Decode

Section 2. Encode

EXPLANATION OF CODES

GEN - Indicates general aeronautical usage.

NWS - Indicates National Weather Service and aeronautical weather usage.

ATC - Indicates Air Traffic Control usage.

ICAO - Indicates International Civil Aviation Organization usage. International messages should use these.

METAR/TAF - Indicates ICAO weather usage.

A

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

B

Definition	Contraction	Usage
back course	BC	GEN
back course marker	BCM	GEN
back taxiing	BT	ATC
backing	BCKG	NWS
backup emergency communication	BUEC	GEN
backup interceptor control	BUIC	ATC
Bahama Route	BR	ATC
balance	BAL	GEN
balloon	BLN	GEN
baroclinic or baroclinic prognosis	BACLIN	NWS
barometer	BRM	NWS
barotropic or barotropic prognosis	BATROP	NWS
base leg	B	ATC
base of overcast	BOVC	NWS
Base Operations Office	BASOPS	GEN
basic meteorological services	BMS	NWS
beach	BCH	NWS
beacon	BCN	ICAO
beacon data (digitized)	BDAT	ATC
bearing	BRG	GEN
become	BCM	GEN
becoming (expected between 2 digit beginning hour and 2 digit ending hour)	BECMG	TAF
Before	BFR	GEN
before dark	BFDK	NWS
before encountering IFR conditions	BIFR	ATC
before proceeding on course	BPOC	ATC
began or begin	BGN	GEN
begin or beginning descent	BGND	ATC
begin standard refuel orbit	BSRO	ATC
beginning climb	BC	ATC
beginning of precipitation (time in minutes) (weather reports only)	B	NWS
beginning procedure turn	BPT	ATC
beginning standard holding procedure	BSHP	ATC
beginning standard range approach	BSRAP	ATC
beginning straight-in approach	BSIAP	ATC
Behind	BHND	GEN
Below	BLO	GEN
Below	BLW	ICAO
below all clouds	BAC	ATC
below clouds	BLO	ICAO
beneath	BNTH	GEN
Bering Standard Time (time groups only)	B	NWS
Berkshire	BRKSHR	NWS
Bermuda	BDA	NWS
Better	BTR	GEN
Between	BTN	ICAO
Between	BTWN	NWS
between layers	BTL	ICAO
Beyond	BYD	GEN
bids accepted for the following vacancies	BAFVC	GEN
bids solicited	BDSLD	GEN
bids solicited as follows	BSAF	GEN
bird sweep completed	BSC	ATC
Black Hills	BLKHLS	NWS
Blanket	BLKT	NWS
Blizzard	BLZD	NWS
Block	BLX	ATC
Blowing	BL	METAR
blowing dust	BLDU	METAR
blowing sand	BLSA	METAR
blowing snow	BLSN	METAR
blowing spray (weather reports only)	BY	METAR
Blue	B	GEN
Bomber	BMBR	GEN
Bombing	BOMB	GEN
Border	BDR	GEN
Bound	BND	GEN
Boundary	BDRY	ATC
boundary	BNDRY	ICAO
braking	BRKG	ICAO
braking action	BA	ICAO
braking action good	BRAG	GEN
braking action medium	BRAM	GEN
braking action nil	BRAN	GEN
braking action poor	BRAP	GEN
branch	BR	GEN
break	BRK	NWS
breaks in higher overcast	BRKHIC	NWS
breaks in overcast	BINOVC	NWS
brief	BRF	NWS
bright	BRGT	GEN
bright radar indicator tower equipment	BRITE	GEN
British Columbia	BC	NWS
broadcast	BCST	ICAO
broadcast requested	BCREQ	ATC
broadcast station	BCSTN	GEN
broken	BKN	METAR
build	BLD	NWS
building	BLDG	ICAO
buildup	BLDUP	NWS
bulletin	BUL	GEN
bureau	BUR	GEN
business	BUS	GEN
buzzer (radar)	BZR	GEN
by visual reference to the ground	VSA	ICAO
by way of	VIA	GEN
bytes per second	BPS	GEN

C

Definition	Contraction	Usage
calibration	CLBR	ICAO
calibration performance monitoring equipment	CPME	ATC
Call sign	CS	ICAO
Calling	CLG	ICAO
Canada	CAN	NWS
Canadian	CNDN	NWS
Canadian Airspace Reservation Unit	CARU	GEN
Canadian Armed Force	CANFORCE	GEN
Canadian Armed Forces Transport Command	CAM	GEN
Canadian Forces Air Defense Command	CFADC	GEN
Canadian NORAD Region	CANR	GEN
Canadian NOTAM	CANOT	GEN
cancel	CNCL	NWS
cancel	CNL	GEN
cancel approved arrival	CXA	ATC
cancel approved departure	CXD	ATC
cancel flight plan	CNLFP	ATC
cancel IFR clearance previously given	CIFR	ATC
cancel IFR flight plan	CIFP	ATC
cancel VFR flight plan	CVFP	ATC
candela	CD	ICAO
capable	CPBL	GEN
capacity	CPTY	GEN
captain	CAPT	GEN
carbon copy	CC	GEN
Caribbean	CARIB	NWS
carryover from previous log	CFPL	ATC
cascades	CASCDS	NWS
catalogue number	CANO	GEN
category	CAT	ICAO
category	CTGY	NWS
cathode ray tube	CRT	GEN
Catskills	CTSKLS	NWS
caution	CTN	GEN
caution advised until further notice	CAUFN	GEN
ceiling	CIG	NWS
celestial	CLST	ATC
celestial navigation	CELNAV	GEN
celsius	C	GEN
center	CNTR	GEN
center clearance delivered	B	ATC
centerline	CNTRLN	GEN
centimeter	CM	ICAO
central	CNTRL	GEN
central altitude reservation function	CARF	GEN
Central Computer Complex	CCC	GEN
central flow weather service unit	CFWSU	GEN
Central North Pacific	CENPAC	ATC
Central Region, FAA	ACE	GEN
Central Standard Time (time groups only)	C	NWS
central weather service unit	CWSU	GEN
centre (runway ID)	C	ICAO
centre line	CL	ICAO
certificate	CERT	GEN
certification	CERTIF	GEN
certify	CRTFY	GEN
chance	CHC	NWS
change	CHG	GEN
change frequency to	CF	ICAO
change of appointing office	CAO	GEN
change to approach control or changing to approach control	CAC	ATC
change to center control or changing to center control	CTCC	ATC
change weight manifest	CWM	GEN
changeover	CHOV	ATC
changeover point	COP	GEN
changing over	CHGO	ATC
channel	CH	ICAO
channel	CHNL	GEN
chapter	CHAP	GEN
characteristic	CHARC	GEN
charge	CHRG	GEN
charter	CHTR	GEN
check	CK	ICAO
check area airports	CARA	GEN
check okay	CHOK	GEN
chemicals	CHM	GEN
Chesapeake	CHSPK	NWS
chief controller	CCTLR	GEN
Chief, Airport District Office	CADO	GEN
circle	CRC	GEN
circling (approach and landing charts)	C	ATC
circling guidance light	CGL	ICAO
circuit	CKT	GEN
circuit line up	CLU	GEN
circuit notice	CIRNOT	GEN
circular polarization	CP	GEN
circulate	CRLC	GEN
circumnavigate	CIRNAV	ATC
cirrocumulus	CC	NWS
cirrostratus	CS	NWS
cirrus	CI	NWS
City (or County) Civil Defense Director at____	CCD	GEN
civil	CIV	ICAO
civil air carrier turbojet	CACT	GEN
Civil Air Patrol	CAP	GEN
civil defense	CD	GEN
civil engineer	CENGR	GEN
civil reserve air fleet	CRAF	GEN
clarify	CFY	GEN
Class A Airspace	CAAS	ATC
Class B airspace	CBAS	ATC
Class B surface area	CBSA	ATC
Class C airspace	CCAS	ATC
Class C surface area	CCSA	ATC
Class D airspace	CDAS	ATC
Class D surface area	CDSA	ATC
Class E airspace	CEAS	ATC
Class E surface area	CESA	ATC
Class G airspace	CGAS	ATC
clears, or cleared to, or clearance	CLR	ICAO
clear above (PIREP only)	CA	ATC
clear air turbulence	CAT	GEN
clear and smooth	CLRS	NWS
clear of clouds	CCLDS	ATC
clear or scattered clouds and visibility greater than ten miles	CAVU	NWS
clear or scattered clouds and visibility greater than ten, remainder of report missing (weather reports only)	DCAVU	NWS
clear type of ice formation	CLA	ICAO
clearance	CLNC	GEN
clearance delivery	CD	GEN
clearance void if not off	CVINO	ATC
cleared as planned	CLRAP	ATC
cleared Customs	CCUS	GEN
cleared for approach	CFAP	ATC
cleared to fix	F	ATC
clearway	CWY	ICAO
climb	CLB	ATC
climb and cross	CATX	ATC
climb and cruise	CCRZ	ATC
climb at pilot s discretion	CAPD	ATC
climb en route	CER	ATC
climb immediately	CLBI	ATC
climb on course	COC	ATC
climb so as to cross	CSATX	ATC
climb so as to reach	CSATR	ATC
climb to and cross	CTAX	ATC
climb to and maintain	CTAM	ATC
climb to or climbing to	CMB	ICAO
climb well to right	CWTR	ATC
climb well to right of course	CWRC	ATC
clockwise	CLKWS	GEN
clockwise orbit	CLKOB	ATC
close of business	COB	GEN
close this office	CLOTO	GEN
closed	CLSD	ICAO
closing date	CLODA	GEN
closing station	CL	GEN
cloud	CLD	NWS
cloud and visibility OK	CAVOK	NWS
cloud base	BASE	GEN
cloud top	TOP	NWS
Coarse/Acquisition	C/A	ATC
coast	CST	NWS
Coast Guard	CG	GEN
Coast Guard Air Station	CGAS	GEN
Coast Guard LORAN Station	CGLS	GEN
coastal zone management	CZM	GEN
Cockpit voice recorder	CVR	ICAO
Code of Federal Regulations	CFR	GEN
cold (air mass)	K	NWS
cold front	CDFNT	NWS
cold front passage	CFP	NWS
collaborative convective forecast product	CCFP	ATC
collaborative decision making	CDM	ATC
collect	COLL	GEN
collision avoidance system	CAS	GEN
colon	CLN	GEN
combine	COMB	GEN
combined approach control/international station	CAP/IS	GEN
combined center/RAPCON	CERAP	GEN
combined station/center	CS/C	GEN
combined station/tower	CS/T	GEN
comma	CMA	GEN
Commander in Chief, North American Aerospace Defense Command	CINCNORAD	GEN
commence	CMNC	GEN
commercial	COML	GEN
commercial broadcasting station	BS	ICAO
commission	CMSN	GEN
common aviation weather subsystem	CAWS	NWS
common ICAO data interchange network	CIDIN	ICAO
Common IFR Room	CIFRR	GEN
common terminal radar approach control	CTRAC	GEN
common traffic advisory frequency	CTAF	ATC
communication	COM	ICAO
communications duty officer	CDO	GEN
communications equipment	CE	GEN
communications instructions for reporting vital intelligence sightings	CIRVIS	ATC
communications, navigation and surveillance	CNS	ICAO
compact	CMPCT	GEN
company	CO	GEN
compare	COMPR	GEN
compartment	COMPRT	GEN
compass locator	COMLO	GEN
compass locator at ILS middle marker	LMM	GEN
compass locator at ILS outer marker	LOM	GEN
complete	CMPLT	GEN
complete crew	CCRU	GEN
complete or completed or completion	CMPL	ICAO
complete power failure	CPF	GEN
completed procedure turn	COPT	ATC
complex	CMPLX	GEN
component	CMPT	GEN
composite flight data processing	CFAD	GEN
composite radar data processing	CRAD	GEN
composition	CMPSN	GEN
computer display channel	CDC	GEN
computerized voice reservation system	CVRS	ATC
concrete	CONC	ICAO
concurrently	CNCNT	GEN
condensation trails	CONTRAILS	NWS
condition	COND	ICAO
confidence	CONFDC	NWS
confidential	CONF	GEN
configuration	CONFIGN	GEN
configuration	CONFIG	ATC
confine	CFN	GEN
confirm	CFM	GEN
Confirm or I confirm	CFM	ICAO
confirming requisition follows	COREQ	GEN
congestion	CGSTN	GEN
connect	CNCT	GEN
consider	CSDR	GEN
considerable	CSDRBL	GEN
consistent	CNSTNT	GEN
consol beacon	CONSOL	GEN
CONSOLAN Facility	CONSO	GEN
consolidate	CSLDT	GEN
Consolidated NOTAM System	CNS	ATC
construction	CONST	ICAO
construction maintenance supervisor	CMS	GEN
contact	CTC	ICAO
contact approach control	CAC	ATC
contact center	CTCEN	ATC
contact center control	CTCC	ATC
continental (air mass)	C	NWS
continental control area	CCA	GEN
Continental Divide	CONTDVD	NWS
Continental NORAD Region	CONR	GEN
continue calling until	CONCA	ATC
continue(s) or continued	CONT	ICAO
continue to hold	CONTH	ATC
continuous	CONS	ICAO
continuous 24-hour service	H24	ICAO
continuous wave	CW	ICAO
contract	CONTR	GEN
control	CTL	ICAO
control area	CTA	ICAO
control area	CTLA	GEN
control boundary	CTLB	GEN
control zone	CTLZ	GEN
control zone	CTR	ICAO
controlled airspace	CTAS	ATC
controlled firing area	CFA	ATC
controller	CTLR	GEN
controller in charge	CIC	GEN
Controller-pilot data link communications	CPDLC	ICAO
Controllers Operations and Procedures Committee	COPCOM	GEN
convective	CNVTV	NWS
convene	CVN	GEN
converge	CNVG	GEN
conversion	CNVSN	GEN
convert	CNVRT	GEN
coordinate	COORD	GEN
Coordinated Universal Time	UTC	ICAO
Coordinated Universal Time Coordinate Check Completed	UTCOK	GEN
Coordinates	COORD	ICAO
coordination	CDN	ICAO
correct or corrected or correction	COR	GEN
corridor assignment	CORAS	ATC
counterclockwise	CCLKWS	NWS
counterclockwise orbit	CCLKOB	ATC
county	CO	GEN
coupled	CPD	GEN
course	CRS	GEN
course line	CL	ATC
cover	COV	ICAO
cover	CVR	GEN
crash locator beacon	CLBN	GEN
crash phone activated	CPA	GEN
crew chief	CRCHF	GEN
cross	X	ICAO
cross talk	XTLK	ATC
crossbar	XBAR	ICAO
crossing	XNG	ICAO
crosswind	XW	ATC
cruise	CRZ	ICAO
cruise and maintain	CRZAM	ATC
cruise well to right	CRZWTR	ATC
Cryptographic	CRYPTO	GEN
Crystal	XTAL	GEN
Cumuliform	CUF	ICAO
Cumulonimbus	CB	NWS
cumulonimbus mamma	CBMAM	NWS
Cumulus	CU	NWS
cumulus fractus	CUFRA	NWS
current flight plan	CPL	ICAO
Customs	CUST	ICAO
customs has been notified	CUSNO	GEN
Cyclic redundancy check	CRC	ICAO
Cyclogenesis	CYCLGN	NWS
Cyclonic	CYC	NWS
Cylinder	CYL	GEN

D

Definition	Contraction	Usage
Daily	DLY	GEN
Daily	DLY	ICAO
daily flight log	DFL	GEN
Dakotas	DKTS	NWS
damage	DMG	GEN
danger	DGR	GEN
danger	DNG	ICAO
danger area	D	ICAO
dangerous cargo	DGCGO	GEN
data link	DOLLY	GEN
Data link Automatic Terminal Information Service	D-ATIS	ICAO
Data link initiation capability	DLIC	ICAO
Data link VOLMET	D-VOLMET	ICAO
data terminal equipment	DTE	GEN
data transmission feature	DTF	GEN
data transmission request	DTR	GEN
date of birth	DOB	GEN
date time group	DTG	GEN
Davide J. Hurley ATC System Command Center	ATCSCC	GEN
daybreak	DABRK	NWS
daylight	DALGT	GEN
dead reckoning	DR	ATC
decelerate	DCLRT	ATC
decibel	DB	GEN
decision altitude	DA	ICAO
decision height	DH	ICAO
decommission	DCMSN	GEN
decrease	DCR	GEN
deep	DP	NWS
deepening	DPNG	NWS
defense	DEF	GEN
defense combat maneuvers	DCM	ATC
Defense Commercial Communications Office	DECCO	GEN
Defense Communications Agency	DCA	GEN
defense communications system	DCS	GEN
Defense Mapping Agency Aerospace Center	DMAAC	GEN
Defense Mapping Agency Hydrographic Center	DMAHC	GEN
Defense Nuclear Agency	DNA	GEN
Defense Readiness Conditions	DEFCON	GEN
Defense Switching Network	DSN	GEN
defense VFR	DVFR	GEN
definite	DFNT	GEN
degree	DEG	ICAO
delay or delayed	DLA	ICAO
delay account of	DLAC	ATC
delay clearance or delayed clearance	DLC	ATC
delay indefinite	DI	ATC
delay time	DLAT	ATC
delayed	RTD	ICAO
delete	DLT	GEN
deliver	DLVR	GEN
deliver by telephone	DELPHO	GEN
delivery	DLVY	GEN
demolition	DEMOL	GEN
demonstration	DMSTN	GEN
dense	DNS	NWS
dense upper cloud	DUC	ICAO
depart	DEP	ATC
department	DEPT	GEN
Department of Commerce	DOC	GEN
Department of Defense	DOD	GEN
Department of Energy	DOE	GEN
Department of Transportation	DOT	GEN
departure	DEP	ICAO
departure end of runway	DER	ICAO
departure approval request for IFR flight	DI	ATC
departure approved	DA	ATC
departure procedure	DPCR	ATC
Deployment Readiness Review	DRR	ATC
depth	DPT	ICAO
depth	DPTH	NWS
deputy chief	DCF	GEN
Deputy Commander for Operations	DO	GEN
descend	DSND	ATC
descend at pilot s discretion	DAPD	ATC
descend immediately	DSNDI	ATC
descend so as to cross	DSATX	ATC
descend so as to reach	DSATR	ATC
descend to and cross	DTAX	ATC
descend to and cruise	DCRZ	ATC
descend to and maintain	DTAM	ATC
descend to or descending to	DES	ICAO
descend well to right	DWTR	ATC
descend well to right of course	DWRC	ATC
descent	DSCNT	ATC
describe	DB	GEN
designate a friction value representing runway surface conditions (Greek letter)	MU	GEN
designated	DSGND	GEN
desire	DSR	GEN
destination	DESTN	GEN
destined	DSTND	ATC
detail	DTL	GEN
deteriorate	DTRT	NWS
determine	DTRM	GEN
develop	DVLP	GEN
deviation	DEV	ATC
deviation approved as requested	DAAR	ATC
dew point	DWPNT	NWS
dew point temperature	DP	ICAO
diagonal	DGNL	GEN
diameter	DIAM	GEN
difference in depth of modulation	DDM	GEN
differs	DFRS	GEN
difficult	DFCLT	GEN
diffuse	DFUS	GEN
diffuse	DIF	ICAO
digital altimeter setting indicator	DASI	GEN
Digital-Automatic Terminal Information Service	D-ATIS	ATC
digital barometer altimeter setting indicator	DBASI	GEN
Digital flight data recorder	DFDR	ICAO
diminish	DMSH	NWS
Diplomatic Telecommunications Service	DTS	GEN
direct	DCT	ICAO
direct	DRCT	GEN
direct altitude and identification readout equipment	DAIRE	GEN
Direct controller-pilot communications	DCPC	ICAO
direct current	DC	GEN
direct readout infrared	DRIR	GEN
direct route	DR	GEN
direct user access terminal system	DUATS	GEN
direction	DRCTN	GEN
Directives Management Officer, FAA	DMO	GEN
director	DIR	GEN
disabled	DISABLD	GEN
discontinue	DISC	GEN
dispersal	DSPRL	GEN
displace	DSPLC	GEN
Displaced runway threshold	DTHR	ICAO
display	DSPL	GEN
disposition	DSPN	GEN
disregard	DSRGD	GEN
disseminate	DISEM	GEN
dissipate	DSIPT	NWS
distance	DIST	ICAO
distance	DSTC	GEN
distance from touchdown indicator	DFTI	GEN
distance measuring equipment	DME	ICAO
Distance Root Mean Square	DRMS	ATC
distant	DSNT	GEN
distant early warning	DEW	GEN
distant early warning identification zone	DEWIZ	GEN
distinguished visitors	DV	GEN
distort	DST	GEN
Distress Phase Code (Alerting Service)	DETRESFA	ATC
distribute	DISTR	GEN
district	DIST	GEN
district airport engineer	DAE	GEN
ditto	DO	GEN
diverge	DVRG	GEN
diversion	DVRSN	GEN
divert	DIV	ICAO
division	DIV	GEN
DME-collocated with glide slope	DMEG	GEN
DME-collocated with localizer	DMEL	GEN
DME-collocated with VOR	DMEV	GEN
DME-tactical air navigation with DME only commissioned	DMER	GEN
do all possible	DAP	GEN
do not pass to Air Defense radar	NOPAR	ATC
Do you intend to ask me for a series of bearings? Or I intend to ask you for a series of bearings	QDL	ICAO
docking	DCKG	ICAO
document	DCMT	GEN
doing business as	DBA	GEN
domestic	DOM	ICAO
domestic services (island operations)	DS	GEN
dominant	DMNT	GEN
doppler VHF omni-directional radio range	DVOR	ICAO
double	DBL	GEN
double channel duplex	DCD	ICAO
double channel simplex	DCS	GEN
double sideband	DSB	ICAO
doubtful	DBTF	GEN
downdrafts	DWNDFTS	NWS
downslope	DNSLP	NWS
downstream	DNSTRM	NWS
downward vertical velocity	DVV	NWS
downwind	DNWND	ATC
drawing	DWG	GEN
drift	DRFT	NWS
drizzle	DRZL	NWS
drizzle	DZ	ICAO
dual tandem wheels	DTW	ICAO
dual wheels	DW	ICAO
duplex	DX	GEN
duplicate	DUPE	GEN
duration	DUR	ICAO
duration	DURN	GEN
during	DRG	ICAO
during	DURG	GEN
during climb	DURC	ATC
during descent	DURD	ATC
dust devils	PO	METAR
dust storm	DS	METAR
duststorm, sandstorm, rising dust or sand	SA	METAR

E

Definition	Contraction	Usage
each thousand foot level	ETFL	ATC
Early	ERY	GEN
early departure authorized	EDA	GEN
east or eastern longitude	E	ICAO
eastbound	EB	ICAO
eastbound	EBND	GEN
Eastern Region, FAA	AEA	GEN
Eastern Standard Time (time groups only)	E	NWS
eastern test range	ETR	ATC
east-north east	ENE	ICAO
east-northeastern (weather reports only)	ENERN	NWS
east-northeastward (weather reports only)	ENEWD	NWS
east-south east	ESE	ICAO
east-southeastern (weather reports only)	ESERN	NWS
east-southeastward (weather reports only)	ESEWD	NWS
effect	EFCT	GEN
effective	EFF	GEN
elapsed time	ETIM	ATC
electric	ELEC	GEN
electrical engineer	EENGR	GEN
electrician	ELECN	GEN
electronic counter measure mission	ECMSN	ATC
electronic counter measures	ECM	GEN
electronic equipment modification	EEM	GEN
electronic geographic coordinator navigation system	EGECON	GEN
electronic installation technician	EIT	GEN
electronic maintenance inspector	EMI	GEN
electronic maintenance technician	EMT	GEN
electronic mechanic technician	ELMT	GEN
electronic specialist	ECSP	GEN
electronic technician	ET	GEN
electronic unit	EU	GEN
electronic voice switching system	EVS	GEN
elevate or elevation	ELEV	ICAO
elliptical	ELIP	GEN
elongate	ELNGT	NWS
elsewhere	ELSW	GEN
embedded	EMBDD	NWS
embedded (in cloud layer)	EMBD	ICAO
emergency	EMERG	ICAO
emergency gear	EG	GEN
emergency location beacon - aircraft	ELBA	ICAO
emergency locator transmitter	ELT	GEN
emergency security control of air traffic	ESCAT	GEN
emergency use only	EUO	GEN
emission	EM	ICAO
en route	ENRT	GEN
en route automated radar tracking system	EARTS	GEN
en route communications	ECOM	GEN
en route communications	RCOM	GEN
en route metering	ERMG	ATC
en route penetration	EP	ATC
en route radar (broadband)	ERAD	GEN
en route secondary radar beacon (broadband)	ESEC	GEN
en route sequencing program	ESP	ATC
en route spacing program	ERSP	ATC
en route surveillance radar	RSR	ICAO
en route tracking automatic radar service	ETARS	ATC
encounter	ENCTR	GEN
encrypt for transmission only	EFTO	GEN
end exercise point	EEP	GEN
ending	ENDG	GEN
ending of precipitation (time in minutes) (weather reports only)	E	NWS
endurance	ENDCE	GEN
engine	ENG	ICAO
engineer	ENGR	GEN
Engineering and Manufacturing District Office	EMDO	GEN
engine-generator	E/G	GEN
enhanced	ENHNCD	GEN
enhancement	ENHNCMNT	GEN
en-route	ENR	ICAO
En-route chart (followed by name/title)	ENRC	ICAO
enter control area	ECA	ATC
enter controlled airspace	ECAS	ATC
entered on duty	EOD	GEN
entering air defense identification zone	EADIZ	ATC
entire	ENTR	GEN
entire field available	EFA	GEN
environment meteorological support unit	EMSU	NWS
equatorial (air mass)	E	NWS
equipment	EQPT	ICAO
equipment	EQUIP	GEN
equipment certified	EQCRT	GEN
equivalent airspeed	EAS	ATC
Error (to be used in AFS as a procedure signal)	EEE	ICAO
especially	SPCLY	GEN
essential	ESNTL	GEN
establish	ESTAB	GEN
estimate or estimation	EST	ICAO
estimated departure clearance (time)	EDCT	ATC
estimated elapsed time	EET	ICAO
estimated information	ETI	ATC
estimated latitude	ELAT	GEN
estimated longitude	ELONG	GEN
estimated off-block time	EOBT	ICAO
estimated time en route	ETE	GEN
estimated time of arrival	ETA	GEN
estimated time of departure	ETD	GEN
estimated time of penetration	ETP	ATC
estimated time over	ETOV	ATC
estimated time over significant point	ETO	ICAO
et cetera	ETC	GEN
Europe, Africa, and Middle East Office, FAA	AEU	GEN
Evacuation	EVAC	GEN
evaluate or evaluation	EVAL	GEN
Evening	EVE	GEN
Every	EV	ICAO
examination	EXAM	GEN
Except	EXC	ICAO
Except	EXCP	GEN
Except	XCP	NWS
except change departure to read	ECD	ATC
except change route to read	ECR	ATC
Exchange	EXCH	GEN
exchange and repair	E/R	GEN
Exclude	EXCLD	GEN
Exclusive	EXCLV	GEN
Execute	EXCT	GEN
Executive	EXEC	GEN
Exercise	EXER	ICAO
expanded position indicator	EPI	ATC
expanded quota flow	EXQF	ATC
expanded service volume	ESV	GEN
Expect	EXP	ICAO
Expect	EXPC	GEN
Expect	XPC	NWS
expect approach clearance	EACLN	ATC
expect approach clearance not later than	EACNL	ATC
expect departure clearance at	EDC	ATC
expect departure release at	EDR	ATC
expect further clearance at	EFC	ATC
expect further routing	EFR	ATC
expect higher altitude	EHA	ATC
expect vector to	EVT	ATC
expected approach time	EAT	ATC
expected operations forecast	EOF	NWS
expedite	EXPED	GEN
expedite delivery	EXDLVY	GEN
expedite delivery by telephone	EXPHO	GEN
expedite mail reply	EXREP	GEN
expedite shipment	EXSHI	GEN
explosive	XPLOS	GEN
express	EXPS	GEN
extend	EXTD	GEN
extension	EXTN	GEN
extensive	EXTSV	GEN
extra long range	ELR	ICAO
extra section	EXSEC	GEN
extrapolate	EXTRAP	NWS
extreme	EXTRM	NWS
extremely high frequency (30000 to 300000 MHz)	EHF	ICAO

F

Definition	Contraction	Usage
FAA Contract Flight Service Station	FCFSS	GEN
FAA Contract Weather Observing Station	FCWOS	GEN
FAA requirements	FAAR	GEN
facilitation of international air transport	FAL	ICAO
facilities	FAC	ICAO
facility	FAC	GEN
facility chief	FACF	GEN
facility coordination officer	FCO	GEN
facsimile	FAX	GEN
fahrenheit	F	GEN
fahrenheit	FAH	NWS
falling	FLG	NWS
familiar or familiarization	FAM	GEN
familiarization flight	FFLT	GEN
fan marker	FM	GEN
fan marker approach	FMAP	ATC
fan marker located with radio beacon	FMH	GEN
farther or further	FTHR	GEN
Fault Detection and Isolation	FDI	ATC
feathered	FTHRD	ATC
federal aid to airports program	FAAP	GEN
Federal Aviation Administration	FAA	GEN
Federal Aviation Regulations	FAR	GEN
Federal Communications Commission	FCC	GEN
Federal Telecommunications System	FTS	GEN
feet	FT	ICAO
feet per minute	FPM	GEN
field	FLD	ICAO
field condition	FICON	GEN
field condition report	FCRP	ATC
figure	FIG	GEN
filament	FIL	GEN
filed but impracticable to transmit	FIBI	NWS
filed flight plan	FPL	ICAO
filed flight plan in the air	AFIL	GEN
filed IFR flight plan	FIFP	ATC
filed VFR flight plan	FVFP	ATC
filing time	FT	GEN
filling	FILG	NWS
final approach	FA	ATC
final approach	FNA	ICAO
final approach fix	FAF	ICAO
final approach point	FAP	ICAO
fire warning	FWRNG	GEN
firing	FIRG	GEN
firing	FRNG	ICAO
first	FST	ICAO
first available	FIRAV	GEN
fixed federal monitoring network	FFMN	GEN
fixed pulse radar navigation aid	FPN	GEN
fixed wing special IFR	FW/SIFR	GEN
fixed wing special VFR	FW/SVFR	GEN
fixed-base operator	FBO	GEN
fix-radial-distance	FRD	ATC
flares	FLR	ICAO
flash advisory	FL	NWS
flashing	FLG	ICAO
Fleet Area Controlled and Surveillance Facility	FACSFAC	ATC
Fleet Weather Central	FWC	NWS
flight	FLT	ICAO
flight check	FLTCK	ICAO
flight data	FDAT	GEN
Flight Data Center	FDC	GEN
flight data entry and printout	FDEP	ATC
flight data input/output	FDIO	ATC
flight data input/output repeater	FDIOR	ATC
flight data position	FLIDAP	GEN
Flight data processing system	FDPS	ICAO
flight engineer	FE	GEN
flight information (permanent)	FI/P	GEN
flight information (temporary)	FI/T	GEN
Flight Information Center	FIC	GEN
flight information publication	FLIP	GEN
Flight Information Region	FIR	GEN
Flight Information Region Boundary	FIRB	GEN
flight information service	FIS	GEN
flight inspection	F	GEN
Flight Inspection District Office	FIDO	GEN
Flight Inspection Field Office	FIFO	GEN
Flight Inspection Field Office - High Altitude	FIFO-H	GEN
flight inspection group	FIG	GEN
flight level	FL	GEN
Flight management system	FMS	ICAO
flight orders	FLTO	GEN
flight path deviation indicator	FPDI	GEN
flight plan	FP	GEN
flight plan	PLN	ICAO
flight plan area	FPA	ATC
flight plan not received	FPNO	GEN
flight plan route	FPR	GEN
flight progress board	FPB	ATC
flight schedule monitor	FSM	ATC
Flight Service Station	FSS	ICAO
Flight Standards District Office	FSDO	GEN
Flight Standards National Field Office	FSNFO	GEN
flight strip printer	FSP	GEN
flight watch area	FWA	GEN
flight watch control station	FWCS	GEN
flight watch outlet	FLTWO	GEN
flight watch point	FWP	GEN
flight watch specialist	FWS	GEN
flight watch unit	FWU	GEN
flood stage	FLDST	NWS
flood warning issued	FLWIS	NWS
florescan instrument landing system	FILS	GEN
flow control time of arrival	FCTA	ATC
flow management unit	FMU	ICAO
fluctuating	FLUC	ICAO
fluctuation	FLCTN	GEN
fluorescent runway lighting (floodlight system)	FLORL	GEN
flurry	FLRY	NWS
fly runway heading	FRH	ATC
fog	FG	METAR
fog dispersal operations	DENEB	ICAO
fog in vicinity	VCFG	METAR
fog partial	PRFG	METAR
fog patches	BCFG	NWS
follow	FLW	GEN
following amendment authorized effective	FAMAE	GEN
following transmitted as received (message handling)	FTAR	GEN
foot	FT	GEN
for an approach to	FAA	ATC
for further clearance	FFC	ATC
for possible reclearance	FPRC	ATC
for your information	FYI	GEN
forecast upper wind and temperature for aviation	WINTEM	ICAO
forecast	FCST	GEN
forecast upper wind and temperature at specified points	ARMET	GEN
forecast wind factor	FRWF	NWS
foreign object debris	FOD	GEN
forenoon	FORNN	NWS
form	FRM	GEN
format	FMT	GEN
formation	FRMN	GEN
forming	FRMG	NWS
forward	FWD	GEN
forward collect	FWDC	GEN
forward visibility (miles)	FV	ATC
forward visibility more than (miles)	MFV	ATC
freeze	FRZ	NWS
freezing drizzle	FZDZ	METAR
freezing fog	FZFG	METAR
freezing level	FRZLVL	NWS
freezing rain	FZRA	METAR
freezing rain information not available (weather reports only)	ZRNO	NWS
freezing rain sensor not available	FZRANO	METAR
frequency	FREQ	ICAO
frequency change approved	FCA	ATC
frequency division data link	FDDL	GEN
frequency management officer	FMO	GEN
frequent	FQT	GEN
frequent	FRQ	ICAO
Friday	FRI	ICAO
from	FM	ICAO
From (used to precede the call sign of the calling station)	DE	ICAO
from present position	FPP	ATC
front	FNT	NWS
frontal passage	FROPA	NWS
frontal surface	FROSFC	NWS
frontogenesis	FNTGNS	NWS
frontolysis	FNTLYS	NWS
frost	FRST	NWS
frozen	FRZN	NWS
FSS assumes control of tower frequencies and lights	FATFL	GEN
FSS assumes flight-plan area and Service B	FAFAB	GEN
FSS guarding Service B	FGSB	GEN
FSS returns control of tower frequencies and lights	FRTFL	GEN
FSS returns flight-plan area and Service B	FRFAB	GEN
FSS returns Service B	FRSB	GEN
fuel advisory	FA	ATC
fuel advisory departure	FAD	GEN
fuel on board	FOB	GEN
fuel remaining	FR	GEN
fuel supply exhausted	FEXHA	ATC
fuel supply unknown	FENKN	ATC
fuel supply until	FENTL	ATC
full performance level	FPL	ATC
full route clearance	FRC	GEN
full stop landing	FSL	ICAO
function	FNCTN	GEN
funnel cloud	FC	METAR
furnish	FURN	GEN
further particulars when available	FPWA	ATC

G

Definition	Contraction	Usage
gain time control	GTC	ATC
gallons	GALS	ATC
garble	GRBL	GEN
GBAS Landing System	GLS	ICAO
general	GEN	GEN
general aviation	GA	ICAO
General Aviation District Office	GADO	GEN
general notice	GENOT	GEN
General Safety District Office	GSDO	GEN
general safety inspector	GSI	GEN
General Services Administration	GSA	GEN
generator	GNTR	GEN
geographic	GEO	GEN
geographical reference	GEOREF	GEN
Geoid undulation	GUND	ICAO
get quick answer	GQA	GEN
gigahertz	GHZ	GEN
give better address	GBA	GEN
give better reference	GBR	GEN
giving	GVG	GEN
glaze icing	GICG	NWS
glide angle	GA	GEN
glide path	GP	ICAO
glide path angle	GPA	ICAO
glide slope	GS	GEN
glider	GLD	ICAO
glider	GLDR	GEN
global navigation satellite system	GLONASS	ICAO
global navigation satellite system (in general)	GNSS	ICAO
Global orbiting navigation satellite system	GLONASS	ICAO
global positioning system	GPS	ICAO
Go ahead, resume sending (to be used in AFS as a procedure signal)	GA	ICAO
government	GOVT	GEN
government bill of lading	GBL	GEN
government vehicle	GVH	GEN
Governor	GOV	GEN
GPS Integrity Channel	GIC	ATC
gradient	GRAD	NWS
gradual	GRADU	ICAO
gradual	GRDL	NWS
Grand Banks	GRBNKS	NWS
grass landing area	GRASS	ICAO
gravel	GRVL	ICAO
Great Circle	GTCL	GEN
Great Lakes	GRTLKS	NWS
Great Lakes Region, FAA	AGL	GEN
greater	GTR	GEN
green	G	ICAO
Greenwich Mean Time	GMT	GEN
Greenwich Mean Time	Z	GEN
grid point values of processed meteorological data	GRID	ICAO
gross weight	GWT	GEN
ground	GND	ICAO
ground-based augmentation system	GBAS	ICAO
ground check	GNDCK	ICAO
ground communication outlet	GCO	ATC
ground control	GC	GEN
ground control approach	GCA	ICAO
ground control intercept	GCI	GEN
ground delay program	GDPGM	ATC
ground delay program	GDP	ATC
ground earth station	GES	ICAO
ground fog	GNDFG	NWS
ground movement chart (followed by name/title)	GMC	ICAO
ground point of intercept	GPI	ATC
ground speed	GS	ATC
ground stop	GS	ATC
ground to air	G/A	ICAO
ground to air and air to ground	G/A/G	ICAO
ground visibility	GV	NWS
Gulf of Alaska	GLFALSK	NWS
Gulf of California	GLFCAL	NWS
Gulf of Mexico	GLFMEX	NWS
Gulf of St. Lawrence	GLFSTLAWR	NWS
gusts	GSTS	NWS
gusts reaching (knots) (weather reports only)	G	NWS
gusty	GSTY	NWS

H

Definition	Contraction	Usage
hail (greater than 3/4 )	GR	METAR
hail showers	SHGR	METAR
hail showers (small)	SHGS	METAR
hailstones	HLSTO	NWS
half	HLF	GEN
handoff point	HOP	ATC
handover word	HOW	ATC
hangar	HNGR	GEN
hard freeze	HDFRZ	NWS
Hawaiian Air Defense Division	HADD	GEN
Hawaiian Air Defense Identification Zone	HADIZ	GEN
Hawaiian Air National Guard	HANG	GEN
Hawaiian Defense Area	HADA	GEN
hazard	HAZ	GEN
hazard beacon	HBN	ICAO
hazardous area reporting service	HARS	ATC
hazardous inflight weather advisory service	HIWAS	GEN
hazardous material	HAZMAT	ICAO
haze	HZ	METAR
Head of State status	HEAD	ICAO
heading	HDG	ICAO
headquarters	HQ	GEN
headwind	HDWND	ATC
heater	HTR	GEN
heavy	HVY	ICAO
heavy (to qualify weather phenomena, e.g. XXRA - heavy rain)	XX	ICAO
hectopascal	HPA	ICAO
height	HGT	ICAO
height above airport	HAA	GEN
height above landing	HAL	GEN
height above touchdown	HAT	GEN
helicopter	HEL	ICAO
helicopter operations	HOP	GEN
heliport	HELI	GEN
heliport	HLP	ICAO
here	ER	ICAO
here	HR	GEN
hertz	Hz	GEN
heterodyne	HTN	GEN
high	HI	NWS
high altitude balloon	HIBAL	GEN
high and very high frequency direction finding stations	HVDF	ICAO
high clouds visible	HCVIS	NWS
high density traffic airport	HDTA	GEN
high density traffic zones	HDATZ	ATC
high frequency	HF	GEN
high frequency direction finding station	HDF	ICAO
high index	HX	NWS
high intensity approach light system	HIALS	GEN
high intensity runway lights	HIRL	GEN
high level forecast	HIFOR	NWS
high voltage	HV	GEN
higher	HYR	ICAO
highest temperature	HITMP	NWS
highest temperature equaled for all time	HIEAT	NWS
highest temperature equaled for the month	HIEFM	NWS
highest temperature equaled so early	HIESE	NWS
highest temperature equaled so late	HIESL	NWS
highest temperature exceeded for all time	HIXAT	NWS
highest temperature exceeded for the month	HIXFM	NWS
highest temperature exceeded so early	HIXSE	NWS
highest temperature exceeded so late	HIXSL	NWS
highway	HWY	GEN
hilltop	HLTP	NWS
hold for release	HFR	ATC
holding	HLDG	ICAO
holding as previously instructed	HAPI	ATC
holding pattern	HP	GEN
holiday	HOL	GEN
homing beacon	HB	ATC
horizon	HRZN	GEN
Horizontal Dilution of Precision	HDOP	ATC
hospital aircraft	HOSP	ICAO
hour	HR	ICAO
household effects	HHE	GEN
how will arrival report be filed concerning	HIRIV	ATC
however	HWVR	GEN
Hudson Valley	HDSVLY	NWS
humanitarian mission	HUM	ICAO
hundred	HND	GEN
hurricane	HURCN	ICAO
hurricane report	HUREP	NWS
hydraulic	HYD	GEN
hydrographic	HYDRO	GEN

I

Definition	Contraction	Usage
ICAO Middle East/Asia Region	MID/ASIA	ATC
ice crystals (weather reports only)	IC	METAR
ice on runway	IR	NWS
ice pellet showers	SHPL	METAR
ice pellets	PL	METAR
icing	ICG	NWS
icing (PIREP only)	IC	ATC
icing in clouds	ICGIC	NWS
icing in clouds and precipitation	ICGICIP	NWS
icing in precipitation	ICGIP	NWS
identify or identifier	ID	ICAO
identification beacon	IBN	ICAO
identification friend/foe	IFF	ICAO
identification	IDENT	ICAO
if approach missed proceed	IFAMP	ATC
if authorized by ATC, DME may be used	IAATCD	ATC
if flight visibility becomes less than	IFVLS	ATC
if holding	IFHOL	ATC
if incorrect advise	IIA	GEN
if incorrect service direct	IISD	GEN
if instrument conditions encountered	IFINS	ATC
if not off	INOF	GEN
if not possible	INP	GEN
if unable	IFUN	GEN
if visibility remains	IFVR	ATC
IFR military training route	IR	GEN
ILS-partial	ILSP	GEN
immediate	IMDT	NWS
immediate or immediately	IMT	GEN
immediately after passing	IMAP	ATC
immigration	IMG	ICAO
important	IMPT	GEN
impracticable	IMP	GEN
improve	IMPR	ICAO
improve	IPV	GEN
impulse	IMPL	GEN
in accordance with	IAW	GEN
in and out of clouds	IAO	ICAO
in clouds	INC	ICAO
in overcast	IOVC	NWS
in progress	INPR	ICAO
in RVR indicates visibility greater than highest reportable sensor value (e.g. P600FT)	P	METAR
in RVR indicates visibility less than lowest reportable sensor value (e.g. M600)	M	METAR
in temperature field means minus or below zero	M	METAR
in the vicinity of	INVOF	ATC
in valleys	VAL	ICAO
in VFR conditions	IVFRC	ATC
inadequate	INADQT	GEN
inbound	IBND	ATC
inbound	INBD	ICAO
inbound radial	IRAD	ATC
inch	IN	ICAO
include	INCL	GEN
inclusive	INCLV	GEN
incomplete	INCOMP	GEN
incorporated	INC	GEN
incorrect	INCOR	GEN
increase	INCR	GEN
indefinite	INDEF	GEN
independent sideband	ISB	ICAO
indicate	INDC	GEN
indicated air speed	IAS	ATC
Indication of a request	RQ	ICAO
individual development plan	IDP	GEN
individual flight plans from this point	IFPFP	ATC
industrial	INDUS	GEN
inertial navigation system	INS	ICAO
information	INFO	ICAO
information request	INREQ	GEN
initial approach	INA	ICAO
initial approach fix	IAF	ICAO
initial point	IP	ATC
initial point/H-hour control line	IP/HHCL	ATC
initial training	INIT	GEN
inland	INLD	NWS
inland	LAN	ICAO
inland navigation facility	INF	GEN
inner marker	IM	ICAO
inoperative	INOP	ICAO
inspect	INSP	GEN
instability	INSTBY	NWS
install	INSTL	GEN
instruct	INSTR	GEN
instructor pilot	IP	GEN
instrument	INST	GEN
instrument	INSTR	ICAO
instrument approach chart (followed by name/title)	IAC	ICAO
instrument approach procedure	IAP	ICAO
instrument flight rules	IFR	ICAO
instrument landing system	ILS	ICAO
instrument low approach	ILAS	ATC
instrument meteorological conditions	IMC	GEN
instruments authorized	INSTA	ATC
insufficient scheduled time available	INSUF	GEN
intend	INTD	GEN
intense	INTS	NWS
intensify	INTSFY	NWS
intensify or intensifying	INTSF	ICAO
intensity	INTST	ICAO
Intensity unknown (weather reports only)	IMI	ICAO
intensity unknown (weather reports only)	U	NWS
intentions	INTNS	GEN
Interagency Group on International Aviation	IGIA	GEN
intercept	INTCP	GEN
intercontinental	INTCNTL	GEN
Interdepartmental Radio Advisory Committee	IRAC	GEN
Interface Control Document	ICD	ATC
Interface Revision Notices	IRN	ATC
interfacility data	IDAT	GEN
interference	INTFC	GEN
interim standard microwave landing system	ISMLS	GEN
interior	INTR	NWS
intermediate	INTMD	GEN
intermediate approach fix	IF	ICAO
intermediate fix	IF	GEN
intermittent	INTER	ICAO
intermittent	INTMT	GEN
intermittent instruments	I/IFR	ATC
Inter-Mountain Region	INTRMTRGN	NWS
international	INTL	ICAO
International Administrative Aeronautical Radio Conference	IAARC	GEN
International Aeronautical Telecommunications Switching Center	IATSC	GEN
International Air Transport Association	IATA	GEN
International Civil Aviation Organization	ICAO	GEN
international dateline	DTLN	NWS
International Field Office	IFO	GEN
International Flight Information Manual	IFIM	GEN
International Flight Service Station	IFSS	GEN
international general aviation	IGA	ICAO
international standard atmosphere	ISA	ICAO
International Telecommunications Union	ITU	GEN
interphone	IFO	GEN
interphone (service F) not operative	IFONO	GEN
interphone (service F) resumed operation	IFORO	GEN
interrogation sign	IMF	GEN
interrogator	INTRG	ICAO
interrupt	INTRP	GEN
interruption of air traffic services	INATS	GEN
intersection	INT	ICAO
intersection	INTXN	GEN
intersection of air routes	IAR	ICAO
interstate	INSTA	GEN
interval	INTVL	GEN
intervals between aircraft in stream type formation	IBASF	ATC
inversion	INVRN	NWS
investigate	INVES	GEN
investigate and report	INVSTAR	GEN
irregular	IREG	GEN
island	IS	GEN
Island Manager	ISMGR	GEN
isolate	ISOL	GEN
issue time check	ITCK	ATC
itinerant	ITNRNT	GEN
itinerary	ITRY	GEN

J

Definition	Contraction	Usage
jet approach landing charts	JAL	GEN
jet assisted take-off	JATO	ATC
jet penetration	JP	ATC
jet penetration approach	JPAP	ATC
jet runway barrier	J-BAR	ATC
jet stream	JTST	ICAO
jet stream	JTSTR	NWS
jet terminal area	Z	ATC
join airways	JAWYS	ATC
journeyman	JOUR	GEN
junction	JCTN	GEN

K

Definition	Contraction	Usage
keep this office advised	KEPOA	GEN
killing frost	KFRST	NWS
kilocycles	KC	GEN
kilogram	KG	GEN
kilohertz	KHZ	GEN
kilometers	KM	GEN
kilometers per hour	KMH	ICAO
kilopascal	KPA	ICAO
kilowatt	KW	GEN
knots	KT	GEN

L

Definition	Contraction	Usage
Laboratory	LAB	GEN
labrador	LABRDR	NWS
lake	LK	NWS
lake reporting service	LRS	GEN
laminar flow control	LFC	GEN
land	LND	GEN
land lines communications facilities	LICOF	GEN
landing	LDG	ICAO
landing	LNDG	GEN
landing direction indicator	LDI	ICAO
landing distance available	LDA	ICAO
landing rights airport	LRA	GEN
landing traffic	LTFC	ATC
landline	LL	GEN
landline teletypewriter	LTT	ICAO
large	LRG	GEN
last radio contact	LARCT	ATC
later	LTR	GEN
lateral navigation (from TERPS-A1)	LNAV	GEN
latitude	LAT	ICAO
latter	LTTR	GEN
layer or layered or layers	LYR	NWS
lead in lighting system	LDIN	GEN
leased Service A/B system	LABS	ATC
leave or leaving	LVE	ICAO
leaving	LV	GEN
leaving	LVG	ATC
left	L	ICAO
left base	LB	ATC
left side	LS	ATC
left traffic pattern	LP	ATC
length	LEN	ICAO
letter	LTR	GEN
letter follows	LETFO	GEN
letter of agreement	LOA	GEN
level	LVL	ATC
level off	LVLOF	ATC
liaison officer	LO	GEN
lift	LFT	NWS
light or lighting	LGT	ICAO
light and variable	LTAV	GEN
light and variable	LV	ICAO
light intensity high	LIH	ICAO
light intensity low	LIL	ICAO
light intensity medium	LIM	ICAO
lighted	LGTD	ICAO
lightning	LTNG	NWS
lightning cloud-to-air	LTGCA	NWS
lightning cloud-to-cloud	LTGCC	NWS
lightning cloud-to-cloud, cloud to ground	LTGCCCG	NWS
lightning cloud-to-ground	LTGCG	NWS
lightning cloud-to-water	LTGCW	NWS
lightning in clouds	LTGIC	NWS
like type	LKTYP	ATC
likely	LKLY	GEN
limit	LMT	GEN
limited	LTD	ICAO
Limited Aviation Weather Reporting Station	LAWRS	GEN
line	LN	GEN
line of position	LOP	GEN
line squall	LSQ	ICAO
linear polarization	LP	ATC
linearity	LIN	GEN
liquid propane	LP	GEN
little	LTL	GEN
little change	LTLCG	NWS
little change in temperature	LCTMP	NWS
local airport advisory	LAA	GEN
local airport deicing plan	LADP	ATC
Local Area Augmentation System	LAAS	ATC
local control	LC	GEN
local coordinator	LOCOR	GEN
Local Mean Time	LMT	ICAO
local or locally	LCL	GEN
local standard time	LST	GEN
local training flight	LTF	ATC
localizer	LOC	ICAO
localizer (not associated with ILS)	LLZ	ICAO
Localizer performance without vertical guidance	LP	GEN
Localizer performance with vertical guidance	LPV	ICAO
localizer type directional aid	LDA	ATC
locally	LCA	ICAO
locate	LCT	GEN
location (PIREP only)	OV	ATC
locator	L	ICAO
locator middle	LM	ICAO
logical acknowledgement	LAM	ICAO
logistics	L	GEN
long distance	LD	GEN
long distance navigation	LODISNAV	GEN
long range	LGRNG	NWS
long range	LRG	GEN
long range accuracy	LORAC	GEN
long range air navigation system	LORAN	GEN
long range VHF/UHF communications	LRCOM	GEN
long wave	LGWV	GEN
longitude	LONG	ICAO
longitudinal	LONGL	GEN
loose snow on runway	LSR	NWS
low altitude arrival/departure routing	LAADR	ATC
low altitude bombing system	LABS	GEN
low approach	LA	ATC
low drifting	DR	METAR
low drifting dust	DRDU	METAR
low drifting sand	DRSA	METAR
low drifting snow	DRSN	METAR
low frequency	LF	GEN
low frequency intersection	LFNT	GEN
low frequency radio range	LFR	GEN
low IFR (weather reports only)	LIFR	NWS
low index	LX	NWS
low intensity runway edge lights	LIRL	GEN
low level wind shear	LLWS	GEN
low level wind shear alert system	LLWAS	GEN
low or medium frequency long range navigational aid	CONSOLAN	GEN
low or medium frequency radio range stations	RR	GEN
low/medium frequency	L/MF	GEN
low visibility operations	LVO	GEN
lower	LWR	GEN
lowest temperature	LOTMP	NWS
lowest temperature equaled for all time	LOEAT	NWS
lowest temperature equaled for the month	LOEFM	NWS
lowest temperature equaled so early	LOESE	NWS
lowest temperature equaled so late	LOESL	NWS
lowest temperature exceeded for all time	LOXAT	NWS
lowest temperature exceeded for the month	LOXFM	NWS
lowest temperature exceeded so early	LOXSE	NWS
lowest temperature exceeded so late	LOXSL	NWS

M

Definition	Contraction	Usage
Mach number	M	GEN
MACH Number (speed ratio to speed of sound)	MACH	ATC
Mackay Radio and Telegraph Company	MACKAY	GEN
magnetic	MAG	GEN
magnetic bearing	QDR	ICAO
magnetic heading	MHDG	GEN
magnetic heading	QDM	ICAO
magnetic orientation of runway	QFU	ICAO
magnetic variation	VAR	ICAO
main meteorological office	MMO	NWS
mainland	MNLD	NWS
mainly	MNLY	GEN
maintain	MNTN	ICAO
maintain a position VFR and advise	MPVA	ATC
maintain at least (altitude)	MAL	ATC
maintain flight level	MFL	ATC
maintain Mach	MMACH	ATC
maintain VFR	MVFR	ATC
maintain visual separation	MVSP	ATC
maintain well to right of course	MWRC	ATC
maintaining visual flight (Special VFR)	VF	ATC
maintenance	MAINT	ICAO
maintenance assumes monitor	MAM	GEN
maintenance check	MCK	GEN
maintenance returns monitor	MRM	GEN
make altitude changes VFR	MACVFR	ATC
make check turn	MKCT	ATC
make descent from	MDFR	ATC
make good a magnetic track of (degrees)	MGMT	ATC
make good a track of (degrees)	MGAT	ATC
management	MGMT	GEN
manager	MGR	GEN
maneuver	MNVR	GEN
Manitoba	MAN	NWS
manual	MAN	GEN
manual A1 simplex	MAS	ICAO
manual amendment	MANAM	GEN
manual of operations	MANOP	GEN
manufacturing inspector	MI	GEN
map analysis	MA	NWS
marginal	MRGL	NWS
marginal VFR	MVFR	NWS
Marine Corps Air Station	MCAS	GEN
Marine Corps Air Station (Helicopter)	MCAS(H)	GEN
maritime	MRTM	NWS
maritime (air mass)	M	NWS
marked	MKD	GEN
marker	MKR	GEN
marker beacon	MB	GEN
marker radio beacon	MKR	ICAO
marking	MRKG	GEN
Master Control Station	MCS	ATC
master flight plan on file	MFPOF	ATC
material	MTRL	GEN
maximum	MAX	GEN
maximum authorized (IFR) altitude	MAA	GEN
maximum usable altitude	MUA	GEN
maximum usable frequency	MUF	GEN
meaconing, intrusion, jamming, interference	MIJI	ATC
mean sea level	MSL	ICAO
mechanic	MECH	GEN
mechanical reliability report	MRR	GEN
medical	MED	GEN
medical emergency evacuation	MEDEVAC	ICAO
medium	MED	GEN
medium and high frequency direction-finding station (same location)	MHDF	ICAO
medium and very high frequency direction-finding station (same location)	MVDF	ICAO
medium frequency	MF	GEN
medium frequency direction finding station	MDF	ICAO
medium high and very high frequency direction-finding station (same location)	MHVDF	ICAO
medium intensity approach lighting system	MALS	GEN
medium intensity approach lighting system with runway alignment indicator lights	MALSR	GEN
medium intensity approach lighting system with sequenced flashers	MALSF	GEN
medium intensity runway edge lights	MIRL	GEN
medium range	MRG	GEN
megahertz	MHZ	ICAO
melting level	MLTLVL	NWS
memorandum of agreement	MOA	GEN
memorial	MEML	GEN
merging	MEGG	NWS
Merit Promotion Program	MPP	GEN
message	MSG	ICAO
Message (transmission identification) has been misrouted	MSR	ICAO
message center	MSGCTR	GEN
meteorological	MET	GEN
Meteorological Aeronautical Presentation System	MAPS	GEN
meteorological information for aircraft in flight	VOLMET	ICAO
meteorological officer	METOF	GEN
Meteorological Operational Telecommunications Network Europe	MOTNE	ICAO
Meteorological Watch Office	MWO	ICAO
meter fix time	MFXT	ATC
meters per second	MPS	ICAO
metres (preceded by figures)	M	ICAO
metric units	MTU	ICAO
metropolitan	METRO	GEN
Mexico	MEX	NWS
microburst	MBST	ICAO
microwave landing system	MLS	GEN
Mid-Canada Identification Zone	MIDIZ	GEN
middle	MID	GEN
middle marker	MM	ICAO
midnight	MIDN	NWS
midpoint	MIDPT	GEN
mid-point (related to RVR)	MID	ICAO
Mike Monroney Aeronautical Center, FAA	AAC	GEN
mile	MI	GEN
miles in trail	MIT	ATC
miles per hour	MPH	GEN
military	MIL	ICAO
Military Airlift Command	MAC	GEN
military alert system	MAS	GEN
military assumes responsibility for separation of aircraft	MARSA	GEN
military, customs, or police services	STATE	ICAO
military flight service	MFS	GEN
military height finder radar	MHFR	GEN
military operations area	MOA	ICAO
Military Radar Unit	MRU	GEN
military training route	MTR	GEN
millibars	MB	GEN
millimeter	MM	GEN
millivolt	MV	GEN
mimeographic notice	MIMNO	GEN
minimum	MNM	ICAO
minimum altitude at glide slope intersection inbound	MAGSI	GEN
minimum altitude over facility on final approach course	MAFAP	ATC
minimum crossing altitude	MCA	ICAO
minimum descent altitude	MDA	ICAO
minimum descent height	MDH	ICAO
minimum en route altitude	MEA	ICAO
minimum eye height over threshold	MEHT	ICAO
minimum fuel on board	MFOB	ATC
minimum holding altitude	MHA	GEN
minimum interval take-off	MITO	ATC
minimum navigation performance specification	MNPS	ATC
minimum navigation performance specification airspace	MNPSA	ATC
minimum obstacle clearance (required)	MOC	ICAO
minimum obstruction clearance altitude	MOCA	ICAO
Minimum operational performance standards	MOPS	ICAO
minimum reception altitude	MRA	GEN
minimum requirements specified	MIREQ	GEN
minimum safe altitude warning	MSAW	GEN
minimum safe/sector altitude	MSA	GEN
minimum terrain clearance altitude	MTCA	GEN
minimum vector altitude	MVA	GEN
minimum when control zone effective	MCZNE	GEN
Ministry of Transport (Canada)	MOT	GEN
minus	MS	NWS
minute	MIN	ICAO
minutes in trail	MINIT	ATC
miscellaneous	MISC	GEN
missed approach point	MAP	GEN
missed approach point	MAPT	ICAO
missile	MISL	GEN
missing	MISG	GEN
missing (weather reports only)	M	NWS
Missing (transmission identification)	MIS	ICAO
mist	BR	METAR
mixed	MXD	NWS
moderate	MDT	GEN
moderate	MOD	GEN
moderate or greater	MOGR	NWS
modernization	MDZN	GEN
modernize	MDZ	GEN
modernized weather teletypewriter communications system	MWTCS	GEN
modify	MDFY	GEN
modulate or modulation or modulator	MOD	GEN
modulated continuous wave	MCW	ICAO
Mohawk Valley	MHKVLY	NWS
moisture	MSTR	NWS
momentary	MTRY	GEN
Monday	MON	ICAO
monitor,monitored, or monitoring	MNT	ICAO
monitor	MONTR	NWS
monitor out of service	MONOS	GEN
monitor resumed normal operation	MONOK	GEN
monitor station reports	MOREPS	GEN
Monopulse secondary surveillance radar	MSSR	ICAO
morning	MRNG	NWS
mostly	MSTLY	NWS
mountain	MT	ICAO
mountain	MTN	NWS
Mountain Standard Time (time groups only)	M	NWS
mountain wave	MTW	ICAO
Move, or moving, or movement	MOV	ICAO
moving target indicator	MTI	ATC
multi-object phase tracking and ranging	MOPTAR	GEN
multiple	MULT	GEN
municipal	MUNI	GEN
municipal airport	MARPT	GEN
must ride company material	RIMAT	GEN

N

Definition	Contraction	Usage
name to	NTO	GEN
Narrow	NRW	GEN
National	NATL	GEN
National	NTL	ICAO
National Aeronautics and Space Administration	NASA	GEN
National Air Traffic Controllers Association	NATCA	ATC
National Air Transport Coordinating Committee	NATCC	GEN
National Aircraft Noise Abatement Council	NANAC	GEN
National Airport System Plan	NASP	GEN
National Airspace Data Interchange Network	NADIN	GEN
National Airspace Performance Reporting System	NAPRS	ATC
National Airspace System	NAS	GEN
National Airspace System Interfacility Communications System	NICS	GEN
National Airways System Engineering office	NASEO	GEN
National AIS system centre	NASC	ICAO
National Association of Air Traffic Control Specialists	NAATS	GEN
National Aviation Facilities Experimental Center	NAFEC	GEN
national beacon code allocation plan	NBCAP	GEN
National Climatic Data Center	NCDC	GEN
National Communications Center	NATCOM	GEN
national communications schedule	NACOS	GEN
National Communications System	NCS	GEN
national environmental satellite service	NESS	GEN
National Flight Data Digest	NFDD	GEN
National Guard	NG	GEN
National Meteorological Center	NMC	GEN
National Ocean Service	NOS	GEN
National Oceanic and Atmospheric Administration	NOAA	GEN
National Severe Storm Forecast Center	NSSFC	GEN
National Track Analysis Program	NTAP	ATC
National Transportation Safety Board	NTSB	GEN
National Weather Service	NWS	GEN
National Weather Service Support Facility	WSSF	GEN
National Weather Service Support Unit	WSSU	GEN
nautical mile	NM	CAO
nautical mile radius	NMR	GEN
Naval Air Facility	NAF	GEN
Naval Air Station	NAS	GEN
Naval Auxiliary Air Station	NAAS	GEN
Naval Oceanographic Meteorological Automatic Device	NOMAD	GEN
Naval Outlying Landing Field	NOLF	GEN
Naval Reserve Air Base	NRAB	GEN
Naval Weather Service Office	NWSO	GEN
navigation	NAV	ICAO
Navigation, ATC, and Collision Avoidance System	NATCAS	GEN
navigational aid	NAVAID	GEN
Navy Liaison Officer	NAVLO	GEN
Navy Representative to the FAA	NAVREP	GEN
NDB and DME (collocated)	NDB/DME	GEN
near	NR	GEN
near or over large towns	CIT	ICAO
necessary	NEC	GEN
negative	NEG	GEN
negative replies not required	NONEG	GEN
negative vorticity advection	NVA	NWS
neighborhood	NBRHD	GEN
New Brunswick	NB	NWS
New England	NEW ENG	NWS
New England Region, FAA	ANE	GEN
Newfoundland	NFLD	NWS
next	NXT	GEN
night	NGT	ICAO
night frequency	NFQ	GEN
nimbostratus	NS	NWS
No (negative)	NO	ICAO
no action necessary	NOAC	GEN
no additional traffic reported	NATR	ATC
no arrival report	NORIV	ATC
no change	NC	GEN
no change in estimates	NCE	ATC
no change in weather	NCWX	NWS
no delay expected	NDE	ATC
no essential traffic reported	NETR	ATC
no filing time	NFT	GEN
no further clearance required	NEF	ATC
no further information	NOFIN	GEN
no information	NOIFN	GEN
no layers	NL	NWS
no middle name	NMN	GEN
no parallel traffic	NPRL	ATC
no pilot balloon observation due to high, or gusty, surface wind	PIWI	NWS
no pilot balloon observation due to snow	PISO	NWS
no pilot balloon observation due to unfavorable sea conditions	PISE	NWS
no pilot balloon observation will be filed next collection unless weather changes significantly	NORPI	NWS
no procedure turn required	NOPT	GEN
no radio	NORDO	GEN
no radio contact	NORAC	ATC
no RAWIN obs., communications out	RACO	NWS
no RAWIN obs., high and gusty winds	RAWI	NWS
no RAWIN obs., no balloons available	RABA	NWS
no RAWIN obs., no gas available	RAHE	NWS
no RAWIN obs., unfavorable weather	RAWE	NWS
no record	NOREC	GEN
no record of destination	NRD	GEN
no reply heard	NRH	ICAO
no reply received	NORR	GEN
no report	NOREP	GEN
no restrictions	NORST	GEN
no significant change	NOSIG	ICAO
no significant cloud	NSC	ICAO
no significant weather	NSW	METAR
no small craft or storm warning are being displayed	NSCSWD	NWS
no special observations taken (weather reports only)	NOSPL	NWS
no specific working hours	HX	ICAO
no traffic reported	NTRP	ATC
no transgression zone	NTZ	ATC
No transgression zone	NTZ	ICAO
no trouble found	NTFND	GEN
noise abatement test system	NATS	GEN
nondirectional radio beacon	NDB	ICAO
none	NIL	GEN
nonpersistent	NPRS	NWS
nonprecision instrument	NPI	GEN
nonrevenue	NRV	GEN
non-RVSM capable flight	NONRVSM	ICAO
Nonstandard C/A Code	NSC	ATC
nonstandard holding pattern	NSP	GEN
nonstop	NSTP	GEN
NORAD Region Operations Control Center	ROCC	GEN
NORAD Sector Operations Control Center	SOCC	GEN
normal	NML	GEN
normal operating zone	NOZ	GEN
Normal operating zone	NOZ	ICAO
North American Aerospace Defense Command	NORAD	GEN
North American Route	NAR	GEN
North American route program	NRP	ATC
North Atlantic	NAT	GEN
north or northern latitude	N	ICAO
North Pacific	NOPAC	ATC
northbound	NB	ICAO
northbound	NBND	GEN
north-east	NE	ICAO
north-eastbound	NEB	ICAO
northeasterly (weather reports only)	NELY	NWS
northeastern	NERN	NWS
north-north east	NNE	ICAO
north-north west	NNW	ICAO
north-northeastern (weather reports only)	NNERN	NWS
north-northeastward (weather reports only)	NNEWD	NWS
north-northwestern (weather reports only)	NNWRN	NWS
north-west	NW	ICAO
Northwest Mountain Region, FAA	ANM	GEN
north-westbound	NWB	ICAO
northwesterly (weather reports only)	NWLY	NWS
northwestern (weather reports only)	NWRN	NWS
north-westward (weather reports only)	NNWWD	NWS
not above	NAB	GEN
not according to routine	NAR	GEN
not applicable	N/A	GEN
not ARTS tracked	NAT	ATC
not at present	NAP	GEN
not authorized	NA	GEN
not available	NO	METAR
not before	NBFR	ICAO