TFRs and NOTAMs

TFRs ▶ Temporary Flight Restrictions (TFRs) are regulatory airspace restrictions established for a specific area and period of time to protect persons or property in the air or on the surface, provide a safe environment for disaster relief and emergency operations, protect certain governmental or public activities, or address other temporary hazards and security requirements. TFRs may be issued for wildfires, disaster areas, major public events, VIP movements, space operations, air shows, security events, and other circumstances requiring temporary control of the airspace. Because TFRs can be established or changed rapidly, pilots must specifically check for applicable TFRs during preflight planning and remain aware of changes that may occur after departure. ENTERING AN ACTIVE TFR WITHOUT AUTHORIZATION CAN CREATE A SERIOUS FLIGHT-SAFETY HAZARD and may result in interception, enforcement action, certificate sanctions, or other consequences. A TFR should never be treated as merely another item in a briefing; its location, dimensions, altitude limits, effective times, operating restrictions, and authorization requirements must be understood before operating anywhere near the affected airspace. FAA Active & Future Temporary Flight Restrictions (TFRs) Live TFR information supplied by the Federal Aviation Administration. Always verify TFR and NOTAM information with official FAA sources before flight. This is a live feed from the FAA. Scroll window below for current data: NOTAMs ▶ FAA: Notice to Airmen (NOTAM) — a notice containing time-critical information concerning the establishment, condition, or change of a facility, service, procedure, or hazard within the National Airspace System (NAS). Thorough review of applicable NOTAMs is a critical part of preflight planning and continued situational awareness. Runway closures, navigation outages, lighting failures, airspace restrictions, obstacles, and other hazards may not be apparent without consulting current NOTAM information. FATAL ACCIDENTS DO OCCUR when critical NOTAM information is missed, misunderstood, or inadequately incorporated into flight planning. Pilots should know where to obtain authoritative NOTAM information, review it before every flight, and remain alert for changes throughout the operation. Access current NOTAMs directly through the Federal Aviation Administration. Open FAA NOTAM Search ▶ NOTAM Acronyms A A Absolute A Alaskan Standard Time A Amber A Arctic (air mass) A/A Air to Air A/C Approach Control A/G Air to Ground A/H Already Had AAC Alaskan Air Command AAD Assigned Altitude Deviation AADC Approach and Departure Control AAF Army Air Field AAITVL Arrival Aircraft Interval AAL Above Aerodrome Level AAL Alaskan Region AAP Advise if Able to Proceed AAR Airport Arrival Rate AARTE Airport Acceptance Rate AATM At All Times AAWF Auxiliary Aviation Weather Facility AAWTA Advise at What Time Able AB Airborne ABBR Abbreviate ABCST Automatic Broadcast ABD Aboard ABI Advance Boundary Information ABLCHG Airborne Launching ABM Abeam ABN Aerodrome Beacon ABND Abandon ABNDT Abundant ABNML Abnormal ABT About ABV Above AC Advisory Circular AC Altocumulus AC Assistant Chief ACA Artic Control Area ACARS Aircraft Communication Addressing and Reporting System ACAS Airborne Collision Avoidance System ACC Altocumulus Castellanus ACC Area Control Center ACCID Notification of Aircraft Accident ACCT Account ACCUM Accumulate ACDNT Accident ACDO Air Carrier District Office ACE Central Region ACES Access ACFT Aircraft ACID Aircraft Identification ACK Acknowledge ACL Altimeter Check Location ACLD Above Clouds ACLS Automatic Carrier Landing System ACLT Accelerate ACM Air combat maneuvers ACN Aircraft Classification Number ACN All Concerned Notified ACNOT Accident Notice ACP Acceptance (message type designator) ACP Area Command Post ACPT Accept ACPY Accompany ACR Air Carrier ACRBT Acrobatic ACRS Across ACSL Standing Lenticular Altocumulus ACT Active or Activated or Activity ACT Air Combat Training ACT Technical Center ACTG Acting ACTV Active ACTVT Activate ACW Aircraft Control and Warning ACYC Anticyclonic AD Aerodrome ADA Advisory Area ADAP Airport Development Aid Program ADC Aerodrome Chart ADCF Air Defense Control Facility ADCON Advise or issue instructions to all concerned ADCUS Advise Customs ADDN Addition ADE Air Defense Emergency ADF Automatic Direction Finder ADFAP Automatic Direction Finder Approach ADIZ Air Defense Identification Zone ADJ Adjacent ADL Aggregate Demand List ADLO Air Defense Liaison Officer ADLY Arrival Delay ADMAP Advise by Air Mail as Soon as Possible ADMIN Administration ADMIR Administrator ADMIS Aircraft Departing at (number of minutes) Interval ADMIV Administrative ADNL TFC Additional Traffic ADNOK Advise if not correct ADO Aerodrome Office (specify service) ADO Airport District Office ADP Automatic Data Processing ADPE Automatic Data Processing Equipment ADPS Automatic Data Processing Systems ADQT Adequate ADR Advisory Route ADR Airport Departure Rate ADRDE Advise Reason for Delay ADRNDCK Adirondack ADRT Alternate Departure Route ADS Address ADS Air Defense Sector ADS Automatic Dependent Surveillance ADSPN Advise Disposition ADSU Automatic Dependent Surveillance Unit ADV Advise ADVALT Allotment Advice ADVC Advice ADVCTN Advection ADVN Advance ADVY Advisory ADVZY Advisory ADW Air Defense Warning ADZ Advise ADZAR Advise Arrival ADZI Advise Intentions ADZOF Advise This Office ADZY Advisory AEA Eastern Region AEM Aircraft and Engine Mechanic AENG Airways Engineer AER Approach End Runway AERO Aeronautical AES Aircraft Earth Station AEU Europe Africa and Middle East Office AEVAC Air Evacuation AEW Airborne Early Warning AFB Air Force Base AFC Area Forecast Center AFCT Affect AFD Airport Facility Directory AFDK After Dark AFIL Filed Flight Plan in the Air AFIO Authorization for Interceptor Operations AFIRM Affirmative AFIS Aerodrome Flight Information Service AFJ Air Force Jet AFM Affirmative AFNEA Air Force NOTAM Exchange Area AFNEO Air Force NOTAM Exchange Office AFOVRN Air Force Overrun (1000ft standard approach lighting system) AFREP Air Force Representative AFRT Air Freight AFS Aeronautical Fixed Service AFSS Automated Flight Service Station AFT After AFTN Aeronautical Fixed Telecommunications Network AFTN Afternoon AG Air Ground AGA Aerodromes Air Routes and Ground Aids AGACS Automatic Ground Air Ground Communication System A-GEAR Arresting Gear AGL Above Ground Level AGL Great Lakes Region AGN Again AGR Agree AGRMT Agreement AHD Ahead AI Arrival Approved Request for IFR Flight AIA Advise if Able AIATSC All International Air Traffic Switching Centers AIC Aeronautical Information Circular AID Airport Information Desk AIDC Air Traffic services Inter facility Data Communication AIFP Activate IFR Flight Plan AILS Automatic Instrument Landing System AIM Airman’s Information Manual AIP Aeronautical Information Publication AIRAC Aeronautical Information Regulation and Control AIRCOMNET Air Force Communications Network AIREP Air Report AIRFL Air Refueling AIRMET Airmen's Meteorological Information AIROPNET Air Operations Network AIS Aeronautical Information Service AIS Aeronautical Information Specialist AIS Airport in sight AL All Field Offices and Personnel AL Annual Leave AL/At Least (altitude) ALA Alighting Area ALACFO All Air Carrier Field Offices ALADLO All Air Defense Liaison Officers in Service Area ALAFFO All Technical Operations ALANO All Accident Notice Offices ALARTC All Air Route Traffic Control Centers in Service Area ALAT All Air Traffic Service Personnel in Service Area ALATAS All Air Traffic (area) Supervisors in Service Area ALATF All Air Traffic Field Facilities ALATFO All Air Traffic Field Offices ALCKT All Offices Having Send−receive Teletypewriter Service on Circuit ALCS/C All Air Traffic Combined Station/ Centers in Service Area ALCS/T All Air Traffic Combined Station/ Towers in Service Area ALCT Attempt to Locate ALDA Air Line Dispatchers Association ALERFA Alert Phase Code (alerting service) ALF Aloft ALFAB All Offices on NADIN ALFSFO All Flight Standards Field Offices ALFSS All Flight Service Stations in Service Area ALG Along ALGHNY Allegheny ALIATSC All International Aeronautical Telecommunication Switching Centers ALIFO All International Field Offices ALIFSS All International Flight Service Stations in Service Area ALNMT Alignment ALNOT Alert Notice ALP Airport Layout Plan ALPA Air Line Pilots Association ALQDS All Quadrants ALR Alerting ALRAFAC All Radar Facilities in Service Area ALRGN All Regional Service Area Offices ALS Approach Light System ALSEC All Sectors ALSF Approach Lighting System With Sequenced Flashing Lights ALSF1 Approach Lighting System With Sequenced Flashers Cat 1 ALSF-1 Approach Lighting System With Sequenced Flashers Cat 1 ALSF2 Approach Lighting System With Sequenced Flashers Cat 2 ALSF-2 Approach Lighting System With Sequenced Flashers Cat 2 ALSFI Approach Lighting System With Sequenced Flashers Cat 1 ALSF-I Approach Lighting System With Sequenced Flashers Cat 1 ALFSII Approach Lighting System With Sequenced Flashers Cat 2 ALSF-II Approach Lighting System With Sequenced Flashers Cat 2 ALSTG Altimeter Setting ALT Altitude ALTA Alberta ALTM Altimeter ALTN Alternate ALTPT Alternate Airport ALTRV Altitude Reservation ALTWR All Towers in Service Area ALUTN Aleutian ALWF Actual Wind Factor AM Ante Meridiem AMA Area Minimum Altitude AMB Ambiguity AMC Air Mobility Command AMC Mike Monroney Aeronautical Center AMCL Amended Clearance AMD Amend AMD Amended Forecast AMDT Amendment AMECH Account Mechanical AMGR Airport Manager AMIS Aircraft Movement Information Services AMOS Automatic Meteorological Observing System AMP Amplifier or Amplify AMPLTD Amplitude AMRF Amended Route of Flight AMS Aeronautical Mobile Service AMS Air Mass AMS American Meteorological Society AMSL Above Mean Sea Level AMSS Aeronautical Mobile Satellite Service AMT Amount AMVER Automated Mutual Assistance Vessel Rescue System ANC Aeronautical Chart ANCPT Anticipate ANCS Aeronautical Navigation Chart Small Scale ANE New England Region ANF Air Navigation Facility ANG Air National Guard ANLYS Analysis ANM Northwest Mountain Region ANMS Automatic Network Management System ANNC Announce ANR Advanced Navigation Routes ANRA Air Navigation Radio Aids ANS Answer ANT Antenna AO1 ASOS Automated Observation Without Precipitation Discriminator (rain/snow) AO2 ASOS Automated Observation With Precipitation Discriminator (rain/ snow) AOA At or Above AOAF At or After AOB At or Below AOBF At or Before AOC Aerodrome Obstacle Chart AOC Airport Operating Certificate AOCP Aircraft Out of Commission for Parts AOE Airport of Entry AOPA Aircraft Owners and Pilots Association AP Airport AP Anomalous Propagation APAP Approach Path Alignment Panel APAP This list is copywritten and belongs to proairpilot APAPI Abbreviated Precision Approach Path Indicator APC Area Positive Control APCH Approach APDC Aircraft parking/docking chart APL Airport Lights APLCN Appalachian APN Apron APNT Appoint APP Approach Control APP Approach Control Office APPA Advise Present Position and Altitude APPR Appear APR Airports Program Report APREQ Approval Request APRNT Apparent APROP Appropriate APRX Approximate APS Airborne Pulse Search Radar APSG After Passing APV Approve APVL Approval AR Atlantic Route ARAC Area Airports Checked ARAC Army Radar Approach Control Facility ARAD Altitude Radial ARB Air Reserve Base ARC Area chart ARCP Air Refueling Control Point AREP Air Refueling Egress Point AREX Air Refueling Exit ARFF Aircraft Rescue and Fire Fighting ARFFOK Airport Rescue and Fire Fighting Alarm Checked ARFOR Area Forecast ARINC Aeronautical Radio Incorporated ARIP Air Refueling Initial Point ARL Aerial ARLO Army Liaison Officer ARMET Forecast upper wind and temperature at specified points ARML Airmail ARND Around ARNG Arrange ARNOT Area Notice ARO Air Traffic Services Reporting Office ARO Airport Reservations Office ARP Aerodrome Reference Point ARP Airport Reference Point ARP Airport Reservation Position ARP Air Report ARPT Airport ARQ Automatic Error Correction Equipment ARR Arrival or Arrive ARS Air Rescue Service (USAF) ARS Special Air Report ARSA Airport Radar Service Area ARSR Air Route Surveillance Radar ARST Arrest ARTC Air Route Traffic Control ARTCC Air Route Traffic Control Center ARTS Automated Radar Terminal Systems ARU Airborne Radar Unit ARU Airspace Reservation Unit ARUNK Arrival Unknown AS Altostratus AS/R Automatic Send/Receive ASAP As Soon As Possible ASC Ascent to ASCU Automatic Scanning Control Unit ASD Airspace Docket ASDA Accelerate Stop Distance Available ASDE Airport Surface Detection Equipment ASE Altimetry System Error ASGN Assign ASI Altimeter Setting Indicator ASIP Airspace Flight Inspection Pilot ASL Above Sea Level ASMD Assumed ASN Antenna Structure Number ASND Ascend ASO Southern Region ASOS Automated Surface Observing System ASP Airport System Plan ASP Airspace ASPH Asphalt ASR Airport Surveillance Radar ASSOC Associate ASST Assistant ASW Southwest Region ATA Actual Time of Arrival ATA Air Transport Association of America ATAM At and Maintain ATAR Above Transmitted as Received Air Traffic Control ATC Air Traffic Control ATCA Air Traffic Control Association ATCA ATC Advises ATCAA ATC Assigned Airspace ATCBI ATC Beacon Interrogator ATCC ATC Clears ATCF ATC Facility ATCH Attach ATCOR ATC Operations Representative ATCR ATC Requests ATCRBS ATC Radar Beacon System ATCS ATC Specialist ATCSCC David J. Hurley Systems Command Center ATCT Airport Traffic Control Tower ATD Actual Time of Departure ATFC Account Traffic ATFM Air Traffic Flow Management ATIS Automatic Terminal Information Service ATLC Atlantic ATM Air Traffic Management ATM Authentication Maneuver ATMT Attempt ATMTC Attempt to Contact ATN Aeronautical Telecommunications Network ATND Attend ATO Aeronautical Telecommunications Operator ATO Air Traffic Organization ATOG Allowable Takeoff Gross Weight ATP Actual Time of Penetration ATP Air Traffic Procedures ATPAC Air Traffic Procedures Advisory Committee ATR Air Transport Rating ATREP Air Traffic Representative ATRLS Actual Time of Release ATSCCP Air Traffic Service Contingency Command Post ATT American Telephone and Telegraph Company ATTM At This Time ATTN Attention AT-VASIS Abbreviated T Visual Approach Slope Indicator System ATZ Aerodrome Traffic Zone AUGRA Authority Granted AURBO Aurora Borealis AUREQ Authority is Requested AUTH Authority AUTH Authorized AUTO Automatic AUTOB Automatic Weather Reporting System AUW All Up Weight (gross weight) AUX Auxiliary AUZ Authorize AVANA Altitude reservation void for aircraft not airborne by AVBL Available AVFP Activate VFR Flight Plan AVFPNO Pilot failed to activate VFR/DVFR flight plan AVG Average AVGAS Aviation Gasoline AVN Aviation AWA Advise When Able AWANS Aviation Weather and NOTAM System AWBE Automatic Weather Broadcast Equipment AWE Advise When Established AWL All Weather Landing AWOS Automatic Weather Observing/ Reporting System AWP Aviation Weather Processors AWP Western-Pacific Region AWS Air Weather Service (USAF) AWT Await or Awaiting AWX Account Weather AWY Airway AXPS Air Express AZM Azimuth AZRAN Azimuth and Range Data B B Base Leg B Beginning of precipitation (time in minutes) (weather reports only) B Bering Standard Time (time groups only) B Blue B Center clearance delivered BA Braking Action BAC Below All Clouds BACLIN Baroclinic or Baroclinic Prognosis BAFVC Bids Accepted for the Following Vacancies BAL Balance BASE Cloud Base BASOPS Base Operations Office BATROP Barotropic or Barotropic Prognosis BC Back Course BC Beginning Climb BC British Columbia BC Patchy BCFG Patchy fog BCH Beach BCKG Backing BCM Back Course Marker BCM Become BCN Beacon BCREQ Broadcast Requested BCST Broadcast BCSTN Broadcast Station BDA Bermuda BDAT Beacon Data (digitized) BDR Border BDRY Boundary BDSLD Bids Solicited BECMG Becoming BFDK Before Dark BFR Before BGN Began or Begin BGND Begin or Beginning Descent BHND Behind BIFR Before Encountering IFR Conditions BINOVC Breaks in Overcast BKN Broken BL Blowing BLD Build BLDG Building BLDU Blowing Dust BLDUP Buildup BLKHLS Black Hills BLKT Blanket BLN Balloon BLO Below BLO Below Clouds BLSA Blowing Sand BLSN Blowing Snow BLW Below BLX Block BLZD Blizzard BMBR Bomber BMS Basic Meteorological Services BND Bound BNDRY Boundary BNTH Beneath BOMB Bombing BOVC Base of Overcast BPOC Before Proceeding On Course BPS Bytes Per Second BPT Beginning Procedure Turn BR Bahama Route BR Branch BR Mist BRAF Braking Action Fair BRAG Braking Action Good BRAN Braking Action Nil BRAP Braking Action Poor BRF Brief BRG Bearing BRGT Bright BRITE Bright Radar Indicator Tower Equipment BRK Break BRKG Braking BRKHIC Breaks in Higher Overcast BRKSHR Berkshire BRM Barometer BS Commercial Broadcasting Station BSAF Bids Solicited as Follows BSC Bird Sweep Completed BSHP Beginning Standard Holding Procedure BSIAP Beginning Straight In Approach BSRAP Beginning Standard Range Approach BSRO Begin Standard Refuel Orbit BT Back Taxiing BTL Between Layers BTN Between BTR Better BTWN Between BUEC Backup Emergency Communication BUIC Backup Interceptor Control BUL Bulletin BUR Bureau BUS Business BY Blowing Spray (weather reports only) BYD Beyond BZR Buzzer (radar) C C Celsius C Central Standard Time (time groups only) C Centre (runway ID) C Circling (approach and landing charts) C Continental (air mass) C/A Coarse/Acquisition CA Clear Above (PIREP only) CAAS Class A Airspace CAC Change to Approach Control CAC Changing to Approach Control CAC Contact Approach Control CACT Civil Air Carrier Turbojet CADO Chief Airport District Office CAM Canadian Armed Forces Transport Command CAN Canada CANFORCE Canadian Armed Force CANO Catalogue Number CANOT Canadian NOTAM CANR Canadian NORAD Region CAO Change of Appointing Office CAP Civil Air Patrol CAP/IS Combined Approach Control/International Station CAPD Climb at Pilot’s Discretion CAPT Captain CARA Check Area Airports CARF Central Altitude Reservation Function CARIB Caribbean CARU Canadian Airspace Reservation Unit CAS Calibrated Airspeed CAS Collision Avoidance System CASCDS Cascades CAT Category CAT Clear Air Turbulence CATX Climb and Cross CAUFN Caution Advised Until Further Notice CAVOK Cloud and Visibility OK CAVU Clear or scattered clouds and visibility greater than ten miles CAWS Common Aviation Weather Subsystem CB Cumulonimbus CBAS Class B Airspace CBMAM Cumulonimbus Mamma CBSA Class B Surface Area CC Carbon Copy CC Cirrocumulus CCA Continental Control Area CCAS Class C airspace CCC Central Computer Complex CCC Regional Communications Control Center CCD City (or County) Civil Defense Director____ CCFP Collaborative Convective Forecast Product CCLDS Clear of Clouds CCLKOB Counterclockwise Orbit CCLKWS Counterclockwise CCRU Complete Crew CCRZ Climb and Cruise CCSA Class C Surface Area CCSL Standing Lenticular Cirrocumulus CCTLR Chief Controller CCUS Cleared Customs CD Candela CD Civil Defense CD Clearance Delivery CDAS Class D Airspace CDC Computer Display Channel CDFNT Cold Front CDM Collaborative Decision Making CDN Coordination CDO Communications Duty Officer CDSA Class D Surface Area CE Communications Equipment CEAS Class E Airspace CELNAV Celestial Navigation CENGR Civil Engineer CENPAC Central North Pacific CER Climb En Route CERAP Combined Center/RAPCON CERT Certificate CERTIF Certification CESA Class E Surface Area CF Change Frequency CFA Controlled Firing Area CFAD Composite Flight Data Processing CFADC Canadian Forces Air Defense Command CFAP Cleared for Approach CFM Confirm CFN Confine CFP Cold Front Passage CFPL Carryover From Previous Log CFR Code of Federal Regulations CFWSU Central Flow Weather Service Unit CFY Clarify CG Coast Guard CGAS Class G Airspace CGAS Coast Guard Air Station CGL Circling Guidance Light CGLS Coast Guard LORAN Station CGSTN Congestion CH Channel CH Channel continuity check of transmission to permit comparison of record of channel sequence numbers of messages received on the channel CHAP Chapter CHARC Characteristic CHC Chance CHG Change CHGO Changing Over CHM Chemicals CHNL Channel CHOK Check Okay CHOV Changeover CHRG Charge CHSPK Chesapeake CHTR Charter CI Cirrus CIC Controller in Charge CIDIN Common Data Interchange Network CIFP Cancel IFR Flight Plan CIFR Cancel IFR Clearance Previously Given CIFRR Common IFR Room CIG Ceiling CINCNORAD Commander in Chief North American Aerospace Defense Command CIRNAV Circumnavigate CIRNOT Circuit Notice CIRVIS Communications Instructions for Reporting Vital Intelligence Sightings CIT Near or over large towns CIV Civil CK Check CKT Circuit CL Centre Line CL Closing Station CL Course Line CLA Clear type of ice formation CLB Climb CLBI Climb Immediately CLBN Crash Locator Beacon CLBR Calibration CLD Cloud CLG Calling CLKOB Clockwise Orbit CLKWS Clockwise CLN Colon CLNC Clearance CLODA Closing Date CLOTO Close This Office CLR Clear CLRAP Cleared as Planned CLRS Clear and Smooth CLSD Closed CLST Celestial CLU Circuit Line Up CM Centimeter CMA Comma CMB Climb to or climbing to CMNC Commence CMPCT Compact CMPL Complete or completed or completion CMPLT Complete CMPLX Complex CMPSN Composition CMPT Component CMS Construction Maintenance Supervisor CMSN Commission CNCL Cancel CNCNT Concurrently CNCT Connect CNDN Canadian CNL Cancel CNLFP Cancel Flight Plan CNS Communications Navigation and Surveillance CNS Consolidated NOTAM System CNSTNT Consistent CNTR Center CNTRL Central CNTRLN Centerline CNVG Converge CNVRT Convert CNVSN Conversion CNVTV Convective CO Company CO County COB Close of Business COC Climb on Course COLL Collect COM Communication COMB Combine COML Commercial COMLO Compass Locator COMPR Compare COMPRT Compartment CONC Concrete CONCA Continue Calling Until COND Condition CONF Confidential CONFDC Confidence CONFIG Configuration CONFIGN Configuration CONR Continental NORAD Region CONS Continuous CONSO CONSOLAN Facility CONSOL Consol Beacon CONSOLAN Low or medium frequency long range navigational aid CONST Construction CONT Continue or continued CONTDVD Continental Divide CONTH Continue to Hold CONTR Contract CONTRAILS Condensation Trails COORD Coordinate COORD Coordinates COP Changeover Point COPCOM Controllers’ Operations and Procedures Committee COPT Completed Procedure Turn COR Correct or corrected or correction CORAS Corridor Assignment COREQ Confirming Requisition Follows COT At the coast COV Cover CP Circular Polarization CPA Crash Phone Activated CPBL Capable CPD Coupled CPDLC Controller Pilot Data Link Communications CPF Complete Power Failure CPL Current Flight Plan CPME Calibration Performance Monitoring Equipment CPN Air Transport Pulse Radar Navigation Aid CPS Air Transport Pulse Radar Search CPTY Capacity CRAD Composite Radar Data Processing CRAF Civil Reserve Air Fleet CRC Circle CRC Cyclic Redundancy Check CRCHF Crew Chief CRLC Circulate CRS Course CRT Cathode Ray Tube CRTFY Certify CRYPTO Cryptographic CRZ Cruise CRZAM Cruise and Maintain CRZWTR Cruise Well to Right CS Call Sign CS Cirrostratus CS/C Combined Station/ Center CS/T Combined Station/ Tower CSATR Climb so as to reach CSATX Climb so as to cross CSDR Consider CSDRBL Considerable CSLDT Consolidate CST Coast CTA Control Area CTAF Common Traffic Advisory Frequency CTAM Climb to and maintain CTAS Controlled airspace CTAX Climb to and cross CTC Contact CTCC Change to Center Control or Changing to Center Control CTCC Contact Center Control CTCEN Contact Center CTGY Category CTL Control CTLA Control Area CTLB Control Boundary CTLR Controller CTLZ Control Zone CTN Caution CTR Control Zone CTRAC Common Terminal Radar Approach Control CTSKLS Catskills CU Cumulus CUF Cumuliform CUFRA Cumulus Fractus CUSNO Customs has been Notified CUST Customs CVFP Cancel VFR Flight Plan CVINO Clearance Void if Not Off CVN Convene CVR Cockpit Voice Recorder CVR Cover CVRS Computerized Voice Reservation System CW Continuous Wave CWM Change Weight Manifest CWRC Climb Well to Right of Course CWSU Center Weather Service Unit CWTR Climb Well to Right CWY Clearway CXA Cancel Approved Arrival CXD Cancel Approved Departure CYC Cyclonic CYCLGN Cyclogenesis CYL Cylinder CZM Coastal Zone Management D D Danger Area DA Decision Altitude DA Departure Approved DAAR Deviation Approved As Requested DABRK Daybreak DAE District Airport Engineer DAIRE Direct Altitude and Identification Readout Equipment DALGT Daylight DAP Do All Possible DAPD Descend at Pilot’s Discretion DASI Digital Altimeter Setting Indicator DATIS Data Link Automatic Terminal Information Service DATIS Digital Automatic Terminal Information Service DB Decibel DB Describe DBA Doing Business As DBASI Digital Barometer Altimeter Setting Indicator DBL Double DBTF Doubtful DC Direct Current DCA Defense Communications Acy DCAVU Clear or scattered clouds and visibility greater than ten, remainder of report missing (weather reports only) DCD Double Channel Duplex DCF Deputy Chief DCKG Docking DCLRT Decelerate DCM Defense Combat Maneuvers DCMSN Decommission DCMT Document DCPC Direct Controller Pilot Communications DCR Decrease DCRZ Descend to and Cruise DCS Defense Communications System DCS Double Channel Simplex DCT Direct DDM Difference in Depth of Modulation DE From (used to precede the call sign of the calling station) DECCO Defense Commercial Communications Office DEF Defense DEFCON Defense Readiness Conditions DEG Degree DELPHO Deliver by Telephone DEMOL Demolition DENEB Fog Dispersal Operations DEP Depart DEP Departure DEPT Department DER Departure End of Runway DES Descend to or Descending to DESTN Destination DETRESFA Distress Phase Code Alerting DEV Deviation DEW Distant Early Warning DEWIZ Distant Early Warning Identification Zone DFCLT Difficult DFDR Digital Flight Data Recorder DFL Daily Flight Log DFNT Definite DFRS Differs DFTI Distance From Touchdown Indicator DFUS Diffuse DGCGO Dangerous Cargo DGNL Diagonal DGR Danger DH Decision Height DI Delay Indefinite DI Departure approval request for IFR flight DIAM Diameter DIF Diffuse DIR Director DISABLD Disabled DISC Discontinue DISEM Disseminate DIST Distance DIST District DISTR Distribute DIV Divert DIV Division DKTS Dakotas DLA Delay DLAC Delay Account Of DLAT Delay Time DLC Delay Clearance or Delayed Clearance DLIC Data Link Initiation Capability DLT Delete DLVR Deliver DLVY Delivery DLY Daily DMAAC Defense Mapping Acy Aerospace Center DMAHC Defense Mapping Acy Hydrographic Center DME Distance Measuring Equipment DME/P Precision Distance Measuring Equipment DMEG DME Co-located with Glide Slope DMEL DME Co-located with Localizer DMER DME Tactical air navigation with DME only commissioned DMEV DME Co-located with VOR DMG Damage DMNT Dominant DMO Directives Management Officer DMSH Diminish DMSTN Demonstration DNA Defense Nuclear Agency DNG Danger DNS Dense DNSLP Downslope DNSTRM Downstream DNWND Downwind DO Deputy Commander for Operations DO Ditto DOB Date of Birth DOC Department of Commerce DOD Department of Defense DOE Department of Energy DOLLY Data Link DOM Domestic DOT Department of Transportation DOT1 Transport One Secretary of Transportation DOT2 Transport Two Deputy Secretary of Transportation DP Deep DP Dew Point DPCR Departure Procedure DPNG Deepening DPT Depth DPTH Depth DR Dead Reckoning DR Direct Route DR Low Drifting DRCT Direct DRCTN Direction DRDU Low Drifting Dust DRFT Drift DRG During DRIR Direct Readout Infrared DRMS Distance Root Mean Square DRR Deployment Readiness Review DRSA Low Drifting Sand DRSN Low Drifting Snow DRZL Drizzle DS Domestic Services (island operations) DS Dust Storm DSATR Descend So as to Reach DSATX Descend So as to Cross DSB Double Sideband DSCNT Descent DSGND Designated DSIPT Dissipate DSN Defense Switching Network DSND Descend DSNDI Descend Immediately DSNT Distant DSPL Display DSPLC Displace DSPN Disposition DSPRL Dispersal DSR Desire DSRGD Disregard DST Distort DSTC Distance DSTND Destined DTAM Descend to and Maintain DTAX Descend to and Cross DTE Data Terminal Equipment DTF Data Transmission Feature DTG Date Time Group DTHR Displaced Runway Threshold DTL Detail DTLN International Dateline DTR Data Transmission Request DTRM Determine DTRT Deteriorate DTS Diplomatic Telecommunications Service DTW Dual Tandem Wheels DU Widespread Dust DUATS Direct User Access Terminal System DUC Dense Upper Cloud DUPE Duplicate DUPE Duplicate Message DUR Duration DURC During Climb DURD During Descent DURG During DURN Duration DV Distinguished Visitors DVFR Day Visual Flight Rules DVFR Defense Visual Flight Rules DVLP Develop DVOLMET Data Link DVOR Doppler VHF Omnidirectional Radio Range DVRG Diverge DVRSN Diversion DVV Downward Vertical Velocity DW Dual Wheels DWG Drawing DWNDFTS Downdrafts DWPNT Dew Point DWRC Descend Well to Right of Course DWTR Descend Well to Right DX Duplex DZ Drizzle E E East or Eastern longitude E Eastern Standard Time (time groups only) E Ending of precipitation (time in minutes) (weather reports only) E Equatorial (air mass) E/G Engineerator E/R Exchange and Repair EACLN Expect Approach Clearance EACNL Expect Approach Clearance Not Later Than EADIZ Entering Air Defense Identification Zone EARTS En Route Automated Radar Tracking System EAS Equivalent Airspeed EAT Expected Approach Time EB Eastbound EBND Eastbound ECA Enter Control Area ECAS Enter Controlled Airspace ECD Except Change Departure to Read ECM Electronic Counter Measures ECMSN Electronic Counter Measure Mission ECOM En Route Communications ECR Except Change Route to Read ECSP Electronic Specialist EDA Early Departure Authorized EDC Expect Departure Clearance At EDCT Estimated Departure Clearance EDR Expect Departure Release At EEE Error (to be used in AFS as a procedure signal) EEM Electronic Equipment Modification EENGR Electrical Engineer EEP End Exercise Point EET Estimated Elapsed Time EFA Entire Field Available EFAS En Route Flight Advisory Service EFC Expect Further Clearance At EFCT Effect EFF Effective EFR Expect Further Routing EFTO Encrypt for Transmission Only EG Emergency Gear EGECON Electronic Geographic Coordinator Navigation System EHA Expect Higher Altitude EHF Extremely High Frequency (30000 to 300000 MHz) EIT Electronic Installation Technician ELAT Estimated Latitude ELBA Emergency Location Beacon Aircraft ELEC Electric ELECN Electrician ELEV Elevate or elevation ELIP Elliptical ELMT Electronic Mechanic Technician ELNGT Elongate ELONG Estimated Longitude ELR Extra Long Range ELSW Elsewhere ELT Emergency Locator Transmitter EM Emission EMBD Embedded (in cloud layer) EMBDD Embedded EMDO Engineering and Manufacturing District Office EMERG Emergency EMI Electronic Maintenance Inspector EMSU Environment Meteorological Support Unit EMT Electronic Maintenance Technician ENCTR Encounter END Stopend (related to RVR) ENDCE Endurance ENDG Ending ENE East North East ENERN East North Eastern (weather reports only) ENEWD East North Eastward (weather reports only) ENG Engine ENGR Engineer ENHNCD Enhanced ENHNCMNT Enhancement ENR Enroute ENRC Enroute Chart (followed by name/ title) ENRT En Route ENTR Entire EOBT Estimated Off Block Time EOD Entered On Duty EOF Expected Operations Forecast EP En Route Penetration EPI Expanded Position Indicator EQCRT Equipment Certified EQPT Equipment EQUIP Equipment ER Here ERAD En Route Radar (broadband) ERMG En Route Metering ERSP En Route Spacing Program ERY Early ESCAT Emergency Security Control of Air Traffic ESE East South East ESEC En Route Secondary Radar Beacon ESERN East South Eastern ESEWD East South Eastward ESNTL Essential ESP En Route Sequencing Program EST Estimate or estimation ESTAB Establish ESV Expanded Service Volume ET Electronic Technician ETA Estimated Time of Arrival ETARS En route tracking automatic radar service ETC Et Cetera ETD Estimated Time of Departure ETE Estimated Time En Route ETFL Each Thousand Foot Level ETI Estimated Information ETIM Elapsed Time ETO Estimated Time Over Significant Point ETOV Estimated Time Over ETP Estimated Time of Penetration ETR Eastern Test Range EU Electronic Unit EUO Emergency Use Only EV Every EVAC Evacuation EVAL Evaluate or evaluation EVE Evening EVS Electronic Voice Switching System EVT Expect Vector To EXAM Examination EXC Except EXCH Exchange EXCLD Exclude EXCLV Exclusive EXCP Except EXCT Execute EXDLVY Expedite Delivery EXEC Executive EXEC1 President on board civil aircraft EXEC1F President’s family is aboard aircraft EXEC2 Vice President is aboard civil aircraft EXEC2F Vice President’s family is aboard aircraft EXER Exercise EXP Expect EXPC Expect EXPED Expedite EXPHO Expedite Delivery by Telephone EXPS Express EXQF Expanded Quota Flow EXREP Expedite Mail Reply EXSEC Extra Section EXSHI Expedite Shipment EXTD Extend EXTN Extension EXTRAP Extrapolate EXTRM Extreme EXTSV Extensive F F Cleared to fix F Fahrenheit F Flight Inspection FA Area Forecast FA CENTER Aviation Area Forecast Center FA Final Approach FA Fuel Advisory FAA Federal Aviation Administration FAA For an Approach To FAA1 SafeAir OneFederal Aviation Administration Administrator FAA2 SafeAir TwoFederal Aviation Administration Deputy Administrator FAAP Federal Aid to Airports Program FAC Facility FACF Facility Chief FACSFAC Fleet Area Controlled and Surveillance Facility FAD Fuel Advisory Departure FAF Final Approach Fix FAFAB FSS Assumes Flightplan Area and Service B FAH Fahrenheit FAL Facilitation of International Air Transport FAM Familiar or familiarization FAMAE Following Amendment Authorized Effective FAP Final Approach Point FAR Federal Aviation Regulations FATFL FSS Assumes Control of Tower Frequencies and Lights FAX Facsimile FBO Fixed Base Operator FC Funnel Cloud FCA Frequency Change Approved FCC Federal Communications Commission FCFSS Contract Flight Service Station FCO Facility Coordination Officer FCRP Field Condition Report FCST Forecast FCTA Flow Control Time of Arrival FCWOS Contract Weather Observing Station FDAT Flight Data FDC Flight Data Center FDDL Frequency Division Data Link FDEP Flight Data Entry and Printout FDI Fault Detection and Isolation FDIO Flight Data Input/Output FDIOR Flight Data Input/Output Repeater FDPS Flight Data Processing System FE Flight Engineer FENKN Fuel Supply Unknown FENTL Fuel Supply Until FEW Cloud Coverage 1/8th to 1/4th of sky FEXHA Fuel Supply Exhausted FFC For Further Clearance FFLT Familiarization Flight FFMN Fixed Federal Monitoring Network FFR Fire Fighting FG Fog FGSB FSS Guarding Service B FI/P Flight Information (permanent) FI/T Flight Information (temporary) FIBI Filed But Impracticable to Transmit FIC Flight Information Center FICON Field Condition FIDO Flight Inspection District Office FIFO Flight Inspection Field Office FIFOH Flight Inspection Field Office High Altitude FIFP Filed IFR Flight Plan FIG Figure FIG Flight Inspection Group FIL Filament FILG Filling FILS Florescan Instrument Landing System FINO Weather report will not be filed for transmission FIR Flight Information Region FIRAV First Available FIRB Flight Information Region Boundary FIRG Firing FIRIV Arrival report will be filed with FIS Flight Information Service FISA Automated flight information service FL Flash Advisory FL Flight Level FLCTN Fluctuation FLD Field FLDST Flood Stage FLG Falling FLG Flashing FLIDAP Flight Data Position FLIP Flight Information Publication FLORL Fluorescent Runway Lighting (floodlight system) FLR Flares FLRY Flurry FLT Flight FLTCK Flight Check FLTO Flight Orders FLTWO Flight Watch Outlet FLUC Fluctuating FLW Follow FLWIS Flood Warning Issued FM Fan Marker FM From FMAP Fan Marker Approach FMH Fan Marker Located with Radio Beacon FMO Frequency Management Officer FMS Flight Management System FMT Format FMU Flow Management Unit FNA Final Approach FNCTN Function FNT Front FNTGNS Frontoesis FNTLYS Frontolysis FOB Fuel On Board FOD Foreign Object Debris FONE Telephone FORNN Forenoon FP Flight Plan FPA Flight Plan Area FPB Flight Progress Board FPDI Flight Path Deviation Indicator FPL Filed Flight Plan FPL Full Performance Level FPM Feet Per Minute FPN Fixed Pulse Radar Navigation Aid FPNO Flight Plan Not Received FPP From Present Position FPR Flight Plan Route FPRC For Possible Reclearance FPWA Further Particulars When Available FQT Frequent FR Fuel Remaining FRC Full Route Clearance FRD Fix Radial Distance FREQ Frequency FRFAB FSS Returns Flight Plan Area and Service B FRH Fly Runway Heading FRM Form FRMG Forming FRMN Formation FRNG Firing FROPA Frontal Passage FROSFC Frontal Surface FRQ Frequent FRSB FSS Returns Service B FRST Frost FRTFL FSS Returns Control of Tower Frequencies and Lights FRWF Forecast Wind Factor FRZ Freeze FRZLVL Freezing Level FRZN Frozen FSDO Flight Standards District Office FSL Full Stop Landing FSM Flight Schedule Monitor FSNFO Flight Standards National Field Office FSP Flight Strip Printer FSS Flight Service Station FT Feet FT Filing Time FT Foot FTAR Following Transmitted as Received (message handling) FTHR Farther or further FTHRD Feathered FTS Federal Telecommunications System FU Smoke FURN Furnish FV Forward Visibility (miles) FVFP Filed VFR Flight Plan FW/SIFR Fixed Wing Special IFR FW/SVFR Fixed Wing Special VFR FWA Flight Watch Area FWC Fleet Weather Central FWCS Flight Watch Control Station FWD Forward FWDC Forward Collect FWP Flight Watch Point FWRNG Fire Warning FWS Flight Watch Specialist FWU Flight Watch Unit FYI For Your Information FZ Supercooled/freezing FZDZ Freezing Drizzle FZFG Freezing Fog FZRA Freezing Rain FZRANO Freezing Rain Sensor Not Available G G Green G Gusts reaching (knots) (weather reports only) G/A Ground to Air G/A/G Ground to Air and Air to Ground GA General Aviation GA Glide Angle GA Go ahead resume sending (to be used in AFS as a procedure signal) GADO General Aviation District Office GALS Gallons GBA Give Better Address GBAS Ground Based Augmentation System GBL Government Bill of Landing GBR Give Better Reference GC Ground Control GCA Ground Control Approach GCI Ground Control Intercept GCO Ground Communication Outlet GDP Ground Delay Program GDPGM Ground Delay Program GEO Geographic GEOREF Geographical Reference GES Ground Earth Station GHZ Gigahertz GIC GPS Integrity Channel GICG Glaze Icing GLD Glider GLDR Glider GLFALSK Gulf of Alaska GLFCAL Gulf of California GLFMEX Gulf of Mexico GLFSTLAWR Gulf of St Lawrence GLONASS Global Orbiting Navigation Satellite System GLS GBAS Landing System GMC Ground Movement Chart (followed by name/title) GMT Greenwich Mean Time GND Ground GNDCK Ground Check GNDFG Ground Fog GNSS Global Navigation Satellite System (in general) GNTR Generator GOV Governor GOVT Government GP Glide Path GPI Ground Point of Intercept GPS Global Positioning System GQA Get Quick Answer GR Hail (greater than 3/4”) GRAD Gradient GRADU Gradual GRASS Grass landing area GRBL Garble GRBNKS Grand Banks GRDL Gradual GRID Grid point values of processed meteorological data GRTLKS Great Lakes GRVL Gravel GS Glide Slope GS Ground Speed GS Ground Stop GS Snow pellets/small hail (less than 1/4”) GSA General Services Administration GSDO General Safety District Office GSI General Safety Inspector GSTS Gusts GSTY Gusty GTC Gain Time Control GTCL Great Circle GTR Greater GUND Geoid Undulation GV Ground Visibility GVG Giving GVH Government Vehicle GWT Gross Weight H H24 Continuous 24 hour service HAA Height Above Airport HADA Hawaiian Defense Area HADD Hawaiian Air Defense Division HADIZ Hawaiian Air Defense Identification Zone HAL Height Above Landing HANG Hawaiian Air National Guard HAPI Holding as Previously Instructed HARS Hazardous Area Reporting Service HAT Height Above Touchdown HAZ Hazard HAZMAT Hazardous Material HB Homing Beacon HBN Hazard Beacon HCVIS High Clouds Visible HDATZ High Density Traffic Zones HDF High Frequency Direction Finding Station HDFRZ Hard Freeze HDG Heading HDOP Horizontal Dilution of Precision HDSVLY Hudson Valley HDTA High Density Traffic Airport HDWND Headwind HEAD Head of State Status HEL Helicopter HELI Heliport HF High Frequency HFR Hold for Release HGT Height HHE Household Effects HI High HIALS High Intensity Approach Light System HIBAL High Altitude Balloon HIEAT Highest Temperature Equaled for all Time HIEFM Highest Temperature Equaled for the Month HIESE Highest Temperature Equaled so Early HIESL Highest Temperature Equaled so Late HIFOR High Level Forecast HIRIV How will arrival report be filed concerning HIRL High Intensity Runway Lights HITMP Highest Temperature HIWAS Hazardous Inflight Weather Advisory Service HIXAT Highest Temperature Exceeded for all Time HIXFM Highest Temperature Exceeded for the Month HIXSE Highest Temperature Exceeded so Early HIXSL Highest Temperature Exceeded so Late HJ Sunrise to sunset HLDG Holding HLF Half HLSTO Hailstones HLTP Hilltop HN Sunset to sunrise HND Hundred HNGR Hangar HO Service available to meet operational requirements HOL Holiday HOP Handoff Point HOP Helicopter Operations HOSP Hospital Aircraft HOW Handover Word HP Holding Pattern HPA Hectopascal HQ Headquarters HR Here HR Hour HRZN Horizon HS Service available during scheduled operations HTN Heterodyne HTR Heater HUM Humanitarian Mission HURCN Hurricane HUREP Hurricane Report HV High Voltage HVDF High and very high frequency direction finding stations HVY Heavy HWVR However HWY Highway HX High Index HX No specific working hours HYD Hydraulic HYDRO Hydrographic HYR Higher HZ Haze Hz Hertz I I/IFR Intermittent Instruments IAARC International Administrative Aeronautical Radio Conference IAC Instrument Approach Chart IAD If Authorized DME May be Used IAF Initial Approach Fix IAO In and out of clouds IAP Instrument Approach Procedure IAR Intersection of Air Routes IAS Indicated Air Speed IATA International Air Transport Association IATSC International Aeronautical Telecommunications Switching Center IAW In Accordance With IBASF Intervals Between Aircraft in Stream Type Formation IBN Identification Beacon IBND Inbound IC Ice Crystals IC Icing (PIREP only) ICAO International Civil Aviation Organization ICD Interface Control Document ICG Icing ICGIC Icing in Clouds ICGICIP Icing in Clouds and Precipitation ICGIP Icing in Precipitation ID Identify or identifier IDAT Interfacility Data IDENT Identification IDP Individual Development Plan IF Intermediate approach fix IF Intermediate Fix IFAMP If Approach Missed Proceed IFF Identification Friend/Foe IFHOL If Holding IFIM International Flight Information Manual IFINS If Instrument Conditions Encountered IFO International Field Office IFO Interphone IFONO Interphone (service F) not operative IFORO Interphone (service F) resumed operation IFPFP Individual Flight Plans from this Point IFR Instrument Flight Rules IFSS International Flight Service Station IFUN If Unable IFVLS If Flight Visibility Becomes Less Than IFVR If Visibility Remains IGA International General Aviation IGIA Interacy Group on International Aviation IIA If incorrect Advise IISD If incorrect Service Direct ILAS Instrument Low Approach ILS Instrument Landing System ILSP Instrument Landing System Partial IM Inner Marker IMAP Immediately After Passing IMC Instrument Meteorological Conditions IMDT Immediate IMF Interrogation Sign IMG Immigration IMI Intensity Unknown IMP Impracticable IMPL Impulse IMPR Improve IMPT Important IMT Immediate or immediately IN Inch INA Initial Approach INADQT Inadequate INATS Interruption of Air Traffic Services INBD Inbound INC In Clouds INC Incorporated INCERFA Uncertainty phase code (alerting service) INCL Include INCLV Inclusive INCOMP Incomplete INCOR Incorrect INCR Increase INDC Indicate INDEF Indefinite INDUS Industrial INF Inland Navigation Facility INFO Information INIT Initial Training INLD Inland INOF If not off INOP Inoperative INP If Not Possible INPR In Progress INREQ Information Request INS Inertial Navigation System INSP Inspect INST Instrument INSTA Instruments Authorized INSTA Interstate INSTBY Instability INSTL Install INSTR Instruct INSTR Instrument INSUF Insufficient Scheduled Time Available INSUF Unable to Finish INT Intersection INTCNTL Intercontinental INTCP Intercept INTD Intend INTER Intermittent INTFC Interference INTL International INTMD Intermediate INTMT Intermittent INTNS Intentions INTR Interior INTRG Interrogator INTRMTRGN InterMountain Region INTRP Interrupt INTS Intense INTSF Intensify or intensifying INTSFY Intensify INTST Intensity INTVL Interval INTXN Intersection INVES Investigate INVOF In the Vicinity Of INVRN Inversion INVSTAR Investigate and report IOVC In Overcast IP Initial Point IP Instructor Pilot IP/HHCL Initial Point/Hour Control Line IPV Improve IR Ice on Runway IR IFR Military training route IRAC Interdepartmental Radio Advisory Committee IRAD Inbound Radial IREG Irregular IRN Interface Revision Notices IS Island ISA International Standard Atmosphere ISB Independent Sideband ISMGR Island Manager ISMLS Interim Standard Microwave Landing System ISOL Isolate ITCK Issue Time Check ITNRNT Itinerant ITRY Itinerary ITU International Telecommunications Union IVFRC In VFR Conditions J JAL Jet Approach Landing Charts JATO Jet Assisted Takeoff JAWYS Join Airways JBAR Jet Runway Barrier JCTN Junction JOUR Journeyman JP Jet Penetration JPAP Jet Penetration Approach JTST Jet Stream JTSTR Jet Stream K K Cold (air mass) KC Kilocycles KEPOA Keep this Office Advised KFRST Killing Frost KG Kilogram KHZ Kilohertz KIAS Knots Indicated Airspeed KM Kilometers KMH Kilometers Per Hour KPA Kilopascal KT Knots KW Kilowatt L L Left L Locator L Logistics L/MF Low/Medium Frequency LA Low Approach LAA Local Airport Advisory LAADR Low Altitude Arrival/Departure Routing LAAS Local Area Augmentation System LAB Laboratory LABRDR Labrador LABS Leased Service A/B System LABS Low Altitude Bombing System LADP Local Airport Deicing Plan LAM Logical Acknowledgment LAN Inland LARCT Last Radio Contact LAT Latitude LAWRS Limited Aviation Weather Reporting Station LB Left Base LB Pounds LC Local Control LCA Locally LCL Local or locally LCT Locate LCTMP Little Change in Temperature LD Long Distance LDA Landing Distance Available LDA Localizer Type Directional Aid LDG Landing LDI Landing Direction Indicator LDIN Lead in Lighting System LEN Length LETFO Letter Follows LF Low Frequency LFC Laminar Flow Control LFNT Low Frequency Intersection LFR Low Frequency Radio Range LFT Lift LGRNG Long Range LGT Light LGTD Lighted LGWV Long Wave LICOF Land Lines Communications Facilities LIFR Low IFR LIH Light Intensity High LIL Light Intensity Low LIM Light Intensity Medium LIN Linearity LIRL Low Intensity Runway Edge Lights LK Lake LKLY Likely LKTYP Like Type LL Landline LLWAS Low Level Wind Shear Alert System LLWS Low Level Wind Shear LLZ Localizer LM Locator Middle LMM Compass locator at ILS middle marker LMT Limit LMT Local Mean Time LN Line LNAV Lateral Navigation LND Land LNDG Landing LO Liaison Officer LO Outer Locator LOA Letter of Agreement LOC Localizer LOCOR Local Coordinator LODISNAV Long Distance Navigation LOEAT Lowest Temperature Equaled for all Time LOEFM Lowest Temperature Equaled for the Month LOESE Lowest Temperature Equaled so Early LOESL Lowest Temperature Equaled so Late LOM Compass locator at ILS outer marker LONG Longitude LONGL Longitudinal LOP Line of Position LORAC Long Range Accuracy LORAN Long Range Air Navigation System LOTMP Lowest Temperature LOXAT Lowest Temperature Exceeded for all Time LOXFM Lowest Temperature Exceeded for the Month LOXSE Lowest Temperature Exceeded so Early LOXSL Lowest Temperature Exceeded so Late LP Left Traffic Pattern LP Linear Polarization LP Liquid Propane LP Localizer Performance Without Vertical Guidance LPV Localizer Performance With Vertical Guidance LR The last message received by me was LRA Landing Rights Airport LRCOM Long Range VHF/UHF Communications LRG Large LRG Long Range LRS Lake Reporting Service LS Left Side LS Last message sent by me was or last message was LSQ Line Squall LSR Loose Snow on Runway LST Local Standard Time LT Turn left after takeoff LTAV Light and Variable LTD Limited LTF Local Training Flight LTFC Landing Traffic LTGCA Lightning Cloud to Air LTGCC Lightning Cloud to Cloud LTGCCCG Lightning Cloud to Cloud Cloud to Ground LTGCG Lightning Cloud to Ground LTGCW Lightning Cloud to Water LTGIC Lightning in Clouds LTL Little LTLCG Little Change LTNG Lightning LTR Later LTR Letter LTT Landline Teletypewriter LTTR Latter LV Leaving LV Light and Variable LVE Leave or leaving LVG Leaving LVL Level LVLOF Level Off LWR Lower LX Low Index LYR Layer or layered or layers M M In RVR indicates visibility less than lowest reportable sensor value (e.g. M600) M In temperature field means “minus” or below zero M Mach number M Maritime (air mass) M Metres (preceded by figures) M Missing (weather reports only) M Mountain Standard Time (time groups only) MA Map Analysis MAA Maximum Authorized (IFR) Altitude MAC Military Airlift Command MACH MACH Number (speed ratio to speed of sound) MACKAY Mackay Radio and Telegraph Company MACVFR Make Altitude Changes VFR MAFAP Minimum Altitude over Facility on Final Approach Course MAG Magnetic MAGSI Minimum Altitude at Glide Slope Intersection Inbound MAINT Maintenance MAL Maintain at Least (altitude) MALS Medium-Intensity Approach Lighting System MALSF Medium-Intensity Approach Light System with Sequenced Flashers MALSR Medium-Intensity Approach Lighting System With Runway Alignment Indicator MAM Maintenance Assumes Monitor MAN Manitoba MAN Manual MANAM Manual Amendment MANOP Manual of Operations MAP Aeronautical Maps and Charts MAP Missed Approach Point MAPS Meteorological Aeronautical Presentation System MAPT Missed Approach Point MAR At sea MARPT Municipal Airport MARSA Military Assumes Responsibility for Separation of Aircraft MAS Manual A1 Simplex MAS Military Alert System MAX Maximum MB Marker Beacon MB Millibars MCA Minimum Crossing Altitude MCAS Marine Corps Air Station MCAS(H) Marine Corps Air Station (Helicopter) MCK Maintenance Check MCS Master Control Station MCW Modulated Continuous Wave MCZNE Minimum When Control Zone Effective MDA Minimum Descent Altitude MDF Medium Frequency Direction Finding Station MDFR Make Descent From MDFY Modify MDH Minimum Descent Height MDT Moderate MDZ Modernize MDZN Modernization MEA Minimum En Route Altitude MECH Mechanic MED Medical MED Medium MEDEVAC Medical Emergency Evacuation MEGG Merging MEHT Minimum Eye Height Over Threshold MEML Memorial MET Meteorological aviation routine weather report METOF Meteorological Officer METRO Metropolitan MEX Mexico MF Medium Frequency MFL Maintain Flight Level MFOB Minimum Fuel on Board MFPOF Master Flight Plan on File MFS Military Flight Service MFV Forward visibility more than (miles) MFXT Meter Fix Time MGAT Make Good a Track of (degrees) MGMT Make Good a Magnetic Track of (degrees) MGMT Management MGR Manager MHA Minimum Holding Altitude MHDF Medium and High Frequency Direction Finding Station MHDG Magnetic Heading MHFR Military Height Finder Radar MHKVLY Mohawk Valley MHVDF Medium High and Very High Frequency Direction Finding Station MHz Megahertz MI Manufacturing Inspector MI Mile MI Shallow MID Middle MID Midpoint (related to RVR) MID/ASIA Middle East/Asia Region MIDIZ MidCanada Identification Zone MIDN Midnight MIDPT Midpoint MIFG Patches of shallow fog not deeper than two meters MIJI Meaconing Intrusion Jamming Interference MIL Military MIMNO Mimeographic Notice MIN Minute MINIT Minutes in Trail MIREQ Minimum Requirements Specified MIRL Medium Intensity Runway Edge Lights MIS Missing MISC Miscellaneous MISG Missing MISL Missile MIT Miles in Trail MITO Minimum Interval Takeoff MKCT Make Check Turn MKD Marked MKR Marker MKR Marker Radio Beacon MLS Microwave Landing System MLTLVL Melting Level MM Middle Marker MM Millimeter MMACH Maintain Mach MMO Main Meteorological Office MNLD Mainland MNLY Mainly MNM Minimum MNPS Minimum Navigation Performance Specification MNPSA Minimum Navigation Performance Specification Airspace MNT Monitor MNTN Maintain MNVR Maneuver MOA Memorandum of Agreement MOA Military Operations Area MOC Minimum Obstacle Clearance MOCA Minimum Obstruction Clearance Altitude MOD Moderate MOD Modulate or modulation or modulator MOGR Moderate or Greater MON Above mountains MONOK Monitor resumed normal operation MONOS Monitor out of service MONTR Monitor MOPS Minimum Operational Performance Standards MOPTAR Multiobject Phase Tracking and Ranging MOREPS Monitor Station Reports MOT Ministry of Transport (Canada) MOTNE Meteorological Operational Telecommunications Network Europe MOV Move MPH Miles Per Hour MPP Merit Promotion Program MPS Meters Per Second MPVA Maintain a Position VFR and Advise MRA Minimum Reception Altitude MRG Medium Range MRGL Marginal MRM Maintenance Returns Monitor MRNG Morning MRP ATS/MET Reporting Point MRR Mechanical Reliability Report MRTM Maritime MRU Military Radar Unit MS Minus MSA Minimum Safe/sector Altitude MSAW Minimum Safe Altitude Warning MSG Message MSGCTR Message Center MSL Mean Sea Level MSR Message (transmission identification) has been misrouted MSSR Monopulse Secondary Surveillance Radar MSTLY Mostly MSTR Moisture MT Mountain MTCA Minimum Terrain Clearance Altitude MTI Moving Target Indicator MTN Mountain MTR Military Training Route MTRL Material MTRY Momentary MTU Metric Units MTW Mountain Wave MU Friction value representing runway surface conditions MUA Maximum Usable Altitude MUF Maximum Usable Frequency MULT Multiple MUNI Municipal MV Millivolt MVA Minimum Vector Altitude MVDF Medium and very high frequency direction finding station MVFR Maintain VFR MVFR Marginal VFR MVSP Maintain Visual Separation MWO Meteorological Watch Office MWRC Maintain Well to Right of Course MWTCS Modernized Weather Teletypewriter Communications System MXD Mixed N N North or northern latitude N/A Not Applicable NA National Air Traffic Controllers Association NA Not Authorized NAAS Naval Auxiliary Air Station NAATS National Association of Air Traffic Control Specialists NAB Not Above NACOS National Communications Schedule NADIN National Airspace Data Interchange Network NAF Naval Air Facility NAFEC National Aviation Facilities Experimental Center NANAC National Aircraft Noise Abatement Council NAP Not at Present NAPRS National Airspace Performance Reporting System NAR North American Route NAR Not According to Routine NAS National Airspace System NAS Naval Air Station NAS Navigation and Collision Avoidance System NASA National Aeronautics and Space Administration NASC National AIS System Centre NASEO National Airways System Engineering Office NASP National Airport System Plan NAT North Atlantic NAT Not ARTS tracked NATL National NATR No Additional Traffic Reported NATS Noise Abatement Test System NAV Navigation NAVAID Navigational Aid NAVLO Navy Liaison Officer NAVREP Navy Representative NB New Brunswick NB Northbound NBCAP National Beacon Code Allocation Plan NBFR Not Before NBND Northbound NBRHD Neighborhood NC National Air Transport Coordinating Committee NC No Change NCDC National Climatic Data Center NCE No Change in Estimates NCS National Communications System NCWX No Change in Weather NDB Nondirectional Radio Beacon NDB/DME NDB and DME (collocated) NDBLO Not to Descend Below NE Northeast NEB Northeastbound NEC Necessary NEF No Further Clearance Required NEG Negative NELY Northeasterly NERN Northeastern NESS National Environmental Satellite Service NETR No Essential Traffic Reported NEW ENG New England NFDC National Flight Data Center NFDD National Flight Data Digest NFLD Newfoundland NFQ Night Frequency NFT No Filing Time NFU Not For Us NG National Guard NGT Night NHD Not Heard NICS National Airspace System Interfacility Communications System NIL None NIL Unable to transmit NIS Not in System NL No Layers NLT Not Later Than NM Nautical Mile NMBR Number NMC National Meteorological Center NML Normal NMN No Middle Name NMR Nautical Mile Radius NMRS Numerous NNE North North East NNERN North North Eastern NNEWD North North Eastward NNW North North west NNWRN North North Western NNWWD North Westward NO Not available NOAA National Oceanic and Atmospheric Administration NOAC No Action Necessary NOF NOTAM Office NOFIN No Further Information NOHOL Not Holding NOIFN No Information NOM National Communications Center NOMAD Naval Oceanographic Meteorological Automatic Device NONEG Negative replies not required NONRVSM Non-RVSM Capable Flight NOPAC North Pacific NOPAR Do not pass to Air Defense radar NOPT No Procedure Turn Required NORAC No Radio Contact NORAD North American Aerospace Defense Command NORDO No Radio NOREC No Record NOREP No Report NORIV No Arrival Report NORPI No pilot balloon observation will be filed next collection unless weather changes significantly NORR No Reply Received NORST No Restrictions NOS National Ocean Service NOSI now Simultaneous NOSIG No Significant Change NOSPL No Special Observations Taken (weather reports only) NOSUM NOTAM Summary NOTAM Notice to Air Missions NOTAM Notice to Airmen (No longer used) NOZ Normal operating zone NPI Nonprecision Instrument NPRL No Parallel Traffic NPRM Notice of Proposed Rulemaking NPRS Nonpersistent NR Near NR Number NRAB Naval Reserve Air Base NRD No Record of Destination NRH No Reply Heard NRP North American Route Program NRV Nonrevenue NRW Narrow NS Nimbostratus NS Nova Scotia NSC No Significant Clouds NSC Nonstandard C/A Code NSCSWD No Small Craft or Storm Warning are Being Displayed NSP Nonstandard Holding Pattern NSSFC National Severe Storm Forecast Center NSTP Nonstop NSW No Significant Weather NTAP National Track Analysis Program NTAP Notices To Airmen Publication NTE Not to Exceed NTFND No Trouble Found NTFY Notify NTL National NTO Name to NTRP No Traffic Reported NTSB National Transportation Safety Board NTZ No Transgression Zone NUDET Nuclear Detonation NVA Negative Vorticity Advection NW Northwest NWB Northwestbound NWLY Northwesterly NWRN Northwestern NWS National Weather Service NWSO Naval Weather Service Office NXT Next O O/F On File O/R On Request O/T Overtime OA Overhead Approach OAC Oceanic Area Control OAG Official Airline Guide OANDR Operation and Regulation OAOI On and Off Instruments OARTS Oceanic Air Route Tracking System OAS Obstacle Assessment Surface OAT Outside Air Temperature OB On Board OBL Obliterate OBND Outbound OBS Observation OBSC Obscure obscured or obscuring OBST Obstacle OBST Obstruct OBSTN Obstruction OC Obstruction Chart OC On Course OCA Obstacle Clearance Altitude OCA Oceanic Control Area OCAC Oceanic OCAS Out of Controlled Airspace OCFNT Occluded Front OCH Obstacle Clearance Height OCL Obstacle Clearance Limit OCLD Occlude OCLN Occlusion OCNL Occasional OCR Occur OCS Obstacle clearance surface OCTLA Out of Control Area ODALS Omnidirectional Approach Lighting System ODAPS Oceanic Display and Planning System OFAS Overseas Flight Assistance Service OFC Office OFFL Official OFM Out For Maintenance OFP Occluded Frontal Passage OFP Original Flight Plan OFSHR Offshore OFW Off Watch OFXT Outer Fix Time OFZ Obstacle free zone OG On Ground OGN Originate OHD Overhead OI On Instruments OINT Omni Intersection OIS Operational Information System OJT On The Job Training OK Operating Normally OK We agree or it is correct OLDI On Line Data Interchange OLS Optical Landing System OM Outer Marker OMSG Our Message OMTNS Over Mountains ONER Oceanic Navigational Error Report ONSHR On Shore ONT Ontario ONW On Watch OOT Out of Tolerance OPA Opaque white type of ice formation OPC Operational Control OPDT Opposite Direction Traffic OPER Operate OPMET Operational Meteorological (information) OPN Open OPN Operation OPNML Operations Normal OPR Operate Operator Operational OPS Operations OPSNET Operations Network ORD Order ORGPHC Orographic ORIG Original ORL Overrun Lights ORS Over Range Station OSV Ocean Station Vessel OT Oral Notice OT On Time OTAS On Top and Smooth OTFC Overflight Traffic OTLK Outlook OTP On Top OTR Other OTRW Otherwise OTS Organized Track System OTS Out of Service OUBD Outbound OV Location (PIREP only) OVC Overcast OVD Overdue OVHD Overhead OVLA Overlay OVNGT Overnight OVR Over OVRN Overrun OVSEA Overseas OVTK Overtake OW One Way OWF Optimum Working Frequency OXY Oxygen P P In RVR indicates visibility greater than highest reportable sensor value P Pacific Standard Time P Polar (air mass) P Precision approach terrain chart P Prohibited Area P/CG Pilot Controller Glossary P6SM Visibility greater than 6 SM (TAF only) PA Precision Approach PA Pressure Altitude PAC Pacific PACF Parent FSS assumes control of part time FSS PADRA Pass to Air Defense Radar PAEW Personnel and Equipment Working PAJA Parachute Jumping Activities PALS Precision Approach Lighting System PALT Present Altitude PANS Procedures for Air Navigation Services PAP ProAirPilot PAPI Precision Approach Path Indicator PAR Precision Approach Radar PARA Paragraph PAREN Parenthesis PARL Parallel PARROT Position Adjustable Range Reference Orientation Transponder PAT Pattern PATWAS Pilots Automatic Telephone Weather Answering Service PAU Present Address Unknown PAX Passenger PBCT Proposed Boundary Crossing Time PBL Probable PBS Public Buildings Service PCA Positive Control Area PCD Proceed PCK Pilot Check PCL Pilot Controlled Lighting PCN Pavement Classification Number PCPN Precipitation PCS Permanent Change of Station PD Period PDAR Preferential Arrival/Departure Route PDC Predeparture Clearance PDDC Proceed Directly on Course PDMT Predominant PDMT Predominate PDOP Position Dilution of Precision PDR Preferential Departure Route (Stage A) PDW Priority Delayed Weather PEN Peninsula PENT Penetrate or penetration PER Performance PERCOM Peripheral Communications PERF Perforator PERM Permanent PFSV Pilot to Forecaster Service PGTSND Puget Sound PHYS Physical PIB Preflight Information Bulletin PIBAL Pilot Balloon Observation PIC Pilot in Command PIR Precision Instrument Runway PIREP Pilot Weather Report PIRFC Pilot Requests Forecast PISE No pilot balloon observation due to unfavorable sea conditions PISO No pilot balloon observation due to snow PIT Pilot Instructor Training PIWI No pilot balloon observation due to high, or gusty, surface wind PJE Parachute Jumping Exercise PK WND Peak Wind PL Ice Pellets PLA Practice Low Approach PLASI Pulsating Visual Approach Slope Indicators PLAT Present Latitude PLF Private Line Telephone PLN Flight Plan PLOB Place of Birth PLONG Present Longitude PLS Please PLT Private Line Teletypewriter PLVL Present Level PLW Plow (snow) PM Post Meridiem PMSN Permission PMT Permit PN Prior Notice Required PNHDL Panhandle PNR Point of No Return PO Dust Devils PO Post Office PO Purchase Order POA Privately Owned Aircraft POB Persons On Board POC Proceed or Proceeding On Course POS Positive POSS Possible POV Privately Owned Vehicle PP Pay Period (number) PPI Plan Position Indicator PPINA Radar weather report not available (or omitted for a reason different than those otherwise stated) PPINE Radar weather report no echoes observed PPINO Radar weather report equipment inoperative due to breakdown PPIOK Radar weather report equipment operation resumed PPIOM Radar weather report equipment inoperative due to maintenance PPR Prior Permission Required PPS Propose PPSN Present Position PR Partial PR Photo Reconnaissance PRBL Probable PRBLTY Probability PRBO Position Relief Briefing Observed PRCF Parent FSS returns control of part time FSS PRCHT Parachute PRCTN Precaution PRECD Precede PREF Preferred PRES Pressure PRESFR Pressure Falling Rapidly PRESRR Pressure Rising Rapidly PREV Previous PRFG Fog Partial PRI Primary PRIM Primary PRIN Principal PRIND Present Indications Are PRIRA Primary Radar PRJMP Pressure Jump (weather reports only) PRKG Parking PRN Pseudo Random Noise PROB Probability PROB30 Probability 30 Percent PROB40 Probability 40 Percent PROC Procedure PROCD Proceed PROG Prognosis or prognostic PROG Progress PROP Propeller PROPA Propagation PROSIG Procedure Signal PROV Provisional PRP Prepare PRSNT Present PRST Persist PRVD Provide PS Passenger Service PS Plus PSBL Possible PSBT Pilot Self Briefing Terminal PSG Passage PSG Passing PSGR Passenger PSN Position PSNAL Personal PSNL Personnel PSNRP Position Report PSP Pierced Steel Planking PSR Packed Snow on Runway PSR Primary Surveillance radar PSRI Position Subject to Return of Incumbent PSRS Position Subject to Rotating Shifts PST Pacific Standard Time PT Procedure Turn PTC Plan to Clear PTC Positive Target Control PTCHY Pitchy PTCP Participate PTLY Partly PTN Portion PTN Procedure Turn PTP Point To Point PTR Printer PTS Polar Track Structure PUB Public PUBL Publish PUP Pickup PVA Positive Vorticity Advection PVASI Pulsating Visual Approach Slope Indicator PVL Prevail PVLT Prevalent PVT Private PWB Pilot Weather Briefing PWI Proximity Warning Indicator PWINO Precipitation identifier information not available (weather reports only) PWR Power PWRNO Power Failure PWROK Power Restored PY Spray Q QDL Question asking for a series of bearings typically used in ICAO QDM Magnetic Heading QDR Magnetic Bearing QFE Atmospheric pressure at airport elevation QFLOW Quota Flow Control Procedures QFU Magnetic orientation of runway QJH Shall I run my test tape/a test sentence QLFY Qualify QLTY Quality QN Question QNH Altimeter subscale setting to obtain elevation when on the ground QNTY Quantity QSP Question asking for free of charge relay in ICAO QSTNRY Quasi Stationary QTA Shall I cancel telegram number? QTE True bearing QTR Quarter QUAD Quadrant QUE Quebec QUJ Questions asking for TRUE track in degrees and time in ICAO R R Acknowledgment of receipt (message handling) R Received (acknowledgment of receipt) R Restricted area (followed by identification) R Right (runway identification) R Runway (used in RVR measurement) R/O Receive Only R/OC Receive Only Centers RA Rain RAA Remote Airport Advisory RAAF Royal Australian Air Force RABA No RAWIN observation no balloons available RABAL Radiosonde balloon wind data RABAR Radiosonde balloon release RAC Request Altitude Change RAC Rules of the Air and Air Traffic Services RACE Request Altitude Changes En Route RACFI Radio and Communication Facilities Inoperative RACO No RAWIN Observation Communications Out RACON Radar Responder Beacon RADAT Radiosonde Observation Data RADEP Radar Departure RADNO Report missing account radio failure RADON Radar Beacon RADU Weather Radar Analysis and Development Unit RAF Royal Air Force RAFC Regional Area Forecast Center RAFI Radiosonde Observation Not Filed RAFRZ Radiosonde Observation Freezing Levels RAG Ragged RAG Runway Arresting Gear RAGF Remote Air Ground Facility RAHE No RAWIN observation no gas available RAI Runway Alignment Indicator RAICG Radiosonde Observation Icing At RAIL Runway Alignment Indicator Lights RAIM Receiver Autonomous Integrity Monitoring RAJAM Radar Jamming RALT Regardless of Altitude RAM Returned Account Mechanical RAOB Radiosonde Observation RAPCON Radar Approach Control RAPI Radiosonde report already sent in RARAD Radar Advisory RAREP Radar Weather Report RASC Regional AIS System Centre RASH Rain Showers RASN Rain and snow or showers of rain and snow RAVU Radiosonde Analysis and Verification Unit RAWE No RAWIN observations unfavorable weather RAWI No RAWIN observations high and gusty winds RAWIN Upper winds observation (by radio methods) RAWX Returned Account Weather RB Rescue Boat RB Right Base RBDE Radar Bright Display Equipment RBN Radio Beacon RBOC Report Back on Course RBOF Report Back on Frequency RBS PP (RBS) Ration by schedule plus compression RBS Radar Bomb Scoring RC Reverse Course RC Road Reconnaissance RCA Reach Cruising Altitude RCADV Reverse Course and Advise RCAG Remote Communications Air Ground Facility RCALT Reach Cruising Altitude RCC Rescue Coordination Center RCD Radar Cloud Detection Report RCDNA Radar Cloud Detection Report Not Available RCDNE Radar Cloud Detection Report No Echoes Observed RCDNO Radar cloud detector inoperative due to breakdown until RCDOM Radar cloud detector inoperative due to maintenance until RCF Radio Communication Failure RCF Remain on Company Frequency RCH Reach RCK Radio Check RCKY Rockies (mountains) RCL Runway Center Line RCLL Runway Center Line Lights RCLM Runway Centerline Marking RCLR Radio Communications Link Repeater RCLS Runway Centerline Light System RCLT Radio Communications Link Terminal RCMD Recommend RCN Royal Canadian Navy RCO Remote Communication Outlet RCOM En Route Communications RCON Reconfiguration RCPT Receipt RCR Runway Condition Reading RCRD Record RCS Rehost Computer System RCV Receive RCVNO Receiving Capability Out RDARA Regional and Domestic Air Route Area RDAT Radar Data RDC Reduce RDG Ridge RDH Reference Datum Height (ILS) RDL Radial RDO Radio RDS Radius RDSP Redispatch RDSPA Redispatch Accepted RDWND Radar Dome Wind RE Regard REC Receive or receiver RECLR Recleared RECON Reconnaissance RECON Reference Conversation REDL Runway Edge Light REF Reference REFONE Reference our telephone conversation REFORM Reference Form REG Registration REG Regulation REGAL Range and Elevation Guidance for Approach and Landing REIB Report Established in Block REIL Runway End Identifier Lights REINV Reference Invoice RELBL Reliable RELCT Relocate RELET Reference Letter REMES Reference Message REMT Relief Electronic Maintenance Technician RENL Runway End Light RENOT Regional Office Notice REOC Report When Established On Course REP Report or reporting point REP Represent or representative REP Research Project REPAML Reply By Airmail REPBS Reference PBS message REPERF Reperforator REPMES Reply By Message REPML Reply By Mail REPTWX Reply By TWX REQ Request REQID Request If Desired REQON Request Consideration REQRCM Request Your Recommendation REQSTD Requested RERTE Reroute RES Reserve RES Resident RESA Runway End Safety Area RESP Response RESTR Restrict REWRC Report When Established Well to Right of Course RF Radar Facility RF Radio Frequency RF Reception Fair RFA Request Further Airways RFI Radio Frequency Interference RFI Ready For Issue RFL Refuel RFS Refuse RFTO Ready For Takeoff RG Range (lights) RG Reception good RGD Ragged RGLR Regular RGN Region RH Relative Humidity RHC Right Hand Circuit RHI Range Height Indicator RHINO Radar Echo Height Information Not Available RHINO Radar Range Height Indicator Not Operating on Scan RIF Reclearance In Flight RIF Reduction In Force RIMAT Must Ride Company Material RIOGD Rio Grande RIS Reports Identification Symbol RITC Request in Trail Climb RITD Request in Trail Descent RITE Right (direction of turn) RL Report immediately upon leaving RL Report Leaving RLA Relay To RLANO Relay equipment out of operation RLAOK Relay equipment resumed operation RLBG Relative Bearing RLC Report Landing Completed RLCE Request Level Change En Route RLETFL Report Leaving Each Thousand Foot Level RLLS Runway Leading Lighting System RLNA Request Level Not Available RLS Release RLSTN Relay Station RLTK Rhumbline Track RLTV Relative RLV Relieve RLVL Report Level RM Remarks RMK Remark RMLR Radar Microwave Link Repeater RMLT Radar Microwave Link Terminal RMN Remain RMPCK Ramp Check RMRK Remark RN Reception Nil RNAV Area Navigation RNFL Rainfall RNG Army National Guard RNG Radio Range RNLS Resume Normal Speed RNP Required Navigation Performance RO Regional Office RO Regulated Output ROBEPS Radar Operating Below Prescribed Standard ROBEX Regional OPMET Bulletin Exchange ROC Rate of Climb ROCC NORAD Region Operations Control Center ROD Rate of Descent RODA Regardless of Destination Airport ROFOR Route Forecast ROLET Reference Letter from our office ROMEMO Reference Our Memorandum ROMES Reference Message from our office RON Remaining Overnight ROPBS Reference PBS message from our office RORQN Reference requisition from our office RORU Rest Of Route Unchanged ROT Rotate ROTEL Reference telegram from our office ROTG Rotating ROTWX Reference our TWX ROV Report Over RP Reception Poor (radio logs only) RP Right Traffic Pattern RPA Request Present Altitude RPD Rapid RPFOD Reported For Duty RPI Radar Position Indicator RPL Repetitive Flight Plan RPLC Replace RPM Rotation Per Minute RPOC Report Proceeding On Course RPR Repair RPRT Report RPS Radar Position Symbol RPSG Report Passing RPT Repeat RPT Repeat or I repeat RQ Indication of a request RQ Request RQCL Request Clearance RQDCZ Request Clearance to Depart VFR and Leave Control Zone at RQECZ Request Clearance to Enter Control Zone VFR at RQMNTS Requirements RQN Requisition RQOF Request on File RQP Request Flight Plan RQP Request Permission RQPP Request Present Position RQR Require RQRP Request Reply RQS Request Supplementary Flight Plan RQTAO Request Time and Altitude Over RR Low or medium frequency radio range stations RR Radar Range Station RR Report immediately upon reaching RR Report Reaching RRBN Round Robin RRCVR Remote Receiver RRL Runway Remaining Lights RRP Runway Reference Point RRPD Runway Reference Point Downwind RRPU Runway Reference Point Upwind RRS Remainder of Same Route RRTE Reroute RS Receiver Station RS Record Special Observation (weather reports only) RS Right Side RSC Rescue Subcenter RSCD Runway Surface Condition RSCU Rescue RSG Rising RSN Reason RSOPN Resumed Operation RSP Responder Beacon RSR En Route Surveillance Radar RSTR Restrict RSU Runway Supervisory Unit RSVN Reservation RT Right turn after takeoff RT Round Trip RTB Return To Base RTD Delayed RTE Route RTF Radiotelephone RTG Radiotelegraph RTHL Runway Threshold Light RTMTR Remote Transmitter RTN Return RTND Retained RTNE Routine RTO Report Time Over RTR Remote Transmitter/Receiver RTR Returning To Ramp RTRD Retard RTRN Return RTS Return To Service RTT Radio Teletypewriter RTX Report time crossing RTZL Runway Touchdown Zone Light RUF Rough RUFORM Reference your form RULET Reference letter from your office RUMEMO Reference your memorandum RUMES Reference message from your office RURQN Reference requisition from your office RUT Standard regional route transmitting frequencies RUTEL Reference telegram from your office RUTWX Reference your TWX RV Radar Vector RV Rescue Vessel RVO Runway Visibility by Observer RVR Runway Visual Range RVRA Runway Visual Range (RVR) ten minute average RVRANO Runway Visual Range (RVR) ten minute average not available RVRENO Runway Visual Range (RVR) ten minute extremes not available RVRM Runway Visual Range (RVR) midpoint RVRMNO Runway Visual Range (RVR) midpoint not available RVRNO Runway Visual Range (RVR) not available RVRR Runway Visual Range (RVR) rollout RVRRNO Runway Visual Range (RVR) rollout not available RVRT Runway Visual Range (RVR) touchdown RVRTNO Runway Visual Range (RVR) touchdown not available RVS Revise RVV Runway Visibility Value RVSM Reduced Vertical Separation Minimums RVVNO RVV not available RWRC Remain Well to Right of Course RWY Runway RY Runway S S South or southern latitude S/A Semiannual S/RC Send/Receive Center SA Duststorm, sandstorm, rising dust or sand SA Record Observation (weather reports only) SA Sandstorm or dusting SA Surveillance Approach SABH Simultaneous Automatic Broadcast Homer SADT Same Direction Traffic SAFI Semiautomatic Flight Inspection SAFI Semiautomatic Flight Inspection Aircraft SALS Short Approach Lighting System SALS Simple Approach Lighting System SALSF Short Approach Lighting System with Sequenced Flashing Lights SAN Sanitary SAO Surface Aviation Observation SAP Soon As Possible SAPD Speed at Pilots Discretion SAR Search and Rescue SARPS Standards and Recommended Practices SASK Saskhewan SATFY Satisfy or satisfactory SATR So As To Reach SAVASI Simplified Abbreviated Visual Approach Slope Indicator SAWRS Supplementary Aviation Weather Reporting Station SAYTA Say Time Able SB Southbound SBAS Satellite-Based Augmentation System SBFC Standby For Further Clearance SBND Southbound SBSD Subside SC Stratocumulus SCAN Self Correcting Automatic Navigation SCANO Automatic Scanning Unit Out of Service SCAOK Automatic Scanning Unit Returned to Service SCAT Security Control of Air Traffic SCATANA Security Control of Air Traffic and Air Navigation Aids SCC System Command Center SCLN Semicolon SCND Second (in line) SCS Single Channel Simplex SCSL Standing Lenticular Stratocumulus SCT Scattered SCTR Sector SCTY Security SDB Scheduled Data Base SDBY Standby SDF Simplified Directional Facility SE Southeast SE System Engineer SEADRM Seadrome SEB South Eastbound SEC Second (time) SECMR Sector Manager SECRA Secondary Radar SECT Sector SEL Space Environment Laboratory SELCAL Selective Calling SELS Severe Local Storms SELY South Easterly (weather reports only) SENS Sensitivity SEPN Separation SEQ Sequence SER Service SERN South Eastern SES Supervisory Electronics Specialist SESC Space Environment Service Center SET Stack Entry Time SEV Severe SF Standard Form SFA Single Frequency Approach SFC Surface SFERICS Atmospherics SFL Sequence Flashing Lights SFO Sector Field Office SFO Simulated Flame Out SFPP Stored Flight Plan Program SFU Sector Field Unit SG Snow Grains (weather reports only) SGD Signed SGD Solar Geophysical Data SGFNT Significant SGL Signal SH Showers SHF Super High Frequency SHFT Shift SHGR Hail Showers SHGS Hail Showers (small) SHLW Shallow SHORN Short Range Navigation System SHP Standard Holding Procedure SHPL Ice Pellet Showers SHRA Rain Showers SHRT Short SHRTLY Shortly SHRTWV Shortwave SHSN Snow Showers SHTDN Shutdown SHUD Should SHWR Shower SI Straight In Approach SIA Standard Instrument Approach SIAP Standard Instrument Approach Procedure SID Standard Instrument Departure SIERNEV Sierra Nevada SIF Selective Identification Feature SIG Signature SIGMET Significant Meteorological Information SIGWX Significant Weather SIM Simulated Approach SIMUL Simultaneous SIR Snow and Ice on Runway SIWL Single Isolated Wheel Load SJP Standard Jet Penetration SK Sky condition SKC Sky clear SKED Schedule SL Sea Level SL Sick Leave SLCT Select SLD Solid SLGT Slight SLMM Simultaneous Compass Locator at Middle Marker SLO Slow SLOM Simultaneous Compass Locator at Outer Marker SLP Sea Level Pressure SLP Slope SLP Speed Limiting Point SLR Slush on Runway SLRAP Standard Low Frequency Range Approach SLS Side Lobe Suppression SLT Sleet SLW Slow SM Statute Mile SMC Squawk Mode Code SMC Surface Movement Control SML Small SMR Statute Mile Radius SMR Surface Movement Radar SMRY Summary SMS Synchronous Meteorological Satellite SMS Systems Maintenance Sector SMT Submit SMTH Smooth 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 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 SNSH Snow Showers SNW Snow SNWFL Snowfall SOAP Spectrometric Oil Analysis Program SOB Souls On Board SOCC NORAD Sector Operations Control Center SOM Satellite Communication SOMSG See Our Message SOP Standard Operating Procedure SORAP Standard Omni Range Approach SP Standard Holding Pattern SP Station Pressure SPAN Stored Program for Alpha Numerics SPB Seaplane Base SPCLY Especially SPD Speed SPEC Specification SPECI Aviation selected special weather report SPKL Sprinkle SPL Special SPL Supplementary Flight Plan SPLNS South Plains SPO Strategic Plan of Operation SPOT Spot Wind SPRD Spread SPRL Spiral SPS Standard Positioning Service SPT Strategic Planning Team SQ Squall SQDN Squadron SQK Squawk SQLN Squall Line SR Standard Range Approach SR Sunrise SRA Surveillance Radar Approach SRCH Search SRE Surveillance Radar Element of precision approach radar system SRG Short Range SRND Surround SRPN Special Requisition Priority Number SRR Search and Rescue Region SRY Secondary SS Sandstorm 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 SSE South South East SSERN South South Eastern SSEWD South South Eastward SSNO Request no SIDs or STARs SSR Secondary Surveillance Radar SST Supersonic Transport SSW South South West SSWRN South South Western SSWWD South South Westward ST Saint ST Stratus STA Straight In Approach STADMR Station Administrator STAGN Stagnation STALO Stabilized Local Oscillator STAR Standard Terminal Arrival STATE Military, customs, or police services STBL Stable STCLB Start Climb STD Standard STDST Start Descent STDY Steady STF Stratiform STFRA Stratus Fractus STFRM Stratiform STG Strong STLT Satellite STM Storm STMGR Station Manager STMP Special Traffic Management Program STN Station STNR Stationary STNRY Stationary STOL Short Takeoff and Landing STR Subject Terminal Control Release STRO Stereo Routes STS Status STWL Stopway Light STWY Stopway SUA Special Use Airspace SUB Substitute SUBFIX Subject to Correction SUBJ Subject to SUF Sufficient SUG Suggest SUP Supply SUPCHG Supercharge SUPPL Supplement SUPPS Regional Supplementary Procedures SUPR Superior SUPSD Supersede SUPT Superintendent SUPVR Supervisor SURPIC Surface Picture SUSP Suspend SVC Service SVCBL Serviceable SVFR Special VFR SVG Serving SVN Space Vehicle Number SVR Severe SVRL Several SW South West SWAP Severe Weather Avoidance Plan SWB Scheduled Weather Broadcast SWB South Westbound SWLG Swelling SWLY South Westerly SWRN South Western SWSL Supplemental Weather Wervice Location SWY Stopway SX Stability Index SXN Section SYD Release Subject Your Discretion 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/R Transportation Request TA Temperature (PIREP only) TA Total Aboard TA Transition Altitude TAC Terminal Area Chart TACAN Tactical Air Navigational Aid TACLO Tactical Air Command Liaison Officer TACR Tactical Air Navigation TAD Tower Approach and Departure Control Facility TAF Terminal Aerodrome Forecast TAIL Tail Wind TAND Tandem TANDA Time and Attendance Report TAO TACAN only TAO Time and Altitude Over TAPER Temporary Appointment Pending Establishment of a Register TAR Terminal Area Surveillance Radar TARND Turn Around TARS Terminal Automated Radar Services TARS Tethered Aerostat Radar System TAS True Air Speed TASR Terminal Area Surveillance Radar TAWOG Travel Arrangements Without Government Expense TB Turbulence (PIREP only) TBJT Turbojet TC Time Check TC Tropical Cyclone TCA Tactical Customer Advocate TCA Terminal Control Area TCAS Traffic Alert and Collision Avoidance System TCH Threshold Crossing Height TCHD Threshold Crossing Height Downwind TCHU Threshold Crossing Height Upwind TCNTL Transcontinental TCOM Terminal Communications TCP Transfer of Control Point TCU Towering Cumulus TD Touchdown TD Transmitter Distributor TDA Today TDEL Time Delay TDLS Terminal Data Link System TDO Tornado TDOP Time Dilution of Precision TDWR Terminal Doppler Weather Radar TDY Temporary Duty TDZ Touchdown Zone TDZE Touchdown Zone Elevation TDZL Touchdown Zone Light (system) 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 TELRY Telegraph Reply TEMP Temperature TEMPO Temporary TEND Trend TERPS Terminal Instrument Procedures TET Tetrahedron TF Terrain Following TFC Traffic TFMS Traffic Flow Management System TFR Temporary Flight Restriction TFRCD Traffic Received TFZ Traffic Zone TGL Touch and Go Landing TGS Taxiing Guidance System THD Thunderhead THDR Thunder THK Thick THLD Threshold THN Thin THR Threshold THRFTR Thereafter THRU Through THRUT Throughout THSD Thousand THTN Threaten TIBA Traffic Information Broadcast by Aircraft TIL Until TINOP Transponder Inoperative TIP Until Past TIPS Terminal Information Processing System TKOF Takeoff TLM Telemetry TLRNC Tolerance TLTP Too Long To Print TLWD Tailwind TM Time (PIREP only) TM Traffic Management TMA Terminal Control Area TMPA Traffic Management Program Alert TMPRY Temporary TMT Transmit TMW Tomorrow TNA Turn Altitude TNDCY Tendency TNGT Tonight TNH Turn Height TNTV Tentative TO Travel Order TOC To Be Continued TOC Top of Climb TOD Time of Delivery TODA Takeoff Distance Available TOG Takeoff Gross Weight TOP Cloud top TOR Time of Receipt TOR Traffic on Request TORA Takeoff Run Available TOT Time of Transmission TOVC Top of Overcast TP Turning Point TP Type Aircraft (PIREP only) TPA Traffic Pattern Altitude TPG Topping TR Track TR VFR low altitude training routes TRA Temporary Reserved Airspace TRACAB Terminal Radar Approach Control in Tower Cab TRACON Terminal Radar Approach Control Facility TRAD Terminal Radar TRAN Transient TRANS Transmit or transmitter TRBL Trouble TRCV Tricolor Visual Approach Slope Indicator TRG Training TRIB Tributary TRK Track TRLVL Transition Level TRML Terminal TRMT Terminate TRNG Training TRNSP Transport TROF Trough TROP Tropopause TRPCD Tropical Continental (air mass) TRPCL Tropical TRPLYR Trapping Layer TRRN Terrain TRSA Terminal Radar Service Area TRSN Transition TRTD Treated TS Team Supervisor TS Thunderstorm TSA Transportation Security Administration TSATLC TransAtlantic TSEC Terminal Secondary Radar Beacon TSFR Transfer TSGR Thunderstorm with Hail TSGS Thunderstorm with Small Hail TSMNO Transmitting Capability out of Service TSMOK Transmitting Capability Returned to Service TSNO Thunderstorm Information Not Available TSNT Transient TSO Technical Standard Order TSPAC TransPacific TSPL Thunderstorm with Ice Pellets TSRA Thunderstorm with Rain TSSA Thunderstorm with Duststorm or sandstorm TSSN Thunderstorm with Snow TSTM Thunderstorm TT Teletypewriter TTS Teletype Switching Facilities TTY Teletypewriter Station TURB Turbulence TURBC Turbulence TURBT Turbulent TVASIS T Visual Approach Slope Indicator System TVL Travel TVOR Terminal VOR TWD Toward TWEB Transcribed Weather Broadcast TWI Twilight TWR Aerodrome Control Tower TWR Tower TWRG Towering TWS Radar Track While Scan TWX Teletypewriter Exchange Service TWY Taxiway TWYL Taxiway Link TXG Taxiing TXL Taxilane TXT Text 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 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 UAS Unmanned Aircraft Systems UAT Until Advised by the Tower UCDWN Until Cleared Down UCLT Until Cleared to Land by the Tower UD Unable to approve departure for the time specified UDDF Up and Down Drafts UDF Ultra High Frequency Direction Finding Station UERE User Equivalent Range Error UFA Until Further Advised 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 UHDT Unable Higher Due Traffic UHF Ultra High Frequency UIC Upper Information Center UIR Upper Flight Information Region ULDT Unable Lower Due Traffic ULR Ultra Long Range UM Unable to Maintain UN Unable 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 UNID Unidentified 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 UNTC Unable to Establish Contact UNUSBL Unusable UP Unknown Precipitation UPDFTS Up Drafts UPDT Update UPR Upper UPSLP Upslope UPSTRM Upstream UQOT Unquote URAUZ You are authorized URG Urgent URIZR Your recommendation is requested U/S Unserviceable USA U.S. Army USAF U.S. Air Force USAFIB U.S. Army Aviation Flight Information USBL Usable USCG U.S. Coast Guard USMC U.S. Marine Corps USN U.S. Navy USNO United States Naval Observatory USNOF United States NOTAM Office USNS United States NOTAM System USP Urgent Special Observation (weather reports only) UTA Upper control area UTC Coordinated Universal Time UTCOK Coordinated Universal Time Coordinate Check Completed UUA Urgent PIREP UVV Upward Vertical Velocity UW Upwind UWNDS Upper Winds V V Variable (weather reports only) VA Victor Airways VA Volcanic Ash VAC Visual Approach Chart VACAPES Virginia Capes VADA VFR Arrival Delay Advisory VAL Valleys VAN Runway control van VAPS V/STOL Approach System VAR Magnetic Variation VAR Visual Aural Radio Range VARN Variation VASI Visual Approach Slope Indicator VASIS Visual Approach Slope Indicator System VC Vicinity VCFG Fog in Vicinity VCNTY Vicinity VCOT VFR Conditions On Top VCTR Vector VDF Very High Frequency Direction Finding Station VDOP Vertical Dilution of Precision VDP Visual Descent Point VER Vertical VF Maintaining Visual Flight VFLT Visual Flight VFPR Via Flight Planned Route VFR Visual Flight Rules VFRSA VFR Restrictions Still Apply VFY Verify VHF Very High Frequency VIA By way of VIP Very Important Person VIP Visual Integrated Presentation VIS Visibility VLCTY Velocity VLF Very Low Frequency VLFD Via Low Frequency Direct VLNT Violent VLR Very Long Range VLY Valley VM Voice Modulation VMC Visual Meteorological Conditions VNAV Vertical Navigation VOD Via Omni Direct VOL Volume VOLMET Meteorological information for aircraft in flight VOPR Voice Operated Relay VOR Very High Frequency Omnidirectional Range VOR APPR VOR Approach 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 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 VR Veer VR VFR military training routes VRB Variable VRBL Variable VRG Visual Reference Gate VRISL Vancouver Island, BC VRT MOTN Vertical Motion VSA By visual reference to the ground VSB Visible VSBY Visibility VSBYDR Visibility Decreasing Rapidly VSBYIR Visibility Increasing Rapidly VSL Vessel VSP Vertical Speed VSPI Visual Glide path Indicator VSTOL Vertical/Short Takeoff and Landing VTOL Vertical Takeoff and Landing VV Vertical Visibility (indefinite ceiling) W W Warm (air mass) W West or western longitude W White WA AIRMET WAAS Wide Area Augmentation System WAC World Aeronautical Chart WAFC World Area Forecast Center WAIOP Will Accept If Offered the Position WB Westbound WBAR Wing Bar Lights WBND Westbound WBRBN Will Be Reported by NOTAM WBRH Weather Bureau Regional Headquarters WBTS Whereabouts WCLC Watch Check List Completed 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 WEF With Effect From WFO Weather Forecast Office 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 WIE With Immediate Effect WILCO Will Comply WINT Winter WINTEM Forecast upper wind and temperature for aviation WIP Work In Progress WK Weak WKDAY Weekday WKEND Weekend WKN Weaken WL Will WLAV Will Advise WMO World Meteorological Organization WMSC Weather Message Switching Center WND Wind WNW West North West WNWRN West North Western WNWWD West North Westward WO Washington Office WO Without WP Waypoint 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 WRNG Warning WRS Worse WS SIGMET WS Weak Signals WS Wind Shear WSCMO Weather Service Contract Meteorological Observatory WSHFT Wind Shift WSO Weather Service Office WSOM Weather Service Operations Manual WSP Weather System Processor (replacement for LLWAS) WSR Wet Snow on Runway WSSF National Weather Service Support Facility WSSU National Weather Service Support Unit WSTCH Wash Range WSW West South west WSWRN West South Western WSWWD West South Westward WT Weight WTR Water WTR Well To Right WTSPT Waterspout WU Western Union Telegraph Company WV Wave WV Wind at altitude (PIREP only) WW Severe weather forecast WWW World Wide Web WX Weather WX Weather at altitude (PIREP only) WXCON Weather reconnaissance flight pilot report WYAIO Will You Accept if Offered the Position of X X Cross X Obscured sky condition XBAR Crossbar XCP Except XFSS Auxiliary Flight Service Station XH Special handling service for aircraft XNG Crossing XPC Expect XPLOS Explosive XREP Auxiliary Report XS Atmospherics XTAL Crystal XTLK Cross Talk 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 YDA Yesterday 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 Jet terminal area ZI Zonal Index ZI Zone of Interior ZM Z marker (VHF station location marker) ZRNO Freezing Rain Information Not Available Acronym information sourced from ProAirPilot.