FAA Contractions and Abbreviations Guide - FLY8MA Online Flight Training

FAA Aviation Contractions and Abbreviations

Here you can find every known contraction used by the FAA and other government agencies in regards to aviation abbreviations. Use the “cntrl+F” function to find or search the document.

This guide combines FAA, NOAA, ATC, and many other guides for both VFR and IFR flying.

Contraction	Definition	Usage	Contraction	Definition	Usage
Plus FC	Tornado/waterspout	METAR	M	Mach number	GEN
A	absoloute	NWS	M	maritime (air mass)	NWS
A	Alaskan Standard Time (time groups only)	NWS	M	metres (preceded by figures)	ICAO
A	Amber	GEN	M	missing (weather reports only)	NWS
A	Arctic (air mass)	NWS	M	Mountain Standard Time (time groups only)	NWS
A/A	air to air	ATC	MA	map analysis	NWS
AAF	Army Air Field	PHAK	MAA	maximum authorized (IFR) altitude	GEN
AAI	arival aircrat interval	PHAK	MAC	Military Airlift Command	GEN
ABDIS	automated data interchange system service B	PHAK	MACH	MACH Number (speed ratio to speed of sound)	ATC
A/C	appraoch control	ATC	MAHWP	Missed Approach Holding Waypoint	AIM
A/C	aircraft	PHAK	MACKAY	Mackay Radio and Telegraph Company	GEN
A/G	air to ground	ICAO	MACVFR	make altitude changes VFR	ATC
A/H	already had	ATC	MAFAP	minimum altitude over facility on final approach course	ATC
AAC	Alaskan Air Command	GEN	MAG	magnetic	GEN
AAD	Assigned altitude deviation	ICAO	MAGSI	minimum altitude at glide slope intersection inbound	GEN
AADC	approach and departure control	ATC	MAINT	maintenance	ICAO
AAF	Army Air Field	GEN	MAL	maintain at least (altitude)	ATC
AAITVL	arrival aircraft interval	ATC	MALS	medium intensity approach lighting system	GEN
AAL	Above aerodrome level	ICAO	MALSF	medium intensity approach lighting system with sequenced flashers	GEN
AAP	advise if able to proceed	ATC	MALSR	medium intensity approach lighting system with runway alignment indicator lights	GEN
AAP	Advanced automation program	PHAK	MAM	maintenance assumes monitor	GEN
AAR	airport arrival rate	ATC	MAN	Manitoba	NWS
AARTE	airport acceptance rate	ATC	MAN	manual	GEN
AATM	at all times	GEN	MANAM	manual amendment	GEN
AAWF	Auxiliary Aviation Weather Facility	NWS	MANOP	manual of operations	GEN
AAWTA	Advise at what time able	ICAO	MAP	aeronautical maps and charts	ICAO
AAWU	Alaskan Aviation Weather Unit	AIM	MAP	missed approach point	GEN
AAS	airport advisory service		MAPS	Meteorological Aeronautical Presentation System	GEN
AB	Airborne	ATC	MAPT	missed approach point	ICAO
ABBR	abbriviate	GEN	MAR	at sea	ICAO
ABCST	automatic broadcast	GEN	MARPT	municipal airport	GEN
ABD	aboard	GEN	MARSA	military assumes responsibility for separation of aircraft	GEN
ABI	advance boundry information	ICAO	MAS	manual A1 simplex	ICAO
ABLCHG	Airborne Launching	ATC	MAS	military alert system	GEN
ABM	abeam	ICAO	MAWP	Missed Approach Waypoint	AIM
ABN	aerodrome beacon	ICAO	MAX	maximum	GEN
ABND	abandon	GEN	MB	marker beacon	GEN
ABNDT	abundant	GEN	MB	millibars	GEN
ABNML	abnormal	GEN	MB	Magnetic bearing
ABT	about	GEN	Mbps	megabits per second	PHAK
ABV	Above aerodrome level	ICAO	MBST	microburst	ICAO
ABV	Above	NOTAM	MCA	minimum crossing altitude	ICAO
AC	Advisory Circular	GEN	MCAS	Marine Corps Air Station	GEN
AC	altocumulus	NWS	MCAS(H)	Marine Corps Air Station (Helicopter)	GEN
AC	assistant chief	GEN	MCC	maintiance control system	PHAK
ACA	arctic control area	ATC	MCK	maintenance check	GEN
ACAR	aircraft communications addressing and reporting systems	AIM	MCL	middle compass locator	PHAK
ACARS	Aircraft communication addressing and reporting system	ICAO	MCS	Master Control Station	ATC
ACAIS	air carrier activity information system	PHAK	MCW	modulated continuous wave	ICAO
ACAS	airborne collision avoidance system	ICAO	MCZNE	minimum when control zone effective	GEN
ACC	area control center	ATC	MDA	minimum descent altitude	ICAO
ACC	altocumulus castellaus	NWS	MDF	medium frequency direction finding station	ICAO
ACCID	notification of aircraft accident	ATC	MDFR	make descent from	ATC
ACCT	account	GEN	MDFY	modify	GEN
ACCID	accumulate	GEN	MDH	minimum descent height	ICAO
ACCT	accident	GEN	MDT	moderate	GEN
ACCT	accounting records	PHAK	MDZ	modernize	GEN
ACCUM	accumulate	GEN	MDZN	modernization	GEN
ACDNT	accident	GEN	MEA	minimum en route altitude	ICAO
ACD	Automatic Call Distributor	PHAK	MEARTS	. Micro En Route Automated Radar Tracking System
ACDO	Air Carrier District Office	GEN	MECH	mechanic	GEN
ACE	Central Region, FAA	GEN	MED	medical	GEN
ACF	Area Control Facility	PHAK	MED	medium	GEN
ACES	access	GEN	MEDEVAC	medical emergency evacuation	ICAO
ACFT	Aircraft	ICAO	MEGG	merging	NWS
ACFO	Area Control Facility	PHAK	MEHT	minimum eye height over threshold	ICAO
ACID	aircraft identification	ATC	MEL	minimum equiptment list
ACK	ackowledge	GEN	MEML	memorial	GEN
ACL	altimeter check location	ATC	MET	meteorological	GEN
ACLD	above clouds	GEN	METAR	aviation routine weather report	ICAO
ACLS	automatic carrier landing system	GEN	METI	meterorological information	PHAK
ACLT	accelerate	GEN	METOF	meteorological officer	GEN
ACM	air combat manuvers	ATC	METRO	metropolitan	GEN
ACN	aircraft classification number	ICAO	MEX	Mexico	NWS
ACN	all concerns notified	GEN	MF	medium frequency	GEN
ACNOT	accident notice	GEN	MFJ	modified final judgement	PHAK
ACP	acceptance (message type designator)	ICAO	MFL	maintain flight level	ATC
ACP	area command post	GEN	MFOB	minimum fuel on board	ATC
ACPT	accept	GEN	MFPOF	master flight plan on file	ATC
ACPY	accompany	GEN	MFS	military flight service	GEN
ACR	air carrier	GEN	MFT	meter fix crossing time/slot time	PHAK
ACRBT	aerobatic	ATC	MFV	forward visibility more than (miles)	ATC
ACRS	across	GEN	MFXT	meter fix time	ATC
ACSL	standing lenticular altocumulous	NWS	MGAT	make good a track of (degrees)	ATC
ACT	active or activated or activity	ICAO	MGMT	make good a magnetic track of (degrees)	ATC
ACT	air combat training	ATC	MGMT	management	GEN
ACT	Technical Center, FAA	GEN	MGR	manager	GEN
ACTG	acting	GEN	MH	Magnetic heading
ACTV	active	GEN	MHA	minimum holding altitude	GEN
ACTVT	activate	GEN	MHDF	medium and high frequency direction-finding station (same location)	ICAO
ACO	Office of Airports Compliance and Field Operations; Aircraft Certification Office	PHAK	MHDG	magnetic heading	GEN
ACR	air carrier	PHAK	MHFR	military height finder radar	GEN
ACRP	Airport Cooperative Research Program	PHAK	Hhg	Meghertz	PHAK
ACS	Airman Certification Standard	PHAK	MHKVLY	Mohawk Valley	NWS
ACT	active, activated, or activity	PHAK	MHVDF	medium high and very high frequency direction-finding station (same location)	ICAO
ACW	aircraft control warning	GEN	MHZ	megahertz	ICAO
ACYC	anticyclonic	NWS	MI	manufacturing inspector	GEN
AD	aerodrome	ICAO	MI	mile	GEN
ADA	advisory area	ATC	MI	shallow	METAR
ADA	air defense area	PHAK	MIA	minimum IFR altitudes	PHAK
ADAP	Airport Development Aid Program	GEN	MID	middle	GEN
ADAS	AWOS data acquisition system	PHAK	MID	mid-point (related to RVR)	ICAO
ADC	Aerodrome Chart	ICAO	MID/ASIA	ICAO Middle East/Asia Region	ATC
ADCCP	advanced data communications control procedure	PHAK	MIDIZ	Mid-Canada Identification Zone	GEN
ADCF	Air Defense Control Facility	GEN	MIDN	midnight	NWS
ADCON	advise ot issue instructions to all concerned	GEN	MIDO	manufacturing inspection district office	PHAK
ADCUS	advise customs	GEN	MIDPT	midpoint	GEN
ADDA	administrative data	PHAK	MIFG	patches of shallow fog not deeper than two meters	NWS
ADDS	Aviation digital data service	PHAK	MIFG	shallow fog	METAR
ADDN	addition	GEN	MIJI	meaconing, intrusion, jamming, interference	ATC
ADE	Air Defense Emergency	GEN	MIL	military	ICAO
ADF	automatic direction finder	GEN	MIMNO	mimeographic notice	GEN
ADFAP	automatic direction finder appraoch	ATC	MIN	minute	ICAO
ADI	automatic de-ice and inhibitor	PHAK	MINIT	minutes in trail	ATC
ADIN	AUTODIN service	PHAK	MIREQ	minimum requirements specified	GEN
ADIZ	air defense identification zone	GEN	MIRL	medium intensity runway edge lights	GEN
ADJ	adjacent	ICAO	MIS	Missing (transmission identification)	ICAO
ADL	aggregate demand list	ATC	MISC	miscellaneous	GEN
ADLO	Air Defence Liason Officer	GEN	MISG	missing	GEN
ADLY	Arrival Delay	ATC	MISL	missile	GEN
ADMAP	advise by air mail as a soon as possible	GEN	MISO	maufacturing inspection district office	PHAK
ADMIN	administration	GEN	MIT	miles in trail	ATC
ADMIR	administrator	GEN	MITO	minimum interval take-off	ATC
ADMIS	aircraft departing at(number of minutes) intervals	ATC	MITRE	mitre corperation	PHAK
ADMIV	administrative	GEN	MKCT	make check turn	ATC
ADNL TFC	additional traffic is	ATC	MKD	marked	GEN
ADNOK	advise if not correct	ATC	MKR	marker	GEN
ADO	Aerdrome office (specific service)	ICAO	MKR	marker radio beacon	ICAO
ADO	Airport District Office	GEN	MLS	microwave landing system	GEN
ADP	automatic data processing	GEN	MLTLVL	melting level	NWS
ADPE	automatic data processing equiptment	GEN	MM	middle marker	ICAO
ADPS	automatic processing systems	GEN	MM	millimeter	GEN
ADQT	adequate	GEN	MMAC	mike monroney aeronautical center	PHAK
ADR	airport departure rate	ATC	MMACH	maintain Mach	ATC
ADR	advistory route	ATC	MMC	maintinance monitoring control	PHAK
ADRDE	advise reason for delay	ATC	MMO	main meteorological office	NWS
ADRNDCK	adirondak	NWS	MMS	maintence monitoring system	PHAK
ADRT	alternate departure route	ATC	MNLD	mainland	NWS
ADS	address	GEN	MNLY	mainly	GEN
ADS	Air Defense Sector	GEN	MNM	minimum	ICAO
ADS	automatic dependent surveillance	ICAO	MNPS	minimum navigation performance specification	ATC
ADS-B	Automatic Dependent surveillance- Broadcast	ICAO	MNPSA	minimum navigation performance specification airspace	ATC
ADSIM	airfield delay simulation model	PHAK	MNT	monitor, monitored, or monitoring	ICAO
ADSPN	advise disposition	GEN	MNTN	maintain	ICAO
ADSU	automatic dependent surveillance unit	ICAO	MNVR	maneuver	GEN
ADSY	administrative equipment systems	PHAK	MOA	memorandum of agreement	GEN
ADTN	Administrative Data Transmission Network	PHAK	MOA	military operations area	ICAO
ADTN2000	Administrative Data Transmission Network 2000	PHAK	MOC	minimum obstacle clearance (required)	ICAO
ADV	advise	NWS	MOCA	minimum obstruction clearance altitude	ICAO
ADVALT	allotment advice	GEN	MOD	moderate	GEN
ADVC	advice	GEN	MOD	modulate or modulation or modulator	GEN
ADVCTN	advection	NWS	MODE C	altitude-encoded beacon reply alititude reporting mode of secondary radar	PHAK
ADVN	advance	GEN	MODE S	mode select beacon system	PHAK
ADVO	administrative voice	PHAK	MOGR	moderate or greater	NWS
ADVY	advisory	NWS	MON	above mountains	ICAO
ADVZY	advistory	ATC	MON	Monday	ICAO
ADW	air defense warning	GEN	MONOK	monitor resumed normal operation	GEN
ADZ	advise	ICAO	MONOS	monitor out of service	GEN
ADZAR	advise arrival	ATC	MONTR	monitor	NWS
ADZD	advised	PHAK	MOPS	Minimum operational performance standards	ICAO
ADZI	advise intentions	ATC	MOPTAR	multi-object phase tracking and ranging	GEN
ADZOF	advise this office	GEN	MOREPS	monitor station reports	GEN
ADZY	advisory	ATC	MOT	Ministry of Transport (Canada)	GEN
ADZY	advistory	GEN	MOTNE	Meteorological Operational Telecommunications Network Europe	ICAO
AEA	Eastern Region, FAA	GEN	MOV	Move, or moving, or movement	ICAO
AEG	Aircraft Evaluation Group	PHAK	MOU	memorandum of understanding	PHAK
AEM	aircraft and engine mechanic	GEN	MPH	miles per hour	GEN
AENG	airways engineer	GEN	MPO	metropolitan planning organization	PHAK
AER	approach end runway	GEN	MPP	Merit Promotion Program	GEN
AERA	automated en route air traffic control	PHAK	MPS	meters per second	ICAO
AERO	aeronautical	GEN	MPVA	maintain a position VFR and advise	ATC
AES	aircraft earth station	ICAO	MRA	minimum reception altitude	GEN
AEU	Europe, Africa, and Middle East Office, FAA	GEN	MRB	Magnetic Reference Bearing	AIM
AEVAC	air evacuation	ATC	MRC	Monthly recurring charge	PHAK
AEW	airborne early warning	AEW	MRG	medium range	GEN
AEX	automated execution	PHAK	MRGL	marginal	NWS
AF	airway facilities	PHAK	MRM	maintenance returns monitor	GEN
AFB	Air Force Base	GEN	MRNG	morning	NWS
AFC	area forcast center	NWS	MRP	ATS/MET reporting point	ICAO
AFCS	automatic flight control systen	AIM	MRR	mechanical reliability report	GEN
AFCT	affect	GEN	MRTM	maritime	NWS
AFDK	after dark	NWS	MRU	Military Radar Unit	GEN
AFIL	filed flight plan in the air	GEN	MS	minus	NWS
AFIO	authorization for interceptor operations	ATC	MSA	minimum safe/sector altitude	GEN
AFIRM	affirmative	GEN	MSAW	minimum safe altitude warning	GEN
AFIS	aerodrome flight information service	ICAO	MSG	message	ICAO
AFJ	Air Force Jet	ATC	MSGCTR	message center	GEN
AFM	affirmative	ICAO	MSL	mean sea level	ICAO
AFM	Airplane Flight Manual	PHAK	MSN	message switching network	PHAK
AFNEA	Air Force NOTAM Exchange area	GEN	MSR	Message (transmission identification) has been misrouted	ICAO
AFNEO	Air Force NOTAM Exchange Office	GEN	MSSR	Monopulse secondary surveillance radar	ICAO
AFOVRN	Air Force overron 1000-ft standard approach lighting system	MIL	MSTLY	mostly	NWS
AFP	area flight plan	PHAK	MSTR	moisture	NWS
AFRCC	Air Force Rescue Coordination Center	GEN	MT	mountain	ICAO
AFREP	Air Force Representative to the FAA	GEN	MTCA	minimum terrain clearance altitude	GEN
AFRT	air freight	GEN	MTCS	modular termical comminications system	PHAK
AFS	aeronautical fixed service	GEN	MTI	moving target indicator	ATC
AFSFO	AFS field office		MTN	mountain	NWS
AFSFU	AFS field unit		MTOS	Mountain Obscuration	AIM
AFSOU	AFS field office unit (standard is AFSFOU		MTR	military training route	GEN
AFSS	Automated Flight Service Station	GEN	MTRL	material	GEN
AFT	after	GEN	MTRY	momentary	GEN
AFTN	Aeronautical Fixed Telecommunications Network	GEN	MTU	metric units	ICAO
AFTN	afternoon	GEN	MTW	mountain wave	ICAO
AG	air ground	ATC	MU	designate a friction value representing runway surface conditions (Greek letter)	GEN
AGA	aerodromes, air routes and ground aids	ICAO	MUA	maximum usable altitude	GEN
AGACS	automatic ground air/ground comminication system	GEN	MUD	mud	PHAK
A-GEAR	arresting gear	GEN	MUF	maximum usable frequency	GEN
AGIS	airports geographic information system		MULT	multiple	GEN
AGL	above ground level	ICAO	MUNI	municipal	GEN
AGL	Great Lakes Region, FAA	GEN	MUX	multiplexor	PHAK
AGN	again	GEN	MV	millivolt	GEN
AGR	agree	GEN	MVA	minimum vector altitude	GEN
AGRMT	agreement	GEN	MVDF	medium and very high frequency direction-finding station (same location)	ICAO
A/HA	Altitude/ Height	PHAK	MVFR	maintain VFR	ATC
AHD	ahead	GEN	MVFR	marginal VFR	NWS
AI	arrival approved request for IFR flight	ATC	MVSP	maintain visual separation	ATC
AHRS	Attitude heading reference system		MWA	Mountain Wave Activity	AIM
AIA	advise is able	ATC	MWO	Meteorological Watch Office	ICAO
AIATSC	all of the international air traffic switching centers	GEN	MWRC	maintain well to right of course	ATC
AIC	Aeronautical Information Circular	GEN	MWTCS	modernized weather teletypewriter communications system	GEN
AID	airport information desk	GEN	MXD	mixed	NWS
AIDC	Air traffic services inter-facility data communication	ICAO	N	north or northern latitude	ICAO
AIFP	activate IFR flight plan	ATC	N/A	not applicable	GEN
AILS	automatic instruments landing system	GEN	NA	not authorized	GEN
AIM	Airman’s Information Manual	GEN	NAS	National Airspace System	AIM
AIP	Aeronautical Information publications	ATC	NAAS	Naval Auxiliary Air Station	GEN
AIP	Aeronautical Information publications (in general)	GEN	NAATS	National Association of Air Traffic Control Specialists	GEN
AIRAC	aeronautical information regulation and control	GEN	NAAQS	National Airspace Data Interchange Network	PHAK
AIRCOMNET	Air Force Communications Network	GEN	NAB	not above	GEN
AIREP	air report	GEN	NACOS	national communications schedule	GEN
AIRFL	air refueling	ATC	NADA	ADIN concentrator	PHAK
AIRMET	Airmen’s Meteorological Information	GEN	NADIN	National Airspace Data Interchange Network	GEN
AIRNET	Airport Network Simulation Model	PHAK	NADSW	NADIN switches	PHAK
AIROPNET	air operations network	GEN	NAF	Naval Air Facility	GEN
AIS	aeronautical information service	GEN	NAFEC	National Aviation Facilities Experimental Center	GEN
AIS	aeronautical information specialist	GEN	NAILS	national airspace data interchange network	PHAK
AIS	airport in sighn	GEN	NAMS	NADIN IA	PHAK
AIT	automated information transfer	PHAK	NANAC	National Aircraft Noise Abatement Council	GEN
AL	all(when used as prefix)	GEN	NAP	not at present	GEN
AL	annual leave	GEN	NAPRS	National Airspace Performance Reporting System	ATC
AL/(—_	at least (altitude)	ATC	NAR	North American Route	GEN
ALA	alighting area	GEN	NAR	not according to routine	GEN
ALACFO	all air carrier feild offices	GEN	NAS	National Airspace System	GEN
ALADLO	all air defense liaison officers in service area	GEN	NAS	Naval Air Station	GEN
ALAFFO	all technical operations	GEN	NASA	National Aeronautics and Space Administration	ICAO
ALARTC	all air route traffic contril centers in service areas	GEN	NASC	National AIS system centre	ICAO
ALAT	all air traffic service personnel in service area	GEN	NASDC	national aviation saftey data	PHAK
ALATAS	all air traffic (area) supervisors in service area	GEN	NASEO	National Airways System Engineering office	GEN
ALATF	all air traffic field facilities	GEN	NASP	National Airport System Plan	GEN
ALATFO	all air traffic field offices	GEN	NASPAC	national airspace system performance analysis capability	PHAK
ALCKT	all offices having send-receive tele-typwriter service on circuit	GEN	NAT	North Atlantic	GEN
ALCS/C	all air traffic combined station/centers in service area	GEN	NAT	not ARTS tracked	ATC
ALCS/T	all air traffic combined station/towers in service area	GEN	NATCA	National Air Traffic Controllers Association	ATC
ALCT	attempt to locate	GEN	NATCAS	Navigation, ATC, and Collision Avoidance System	GEN
ALD	Available landing distance	AIM	NATCC	National Air Transport Coordinating Committee	GEN
ALDA	Air Line Dispatchers Association	GEN	NATCO	national communications switching center	PHAK
ALDARS	automated lighting detection and reporting system	AIM	NATCOM	National Communications Center	GEN
ALERFA	alert phase code (alerting service)	ATC	NATL	national	GEN
ALF	aloft	NWS	NATR	no additional traffic reported	ATC
ALFAA	all FAA field offices and personnel	GEN	NATS	noise abatement test system	GEN
ALFAB	all FAA offices on NADIN	GEN	NAV	navigation	ICAO
ALFSFO	all flight standards field offices	GEN	NAVAID	navigational aid	GEN
ALFSS	all flight service stations in service area	GEN	NAVCEN	Coast Guard Navigation Center	AIM
ALG	along	GEN	NAVLO	Navy Liaison Officer	GEN
ALGHNY	allegheny	NWS	NAVMN	navigation monitor and control	PHAK
ALIATSC	all international aeronautical tele-communication switching centers	GEN	NAVREP	Navy Representative to the FAA	GEN
ALIFO	all international field offices	GEN	NAWAU	national aviation weather advisory unit	PHAK
ALIFSS	all international flight service stations in service area	GEN	NAWPF	National aviation weather processing facilitu	PHAK
ALMNT	alignment	GEN	NB	New Brunswick	NWS
ALNOT	alert notice	GEN	NB	northbound	ICAO
ALP	airport layout notice	GEN	NBCAP	national beacon code allocation plan	GEN
ALPA	Air Line Pilots Association	GEN	NBFR	not before	ICAO
ALQDA	all quadrants	NWS	NBND	northbound	GEN
ALR	alerting	ICAO	NBRHD	neighborhood	GEN
ALRAFAC	all rader ATC facilities in service area	GEN	NC	no change	GEN
ALRGN	all regional/service area offices	GEN	NCAR	National center for atomsopheric research boulder co	PHAK
ALS	approach light system	ICAO	NCDC	National Climatic Data Center	GEN
ALSEC	all sectors	NWS	NCE	no change in estimates	ATC
ALSF	approach lights system with sequenced flashing lights		NCF	national control facility	PHAK
ALSF-1	standard 2400′ high-intensity approach lighting system with sequenced flashers (category 1 configuration)	GEN	NCIU	NEXRAD Communications interface unit	PHAK
ALSF-2	standard 2400′ high-intensity approach lighting system with sequenced flashers (category 2 configuration)	GEN	NCP	noise compatibility program	PHAK
ALSTG	altimeter setting	GEN	NCS	National Communications System	GEN
ALT	altitude	ICAO	NCWF	National Convective Weather Forecast	AIM
ALTA	Alberta	NWS	NCWX	no change in weather	NWS
ALTM	altimeter	GEN	NDB	nondirectional radio beacon	ICAO
ALTN	alternate or alternating	ICAO	NDNB	NADIN II	PHAK
ALTN	alternate (aerodrome)	ICAO	NDB/DME	NDB and DME (collocated)	GEN
ALTNLY	alternately	PHAK	NDBLO	not to descend below	ATC
ALTPT	alternate airport	GEN	NE	north-east	ICAO
ALTRV	altitude reservation	GEN	NEB	north-eastbound	ICAO
ALTWR	all ATC towers in service area	NWS	NEC	necessary	GEN
ALUTN	Aleutian	NWS	NEF	no further clearance required	ATC
ALWF	actual wind factor	NWS	NEG	negative	GEN
AM	ante meridiem	NWS	NELY	northeasterly (weather reports only)	NWS
AMA	area minimum altitude	ICAO	NEM	noise exposure map	PHAK
AMASS	airport movement area safety system	PHAK	NEPA	National environmental policy act	PHAK
AMB	ambiguity	GEN	NERN	northeastern	NWS
AMC	Air Mobility Command	ATC	NESS	national environmental satellite service	GEN
AMC	Mike Monroney Aeronautical Center. FAA	GEN	NETR	no essential traffic reported	ATC
AMCC	ADF/ARTCC Maintenance Control Center	PHAK	NEW ENG	New England	NWS
AMCL	amended clearance	ATC	NEXRAD	Next Generation Weather Radar	AIM
AMD	amend/ amended forecast	GEN	NFAX	national facimile service	PHAK
AMDT	amendment	ICAO	NFDC	National Flight Data Center	GEN
AMECH	account mechanical	GEN	NFDD	National Flight Data Digest	GEN
AMGR	airport manager	GEN	NFIS	NAS facilities information system	PHAK
AMIS	aircraft movement information services	GEN	NFLD	Newfoundland	NWS
AMOS	automatic Meteorological Observing System	GEN	NFQ	night frequency	GEN
AMP	Amplifier or Amplify	GEN	NFT	no filing time	GEN
AMPLTD	amplitude	NWS	NFU	not for us	GEN
AMRF	amend route of flight	ATC	NGA	National Geospatial−Intelligence Agency	AIM
AMS	aeronautical mobile service	GEN	NG	National Guard	GEN
AMS	air mass	NWS	NGT	night	ICAO
AMS	American Meteorological Society	NWS	NHD	not heard	ATC
AMSL	above mean sea level	GEN	NICS	National Airspace System Interfacility Communications System	GEN
AMSS	aeronautical mobile satellite service	ICAO	NIL	none	GEN
AMT	amount	GEN	NIL	unable to transmit	GEN
AMVER	Automated Mutual-Assistance Vessel Rescue System	ATC	NIS	not in system	GEN
ANC	Aeronautical Chart 1:500 000 (followed by name/title)	ICAO	NL	no layers	NWS
ANCA	Airport Noise and Capacity Act	PHAK	NLT	not later than	GEN
ANCPT	anticipate	GEN	NM	nautical mile	ICAO
ANCS	aeronautical navigation chart small scale (followed by name/title scale)	ICAO	NMAC	Near Midair Collision	AIM
ANE	New England Region, FAA	GEN	NMBR	number	NWS
ANF	air navigation facility	GEN	NMC	National Meteorological Center	GEN
ANG	Air National Gaurd	GEN	NMCE	Network monitioring and control equiptment	PHAK
ANGB	Air national gaurd base	PHAK	NMCS	network monitoring and control systems	PHAK
ANLYS	Analysis	NWS	NML	normal	GEN
ANM	Northwest Mountain Region, FAA	GEN	NMN	no middle name	GEN
ANMS	Automatic Network Managment Systems	GEN	NMR	nautical mile radius	GEN
ANNC	announce	GEN	NMRS	numerous	GEN
ANP	Actual navigation performance	AIM	NNE	north-north east	ICAO
ANR	Advanced Navigation Routes	ATC	NNERN	north-northeastern (weather reports only)	NWS
ANRA	air navigation radio aids	GEN	NNEWD	north-northeastward (weather reports only)	NWS
ANS	answer	GEN	NNW	north-north west	ICAO
ANSI	American National Standards Group	PHAK	NNWRN	north-northwestern (weather reports only)	NWS
ANT	antenne	GEN	NNWWD	north-westward (weather reports only)	NWS
AO1	ASOS automated observation without preipitation discriminator (rain/snow)	METAR	NO	No (negative)	ICAO
AO2	ASOS automated observation with preipitation discriminator (rain/snow)	NWS	NO	not available	METAR
AOA	at or above	ATC	NOAA	National Oceanic and Atmospheric Administration	GEN
AOAF	at or after	ATC	NOAC	no action necessary	GEN
AOB	at or below	ATC	NOC	notice of completion	PHAK
AOBF	at or before	ATC	NOF	NOTAM Office	GEN
AOC	aerodrome obstacle chart (followed by type & name/title)	ICAO	NOFIN	no further information	GEN
AOC	airport operationg certificate	GEN	NOHOL	not holding	ATC
AOCC	Airline Operations Control Center	AIM	NOIFN	no information	GEN
AOCP	aircraft out of commission for parts	GEN	NOMAD	Naval Oceanographic Meteorological Automatic Device	GEN
AOE	airport of entry	GEN	NONEG	negative replies not required	GEN
AOPA	Aircraft Owners and Pilots Association	GEN	NONRVSM	non−RVSM capable flight	ICAO
AP	airport	ICAO	NOPAC	North Pacific	ATC
AP	anomalous propagation	ATC	NOPAR	do not pass to Air Defense radar	ATC
AP	Autopilot system	AIM	NOPT	no procedure turn required	GEN
APAP	approach path alignment panel	GEN	NORAC	no radio contact	ATC
APAPI	abbreviated precision approach path indicator	ICAO	NORAD	North American Aerospace Defense Command	GEN
APC	area postive control	ATC	NORDO	no radio	GEN
APCH	approach	ICAO	NOREC	no record	GEN
APDC	Aircraft Parking/docking chart (followed by name/title)	ICAO	NOREP	no report	GEN
APL	airport lights	GEN	NORIV	no arrival report	ATC
APLCN	Appalachian	NWS	NORPI	no pilot balloon observation will be filed next collection unless weather changes significantly	NWS
APN	Apron	ICAO	NORR	no reply received	GEN
APNT	appoint	GEN	NORST	no restrictions	GEN
APP	approach control or approach control office	ICAO	NONSTD	nonstandard	PHAK
APPA	advise present position and altitude	ATC	NOPT	no procedure turn required	PHAK
APPR	appear	GEN	NOS	National Ocean Service	GEN
APR	airports program report	GEN	NOSI	now simultaneous	GEN
APREQ	approval request	GEN	NOSIG	no significant change	ICAO
APRNT	apparent	GEN	NOSPL	no special observations taken (weather reports only)	NWS
APROP	appropriate	GEN	NOSUM	NOTAM Summary	GEN
APRX	approxomate	GEN	NOTAM	Notice to Airmen	ICAO
APS	airborne pulse search rader	GEN	NOZ	normal operating zone	GEN
APS	airport planning standard	PHAK	NOZ	Normal operating zone	ICAO
APSG	after passing	ICAO	NPA	Nonprecision Approach	AIM
APU	Auxillary Power Unit		NPDES	National pillutant discharge elimination system	PHAK
APV	approve	GEN	NPI	nonprecision instrument	GEN
APV	approach with vertical guidance	AIM	NPIAS	national plan of intergrated airport system	PHAK
APVL	approval	GEN	NPRL	no parallel traffic	ATC
AQAFO	Aeronautical Quality Assurance Field Office	PHAK	NPRM	Notice of Proposed Rulemaking	ATC
AR	Atlantic Route	ATC	NPRS	nonpersistent	NWS
AR	authorization required	AIM	NR	near	GEN
ARAC	area airport checked	ATC	NR	number	GEN
ARAC	Army rader approach control facility	GEN	NRAB	Naval Reserve Air Base	GEN
ARCTR	FAA Aeronautical Center or Academy	PHAK	NRC	non reccuring charge	PHAK
ARAD	altitude radial	ATC	NRCS	national radio comminications systems	PHAK
ARB	Air Reserve Base	GEN	NRD	no record of destination	GEN
ARC	area chart	ICAO	NRH	no reply heard	ICAO
ARENA	areas noted for attention	AIM	NRP	North American route program	ATC
ARCP	air refueling control point	ATC	NRS	Navigation Reference System	AIM
AREP	air refuling egress point	ATC	NRV	nonrevenue	GEN
AREX	air refueling exit	ATC	NRW	narrow	GEN
AREFF	aircraft rescue and fire fightng alarm	ATC	NS	nimbostratus	NWS
ARF	airport reservation function	PHAK	NS	Nova Scotia	NWS
ARFF	Aircraft Rescue & Fire Fighting	NOTAM	NSA	National Security Area
ARFF IC	aircraft rescue and fire fighting incident commander	AIM	NSAP	national service assurance plan	PHAK
ARFFOK	airport rescue and fire fighting alarm checked	ATC	NSC	no significant cloud	ICAO
ARFOR	area forecast	GEN	NSC	Nonstandard C/A Code	ATC
ARINC	Aeronautical Radio, Incorporated	GEN	NSCSWD	no small craft or storm warning are being displayed	NWS
ARIP	air refueling initial point	ATC	NSP	nonstandard holding pattern	GEN
ARL	Aerial	ATC	NSRCATN	natiional strategy assurance plan	PHAK
ARLNO	Airline Office	PHAK	NSSFC	National Severe Storm Forecast Center	GEN
ARLO	Army Liason Officer	GEN	NSSL	national severe storms labrotory, normal OK	PHAK
ARMET	forecast upper wind and temperature at specific points	GEN	NSTP	nonstop	GEN
ARML	Airmail	GEN	NSW	no significant weather	METAR
ARND	Around	GEN	NSWEH	NWS regional headquarters	PHAK
ARNG	Arrange	GEN	NTAP	National Track Analysis Program	ATC
ARNOT	area notice	GEN	NTAP	Notices To Airmen Publication	ATC
ARO	air traffic services reporting office	GEN	NTE	not to exceed	GEN
ARO	Airport Reservation office	GEN	NTFND	no trouble found	GEN
ARP	aerodrome reference point	ICAO	NTFY	notify	GEN
ARP	airport reference point	GEN	NTL	National	ICAO
ARP	airport reservation position	GEN	NTO	name to	GEN
ARP	air-report	GEN	NTP	National transportaion policy	PHAK
ARPT	Airport	GEN	NTRP	no traffic reported	ATC
ARQ	automatic error correction equipment	GEN	NTSB	National Transportation Safety Board	GEN
ARR	arrival or arrive	ICAO	NTZ	no transgression zone	ATC
ARRA	American Recovery and Reinvestment Act of 2009	PHAK	NTZ	No transgression zone	ICAO
ARS	Air Rescue Services (USAF)	GEN	NUDET	nuclear detonation	GEN
ARS	special air-report	GEN	NVA	negative vorticity advection	NWS
ARSA	airport radar service area	ATC	NW	north-west	ICAO
ARSR	air route survellience radar	GEN	NWB	north-westbound	ICAO
ARST	arresting	ICAO	NWLY	northwesterly (weather reports only)	NWS
ARTC	Air Route Traffic Control	GEN	NWRN	northwestern (weather reports only)	NWS
ARTCC	Air Route Traffic Control Center	GEN	NWS	National Weather Service	GEN
ARTS	Automated Radar Terminal System	GEN	NWSO	Naval Weather Service Office	GEN
ARU	Airborne Radar Unit	GEN	NWSR	NWS weather excluding NXRD	PHAK
ARU	Airspace Reservation Unit (Canadian)	GEN	NXT	next	GEN
ARUNK	arrival unknown	ATC	NXRD	advanced weather radar system	PHAK
AS	altostratus	NWS	O/F	on file	GEN
ASAS	aviation safety analysis system	PHAK	O/R	on request	GEN
AS/R	automatic send/receive	GEN	O/T	overtime	GEN
ASAP	as soon as possible	GEN	OA	overhead approach	ATC
ASC	asscent	GEN	OAC	oceanic area control	GEN
ASCU	automatic scanning control unit	GEN	OAG	Official Airline Guide	GEN
ASCP	Aviation System Capacity Plan	PHAK	OALT	opperational acceptable level of traffic	PHAK
ASD	airspace docket	GEN	OANDR	operation and regulation	GEN
ASD	aircraft situation display	PHAK	OAOI	on and off instruments	ATC
ASDA	accelerate-stop distance available	ICAO	OARTS	oceanic air route tracking system	GEN
ASDE	airport surface detection equiptment	GEN	OAS	obstacle assessment surface	ICAO
ADSE-X	Airport Surface detection equiptment-Model X	AIM	OAT	outside air temperature	GEN
ASE	altimetry system error	ICAO	OAW	off airway weather station	PHAK
ASGN	assign	GEN	OB	on board	GEN
ASHTAM	volcanic ash advisory	ICAO	OBL	obliterate	GEN
ASI	altimeter setting indicator	GEN	OBND	outbound	ATC
ASIP	airspace flight inspection pilot	GEN	OBS	observe, observed, or observation	ICAO
ASL	above sea level	GEN	OBSC	obscure, obscured, or obscuring	ICAO
ASLAR	aircraft surge launch and recovery	PHAK	OBST	obstacle	ICAO
ASM	available seat mile	PHAK	OBST	obstruct	GEN
ASMD	assumed	ATC	OBSTN	obstruction	GEN
ASND	ascend	GEN	OC	obstruction chart	GEN
ASO	Southern Region, FAA	GEN	OC	on course	ATC
ASOS	automated surface observing system	NWS	OCA	obstacle clearance altitude	ICAO
ASP	airport system plan	GEN	OCA	oceanic control area	ICAO
ASP	airspace	GEN	OCAC	oceanic ATC	GEN
ASPH	asphalt	ICAO	OCAS	out of controlled airspace	ATC
ASQP	airline service quality performance	PHAK	OCFNT	occluded front	NWS
ASR	airport surveillance radar	GEN	OCH	obstacle clearance height	ICAO
ASRS	Aviation Saftey Reporting Systems	AIM	OCL	obstacle clearance limit	ICAO
ASSC	airport surface surveillance capability	AIM	OCLD	occlude	NWS
ASSOC	associate	GEN	OCLN	occlusion	NWS
ASST	assistant	GEN	OCNL	occasional	GEN
ASTA	airport surface traffic automation	PHAK	OCR	occur	GEN
ASV	airline schedule vendor	PHAK	OCS	obstacle clearance surface	ICAO
ASW	Southwest Region, FAA	GEN	OCTLA	out of control area	ATC
AT	air traffic	PHAK	ODALS	omnidirectional approach lighting system	GEN
ATA	Actual time of arrival	ATC	ODP	Obstacle Departure Procedure	AIM
ATA	Air Transport Association of America	GEN	ODAPS	Oceanic Display and Planning System	ATC
ATAM	at and maintain	ATC	OEI	engine inoperative
ATAR	above transmitted as received	GEN	OEP	operational evolution plan/ partnership	PHAK
ATAS	airspace and traffic advisory service	PHAK	OFA	Object free area	PHAK
ATC	air traffic control	ICAO	OFAS	overseas flight assistance service	GEN
ATCA	Air Traffic Control Association	GEN	OFC	office	GEN
ACTA	ATC Advises	ATC	OFDPS	offshore flight data processing system	PHAK
ACTAA	ATC assigned airspace	ATC	OFFL	official	GEN
ATCBI	ATC beacon interrogator	GEN	OFM	out for maintenance	GEN
ATCC	ATC clears	ATC	OFP	occluded frontal passage	NWS
ATCCC	Air Traffic Control Command Center	PHAK	OFP	original flight plan	GEN
ATCF	ATC facility	GEN	OFSHR	offshore	NWS
ATCH	attach	GEN	OFT	outter fix time	PHAK
ATCO	Air Taxi Commercial Operator	PHAK	OFW	off watch	GEN
ATCOR	ATC operations representative	GEN	OFXT	outer fix time	ATC
ATCR	ATC requests	ATC	OFZ	Obstacle free zone	ICAO
ATCRB	air traffic control radar beacon	PHAK	OG	on ground	ATC
ATCRBS	Air traffic control radar beacon system	AIM	OGN	Originate	ICAO
ATCSCC	ATC system command center	GEN	OHD	overhead	ICAO
ATCT	Airport Traffic Control Tower	GEN	OI	on instruments	ATC
ATD	actual time of departure	ATC	OINT	omni intersection	GEN
ATFC	account traffic	GEN	OIS	operational information system	ATC
ATFM	air traffic flow managment	ICAO	OIS	Obstacle Identification Surface	AIM
ATIS	automatic terminal information service	ICAO	OJT	on-the-job training	GEN
ATISR	ATIS recorder	PHAK	OK	operating normally	GEN
ATLC	Atlantic	NWS	OK	We agree or it is correct	ICAO
ATM	air traffic managment	ICAO	OLDI	On line data interchange	ICAO
ATM	air traffic manager	ATC	OLS	optical landing system	ATC
ATM	authentification maneuver	ATC	OM	outer marker	ICAO
ATMS	advanced traffic management system	PHAK	OMB	office of managment and budget	PHAK
ATMT	attempt	GEN	OMSG	our message	GEN
ATMTC	attempt to contact	GEN	OMTNS	over mountains	NWS
ATN	Aeronautical Telecomminications Network	GEN	ONER	oceanic navigational error report	ATC
ATND	attend	GEN	ONSHR	on shore	NWS
ATO	aeronautical telecommunications operator	GEN	ONT	Ontario	NWS
ATO	Air Traffic Organization	GEN	ONW	on watch	GEN
ATODN	AUTODIN terminal (FUS)	PHAK	OOT	out of tolerance	GEN
ATOMS	air traffic operations managment system	PHAK	OPA	opaque, white type of ice formation	ICAO
ATOVN	auotvon (facility)	PHAK	OPC	operational control	ICAO
ATOG	allowable take-off gross weight	GEN	OPDT	opposite direction traffic	GEN
ATP	actual time of penetration	ATC	OPER	operate	GEN
ATP	air traffic procedures	GEN	OPLT	operational acceptale level of traffic	PHAK
ATPAC	Air Traffic Procedures Advisory Commitee	GEN	OPMET	operational meteorological (information)	ICAO
ATR	air transport rating	GEN	OPN	open	ICAO
ATREP	air traffic representative	GEN	OPN	operation	GEN
ATRLS	actual time of release	ATC	OPNML	operations normal	GEN
ATS	Air Traffic Service		OPR	operate, operator, operational	ICAO
ATSCCP	Air Traffiv Service Contingency	GEN	OPS	operations	ICAO
ATT	American Telephone and Telegraph Company	GEN	OPSNET	operations network	ATC
ATT	Attitude retention system	AIM	OPSPECS	Operation specifications
ATTM	at this time	GEN	OPSW	operational switch	PHAK
ATTN	attention	GEN	OPX	off premisis	PHAK
AT-VASIS	Abbreviated T visial approach slope indicator system	ICAO	ORD	order, indication of	ICAO
ATZ	aerodrome traffic zone	ICAO	ORD	Chicago O’Hare International Airport	AIM
AUGRA	authority granted	GEN	ORGPHC	orographic	NWS
AURBO	Auroroa Borealis	NWS	ORIG	original	GEN
AUREQ	authority is requested	GEN	ORL	overrun lights	GEN
AUTH	authority	GEN	ORS	over range station	ATC
AUTH	autorized or autorization	ICAO	OSV	ocean station vessel	NWS
AUTO	automatic	ICAO	OT	on time	ATC
AUTOB	automatic waether reporting system	GEN	OTAS	on top and smooth	NWS
AUW	all up in weight (gross weight)	GEN	OTFC	overflight traffic	GEN
AUX	auxilary	GEN	OTLK	outlook	NWS
AIZ	authorize	GEN	OTP	on top	ATC
AVN	Avation Standards National Field Office, Oklahoma City	PHAK	OTR	other	GEN
AVBL	Available	NOTAM	OTRW	otherwise	GEN
AVON	AUTOVON service	PHAK	OTS	organized track system	GEN
AWC	Aviation weather center	AIM	OTS	out of service	GEN
AWIS	airport weather information	PHAK	OUBD	outbound	ICAO
AWOS	automated weather observing system	NOTAM	OV	location (PIREP only)	ATC
AWSS	automated weather sensor system	NOTAM	OVC	overcast	NWS
AWP	Aviation Weather Processor	PHAK	OVD	overdue	GEN
AWPG	aviation weather products generator	PHAK	OVHD	overhead	GEN
AWS	air weather station	PHAK	OVLA	overlay	GEN
AWY	airway	PHAK	OVNGT	overnight	GEN
AWTT	aviation weather technology transfer	AIM	OVR	over	GEN
AWW	severe weather forcast alert	AIM	OVRN	overrun	GEN
AZM	azimuth	NOTAM	OVSEA	overseas	GEN
BAASS	Bigelow Aerospace Advanced Space Studies	AIM	OVTK	overtake	GEN
BA FAIR	braking action fair	PHAK	OW	one way	GEN
BA NIL	braking action nil	PHAK	OWF	optimum working frequency	GEN
BA POOR	braking action poor	PHAK	OXY	oxygen	GEN
BANS	BRITE alphanumeric system	PHAK	P	in RVR indicates visibility greater than highest reportable sensor value (e.g. P600FT)	METAR
BART	billing analysis reporting tool (GSA software tool)	PHAK	P	Pacific Standard Time (time group only)	NWS
BASIC	basic contract observing station	PHAK	P	polar (air mass)	NWS
BASOP	military base operations	PHAK	P	prohibited area	ICAO
BBS	bulletin board system	AIM	P/CG	pilot controller glossary	GEN
BC	back course		P6SM	visibility greater than 6 SM (TAF only)	METAR
BC	Patches	TAF/ METAR	PA	precision approach	GEN
BCA	benefit/cost analysis	PHAK	PA	pressure altitude	GEN
BCN	beacon	PHAK	PABX	Private automated branch exchange	PHAK
BCR	benefit/cost ratio	PHAK	PAC	Pacific	NWS
BDAT	digitized beacon data	PHAK	PACF	parent FSS assumes control of part-time FSS	GEN
BECMG	becoming group		PACOTS	pacific organized track system
BERM	snowbank(s) containing earth/gravel	PHAK	PAD	Packet assemler/ dissassembler	PHAK
BL	Blowing	TAF/ METAR	PADRA	pass to air defense radar	ATC
BLW	below	PHAK	PAEW	personnel and equipment working	GEN
BMP	best management practices	PHAK	PAJA	parachute jumping activities	GEN
BND	bound	PHAK	PALS	precision approach lighting system	ICAO
BOC	Bell Operating Company	PHAK	PALT	present altitude	ATC
bps	bits per second	PHAK	PAM	peripheral adapter module	PHAK
BR	Mist	TAF/ METAR	PANS	procedures for air navigation services	ICAO
BRI	basic rate interface	PHAK	PAPI	precision approach path indicator	ICAO
BRITE	bright radar indicator terminal equipment	PHAK	PAR	precision approach radar	ICAO
BRG	bearing	PHAK	PAR	Preferred Arrival Route	AIM
BRL	building restriction line	PHAK	PARA	paragraph	GEN
BTN	between	NOTAM	PAREN	parenthesis	GEN
BUEC	backup emergency communication	GEN	PARL	parallel	ICAO
BUIC	backup interceptor control	ATC	PARROT	Transponder	GEN
BUL	bulletin	GEN	PARROT	Position adjustable range reference orientation transponder	ATC
BUR	bureau	GEN	PAT	pattern	GEN
BUS	business	GEN	PATC	Precision approach terrain chart	ICAO
BY	blowing spray (weather reports only)	METAR	PATWAS	pilots automatic telephone weather answering service	GEN
BYD	beyond	GEN	PAU	present address unknown	GEN
BZR	buzzer (radar)	GEN	PAX	passenger	ICAO
C	celsius	GEN	PBCT	proposed boundary crossing time	GEN
C	Central Standard Time (time groups only)	NWS	PBRF	pilot briefing	PHAK
C	centre (runway ID)	ICAO	PBL	probable	NWS
C	circling (approach and landing charts)	ATC	PBS	public buildings service	GEN
C	continental (air mass)	NWS	PBX	private branch exchange	PHAK
C/A	Coarse/Acquisition	ATC	PC	Personal Computer	AIM
CA	clear above (PIREP only)	ATC	PCA	positive control area	GEN
C/S/S/N	capacity/safety/security/noise	PHAK	PCD	proceed	ICAO
CAA	civil aviation authority; Clean Air Act	PHAK	P/CG	Pilot/Controller Glossary	AIM
CAAS	Class A Airspace	ATC	PCK	pilot check	ATC
CAB	civil aeronautics board		PCL	pilot controlled lighting	GEN
CAC	change to approach control or changing to approach control	ATC	PCL	Pilot controlled lighting	ICAO
CAC	contact approach control	ATC	PCM	Pulse code modulation	PHAK
CACT	civil air carrier turbojet	GEN	PCN	pavement classification number	ICAO
CADO	Chief, Airport District Office	GEN	PCPN	precipitation	NWS
CAM	Canadian Armed Forces Transport Command	GEN	PCS	permanent change of station	GEN
CAMP	continuous airworthiness maintenance program.	AIM	PCT	percent	ICAO
CAN	Canada	NWS	PD	period	GEN
CANFORCE	Canadian Armed Force	GEN	PDAR	preferential arrival/departure route (Stage A)	GEN
CANO	catalogue number	GEN	PDC	Pre-departure clearance	ICAO
CANOT	Canadian NOTAM	GEN	PDDC	proceed directly on course	ATC
CANR	Canadian NORAD Region	GEN	PDN	public data Network	PHAK
CAO	change of appointing office	GEN	PDMT	predominant	NWS
CAP	Civil Air Patrol	GEN	PDMT	predominate	NWS
CAP/IS	combined approach control/ international station	GEN	PDOP	Position Dilution of Precision	ATC
CAPD	climb at pilot s discretion	ATC	PDR	preferential departure route (Stage A)	GEN
CARF	Central Altitude Reservation Facility	PHAK	PDW	priority delayed weather	NWS
CAPT	captain	GEN	PEN	peninsula	NWS
CARA	check area airports	GEN	PENT	penetrate or penetration	ATC
CARF	central altitude reservation function	GEN	PER	performance	ICAO
CARIB	Caribbean	NWS	PERCOM	peripheral communications	GEN
CARTS	Common automated radar terminal systems	AIM	PERF	perforator	GEN
CARU	Canadian Airspace Reservation Unit	GEN	PERM	permanent	ICAO
CAS	calibrated airspeed	ATC	PFD	Personal Flotation Device	AIM
CAS	collision avoidance system	GEN	PFD	primary flight display
CASCDS	cascades	NWS	PFC	passanger facility charges	PHAK
CASFO	Civil Aviation Security Office	PHAK	PFSV	pilot to forecaster service	GEN
CAT	category	ICAO	PGP	planning grant program	PHAK
CAT	clear air turbulence	GEN	PGTSND	Puget Sound	NWS
CAT II	Catagory II		PHYS	physical	GEN
CATX	climb and cross	ATC	PIB	Pre-flight information bulletin	ICAO
CAU	Crypto Ancillary Unit	PHAK	PIBAL	pilot balloon observation	NWS
CAUFN	caution advised until further notice	GEN	PIC	pilot in command	GEN
CAVOK	cloud and visibility OK	NWS	PinS	Point−in−Space	AIM
CAVU	clear or scattered clouds and visibility greater than ten miles	NWS	PIR	precision instrument runway	GEN
CAWS	common aviation weather subsystem	NWS	PIREP	pilot weather report	GEN
CB	cumulonimbus	NWS	PIRFC	pilot requests forecast	GEN
CBAS	Class B airspace	ATC	PISE	no pilot balloon observation due to unfavorable sea conditions	NWS
CBI	computer based instruction	PHAK	PISO	no pilot balloon observation due to snow	NWS
CBSA	cumulonimbus mamma	NWS	PIT	pilot instructor training	GEN
CBMAM	Class B surface area	ATC	PIWI	no pilot balloon observation due to high, or gusty, surface wind	NWS
CBSA	carbon copy	GEN	PJE	parachute jumping exercise	ICAO
CC	cirrocumulus	NWS	PK WND	peak wind (weather reports only)	NWS
CC	continental control area	GEN	PL	ice pellets	METAR
CCA	Class C airspace	ATC	PLA	practice low approach	ICAO
CCAS	Central Computer Complex	GEN	PLASI	pulsating visual approach slope indicators	ATC
CCC	Regional Communications Control Center	GEN	PLAT	present latitude	ATC
CCCC	staff communications	PHAK	PLF	private line telephone	GEN
CCCH	central computer complex host	PHAK	PLN	flight plan	ICAO
CCD	City (or County) Civil Defense Director at____	GEN	PLOB	place of birth	GEN
CCFP	collaborative convective forecast product	ATC	PLONG	present longitude	ATC
CCLDS	clear of clouds	ATC	PLS	please	GEN
CCLKOB	counterclockwise orbit	ATC	PLT	private line teletypewriter	GEN
CCLKWS	counterclockwise	NWS	PLVL	present level	ICAO
CCS7-NI	Communication Channel Signal-7-Network Interconnec	PHAK	PLW	plow (snow)	NWS
CC&O	customer cost and obligation	PHAK	PM	post meridiem	GEN
CCSD	Command Communications Service Designator	PHAK	PMA	Parts manafactuer approval
CCRU	complete crew	GEN	PMS	program managment system	PHAK
CCRZ	climb and cruise	ATC	PMSN	permission	GEN
CCSA	Class C surface area	ATC	PMT	permit	GEN
CCSL	standing lenticular cirrocumulus	NWS	PN	prior notice required	ICAO
CCTLR	chief controller	GEN	PNHDL	panhandle	NWS
CCU	Central Control Unit	PHAK	PNR	point of no return	ATC
CCUS	cleared Customs	GEN	PO	dust devils	METAR
CD	Controller display	AIM	PO	post office	GEN
CD	candela	ICAO	PO	purchase order	GEN
CD	civil defense	GEN	POA	privately owned aircraft	GEN
CD	clearance delivery	GEN	POB	persons on board	ICAO
CDAS	Class D airspace	ATC	POC	proceed or proceeding on course	ATC
CDC	computer display channel	GEN	POC	portable oxygen concentrator
CDFNT	cold front	NWS	POFZ	Precision Obstacle Free Zone	AIM
CDI	course deviation indicator	AIM	POH/AFM	Pilot’s Operating Handbook/Airplane Flight Manual
CDM	collaborative decision making	ATC	POI	Principal Operations Inspector	AIM
CDN	coordination	ICAO	POLIC	police station	PHAK
CDO	communications duty officer	GEN	POS	positive	GEN
CDSA	Class D surface area	ATC	POSS	possible	ICAO
CDR	Coded departure route	AIM	POP	Point of termination	PHAK
CD	clearance delivery; common digitizer	PHAK	POT	Point of termination	PHAK
CDAS	Class D Airspace	PHAK	POV	privately owned vehicle	GEN
CDSA	Class D surface area	PHAK	PP	pay period (number)	GEN
CDT	controlled departure time	PHAK	PPI	plan position indicator	ICAO
CDTI	cockpit display of traffic information	PHAK	PPIMS	personal property information managment system	PHAK
CE	communications equipment	GEN	PPINA	radar weather report not available (or omitted for a reason different than those otherwise stated)	NWS
CEAS	Class E airspace	ATC	PPINE	radar weather report no echoes observed	NWS
CELNAV	celestial navigation	GEN	PPINO	radar weather report equipment inoperative due to breakdown	NWS
CENGR	civil engineer	GEN	PPIOK	radar weather report equipment operation resumed	NWS
CENPAC	Central North Pacific	ATC	PPIOM	radar weather report equipment inoperative due to maintenance	NWS
CENTX	central telephone exchange	PHAK	PPR	prior permission required	ICAO
CER	climb en route	ATC	PPS	propose	GEN
CERAP	combined center/RAPCON	GEN	PPSN	present position	ATC
CERT	certificate	GEN	PR	partial	METAR
CERTIF	certification	GEN	PR	photo reconnaissance	GEN
CESA	Class E surface area	ATC	PRBL	probable	GEN
CEP	capacity enhancement program	PHAK	PRBLTY	probability	NWS
CEQ	council on environmental quality	PHAK	PRBO	position relief briefing observed	ATC
CERAP	center radar approach control; combined center radar approach control	PHAK	PRCF	parent FSS returns control of part-time FSS	GEN
CESA	Class E surface area	PHAK	PRCHT	parachute	GEN
CF	change frequency to	ICAO	PRCTN	precaution	GEN
CFA	controlled firing area	ATC	PRECD	precede	GEN
CFAD	composite flight data processing	GEN	PREF	preferred	ATC
CFADC	Canadian Forces Air Defense Command	GEN	PRES	pressure	GEN
CFAP	cleared for approach	ATC	PRESFR	pressure falling rapidly	NWS
CFC	central flow control	PHAK	PRESRR	pressure rising rapidly	NWS
CFCF	Central Flow Control Facility	PHAK	PREV	previous	GEN
CFCS	central flow control service	PHAK	PRFG	fog partial	METAR
CFR	Code of Federal Regulations	PHAK	PRI	primary	ICAO
CFIT	Controlled flight into terrain	AIM	PRIM	primary	GEN
CFM	confirm	GEN	PRIN	principal	GEN
CFM	Confirm or I confirm	ICAO	PRIND	present indications are	GEN
CFN	confine	GEN	PRIRA	primary radar	GEN
CFP	cold front passage	NWS	PRJMP	pressure jump (weather reports only)	NWS
CFPL	carryover from previous log	ATC	PRKG	parking	ICAO
CRF	Code of Federal Regulations	GEN	PRM	Precision Runway Monitor	AIM
CFWSU	central flow weather service unit	GEN	PRN	pseudo random noise	GEN
CFWP	central flow weather processor	PHAK	PROB	probability	ICAO
CFWU	Central flow weather unit	PHAK	PROB30	slight chance	METAR
CFY	clarify	GEN	PROB40	probability 40 percent	METAR
CG	Coast Guard	GEN	PROC	procedure	ICAO
CGAS	Class G airspace	ATC	PROCD	proceed	GEN
CGAS	Coast Guard Air Station	GEN	PROG	prognosis or prognostic	NWS
CGL	circling guidance light	ICAO	PROG	progress	GEN
CGLS	Coast Guard LORAN Station	GEN	PROP	propeller	GEN
CGSTN	congestion	GEN	PROPA	propagation	GEN
CH	channel	ICAO	PROSIG	procedure signal	GEN
CH	This is a channel-continuity-check of transmission to permit comparison of your record of channel- sequence numbers of messages received on the channel	ICAO	PROV	provisional	ICAO
CHAP	chapter	GEN	PRP	prepare	GEN
CHARC	characteristic	GEN	PRSNT	present	NWS
CHC	chance	NWS	PRST	persist	GEN
CHG	change	GEN	PRVD	provide	GEN
CHGO	changing over	ATC	PS	passenger service	GEN
CHM	chemicals	GEN	PS	plus	NWS
CHNL	channel	GEN	PSBL	possible	GEN
CHOK	check okay	GEN	PSBT	pilot self-briefing terminal	GEN
CHOV	changeover	ATC	PSDN	public switched data network	PHAK
CHRG	charge	GEN	PSG	passage	NWS
CHSPK	Chesapeake	NWS	PSG	passing	NWS
CHTR	charter	GEN	PSGR	passenger	GEN
CI	cirrus	NWS	PSN	position	ICAO
CIC	controller in charge	GEN	PSNAL	personal	GEN
CIDIN	common ICAO data interchange network	ICAO	PSNL	personnel	GEN
CIFP	cancel IFR flight plan	ATC	PSNRP	position report	ATC
CIFR	cancel IFR clearance previously given	ATC	PSP	pierced steel planking	ICAO
CIFRR	Common IFR Room	GEN	PSR	packed snow on runway	NWS
CIG	ceiling	NWS	PSR	Primary surveillance radar	ICAO
CINCNORAD	Commander in Chief, North American Aerospace Defense Command	GEN	PSRI	position subject to return of incumbent	GEN
CIRNAV	circumnavigate	ATC	PSRS	position subject to rotating shifts	GEN
CIRNOT	circuit notice	GEN	PST	Pacific Standard Time	GEN
CIRVIS	communications instructions for reporting vital intelligence sightings	ATC	PT	procedure turn	GEN
CIT	near or over large towns	ICAO	PTC	plan to clear	ATC
CIV	civil	ICAO	PTC	positive target control	ATC
CK	check	ICAO	PTCHY	patchy	NWS
CKT	circuit	GEN	PTCP	participate	GEN
CL	centre line	ICAO	PTLY	partly	NWS
CL	closing station	GEN	PTN	portion	GEN
CL	course line	ATC	PTN	procedure turn	ICAO
CLA	clear type of ice formation	ICAO	PTP	point-to-point	ATC
CLB	climb	ATC	PTR	printer	GEN
CLBI	climb immediately	ATC	PTRS	Performance Tracking and Reporting System.
CLBN	crash locator beacon	GEN	PTS	polar track structure	ICAO
CLBR	calibration	ICAO	PUB	public	GEN
CLC	course line computer	PHAK	PUBL	publish	GEN
CLD	cloud	NWS	PUP	pickup	GEN
CLG	calling	ICAO	PVA	positive vorticity advection	NWS
CLKOB	clockwise orbit	ATC	PVASI	pulsating/steady visual approach slope indicator	GEN
CLKWS	clockwise	GEN	PVC	permanent virtual circuit	PHAK
CLIN	contract line item	PHAK	PVD	plan view display	PHAK
CLN	colon	GEN	PVL	prevail	GEN
CLNC	clearance	GEN	PVLT	prevalent	GEN
CLODA	closing date	GEN	PVT	private	GEN
CLOTO	close this office	GEN	PWB	pilot weather briefing	GEN
CLR	clears, or cleared to, or clearance	ICAO	PWI	proximity warning indicator	ATC
CLRAP	cleared as planned	ATC	PWINO	precipitation identifier information not available (weather reports only)	NWS
CLRS	clear and smooth	NWS	PWR	power	GEN
CLSD	closed	ICAO	PWRNO	power failure	GEN
CLST	celestial	ATC	PWROK	power restored	GEN
CLT	calculated landing time	PHAK	PY	spray	METAR
CLU	circuit line up	GEN	QDL	Do you intend to ask me for a series of bearings? Or I intend to ask you for a series of bearings	ICAO
CM	centimeter	ICAO	QDM	magnetic heading	ICAO
CMA	comma	GEN	QDR	magnetic bearing	ICAO
CMB	climb to or climbing to	ICAO	QFE	atmospheric pressure at airport elevation	ICAO
CMNC	commence	GEN	QFLOW	quota flow control procedures	GEN
CMP	Configuration, mantience and procedures		QFU	magnetic orientation of runway	ICAO
CMPCT	compact	GEN	QGE	What is my distance to your station or Tour distance to my station is	ICAO
CMPL	complete or completed or completion	ICAO	QICP	Qualified Internet Communications Provider
CMPLT	complete	GEN	QJH	Shall I run my test tape/a test sentence	ICAO
CMPLX	complex	GEN	QLFY	qualify	GEN
CMPSN	compsition	GEN	QLTY	quality	GEN
CMPT	component	GEN	QN	question	GEN
CMS	contruction maintenance supervisor	GEN	QNH	altimeter sub-scale setting to obtain elevation when on the ground	ICAO
CMSN	commission	GEN	QNTY	quantity	GEN
CMSND	commissioned	PHAK	QSP	Will you relay to free of charge or I will relay to free of charge	ICAO
CNL	cancel	PHAK	QSTNRY	quasistationary	NWS
CNCL	cancel	NWS	QTA	Shall I cancel telegram number ? Or cancel telegram number	ICAO
CNCNT	concurrently	GEN	QTE	true bearing	ICAO
CNCT	connect	GEN	QTF	Will you give me the position of my station according to the bearings taken by the D/F station which you control or the position of your station according to the bearings taken by the D/F stations that I control was latiude longitude (or other indication of position), class ….at….hours	ICAO
CNDN	Canadian	NWS	QTR	quarter	GEN
CNMPS	Canadian Minimum Navigation Performance Specification Airspace	PHAK	QUAD	quadrant	GEN
CNL	cancel	GEN	QUE	Quebec	NWS
CNLFP	cancel flight plan	ATC	QUJ	Will you indicate the TRUE track to reach you or the TRUE track to reach me is degrees at hours	ICAO
CNS	comminications, navigation and surveillance	ICAO	R	Acknowledgement of receipt (message handling)	GEN
CNS	Consolidated NOTAM System	ATC	R	Received (acknowledgement of receipt)	ICAO
CNSTNT	consistent	GEN	R	restricted area (followed by identification)	ICAO
CNSP	consolidated NOTAM system processor	PHAK	R	right (runway identification)	ICAO
CNTR	center	GEN	R	runway (used in RVR measurement)	METAR
CNTRL	centeral	GEN	R/O	receive only	GEN
CNTRLN	centerline	GEN	R/OC	receive, only centers	GEN
CNVG	converge	GEN	RA	rain	METAR
CNVRT	convert	GEN	RA	Resolution Advisory
CNVSN	conversion	GEN	RAA	Remote Airport Advisory	ATC
CNVTV	convective	NWS	RAAF	Royal Australian Air Force	GEN
CO	company	GEN	RABA	no RAWIN obs., no balloons available	NWS
CO	county	GEN	RABAL	radiosonde balloon wind data	NWS
COA	Certificate of waiver or authorization		RABAR	radiosonde balloon release	NWS
COB	close of business	GEN	RAC	request altitude change	ATC
COC	climb on course	ATC	RAC	rules of the air and air traffic services	ICAO
COE	U.S. Army Corps of Engineers	PHAK	RACE	request altitude changes en route	ATC
COLL	collect	GEN	RACFI	radio and communication facilities inoperative	GEN
COM	communication	ICAO	RACO	no RAWIN obs., communications out	NWS
COMB	combine	GEN	RACON	radar responder beacon	GEN
COMCO	Command communications outlet	PHAK	RADAT	radiosonde observation data	NWS
COML	commercial	GEN	RADEP	radar departure	ATC
COMLO	compass locator	GEN	RADNO	report missing account radio failure	NWS
COMPR	compare	GEN	RADON	radar beacon	GEN
COMPRT	compartment	GEN	RADU	weather radar analysis and development unit	GEN
CONC	concrete	ICAO	RAF	Royal Air Force	GEN
CONCA	continue calling until	ATC	RAFC	regional area forecast center	ICAO
CONUS	Continental United States	PHAK	RAFI	radiosonde observation not filed	NWS
COND	comdition	ICAO	RAFRZ	radiosonde observation freezing levels	NWS
CONF	confidential	GEN	RAG	ragged	ICAO
CONFDC	confidence	NWS	RAG	runway arresting gear	ICAO
CONFIG	configuration	ATC	RAGF	remote air-ground facility	GEN
CONFIGN	configuration	GEN	RAHE	no RAWIN obs., no gas available	NWS
CONR	Continental NORAD Region	GEN	RAI	runway alignment indicator	ICAO
CONS	continuous	ICAO	RAIS	Remote Airport Information Service	AIM
CONSO	CONSOLAN Facility	GEN	RAICG	radiosonde observation icing at	NWS
CONSOL	consol beacon	GEN	RAIL	runway alignment indicator lights	GEN
CONSOLAN	low or medium frequency long range navigational aid	GEN	RAIM	Receiver Autonomous Integrity Monitoring	ATC
CONST	construction	ICAO	RAIM	Receiver autonomous integrity monitoring	ICAO
CONT	continue(s) or continued	ICAO	RAJAM	radar jamming	ATC
CONTDVD	Continental Divide	NWS	RALT	regardless of altitude	ATC
CONTH	continue to hold	ATC	RAM	returned account mechanical	GEN
CONTR	contract	GEN	RAMOS	remote automatic meterological observing system	PHAK
CONTRAILS	condensation trails	NWS	RAOB	radiosonde observation	NWS
COORD	coordinate	GEN	RAPCO	radar appraoch control USAF	PHAK
COORD	Coordinates	ICAO	RAPCON	radar approach control	GEN
COP	changeover point	GEN	RAPI	radiosonde report already sent in PIBAL collection	GEN
COPCOM	Controllers Operations and Procedures Committee	GEN	RARAD	radar advisory	GEN
COPT	completed procedure turn	ATC	RAREP	radar weather report	NWS
COR	correct or corrected or correction	GEN	RASC	Regional AIS system centre	ICAO
CORAS	corridor assignment	ATC	RASH	rain showers	ICAO
COREQ	confirming requisition follows	GEN	RASN	rain and snow or showers of rain and snow	METAR
CORP	private corporation other than ARINC or MITRE	PHAK	RATCC	radar air traffic control center	PHAK
COT	at the coast	ICAO	RATCF	radar ATC facility (USN)	GEN
COV	cover	ICAO	RAVU	radiosonde analysis and verification unit	NWS
CP	circular polarization	GEN	RAWE	no RAWIN obs., unfavorable weather	NWS
CPA	crash phone activated	GEN	RAWI	no RAWIN obs., high and gusty winds	NWS
CPBL	capable	GEN	RAWIN	upper winds obs. (by radio methods)	NWS
CPD	coupled	GEN	RAWX	returned account weather	GEN
CPDLC	Controller-pilot data link communications	ICAO	RB	rescue boat	ICAO
CPF	complete power failure	GEN	RB	right base	ATC
CPL	current flight plan	ICAO	RB	relative bearing
CPME	Calibration performance monitoring equipment	GEN	RBC	rotating beam ceilometer	PHAK
CPN	air transport pulse radar navigation aid	GEN	RBDE	radar bright display equipment	GEN
CPS	air transport pulse radar search	GEN	RBI	relative bearing indicator
CPTY	capacity	GEN	RBDT	Ribbon Display Terminals	AIM
CRA	conflict resolution advisory	PHAK	RPDPE	Rader bomb scoring squadron	PHAK
CRAD	composite radar data processing	GEN	RBN	radio beacon	GEN
CRAF	civil reserve air fleet	GEN	RBOC	report back on course	ATC
CRC	circle	GEN	RBOF	report back on frequency	ATC
CRC	Cyclic redundancy check	ICAO	RBS	radar bomb scoring	GEN
CRCHF	crew chief	GEN	RBS PP(RBS+++)	ration by schedule plus compression	ATC
CRDA	converging runway display aid	PHAK	RBSS	Rader bomb scoring squadron	PHAK
CRLC	circulate	GEN	RC	reverse course	ATC
CRS	course	GEN	RC	road reconnaissance	GEN
CRT	cathode ray tube	GEN	RCA	reach cruising altitude	ICAO
CRTFY	certify	GEN	RCADV	reverse course and advise	ATC
CRYPTO	cryptographic	GEN	RCAG	remote communications air/ground facility	GEN
CRZ	cruise	ICAO	RCALT	reach cruising altitude	ATC
CRZAM	cruise and maintain	ATC	RCC	Rescue Coordination Center	GEN
CRZWTR	cruise well to right	ATC	RCCC	regional communications ait/ground facility	PHAK
CS	Call sign	ICAO	RCD	radar cloud detection report	NWS
CS	cirrostratus	NWS	RCDNA	radar cloud detection report not available	NWS
CS/C	combined station/center	GEN	RCDNE	radar cloud detection report no echoes observed	NWS
CS/T	combined station/tower	GEN	RCDNO	radar cloud detector inoperative due to breakdown until	NWS
CSA	communications service autorization	PHAK	RCDOM	radar cloud detector inoperative due to maintenance until	NWS
CSATR	climb so as to reach	ATC	RCF	radio communication failure	ICAO
CSATX	climb so as to cross	ATC	RCF	radiocommunication failure	ICAO
CSDR	consider	GEN	RCF	remain on company frequency	ATC
CSDRBL	considerable	GEN	RCH	reach	GEN
CSIS	centralized storm information	PHAK	RCH	reach – call sign for U.S. AirForce, Air Mobility Command (USAFAMC)	MIL
CSLDT	consolidate	GEN	RCIU	remote control interface unit	PHAK
CSO	customer service offive	PHAK	RCK	radio check	ATC
CST	coast	NWS	RCKY	Rockies (mountains)	NWS
CSR	communications service request	PHAK	RCL	runway center line	ICAO
CSS	central site system	PHAK	RCLL	runway center line lights	ICAO
CTA	control area	ICAO	RCLM	runway centerline marking	GEN
CTA/FIR	control area/flight information region	PHAK	RCLR	radio communications link repeater	GEN
CTAF	common traffic advisory frequency	ATC	RCLS	runway centerline light system	GEN
CTAM	climb to and maintain	ATC	RCLT	radio communications link terminal	GEN
CTAS	controlled airspace	ATC	RCMD	recommend	GEN
CTAX	climb to and cross	ICAO	RCN	Royal Canadian Navy	GEN
CTC	contact	ATC	RCO	remote communication outlet	GEN
CTCC	change to center control or changing to center control	ATC	RCOM	en route communications	GEN
CTCC	contact center control	ATC	RCON	reconfiguration	ATC
CTCEN	contact center	NWS	RCPT	receipt	GEN
CTGY	category	ICAO	RCR	runway condition reading	GEN
CTL	control	GEN	RCRD	record	GEN
CTLA	control area	GEN	RCS	Rehost Computer System	ATC
CTLB	control boundary	GEN	RCU	remote control unit	PHAK
CTLR	controller	GEN	RCV	receive	GEN
CTLZ	control zone	GEN	RCVNO	receiving capability out	GEN
CTMA	Center Traffic Management Advisor	PHAK	RD	Rotor Diameter	AIM
CTN	caution	GEN	RDARA	regional and domestic air route area	GEN
CTR	control zone	ICAO	RDAT	radar data (digitized)	GEN
CTRAC	common terminal radar approach control	GEN	RDC	reduce	GEN
CTSKLS	Catskills	NWS	RDG	ridge	NWS
CU	cumulus	NWS	RDH	reference datum height (ILS)	ICAO
CUF	cumuliform	ICAO	RDL	radial	ICAO
CUFRA	cumulus fractus	NWS	RDO	radio	ICAO
CUSNO	customs has been notified	GEN	RDP	radar data processing	PHAK
CUST	customs	ICAO	RDS	radius	GEN
CUPS	consolidated uniform payroll system	PHAK	RDSIM	runway delay simulation model	PHAK
CVFP	cancel VFR flight plan	ATC	RDSP	redispatch	GEN
CVFR	controlled visual flight rules	PHAK	RDSPA	redispatch accepted	GEN
CVTS	compressed video transmission service	PHAK	RDWND	radar dome wind	NWS
CVINO	clearance void if not off	ATC	RE	regard	GEN
CVN	convene	GEN	REBAT	reference BATCS report	GEN
CVR	Cockpit voice recorder	ICAO	REC	receive or receiver	ICAO
CVR	cover	GEN	RECLR	recleared	ICAO
CVRS	computerized voice reservation system	ATC	RECON	reconnaissance	GEN
CWA	center weather advisory		RECON	reference conversation	GEN
CW	continuous wave	ICAO	REDL	runway edge light	ICAO
CWM	change weight manifest	GEN	REF	reference	ICAO
CWRC	climb well to right of course	ATC	REFONE	reference our telephone conversation	GEN
CWSU	center weather service unit	GEN	REFORM	reference form	GEN
CWTR	climb well to right	ATC	REG	registration	ICAO
CWY	clearway	ICAO	REG	regulation	GEN
CXA	cancel approved arrival	ATC	REGAL	range and elevation guidance for approach and landing	ATC
CXD	cancel approved departure	ATC	REIB	report established in block	ATC
CYC	cyclonic	NWS	REIL	runway end identifier lights	GEN
CYCLGN	cyclogenesis	NWS	REINV	reference invoice	GEN
CYL	cylinder	GEN	REL	Runway Entrance Lights	AIM
CZM	coastal zone management	GEN	RELBL	reliable	GEN
D	danger area	ICAO	RELCT	relocate	GEN
DA	decision altitude	ICAO	RELCTD	relocated	PHAK
DA	departure approved	ATC	RELET	reference letter	GEN
DAAR	deviation approved as requested	ATC	REMES	reference message	GEN
DABBS	DITCO automated bulletin board system	PHAK	REMT	relief electronic maintenance technician	GEN
DABRK	daybreak	NWS	RENL	runway end light	ICAO
DAE	district airport engineer	GEN	RENOT	regional office notice	GEN
DAIRE	direct altitude and identification readout equipment	GEN	REOC	report when established on course	ATC
DALGT	daylight	GEN	REP	report or reporting point	ICAO
DAP	do all possible	GEN	REP	represent or representative	GEN
DAPD	descend at pilot s discretion	ATC	REP	research project	GEN
DAR	Designated Agency Representative	PHAK	REPAML	reply by airmail	GEN
DARC	direct access radar channel	PHAK	REPBS	reference PBS message	GEN
DASI	digital altimeter setting indicator	GEN	REPERF	reperforator	GEN
D-ATIS	Data link Automatic Terminal Information Service	ICAO	REPMES	reply by message	GEN
D-ATIS	Digital−Automatic Terminal Information Service	ATC	REPML	reply by mail	GEN
DB	decibel	GEN	REPTWX	reply by TWX	GEN
DB	describe	GEN	REQ	request	GEN
DBA	doing business as	GEN	REQID	request if desired	GEN
dBA	decibels A-weighted	PHAK	REQON	request consideration	GEN
DBASI	digital barometer altimeter setting indicator	GEN	REQRCM	request your recommendation	GEN
DBCRC	Defense Base Closure and Realignment Commission	PHAK	REQSTD	requested	GEN
DBE	disadvantaged business enterprise	PHAK	RERTE	reroute	ICAO
DBL	double	GEN	RES	reserve	GEN
DBMS	database mangment systems	PHAK	RES	resident	GEN
DBTF	doubtful	GEN	RESA	Runway end safety area	ICAO
DBRITE	digital bright radar indicator tower equipment	PHAK	RESP	response	GEN
DC	direct current	GEN	RESTR	restrict	NWS
DCA	Defense Communications Agency	GEN	REWRC	report when established well to right of course	ATC
DCA	Ronald Reagan Washington National Airport		RF	radio frequency	GEN
DCAA	dual call, automatic answer device	PHAK	RF	reception fair (radio logs only)	ATC
DCAVU	clear or scattered clouds and visibility greater than ten, remainder of report missing (weather reports only)	NWS	RFA	request further airways	ATC
DCCU	data communications control unit	PHAK	RFI	radio frequency interference	GEN
DCD	double channel duplex	ICAO	RFI	ready for issue	GEN
DCE	data communications equiptment	PHAK	RFL	refuel	GEN
DCF	deputy chief	GEN	RFM	Rotorcraft Flight Manual	AIM
DCKG	docking	ICAO	RFS	refuse	GEN
DCLRT	decelerate	ATC	RFTO	ready for take-off	ATC
DCM	defense combat maneuvers	ATC	RFFS	rescue and firefighting services.
DCMSN	decommission	GEN	RG	range (lights)	ICAO
DCMSND	decommissioned	PHAK	RG	reception good (radio logs only)	ATC
DCMT	document	GEN	RGD	ragged	NWS
DCP	Data Collection Package		RGLR	regular	GEN
DCPC	Direct controller-pilot communications	ICAO	RGN	region	GEN
DCR	decrease	GEN	RH	relative humidity	NWS
DCRZ	descend to and cruise	ATC	RHC	Right-hand circuit	ICAO
DCS	defense communications system	GEN	RHI	range height indicator	GEN
DCS	double channel simplex	GEN	RHINO	radar echo height information not available	NWS
DCT	direct	ICAO	RHINO	radar range height indicator not operating on scan	NWS
DDA	dedicated digital access	PHAK	RIF	reclearance in flight	ICAO
DDD	direct distance dialing	PHAK	RIF	reduction in force	GEN
DDM	difference in depth of modulation	GEN	RIL	Runway Intersection Lights	AIM
DE	From (used to precede the call sign of the calling station)	ICAO	RIMAT	must ride company material	GEN
DEA	Drug Enforcement Agency	PHAK	RIOGD	Rio Grande	NWS
DEDS	data entry and display system	PHAK	RIS	reports identification symbol	GEN
DECCO	Defense Commercial Communications Office	GEN	RITC	Request in Trail Climb	ATC
DEF	defense	GEN	RITD	Request in Trail Descent	ATC
DEFCON	Defense Readiness Conditions	GEN	RITE	right (direction of turn)	ICAO
DEG	degree	ICAO	RL	report immediately upon leaving	ATC
DEGS	degrees	PHAK	RL	report leaving	ICAO
DEIS	Draft Environmental Impact Statement	PHAK	RL	general aviation releiver airport	PHAK
DELPHO	deliver by telephone	GEN	RLA	relay to	ICAO
DEMOL	demolition	GEN	RLANO	relay equipment out of operation	GEN
DENEB	fog dispersal operations	ICAO	RLAOK	relay equipment resumed operation	GEN
DEP	depart	ATC	RLBG	relative bearing	GEN
DEP	departure	ICAO	RLC	report landing completed	ATC
DEPT	department	GEN	RLCE	request level change en route	ICAO
DEPPROC	departure procedures	PHAK	RLETFL	report leaving each thousand foot level	ATC
DER	departure end of runway	ICAO	RLIM	Runway Light Intensity Monitor	AIM
DES	descend to or descending to	ICAO	RLLS	runway lead-in lighting system	ICAO
DESTN	destination	GEN	RLNA	request level not available	ICAO
DETRESFA	Distress Phase Code (Alerting Service)	ATC	RLS	release	GEN
DEV	deviation	ATC	RLSTN	relay station	GEN
DEW	distant early warning	GEN	RLTK	rhumbline track	ATC
DEWIZ	distant early warning identification zone	GEN	RLTV	relative	GEN
DF	direction finder	PHAK	RLV	relieve	GEN
DFAX	digital facsimile	PHAK	RLVL	report level	GEN
DFCLT	difficult	GEN	RM	remarks (PIREP only)	ATC
DFDR	Digital flight data recorder	ICAO	RMCC	remote monitor control center	PHAK
DFI	direction finding indicator	PHAK	RMCF	remote monitor control facility	PHAK
DFL	daily flight log	GEN	RMI	Radio Magnetic Indicator	AIM
DFNT	definite	GEN	RMK	remark	ICAO
DFRS	differs	GEN	RML	radio magnetic indicator
DFTI	distance from touchdown indicator	GEN	RMLR	radar microwave link repeater	GEN
DFUS	diffuse	GEN	RMLT	radar microwave link terminal	GEN
DGCGO	dangerous cargo	GEN	RMM	remote maintience monitoring	PHAK
DGNL	diagonal	GEN	RMMS	remote maintience monitoring system	PHAK
DGPS	differential global positioning satellite(system)	PHAK	RMN	remain	GEN
DGR	danger	GEN	RMNDR	remainder	PHAK
DH	decision height	ICAO	RMPCK	ramp check	ATC
DI	delay indefinite	ATC	RMRK	remark	GEN
DI	departure approval request for IFR flight	ATC	RMS	remote monitoring subsystem	PHAK
DIAM	diameter	GEN	RMSC	remote monitoring subsystem concentrator	PHAK
DID	direct inward dial	PHAK	RN	reception nil (radio logs only)	ATC
DIF	diffuse	ICAO	RNAV	area navigation	ICAO
DIP	direct inward dial	PHAK	RNFL	rainfall	NWS
DIR	director	GEN	RNG	Army National Guard	GEN
DIRF	direction finding	PHAK	RNG	radio range	ICAO
DISABLD	disabled	GEN	RNLS	resume normal speed	ATC
DISC	discontinue	GEN	RNP	required navigation performance	ICAO
DISEM	disseminate	GEN	RO	regional office	GEN
DIST	distance	ICAO	RO	regulated output	GEN
DIST	district	GEN	ROBEPS	radar operating below prescribed standard	NWS
DISTR	distribute	GEN	ROBEX	regional OPMET bulletin exchange	ICAO
DITCO	Defense Information Technology Contracting Office Agency	PHAK	ROC	rate of climb	ICAO
DIV	divert	ICAO	ROCC	NORAD Region Operations Control Center	GEN
DIV	division	GEN	ROD	rate of descent	ICAO
DKTS	Dakotas	NWS	RODA	regardless of destination airport	ATC
DLA	delay or delayed	ICAO	ROFOR	route forecast	ICAO
DLAD	delay or delayed	NOTAM	ROLET	reference letter from our office	GEN
DLAC	delay account of	ATC	ROMEMO	reference our memorandum	GEN
DLAT	delay time	ATC	ROMES	reference message from our office	GEN
DLC	delay clearance or delayed clearance	ATC	RON	remaining overnight	GEN
DLIC	Data link initiation capability	ICAO	ROPBS	reference PBS message from our office	GEN
DLT	delete	GEN	RORQN	reference requisition from our office	GEN
DLVR	deliver	GEN	RORU	rest of route unchanged	ATC
DLVY	delivery	GEN	ROSA	report of service activity	PHAK
DLY	daily	GEN	ROT	rotate	GEN
DLY	Daily	ICAO	ROTEL	reference telegram from our office	GEN
DMAAC	Defense Mapping Agency Aerospace Center	GEN	ROTG	rotating	GEN
DMAHC	Defense Mapping Agency Hydrographic Center	GEN	ROTWX	reference our TWX	GEN
DME	distance measuring equipment	ICAO	ROV	report over	ATC
DME/N	standard DME	AIM	RP	reception poor (radio logs only)	ATC
DME/P	Precision DME	AIM	RP	right traffic pattern	ATC
DMEG	DME-collocated with glide slope	GEN	RP	restoration priority	PHAK
DMEL	DME-collocated with localizer	GEN	RPA	request present altitude	ATC
DMER	DME-tactical air navigation with DME only commissioned	GEN	RPAT	RNP Parallel Approach Runway Transitions
DMEV	DME-collocated with VOR	GEN	RPC	restoration priority code	PHAK
DMG	damage	GEN	RPD	rapid	NWS
DMN	Data Multiplexing Network	PHAK	RPFOD	reported for duty	GEN
DMNT	dominant	GEN	RPG	radar processing group	PHAK
DMO	Directives Management Officer, FAA	GEN	RPI	Radar position indicator	ICAO
DMSH	diminish	NWS	RPL	repetitive flight plan	ICAO
DMSTN	demonstration	GEN	RPLC	replace	GEN
DNA	Defense Nuclear Agency	GEN	RPM	rotation per minute	GEN
DNG	danger	ICAO	RPOC	report proceeding on course	ATC
DNL	day-night equivalent sound level (also called Ldn)	PHAK	RPR	repair	GEN
DNS	dense	NWS	RPRT	report	GEN
DNSLP	downslope	NWS	RPS	radar position symbol	ICAO
DNSTRM	downstream	NWS	RPSG	report passing	ATC
DNWND	downwind	ATC	RPT	repeat	GEN
DO	Deputy Commander for Operations	GEN	RPT	Repeat or I repeat	ICAO
DO	ditto	GEN	RPZ	runway protection zone	PHAK
DOB	date of birth	GEN	RQ	Indication of a request	ICAO
DOC	Department of Commerce	GEN	RQ	request	GEN
DOD	Department of Defense	GEN	RQCL	request clearance	ATC
DOD	direct outward dial	PHAK	RQDCZ	request clearance to depart VFR and leave control zone at	ATC
DOE	Department of Energy	GEN	RQECZ	request clearance to enter control zone VFR at	ATC
DOI	Department of Interior	PHAK	RQMNTS	requirements	ICAO
DOLLY	data link	GEN	RQN	requisition	GEN
DOM	domestic	ICAO	RQOF	request on file	ATC
DOS	Department of State		RQP	request flight plan	ICAO
DOT	Department of Transportation	GEN	RQP	request permission	GEN
DOT-1	Transport One-Secretary of Transportation	ATC	RQPP	request present position	ATC
DOT-2	Transport Two-Deputy Secretary of Transportation	ATC	RQR	require	GEN
DP	deep	NWS	RQRD	required	PHAK
DP	dew point temperature	ICAO	RQRP	request reply	GEN
DP	Instument Departure Procedure	AIM	RQS	request supplementary flight plan	ICAO
DPCR	departure procedure	ATC	RQTAO	request time and altitude over	ATC
DPNG	deepening	NWS	RR	low or medium frequency radio range stations	GEN
DPT	depth	ICAO	RR	radar range station	GEN
DPU	data processing unit	AIM	RR	report immediately upon reaching	ATC
DPTH	depth	NWS	RR	report reaching	ICAO
DR	dead reckoning	ATC	RRBN	round robin	ATC
DR	direct route	GEN	RRCVR	remote receiver	GEN
DR	low drifting	METAR	RRH	remote reading hygrothermometer	PHAK
DR	drifting	TAF/METAR	RRHS	remote reading hydrometer	PHAK
DRCT	direct	GEN	RRL	runway remaining lights	GEN
DRCTN	direction	GEN	RRP	runway reference point	GEN
DRDU	low drifting dust	METAR	RRPD	runway reference point downwind	GEN
DRFT	drift	NWS	RRPU	runway reference point upwind	GEN
DRG	during	ICAO	RRS	remainder of same route	ATC
DRIR	direct readout infrared	GEN	RRTE	reroute	ATC
DRMS	Distance Root Mean Square	ATC	RRWDS	remote radar weather display	PHAK
DRR	Deployment Readiness Review	ATC	RRWSS	RWDS sensor site	PHAK
DRSA	low drifting sand	METAR	RS	receiver station	GEN
DRSN	low drifting snow	METAR	RS	record special observation (weather reports only)	NWS
DRT	Diversion Recovery Tool	AIM	RS	right side	ATC
DRVSM	Domestic reduced vertical seperation minimun	AIM	RSA	runway saftey area	PHAK
DUATS	direct user access terminal system	AIM	RSAT	runway saftey action team	PHAK
DVA	diverse vector area	AIM	RSC	rescue sub-center	ICAO
DVFR	defense visual flight rules	AIM	RSCD	runway surface condition	ICAO
DVRSN	diversion	AIM	RSCU	rescue	GEN
DRZL	drizzle	NWS	RSG	rising	NWS
DS	domestic services (island operations)	GEN	RSN	reason	GEN
DS	dust storm	METAR	RSOPN	resumed operation	GEN
DSATR	descend so as to reach	ATC	RSP	responder beacon	ICAO
DSATX	descend so as to cross	ATC	RSR	en route surveillance radar	ICAO
DSB	double sideband	ICAO	RSS	remote speaking system	PHAK
DSCNT	descent	ATC	RSTR	restrict	GEN
DSCS	digital satellite compression service	PHAK	RSU	runway supervisory unit	GEN
DSGND	designated	GEN	RSVN	reservation	GEN
DSIPT	dissipate	NWS	RT	right turn after take-off	ATC
DSN	Defense Switching Network	GEN	RT	round trip	GEN
DSND	descend	ATC	RT & BLT	radar tracking and beacon tracking level	PHAK
DSNDI	descend immediately	ATC	RTAD	remote tower alphanumerics display	PHAK
DSNT	distant	GEN	RTB	return to base	ATC
DSPL	display	GEN	RTCA	radio technical commission for aeronatics	PHAK
DSPLC	displace	GEN	RTD	delayed	ICAO
DSPLCD	displaced	PHAK	RTE	route	GEN
DSPN	disposition	GEN	RTF	radiotelephone	GEN
DSPRL	dispersal	GEN	RTG	radiotelegraph	GEN
DSR	desire	GEN	RTHL	runway threshold light	ICAO
DSRGD	disregard	GEN	RTMTR	remote transmitter	GEN
DST	distort	GEN	RTN	return	ICAO
DSTC	distance	GEN	RTND	retained	GEN
DSTND	destined	ATC	RTNE	routine	GEN
DSUA	dynamic special use airspace	PHAK	RTO	report time over	ATC
DTAM	descend to and maintain	ATC	RTP	regional transportaion plan	PHAK
DTAX	descend to and cross	ATC	RTR	remote transmitter/receiver	ATC
DTE	data terminal equipment	GEN	RTR	returning to ramp	ATC
DTF	data transmission feature	GEN	RTRD	retard	GEN
DTG	date time group	GEN	RTRN	return	GEN
DTHR	Displaced runway threshold	ICAO	RTS	return to service	ICAO
DTL	detail	GEN	RTT	radioteletypewriter	GEN
DTLN	international dateline	NWS	RTX	report time crossing	ATC
DTR	data transmission request	GEN	RTZL	runway touchdown zone light	ICAO
DTRM	determine	GEN	RUF	rough	NWS
DTRT	deteriorate	NWS	RUFORM	reference your form	GEN
DTS	Diplomatic Telecommunications Service	GEN	RULET	reference letter from your office	GEN
DTW	dual tandem wheels	ICAO	RUMEMO	reference your memorandum	GEN
DU	widespread dust	METAR	RUMES	reference message from your office	GEN
DUAT	direct user access terminal	PHAK	RURQN	reference requisition from your office	GEN
DUATS	direct user access terminal system	GEN	RUT	standard regional route transmitting frequencies	ICAO
DUC	dense upper cloud	ICAO	RUTEL	reference telegram from your office	GEN
DUPE	duplicate	GEN	RUTWX	reference your TWX	GEN
DUPE	This is a duplicate message (to be used in AFS as a procedure signal)	ICAO	RV	radar vector	ATC
DUR	duration	ICAO	RV	rescue vessel	ICAO
DURC	during climb	ATC	RVO	runway visibility by observer	GEN
DURD	during descent	ATC	RVR	runway visual range	ICAO
DURG	during	GEN	RVRA	RVR ten minute average	GEN
DURN	duration	GEN	RVRANO	RVR ten minute average not available	GEN
DV	distinguished visitors	GEN	RVRENO	RVR ten minute extremes not available	GEN
DVFR	defense VFR	GEN	RVRM	RVR midpoint	GEN
DVLP	develop	GEN	RVRMNO	RVR midpoint not available	GEN
D-VOLMET	Data link VOLMET	ICAO	RVRNO	RVR not available	GEN
DVOR	doppler VHF omni-directional radio range	ICAO	RVRR	RVR rollout	GEN
DVRG	diverge	GEN	RVRRNO	RVR rollout not available	GEN
DVRSN	diversion	GEN	RVRT	RVR touchdown	GEN
DVV	downward vertical velocity	NWS	RVRTNO	RVR touchdown not available	GEN
DW	dual wheels	ICAO	RVS	revise	GEN
DWG	drawing	GEN	RVSM	Reduced Vertical Separation Minimum	ICAO
DWNDFTS	downdrafts	NWS	RVV	runway visibility value	GEN
DWPNT	dew point	NWS	RVVNO	RVV not available	GEN
DWRC	descend well to right of course	ATC	RW	runway	PHAK
DWTR	descend well to right	ATC	RWDS	same as RRWDS	PHAK
DX	duplex	GEN	RWRC	remain well to right of course	ATC
DYSIM	dynamic simulator	PHAK	RWSL	Runway Status Light	AIM
DZ	drizzle	ICAO	RWP	real time weather processor	PHAK
E	east or eastern longitude	ICAO	RWY	runway	ICAO
E	Eastern Standard Time (time groups only)	NWS	RY	runway	GEN
E	ending of precipitation (time in minutes) (weather reports only)	NWS	S	South or southern latitude	ICAO
E	engine-generator	GEN	S/S	sector suite	PHAK
EA	enviromental assesment	PHAK	S/A	semi-annual	GEN
E/G	equatorial (air mass)	GEN	S/RC	send/receive center	GEN
E/R	exchange and repair	ATC	SA	duststorm, sandstorm, rising dust or sand	METAR
EACLN	expect approach clearance	ATC	SA	record observation (weather reports only)	NWS
EACNL	expect approach clearance not later than	ATC	SA	sand, sandstorm, or dusting	ICAO
EADIZ	entering air defense identification zone	GEN	SA	surveillance approach	GEN
EARTS	en route automated radar tracking system	ATC	SAA	special activity airspace	NOTAM
EAS	equivalent airspeed	ATC	SABH	simultaneous automatic broadcast homer	GEN
EAT	expected approach time	ICAO	SAC	stragegic air command	PHAK
EB	eastbound	GEN	SADT	same direction traffic	GEN
EBND	eastbound	ATC	SAFI	semi-automatic flight inspection	GEN
ECA	enter control area	ATC	SAFI	semi-automatic flight inspection aircraft	GEN
ECAS	enter controlled airspace	ATC	SAFO	Safety Alerts For Operators	AIM
ECD	except change departure to read	GEN	SALS	short approach lighting system	GEN
ECM	electronic counter measures	ATC	SALS	simple approach lighting system	ICAO
ECMSN	electronic counter measure mission	GEN	SALSF	short approach lighting system with sequenced flashing lights	GEN
ECOM	en route communications	ATC	SAM	System Area Monitor	AIM
ECR	except change route to read	GEN	SAN	sanitary	ICAO
ECSP	electronic specialist	GEN	SAO	surface aviation observation	NWS
ECVFP	expanded charted visual flight procedures	PHAK	SAP	as soon as possible	ICAO
EDA	early departure authorized	ATC	SAPD	speed at pilots discretion	GEN
EDC	expect departure clearance at	ATC	SAR	search and rescue	ICAO
EDCT	estimated departure clearance (time)	ATC	SARPS	standards and recommended practices	ICAO
EDR	expect departure release at	ATC	SAS	Stability Augmentation System	AIM
EEE	Error (to be used in AFS as a procedure signal)	ICAO	SASK	Saskatchewan	NWS
EEM	electronic equipment modification	GEN	SAT	Saturday	ICAO
EENGR	electrical engineer	GEN	SATCOM	satellite communication	ICAO
EEP	end exercise point	GEN	SATFY	satisfy or satisfactory	GEN
EET	estimated elapsed time	ICAO	SATR	so as to reach	ATC
EFA	entire field available	GEN	SATR	special air traffic rules	GEN
EFAS	En Route Flight Advisory Service	AIM	SAVASI	simplified abbreviated visual approach slope indicator	GEN
EFC	expect further clearance at	ATC	SAWRS	supplementary aviation weather reporting station	GEN
EFCT	effect	GEN	SAYTA	say time able	ATC
EFF	effective	GEN	SB	southbound	ICAO
EFIS	electronic flight information systems	PHAK	SBAS	satellite−based augmentation system	ICAO
EFR	expect further routing	ATC	SBFC	standby for further clearance	ATC
EFTO	encrypt for transmission only	GEN	SPGB	state block grant program	PHAK
EFV	Enhanced Flight Visibility	AIM	SBND	southbound	ATC
EFVS	extended operations		SBSD	subside	NWS
EFVS	Enhanced Flight Vision System	AIM	SC	stratocumulus	NWS
EG	emergency gear	GEN	SCC	System Command Center	PHAK
EGECON	electronic geographic coordinator navigation system	GEN	SCAN	self-correcting automatic navigation	GEN
EHA	expect higher altitude	ATC	SCANO	automatic scanning unit out of service	GEN
EHF	extremely high frequency (30000 to 300000 MHz)	ICAO	SCAOK	automatic scanning unit returned to service	GEN
EIAF	expanded inward access features	PHAK	SCAT	security control of air traffic	GEN
EIS	environmental impact statement	PHAK	SCAT−1 DGPS	Special Category I Differential GPS	AIM
EIT	electronic installation technician	GEN	SCATANA	automatic scanning unit out of service	GEN
ELAT	estimated latitude	GEN	SCC	System Command Center	GEN
ELBA	emergency location beacon – aircraft	ICAO	SCLN	semicolon	GEN
ELEC	electric	GEN	SCND	second (in line)	GEN
ELECN	electrician	GEN	SCS	single channel simplex	GEN
ELEV	elevate or elevation	ICAO	SCSL	standing lenticular stratocumulus	NWS
ELIP	elliptical	GEN	SCT	scattered	NWS
ELMT	electronic mechanic technician	GEN	SCTR	sector	GEN
ELNGT	elongate	NWS	SCTY	security	GEN
ELONG	estimated longitude	GEN	SCVTS	switched compressed video telecommunications service	PHAK
ELR	extra long range	ICAO	SDB	scheduled data base	GEN
ELSW	elsewhere	GEN	SDBY	standby	GEN
ELT	emergency locator transmitter	GEN	SDF	simplified directional facility	GEN
ELWRT	electrowriter	PHAK	SDIS	Switched digital integrated service	PHAK
EM	emission	ICAO	SDP	service delivery point	PHAK
EMAS	Engineered Materials Arresting System	AIM	SD ROB	radar weather report	PHAK
EMBD	embedded (in cloud layer)	ICAO	SDS	switched data system	PHAK
EMBDD	embedded	NWS	SE	south-east	ICAO
EMDO	Engineering and Manufacturing District Office	GEN	SE	system engineer	GEN
EMERG	emergency	ICAO	SEADRM	seadrome	GEN
EMI	electronic maintenance inspector	GEN	SEB	south-eastbound	ICAO
EMPS	en route maintenance processor system	PHAK	SEC	second (time)	GEN
EMS	environmental management system	PHAK	SECMR	sector manager	GEN
E-MSAW	en route automated minimum safe altitude	PHAK	SECRA	secondary radar	GEN
EMSU	environment meteorological support unit	NWS	SECT	sector	ICAO
EMT	electronic maintenance technician	GEN	SEL	space environment laboratory	GEN
ENAV	en route navigational aids	PHAK	SELF	simplified short approach lighting system with sequenced flashing lights	PHAK
ENCTR	encounter	GEN	SELCAL	selective calling	ATC
END	stop-end (related to RVR)	ICAO	SELS	severe local storms	NWS
ENDCE	endurance	GEN	SELY	southeasterly (weather reports only)	NWS
ENDG	ending	GEN	SENS	sensitivity	GEN
ENE	east-north east	ICAO	SEPN	separation	GEN
ENERN	east-northeastern (weather reports only)	NWS	SEQ	sequence	GEN
ENEWD	east-northeastward (weather reports only)	NWS	SER	service	ICAO
ENG	engine	ICAO	SERN	southeastern (weather reports only)	NWS
ENGR	engineer	GEN	SES	supervisory electronics specialist	GEN
ENHNCD	enhanced	GEN	SESC	space environment service center	GEN
ENHNCMNT	enhancement	GEN	SET	stack entry time	ATC
ENR	en-route	ICAO	SEV	severe	ICAO
ENRC	En-route chart (followed by name/ title)	ICAO	SF	standard form	GEN
ENRT	en route	GEN	SFA	single frequency approach	GEN
ENTR	entire	GEN	SFAR-38	special federal aviation regulation 38	PHAK
EOBT	estimated off-block time	ICAO	SFC	surface	ICAO
EOD	entered on duty	GEN	SFERICS	atmospherics	NWS
EOF	expected operations forecast	NWS	SFL	sequence flashing lights	GEN
EP	en route penetration	ATC	SFO	sector field office	GEN
EPA	Environmental Protection Agency	PHAK	SFO	simulated flame out	ATC
EPE	Estimate of Position Error	AIM	SFR	Special Flight Rules	AIM
EPI	expanded position indicator	ATC	SFPP	stored flight plan program	ATC
EPS	Engineered Performance Standards	PHAK	SFRA	special flight rules area	GEN
EPSS	enhanced packet switced service	PHAK	SFU	sector field unit	GEN
EQCRT	equipment certified	GEN	SG	snow grains (weather reports only)	METAR
EQPT	equipment	ICAO	SGD	signed	GEN
EQUIP	equipment	GEN	SGD	solar-geophysical data	NWS
Equi-Time Point	a point on the route of flight where the flight time, considering wind, to each of two selected airports is equal		SGFNT	significant	GEN
ER	here	ICAO	SGL	signal	GEN
ERAD	en route radar (broadband)	GEN	SH	showers	METAR
ERMG	en route metering	ATC	SHF	super high frequency	GEN
ERSP	en route spacing program	ATC	SHFT	shift (weather reports only)	NWS
ERY	early	GEN	SHGR	hail showers	METAR
ESCAT	emergency security control of air traffic	GEN	SHGS	hail showers (small)	METAR
ESE	east-south east	ICAO	SHLW	shallow	NWS
ESEC	en route secondary radar beacon (broadband)	GEN	SHORN	short range navigation system	GEN
ESERN	east-southeastern (weather reports only)	NWS	SHP	standard holding procedure	GEN
ESEWD	east-southeastward (weather reports only)	NWS	SHPL	ice pellet showers	METAR
ESF	extended superframe format	PHAK	SHPO	state historic preservation officer	PHAK
ESNTL	essential	GEN	SHRA	rain showers	METAR
ESP	en route sequencing program	ATC	SHRT	short	GEN
EST	estimate or estimation	ICAO	SHRTLY	shortly	NWS
ESTAB	establish	GEN	SHRTWV	shortwave	GEN
ESV	expanded service volume	GEN	SHSN	snow showers	METAR
ESYS	en route equiptment systems	PHAK	SHTDN	shutdown	GEN
ET	electronic technician	GEN	SHUD	should	ATC
ETA	estimated time of arrival	GEN	SHWR	shower	NWS
ETARS	en route tracking automatic radar service	ATC	SI	straight-in approach	GEN
ETC	et cetera	GEN	SIA	standard instrument approach	GEN
ETD	estimated time of departure	GEN	SIAP	standard instrument approach procedure	GEN
ETE	estimated time en route	GEN	SID	standard instrument departure	ICAO
ETFL	each thousand foot level	ATC	SIC	service initionation charge	PHAK
ETG	enhanced target generator	PHAK	SIERNEV	Sierra Nevada	NWS
ETI	estimated information	ATC	SIF	selective identification feature	ICAO
ETIM	elapsed time	ATC	SIG	signature	GEN
ETMS	enhanced traffic managment system	PHAK	SIGMET	significant meteorological information	GEN
ETN	electronic telecomunications network	PHAK	SIGWX	significant weather	ICAO
ETO	estimated time over significant point	ICAO	SIM	simulated approach	ATC
ETOPS	extended operations		SIMMOND	airport and airspace simulation model	PHAK
ETOV	estimated time over	ATC	SIMUL	simultaneous/ly	ICAO
ETP	estimated time of penetration	ATC	SIP	state implementaion plan	PHAK
ETR	eastern test range	ATC	SIR	snow and ice on runway	NWS
EU	electronic unit	GEN	SIWL	single isolated wheel load	ICAO
EUO	emergency use only	GEN	SJP	standard jet penetration	GEN
EV	every	ICAO	SK	sky condition (PIREP only)	ATC
EVAC	evacuation	GEN	SKC	sky clear	METAR
EVAL	evaluate or evaluation	GEN	SKED	schedule	ICAO
EVAS	enhanced vortex advisory system	PHAK	SL	sea level	GEN
EVCS	emergency voice communications system	PHAK	SL	sick leave	GEN
EVE	evening	GEN	SLCT	select	GEN
EVS	electronic voice switching system	GEN	SLD	solid	NWS
EVT	expect vector to	ATC	SLGT	slight	GEN
EWINS	Enhanced Weather Information System	AIM	SLMM	simultaneous compass locator at middle marker	GEN
EWIS	as defined by § 25.1701 of this chapter , means electrical wiring interconnection system.		SLO	slow	GEN
EWR	Newark International Airpor	AIM	SLOM	simultaneous compass locator at outer marker	GEN
EXAM	examination	GEN	SLP	sea level pressure	METAR
EXC	except	ICAO	SLP	slope	GEN
EXCH	exchange	GEN	SLP	speed limiting point	ICAO
EXCLD	exclude	GEN	SLR	slush on runway	NWS
EXCLV	exclusive	GEN	SLRAP	standard low frequency range approach	GEN
EXCP	except	GEN	SLS	side lobe suppression	GEN
EXCT	execute	GEN	SLT	sleet	NWS
EXDLVY	expedite delivery	GEN	SLW	slow	ICAO
EXEC	executive	GEN	SM	statute mile	GEN
EXEC-1	President on board civil aircraft	GEN	SMC	squawk mode code	GEN
EXEC-1F	President s family is aboard aircraft	GEN	SMC	surface movement control	ICAO
EXEC-2	Vice President is aboard civil aircraft	GEN	SMGC	surface movement guidance and control	PHAK
EXEC-2F	Vice President s family is aboard aircraft	GEN	SMGCS	surface movement guidance and control system	GEN
EXER	exercise	ICAO	SML	small	GEN
EXP	expect	ICAO	SMPS	sector maintience processor subsystem	PHAK
EXPC	expect	GEN	SMR	statute mile radius	GEN
EXPED	expedite	GEN	SMR	surface movement radar	ICAO
EXPHO	expedite delivery by telephone	GEN	SMRY	summary	GEN
EXPS	express	GEN	SMS	synchronous meteorological satellite	GEN
EXQF	expanded quota flow	ATC	SMS	systems maintenance sector	GEN
EXREP	expedite mail reply	GEN	SMT	submit	GEN
EXSEC	extra section	GEN	SMTH	smooth	NWS
EXSHI	expedite shipment	GEN	SMTM	sometime	GEN
EXTD	extend	GEN	SMWHT	somewhat	GEN
EXTN	extension	GEN	SN	snow	ICAO
EXTRAP	extrapolate	NWS	SN	strategic navigation	GEN
EXTRM	extreme	NWS	SN	systems navigation	GEN
EXTSV	extensive	GEN	SNBNK	snowbank	NWS
F	Cleared to fix	ATC	SND	sand or sanded or sanding	GEN
F	fahrenheit	GEN	SNFLK	snowflake	NWS
F	flight inspection	GEN	SNGL	single	GEN
F&E	facility and equiptment	PHAK	SNOINCR	snow depth increase in past hour	NWS
FA	area forecast	NWS	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	ICAO
FA	fuel advisory	ATC	SNR	single to noise ratio also S/N	PHAK
FA	final approach	ATC	SNSH	snow showers	ICAO
FA CENTER	Aviation Area Forecast Center	GEN	SNW	snow	NWS
FAA	Federal Aviation Administration	GEN	SNWFL	snowfall	NWS
FAA	for an approach to	ATC	SOAP	spectrometric oil analysis program	ATC
FAA-1	SafeAir One-Federal Aviation Administration Administrator	ATC	SOAR	system of airports reporting	PHAK
FAA-2	SafeAir Two-Federal Aviation Administration Deputy Administrator	ATC	SOB	souls on board	ATC
FAAP	federal aid to airports program	GEN	SOC	service oversight center	PHAK
FAAR	FAA requirements	GEN	SOCC	NORAD Sector Operations Control Center	GEN
FAAAC	FAA aeronautical center	PHAK	SOMSG	see our message	GEN
FAACIS	FAA communications information system	PHAK	SOIA	Simultaneous Offset Instrument Approaches	AIM
FAATC	FAA technical center	PHAK	SOIR	simultanious operations on intersecting runways	PHAK
FAATSAT	FAA telecommunications satellite	PHAK	SOIWR	silmultanious operations on intersectiong wet runways	PHAK
FAC	facilities	ICAO	SOP	standard operating procedure	GEN
FAC	facility	GEN	SORAP	standard omni range approach	GEN
FACF	facility chief	GEN	SP	standard holding pattern	GEN
FACSFAC	Fleet Area Controlled and Surveillance Facility	ATC	SP	station pressure	NWS
FAD	fuel advisory departure	GEN	SPAN	stored program for alpha numerics	GEN
FAF	final approach fix	ICAO	SPB	seaplane base	GEN
FAFAB	FSS assumes flight-plan area and Service B	GEN	SPC	Storm Prediction Center	AIM
FAH	fahrenheit	NWS	SPCLY	especially	GEN
FAL	facilitation of international air transport	ICAO	SPD	speed	GEN
FAM	familiar or familiarization	GEN	SPEC	specification	GEN
FAMAE	following amendment authorized effective	GEN	SPECI	aviation selected special weather report	METAR
FAN	MKR fan marker	PHAK	SPKL	sprinkle	NWS
FAP	final approach point	ICAO	SPL	special	GEN
FAST	Final approach spacing tool	PHAK	SPL	supplementary flight plan	ICAO
FAR	Federal Aviation Regulations	GEN	SPLNS	south plains	NWS
FAROS	Final Approach Runway Occupancy Signal	AIM	SPO	strategic plan of operation	ATC
FATFL	FSS assumes control of tower frequencies and lights	GEN	SPOT	spot wind	ICAO
FAWP	final appraoch waypoint	AIM	SPS	Standard Positioning Service	AIM
FAX	facsimile	GEN	SPRD	spread	NWS
FB	Fly-By	AIM	SPRL	spiral	GEN
FBO	fixed-base operator	METAR	SPS	Standard Positioning Service	ATC
FBS	fall back switch	PHAK	SPT	strategic planning team	ATC
FC	funnel cloud	ATC	SQ	squall	METAR
plus FC	Tornado or waterspout	TAF/ METAR	SQDN	squadron	GEN
FCA	frequency change approved	GEN	SQK	squawk	ATC
FCC	Federal Communications Commission	GEN	SQLN	squall line	NWS
FCFSS	FAA Contract Flight Service Station	GEN	SR	standard range approach	GEN
FCO	facility coordination officer	ATC	SR	sunrise	ICAO
FCOM	FSS radio voice communications	PHAK	SRA	surveillance radar approach	ICAO
FCLT	freeze calculated landing time	PHAK	SRAP	sensor receiver and processot	PHAK
FCRP	field condition report	GEN	SRCH	search	GEN
FCPU	facility central processing unit	PHAK	SRE	surveillance radar element of precision approach radar system	ICAO
FCST	forecast	ATC	SRG	short range	ICAO
FCTA	flow control time of arrival	GEN	SRM	single-pilot resource management.
FCWOS	FAA Contract Weather Observing Station	GEN	SRND	surround	GEN
FD	Flight Director System	AIM	SRPN	special requisition priority number	GEN
FDAT	flight data	GEN	SRR	search and rescue region	ICAO
FDC	Flight Data Center	GEN	SRY	secondary	ICAO
FDDL	frequency division data link	GEN	SS	sandstorm	METAR
FDE	Fault Detection and Exclusion	AIM	SS	sunset	ICAO
FDEP	flight data entry and printout	ATC	SSALF	simplified short approach lighting system with sequenced flashers	GEN
FDI	Fault Detection and Isolation	ATC	SSALR	simplified short approach lighting system with runway alignment indicator lights	GEN
FDIO	flight data input/output	ATC	SSALS	simplified short approach lighting system	GEN
FDIOC	flight data input/output center	PHAK	SSALSR	simplified short approach light system with runway alignment indicator lights.
FDIOR	flight data input/output repeater	ATC	SSB	single sideband	ICAO
FDP	Flight data processing	PHAK	SSE	south-south east	ICAO
FDPS	Flight data processing system	ICAO	SSERN	south-southeastern (weather reports only)	NWS
FE	flight engineer	GEN	SSEWD	south-southeastward (weather reports only)	NWS
FED	federal	PHAK	SSNO	request no SIDs or STARs	ATC
FEIS	final environmental impact statement	PHAK	SSR	secondary surveillance radar	ICAO
FENKN	fuel supply unknown	ATC	SST	supersonic transport	ICAO
FENTL	fuel supply until	ATC	SSV	standard service volume.
FEP	front end processor	PHAK	SSW	south-south west	ICAO
FEW	1 or 2 octas (eighths) cloud coverage	METAR	SSWRN	south-southwestern (weather reports only)	NWS
FEXHA	fuel supply exhausted	ATC	SSWWD	south-southwestward (weather reports only)	NWS
FFAC	from facility	PHAK	ST	saint	GEN
FFC	for further clearance	ATC	ST	stratus	NWS
FFC	familiarization flight	GEN	STA	straight in approach	ICAO
FFS	full flight simulator		STADMR	station administrator	GEN
FFMN	fixed federal monitoring network	GEN	STAGN	stagnation	NWS
FG	fog	METAR	STALO	stabilized local oscillator	GEN
FGSB	FSS guarding Service B	GEN	STAR	standard instrument arrival	ICAO
FI/P	flight information (permanent)	GEN	STAR	standard instrument arrival	GEN
FI/T	flight information (temporary)	GEN	STARS	Standard Terminal Automation Replacement System
FIBI	filed but impracticable to transmit	NWS	STATE	military, customs, or police services	ICAO
FIC	Flight Information Center	GEN	STBL	stable	GEN
FICON	field condition	GEN	STBY	standby	ICAO
FIDO	Flight Inspection District Office	GEN	STCLB	start climb	ATC
FIFO	Flight Inspection Field Office	GEN	STD	standard	ICAO
FIFO-H	Flight Inspection Field Office – High Altitude	GEN	STDST	start descent	ATC
FIFP	filed IFR flight plan	ATC	STDY	steady	GEN
FIG	figure	GEN	STF	stratiform	ICAO
FIG	flight inspection group	GEN	STFRA	stratus fractus	NWS
FIL	filament	GEN	STFRM	stratiform	NWS
FILG	filling	NWS	STG	strong	NWS
FILS	florescan instrument landing system	GEN	STLT	satellite	GEN
FINO	weather report will not be filed for transmission	NWS	STM	storm	NWS
FIPS	federal information publication standard	PHAK	STMGR	station manager	GEN
FIR	Flight Information Region	GEN	STMP	special traffic management program	ATC
FIRAV	first available	GEN	STMUX	statistical data multiplexor	PHAK
FIRB	Flight Information Region Boundary	GEN	STN	station	GEN
FIRE	fire station	PHAK	STNR	stationary	ICAO
FIRG	firing	GEN	STNRY	stationary	NWS
FIRMR	federal information resourse managment	PHAK	STOL	short take-off and landing	GEN
FIRIV	arrival report will be filed with	ATC	STR	subject terminal control release	ATC
FIS	flight information service	GEN	STRO	stereo routes	GEN
FISA	automated flight information service	ICAO	STS	status	ICAO
FISDL	Flight Information Services Data Link	AIM	STWL	stopway light	ICAO
FL	flash advisory	NWS	STWY	stopway	GEN
FL	flight level	GEN	SUA	special use airspace	GEN
FLCTN	fluctuation	GEN	SUB	substitute	GEN
FLD	field	ICAO	SUBFIX	subject to correction	GEN
FLDST	flood stage	NWS	SUBJ	subject to	ICAO
FLG	falling	NWS	SUF	sufficient	GEN
FLG	flashing	ICAO	SUG	suggest	GEN
FLIDAP	flight data position	GEN	SUN	Sunday	ICAO
FLIP	flight information publication	GEN	SUP	supply	GEN
FLOWISM	traffic flow planning simulation		SUPCHG	supercharge	GEN
FLORL	fluorescent runway lighting (floodlight system)	GEN	SUPPL	supplement	GEN
FLR	flares	ICAO	SUPPS	regional supplementary procedures	ICAO
FLRY	flurry	NWS	SUPR	superior	GEN
FLT	flight	ICAO	SUPSD	supersede	GEN
FLTCK	flight check	ICAO	SUPT	superintendent	GEN
FLTO	flight orders	GEN	SUPVR	supervisor	GEN
FLTWO	flight watch outlet	GEN	SURPIC	surface picture	ATC
FLUC	fluctuating	ICAO	SUSP	suspend	GEN
FLW	follow	GEN	SVC	service	GEN
FLWIS	flood warning issued	NWS	SVCA	service a	PHAK
FM	fan marker	GEN	SVCA	service b	PHAK
FM	from	ICAO	SVCBL	serviceable	ICAO
FMA	final monitor aid	PHAK	SVCC	service c	PHAK
FMAP	fan marker approach	ATC	SVCO	service o	PHAK
FMF	facility master file	PHAK	SVFR	special VFR	GEN
FMH	fan marker located with radio beacon	GEN	SVFB	interphone service F (b)	PHAK
FMO	frequency management officer	GEN	SVFC	Interphone service F (c)	PHAK
FMIS	fts2000 managment information systems	PHAK	SVFD	interphone service F (D)	PHAK
FMS	Flight management system	ICAO	SVFO	interphone service F (A)	PHAK
FMT	format	GEN	SVFR	special visial flight rules	PHAK
FMU	flow management unit	ICAO	SVG	serving	GEN
FNA	final approach	ICAO	SVN	space vehicle number	GEN
FNCTN	function	GEN	SVR	severe	GEN
FNMS	FTS2000 network managment system	PHAK	SVRL	several	GEN
FNT	Front	NWS	SW	south-west	ICAO
FNTGNS	frontogenesis	NWS	SWAP	severe weather avoidance plan	GEN
FNTLYS	frontolysis	NWS	SWB	scheduled weather broadcast	GEN
FO	Fly-Over		SWB	south-westbound	ICAO
FOB	fuel on board	GEN	SWEPT	swept or broom/ broomed	PHAK
FOD	foreign object debris	GEN	SWLG	swelling	NWS
FOIA	freedom of information act	PHAK	SWLY	southwesterly (weather reports only)	NWS
FONE	telephone	GEN	SWRN	southwestern (weather reports only)	NWS
FORNN	forenoon	NWS	SWSL	supplemental weather service location	ATC
FONSI	finding of no significant impact	PHAK	SWY	stopway	ICAO
FP	flight plan	GEN	SX	stability index	NWS
FPA	flight plan area	ATC	SXN	section	NWS
FPA	Flight path angle		SYD	release subject your discretion	GEN
FPB	flight progress board	ATC	SYNOP	synoptic	NWS
FPDI	flight path deviation indicator	GEN	SYNS	synopsis	NWS
FPL	filed flight plan	ICAO	SYS	see your service	GEN
FPL	full performance level	ATC	SYS	system	GEN
FPM	feet per minute	GEN	T	Temperature	ICAO
FPN	fixed pulse radar navigation aid	GEN	T	trace (weather reports only)	NWS
FPNO	flight plan not received	GEN	T	training	GEN
FPP	from present position	ATC	T	tropical (air mass)	NWS
FPR	flight plan route	GEN	T	true (bearing)	GEN
FPRC	for possible reclearance	ATC	T1MUX	T1 multiplexer	PHAK
FPWA	further particulars when available	ATC	T/R	transportation request	GEN
FPV	Flight Path Vector	AIM	TA	temperature (PIREP only)	ATC
FPNM	Feet Per Nautical Mile	AIM	TA	total aboard	GEN
FQT	frequent	GEN	TA	transition altitude	ICAO
FR	fuel remaining	GEN	TA	traffic advisory
FRC	full route clearance	GEN	TAA	terminal arrival area.
FRD	fix-radial-distance	ATC	TAAS	terminal advance automation system	PHAK
FREQ	frequency	ICAO	TAC	terminal area chart	GEN
FRFAB	FSS returns flight-plan area and Service B	GEN	TACAN	tactical air navigational aid	ICAO
FRI	Friday	ICAO	TACLO	tactical air command liaison officer	GEN
FRH	fly runway heading	ATC	TACR	tactical air navigation	GEN
FRM	form	GEN	TAD	ATC tower, approach and departure control facility	ATC
FRMG	forming	NWS	TAF	aerodrome forecast	ICAO
FRMN	formation	GEN	TAF	terminal forecast	METAR
FRNG	firing	ICAO	TAIL	tail wind	ICAO
FROPA	frontal passage	NWS	TAND	tandum	GEN
FROSFC	frontal surface	NWS	TANDA	time and attendance report	GEN
FRQ	frequent	ICAO	TAO	TACAN only	ATC
FRSB	FSS returns Service B	GEN	TAO	time and altitude over	ATC
FRST	frost	NWS	TAPER	temporary appointment pending establishment of a register	GEN
FRTFL	FSS returns control of tower frequencies and lights	GEN	TAR	terminal area surveillance radar	ICAO
FRWF	forecast wind factor	NWS	TARND	turn around	ATC
FRZ	freeze	NWS	TARS	terminal automated radar services	GEN
FRZLVL	freezing level	NWS	TARS	Tethered Aerostat Radar System	GEN
FRZN	frozen	NWS	TAS	true air speed	GEN
FSAS	flight service automation system	PHAK	TASR	terminal area surveillance radar	GEN
FSDO	Flight Standards District Office	GEN	TATCA	termical air traffic control automation	PHAK
FSDPS	flight service data processing systen	PHAK	TAVT	termial airspace visulization tool	PHAK
FSL	full stop landing	ICAO	TAWOG	travel arrangements without government expense	GEN
FSM	flight schedule monitor	ATC	TAWS	terrain awareness and warning system.
FSNFO	Flight Standards National Field Office	GEN	TAX	taxi or taxiing	ICAO
FSP	flight strip printer	GEN	TB	turbulence (PIREP only)	ATC
FSEP	facility/service/equiptment profile	PHAK	TBJT	turbojet	GEN
FSP	Flight strip printer	PHAK	TC	time check	ATC
FSPD	freeze speed parameter	PHAK	TC	tropical cyclone	ICAO
FSS	Flight Service Station	ICAO	TCA	terminal control area	GEN
FSSA	flight service station automated service	PHAK	TCA	tactical customer advocate	ATC
FST	first	ICAO	TCAS	traffic alert and collision avoidance system	GEN
FSTS	federal secure telephone service	PHAK	TCACCIS	transportaion coordinator automated command and control information system	PHAK
FSTD	flight simulation training device.		TCC	DOT transportation computer center	PHAK
FSYS	flight service station equipment system	PHAK	TCCC	tower control computer complex	PHAK
FT	feet	ICAO	TCE	Tone control equiptment	PHAK
FT	filing time	GEN	TCF	Traffic Flow Management Convective Forecast Product	ATC
FT	foot	GEN	TCH	threshold crossing height	ICAO
FTAR	following transmitted as received (message handling)	GEN	TCHD	threshold crossing height downwind	GEN
FTD	flight training device.		TCHU	threshold crossing height upwind	GEN
FTHR	farther or further	GEN	TCNTL	trans-continental	GEN
FTHRD	feathered	ATC	TCLT	tentatice calculated landing time	PHAK
FTS	Federal Telecommunications System	GEN	TCO	telecommunications certifications officer	PHAK
FTS2000	Federal Telecommunications System 2000	PHAK	TCOM	terminal communications	GEN
FU	smoke	METAR	TCP	transfer of control point	ATC
FUS	fuctional units or system	PHAK	TCS	tower communications system	PHAK
FURN	furnish	GEN	TCU	towering cumulus	NWS
FV	forward visibility (miles)	ATC	TD	Touchdown	ATC
FVFP	filed VFR flight plan	ATC	TD	transmitter distributor	GEN
FW/SIFR	fixed wing special IFR	GEN	TDA	Today	GEN
FW/SVFR	fixed wing special VFR	GEN	TDEL	time delay	GEN
FWA	flight watch area	GEN	TDLS	Terminal Data Link System	GEN
FWC	Fleet Weather Central	NWS	TDMUX	time division data multiplexter	PHAK
FWCS	flight watch control station	GEN	TDO	Tornado	ICAO
FWD	forward	GEN	TDOP	Time Dilution of Precision	ATC
FWDC	forward collect	GEN	TDWR	Terminal Doppler Weather Radar	ATC
FWP	flight watch point	GEN	TDY	temporary duty	GEN
FWRNG	fire warning	GEN	TDZ	touchdown zone	ICAO
FWS	flight watch specialist	GEN	TDZE	touchdown zone elevation	ATC
FWU	flight watch unit	GEN	TDZL	touchdown zone light (system)	GEN
FYI	for your information	GEN	TDZLG	touchdown zone lights	PHAK
FZ	supercooled/freezing	METAR	TEC	tower en route control	ATC
FZDZ	freezing drizzle	METAR	TECA	tower en route control area	ATC
FZFG	freezing fog	METAR	TECR	technical reason	ICAO
FZRA	freezing rain	METAR	TEL	telecommunications	GEN
FZRANO	freezing rain sensor not available	METAR	TEL	Telephone	ICAO
G	Green	ICAO	TELAU	Teleautograph	GEN
G	gusts reaching (knots) (weather reports only)	NWS	TELCO	telephone company	GEN
G/A	ground to air	ICAO	TELCON	telephone conference	GEN
G/A/G	ground to air and air to ground	ICAO	TELEX	telephone exchange	GEN
GA	general aviation	ICAO	TELMS	telecommunications managment systems	PHAK
GA	glide angle	GEN	TELRY	telegraph reply	GEN
GA	Go ahead, resume sending (to be used in AFS as a procedure signal)	ICAO	TEMP	Temperature	GEN
GAA	general aviation activity	PHAK	TEMPO	temporary	ICAO
GAAA	general aviation district office	PHAK	TEND	Trend	ICAO
GADO	General Aviation District Office	GEN	TERPS	terminal instrument procedures	GEN
GALS	gallons	ATC	TET	Tetrahedron	GEN
GBA	give better address	GEN	TF	terrain following	GEN
GBAS	ground−based augmentation system	ICAO	TFAC	to facility	PHAK
GBL	government bill of lading	GEN	TFC	traffic	ICAO
GBR	give better reference	GEN	TFMS	traffic flow management system	ATC
GC	ground control	GEN	TFR	temporary flight restriction	GEN
GCA	ground control approach	ICAO	TFRCD	traffic received	ATC
GCI	ground control intercept	GEN	TFZ	traffic zone	GEN
GCO	ground communication outlet	ATC	TGL	touch and go landing	ICAO
GDP	ground delay program	ATC	TGS	taxiing guidance system	ICAO
GDPGM	Ground Delay Program	ATC	TH	threshold	PHAK
GEN	general	GEN	THD	Thunderhead	NWS
GENOT	general notice	GEN	THDR	Thunder	NWS
GEO	geographic	GEN	THK	Thick	NWS
GEO	Geographic Satellite	AIM	THL	Takeoff Hold Lights	AIM
GEOREF	geographical reference	GEN	THLD	Threshold	GEN
GES	ground earth station	ICAO	THN	Thin	NWS
GHZ	gigahertz	GEN	THR	threshold	ICAO
GIC	GPS Integrity Channel	ATC	THRFTR	Thereafter	GEN
GICG	glaze icing	NWS	THRU	through	ICAO
GIS	geographic information system	PHAK	THRUT	Throughout	GEN
GLD	glider	ICAO	THSD	Thousand	GEN
GLDR	glider	GEN	THTN	threaten	GEN
GLFALSK	Gulf of Alaska	NWS	THU	Thursday	ICAO
GLFCAL	Gulf of California	NWS	TIBA	Traffic information broadcast by aircraft	ICAO
GLFMEX	Gulf of Mexico	NWS	TIBS	Telephone Information Briefing Service	AIM
GLFSTLAWR	Gulf of St. Lawrence	NWS	TIL	until	GEN
GLONASS	global navigation satellite system	ICAO	TIMS	telecommunications information managment system	PHAK
GLONASS	Global orbiting navigation satellite system	ICAO	TINOP	transponder inoperative	ATC
GLS	GBAS Landing System	ICAO	TIP	until past	ATC
GMC	Ground movement chart (followed by name/title)	ICAO	TIPS	terminal information processing system	GEN
GMT	Greenwich Mean Time	GEN	TIS	Traffic Information Service	AIM
GNAS	general national airspace system	PHAK	TIS−B	Traffic Information Service−Broadcast	AIM<
GND	ground	ICAO	TKOF	take-off	ICAO
GNDCK	ground check	ICAO	TL	Taxi lane	PHAK
GNDFG	ground fog	NWS	TLM	Telemetry	ATC
GNSS	global navigation satellite system (in general)	ICAO	TLRNC	tolerance	GEN
GNSSP	Global navigation satellite system panel	AIM	TLS	Transponder Landing System	AIM
GNTR	generator	GEN	TLTP	too long to print	GEN
GOES	geostationary operational environmental satellite	PHAK	TLWD	tailwind	ATC
GOESF	GOES feed point	PHAK	TM	time (PIREP only)	ATC
GOEST	GOES terminal eqiptment	PHAK	TM	traffic management	ATC
GOV	Governor	GEN	TMA	terminal control area	ICAO
GOVT	government	GEN	TMA	traffic managment advisor	PHAK
GP	glide path	ICAO	TM&O	telecommunications managment and operations	PHAK
GPA	glide path angle	ICAO	TMC	traffic managment coordinatior	PHAK
GPI	ground point of intercept	ATC	TMC/MC	traffic managment coordinatior/military coodinator	PHAK
GPRA	goverment performance results act	PHAK	TMCC	terminal information processing systems: Traffic Managment computer complex	PHAK
GPS	global positioning system	ICAO	TMF	Traffic managment facility	PHAK
GPWS	ground proximity warming system	PHAK	TML	television mucrowave link	PHAK
GQA	get quick answer	GEN	TMLT	television microwave link terminal	PHAK
GR	hail (greater than 3/4”)	METAR	TMPA	traffic management program alert	ATC
GRAD	gradient	NWS	TMPRY	temporary	GEN
GRADE	graphical airspace design envrionment	PHAK	TMS	Traffic managment systems	PHAK
GRADU	gradual	ICAO	TMSPS	traffic managment program alert	PHAK
GRASS	grass landing area	ICAO	TMT	transmit	GEN
GRBL	garble	GEN	TMU	traffic managment unit	PHAK
GRBNKS	Grand Banks	NWS	TMW	tomorrow	GEN
GRDL	gradual	NWS	TNA	turn altitude	ICAO
GRI	Group Repetition Interval	AIM	TNAV	terminal navigational aids	PHAK
GRID	grid point values of processed meteorological data	ICAO	TNDCY	tendency	GEN
GRTLKS	Great Lakes	NWS	TNGT	tonight	GEN
GRVL	gravel	ICAO	TNH	turn height	ICAO
GS	glide slope	GEN	TNTV	tentative	GEN
GS	Ground stop	ATC	TO	travel order	GEN
GS	Ground speed	ATC	TOC	to be continued	GEN
GS	snow pellets/small hail (less than 1/4”)	METAR	TOC	top of climb	ICAO
GSA	General Services Administration	GEN	TOD	time of delivery	GEN
GSD	Geographical Situation Display	AIM	TODA	take-off distance available	ICAO
GSDO	General Safety District Office	GEN	TOF	Time of flight	PHAK
GSE	ground support equiptment	PHAK	TOFMS	time of flight mass spectrometer	PHAK
GSI	General safety inspector	GEN	TOG	take-off gross weight	GEN
GSTS	Gusts	NWS	TOP	cloud top	NWS
GSTY	gusty	NWS	TOPS	telecommunications ordering and pricing systems	PHAK
GTC	gain time control	ATC	TOR	time of receipt	GEN
GTCL	Great Circle	GEN	TOR	traffic on request	ATC
GSD	Geopraphical situation display	AIM	TORA	take-off run available	ICAO
GTR	greater	GEN	TOT	time of transmission	GEN
GUND	Geoid undulation	ICAO	TOVC	top of overcast	NWS
GUS	ground uplink system	AIM	TP	turning point	ICAO
GV	ground visibility	NWS	TP	type aircraft (PIREP only)	ATC
GVG	giving	GEN	TPP	United States Terminal Procedures Publication
GVH	government vehicle	GEN	TPA	traffic pattern altitude	ATC
GWT	gross weight	GEN	TPG	topping	NWS
H	non directional radio homing beacon (NBD)	PHAK	TPP	Terminal Procedures Publications	AIM
H24	continuous 24-hour service	ICAO	TR	track	ICAO
HAA	height above airport	GEN	TR	VFR low altitude training routes	GEN
HADA	Hawaiian Defense Area	GEN	TRA	temporary reserved airspace	ICAO
HADD	Hawaiian Air Defense Division	GEN	TRACAB	terminal radar approach control in tower cab	GEN
HADIZ	Hawaiian Air Defense Identification Zone	GEN	TRACON	terminal radar approach control facility	GEN
HAL	height above landing	GEN	TRAD	terminal radar	GEN
HANG	Hawaiian Air National Guard	GEN	TRAN	transient	ATC
HAPI	holding as previously instructed	ATC	TRANS	transmit or transmitter	ICAO
HARS	hazardous area reporting service	ATC	TRB	transportaion research board	PHAK
HAT	height above touchdown	GEN	TRBL	trouble	GEN
HAZ	hazard	GEN	TRCV	tri-color visual approach slope indicator	GEN
HAZMAT	hazardous material	ICAO	TRG	training	ICAO
HB	homing beacon	ATC	TRIB	tributary	NWS
HBN	hazard beacon	ICAO	TRK	track	GEN
HCAP	high capacity carriers	PHAK	TRLVL	transition level	ICAO
HCVIS	high clouds visible	NWS	TRML	terminal	GEN
HDATZ	high density traffic zones	ATC	TRMT	terminate	GEN
HDF	high frequency direction finding station	ICAO	TRNG	Training	GEN
HDFRZ	hard freeze	NWS	TRNSP	Transport	GEN
HDG	heading	ICAO	TROF	Trough	NWS
HDME	NDB with distance measuring equiptment	PHAK	TROP	Tropopause	NWS
HDOP	Horizontal Dilution of Precision	ATC	TRPCD	tropical continental (air mass)	NWS
HDSVLY	Hudson Valley	NWS	TRPCL	Tropical	NWS
HDTA	high density traffic airport	GEN	TRPLYR	trapping layer	NWS
HDWND	headwind	ATC	TRRN	Terrain	GEN
HDQ	FAA headquarters	PHAK	TRSA	terminal radar service area	GEN
HEAD	Head of State status	ICAO	TRSN	Transition	GEN
HEL	helicopter	ICAO	TRTD	Treated	GEN
HELI	heliport	GEN	TS	team supervisor	GEN
HEMS	Helicopter Emergency Medical Services	AIM	TS	Thunderstorm	METAR
HF	high frequency	GEN	TS	transmitter station	GEN
HFR	hold for release	ATC	TSA	Transportation Security Administration	GEN
HGT	height	ICAO	TSATLC	Trans-Atlantic	GEN
HH	NBD 2kw or more	PHAK	TSEC	terminal secondary radar beacon	GEN
HHE	household effects	GEN	TSFR	Transfer	GEN
HI	high	NWS	TSGR	thunderstorm with hail	METAR
HIALS	high intensity approach light system	GEN	TSGS	thunderstorm with small hail	METAR
HIBAL	high altitude balloon	GEN	TSMNO	transmitting capability out of service	GEN
HIEAT	highest temperature equaled for all time	NWS	TSMOK	transmitting capability returned to service	GEN
HI-EFAS	high altitude EFAS	PHAK	TSNO	thunderstorm information not available	METAR
HIEFM	highest temperature equaled for the month	NWS	TSNT	Transient	GEN
HIESE	highest temperature equaled so early	NWS	TSO	technical standard order	GEN
HIESL	highest temperature equaled so late	NWS	TSP	telecommunications service priority	PHAK
HIFOR	high level forecast	NWS	TSPAC	Trans-Pacific	GEN
HIRIV	how will arrival report be filed concerning	ATC	TSPL	thunderstorm with ice pellets	METAR
HIRL	high intensity runway lights	GEN	TSR	telecomunications service request	PHAK
HITMP	highest temperature	NWS	TSRA	thunderstorm with rain	METAR
HIWAS	hazardous inflight weather advisory service	GEN	TSSA	thunderstorm with duststorm or sandstorm	METAR
HIXAT	highest temperature exceeded for all time	NWS	TSSN	thunderstorm with snow	METAR
HIXFM	highest temperature exceeded for the month	NWS	TSTM	thunderstorm	NWS
HIXSE	highest temperature exceeded so early	NWS	TT	teletypewriter	GEN
HIXSL	highest temperature exceeded so late	NWS	TTS	teletype switching facilities	GEN
HJ	sunrise to sunset	ICAO	TTY	teletypewriter station	GEN
HLDG	holding	ICAO	TUE	Tuesday	ICAO
HLF	half	GEN	TURB	turbulence	ICAO
HLP	heliport	ICAO	TURBC	turbulence	NWS
HLSTO	hailstones	NWS	TURBT	turbulent	NWS
HLTP	hilltop	NWS	T-VASIS	T visual approach slope indicator system	ICAO
HN	sunset to sunrise	ICAO	TVL	travel	GEN
HND	hundred	GEN	TVOR	terminal VOR	ICAO
HNGR	hangar	GEN	TVOR	very high frequency terminal omnirange station
HO	service available to meet operational requirements	ICAO	TW	taxiway	PHAK
HOL	holiday	GEN	TWD	toward	GEN
HOP	handoff point	ATC	TWEB	transcribed weather broadcast	GEN
HOP	helicopter operations	GEN	TWI	twilight	GEN
HOSP	hospital aircraft	ICAO	TWIB	Terminal Weather Information for Pilots system	AIM
HOW	handover word	ATC	TWR	aerodrome control tower	ICAO
HOV	High occupancy vehical	PHAK	TWR	tower	GEN
HP	holding pattern	GEN	TWRG	towering	NWS
HPA	hectopascal	ICAO	TWS	radar track while scan	ATC
HQ	headquarters	GEN	TWX	teletypewriter exchange service	GEN
HR	here	GEN	TWY	taxiway	ICAO
HR	hour	ICAO	TWYL	taxiway link	ICAO
HRR	Helicopter Rapid Refueling Procedures	AIM	TXG	taxiing	ATC
HRZN	horizon	GEN	TXL	taxilane	ICAO
HS	service available during scheduled operations	ICAO	TXT	Text	ICAO
HSI	horizontal situation indicators	PHAK	TYP	type aircraft	ICAO
HTN	heterodyne	GEN	TYPH	typhoon	ICAO
HTR	heater	GEN	TYPNO	teletypewriter communications out of service	GEN
HUD	head-up display		TYPOK	teletypewriter communications returned to service	GEN
HUD	Housing and urban development	PHAK	U	Intensity unknown (weather reports only)	NWS
HUM	humanitarian mission	ICAO	UA	routine PIREP	ATC
HURCN	hurricane	ICAO	UA	unable to approve arrival for the time specified	ATC
HUREP	hurricane report	NWS	UAB	until advised by	ATC
HV	high voltage	GEN	UAC	upper area control center	ICAO
HVDF	high and very high frequency direction finding stations	ICAO	UAG	upper atmosphere geophysics	NWS
HVY	heavy	ICAO	UAR	upper air route	ICAO
HWAS	hazardous in flight weather advisory	PHAK	UAS	unmanned aircraft system	ICAO
HWVR	however	GEN	UAT	until advised by the tower	ATC
HWY	highway	GEN	UAV	Unmanned Aerial Vehicle	AIM
HX	high index	NWS	UCDWN	until cleared down	ATC
HX	no specific working hours	ICAO	UCLT	until cleared to land by the tower	ATC
HYD	hydraulic	GEN	UD	unable to approve departure for the time specified	ATC
HYDRO	hydrographic	GEN	UDDF	up and down drafts	NWS
HYR	higher	ICAO	UDF	ultra high frequency direction finding station	ICAO
HZ	haze	METAR	UERE	User Equivalent Range Error	ATC
Hz	hertz	GEN	UFA	until further advised	GEN
IA	indirect access	PHAK	UFN	until further notice	GEN
I/AFSS	international AFSS	PHAK	UFO	unidentified flying object	GEN
I/IFR	intermittent instruments	ATC	UHA	unable higher altitude	ATC
IAARC	International Administrative Aeronautical Radio Conference	GEN	UHDODT	unable higher due opposite direction traffic	ATC
IAATCD	if authorized by ATC, DME may be used	ATC	UHDSDT	unable higher due same direction traffic	ATC
IAC	instrument approach chart (followed by name/title)	ICAO	UHDT	unable higher due traffic	ICAO
IAF	initial approach fix	ICAO	UHDT	unable higher due traffic	ICAO
IAO	in and out of clouds	ICAO	UHF	ultra high frequency	ICAO
IAP	instrument approach procedure	ICAO	UIC	upper information center	ICAO
IAPA	instrument appraoch procedures automation	PHAK	UIR	upper flight information region	ICAO
IAR	intersection of air routes	ICAO	ULDT	unable lower due traffic	ATC
IAS	indicated air speed	ATC	ULR	untra long range	ICAO
IAP	Instrument appraoch procedure	AIM	UM	unable to maintain	ATC
IATA	International Air Transport Association	GEN	UN	Unable	GEN
IATSC	International Aeronautical Telecommunications Switching Center	GEN	UNA	Unable	ICAO
IAW	in accordance with	GEN	UNAP	unable to approve	ICAO
IAWP	initial approach procedures		UNAPV	unable to approve	GEN
IBASF	intervals between aircraft in stream type formation	ATC	UNAR	unable to approve altitude requested	ATC
IBN	identification beacon	ICAO	UNATNDD	unattended	GEN
IBND	inbound	ATC	UNAVBL	unavailable	GEN
IC	ice crystals (weather reports only)	METAR	UNCC	unable to contact company radio	ATC
IC	icing (PIREP only)	ATC	UNDLD	undelivered	GEN
ICAO	International Civil Aviation Organization	GEN	UNEC	unnecessary	GEN
ICD	Interface Control Document	ATC	UNHRD	unheard	GEN
ICG	icing	NWS	UNID	unidentified	GEN
ICGIC	icing in clouds	NWS	UNKN	unknown	GEN
ICGICIP	icing in clouds and precipitation	NWS	UNL	unlimited	ICAO
ICGIP	icing in precipitation	NWS	UNLGTD	unlighted	GEN
ICSS	international communications switching systems	PHAK	UNMKD	unwarked	PHAK
ID	identify or identifier	ICAO	UNMON	unable to monitor	GEN
IDAT	interfacility data	GEN	UNMON	unmonitored	ATC
IDENT	identification	ICAO	UNMNT	unmonitored	PHAK
IDP	individual development plan	GEN	UNOFFL	unofficial	GEN
IF	intermediate approach fix	ICAO	UNRDBL	unreadable	GEN
IF	intermediate fix	GEN	UNREL	unreliable	ICAO
IFAMP	if approach missed proceed	ATC	UNRELBL	unreliable	GEN
IFCP	interfacility comminications processor	PHAK	UNRR	unable to approve route requested	ATC
IFDS	interfacility comminications processor	PHAK	UNRSTD	unrestricted	GEN
IFEA	in flight emergency assistance	PHAK	UNSATFY	unsatisfactory	GEN
IFF	identification friend/foe	ICAO	UNSBL	unseasonable	NWS
IFHOL	if holding	ATC	UNSKED	unscheduled	GEN
IFIM	International Flight Information Manual	GEN	UNSTBL	unstable	NWS
IFINS	if instrument conditions encountered	ATC	UNSTDY	unsteady	NWS
IFO	International Field Office	GEN	UNSTL	unsettle	NWS
IFO	interphone	GEN	UNTC	unable to establish contact	ATC
IFONO	interphone (service F) not operative	GEN	UNUSBL	unusable	GEN
IFORO	interphone (service F) resumed operation	GEN	UP	unknown precipitation	METAR
IFPFP	individual flight plans from this point	ATC	UPDFTS	up drafts	NWS
IFR	instrument flight rules	ICAO	UPDT	update	NWS
IFSS	International Flight Service Station	GEN	UPR	upper	NWS
IFSD	in flight shutdown		UPSLP	upslope	NWS
IFUN	if unable	GEN	UPSTRM	upstream	NWS
IFVLS	if flight visibility becomes less than	ATC	UQOT	unquote	GEN
IFVR	if visibility remains	ATC	URA	Unitform relocation assistance and real propert aquisition policies act of 1970	PHAK
IGA	international general aviation	ICAO	URAUZ	you are authorized	GEN
IGIA	Interagency Group on International Aviation	GEN	URG	urgent	GEN
IIA	if incorrect advise	GEN	URIZR	your recommendation is requested	GEN
IISD	if incorrect service direct	GEN	U.S.	United States	AIM
ILAS	instrument low approach	ATC	USA	U.S. Army	GEN
ILS	instrument landing system	ICAO	USAF	U.S. Air Force	GEN
ILSP	ILS-partial	GEN	USAFIB	U.S. Army Aviation Flight Information	GEN
ILS/PRM	Instrument Landing System/Precision Runway Monitor	AIM	USBL	usable	GEN
IM	inner marker	ICAO	USC	United states code	PHAK
IMAP	immediately after passing	ATC	USCG	U.S. Coast Guard	GEN
IMC	instrument meteorological conditions	GEN	USMC	U.S. Marine Corps	GEN
IMDT	immediate	NWS	USN	U.S. Navy	GEN
IMF	interrogation sign	GEN	USNO	United States Naval Observatory	ATC
InFO	Information For Operators	AIM	USNOF	United States NOTAM Office	GEN
IMG	immigration	ICAO	USNS	United States NOTAM System	GEN
IMI	Intensity unknown (weather reports only)	ICAO	USP	urgent special observation (weather reports only)	NWS
IMP	impracticable	GEN	UTA	upper control area	ICAO
IMPL	impulse	GEN	UTC	Coordinated Universal Time	ICAO
IMPR	improve	ICAO	UTCOK	Coordinated Universal Time Coordinate Check Completed	GEN
IMPT	important	GEN	UUA	urgent PIREP	ATC
IMT	immediate or immediately	GEN	UVV	upward vertical velocity	NWS
IN	inch	ICAO	UW	upwind	ATC
INA	initial approach	ICAO	UWNDS	upper winds	NWS
INADQT	inadequate	GEN	UWS	Urgent Weather SIGMET	AIM
INATS	interruption of air traffic services	GEN	V/VP	Vehical/pedestrian deviation	PHAK
INBD	inbound	ICAO	V	Variable (weather reports only)	NWS
INC	in clouds	ICAO	VA	victor airways	ATC
INC	incorporated	GEN	VA	volcanic ash	METAR
INCERFA	uncertainty phase code (alerting service)	ATC	Va	Design Manuvering speed
INCL	include	GEN	VAC	visual approach chart	ICAO
INCLV	inclusive	GEN	VAC	Visual approach chart (followed by name/title)	ICAO
INCOMP	incomplete	GEN	VACAPES	Virginia Capes	ATC
INCOR	incorrect	GEN	VADA	VFR arrival delay advisory	ATC
INCR	increase	GEN	VAL	in valleys	ICAO
INDC	indicate	GEN	VALE	voulentary airport low emission	PHAK
INDEF	indefinite	GEN	VAN	runway control van	ICAO
INDEFLY	indefinitly		VAPS	V/STOL approach system	GEN
INDUS	industrial	GEN	VAR	magnetic variation	ICAO
INF	inland navigation facility	GEN	VAR	visual-aural radio range	ICAO
INFO	information	ICAO	VAR	Volcanic Activity Reporting
INIT	initial training	GEN	VARN	Variation	GEN
INLD	inland	NWS	VASI	visual approach slope indicator	GEN
INOF	if not off	GEN	VASIS	visual approach slope indicator system	ICAO
INOP	inoperative	ICAO	Vb	design speed for maximum gust intensity.
INP	if not possible	GEN	VC	Vicinity	METAR/ TAF
INPR	in progress	ICAO	VC	Vicinity	METAR
INREQ	information request	GEN	Vc	design cruising speed.
INS	inertial navigation system	ICAO	VCFG	fog in vicinity	METAR
INSP	inspect	GEN	VCNTY	vicinity	GEN
INST	instrument	GEN	VCOA	Visual Climb Over the Airport
INSTA	instruments authorized	ATC	VCOT	VFR conditions on top	ATC
INSTA	interstate	ATC	VCTR	Vector	ATC
INSTBY	instability	NWS	VCY	vicinity	ICAO
INSTL	install	GEN	Vd	design diving speed.
INSTR	instruct	GEN	VDA	Vertical Descent Angle	AIM
INSTR	instrument	ICAO	VDF	very high frequency direction-finding station	ICAO
INSUF	insufficient scheduled time available	GEN	Vdf	demonstrated flight diving speed.
INSUF	unable to finish	GEN	VDOP	Vertical Dilution of Precision	ATC
INT	intersection	ICAO	VDP	visual descent point	GEN
INTCNTL	intercontinental	GEN	VER	Vertical	ICAO
INTCP	intercept	GEN	Vef	the speed at which the critical engine is assumed to fail during takeoff.
INTD	intend	GEN	VF	maintaining visual flight (Special VFR)	ATC
INTER	intermittent	ICAO	Vf	design flap speed.
INTFC	interference	GEN	Vfc	means maximum speed for stability characteristics.
INTL	international	ICAO	Vfe	maximum flap extended speed.
INTMD	intermediate	GEN	VFLT	visual flight	GEN
INTMT	intermittent	GEN	Vfto	final takeoff speed.
INTNS	intentions	GEN	VFPR	via flight planned route	ATC
INTR	interior	NWS	VFR	visual flight rules	ICAO
INTRG	interrogator	ICAO	VFRSA	VFR restrictions still apply	ATC
INTRMTRGN	Inter-Mountain Region	NWS	VFY	Verify	GEN
INTRP	interrupt	GEN	VGSI	visual glide slope indicator.
INTS	intense	NWS	Vh	maximum speed in level flight with maximum continuous power.
INTSF	intensify or intensifying	ICAO	VHF	very high frequency	ICAO
INTSFY	intensify	NWS	VIA	by way of	GEN
INTST	intensity	ICAO	VICE	instead/ versus	PHAK
INTVL	interval	GEN	VIP	very important person	ICAO
INTXN	intersection	GEN	VIP	visual integrated presentation	GEN
INVES	investigate	GEN	VIP	Video Integrator Processor	AIM
INVOF	in the vicinity of	ATC	VIS	visibility	ICAO
INVRN	inversion	NWS	VLCTY	Velocity	NWS
INVSTAR	investigate and report	GEN	Vle	means maximum landing gear extended speed.
IOC	nitial Operational Capability	AIM	VLF	very low frequency	GEN
IOVC	in overcast	NWS	VLFD	via low frequency direct	ATC
IP	initial point	ATC	VLNT	Violent	NWS
IP	instructor pilot	GEN	VLR	very long range	ICAO
IP/HHCL	initial point/H-hour control line	ATC	Vlo	maximum landing gear operating speed.
IPV	improve	GEN	Vlof	lift-off speed.
IR	ice on runway	NWS	VLY	Valley	NWS
IR	IFR military training route	GEN	VM	voice modulation	GEN
IRAC	Interdepartmental Radio Advisory Committee	GEN	VMC	visual meteorological conditions	ICAO
IRAD	inbound radial	ATC	Vmc	minimum control speed with the critical engine inoperative.
IRMP	information resource managment plan	PHAK	VMINI	Instrument flight minimum speed, utilized in complying with minimum limit speed requirements for instrument flight	AIM
IREG	irregular	GEN	Vmu	means minimum unstick speed.
IRN	Interface Revision Notices	ATC	Vmo	maximum operating limit speed.
IRU	Inertial reference unit	AIM	VNAV	vertical navigation (from TERPS-A1)	GEN
IS	island	GEN	Vne	never-exceed speed.
ISA	international standard atmosphere	ICAO	VNEI	Instrument flight never exceed speed, utilized instead of VNE for compliance with maximum limit speed requirements for instrument flight	AIM
ISB	independent sideband	ICAO	Vno	maximum structural cruising speed.
ISDN	intermin standard microwave landing system	PHAK	VNTSC	vol[e National trasportation system center	PHAK
ISMGR	Island Manager	GEN	VOD	via omni direct	ATC
ISMLS	interim standard microwave landing system	GEN	VOL	Volume	GEN
ISOL	isolate	GEN	VOLMET	meteorological information for aircraft in flight	ICAO
ITCK	issue time check	ATC	VON	virtual on net	PHAK
ITI	interactive terminal interface	PHAK	VOPR	voice operated relay	GEN
ITNRNT	itinerant	GEN	VOR	VHF omni-directional radio range	ICAO
ITRY	itinerary	GEN	VOR/DME	VOR and DME (collocated)	GEN
ITWS	.Integrated Terminal Weather System	AIM	VORTAC	VOR and TACAN (collocated)	ICAO
ITU	International Telecommunications Union	GEN	VOT	VOR airborne equipment test facility	ICAO
IVFRC	in VFR conditions	ATC	VOT	VOR test signal	GEN
IVRS	intrim voice response systen	PHAK	VOT	vorticity	GEN
IVSL	instantaneous vertical speed indicator.		VOT	VOR Test Facility	AIM
IW	inside wireing	PHAK	VOU	voucher	GEN
JAL	jet approach landing charts	GEN	VP/D	Vehical/pedestrian deviation	PHAK
JATO	jet assisted take-off	ATC	VR	veer	NWS
JAWYS	join airways	ATC	VR	VFR military training routes	GEN
J-BAR	jet runway barrier	ATC	Vr	rotation speed.
JCTN	junction	GEN	Vref	reference landing speed.
JFK	John F. Kennedy International Airport	AIM	VRB	variable	ICAO
JOUR	journeyman	GEN	VRBL	variable	GEN
JP	jet penetration	ATC	VRG	visual reference gate	GEN
JPAP	jet penetration approach	ATC	VRISL	Vancouver Island, BC	NWS
JTST	jet stream	ICAO	VRS	voice recording system	PHAK
JTSTR	jet stream	NWS	VRT MOTN	vertical motion	NWS
K	Cold (air mass)	NWS	VS	the stalling speed or the minimum steady flight speed at which the airplane is controllable.
Kbps	kilobits per sec	PHAK	VSA	by visual reference to the ground	ICAO
KC	kilocycles	GEN	VSB	visible	GEN
KEPOA	keep this office advised	GEN	VSBY	visibility	NWS
KFRST	killing frost	NWS	VSBYDR	visibility decreasing rapidly	NWS
KG	kilogram	GEN	VSBYIR	visibility increasing rapidly	NWS
KHZ	kilohertz	GEN	VSCS	Voice switching and control system	PHAK
KIAS	knots indicated airspeed	GEN	VSL	vessel	GEN
KM	kilometers	GEN	VSP	vertical speed	ICAO
KMH	kilometers per hour	ICAO	Vso	the stalling speed or the minimum steady flight speed in the landing configuration.
KPA	kilopascal	ICAO	Vs1	stalling speed or the minimum steady flight speed obtained in a specific configuration.
KT	knots	GEN	VSPI	visual glide path indicator	GEN
KVDT	keyboard video display terminal	PHAK	Vsr	reference stall speed.
KW	kilowatt	GEN	Vsro	reference stall speed in the landing configuration.
L	Left	ICAO	Vsr1	reference stall speed in a specific configuration.
L	Locator	ICAO	VSTOL	vertical/short take-off and landing	GEN
L	Logistics	GEN	VSW	speed at which onset of natural or artificial stall warning occurs.
L/MF	low/medium frequency	GEN	VTF	Vector to Final	AIM
LA	leased Service A/B system	ATC	VTOL	vertical take-off and landing	ICAO
LAA	local airport advisory	GEN	VTS	voice telecommunications system	PHAK
LAADR	low altitude arrival/departure routing	ATC	Vx	speed for best angle of climb.
LAAS	Local Area Augmentation System	ATC	Vy	speed for best rate of climb.
LAB	laboratory	GEN	V1	the maximum speed in the takeoff at which the pilot must take the first action (e.g., apply brakes, reduce thrust, deploy speed brakes) to stop the airplane within the accelerate-stop distance. V1 also means the minimum speed in the takeoff, following a failure of the critical engine at VEF, at which the pilot can continue the takeoff and achieve the required height above the takeoff surface within the takeoff distance.
LABRDR	labrador	NWS	V2	takeoff safety speed.
LABS	leased Service A/B system	ATC	V2min	minimum takeoff safety speed.
LABS	low altitude bombing system	GEN	VV	vertical visibility (indefinite ceiling)	METAR
LABSC	LABS GS-200 computer	PHAK	VVI	Vertical Velocity Indicator	AIM
LABSR	LABS remote equiptment	PHAK	VY	Speed for best rate of climb	AIM
LABSW	LABS switch system	PHAK	VYI	Instrument climb speed, utilized instead of VY for compliance with the climb requirements for instrument flight	AIM
LABHSO	land and hols short operation	PHAK	W	warm (air mass)	NWS
LADP	local airport deicing plan	ATC	W	west or western longitude	ICAO
LAHSO	Land and Hold Short Operations	AIM	W	White	ICAO
LAM	logical acknowledgement	ICAO	WA	AIRMET	NWS
LAN	inland	ICAO	WAAS	Wide Area Augmentation System	ICAO
LAN	local area network	PHAK	WAC	World aeronautical chart – ICAO 1:1 000 000(followed by name/title)	ICAO
LARCT	last radio contact	ATC	WAFC	world area forecast center	ICAO
LAT	latitude	ICAO	WAIOP	will accept, if offered, the position	GEN
LATA	local access and transport area	PHAK	WAN	wide area network	PHAK
LAWRS	Limited Aviation Weather Reporting Station	GEN	WARP	A device that provides real-time, accurate, predictive and strategic weather information presented in an integrated manner in the National Airspace System (NAS).
LB	left base	ATC	WB	Westbound	ICAO
LB	pounds (weight)	GEN	WBAR	wing bar lights	ICAO
LC	local control	GEN	WBND	Westbound	ATC
LCA	locally	ICAO	WBRBN	will be reported by NOTAM	GEN
LCL	local or locally	GEN	WBRH	Weather Bureau Regional Headquar− ters	GEN
LCN	local comminication network	PHAK	WBTS	Whereabouts	GEN
LCT	locate	GEN	WC	Work center	PHAK
LCTD	lighted	PHAK	WCA	wind correction angle
LCTMP	little change in temperature	NWS	WCLC	Watch check list completed	GEN
LD	long distance	GEN	WCP	weather comminications processor	PHAK
LDA	landing distance available	ICAO	WECO	western electric company	PHAK
LDA	localizer type directional aid	ATC	WED	Wednesday	PHAK
LDA/PRM	Localizer Type Directional Aid/Precision	AIM	WEF	with effect from effective from	PHAK
LDG	Runway Monitor	ICAO	WESCOM	western electric satellite communications	PHAK
LDI	landing direction indicator	ICAO	WDC-1	World Data Centers in Western Europe	NWS
LDIN	lead in lighting system	GEN	WDC-2	World Data Centers throughout rest of world	NWS
LEC	local exchange carrier	PHAK	WDI	wind direction indicator	ICAO
LEN	length	ICAO	WDLY	Widely	NWS
LETFO	letter follows	GEN	WDSPR	Widespread	GEN
LF	low frequency	GEN	WDSPRD	Widespread	NWS
LFC	laminar flow control	GEN	WEA	Weather	NWS
LFNT	low frequency intersection	GEN	WED	Wednesday	ICAO
LFR	low frequency radio range	GEN	WEF	With effect from, or effective from	ICAO
LFT	lift	NWS	WFO	Weather Forecast Office	GEN
LGA	LaGuardia Airport		WFP	Warm front passage	NWS
LGRNG	long range	NWS	WG	Working group	GEN
LGT	light or lighting	ICAO	WGS	World Geodetic System	ATC
LGTD	lighted	ICAO	WGS-84	World geodetic system 1984	ICAO
LGWV	long wave	GEN	WI	within	ICAO
LICOF	land lines communications facilities	GEN	WIBIS	will be issued	GEN
LIFR	low IFR (weather reports only)	NWS	WICA	while in control area	ATC
LIH	light intensity high	ICAO	WICZ	while in control zone	ATC
LIL	light intensity low	ICAO	WID	width or wide	ICAO
LIM	light intensity medium	ICAO	WIE	with immediate effect or effective immediately	ICAO
LIN	linearity	GEN	WILCO	will comply	GEN
LINCS	leasted interfacility NAS C	PHAK	WINT	winter	NWS
LIRL	low intensity runway edge lights	GEN	WINTEM	forecast upper wind and temperature for aviation	ICAO
LIS	logistics and inventory system	PHAK	WIP	work in progress	ICAO
LK	lake	NWS	WK	weak	GEN
LKLY	likely	GEN	WKDAY	weekday	GEN
LKTYP	like type	ATC	WKDAYS	monday-friday	PHAK
LL	landline	GEN	WKEND	weekend	GEN
LLWAS	low level wind shear alert system	GEN	WKN	weaken	GEN
LLWAS NE	Low Level Wind Shear Alert System Network Expansion		WL	will	GEN
LLWAS−RS	Low Level Wind Shear Alert System Relocation/Sustainment		WLAV	will advise	GEN
LLWS	low level wind shear	GEN	WMO	World Meteorological Organization	GEN
LLZ	localizer (not associated with ILS)	ICAO	WMS	Wide−Area Master Station	AIM
LM	locator middle	ICAO	WMSC	Weather Message Switching Center	GEN
L/MF	low or medium frequency.		WMSCR	Weather Message Switching Center Replacement	AIM
LM/MS	low/medium frequency		WND	wind	NWS
LMM	compass locator at ILS middle marker	GEN	WNW	west-north west	ICAO
LMT	limit	GEN	WNWRN	west-northwestern (weather reports only)	NWS
LMT	Local Mean Time	ICAO	WNWWD	west-northwestward (weather reports only)	NWS
LN	line	GEN	WO	Washington Office	GEN
LNAV	lateral navigation (from TERPS-A1)	GEN	WO	without	GEN
LND	Land	GEN	WP	waypoint	GEN
LNDG	landing	GEN	WPLTO	western plateau	NWS
LO	liaison officer	GEN	WPM	words per minute	GEN
LO	outer locator	ICAO	WPRT	waypoint report	ATC
LOA	letter of agreement	GEN	WPT	waypoint	ICAO
LOC	localizer	ICAO	WR	wet runway	NWS
LOCOR	local coordinator	GEN	WRA	Weather Reconnaissance Area	GEN
LOCID	location identifier	PHAK	WRC	well to right of course	ATC
LODISNAV	long distance navigation	GEN	WRM	warm	NWS
LOEAT	lowest temperature equaled for all time	NWS	WRMFNT	warm front	NWS
LOEFM	lowest temperature equaled for the month	NWS	WRNG	warning	NWS
LOESE	lowest temperature equaled so early	NWS	WRS	worse	GEN
LOESL	lowest temperature equaled so late	NWS	WRS	Wide−Area Ground Reference Station
LOI	letter of intent	PHAK	WS	SIGMET	NWS
LOM	compass locator at ILS outer marker	GEN	WS	weak signals	ATC
LONG	longitude	ICAO	WS	wind shear	ICAO
LONGL	longitudinal	GEN	WSCMO	Weather Service Contract Meteorological Observatory	GEN
LOP	line of position	GEN	WSHFT	wind shift	NWS
LORAC	long range accuracy	GEN	WSO	Weather Service Office	GEN
LORAN	long range air navigation system	GEN	WSOM	weather service operations manual	NWS
LOTMP	lowest temperature	NWS	WSFO	weather service forecast office	PHAK
LOXAT	lowest temperature exceeded for all time	NWS	WSMO	weather service meterological observatory	PHAK
LOXFM	lowest temperature exceeded for the month	NWS	WSO	weather service officer	PHAK
LOXSE	lowest temperature exceeded so early	NWS	WSP	weather system processor (replacement for LLWAS)	GEN
LOXSL	lowest temperature exceeded so late	NWS	WSR	wet snow on runway	NWS
LP	left traffic pattern	ATC	WSSF	National Weather Service Support Facility	GEN
LP	linear polarization	ATC	WSSU	National Weather Service Support Unit	GEN
LP	liquid propane	GEN	WST	Convective Significant Meteorological Information
LP	localizer performance without vertical guidance	GEN	WSTCH	wasatch range	NWS
LPV	localizer performance with vertical guidance	ICAO	WSW	west-south west	ICAO
LR	The last message received by me was .	ICAO	WSWRN	west-southwestern (weather reports only)	NWS
LRA	landing rights airport	GEN	WSWWD	west-southwestward (weather reports only)	NWS
LRCO	limited remote comminications outlet	PHAK	WT	Weight	GEN
LRCOM	long range VHF/UHF communications	GEN	WTHR	weather	PHAK
LRG	large	GEN	WTR	Water	NWS
LRG	long range	GEN	WTR	well to right	ATC
LRNAV	long range navigation	PHAK	WTSPT	waterspout	NWS
LRR	long range rader	PHAK	WU	Western Union Telegraph Company	GEN
LRS	lake reporting service	GEN	WV	Wave	NWS
LS	left side	ATC	WV	wind at altitude (PIREP only)	ATC
LS	The last message sent by me was or last message was	ICAO	WW	severe weather forecast	NWS
LSQ	line squall	ICAO	WWW	World wide web	ICAO
LSR	loose snow on runway	NWS	WX	weather	ICAO
LST	Local Standard Time	GEN	WX	weather at altitude (PIREP only)	ATC
LT	turn left after take-off	ATC	WXCON	weather reconnaissance flight pilot report	NWS
LTAV	light and variable	GEN	WYAIO	will you accept, if offered, the position of	GEN
LTD	limited	ICAO	X	Cross	ICAO
LTF	local training flight	ATC	X	Obscured sky condition	NWS
LTFC	landing traffic	ATC	XBAR	Crossbar	ICAO
LTGCA	lightning cloud-to-air	NWS	XCP	Except	NWS
LTGCC	lightning cloud-to-cloud	NWS	XFSS	Auxiliary Flight Service Station	ATC
LTGCCCG	lightning cloud-to-cloud, cloud to ground	NWS	XH	special handling service for aircraft	GEN
LTGCG	lightning cloud-to-ground	NWS	XNG	Crossing	ICAO
LTGCW	lightning cloud-to-water	NWS	XPC	expect	NWS
LTGIC	lightning in clouds	NWS	XPLOS	explosive	GEN
LTL	little	GEN	XREP	auxiliary report	GEN
LTLCG	little change	NWS	XS	atmospherics	ICAO
LTNG	lightning	NWS	XTAL	crystal	GEN
LTR	later	GEN	XTLK	cross talk	ATC
LTR	letter	GEN	XW	crosswind	ATC
LTT	landline teletypewriter	ICAO	XX	heavy (to qualify weather phenomena, e.g. XXRA – heavy rain)	ICAO
LTTR	latter	GEN	Y	Yukon Standard Time (time groups only)	NWS
LUAW	Line Up and Wait	AIM	YCZ	yellow caution zone (runway lighting)	ICAO
LV	leaving	GEN	YD	Yards	ICAO
LV	light and variable	ICAO	YDA	Yesterday	GEN
LVE	leave or leaving	ICAO	YES	Yes (affirmative)	ICAO
LVG	leaving	ATC	YKN	Yukon	NWS
LVL	level	ATC	YL	approach light lane	ATC
LVO	low visibility operations	GEN	YLSTN	Yellowstone	NWS
LVLOF	level off	ATC	YMSG	your message	GEN
LWR	lower	GEN	YMSGD	your message date	GEN
LX	low index	NWS	YR	Your	ICAO
LYR	layer or layered or layers	NWS	Z	Greenwich Mean Time	GEN
LZ	Landing Zone	AIM	Z	jet terminal area	ATC
M	in RVR indicates visibility less than lowest reportable sensor value (e.g. M600)	METAR	ZI	zonal index	NWS
M	in temperature field means “minus” or below zero	METAR	ZI	zone of interior	NWS
			ZM	Z marker (VHF station location marker)	GEN
			ZRNO	freezing rain information not available (weather reports only)	NWS