagnostic Computer: A computerthat monitors for failures of others systems.MDCRSMeteorological Data Collection and ReportingServiceMDHMinimum Descent Height. A specified height ina non-precision approach or circling approachbelow which descent must not be made withoutthe required visual reference. Minimum DescentHeight (MDH) is referenced to aerodromeelevation or to the threshold of that is more than7 feet (2 m) below the aerodrome elevation. AMDH for a circling approach is reference to theaerodrome elevation.MDLMultipurpose Data LinkMDS(1 ) Minimum Discernible Signal. The MDS is thelowest RF signal level that can be detected as avalid signal.(2 ) Maintenance Diagnostic SystemsMDTMaintenance Display TerminalMEAMinimum En route AltitudeMECMain Equipment CenterMELMinimum Equipment List. The list of equipmentthat the FAA requires be aboard and working onan aircraft before flying.MEMSMicroElectroMechanical SystemsMEOMedium Earth OrbitMESMain Engine StartMETMeteorologyMFMedium Frequency. The portion of the radiospectrum from 300 kHz to 3 MHz.MFCPMultifunction Control Display PanelMFDMultifunction DisplayMFDSMultifunction Display SystemMFDUMultifunction Display UnitMFFMixed Fleet FlyingMFITMean Fault Isolation TimeMFMMaintenance Fault MemoryMFSMedia File ServerMGPMLS Glidepath: A ground based radio thatprovides vertical guidance during an MLS landing.MGSCUMain Gear Steering Control UnitMHDMagnetic Hard DriveMHzMegahertz (1,000,000 cycles per second)MIBManagement Information BaseMIB IIManagement Information Base IIMICMicrophone. Also refers to the output signal of themicrophone.MicroEARTSMicro En route Automated Radar TrackingSystemMIDOManufacturing Inspection District OfficeMIDUMultipurpose Interactive Display UnitMILMilitaryMIL-HDBK-General Prediction of Electronic Equipment(MTBF)MILSPECMilitary SpecificationsMIL-STD-System Safety RequirementsMin(1 ) Minimum(2 ) MinutesMIPSMillion Instructions Per SecondMIRMost Important RequirementMKPMulti-function KeyPadMKR(1 ) Marker(2 ) Marker BeaconMLAManeuver Limited AltitudeMLSMicrowave Landing System: An ILS like systemthat potentially provides curved lateral pathselectable angle approach.MLWMaximum Landing WeightMM(1 ) Mass Memory(2) Middle Marker: MB used in conjunction withILS, intercepts glideslope approximately 200 feetabove touchdown.MME(1 ) Modular Mounting Enclosure(2 ) Moving Map EquipmentMMELMaster Minimum Equipment ListMMIMan-Machine InterfaceMMICMonolithic Microwave Integrated CircuitMmoThe maximum Mach number at which an aircrafthas been certified to operate.MMOMach Maximum OverspeedMMRMulti-Mode Landing System ReceiverMMSMaintenance Management SystemMMWMillimeter WaveMNMagnetic NorthMNCIDNetwork Management Category InteractionDiagramMNPSMinimum Navigation Performance SpecificationMOMagneto-OpticalMOA(1 ) Memorandum of Agreement(2 ) Military Operation AreaMOCAMinimum Obstruction Clearance AltitudeMOD(1 ) Magneto-Optical Drive(2 ) Modification(3) ModulatorMode AThe pulse format for an identification codeinterrogation of an ATC RBS transponder.Mode BAn optional mode for transponder interrogation.Mode CThe pulse format for an altitude informationinterrogation of an ATC RBS transponder.Mode DAn unassigned, optional transponder mode.Mode S(1 ) Mode Select (a transponder format to allowdiscrete interrogation and data link capability)(2 ) Selective interrogation mode of SSRMODEMModulator/De modulatorMonMonitorMOPRMinimum Operational Performance RequirementsMOPSMinimum Operational Performance SpecificationsMORAMinimum Off-Route AltitudeMOSMetal Oxide SemiconductorMOSFETMetal Oxide Semiconductor Field EffectTransmitterMOUMemorandum Of UnderstandingMP(1 ) Main Processor(2 ) Middle Plug. Identifies the plug position onthe rear connector of an avionics unit.MPCUMultiport Protocol Converter UnitMPDSMobile Packet Data ServiceMPELMaximum Permissible Exposure LevelMPUMultifunction Process UnitMRAMinimum Reception AltitudeMRBMaintenance Review BoardMRDUMultichannel Receiver/Decoder UnitMROMaintenance, Repair & OverhaulMROSEMultiple-tasking Real-time Operating SystemExecutiveMRRManufacturing Revision RequestMRTMean Response TimeMSMiHisecondm/sMeter per SecondMSASMinistry of Transportation Satellite AugmentationSystem (Japan)MSBMost Significant BitMSC(1 ) Message Sequence Chart(2 ) Member Services CenterMSCPMobile Satellite Service ProviderMSD(1 ) Mass Storage Device(2 ) Most Significant DigitMSGMessageMSIMedium Scale IntegrationMSKMinimum Shift KeyingMSLMean Sea LevelMSPMode Select PanelM-SNDCFMobile-Subnetwork Dependent ConvergenceMSPMode S Specific ProtocolMSSRMonopulse Secondary Surveillance RadarMSSSMode S Specific ServicesMSU(1 ) Mode Select Unit(2 ) Magnetic Sensor UnitMTMinimum TimeMTBFMean Time Between Failures. A performancefigure calculated by dividing the total unit flyinghours (airborne) accrued in a period of time bythe number of unit failures that occurred duringthe same time. Where total unit hours areavailable, this may be used in lieu of total unitflying hours.MTBOMean Time Between OutagesMTBR(1 ) Mean Time Between Removal(2 ) Mean Time Between Repairs. A performancefigure calculated by dividing the total unit flyinghours accrued in a period by the number of unitremovals (scheduled plus unscheduled) thatoccurred during the same period.MTBUR(1 ) Mean Time Between Unscheduled Removal(2 ) Mean Time Between Unit Replacements. Aperformance figure calculated by dividing the totalunit flying hours (airborne) accrued in a periodby the number of unscheduled unit removals thatoccurred during the same period.MTCMaintenance Terminal CabinetMTDMaintenance Terminal DisplayMTFMaintenance Terminal FunctionMTIMoving Target Indicator. This type of radar displaywill show only moving targets.MTMModule Test and MaintenanceMTMIUModule Test and Maintenance Bus Interface UnitMTSATMulti-function Transport Satellite System (Japan)MTTDAMean Time To Dispatch AlertMTTFMean Time To Failure. A performance figurecalculated by dividing the summation of times tofailure for a sample of failed items by the numberof failed items in the sample. The same itemfailing N times constitutes N failed items in thesample. This is different from mean time betweenfailures since no allowance is given to items thathave not failed.MTTMMean Time To Maintenance. The arithmetic meanof the time intervals between maintenance actions.MTTMAMean Time to Maintenance AlertMTTRMean Time To Repair. A performance figurecalculated by dividing the sum of the active repairelapsed times accrued in a period on a numberof designated items by the number of these itemsrepaired in the same period.MTTRSMean Time To Restore ServiceMTTURMean Time To Unscheduled Removal. Aperformance figure calculated by dividing thesummation of times to unscheduled removal fora sample of removed items by the number ofremoved items in the sample. This is differentfrom MTBUR since no allowance is given to itemsthat have not been removed.MUACARS Management UnitMUETMultiplierMUSMinimum Use Specification. A generic descriptionby parameter and characteristics of the testequipment and resources required for testing aunit or system.MUXMultiplexerMVAMulti-domained, Vertically AlignedMWARAMajor World Air Route AreaMW/MCMaster Warning/Master CautionMWIRMid Wavelength Infra-RedMWLMaster Warning LightNNorthNFan speedNIntermediate compressor speedN3High compressor speedN/ANot ApplicableNACANational Advisory Committee for AeronauticsNADINNational Airspace Data Interchange NetworkNAKNegative AcknowledgementNAS(1 ) National Aircraft Standard(2 ) National Airspace SystemNASANational Aeronautics and Space AdministrationNASPALSNAS Precision Approach and Landing SystemNATNorth Atlantic TracksNATANational Air Transport Association, Inc.NATCANational Air Traffic Controllers AssociationNATS(1 ) North Atlantic Track System(2) North American Telephone SystemNAT/NAM/PACNorth Atlantic/North American/PacificNAVNavigationNAVAIDNavigational Aid. A radio station (VOR) or awaypoint that assists in navigation.NavigationDatacardA medium holding the customized navigationdatabase.NAVSTARThe NAVSTAR global positioning system (GPS) isa system using 24 satellites, all reporting precisetime signals, along with location keys. Eightsatellites are in each of three 63-degree inclinedplane circular orbits at 11,000 nmi in altitude. Thesystem is used for navigation and determiningexact position.Nautical Mile(nmi)Equivalent to 6,076.1 feet, or approximately1.15 statute miles.NBAANational Business Aviation AssociationNCNumerical ControlNICNew Installation ConceptNCDNo Computed DataNCINot Currently ImplementedNCSNetwork Coordination StationNDNavigation Display. An EFIS presentationsubstituting for the horizontal situation indicator(HSI).NDB(1 ) Navigation Data Base (as stored in FMCmemory)(2 ) Non-Directional Radio Beacon. A groundstation designed specifically for ADF use thatoperates in the 190- to 550-kHz range. Transmitsa continuous carrier with either 400- or 1020-Hzmodulation (keyed) to provide identification.NDINon-Developmental ItemNENetwork ElementNEANNorth European ADS-B NetworkNEGNegativeNEMANational Electrical Manufacturers AssociationNESDISNational Environmental Satellite, Data andInformation ServiceNETNetwork Entity TitleNEXCOMNext Generation CommunicationsNEXRADNext Generation RadarNFFNo Faults FoundNGATMNew Generation Air Traffic ManagerNHHigh Pressure Gas Generator RPMNHENotes and Helps EditorNICENAT Implementation Management Group CostEffectivenessNIMSNAS Infrastructure Management SystemNIPNetwork Interface ProcessorNIRNetwork Interface RouterNIRVNetwork interface Router VDLNISNot-In-ServiceNISTNational Institute of Standards and TechnologyN-LayerN is set fbr any layer name (such as link, network,etc.) or for the initial (e. g. N-SDU means LSDUat the link layer). OSI model definition.NLLow-Pressure Gas Generator RPMNLMNetwork-Loadable ModuleNLPNetwork Layer ProtocolNLRNetherlands National Aerospace LaboratoryNLTNot Less ThanNM or NMINautical MileNMNetwork ManagementNMCNational Meteorological CenterNMCCDNetwork Management Category Class DiagramNMCDNetwork management Category DiagramNMFNetwork Management FunctionNMIRSNetwork Management Interface RequirementsSpecificationNMOSN-type Metal Oxide SemiconductorNMPNetwork Management PlanNMSNetwork Management SystemNMTNot More ThanNNN“N”s are used to represent a generic number.Typically, multiple Ns represent a frequency.NOAANational Oceanic and Atmospheric AdministrationNOCNotice Of ChangeNOCARNorth Atlantic Oceanic Concept andRequirementsNOCCNational Operations Control CenterNO COMNo Communication. A NO COM annunciationindicates that a downlink message has not beenacknowledged in an ACARS system.NOINotice of InquiryNoiseUndesired random electromagnetic disturbancesor spurious signals that are not part of thetransmitted or received signal.NOPNotification of ProblemNOPACNorth PacificNOTAMNotice to AirmenNOTUSNotice to Users (ARINC)NPANon-Precision ApproachNPDUNetwork Protocol Data UnitNPRMNotice of Proposed Rule MakingNRNetwork RouterNRDNetwork Routing DomainNRPNational Route ProgramNRZNon-Return to ZeroNSNetwork ServiceNSAPNetwork Service Access PointNSDUNetwork Service Data UnitNSEUNeutron Single Event UpsetNSSLNational Severe Storms LaboratoryNTFNo Trouble Found. (Referring to testing orcheckout of unit/module.)NTIANational Telecommunications and InformationAdministration (U.S.)NTSBNational Transportation Safety BoardNUINetwork User IdentificationNVGNight Vision GogglesNVMNon-Volatile MemoryNVRAMNon-Vblatile RAMNWSNational Weather Service. The NWS providesa ground-based weather radar networkthroughout the United States. The radar networkoperates continuously and transmits the datato the National Meteorological Center, where itcorrelates with other weather observations.OACOceanic Area Control CenterOAGOfficial Airline GuideOASOceanic Automation SystemOAT(1 ) Operational Acceptance Test(2 ) Optional Auxiliary Terminal. The OAT may bein the form of a CRT/Keyboard device capableof interfacing with other sources of data on theaircraft and supplying data to a hard copy printer.(Used in an ACARS system.)(3 ) Outside Air Temperature. The uncorrectedreading of the outside temperature gauge.Different types of gauges require different correction factors to obtain static air temperature.OATSOrbit and Attitude TrackingOBPOperational Build PlanOBS(1 ) Omnibearing Selector. A panel instrumentthat contains the controls and circuits to selectan omnibearing and determine the TO-FROMindication.(2 ) Optical Bypass SwitchOCAOceanic Control AreaOCCOperations Control CenterOCDOceanic Clearance DeliveryOCIGOceanic Communications Improvement GroupOCLOceanic CLearanceOCMOptions Configuration ModuleOCPOceanic Clearance ProcessorOctalBase-8 counting system. Numbers include 0, 1, 2,3, 4, 5, 6, 7.ODAPSOceanic Display And Planning System. Willpresent oceanic flight data to controllers in adisplay that will enable better route and altitudeassignments.ODAROrganizational Designated AirworthinessRepresentativeODIDOperational Display and Input DevelopmentODL(1 ) Optical Data Link(2) Oceanic Data LinkODNOpen Data NetworkOEMOriginal Equipment ManufacturerOEUOverhead Electronics UnitsOff-BlockTimeThe time that the aircraft leaves the gate.Off-SideSame as cross-side of the cockpit.OFPOperational Flight ProgramOFSTOffsetOGEOperational Ground EquipmentOHUOverhead Unit (HUD)OIDOutline Installation DrawingOIUOrientation/Introduction UnitOLANOnboard Local Area NetworkOLDIOn-Line Data InterchangeO&MOperating and MaintenanceOMOuter Marker Beacon: MB used in conjunctionwith ILS, intercepts glideslope approximately1400 feet above touchdown.OMDOnboard Maintenance DocumentationOMEGAA navigation system that uses two high-poweredtransmitter ground stations to broadcast acontinuous wave signal. The receiver measuresthe range difference between the two stations todetermine position.OmnibearingThe bearing indicated by a navigational receiveron transmissions from an omnidirectional radiorange (VOR).OMS(1 ) Onboard Maintenance System(2 ) Order Management SystemOMTObject Modeling TechniqueON-SIDERefers to a pilot or copilot's own side of thecockpit.OOAObject Oriented AnalysisOODObject Oriented DesignOOOIOUT-OFF-ON-IN. An OOOI event is recorded aspart of the ACARS operation. The OUT event isrecorded when the aircraft is clear of the gate andready to taxi. The OFF event occurs when theaircraft has lifted off the runway. The ON eventoccurs when the aircraft has landed. The IN eventoccurs when the aircraft has taxied to the ramparea.On-Block TimeThe time that the aircraft arrives at the gate.OPOperationalOPCOperational Program ConfigurationOPTOptimumOPASOverhead Panel ARINC 629 SystemOPBCOverhead Panel Bus ControllerOPCOperational Program ConfigurationOPEROperationOPROnce Per RevolutionOPS(1 ) Operations Per Second(2 ) Operational Program SoftwareOPSPECSOperational SpecificationsOPUOverspeed Protection UnitO-QAROptical Quick Access RecorderOROperational RequirementsORIGOriginORTOwner's Requirement TableOSOperating SystemOSCOrder Status ReportOSDSOceanic System Development SupportOSI(1 ) Open Systems Interconnection(2 ) Open System InterfaceOSIEOSI EnvironmentOSI-RMOpen Systems Interconnection Reference ModelOSPFOpen Shortest Path FirstOT&EOperational Test and EvaluationOTAOffice of Technology Assessment (U.S.)OTFPOperational Traffic Flow PlanningOTHOver The HorizonOTPOffice of Telecommunications Policy (U.S.)OTSOff-The-ShelfOVRDOverrideovsOverhead Video SystemoxyOxygenPA(1 ) Passenger Address(2 ) Power AmplifierPACPath Attenuation Compensation (Correction): Awarning annunciation of the weather radar. It tellsthe pilot there is a significant weather activity onthat bearing.PA/CIPassenger Address/Cabin InterphonePACISPassenger Address and CommunicationInterphone SystemPADPacket Assembler-DisassemblerPairedChannelsDME channels are paired with a VORTAC or ILSfrequency and are automatically selected whenthe VORTAC or ILS frequency is selected. Mostnavigation controls have this feature.PALProgrammable Array LogicPAMPulse Amplitude ModulationPAMBPressure, ambientPANS-OPSProcedures for Air Navigation Sendces-AircraftOperationsPAPIPrecision Approach Path IndicatorsPARPrecision Approach Radar. An X-band radar thatscans a limited area and is part of the ground-controlled approach system.PASPassenger Address SystemPAT(1 ) Pilot Applications Terminal(2) Primary Access TerminalPAUPassenger Address UnitPAVPresence And ValidityPAVESProgrammable Audio Video EntertainmentSystemPAWESPerformance Assessment and WorkloadEvaluationPAXPassengerPBAPush Button AnnunciatorPBDPlace Bearing/Distance (waypoint)PBIDPost Burn-In DataPBXPrivate Branch ExchangePC(1 ) Personal Computer(2 ) Printed CircuitP-CodeThe GPS precision codePCAP physical Configuration AuditPCBPrinted Circuit BoardPCCPilot Controller CommunicationPCI(1 ) Protocol Control Information. The N-PCI isexchanged between peer network members (OSIModel) to coordinate joint information.(2 ) Peripheral Computer Interface/InterconnectPCIPPrecipitationPCMPulse Code ModulationPCMCIAPersonal Computer Memory Card InterfaceAssociationPCU(1 ) Passenger Control Unit(2 ) Power Control UnitPDProfile DescentPDAPremature Descent AlertPDBPerformance Data BasePDCPre-Departure ClearancePDCUPanel Data Concentrator UnitPDDPackage Design DocumentPDDIProduct Definition Data Interface. Standardizesdigital descriptions of part configurations andproperties needed for manufacturing.PDF(1 ) Primary Display Function(2 ) Portable Document FormatPDL(1 ) Program Design Language(2 ) Portable Data LoaderP-DMEPrecision Distance Measuring EquipmentPDNPublic Data Network (CC ITT/ISD)PDOPPosition Dilution Of Precision. AGPS term forerror introduced into the GPS calculations.PDOSPowered Door Opening SystemPDRPreliminary Design ReviewPDSPrimary Display SystemPDU(1 ) Power Distribution Unit(2 ) Power Drive Unit(3 ) Protocol Data Unit. The N-PDU is acombination of the N-PCI and the N-UD orN-SDU. The N-PDU is the total information that istransferred between peer network members (OSIModel) as a unit.(4 ) Pilot Display UnitPECTPeer Entity Contact TablePEPPeak Envelope PowerPERFPerformancePerformanceIndexA relative number used to compare theperformance of different radar systems. It iscalculated from transmitter peak power, antennagain, pulse width, prf, antenna beam width andthe receiver noise figure.PERTProgram Evaluation Review TechniquePESPassenger Entertainment SystemPETPacific Engineering TrialsPETALPreliminary Eurocontrol Test of Air/Ground DataLinkPETAL IIPreliminary Eurocontrol Test of Air/Ground DataLink, Phase IIPETAL HePreliminary Eurocontrol Test of Air/Ground DataLink, Phase II ExtensionPF(1 ) Pilot Flying(2 ) Power FactorPFCPrimary Flight ComputerPFCSPrimary Flight Control SystemPFD(1 ) Primary Flight Director(2 ) Primary Flight Display. An EFIS presentationsubstituting for the ADI.PFISPassenger Flight Information SystemPFOVPrimary Field Of ViewPFRPulse Repetition Frequency. The rate at whichpulses are transmitted.PFSProduct File SetsPGAPin Grid ArrayPHAREProgram for Harmonized ATC Research inEuropePHIBUFPerformance Buffet LimitPHINOMNominal Bank AnglePHYPhysical Interface DevicePhaseModulationA signal in which the phase varies (with respectto the original signal) with the amplitude of themodulatory signal, while the amplitude of thecarrier wave remains constant. Similar to amodified frequency modulated signal.PIParameter IdentifierPIAPerformance Integrity and AvailabilityPICSProtocol Implementation ConformanceStatementsPID(1 ) Parameter Identifier(2 ) Primitive Identifier(3 ) Process IdentifierPI/OProcessor Input/OutputPIREProduction or Pipe Internal Roll ExtrusionPIREPSPilot ReportsPitot PressureThe sum of the static and dynamic pressures andis the total force per unit area exerted by the airon the surface of a body in motion.Pitot TubeA forward facing probe attached to the outside ofthe aircraft to sense the relative pressure of theaircraft moving through the atmosphere. Namedfor Henri Pitot who first used this method ofmeasuring fluid flow pressure.PLParameter LengthPLA(1 ) Power Level Angle(2 ) Programmable Logic ArrayPLGRPrecision Lightweight GPS ReceiverPLLPhase Locked LoopPLTProject Leadership TeamPMPhase ModulationPMA(1 ) Parts Manufacturing Approval(2 ) Permanent Magnet AlternatorPMATPortable Maintenance Access TerminalPMC(1 ) Provisional Memory Cover(2 ) PCI Mezzanine CardPMEProcessor/Mass Storage EquipmentPMGPermanent Magnet GeneratorPMOProgram Management OfficePMOSP-Type Metal Oxide SemiconductorPMRPrecision Multi-mode RadarPMRsProgram Management ReviewsPOSREFPMSPerformance Management SystemPN(1 ) Part Number(2 ) Pseudo NoisePNCSPerformance Navigation Computer SystemPNDPrimary Navigation DisplayPNEUPneumaticPNFPilot Not FlyingPNRPoint of No ReturnPOAPlain OldACARSPOCProof Of Concept. A Demonstration, in a fulloperational environment, of the proposedconcept, system, facilities, weather conditions,crew complement, related aircraft systems andany other relevant parameters necessary to showconcept validity. Acceptable performance, systemreliability, repeatability, and typical pilot responseto failures must be successfully demonstrated.The demonstration itself is not a certificationprogram.POIPrincipal Operations InspectorPOPPoint of PresencePORPacific Ocean RegionPOSPositionPOSINITPosition InitializationPOSIXPortable Operating System InterfacePosition ReferencePOTPotentiometerPOSTPower-On Self-TestPOTSPlain Old Telephone System/ServiceP/PAPProduct/Process Assurance PlanPPCPower PCPPDUPhysical Layer Protocol Data UnitPPIPlanned Position Indicator. A type of radar displaywhich shows aircraft positions and airways charton the same display.PPLProcessor-to-Processor Linkppmpages per minutePPM(1 ) Pulse Position Modulation(2 ) Parts Per MillionPPOSPresent PositionPPPPoint-to-Point ProtocolPPS(1 ) Packets Per Second(2 ) Precise Positioning Service(3 ) Pulse Per SecondPRProblem ReportPRAIMPredictive Receiver Autonomous IntegrityMonitoringPRAMPrerecorded Announcement MachinePRELIMPreliminary DataPRESSPressurePressureThe altitude measured above standai,d pressureAltitudelevel. Based on the relationship of pressure andaltitude with respect to a standard atmosphere.PREVPreviousPreventiveAdvisoryA resolution advisory that instructs the pilot toavoid certain deviations from current vertical rate.(TCAS)PRFPulse Repetition FrequencyPRI(1 ) Primary(2 ) Primary Rate InterfacePrimary Meansof NavigationA means of navigation which satisfies thenecessary levels of accuracy and integrity for aparticular area, route, procedure or operation.The failure of a "Primary Means” of navigationmay result in, or require reversion to a "non・normal“ means of navigation, or an alternatelevel of RNP. Qualification as a “primary means^^of navigation typically requires that ANP/EPU beless than RNP for 99.99% of the time.PRM(1 ) Precision Runway Monitoring(2 ) Proposed Rule MakingPRNPseudo Random NoisePRNAVNND-1/Precision Area NavigationPROCProcedurePROFProfilePROGProgress Page on MCDUPROMProgrammable ROMP-RNAVNND-l/Precision Area NavigationProtocolA set of rules for the format and content ofmessages between communicating processes.PROVProvisionalPROXProximityPRSOVPressure Regulating and Shutoff ValveP/RSTPress To ResetPRTRPrinterPSPower SupplyPSA(1 ) Power Supply Assembly(2) Preselect AltitudePSAAProduct Support & Assurance AgreementPSASPrimary Stability Augmentation SystemPSCPProject Specific Certification PlansPSCUProgrammable System Control UnitPSDPort Sharing DevicePSDNPacket Switched Data NetworkPSEPower Supply EquipmentPSEUProximity Sensor Electronic UnitPSIDPounds per square inch DifferentialPSIGPounds per square inch GagePSL/PSAProblem Statement Language/Problem StatementAnalyzerPSM(1 ) Power Supply Modules(2 ) Product Support ManagersPSNPacket Switching NetworkPSPPartnership for Safety PlanPSPLPreferred Standard Parts ListPSRPrimary Surveillance Radar. The part of the ATCsystem that determines the range and azimuth ofan aircraft in a controlled air space.PSSProximity Sensor SystemPSSAPreliminary System Safety AssessmentPSUPassenger Service UnitPTTotal PressurePTRProduction Test RequirementsPTCHPitch: Movement about the lateral (left to right)axis of the aircraft.PTDPerformance Test DomainPSEPacket Switching ExchangePSTNPublic Switched Telephone NetworkPTHPathPTIPacket Type IdentifierPTMPeripheral Transition Module (I/O interface forSBC)PTRProduction Test RequirementsPTSProblem Tracking SystemPTSDProduction Test Specification DocumentPTT(1 ) Post, Telephone and Telegraph(2 ) Push To Talk. Also refers to the switchingsignal that enables the transmitter.(3 ) Push To TestPTUPower Transfer UnitPVDPlan View DisplayPVParameter ValuePVCPermanent Virtual CircuitPVTPosition, Velocity, TimePWBPrinted Wire BoardsPWMPulse-Width ModulationPWRPowerPWSPredictive Windshear SystemQAMQuadrature Amplitude ModulationQARQuick Access RecorderQCQuality ControlQECQuadrantal Error CorrectorQFEA method of setting the altimeter to compensatefor changes in barometric pressure and runwayelevation. Pilot receives information from airfieldand adjusts his altimeter accordingly and it willread zero altitude at touchdown on the runway.QMQuality ManagementQMPQuality Management PlanQNEThe method of setting the altimeter to thestandard atmosphere datum-29.92 inches ofmercury (1,013.25 mb). This setting is used inthe United States airspace by all aircraft aboveFL 180.QNHThe more common method of setting the altimeterto compensate for changes in barometricpressure. Pilot receives information from airfield,adjusts his altimeter accordingly and the altimeterwill read airfield elevation at touchdown.QOPQuality Operating ProceduresQoSQuality of ServiceQRHQuick Reference HandbookQTYQuantityQUADQuadrantQuadrantalErrorError in the relative bearing caused by thedistortion of the received radio signal (RF fields)by the structure of the aircraft.R(1 ) Right(2 ) Route Tuned NAVAID(3 ) RudderRA(1 ) Resolution Advisory (generated by TCAS)(2 ) Radio Altimeter(3 ) Routing Area(4) Radio Altitude: The absolute altitude (height)above the ground. Measured by a radio altimetersystem.RAARegional Airline AssociationRabbit TracksRabbit Tracks, or running rabbits, refer to thedistinctive display produced by another (alienradar) radar system transmission.RAD(1 ) Radial(2) Radio(3 ) Rapid Application DevelopmentRadarRadio Detecting and Ranging. A system thatmeasures distance and bearing to an object.Radar MileThe time interval (approximately 12.359microseconds) required for radio waves to travelone nautical mile and return (total of 2 nmi).RadialA line of direction going out from a VOR stationmeasured as a bearing with respect to magneticnorth.RAERegional Airworthiness Engineer (Canadian)RadomeThe radome is the protective cover on the aircraftnose that fits over the weather radar systemantenna. The radome is transparent at radarfrequencies.RAFRequirements Analysis FolderRAIRadio Altimeter IndicatorRAIMReceiver Autonomous Integrity MonitoringRALTRadio Altimeter (also RA, RA DA LT, LRA, LRRA)RAMRandom Access Memory. Generally used todescribe re ad/write integrated circuit memory.RAPPSRemote Area Precision Positioning SystemRAS(1 ) Row Address Strobe(2 ) Reference Approach SpeedRCPRequired Communication PerformanceRATRAM Air Temperature is the temperature of the airentering an air scoop inlet. It is a factor in engineperformance.RCRockwell CollinsR/CRate of ClimbR-CResistor-Capacitor networkR-C&WRack Connectors and WiringRCAGRemote Center Air/Ground StationRCCRemote Charge ConverterRCERadio Control EquipmentRCFDRockwell Collins Flight DynamicsRCL(1 ) Radio Communications Link(2 ) RecallRCORemote Communications OutletRC-MAPRockwell Collins Management AuthorizationProcessRCP(1 ) Radio Control Panel(2 ) Required Communications PerformanceRCRRouting and Circuit RestoralRC-TCPRockwell Collins Technical Consistent ProcessRCURemote Control UnitRCVRReceiverR&DResearch and DevelopmentRdR-Channel used for dataRD ARARegional Domestic Air Route AreaRDC(1 ) Routing Domain Confederation(2 ) Remote Data ConcentratorRDFRouting Domain FormatRDIRouting Domain IdentifierRDMIRadio Distance Magnetic IndicatorRDPRadar Data Processing (system)RDRRadarRDSSRadio Determination Satellite ServiceRDU(1 ) Receiver/Decoder Unit(2 ) Remote Display UnitRDVRequirements Development and ValidationRDVSRapid Deployment Voice SwitchRECAPReliability Evaluation and Corrective ActionProgramREFReferenceREFLReflectionReflectivityFactor (Z)This is a measurement of the ability of a target toreflect the energy from a radar beam.RelativeBearingThe bearing of a ground station relative to thedirect ion the aircraft nose points, or the directionof an aircraft to or from an NDB.RELRelativeRemoteA probability of occurrence greater than 1 x 10A-7 but less than or equal to 1 x 10A-5 per hour offlight, or per event (e.g. takeoff, landing)REPReliability Enhancement ProgramREQ(1 ) Request(2) Required/RequirementRERResidual Error RateResolutionAdvisoryA display indication given to the pilotrecommending a maneuver to increase verticalseparation relative to an intruding aircraft. Aresolution advisory is also classified as correctiveor preventive.RESTRRestrictionRESYNCINGResynchronizingRET(1 ) Rapid Exit Taxiway(2 ) Reliability Evaluation TestREURemote Electronics UnitRFRadio Frequency. A general term for the range offrequencies above 150 kHz, to the infrared region(1012 Hz).RFCRequest for CommentsRFDReconfigurable Flight DeckRFI(1 ) Radio Frequency Interference(2 ) Request For InformationRFPRequest For ProposalRFSIVVRequirements Functional allocation SynthesisIntegration Verification ValidationRFTPRequest For Technical ProposalRFURadio Frequency UnitRGBRed/Green/BlueRGCSPReview of the General Concept of SeparationPanelRHRadio HandlerRHIRange and Height IndicatorRHOResponse on HandoffRHSMReduced Horizontal Separation MinimaRIB(1 ) Right Inboard(2 ) Routing Information BaseRIPRouting Information ProtocolRIPSRecorder Independent Power SupplyRISCReduced Instruction Set ComputerRIURadio Interface UnitRJRegional JetR/LRed LabelRARadio AltitudeRLDRijksluchtvaartdienst (The Netherlands' CivilAviation Agency)RLEResponse on Link EstablishmentRLGRing Laser GyrosRLIRelative Location IndicatorRLPRing Laser GyroRLS(1 ) Reliable Link Source(2 ) Remote Light SensorRLYRelayR&MReliability and MaintainabilityRM&AReliability Maintainability and AvailabilityRMARemote Maintenance AccessRMIRadio Magnetic IndicatorRMMSRM Management SystemRMP(1 ) Radio Management Panel(2 ) Remote Maintenance PanelRMTRemoteR-NAVArea NavigationRNGRangeRNGARange ArcRNPRequired Navigation Performance. A statementof the navigation performance necessary foroperation within a defined airspace.RNRReceive Not ReadyRNTPRadio Nav Tuning PanelRO(1 ) Radio Operator(2 ) Roll OutROARecognized Operating AgencyROBRight OutboardROC(1 ) Rate Of Climb(2 ) Rate of Operational CapabilityRODRate Of DescentROLRollROLLMovement about the longitudinal (front to back)axis of the aircraft.RolloutRollout starts from the first contact of the wheelswith the runway and finishes when the airplanehas slowed to a safe taxi speed (in the order of30 knots).ROM(1 ) Read Only Memory(2) Rough Order of MagnitudeRONRemain Over NightROTRunway Occupancy TimeROTHRRelocatable Over-The-Horizon RadarROUTEAn ordered group of flight reference points(Airports, Navaids, Geographic Reference Points,etc.) representing part or all of a planned flightpath.RPRouting ProtocolRPDURemote Power Distribution UnitRPIRapid Process ImprovementRPMRevolutions Per MinuteRPOARecognized Private Operation Agency (COTT)RRReceiver ReadyRRIRouter Reference ImplementationRSDPReliable Sequencing Delivery ConfirmationProtocolRSNRegional SubnetworkRSP(1 ) Required Surveillance Performance(2 ) Reversion Switch PanelRSSIReceived Signal Strength IndicatorRT(1 ) Radio Telecommunication(2 ) Receiver-Transmitter (R/T). Also referred toas a transceiver. (See T/R)RTA(1 ) Receiver-Transmitter Antenna(2 ) Required Time of ArrivalRTCRTCARTCADO- 60RTCADO-RTERTFRTIRTMRTPRTORTOSRTPRTRRTSRTSPRTSSRTTIRTUReal-Time ClockRadio Technical Commission for AeronauticsRTCA Document 160, Environmental Conditionsand Test Procedures for Airborne Equipment,Issued 12/04/89RTCA Document 178, Software Considerationsin Airborne Systems and Equipment Certification,issued 03/22/85RouteRadio telephonyReal-Time InterrogateRadio Transmission ModuleReliability Test PlanRejected TakeoffReal-Time Operating SystemRadio Tuning PanelRemote Transmitter Receiver Site(1 ) Request To Send(2 ) Real-Time StudioRequired Total System PerformanceRotable Total Service SolutionsRun-Time Type IdentificationRadio Tuning Unit: A control for tuningcommunication and navigation radios.RTWReal-Time WorkshopRURack UnitRunwayIncursionThe act of inadvertently crossing the runwayholding point without ATC clearance.RVDTRotary Voltage Differential TransducerRVRRunway Visual RangeRVSMReduced Vertical Separation MinimumR/WRead/WriteRWRunwayRWMRe ad-Write Memory. A memory in which each cellis selected by applying appropriate electrical inputsignals, and the stored data may be either sensedat the appropriate output terminal or changes inresponse to other electrical input signals.RWSReactive Windshear SystemRWYRunwayRxReceiverRZReturn to ZeroSSouthSOSegment 0SSegment 1SA(1 ) Selective Availability(2 ) Situation AwarenessSAAService Access Area (VHF Cat B ACARS)SAAARSpecial Aircraft/Aircrew Authorization RequiredSAARUSecondary Attitude Air Data Reference UnitSAESociety of Aeronautical EngineersSAISystem Architecture and InterfaceSALSystem Address Label (ARINC 429)SAMASmall Aircraft Manufacturers AssociationSAPService Access PointsSARSearch and RescueSARPSStandards And Recommended Practices (ICAO)SAS(1 ) Stability Augmentation System(2 ) Station Address SetSAT(1 ) Static Air Temperature is the total airtemperature corrected fbr the Mach effect.Increases in airspeed cause probe temperatureto rise presenting erroneous information. SAT isthe outside air temperature if the aircraft could bebrought to a stop before measuring temperatures.(2 ) System Acceptance TestSATCOMSatellite CommunicationsSATNAVSatellite NavigationSBService BulletinSBASSpace Based Augmentation SystemSBCSingle Board ComputerSBDSchematic Block DiagramSBESingle Bit Errors/cStep ClimbscSpecial CommitteeSCAN ANGLEAngle of the weather reflectivity information withrespect to the aircraft heading.SCATSpecial CategorySCAT-Special Category 1 Approach SystemSCD(1 ) Specification Control Drawing(2 ) System Category DiagramSCDUSatellite Control Data UnitSCEServicing Customers EngineerSCIDSoftware Configuration Index DrawingSCIURadio Altimeter IndicatorSCMSoftware Configuration ManagementSCPCSingle Carrier Per ChannelSCQASupply Chain Quality AssuranceSCRSpecial Certification ReviewSCSSingle Channel Simplex. A communicationsystem that uses simplex.SCSISmall Computer System InterfaceSCTSystem Configuration TableSCU(1 ) Signal Conditioning Unit(2 ) Signal Conversion UnitSD(1 ) Side Display(2 ) Storm Detection. It is the designation forthe hourly transmitted radar observations fromthe NWS and ARTCC radars. Individual SDsSELCALare combined and transmitted once an hour ascollectives ( SDUs) over the aviation teletypecircuits.SD&AHWGSystem Design & Analysis HarmonizationWorking GroupSDD(1 ) Standard Disk Drive(2 ) Sensor Display Driver(3 ) System Description DocumentSDFSimplified Directional FacilitySDISource Destination Identifier: A bit field containedin serial data words that tell the source ordestination of the data in that word.SDM(1 ) Speaker Drive Module(2 ) Service Delivery ManagementSDPSurveillance Data ProcessingSDRAMSynchronous Dynamic Random Access MemorySDRLSupplier Data Requirements ListSDU(1 ) Satellite Data Unit(2 ) Sensor Display Unit(3 ) Service Data UnitSEBSeat Electronics BoxSECSecondarySEDSecondary EICASD is playSEI(1 ) Software Engineering Institute(2 ) Standby Engine IndicatorSEL(1 ) Select(2 ) Selector IdentifierSelective Calling System. A system used inconjunction with HF and VHF communicationsystems that allows a ground-based radiooperator to call a single aircraft or group of aircraftwithout the aircraft personnel monitoring theground station radio frequency.SENSSensorSensitivityLevelCommandAn instruction given to the TCAS equipment forcontrol of its threat volume.SEPCSecondary Electrical Power ContactorSEPPStress Evaluation Prediction ProgramSERNOSerial NumberSEU(1 ) Single Event Upset(2 ) Seat Electronics UnitSFARSpecial Federal Aviation RegulationSFDFSubsystem Fault Detection FunctionSFESupplier Furnished EquipmentSGSignal GeneratorSGMLStandard Generalized Markup Language.SGSSurface Guidance SystemSI(1 ) Selective Interrogation(2 ) Standby Instruments(3 ) Supporting Interrogator(4 ) Supplementary InformationSIAPStandard Instrument Approach ProcedureSICASSecondary Surveillance Radar Improvements andCollision Avoidance SystemSICASPSecondary Surveillance Radar ImprovementsAnd Collision Avoidance System PanelSIDStandard Instrument DepartureSidetoneThe reproduction of sounds in a headset (orspeaker) from the transmitter of the samecommunication set. This allows a person to hearhis/her own voice when transmitting.SIF(1 ) Standard Interchange Format(2 ) System Integration FacilitySIGMETSSignificant Meteorological ObservationsSIL(1 ) Systems Integration Lab(2 ) Service Information LetterSimplexA communication operation that uses onlya single channel for transmit and receiveoperations. Communications can take place inonly one direction at a time.SINADSignal-plus-Noise-plus-Distortion to Noise-plus-Distortion-RatioSIPSingle In-line PackageSITASociete Internationale de TelecommunicationsAeronautiquesSITP/DSystem Integration Test Plan/DescriptionSITSystem Integration and TestSITRSystem Integration Test ReportSIUSatellite Interface UnitSKPSkipSkywaveA radio wave that is reflected by the ionosphere.Depending upon the state of the ionosphere, thereflected radio wave may propagate along thelayer of the ionosphere or be reflected at someangle. It is also known as ionospheric or indirectwave.SLSensitivity LevelS/LSub-LevelSLAService Level AgreementSlant RangeThe line-of-sight distance from the aircraft to aDME ground station.SLCSynchronous Link ControlSLHSystem Level HealthSLISystem Level InterfaceSLMStandard Length MessageSLoCSource Lines of CodeSLSSide-Lobe Suppression. A system that preventsa transponder from replying to the side-lobeinterrogations of the SSR. Replying to side-lobeinterrogations would supply false replies to theATC ground station and obscure the aircraftlocation.SLUCSystem Level Use CaseSLV(1 ) Service Level Verifier(2 ) Sync Lock ValveSMSystem MonitorSMASurface Movement AdvisorSMCSystem Management and CommunicationSMDSurface Mount DeviceSMDSSwitched Multi-megabit Data ServiceSMESystem Management EntitySMGCSSurface Movement Guidance and ControlSystemsSMIStandard Message IdentifiersSMLSSeamless Pipe and TubeSMSSpectrum Monitoring SystemSMT(1 ) Aileron/Rudder Servo Mount(2 ) Elevator Servo Mount(3 ) Servo Mount(4 ) Stabilizer Trim Servo Mount(5 ) Standard Message Text(6 ) Station Management(7 ) System Maintenance TaskSNSubnetworkSNASystem Network ArchitectureSNACSubnetwork AccessSNAcPSubnetwork Access ProtocolSNCRSubnetwork Connection ReferenceSNDCFSubnetwork Dependent Convergence FunctionSNDCPSubnetwork Dependent Convergence ProtocolSNICFSubnetwork Independent Convergence FunctionSNLESubnetwork Link EstablishmentSNMPSimple Network Management ProtocolSNPASubnetwork Point of AttachmentSNPDUSubnetwork Protocol Data UnitSNRSignal-to-Noise RatioSNSDUSubnetwork Service Data UnitSOFSafety Of FlightSOHStart of HeaderSOISystem Operator InstructionsSOITSatellite Operational Implementation TeamSOMSoftware Operator ManualSONStatement of Operational NeedSOPStandard Operating ProcedureSOPAStandard Operating Procedure AmplifiedSOSSilicon On SapphireSOWStatement Of WorkSPSpaceSPATESpecial Purpose Automatic Test EquipmentSPCStatistical Process ControlSPDSpeedSPESeller Purchased EquipmentSpeed of LightRepresented by the symbol c and has a valueof 2.9979250 x 108 meters/second or983,571,194 feet/second.SPISpecial Position IdentificationSPIPDesignation fbr a transponder ident pulse.SPKRSpeakerSPM(1 ) Stabilizer Position Modules(2 ) Surface Position Monitor(3 ) Support Plan ManagerSpokingRefers to a display presentation that radiatesoutward from the display origin like the spokes ona wagon wheel.SPRSync Phase Reversal. (Term is used in Mode Stransponders.)SPS(1 ) Sensor Processing Subsystem(2 ) Standard Positioning ServiceSQ or SqlSquelchSQService QualitySQBService Quality/Billing ProcessorSQDService Quality DataSQLStructured Query LanguageSQPSignal Quality ParameterSquall LineA squall line is a line of thunderstorms anddeveloping thunderstorms.SquawkReply to interrogation signal (XPD).SquelchA control and/or circuit that reduces the gain inresponse of a receiver. The squelch is used toeliminate the output noise of the receiver when asignal is not being received.Squitter(1 ) The random pulse pairs generated by theground station as a filler signal.(2 ) The transmission of a specified replyformat at a minimum rate without the need to beinterrogated. (Filler pulses transmitted betweeninterrogations) [XPD].(3 ) Spontaneous Transmission generated onceper second by transponders.SRService RequestSRADDSoftware Requirements And Design DescriptionSRAMStatic Random Access MemorySRDSystems Requirements DocumentSREJSelective RejectSRMSelective Reject ModeSRNShort Range Navigation-term used to encompassVOR/LOC/DME/MB Navigation, or a sub-setthere-of.SRPSelected Reference PointSRRSatellite Recognition ReceiverSRTSatellite Receiver TransmitterSRUShop Replaceable Units/sShipSetSSASystem Safety AssessmentSSBSingle Sideband. An AM signal that has areduced carrier, with the power applied to a singlesideband. Since the bandwidth of the information­carrying signal is reduced, a better signal-to-noiseratio is obtained at the receiver.SSCV/DRSolid-State Cockpit Voice/Data RecorderSSCVRSolid-State Cockpit Voice RecorderSSECStatic Source Error CorrectionSSFDRSolid-State Flight Data RecorderSSMSign Status Matrix: Aset of bits in an ARINC labelthat tell the status of that label. The status can benormal, fail, test or no computed data (NCD).SSPSystem Signal ProcessorSSRSecondary Surveillance Radar. A radar-typesystem that requires a transponder to transmit areply signal.SSSCSingle Sideband Suppressed Carrier. A SSSCsignal is a band of audio intelligence frequenciesthat have been translated to a band of radiofrequencies without distortion of the intelligencesignal.SSUSubsequent Signal UnitSTStatisticsstaStationSTABStabilizerStandardAtmosphereRepresents the mean or average properties ofthe atmosphere. At sea level static pressure is29.92 In Hg and temperature is +15℃.Standby ModeA DME mode that applies power to the DMERTbut the unit does not transmit.STARStandard Terminal Arrival RoutesSTARS(1 ) Standard Terminal Automation ReplacementSystem(2 ) Status Tracking And Reporting SystemStatic PortsFlush-mounted openings in the skin of the aircraftfuselage used to sensestatic pressure.Static PressureAmbient atmospheric pressure or static pressureis the force per unit area exerted by the air on thesurface of a body at rest relative to the air.Static RAMRAM constructed of bistable transistor elements.Memory cells do not require refreshing. (SeeDynamic RAM.)Static SourceError (SSEC)A correction applied to static source pressuremeasurements to partly or completely correctfor pressure errors that are caused by airflowchanges. It is computed as a function of Machand altitude based on measured errors for aparticular static system.STBSystems Test BedSTBYStandby InstrumentsSTC(1 ) Sensitivity Time Control. A control circuitused in radar applications to control receiver gainwith respect to time.(2 ) Supplemental Type CertificateSTCMStabilizer Trim Control ModuleSTD(1 ) Standard(2 ) System Technical DescriptionSTDBYStandby InstrumentsSTDMASynchronized Time Division Multiple AccessSTEPCLBStep ClimbSTIM XXAn AHRS test mode, where "XX” can be OA(Sequence of all tests), 01 (Roll tests), 02 (Pitchtests), 03 (Heading test).STIUSatellite Telecommunications Intermediate UnitSTMSerial Transition ModuleSTOLShort Takeoff and LandingSTPStandard Temperature and PressureSTRSystem Trouble ReportSTSStable Time SubfieldSTXStart of TextSUSignal UnitSUASpecial Use AirspaceSULYaw Damper ActuatorSUO(1 ) Aileron/Elevator/Rudder Servo(2) Servo ActuatorSuper­heterodyneReceiverA receiver in which the incoming RF signal ismixed to produce a lower intermediate frequency.SuppressorPulseA pulse used to disable L-band avionics duringthe transmitting period of another piece of L-bandairborne equipment. It prevents the other avionicsaboard the aircraft from being damaged orinterfered with by the transmission and any noiseassociated with that transmission.SUPPSRegional Supplementary ProceduresSUT(1 ) Autothrottle Servo(2 ) Stabilizer Trim Servo(3 ) System Under TestSVSpace VehicleSVC(1 ) Service(2 ) Switched Virtual CircuitSVDUSmart Video Distribution UnitsvoServoSVRRService Readiness ReviewSVSSynthetic Vision SystemSVTServo ThrottleSVUSatellite Voice Units/wSoftwareSWAPSevere Weather Avoidance ProgramSWIMSystem Wide Information ManagementSWIRShort Wavelength Infra-RedSWITSoftware Integration and TestSWRDSoftware Requirements DocumentSWTRRSoftware Test Readiness ReviewSXGASuper Extended Graphics ArraySYNCSynchronizingSVASynthetic Vision ApplicationsysSystemSYSSystem IdentifierSYSCAT-BSystem Category B (FAA Message Format)SYSCISystem Configuration ItemTATraffic Advisory: TCAS information given to thepilot pertaining to the position of another aircraftin the immediate vicinity.TAD(1 ) Terrain Awareness Display(2 ) Transport Airplane DirectorateTAC(1 ) Test Access Control(2 ) Thrust Asymmetry Compensation(3 ) Triacetate CelluloseTACANThe Tactical Air Navigation System that providesazimuth and distance information to an aircraftfrom a ground station (similar to VOR-DME,however, in the UHF Frequency band).TachTachometerTACIUTest Access Control Interface UnitTAFTerminal Area Forecast (ICAO)TAIThermal Anti-IcingTAP(1 ) Terminal Area Productivity(2 ) Tailored Arrival ProcedureTARTrials ATN RouterTargetAn aircraft within the surveillance range of TCAS.TASTrue AirspeedTAT(1 ) Total Air Temperature. The air temperatureincluding heat rise due to compressibility.(2 ) True Air TemperatureTATCATerminal Air Traffic Control AutomationTAUTAU is the minimum time a flight crew needs todiscern a collision threat and take evasive action.It represents the performance envelope (speedand path of aircraft) divided by the closure rate ofany intruder aircraft (TCAS).TAWSTerrain Awareness Warning SystemTBBTransfer Bus BreakerTBDTo Be DeterminedTBOTime Between OverhaulsTBS(1 ) To Be Specified(2 ) To Be SuppliedTC(1 ) Transport Connection(2 ) Type CertificateT/CTop-of-ClimbTCA(1 ) Terminal Control Area(2 ) Throttle Control AssemblyTCASTraffic Alert Collision Avoidance System:Transponder system that talks to other aircraftand determines their altitude, rate, vertical speed,distance and bearing.TCAS IA baseline system that provides a warning (TA) tothe flight crew of the presence of another aircraft(potential collision threat) within the surveillancearea. No avoidance maneuver is suggested.TCAS IIA collision avoidance system providing trafficinformation (within approximately 30 nmi ofthe aircraft) to the flight crew, in addition to theresolution advisories (RA) (for vertical maneuversonly). ATCAS Il-equipped aircraft will coordinatewith TCAS Il-equipped intruder aircraft to providecomplementary maneuvers.TCCTurbine Case CoolingTCDSType Certificate Data SheetTCFTerrain Clearance FloorTCMTechnical Coordination MeetingTCMSTest Content Management SystemTCNTACANTCPTransmission Control ProtocolTCPIPTransport Control Protocol/Internet ProtocolTCQThrottle Control QuadrantTCSTouch Control SteeringTCU(1 ) TACAN Control Unit(2 ) Telephone Conversion UnitTCXOTemperature Controlled Crystal OscillatorT/DTop-of-DescentTDTraffic Display: A feature of the TCAS that showsTCAS traffic.TDLSTower Data Link SystemTDMIn the Time Division Multiplex Systems a commoncarrier is shared to transmit multiple messages(to multiple receivers) by time sharing the carrierbetween the message sources.TDMATime Division Multiplex Access. When multipletransmitters are using a single carrier to transmitto a single receiver, the carrier is time sharedbetween each of the transmitters, so the multiplemessages are not garbled at the receiver.TDOPTime Dilution Of Precision. A term used todescribe the error introduced by variances in thecalculated time.TDRTransponderTDRSTactical Data Radio SystemTDSTerminal Display SystemTDSTTower Data Services TerminalTDWRTerminal Doppler Weather RadarTDZTouch Down ZoneTETest EquipmentTECThermo-Electric CoolerTEIText Element IdentifiersTEMPTemperatureTemperatureProbeA sensor protruding into the airstream to senseair temperature. Requires correction to get staticair temperature.TERMTerminalTERPS(1 ) Terminal En Route Procedures(2 ) Terminal Instrument ProceduresTESTrials End System (for ATN)TF3Task Force 3TFCTrafficTFMTraffic Flow ManagementTFOVTotal Field Of ViewTFRTemporary Flight RestrictionTFTThin Film TransistorTFTPTrivial File Transfer ProtocolTFTSTerrestrial Flight Telephone SystemTG(1 ) Timer-VDL Management Entity(2 ) Transmission GateTG3GS's Maximum Time Between TransmissionsTG4Maximum Time Between GSIF's TimerTGCTurbulence Gain ControlTGSMaximum Link Overlap TimerTGTTarget: A weather radar annunciator that indicatesweather ahead.THDGTrue HeadingTHLDThresholdTHRThrustTHRHOLDThrottle HoldThreatA target that has satisfied the threat detectionlogic and thus requires a traffic or resolutionadvisory (TCAS).THSATrimmable Horizontal Stabilizer ActuatorTIA(1 ) Telecommunications IndustryAssociation(2 ) Type Inspection Authorization.TIASTrue IndicatedAirspeedTIRType Inspection ReportTISTraffic Information ServiceTIS-BTraffic Information System-BroadcastTKTrack AngleTKETrack Angle ErrorT/LTop-LevelTLTerminal Location (ACARS/AFEPS)TLAThrust Lever AngleTLCTarget Language CompilerTLMTelemetry WordTLSTarget Level of SafetyTMTimer-Media Access ControlTMATraffic Management AdvisorTMCThrust Management ComputerTMCFThrust Management Computer FunctionTMCSThrust Management Computer SystemTMFThrust Management FunctionTMS(1 ) Thrust Management System(2 ) Traffic Management SystemTMUTraffic Management UnitTN(1 ) True North(2 ) Twisted NematicTOTake OffTOC(1 ) Top of Climb(2 ) Transfer of CommunicationsTODTop of DescentTO EPRTakeoff Engine Pressure RatioTO/FROMIndicatorIndicates whether the omnibearing selected is thecourse to or from the VOR ground station.TOGATake Off, Go-Around. Also seen as TO/GA.TONTake Off Engine Fan SpeedTORTerms of ReferenceTOTTotalTouchdownThe point at which the predetermined glide pathintercepts the runway.TOWTime Of WeekTPMUTire Pressure Monitor UnitTPTest PointTP4Transport Protocol Class 4TPDUTransport Protocol Data UnitTPLTerminal Permission List (ACA RS/AFE PS)TPMTechnical Performance ManagementTPRTransponderTQAThrottle Quadrant AssemblyTRTemporary Revision. A document, printed onyellow paper that temporarily amends a page orpages of a component maintenance manual.T/R(1 ) Thrust Reverser(2 ) Transceiver (see RT)(3) Transmitter-ReceiverTRA(1 ) Temporary Reserved Airspace(2 ) Thrust Reduction AltitudeTRACTerminal Radar Approach ControlTrack(1 ) The actual path, over the ground, traveled byan aircraft (navigation).(2 ) In this mode the DME transmits a reducedpulse pair rate after acquiring lock-on (DME).(3 ) Estimated position and velocity of a singleaircraft based on correlated surveillance datareports (TCAS).TRACONTerminal Radar Approach ControlTRACSTest and Repair Control System. An automateddata retrieval system. TRACS functions include:1) provide the location of any given unit at anytime; 2) provide an efficient flow of work to andfrom test stations; 3 ) provide quick access toquality information generated by the actual testingprocess (performed by the technician); 4) providestatistical and historical data regarding throughputtime for products, failure, yield rates, WIP, etc.Traffic AdvisoryInformation given to the pilot pertaining to theposition of another aircraft in the immediatevicinity. The information contains no suggestedmaneuvers. (Traffic advisory airspace is 1200 feetabove and below the aircraft and approximately45 seconds distant with respect to closure speedof the aircraft.) [TCAS]Traffic DensityThe number of transponder-equipped aircraftwithin R nautical miles (nmi) of own aircraft,divided by x (R nmi) 2. Transponder-equippedaircraft include Mode S and ATC RBS Mode Aand Mode C, and excludes own aircraft. (TCAS)TRANSTransitionTransceiverA receiver and transmitter combined in a singleunit. Same as RT.TransponderAvionics equipment that returns an identifyingcoded signal.TRBTurbulence (TURB): A weather radar warning ofapproaching turbulence.TRDTransit Routing DomainTRKTrack: The course the aircraft is traveling alongthe ground with respect to true North.TROOPTracking and Resolution Of Obsolete PartsTRFMode S TransponderTRR(1 ) Test Readiness Review(2 ) Test Rejection and RepairTRSBTime Reference Scanning Beam. Theinternational standard for MLS installations.TRU(1 ) Transformer Rectifier Unit(2 ) TrueTrue AirspeedThe true velocity of the aircraft through thesurrounding air mass.True AltitudeThe exact distance above mean sea level(corrected for temperature).True BearingThe bearing of a ground station with respect totrue north.True NorthThe direction of the north pole from the observer.TS(1 ) Time Source(2 ) Transport Service(3 ) Traffic SynchronizationTSA(1 ) Tail Strike Assembly(2 ) Technical Service AgreementTSAPTransport Service Access PointTSCTerm Service CommitmentTSDIUTransport Service Data UnitTSETotal System ErrorTSIPTrimble Standard Interface ProtocolTSMAutothrottle Servo Mount (without Clutch)TSP(1 ) Transmitted Signal Power(2) Twisted Shielded PairTSOTechnical Standard Order. Every unit built with aTSO name plate must meet TSO requirements.TSO operating temperature extremes are not thesame as the manufacturing bum-in limits.TSSTechnology Support and ServicesTSTMTime Source Transition ModuleTT(1 ) Test Tools(2 ) Total TemperatureTTTotal Inlet Temperature (Engine)TTFFTime To First FixTTGTime To Go: The time from present position tothe next navigation fix based on current aircraftground speed.TTLTransistor-Transistor LogicTTRTCAS II Receiver/TransmitterTTSTime To Station, an indication that displays theamount of time for an aircraft to reach a selectedDME ground station while traveling at a constantspeed.TTYTele typewriterTUSmart Tapping UnitTUATest Unit AdaptersTURBTurbulenceTurbulenceThe U.S. National Weather Service defines lightturbulence as areas where wind velocity shiftsare 0 to 19 feet per second (0 to 5.79 metersper second) and moderate turbulence as windvelocity shifts of 19 to 35 feet per second (5.79 to10.67 meters per second).TVBCTurbine Vane and Blade CoolingTVCTurbine Vane CoolingTVETotal Vertical ErrorTVECTest VectorTWDL(1 ) Terminal Weather Data Link(2 ) Two Way Data LinkTWDRTerminal Doppler Weather RadarTWIPTerminal Weather Information for PilotsTWNDTailwindTWPTechnical Work ProgramTWRTurbulence Weather RadarTWTTraveling Wave TubeTXTransmit (see XMIT): An annunciation that maybe displayed on the Communications RadioController (CTL, CDU, RTU) while a radio signalis being transmitted.UA(1 ) Unnumbered Acknowledgment(2 ) User ApplicationUARTUniversal Asynchronous Receiver/TransmitterUASCUniversal Avionics Systems Corp.UATUniversal Access TransceiverUAVUnmanned Air VehicleUplinkUBUtility BusUBIUplink Block IdentifierUCIUser Computer InterfaceUCSUniform Chromaticity ScaleUDUser Data. The N-User data may also betransferred between peer network members (OSIModel) as required.UDPUser Datagram ProtocolUFDRUniversal Flight Data RecorderUHFUltra-High Frequency. The portion of the radiospectrum from 300 MHz to 3 GHz.UIUnnumbered InformationUIRUpper flight Information RegionULUplinkULBUnderwater Locator BeaconULDUnit Load DeviceUMIUser-Modifiable InformationUMLUnified Modeling LanguageUMSUser-Modifiable SoftwareUMSDTUser-Modifiable Software Development ToolUMTUniversal MountUnpairedChannelA DME channel without a corresponding VOR orILS frequency.The radio transmission path upward from theearth to the aircraft.UPUniversal PlatformUPRUser Preferred RouteUPRMUniversal Platform Resource ManagementUPSMSUPS Management SystemUPSUninterruptible Power SupplyUSAFUnited States Air ForceUSBUpper Sideband is the information-carrying bandand is the frequency produced by adding thecarrier frequency and the modulating frequency.USTBUnstabilizedUTCUniversal Time Coordinated (French)UTEUniversal Trigger EngineUTPUnshielded Twisted PairUUTUnit Under TestuvUpper Sideband VoiceuwUnique WordV(1 ) Velocity(2 ) VoltV ()Critical engine failure velocity. A pilot selectablespeed on the PFD.V (R )Takeoff rotation speed. A pilot selectable speedon the PFD.V( )Takeoff safety speed. A pilot selectable speed onthe PFD.V (T )A general target speed for flight. A pilot selectablespeed on the PFD.VAVblt-AmperesVACVolts Alternating CurrentVAP(1 ) Value Added Processor(2 ) Visual Aids PanelVAPS(1 ) Virtual Applications Prototyping System(2 ) Virtual Avionics Prototyping SystemVAR(1 ) Variation(2 ) Visual-Aural Radio Range(3 ) Volt-Amps ReactiveVASIVisual Approach Slope IndicatorVAUVoltage Averaging UnitVBARPFD Flight Director Symbology for which thecommand bars move vertically for pitch commandand rotate for roll command.VBVVariable Bypass ValveVC(1 ) Design Cruising Speed(2 ) Virtual CircuitVCBVirtual Circuit BridgeVCD(1 ) Variable Capacitance Diode(2 ) Voltage Controlled DeviceVCMAXActive Maximum Control SpeedVCMINActive Minimum Control SpeedVCOVariable Controlled OscillatorVCUVDL Control UnitVD(1 ) Design Diving Speed(2 ) Heading to a DME DistanceVDCVolts Direct CurrentVDLVHF Data LinkVDLMxVHF Data Link Mode XVDRVHF Digital RadioVERVersionVESVideo Entertainment SystemVertical SpeedThe rate of change of pressure altitude, usuallycalibrated in hundreds of feet per minute.VFDesign Flap SpeedVFEFlaps Extended Placard SpeedVFOVariable Frequency OscillatorVFOPVisual Flight Rules Operations PanelVFRVisual Flight RulesVFXR (R)Flap Retraction SpeedVFXR (X)Flap Extension SpeedVG/DGVertical Gyro/Directional GyroVG orVGNDGround VelocityVGAVideo Graphics AdapterVHMaximum Level-flight Speed with ContinuousPowerVHDLVery High-speed integrated circuit HardwareDescription LanguagesVHFVery High Frequency. The portion of the radiospectrum from 30 to 300 MHz.VHSVery High SpeedVHSIC-Very High Speed Integrated Circuits-Phase 2VIHeading to a course interceptVIRVOR/ILS ReceiverVisLowest Selectable AirspeedVISVideo Intelligence SystemVIGVVariable Integral Guide VaneVISTAVirtual Integrated Software Testbed for AvionicsVIUVideo Interface UnitV/LVOR/LocalizerVLELanding Gear Extended Placard AirspeedVLFVery Low FrequencyVLOMaximum Landing Gear of Operating SpeedVLOFLift-off SpeedVLSIVery Large Scale IntegrationVLVValveVMHeading to a manual terminationV/MVoltmeterVMAXBasic Clean Aircraft Maximum CASVMC(1 ) Visual Meteorological Conditions(2 ) Minimum Control Speed with Critical EngineOutVME(1 ) Versa Module Eurocard Bus(2 ) VHF Management Entity, VME busVMECCVersa Module Eurocard Card CageVMINBasic Clean Aircraft Minimum CASVM (LO)Minimum Maneuver SpeedVMCVisual Meteorological ConditionsVmoThe maximum airspeed at which an aircraft iscertified to operate. This can be a fixed numberor a function of configuration (gear, flaps, etc.), oraltitude, or both.VMO/MMOVelocity, Maximum Operating/Mach, MaximumOperationVMONVNMS Health MonitoringVMOSVirtual Machine Operating SystemV/NAVVertical Navigation: (Also VNV). A system bywhich the crew can define a vertical path in spaceand the system can output guidance to maintainthat path.VNENever-Exceed SpeedVNOMaximum Structural Cruising SpeedVNRVHF Navigation ReceiverVNVVertical NavigationVOCRADVoice RadioVODVideo On DemandVoIPVoice Over Internet ProtocolVbispondACALSE L function that would automaticallyidentify an aircraft by a voice recording. Voispondis not yet implemented.VOMVolt-Ohm-MillimeterVORVHF Omnidirectional Radio Range. A system thatprovides bearing information to an aircraft.VOR/DMEA system in which a VOR and DME station areco-located.VOR/MBVOR/Marker BeaconVORTACA system in which a VOR and a TACAN stationare co-located.VOSVelocity Of SoundVOXVoice TransmissionVPATHVertical PathVPN(1 ) Vendor Part Number(2 ) Virtual Private NetworksVR(1 ) Takeoff Rotation Velocity(2 ) Heading to a radialVRAMVideo Random Access MemoryVREFReference VelocityVRGVDL Reference GuideVRUVideo Reproducer Unitv/sVertical SpeedVsStall VelocityVSpeedsAutomatic look-up and display of takeoff,approach, landing and missed-approach speeds.VswStall Warn VelocityVSATVery Small Aperture TerminalVSCFVariable Speed Constant FrequencyVSCS(1 ) Vertical Stabilizer Control System used onNOTAR helicopter(2) Voice Switching and Control SystemVSD(1 ) VDL Specific DTE Address(2) Vertical Situation DisplayVSI(1 ) Vertical Speed Indicator(2) Stalling Speed in a Specified FlightConfigurationVSL AdvisoryVertical Speed Limit Advisory may be preventiveor corrective (TCAS)VSMVertical Separation MinimumVSOStalling Speed in the Landing ConfigurationVSTOLVertical or Short Takeoff and LandingVSVVariable Station VaneVSWRVoltage-Standing Wave Ratio. The ratio of theamplitude of the voltage (or electric field) at avoltage maximum to that of an adjacent voltageminimum. VSWR is a measurement of themismatch between the load and the transmissionline.VTKVertical Track DistanceVTOVolumetric Top-OffVTOLVertical Takeoff and LandingVTRVariable Takeoff RatingV/TRKVertical TrackVUUtility SpeedvxSpeed for Best Angle of ClimbVYSpeed for Best Rate of ClimbW(1 ) Watt(2 ) WestWAASWide Area Augmentation System (Method ofDifferential GPS)WADWide Area DifferentialWADGNSSWide Area Differential Global Navigation SatelliteSystemWAFSWorld Area Forecast SystemWAIWing Anti-IceWANWide Area NetworkWARC-9World Administrative Radio Conference (1992)WARC-MOBWorld Administrative Radio Conference fbr theMobile ServiceWATWeight and TemperatureWATRSWest Atlantic Route StructureWaypointAposition along a route of flight. Navigationaid, airport, or geographic point a pilot uses tonavigate the aircraft.WBCWeight and Balance ComputerWBSWork Breakdown StructureWCPWXR Control PanelsWDWind DirectionWESWarning Electronic SystemWEUWarning Electronic UnitWFAWXR Flat Plate AntennaWGSWorld Geodetic SystemWGS-World Geodetic Survey of 1972WGS- 4World Geodetic System 1984Whisper ShoutA sequence of ATCRBS interrogations andsuppressions of varying power levels transmittedby TCAS equipment to reduce severity ofsynchronous interference and multipathproblems.WING CHORDAn imaginary line joining the leading and trailingedges of the wing.WINDMGWind MagnitudeWINDRWind DirectionWIPWork In ProgressWLANWireless Local Area NetworkWLDWelded Pipe and TubeWLMWireless LAN ManagerWMAWXR Antenna Pedestal and WXR WaveguideAdapterWM1WXR Indicator MountWMOWorld Meteorological OrganizationW/MODWith Modification of Vertical ProfileWMSWide-area Master StationWMSCWeather Message Switching CenterWMSCRWeather Message Switching Center ReplacementWMTWXR MountWNWeek NumberWORDGrouping of bits. Size of group varies frommicroprocessor to microprocessor.WOWWeight On WheelsWPWorking PaperWPTWaypoint. A defined geographic point used as areference for navigation.WPRWaypoint Position ReportWRAUWeather Radar Attention UnitWRSWide-area Reference StationWRTWXR Receiver/TransmitterWSDDMWeather Support for Deicing Decision MakingW/STEPWith Step Change in AltitudeWTWeightWXWeatherWXIWXR IndicatorWXPWeather Radar PanelWXRWeather Radar SystemWWWWorld Wide WebWYPTWaypoint AltitudeXAARINCX-BANDThe frequency range between 8000 and12500 MHzXBInternational Air Transport Association (IATA)X-ChannelA DME channel. There are 126 X-channels forDME operation. For the first 63 channels, theground-to-air frequency is 63 MHz be low theair-to-ground frequency. For the second 63-XChannels the ground-to-air frequency is 63 MHzabove the air-to-ground frequency.XCVRTransceiverXFRTransferXIDExchange IdentificationXLSCross-sideXLTRTranslatorXMExternal MasterXMITTransmitXMLextended Markup LanguageXMTR/RCVRT ran smitter/ReceiverXPDATC Transponder (also XPDR, X PNDR, TPR)XPDRTransponderXPTRCross Pointer: The flight director command bars.Pitch command is shown with vertical motion ofthe horizontal bar and roll command is shownwith lateral motion on the vertical bar.xsSITAXSIDECross-sideXTIX/Open Transport InterfaceXTKCrosstrack (crosstrack error)XTPExpress Transfer ProtocolYagi AntennaAn antenna with its maximum radiation parallelto the long axis of its array, consisting of a drivendipole, a parasitic dipole reflector, and oneparasitic dipole director or more.YAWRefers to movement about the vertical axis of theaircraftYSASYaw Stability Augmentation SystemYDYaw DamperZ(1 ) Refer to reflectivity factor(2 ) Zulu (GM Time)ZDEZone Distribution EquipmentZFWZero Fuel WeightZ-MarkerA marker beacon, sometimes referred to as astation locator, that provides positive identificationto the pilot when the aircraft is passing directlyover a low-frequency navigation aid.ZZulu Time。