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Welcome to the master pilot acronym list. This list includes acronyms, abbreviations, and contractions for aviation use. This list also includes acronyms for notices to air missions (NOTAM), FAA, and Controller terms. If we missed one let us know!!
S                                                  
S South or Southern latitude
S/A Semiannual
S/MTD STOL and Maneuvering Technology Demonstrator
S/N RATIO Signal-to-Noise Ratio
S/RC Send/Receive Center
S/S Sector Suite
SA Duststorm, sandstorm, rising dust or sand
SA Record Observation (weather reports only)
SA Sandstorm or Dusting
SA Surface Aviation Weather Report
SA Surveillance Approach
SA System Administrator
SAA Special Activity Airspace
SAA Systems Application Architecture
SAAAR Special Aircraft and Aircrew Authorization Required
SAAR Special Aircraft and Aircrew Requirements
SABH Simultaneous Automatic Broadcast Homer
SAC Strategic Air Command
SADT Same Direction Traffic
SAE Society of Automotive Engineers
SAE Specialty Aircraft Examiner
SAFI Semi Automatic Flight Inspection
SAGA System Safety Approach for General Aviation
SAI Safety Attribute Inspection
SAI Standby Attitude Indicator
SALR Saturated Adiabatic Lapse Rate
SALS Short Approach Lighting System
SALS Simple Approach Lighting System
SALSF Short Approach Lighting System with Sequenced Flashing Lights
SAM Stabilizer Aileron Module
SAM Surface-to Air Missile
SAMS Special Use Airspace Management System
SAN Sanitary
SAN Storage Area Network
SAO Surface Aviation Observation
SAOS Surface Observations
SAP Soon As Possible
SAPD Speed At Pilots Discretion
SAPS Staffing and Personnel System
SAR Search and Rescue
SAR Synthetic Aperture Radar
SAR Special Air Report
SARB Search and Rescue Beacon
SARH Semi-Active Radar Homing
SARP Standards and Recommended Practices
SARPS Standards and Recommended Practices
SAS Safety Assurance System
SAS Stability Augmentation System
SAS Synthetic Aperture Sonar
SASK Saskatchewan
SASO System Approach for Safety Oversight
SAT Security, Awareness, and Training System
SAT SEOAT Analytical Team
SATCOM Satellite Communications
SATFY Satisfy or Satisfactory
SATNAV Satellite Navigation
SATR So As To Reach
SAVASI Simplified Abbreviated Visual Approach Slope Indicator
SAVES Strategic Sourcing for the Acquisition of Various Equipment and Supplies
SAWRS Supplemental Aviation Weather Reporting Service
SAWRS Supplementary Aviation Weather Reporting Station
SAWRS Supplementary Aviation Weather Reporting System
SAYTA Say Time Able
SB Service Bulletin
SB Southbound
SBAS Satellite-Based Augmentation System
SBFC Standby for Further Clearance
SBGP State Block Grant Program
SBIR Small Business Innovation Research
SBND Southbound
SBS Silicon Bilateral Switch
SBS Surveillance Broadcast Services
SBSD Subside
SBSDD Subsided
SBSDNC Subsidence
SBSDS Subsides
SBT Scenario Based Training
SC Single Crystal
SC Stratocumulus
SCADA Supervisory Control and Data Acquisition
SCAN Self Correcting Automatic Navigation
SCANO Automatic scanning unit out of service
SCAOK Automatic scanning unit returned to service
SCAP System Certification and Accreditation Package
SCAT Security Command of Attitude and Thrust
SCAT Security Control of Air Traffic
SCAT Staffing and Cost Analysis Tool
SCATANA Security Control of Air Traffic and Air Navigation Aids
SCC System Command Center
SCDD Supercooled drizzle droplets
SCDX Solid-State Control Differential Transmitter
SCLN Semicolon
SCM Spoiler/Speed Brake Control Module
SCND Second (in line)
SCNDRY Secondary
SCR Sillicon Controlled Rectifier
SCS Single Channel Simplex
SCSL Standing Lenticular Stratocumulus
SCT Scattered
SCT Southern California Area TRACON (Metroplex)
SCTD Scattered
SCTR Sector
SCTY Security
SCVTS Switched Compressed Video Telecommunications Service
SDB Scheduled Data Base
SDBY Standby
SDC Synchro-to-Digital Converter
SDF Simplified Direction Finding
SDF Simplified Directional Facility
SDF Software Defined Network
SDIS Switched Digital Integrated Service
SDLC Software Development Life Cycle
SDP Service Delivery Point
SDR Service Difficulty Report
SDR System Documentation Release
SDS Switched Data Service
SE Southeast
SE System Engineer
SEADRM Seadrome
SEB South Eastbound
SEC Second (time)
SEC Strategic Event Coordination
SECM Safety and Environmental Compliance Manager
SECMR Sector Manager
SECRA Secondary Radar
SECT Sector
SEL Single Event Level
SEL Space Environment Laboratory
SELCAL Selective Calling
SELF Simplified Short Approach Lighting System With Sequenced Flashing Lights
SELS Severe Local Storms
SELY South Easterly (weather reports only)
SEM Scanning Electron Microscope
SENS Sensitivity
SEOAT Systems Engineering Operational Analysis Team
SEPN Separation
SEQ Sequence
SER Service
SER Start End of Runway
SERC Software Engineering Resource Center
SERN South Eastern (weather reports only)
SES Supervisory Electronics Specialist
SESC Space Environment Service Center
SET Spacing Efficiency Tool
SET Stack Entry Time
SETA System Engineering and Technical Assistance
SEV Severe
SEWD Southeastward
SF Standard Form
SFA Single Frequency Approach
SFAR Special Federal Aviation Regulations
SFAR Special Flight Rules Area
SFAR-38 Special Federal Aviation Regulation 38
SFC Specific Fuel Consumption
SFC Surface
SFCC Slat/Flap Control Computer
SFD Service Flow Diagram
SFERICS Atmospherics
SFIE Sport Pilot Flight Instructor Examiner
SFL Sequence Flashing Lights
SFO Sector Field Office
SFO Simulated Flame Out
SFPP Stored Flight Plan Program
SFRA Special Flight Rules Area
SFSS Satellite Field Service Station
SFU Sector Field Unit
SG Snow Grains (weather reports only)
SG Specific Gravity
SG Symbol Generator
SGD Signed
SGD Solar Geophysical Data
SGFNT Significant
SGFNTLY Significantly
SGI Silicon Graphics Incorporated
SGL Signal
SGU Symbol Generator Unit
SH Showers
SHF Super High Frequency
SHFT Shift (weather reports only)
SHFTD Shifted
SHFTG Shifting
SHFTS Shifts
SHGR Hail Showers
SHGS Hail Showers (small)
SHLD Shield
SHLW Shallow
SHORAN Short Range Navigation
SHORN Short Range Navigation System
SHP Standard Holding Procedure
SHPL Ice pellet showers
SHPO State Historic Preservation Officer
SHRA Rain showers
SHRP Strategic Highway Research Program
SHRT Short
SHRTLY Shortly
SHRTWV Shortwave
SHRTWVS Shortwaves
SHSN Snow Showers
SHTDN Shutdown
SHUD Should
SHWR Shower
SHWRS Showers
SI Snow Ice event
S/I Snow Ice event
SI Straight In Approach
SI Surface Incident - Unauthorized movement in movement area of an airport
SIA Standard Instrument Approach
SIAP Standard Instrument Approach Procedure
SIC Service Initiation Charge
SIC Silicon Integrated Circuit
SID Standard Instrument Departure
SID Station Identifier
SIERNEV Sierra Nevada
SIF Selective Identification Feature
SIG Signature
SI-GATE MOS Silicon-gate Metal Oxide Silicon Semiconductor
SIGMET Significant Meteorological Advisory
SIGWX Significant Weather
SIL Single In-Line
SIM Simulated Approach
SIMMOD Airspace and Airport Simulation Model
SIMUL Simultaneous
SIP Single In-Line Package
SIP State Implementation Plan
SIR Screening Information Request
SIR Snow and Ice on Runway
SIWL Single Isolated Wheel Load
SJP Standard Jet Penetration
SK Sky Condition (PIREP only)
SKC Sky Clear
SKED Schedule
SL Sea Level
SL Sick Leave
SLAMMR Side-Looking Advanced Multimode Maritime Radar
SLAR Sideways Looking Airborne Radar
SLCT Select
SLD Solid
SLD Supercooled large droplets
SLEP Service Life Extension Program
SLGT Slight
SLGTLY Slightly
SLMM Simultaneous compass locator at middle marker
SLO Slow
SLOLY Slowly
SLOM Simultaneous compass locator at outer marker
SLOR Slower
SLP Sea Level Pressure
SLP Slope
SLP Speed Limiting Point
SLPG Sloping
SLR Slush on Runway
SLRAP Standard Low Frequency Range Approach
SLS Satellite Landing System
SLS Side Lobe Suppression
SLT Sleet
SLW Slow
SLW Supercooled liquid droplets
SLY Southerly
SM Statute Mile
SMA Surface Monitor Aid
SMA Surface Movement Advisory
SMAR Special Military Activity Routes
SMC Curface Movement Control
SMC Squawk Mode Code
SMF Systems Management Facility
SMGC Surface Movement Guidance and Control
SMGCS Surface Movement Guidance and Control System
SMI Static Memory Interface
SMK Smoke
SML Small
SMLR Smaller
SMMC System Maintenance Monitor Console
SMO System Management Office
SMPS Sector Maintenance Processor Subsystem
SMR Statute Mile Radius
SMR Surface Movement Radar
SMRY Summary
SMS Safety Management System
SMS Simulation Modeling System
SMS Surface Management System
SMS Synchronous Meteorological Satellite
SMS Systems Maintenance Sector
SMT Schedule Management Toolset
SMT Submit
SMTH Smooth
SMTHR Smoother
SMTHST Smoothest
SMTM Sometime
SMWHT Somewhat
SN Snow
SN Strategic Navigation
SN Systems Navigation
SNBNK Snowbank
SND Sand or sanded or sanding
SNFLK Snowflake
SNGL Single
SNOINCR Snow depth increase in past hour
SNOINCRG Snow increasing
SNOWTAM NOTAM Reporting the presence or removal of hazardous conditions due to snow, ice, slush or standing water associated with snow, slush or ice on the movement area
SNR Signal-to-Noise Ratio
SNSH Snow Showers
SNST Sunset
SNT Staffed NextGen Tower
SNW Snow
SNWFL Snowfall
SOAP Spectrometric Oil Analysis Program
SOAR System of Airports Reporting
SOB Souls On Board
SOC Service Operations Center
SOC Service Oversight Center
SOC System Operations Control
SOCC NORAD Sector Operations Control Center
SODA Statement of Demonstrated Ability
SOE Supervised Operating Experience
SOIA Simultaneous Offset Instrument Approaches
SOIR Simultaneous Operations On Intersecting Runways
SOIWR Simultaneous Operations on Intersecting Wet Runways
SOL Solenoid
SOM Satellite communication
SOM Start Of Message
SOMSG See Our Message
SOP Standard Operating Practice
SOP Standard Operating Procedure
SORAP Standard Omni Range Approach
SOS Silicon-on-Sapphire
SOT Start Of Transmission
SOW Statement of Work
SP Standard Holding Pattern
SP Station Pressure
SP Surveillance Processing
SPAN Stored Program for Alpha Numerics
SPAS System Performance Analysis System
SPB Seaplane Base
SPCLY Especially
SPD Speed
SPDS Speeds
SPE Sport Pilot Examiner
SPEC Specification
SPECI Aviation selected special weather report
SPENES Satellite precipitation estimate statement
SPF Super Plastic Forming
SPIFR Single Pilot IFR
SPKL Sprinkle
SPKLS Sprinkles
SPKR Speaker
SPL Special
SPL Supplementary flight plan
SPLNS South Plains
SPO Strategic Plan of Operation
SPOT Special Purpose Operational Training
SPOT Spot wind
SPR Software Problem Report
SPRD Spread
SPRDG Spreading
SPRDS Spreads
SPRL Spiral
SPS Standard Positioning Service
SPT Strategic Planning Team
SQ Squall
SQAL Squall
SQDN Squadron
SQK Squawk
SQL Squelch
SQLN Squall Line
SR Standard Range Approach
SR Status Register
SR Sunrise
SRA Surveillance Radar Approach
SRAP Sensor Receiver and Processor
SRB Solid Rocket Booster
SRCH Search
SRD Shift Register Decoder
SRE Surveillance radar element of precision approach radar system
SRG Short Range
SRM Safety Risk Management
SRM Single Pilot Resource Management
SRMD Safety Risk Management Document
SRMDM Safety Risk Management Memo
SRN Southern
SRND Surround
SRNDD Surrounded
SRNDG Surrounding
SRNDS Surrounds
SRP Selected Reference Point
SRPN Special Requisition Priority Number
SRR Search and Rescue Region
SRS Shuttle Reservation System
SRT Shift Register Transistor
SRTM Shuttle Radar Topography Mission
SRY Secondary
SS Sandstorm
SS Slow Slew
SS Sunset
SSALF Simplified Short Approach Lighting System with Sequenced Flashers
SSALR  Simplified Short Approach Lighting System with Runway Alignment Indicator Lights
SSALS  Simplified Short Approach Lighting System
SSB Single Side Band
SSB Supersonic Bomber
SSC System Support Center
SSCT Solid-State Control Transformer
SSD Static Sensitive Device
SSD System Support Directive
SSE Servicing Security Element
SSE South South East
SSEC Static Source Error Correction
SSELY South-southeasterly
SSERN South South Eastern (weather reports only)
SSEWD South South Eastward (weather reports only)
SSM System Support Modification
SSNO Request No SIDs or STARs
SSR Secondary Surveillance Radar
SSR Solid State Relay
SSRWG Systems Safety Risk Working Group
SST Supersonic Transport
SST System Shakedown Testing
SSTO Single-Stage To Orbit
SSV Standard Service Volume
SSW South South West
SSWLY South-southwesterly
SSWRN South South Western (weather reports only)
SSWWD South South Westward (weather reports only)
ST Saint
ST Stratus
ST Synchro Transmitter
ST&E Security Test and Evaluation
STA Straight in Approach
STAC Supersonic Transport Aircraft Committee
STADMR Station Administrator
STAGN Stagnation
STALO Stabilized Local Oscillator
STAMP Site Transition Activation Management Plan
STAR Standard Terminal Arrival Route
STARS Standard Terminal Automation Replacement System
STATE Military, customs, or police services
STBL Stable
STBLTY Stability
STBY Standby
STC Sensitivity Time Control
STC Supplemental Type Certificate
STCLB Start Climb
STCM Stabilizer Trim Control Mode
STD Standard
STDST Start Descent
STDY Steady
STEM Shaped-Tube Electrolytic Machining
STF Stratiform
STFR Stratus fractus
STFRA Stratus fractus
STFRM Stratiform
STG Strong
STGLY Strongly
STGR Stronger
STGST Strongest
STLT Satellite
STM Storm
STMGR Station Manager
STMP Special Traffic Management Program
STMS Storms
STMUX Statistical Data Multiplexer
STN Station
STNR Stationary
STNRY Stationary
STNS Stations
STOL Short Takeoff and Landing
STOVL Short Takeoff, Vertical Landing
STR Subject terminal control release
STR System Technical Release
STRO Stereo Routes
STS Status
STT Staffing to Traffic
STTL Schottky Transistor-Transistor Logic
STVS Small Tower Voice Switch
STWL Stopway Light
STWY Stopway
SUA Special Use Airspace
SUA/ISE Special Use Airspace/Inflight Service Enhancement
SUB Substitute
SUBFIX Subject to correction
SUBJ Subject to
SUBTRPCL Subtropical
SUF Sufficient
SUFLY Sufficiently
SUG Suggest
SUGG Suggesting
SUGS Suggests
SUP Supply
SUP Suspected Unapproved Parts
SUPCHG Supercharge
SUPCOM Supervisors Committee (AAT AND AAF)
SUPG Supplying
SUPPL Supplement
SUPPS Supplementary Procedures
SUPR Superior
SUPS Supplies
SUPSD Supersede
SUPSDG Superseding
SUPSDS Supersedes
SUPT Superintendent
SUPVR Supervisor
SURPIC Surface Picture
SUSP Suspend
SVC Service
SVCA Service A
SVCB Service B
SVCBL Serviceable
SVCC Service C
SVCO Service O
SVFB Interphone Service F (B)
SVFC Interphone Service F (C)
SVFD Interphone Service F (D)
SVFO Interphone Service F (A)
SVFR Special Visual Flight Rules
SVFR Special Visual Flight Rules
SVG Serving
SVN Space Vehicle Number
SVR Severe
SVRL Several
SW- Light snow shower
SW Southwest
SW Switch
SW+ Heavy snow shower
SWAP Severe Weather Avoidance Procedure/Program/Plan
SWB Scheduled Weather Broadcast
SWB South Westbound
SWD Southward
SWIFT Selections Within Faster Times
SWIM System Wide Information Management
SWLG Swelling
SWLY South Westerly (weather reports only)
SWOMCD SELS Mesoscale Discussion
SWPPP Storm Water Pollution Protection Plan
SWRN South Western (weather reports only)
SWSL Supplemental Weather Service Location
SWWD Southwestward
SWY Stopway
SX Stability Index
SXN Section
SXNS Sections
SYD Release Subject Your Discretion
SYM GEN Symbol Generator
SYNOP Synoptic
SYNS Synopsis
SYS See Your Service
SYS System
T                                                  
T Temperature
T Trace (weather reports only)
T Training
T Tropical (air mass)
T True (bearing)
T Transmit
T/C Top of Climb
T/D Top of Descent
T/R Transportation Request
T1MUX T1 Multiplexer
TA Temperature (PIREP only)
TA Total Aboard
TA Traffic Advisory
TA Transition Altitude
TAA Technically Advanced Aircraft
TAA Terminal Arrival Area
TAAS Terminal Advance Automation System
TAC Tactical Air Command (USAF) Tester
TAC Terminal Area Chart
TACAN Tactical Air Navigation
TACAN Tactical Air Navigational Aid
TACAN Tactical Aircraft Control and Navigation
TACEVAL Tactical Evaluation
TACLO Tactical Air Command Liaison Officer
TACR TACAN at VOR, TACAN only
TACR Tactical Air Navigation
TAD Tower Approach and Departure Control Facility
TADS Target Acquisition and Designation System
TAF Terminal Aerodrome Forecast
TAIL Tail Wind
TAMR Terminal Automation Modernization and Replacement
TAND Tandem
TANDA Time and Attendance Report
TANS Tactical Air Navigation System
TAO TACAN Only
TAO Time and Altitude Over
TAOARC Terminal Area Operations Aviation Rulemaking Commitee
TAP Technically Advanced Pilot
TAPER Temporary Appointment Pending Establishment of a Register
TAR Terminal Area Surveillance Radar
TARND Turn Around
TARS Terminal Automated Radar Service
TARS Tethered Aerostat Radar System
TAS True Air Speed
TASR Terminal Area Surveillance Radar
TAT Total Air Temerature
TATCA Terminal Air Traffic Control Automation
TAV Trans-Atmospheric Vehicle
TAVT Terminal Airspace Visualization Tool
TAWOG Travel Arrangements Without Government expense
TAWS Terrain Awareness and Warning System
TB Turbulence (PIREP only)
TBDP Tie Bus Differential Protection
TBFM Time Based Flow Management
TBJT Turbojet
TBO Time Between Overhauls
TBO Trajectory Based Operation
TC Time Check
TC Tropical Cyclone
TC Type Certificate
TCA Tactical Customer Advocate
TCA Terminal Control Area
TCA Traffic Control Airport or Tower Control Airport
TCACCIS Transportation Coordinator Automated Command and Control Information System
TCAP Traffic Count Automation Program
TCAS Traffic Alert and Collision Avoidance System
TCC DOT Transportation Computer Center
TCC Thrust Control Computer
TCCC Tower Control Computer Complex
TCDS Type Certificate Data Sheet
TCE Tone Control Equipment
TCE Training Center Evaluator
TCH Threshold Crossing Height
TCHD Threshold Crossing Height Downwind
TCHU Threshold Crossing Height Upwind
TCLT Tentative Calculated Landing Time
TCNS Tower Construction Notification System
TCNTL Transcontinental
TCO Telecommunications Certification Officer
TCO Training Course Outline
TCOM Terminal Communications
TCP Transfer of Control Point
TCS Touch Control Steering
TCS Tower Communications System
TCU Towering Cumulus
TCVR Transceiver
TD Touchdown
TD Transmitter Distributor
TDA Today
TDC Top Dead Center
TDDS Terminal Data Display System
TDEL Time Delay
TDLS Terminal Data Link System
TDLS Tower Data-Link Services
TDM Top Division Multiplex
TDMUX Time Division Data Multiplexer
TDO Tornado
TDOP Time Dilution of Precision
TDRS Tracking and Data Relay Satellite
TDWR Terminal Doppler Weather Radar
TDY Temporary Duty
TDZ Touchdown Zone
TDZ/CL Touchdown Zone and Runway Centerline Lighting
TDZE Touchdown Zone Elevation
TDZL Touchdown Zone Light (system)
TEB Tri-Ethyl-Borane
TEC Tower En route Control
TECA Tower En route Control Area
TECR Technical Reason
TEL Telecommunications
TEL Telephone
TELAU Teleautograph
TELCO Telephone Company
TELCON Telephone Conference
TELEX Telephone Exchange
TELMS Telecommunications Management System
TELRY Telegraph Reply
TEMAC Trailing Edge of Mean Aerodynamic Chord
TEMP Temperature
TEMPO Temporary
TEND Trend
TERCOM Terrain-Commanded
TEREC Tactical Electronic Reconnaissance
TERP Terminal Instrument Procedure
TERPS Terminal Instrument Procedures
TET Tetrahedron
TET Turbine Entry Temperature
TF Terrain Following
TF Track to Fix
TFAC To Facility
TFC Traffic
TFDM Tower Flight Data Manager
TFHC Thin-Film Hybrid Circuit
TFM Traffic Flow Management
TFMS Traffic Flow Management System
TFR Temporary Flight Restriction
TFR Terrain-Following Radar
TFR Transfer
TFRCD Traffic Received
TFT Thin-Film Transistor
TFX Tactical Fighter Experimental
TFZ Traffic Zone
TGL Touch and Go Landing
TGS Taxiing Guidance System
TGT Turbine Gas Temperature
TH Threshold
THB Through-Hole Board
THD Thunderhead
THDR Thunder
THK Thick
THKNG Thickening
THKNS Thickness
THKR Thicker
THKST Thickest
THLD Threshold
THN Thin
THNG Thinning
THNR Thinner
THNST Thinnest
THP Thrust Horsepower
THR Threshold
THRFTR Thereafter
THRU Through
THRUT Throughout
THSD Thousand
THTN Threaten
THTND Threatened
THTNG Threatening
THTNS Threatens
TI Texas Instruments
TIAS True Indicated Airspeed
TIB Technical Instruction Book
TIBA Traffic Information Broadcast by Aircraft
TIBS Telephone Information Briefing Service
TIG Tungsten Inert Gas
TIL Until
TIMS Telecommunications Information Management System
TINOP Transponder Inoperative
TIP Until Past
TIPH Taxi Into Position and Hold
TIPS Terminal Information Processing System
TIS Traffic Information Service
TIS-B Traffic Information Service-Broadcast
TIT Turbine Inlet Temperature
TKE Track Angle Error
TKOF Takeoff
TL Taxilane
TLM Telemetry
TLRNC Tolerance
TLTP Too Long To Print
TLWD Tailwind
TM Time (PIREP only)
TM Traffic Management
TM&O Telecommunications Management and Operations
TMA Terminal Control Area
TMA Terminal Maneuvering Area
TMA Traffic Management Advisor
TMC Thrust Management Computer
TMC Traffic Management Coordinator
TMC Travel Management Center
TMC/MC Traffic Management Coordinator/Military Coordinator
TMCC Terminal Information Processing System
TMCC Traffic Management Computer Complex
TMF Traffic Management Facility
TMI Traffic Management Initiative
TML Television Microwave Link
TMLI Television Microwave Link Indicator
TMLR Television Microwave Link Repeater
TMLT Television Microwave Link Terminal
TMP Traffic Management Processor
TMPA Traffic Management Program Alert
TMPRY Temporary
TMPRYLY Temporarily
TMS Thrust Management System
TMS Traffic Management System
TMSP Thrust Mode Select Panel
TMSPS Traffic Management Specialists
TMT Transmit
TMU Traffic Management Unit
TMW Tomorrow
TNA Turn Altitude
TNAV Terminal Navigational Aids
TNDCY Tendency
TNDCYS Tendencies
TNGT Tonight
TNH Turn Height
TNT Turbulence In and Near Thunderstorms
TNTV Tentative
TNTVLY Tentatively
TO Technical Order
TO Travel Order
TOC To Be Continued
TOC Top of Climb
TOCC Technical Operations Control Center
TOD Time of Delivery
TOD Top of Descent
TODA Takeoff Distance Available
TOF Time Of Flight
TOFMS Time of Flight Mass Spectrometer
TOG Takeoff Gross weight
TOGA Takeoff Go Around
TOP Cloud Top
TOPPS Turbine Overhaul Power Plant Support
TOPS Telecommunications Ordering and Pricing System (GSA software tool)
TOR Time Of Receipt
TOR Traffic On Request
TORA Takeoff Run Available
TOT Time Of Transmission
TOVC Top of Overcast
TOW Tube-launched Optically-tracked Wire-guided
TP Telecommunication Processor
TP Track Processing
TP Turning Point
TP Type Aircraft (PIREP only)
TPA Traffic Pattern Altitude
TPE Technical Personnel Examiner
TPG Topping
TPP Terminal Procedures Publication
TPR Technical Performance Record
TR Telecommunications Request
TR Track
T-R Transformer-Rectifier
TR VFR Low Altitude Training Routes
TRA Temporary Reserved Airspace
TRACAB Terminal Radar Approach Control in Tower Cab
TRACON Terminal Radar Approach Control
TRACON Terminal Radar Approach Control Facility
TRAD Terminal Radar
TRAD Terminal Radar Service
TRAN Transient
TRANS Transmit or Transmitter
TRB Transportation Research Board
TRBL Trouble
TRCV Tricolor Visual Approach Slope Indicator
TRD Technical Reference Data
TRDR Technical Reference Data Record
TRG Training
TRIB Tributary
TRK Track
TRKG Tracking
TRL Transistor-Resistor Logic
TRLVL Transition Level
TRML Terminal
TRMT Terminate
TRMTD Terminated
TRMTG Terminating
TRMTS Terminates
TRNG Training
TRNSP Transport
TRNSPG Transporting
TROF Trough
TROFS Troughs
TROP Tropopause
TRP Thrust Rating Panel
TRPCD Tropical Continental (air mass)
TRPCL Tropical
TRPLYR Trapping Layer
TRRN Terrain
TRSA Terminal Radar Service Area
TRSN Transition
TRTD Treated
TRU Transformer-Rectifier Unit
TRW Thunderstorm
TRW+ Thunderstorm with heavy rain shower
TS Team Supervisor
TS Thunderstorm
TS Top Secret
TS+ Thunderstorm with heavy snow
TSA Taxiway Safety Area
TSA Transportation Security Administration
TSARTS Terminal Stand-Alone Radar Training System
TSATLC Transatlantic
TSC Technical Support Center
TSD Traffic Situation Display
TSE Total Navigation System Error
TSEC Terminal Secondary Radar Beacon
TSEC Terminal Secondary Radar Service
TSFR Transfer
TSFRD Transferred
TSFRG Transferring
TSFRS Transfers
TSGR Thunderstorm with hail
TSGS Thunderstorm with small hail
TSHWR Thundershower
TSHWRS Thundershowers
TSMNO Transmitting capability out of service
TSMOK Transmitting capability returned to service
TSNO Thunderstorm Information Not available
TSNT Transient
TSO Technical Standard Order
TSP Telecommunications Service Priority
TSPAC Transpacific
TSPL Thunderstorm with Ice Pellets
TSQLS Thundersqualls
TSR Telecommunications Service Request
TSRA Thunderstorm with Rain
TSS Tower Simulation System
TSSA Thunderstorm with Duststorm or Sandstorm
TSSAM Tri-Service Standoff Attack Missile
TSSC Technical Support Services Contract
TSSN Thunderstorm with Snow
TSTM Thunderstorm
TSTM Thunderstorm
TSTMS Thunderstorms
TSTO Two Stage-to-Orbit
TSU Telescopic Sighting Unit
TSW Thunderstorm with snow showers
TSW+ Thunderstorm with heavy snow showers
TSYS Terminal Equipment Systems
TT Teletypewriter
TT Total Temperature
TTG Time To Go
TTH Tactical Transport Helicopter
TTL Transistor-Transistor Logic
TTL Tuned To Localizer
TTMA TRACON Traffic Management Advisor
TTS Teletype Switching Facilities
TTS Time To Station
TTWG Technical Transfer Working Group
TTY Teletype
TTY Teletypewriter station
TUR Time Utilization Report
TURB Turbulence
TURBC Turbulence
TURBT Turbulent
TVASIS T Visual Approach Slope Indicator System
TVCS Thrust Vectoring Control System
TVL Travel
TVOR Terminal VHF Omnidirectional Range
TVOR Terminal VOR
TVSR Terminal Voice Switch Replacement
TW Taxiway
TWA Trans World Airlines
TWD Toward
TWDS Towards
TWEB Transcribed Weather Broadcast
TWI Twilight
TWIP Terminal Weather Information for Pilots
TWR Aerodrome control tower
TWR Tower
TWR Tower (non-controlled)
TWR Turbulence-detecting Weather Radar
TWRG Towering
TWS Radar Track While Scan
TWT Traveling Wave Tube
TWU Tactical Weapons Unit
TWX Teletypewriter exchange service
TWY Taxiway
TWYL Taxiway Link
TX Transmitter
TXG Taxiing
TXL Taxilane
TXPDR Transponder
TXT Text
TY Type (FAACIS)
TYP Type (aircraft)
TYPH Typhoon
TYPNO Teletypewriter communications out of service
TYPOK Teletypewriter communications returned to service
U                                                  
U Intensity Unknown (weather reports only)
U/S Unserviceable
UA Routine Pilot Report (PIREP)
UA Unable to Approve arrival for the time specified
UAB Until Advised By
UAC Upper Area Control Center
UAG Upper Atmosphere Geophysics
UAR Upper Air Route
UART Universal Asynchronous Receiver-Transmitter
UAS Uniform Accounting System
UAS Unmanned Aircraft Systems
UAT Universal Access Transceiver
UAT Until Advised by the Tower
UAV Unmanned Aerial Vehicle
UBA User Benefits Applications
UBI User Benefits Infrastructure
UBR Utility Bus Relay
UC Under Construction
UCDWN Until Cleared Down
UCLT Until Cleared to Land by the Tower
UCR Unsatisfactory Condition Report
UD Unable to approve departure for the time specified
UDDF Up and Down Drafts
UDF Ultra High Frequency Direction Finding station
UDF Unducted Fan
UERE User Equivalent Range Error
UF Under Frequency
UFA Until Further Advised
UFAS Uniform Federal Accessibility Standard
UFET Unipolar Field Effect Transistor
UFH Ultra High Frequency
UFN Until Further Notice
UFO Unidentified Flying Object
UHA Unable Higher Altitude
UHDODT Unable Higher Due Opposite Direction Traffic
UHDSDT Unable Higher Due Same Direction Traffic
UHDT Unable Higher Due Traffic
UHF Ultra High Frequency
UIC Upper Information Center
UIR Upper Flight Information Region
UJT Unijunction Transistor
UK United Kingdo
ULDT Unable Lower Due Traffic
ULR Ultra Long Range
UM Unable to Maintain
UN Unable
UN United Nations
UNA Unable
UNAP Unable to Approve
UNAPV Unable to Approve
UNAR Unable to Approve Altitude Requested
UNATNDD Unattended
UNAVBL Unavailable
UNCC Unable to Contact Company radio
UNDLD Undelivered
UNEC Unnecessary
UNHRD Unheard
UNICOM Universal Communications
UNID Unidentified
UNIX Uniplexed Information and Computing System
UNKN Unknown
UNL Unlimited
UNLGTD Unlighted
UNMON Unable to Monitor
UNMON Unmonitored
UNOFFL Unofficial
UNRDBL Unreadable
UNREL Unreliable
UNRELBL Unreliable
UNRR Unable to approve Route Requested
UNRSTD Unrestricted
UNSATFY Unsatisfactory
UNSBL Unseasonable
UNSKED Unscheduled
UNSTBL Unstable
UNSTDY Unsteady
UNSTL Unsettle
UNSTLD Unsettled
UNTC Unable to establish Contact
UNUSBL Unusable
UP Unknown Precipitation
UPDFTS Up Drafts
UPDT Update
UPR Upper
UPR User Preferred Route
UPS Uninterruptable Power Supply
UPSLP Upslope
UPSTRM Upstream
UPT User Preferred Trajectory
UQOT Unquote
URA Uniform Relocation Assistance and Real Property Acquisition Policies Act of 1970
URAUZ You Are Authorized
URET User Request Evaluation Tool
URG Urgent
URIZR your Recommendation is Requested
USA U.S. Army
USAF U.S. Air Force
USAF United States Air Force
USAFIB U.S. Army Aviation Flight Information
USBL Usable
USC United States Code
USCG U.S. Coast Guard
USCG United States Coast Guard
USG United States Government
USMC U.S. Marine Corps
USN U.S. Navy
USNO United States Naval Observatory
USNOF United States NOTAM Office
USNS United States NOTAM System
USNS United States Notices to Airmen System
USOAP Universal Safety Oversight Audit Program
USOC Uniform Service Order Code
USP Urgent Special Observation (weather reports only)
USUA United States Ultralight Association
UTA Upper control Area
UTC Coordinated Universal Time (ZULU)
UTCOK Coordinated Universal Time Coordinate Check Completed
UTL Unable to Locate
UUA Urgent Pilot Report (PIREP)
UV Under Voltage
UVV Upward Vertical Velocity
UVVS Upward vertical velocities
UW Upwind
UWNDS Upper Winds
V                                                  
V Variable (weather reports only)
V Voltage
V/PD Vehicle/Pedestrian Deviation
V1 Takeoff Decision Speed
V2 MIN Minimum Takeoff Safety Speed
V2 Takeoff Safety Speed
VA Aolcanic ash
VA Design Maneuvering Speed
VA Victor Airways
VA Volt-Amps
VAC Visual Approach Chart
VAC Volts Alternating Current
VACAPES Virginia Capes
VADA VFR Arrival delay advisory
VAE Vintage Aircraft Examiner
VAFTAD Volcanic Ash Forecast Transport and Dispersion
VAL In Valleys (Weather)
VALE Voluntary Airport Low Emission
VALE Voluntary Airport Low Emission Program
VAN Runway Control Van
VAPI Visual Approach Path Indicator
VAPS V/STOL Approach System
VAR Magnetic Variation
VAR Visual Aural Radio Range
VAR Volt-Amps Reactive
VARN Variation
VAS Visual Augmentaiton System
VASI Visual Approach Slope Indicator
VASIS Visual Approach Slope Indicator System
VB Design Speed for Maximum Gust Intensity
VBS Vertical Beam Sensor
VBSCRIPT Visual Basic Scripting Edition
VC Design Cruise Speed
VC Variable Cycle
VC Vicinity
VCFG Fog in Vicinity
VCNTY Vicinity
VCO Voltage-Controlled Oscillator
VCOA Visual Climb Over Airport
VCOT VFR Conditions on top
VCTR Vector
VD Design diving speed
VDA Vertical Descent Angle
VDC Volts Direct Current
VDF Very High Frequency Direction-Finding Station
VDF/MDF Demonstrated Flight Diving Speed
VDL Very High Frequency Data Link
VDME VOR with Distance Measuring Equipment
VDOP Vertical Dilution of Precision
VDP Visual Descent Point
VDR Voltage Dependent Resistor
VDU Visual Display Unjt
VDUC VAS Data Utilization Center (NSSFC)
VEARS VSCS Emergency Access Radio System
VER Vertical
VF Design Flap Speed
VF Maintaining visual flight (Special VFR)
VF Voice Frequency
VFC Voltage-to-Frequency Converter
VFC/MFC Maximum speed for stability characteristics
VFE Maximum Flap-extended speed
VFEE Vintage Flight Engineer Examiner
VFLT Visual flight
VFPR Via flight planned route
VFR Visual Flight Rules
VFRSA VFR restrictions still apply
VFTO Final Takeoff Speed
VFY Verify
VFYD Verified
VFYG Verifying
VFYS Verifies
VG Variable Geometry
VGSI Visual Guidance Slope Indicator
VGU Vertical Gyro Unit
VH Maximum level flight speed with continuous power
VHF Very High Frequency
VHIC Very High Speed Integrated Circuit
VIA By way of
VIFF Vectoring in Forward Flight
VIGV Variable Inlet Guide Vanes
VIP Very Important Person
VIP Visual Integrated Presentation
VIS Visibility
VLCT Very Large Commercial Transport
VLCTY Velocity
VLCTYS Velocities
VLE Maximum landing gear extended speed
VLF Very Low Frequency
VLFD Via low frequency direct
VLJ Very Light Jet
VLNT Violent
VLNTLY Violently
VLO Maximum landing gear operating speed
VLOF Lift-off speed
VLR Very long range
VLY Valley
VLYS Valleys
VM Voice modulation
VMC Minimum control speed with critical engine inoperative
VMC Visual Meteorological Conditions
VMINI Minimum speed IFR
VMO/MMO Maximum operating limit speed
VMOS Vertical Metal Oxide Silicon Semiconductor
VMS Virtual Memory System
VMU Minimum unstick speed
VNAP Vertical Noise Abatement Procedures
VNAV Vertical Navigation
VNAV Visual Navigational Aids
VNE Never exceed speed
VNEI Never exceed speed IFR
VNO Maximum structural cruising speed
VNTSC Volpe National Transportation System Center
VOD Via Omni Direct
VOIP Voice Over Internet Protocol
VOL Volume
VOLMET Meteorological information for aircraft in flight
VOM Volt-Ohm Milliammeter
VON Virtual On-net
VOPR Voice Operated Relay
VOR APPR VOR Approach
VOR Very High Frequency Omnidirectional Range
VOR VHF Omnidirectional radio range
VOR/DME Very High Frequency Omnidirectional Range Collocated with Distance Measuring Equipment
VOR/DME VHF Omnidirectional Range/Distance Measuring Equipment
VOR/DME VOR and DME (collocated)
VOROC VOR On Course
VORT Vorticity
VORTAC Very High Frequency Omnidirectional Range Collocated Tactical Air
VORTAC VOR and TACAN (collocated)
VORTAC VOR collocated with TACAN
VOT VOR Airborne equipment test facility
VOT VOR Test Facility
VOT VOR Test signal
VOT Vorticity
VOU Voucher
VPA Vertical Path Angle
VPD Vehicle or Pedestrian Deviation - a surface incident caused by a vehicle or pedestrian
VR Rotation Speed
VR Veer
VR VFR military training routes
VR Visual Reference
VR Volts Reculated
VR Visual Route (Military)
VRA Vertical Resolution Advisory
VRB Variable
VRBL Variable
VREF Reference landing speed
VRG Visual Reference Gate
VRISL Vancouver Island, BC
VRMS Volts Root Mean Squre
VRRP Voice Recorder Replacement Program
VRS Voice Recording System
VRT MOTN Vertical motion
VRY Very
VS Stalling speed
VS Vertical speed
VS0 Stalling speed in the landing configuration
VS1 Stalling speed for a specified flight configuration
VSA By visual reference to the ground
VSA Enhanced Visual Separation on Approach
VSB Visible
VSBP Voice Switch Bypass
VSBY Visibility
VSBYDR Visibility Decreasing Rapidly
VSBYIR Visibility Increasing Rapidly
VSCS Voice Switching and Control System
VSCU Vertical Signal Conditioner Unit
VSI Vertical Speed Indicator
VSL Vessel
VSP Vertical Speed
VSPI Visual glide Path Indicator
VSR Reference stall Speed
VSR0 Reference stall speed in a landing configuration
VSR1 Reference stall speed in a specific configuration
VSTOL Vertical/Short Takeoff and Landing
VSV Variable Stator Vanes
VSW Speed at which onset of natural or artificial stall warning occurs
VSWR Voltage standing wave ratio
VT Terminal Velocity
VTA Vertex Time of Arrival
VTAC VOR collocated with TACAN
VTAS Visual Target Acquisition System
VTF Vector To Final
VTL Variable Threshold Logic
VTOL Vertical Takeoff and Landing
VTOSS Takeoff saftey speed for Category A rotocraft
VTS Voice Telecommunications System
VV Vertical Visibility (indefinite ceiling)
VVI Vertical Velocity Indicator
VX Speed for best angle of climb
VXSE Best angle of climb speed with one engine inoperative
VY Speed for best rate of climb
W                                                  
W Warm (air mass)
W Watts
W West or Western longitude
W White
W/P Waypoint
W/V Wind Vector
WA AIRMET
WAA Warm Air Advection
WAAS Wide Area Augmentation System
WAC World Aeronautical Chart
WADGPS Wide Area Differential Global Positioning System
WAFC World Area Forecast Center
WAIOP Will accept; If Offered (position)
WAN Wide Area Network
WARN Warning
WARP Weather and Radar Processor
WASS Wide Area Augmentation System - GPS
WB Westbound
WBAR Wing Bar lights
WBND Westbound
WBRBN Will be Reported by NOTAM
WBRH Weather Bureau Regional Headquarters
WBS Work Breakdown Structure
WBTS Whereabouts
WC Work Center
WCA Wind Correction Angle
WCAM Weather Camera
WCIS Workmen's Compensation Information System
WCLC Watch Check List Completed
WCMD Wind Corrected Munitions Dispenser
WCP Weather Communications Processor
WCP Weather Radar Control Panel
WD Wind Direction Angle
WDC1 World Data Centers in Western Europe
WDC2 World Data Centers throughout rest of world
WDI Wind Direction Indicator
WDLY Widely
WDSPR Widespread
WDSPRD Widespread
WEA Weather
WECO Western Electric Company
WEF With Effect From or Effective From
WESCOM Western Electric Satellite Communications
WFD Widespread Fatigue Damage
WFO Weather Forecast Office
WFOS Weather Forecast Offices
WFP Warm Front Passage
WG Working Group
WGS World Geodetic System
WGS84 World Geodetic System 1984
WI Within
WIBIS Will be Issued
WICA While In Control Area
WICZ While In Control Zone
WID Width
WIDS Weather Immediate Decision Service
WIE With Immediate Effect or Effective Immediately
WIFI Wireless Fidelity
WILCO Will Comply
WINGS FAA’s Pilot Proficiency Awards Program
WINT Winter
WINTEM Forecast upper Wind and Temperature for aviation
WIP Work In Progress
WJHTC William J. Hughes Technical Center
WK Weak
WKDAY Weekday
WKEND Weekend
WKN Weaken
WKNG Weakening
WKNS Weakens
WKR Weaker
WKST Weakest
WL Will
WLAV Will Advise
WLY Westerly
WMO World Meteorological Organization
WMS Web Map Service
WMS Wide-area Master Station
WMSC Weather Message Switching Center
WMSCR Weather Message Switching Center Replacement
WND Wind
WNDS Winds
WNDS Weather Near-Term Decision Service
WNW West North West
WNWLY West-northwesterly
WNWRN West North Western (weather reports only)
WNWWD West North Westward (weather reports only)
WO Washington Office
WO Washout
WO Without
WOCC Washington Operations Center Complex
WP Waypoint
WPDS Weather Planning Decision Service
WPLTO Western Plateau
WPM Words Per Minute
WPRT Waypoint Report
WPT Waypoint
WR Wet Runway
WRC Well to Right of Course
WRM Warm
WRMFNT Warm Front
WRMFNTL Warm Frontal
WRMG Warming
WRMR Warmer
WRMST Warmest
WRN Western
WRNG Warning
WRNGS Warnings
WRS Wide Area Augmentation System Reference Station
WRS Wide-area Reference Station
WRS Worse
WS SIGMET
WS Weak Signals
WS Wind Shear
WS Wind Speed
WSA Western Service Area
WSC Western Service Center
WSCMO Weather Service Contract Meteorological Observatory
WSFO Weather Service Forecast Office
WSFOS Weather Service Forecast Offices
WSHFT Wind Shift
WSHFTS Wind Shifts
WSO Weather Service Office
WSOM Weather Service Operations Manual
WSOS Weather Service Offices
WSP Weather System Processor (replacement for LLWAS)
WSP Weather Systems Processor
WSR Weather Surveillance Radar
WSR Wet Snow on Runway
WSSF National Weather Service Support Facility
WSSU National Weather Service Support Unit
WST Convective SIGMET
WSTCH Wash range
WSUS Windows Server Update Service
WSW West South West
WSWLY West-southwesterly
WSWRN West South Western (weather reports only)
WSWWD West South Westward (weather reports only)
WT Weight
WTHR Weather
WTR Water
WTR Well To Right
WTRS Waters
WTSPT Waterspout
WTSPTS Waterspouts
WU Western Union Telegraph Company
WUD Would
WV Wave
WV Wind at altitude (PIREP only)
WVS Waves
WW Severe Weather forecast
WWAMKC Status Report
WWD Westward
WWS Severe Weather Watches
WWW World Wide Web
WX Weather
WX Weather at altitude (PIREP only)
WXCON Weather reconnaissance flight pilot report
WXR Weather Radar Transceiver
WXXM Weather Information Exchange Model
WYAIO Will You Accept; If Offered (position)

X                                                  

X Cross
X Obscured sky condition
X/W Crosswind
XBAR Crossbar
XCP Except
XCVR Transceiver
XDCR Transducer
XFMR Transformer
XFSS Auxiliary Flight Service Station
XH Special handling service for aircraft
XMIT Transmit
XML Extensible Markup Language
XMOS High speed metal oxide silicon semiconductor
XNG Crossing
XPC Expect
XPCD Expected
XPCG Expecting
XPCS Expects
XPDR Transponder
XPLOS Explosive
XREP Auxiliary Report
XS Atmospherics
XTAL Crystal
XTK Cross-Track
XTK DEV Cross Track Deviation
XTLK Cross Talk
XTND Extend
XTNDD Extended
XTNDG Extending
XTRM Extreme
XTRMLY Extremely
XW Crosswind
XX Heavy (to qualify weather phenomena, e.g. XXRA heavy rain)
Y                                                  
Y Yukon Standard Time (time groups only)
YCZ Yellow Caution Zone (runway lighting)
YD Yards
YD Yaw Damper
YDA Yesterday
YDM Yaw Damper Module
YES Yes (affirmative)
YKN Yukon
YL Approach Light lane
YLSTN Yellowstone
YMSG Your Message
YMSGD Your Message Date
YR Your
Z                                                  
Z Greenwich Mean Time
Z Zulu Time
ZAB Albuquerque ARTCC
ZAN Anchorage ARTCC
ZAU Chicago ARTCC
ZBW Boston ARTCC
ZDC Washington ARTCC
ZDV Denver ARTCC
ZFW Fort Worth ARTCC
ZFW Zero Fuel Weight
ZHU Houston ARTCC
ZI Zonal Index
ZI Zone of Interior
ZID Indianapolis ARTCC
ZJX Jacksonville ARTCC
ZKC Kansas City ARTCC
ZL Freezing drizzle
ZLA Los Angeles ARTCC
ZLC Salt Lake City ARTCC
ZM Z Marker (VHF station location marker)
ZMA Miami ARTCC
ZME Memphis ARTCC
ZMP Minneapolis ARTCC
ZN Zone
ZNS Zones
ZNY New York ARTCC
ZOA Oakland ARTCC
ZOB Cleveland ARTCC
ZR Freezing rain
ZRNO Freezing Rain information Not available (weather reports only)
ZSE Seattle ARTCC
ZTL Atlanta ARTCC
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Copyright © 2024 · ProAirPilot.com