ICAO - Indicates International Civil Aviation Organization usage. International messages should use these. METAR/TAF - Indicates ICAO weather usage. AContraction Definition Usage +FC tornado/water spout METAR A absolute (temperature) NWS A Alaskan Standard Time (time groups only) NWS A Amber GEN A arctic (air mass) NWS A/A air to air ATC A/C approach control ATC A/G air to ground ICAO A/H already had ATC AAC Alaskan Air Command GEN AAD Assigned altitude deviation ICAO AADC approach and departure control ATC AAF Army Air Field GEN AAITVL arrival aircraft interval ATC AAL Above aerodrome level ICAO AAL Alaskan Region, FAA GEN AAP Advise if able to proceed ATC AAR airport arrival rate ATC AARTE airport acceptance rate ATC AATM at all times GEN AAWF Auxiliary Aviation Weather Facility NWS AAWTA Advise at what time able ICAO AB Airborne ATC ABBR Abbreviate GEN ABCST automatic broadcast GEN ABD Aboard GEN ABI Advance boundary information ICAO ABLCHG airborne launching ATC ABM abeam ICAO ABN aerodrome beacon ICAO ABND abandon GEN ABNDT abundant GEN ABNML abnormal GEN ABT about GEN ABV above ICAO AC Advisory Circular GEN AC altocumulus NWS AC assistant chief GEN ACA artic control area ATC ACARS Aircraft communication addressing and reporting system ICAO ACAS airborne collision avoidance system ICAO ACC area control center ATC ACC altocumulus castellanus NWS ACCID notification of aircraft accident ATC ACCT account GEN ACCUM accumulate GEN ACDNT accident GEN ACDO Air Carrier District Office GEN ACE Central Region, FAA GEN ACES access GEN ACFT aircraft ICAO ACID aircraft identification ATC ACK acknowledge GEN ACL altimeter check location ATC ACLD above clouds GEN ACLS automatic carrier landing system GEN ACLT accelerate GEN ACM air combat maneuvers ATC ACN aircraft classification number ICAO ACN all concerned notified GEN ACNOT accident notice GEN ACP acceptance (message type designator) ICAO ACP area command post GEN ACPT accept GEN ACPY accompany GEN ACR air carrier GEN ACRBT acrobatic ATC ACRS across GEN ACSL standing lenticular altocumulus NWS ACT active or activated or activity ICAO ACT air combat training ATC ACT Technical Center, FAA GEN ACTG acting GEN ACTV active GEN ACTVT activate GEN ACW aircraft control and warning GEN ACYC Anticyclonic NWS AD Aerodrome ICAO ADA advisory area ATC ADAP Airport Development Aid Program GEN ADC Aerodrome chart ICAO ADCF Air Defense Control Facility GEN ADCON advise or issue instructions to all concerned GEN ADCUS advise customs GEN ADDN addition GEN ADE Air Defense Emergency GEN ADF automatic direction finder GEN ADFAP automatic direction finder approach ATC ADIZ air defense identification zone GEN ADJ adjacent ICAO ADL aggregate demand list ATC ADLO Air Defense Liaison Officer GEN ADLY arrival delay ATC ADMAP advise by air mail as soon as possible GEN ADMIN administration GEN ADMIR administrator GEN ADMIS aircraft departing at (number of minutes) intervals ATC ADMIV administrative GEN ADNL additional GEN ADNL TFC additional traffic is ATC ADNOK advise if not correct ATC ADO Aerodrome office (specify service) ICAO ADO Airport District Office GEN ADP automatic data processing GEN ADPE automatic data processing equipment GEN ADPS automatic data processing systems GEN ADQT adequate GEN ADR airport departure rate ATC ADR advisory route ATC ADRDE advise reason for delay ATC ADRNDCK adirondack NWS ADRT alternate departure route ATC ADS address GEN ADS Air Defense Sector GEN ADS automatic dependent surveillance ICAO ADS-B Automatic Dependent Surveillance-B ICAO ADSPN advise disposition GEN ADSU automatic dependent surveillance unit ICAO ADV advise NWS ADVALT allotment advice GEN ADVC advice GEN ADVCTN advection NWS ADVN advance GEN ADVY advisory NWS ADVZY advisory ATC ADW air defense warning GEN ADZ advise ICAO ADZAR advise arrival ATC ADZI advise intentions ATC ADZOF advise this office GEN ADZY advisory ATC ADZY advisory GEN AEA Eastern Region, FAA GEN AEM aircraft and engine mechanic GEN AENG airways engineer GEN AER approach end runway GEN AERO aeronautical GEN AES aircraft earth station ICAO AEU Europe, Africa, and Middle East Office, FAA GEN AEVAC air evacuation ATC AEW airborne early warning GEN AFB Air Force Base GEN AFC area forecast center NWS AFCT affect GEN AFDK after dark NWS AFIL filed flight plan in the air GEN AFIO authorization for interceptor operations ATC AFIRM affirmative GEN AFIS aerodrome flight information service ICAO AFJ Air Force Jet ATC AFM affirmative ICAO AFNEA Air Force NOTAM Exchange Area GEN AFNEO Air Force NOTAM Exchange Office GEN AFOVRN Air Force overrun 1000-ft standard approach lighting system MIL AFRCC Air Force Rescue Coordination Center GEN AFREP Air Force Representative to the FAA GEN AFRT air freight GEN AFS aeronautical fixed service GEN AFT after GEN AFTN Aeronautical Fixed Telecommunications Network GEN AFTN afternoon GEN AG air ground ATC AGA aerodromes, air routes and ground aids ICAO AGACS automatic ground air/ground communication system GEN A-GEAR arresting gear GEN AGL above ground level ICAO AGL Great Lakes Region, FAA GEN AGN again GEN AGR agree GEN AGRMT agreement GEN AHD ahead GEN AI arrival approved request for IFR flight ATC AIA advise if able ATC AIATSC all international air traffic switching centers GEN AIC Aeronautical Information Circular GEN AID airport information desk GEN AIDC Air traffic services inter-facility data communication ICAO AIFP activate IFR flight plan ATC AILS automatic instrument landing system GEN AIM Airman's Information Manual GEN AIP Aeronautical Information Publication ATC AIP aeronautical information publications (In General) GEN AIRAC aeronautical information regulation and control GEN AIRCOMNET Air Force Communications Network GEN AIREP air report GEN AIRFL air refueling ATC AIRMET Airmen's Meteorological Information GEN AIROPNET air operations network GEN AIS aeronautical information service GEN AIS aeronautical information specialist GEN AIS airport in sight GEN AL all (when used as prefix) GEN AL annual leave GEN AL/(---) at least (altitude) ATC ALA alighting area GEN ALACFO all air carrier field offices GEN ALADLO all air defense liaison officers in service area GEN ALAFFO all technical operations GEN ALANO all accident notice offices GEN ALARTC all air route traffic control centers in service area GEN ALAT all air traffic service personnel in service area GEN ALATAS all air traffic (area) supervisors in service area GEN ALATF all air traffic field facilities GEN ALATFO all air traffic field offices GEN ALCKT all offices having send-receive teletypewriter service on circuit GEN ALCS/C all air traffic combined station/centers in service area GEN ALCS/T All air traffic combined station/towers in service area GEN ALCT attempt to locate GEN ALDA Air Line Dispatchers Association GEN ALERFA alert phase code (alerting service) ATC ALF aloft NWS ALFAA all FAA field offices and personnel GEN ALFAB all FAA offices on NADIN GEN ALFSFO all flight standards field offices GEN ALFSS all flight service stations in service area GEN ALG along GEN ALGHNY Allegheny NWS ALIATSC all international aeronautical telecommunication switching centers GEN ALIFO all international field offices GEN ALIFSS all international flight service stations in service area GEN ALNMT alignment GEN ALNOT alert notice GEN ALP airport layout plan GEN ALPA Air Line Pilots Association GEN ALQDS all quadrants NWS ALR alerting ICAO ALRAFAC all radar ATC facilities in service area GEN ALRGN all regional/service area offices GEN ALS approach light system ICAO ALSEC all sectors NWS ALSF-1 standard 2400' high-intensity approach lighting system with sequenced flashers (Category I configuration) GEN ALSF-2 standard 2400' high-intensity approach lighting system with sequenced flashers (Category II configuration) GEN ALSTG altimeter setting GEN ALT altitude ICAO ALTA Alberta NWS ALTM altimeter GEN ALTN alternate or alternating ICAO ALTN alternate (aerodrome) ICAO ALTPT alternate airport GEN ALTRV altitude reservation GEN ALTWR all ATC towers in service area GEN ALUTN Aleutian NWS ALWF actual wind factor NWS AM ante meridiem NWS AMA area minimum altitude ICAO AMB ambiguity GEN AMC Air Mobility Command ATC AMC Mike Monroney Aeronautical Center, FAA GEN AMCL amended clearance ATC AMD amend / amended forecast GEN/ AMDT amendment ICAO AMECH account mechanical GEN AMGR airport manager GEN AMIS aircraft movement information services GEN AMOS Automatic Meteorological Observing System GEN AMP Amplifier or amplify GEN AMPLTD amplitude NWS AMRF amended route of flight ATC AMS aeronautical mobile service GEN AMS air mass NWS AMS American Meteorological Society NWS AMSL above mean sea level GEN AMSS aeronautical mobile satellite service ICAO AMT Amount GEN AMVER Automated Mutual-Assistance Vessel Rescue System ATC ANC Aeronautical chart 1:500 000 (followed by name/title) ICAO ANCPT anticipate GEN ANCS Aeronautical navigation chart small scale (followed by name/title scale) ICAO ANE New England Region, FAA GEN ANF air navigation facility GEN ANG Air National Guard GEN ANLYS Analysis NWS ANM Northwest Mountain Region, FAA GEN ANMS Automatic Network Management System GEN ANNC announce GEN ANR Advanced Navigation Routes ATC ANRA air navigation radio aids GEN ANS answer GEN ANT antenna GEN AO1 ASOS automated observation without precipitation discriminator (rain/snow) METAR AO2 ASOS automated observation with precipitation discriminator (rain/snow) NWS AOA at or above ATC AOAF at or after ATC AOB at or below ATC AOBF at or before ATC AOC aerodrome obstacle chart (followed by type & name/title) ICAO AOC airport operating certificate GEN AOCP aircraft out of commission for parts GEN AOE airport of entry GEN AOPA Aircraft Owners and Pilots Association GEN AP airport ICAO AP anomalous propagation ATC APAP approach path alignment panel GEN APAPI Abbreviated precision approach path indicator ICAO APC area positive control ATC APCH approach ICAO APDC Aircraft parking/docking chart (followed by name/title) ICAO APL airport lights GEN APLCN Appalachian NWS APN Apron ICAO APNT appoint GEN APP approach control or approach control office ICAO APPA advise present position and altitude ATC APPR appear GEN APR airports program report GEN APREQ approval request GEN APRNT apparent GEN APROP appropriate GEN APRX approximate GEN APS airborne pulse search radar GEN APSG after passing ICAO APV approve GEN APVL approval GEN AR Atlantic Route ATC ARAC area airports checked ATC ARAC Army Radar Approach Control facility (US Army) GEN ARAD altitude radial ATC ARB Air Reserve Base GEN ARC Area chart ICAO ARCP air refueling control point ATC AREP air refueling egress point ATC AREX air refueling exit ATC ARFF aircraft rescue and fire fighting ATC ARFFOK airport rescue and fire fighting alarm checked ATC ARFOR area forecast GEN ARINC Aeronautical Radio, Incorporated GEN ARIP air refueling initial point ATC ARL Aerial ATC ARLO Army Liaison Officer GEN ARMET forecast upper wind and temperature at specified points GEN ARML Airmail GEN ARND Around GEN ARNG Arrange GEN ARNOT area notice GEN ARO air traffic services reporting office GEN ARO Airport Reservations Office GEN ARP aerodrome reference point ICAO ARP airport reference point GEN ARP airport reservation position GEN ARP air-report GEN ARPT Airport GEN ARQ automatic error correction equipment GEN ARR arrive or arrival ICAO ARS Air Rescue Service (USAF) GEN ARS special air-report GEN ARSA airport radar service area ATC ARSR air route surveillance radar GEN ARST arrest GEN ARST arresting ICAO ARTC air route traffic control GEN ARTCC Air Route Traffic Control Center GEN ARTS Automated Radar Terminal Systems GEN ARU Airborne Radar Unit GEN ARU Airspace Reservation Unit (Canadian) GEN ARUNK arrival unknown ATC AS altostratus NWS AS/R automatic send/receive GEN ASAP as soon as possible GEN ASC ascent to GEN ASCU automatic scanning control unit GEN ASD airspace docket GEN ASDA accelerate-stop distance available ICAO ASDE airport surface detection equipment GEN ASE Altimetry system error ICAO ASGN assign GEN ASHTAM Volcanic Ash Advisory ICAO ASI altimeter setting indicator GEN ASIP airspace flight inspection pilot GEN ASL above sea level GEN ASMD assumed ATC ASND ascend GEN ASO Southern Region, FAA GEN ASOS automated surface observing system NWS ASP airport system plan GEN ASP airspace GEN ASPH asphalt ICAO ASR airport surveillance radar GEN ASSOC associate GEN ASST assistant GEN ASW Southwest Region, FAA GEN ATA actual time of arrival ATC ATA Air Transport Association of America GEN ATAM at and maintain ATC ATAR above transmitted as received GEN ATC air traffic control ICAO ATCA Air Traffic Control Association GEN ATCA ATC advises ATC ATCAA ATC assigned airspace ATC ATCBI ATC beacon interrogator GEN ATCC ATC clears ATC ATCF ATC facility GEN ATCH attach GEN ATCOR ATC operations representative GEN ATCR ATC requests ATC ATCRBS ATC radar beacon system GEN ATCS ATC specialist GEN ATCSCC David J. Hurley ATC System Command Center GEN ATCT Airport Traffic Control Tower GEN ATD actual time of departure ATC ATFC account traffic GEN ATFM air traffic flow management ICAO ATIS automatic terminal information service ICAO ATLC Atlantic NWS ATM air traffic management ICAO ATM air traffic manager ATC ATM authentication maneuver ATC ATMT attempt GEN ATMTC attempt to contact ATC ATN Aeronautical Telecommunications Network ICAO ATND attend GEN ATO aeronautical telecommunications operator GEN ATO Air Traffic Organization GEN ATOG allowable take-off gross weight GEN ATP actual time of penetration ATC ATP air traffic procedures GEN ATPAC Air Traffic Procedures Advisory Committee GEN ATR air transport rating GEN ATREP air traffic representative GEN ATRLS actual time of release ATC ATSCCP Air Traffic Service Contingency Command Post GEN ATT American Telephone and Telegraph Company GEN ATTM at this time GEN ATTN attention GEN AT-VASIS Abbreviated T visual approach slope indicator system ICAO ATZ aerodrome traffic zone ICAO AUGRA authority granted GEN AURBO Aurora Borealis NWS AUREQ authority is requested GEN AUTH authority GEN AUTH authorized or authorization ICAO AUTO automatic ICAO AUTOB automatic weather reporting system GEN AUW all up weight (gross weight) GEN AUX auxiliary GEN AUZ authorize GEN AVANA altitude reservation void for aircraft not airborne by --- ATC AVBL available or availability ICAO AVFP activate VFR flight plan ATC AVFPNO pilot failed to activate VFR/DVFR flight plan ATC AVG average GEN AVGAS aviation gasoline ICAO AVN aviation GEN AWA advise when able ATC AWANS Aviation Weather and NOTAM System GEN AWBE automatic weather broadcast equipment GEN AWE advise when established ATC AWL all weather landing ATC AWOS automatic weather observing/reporting system GEN AWP aviation weather processors NWS AWP Western-Pacific Region, FAA GEN AWS air weather service (USAF) GEN AWT await or awaiting GEN AWX account weather GEN AWY airway ICAO AXPS air express GEN AZM azimuth ICAO AZRAN azimuth and range data ATC , BContraction Definition Usage B base leg ATC B beginning of precipitation (time in minutes) (weather reports only) NWS B Bering Standard Time (time groups only) NWS B blue GEN B center clearance delivered ATC BA braking action freezing rain information not available (weather reports only) |
