Terminology & Decoding

Go To | Weather | NOTAM | Definitions | Abbreviations |

This page provides a comprehensive guide on decoding weather information, and terminology that is used in Aviation. Which is essential for pilots crewed and uncrewed and aviation professionals that inform them about changes or hazards that may affect flight operations. It covers:

NOTAM Decoding:
- This section includes links to automated NOTAM decoders, as well as an example of how to decode a NOTAM and a full list of acronyms that are used in NOTAMS which is available for download as a PDF.
Aviation Abbreviations and Definitions:
- Includes an extensive list of common abbreviations and acronyms used in aviation, providing their meanings, and offers downloadable PDFs for easy reference.
Weather Decoding Guide:
- A section dedicated to weather decoding, including weather products, symbols, abbreviations, and terms relevant to aviation meteorology, ensuring pilots understand how to interpret weather information.
Aviation Definitions:
- Provides definitions for terms frequently used in aviation, particularly within the remotely piloted aircraft systems (RPAS) industry.

This page serves as a valuable resource for aviation professionals, offering the tools to decode NOTAMs and the necessary terminology to understand aviation communications effectively.

NOTAM Decoding

Notam Decoding Example

C357/24 REVIEW C355/24

OBST CRANE (LIT) 277FT AMSL ERECTED BRG 256 MAG 2.3NM FM ARP INFRINGES INNER HORIZONTAL SFC BY 83FT FROM 09 240139 TO 09 270600 DAILY 2000-0600

Detailed Breakdown

NOTAM Number:
- C357/24: This means it’s the 357th NOTAM for this location in 2024.
- REVIEW C355/24: This indicates that it is an update or review of another NOTAM previously issued (C355/24).
Subject:
- OBST CRANE (LIT) 277FT AMSL ERECTED:
  - OBST means “Obstacle.”
  - CRANE refers to the type of obstacle.
  - (LIT) indicates that the crane is illuminated.
  - 277FT AMSL means the crane’s height is 277 feet above mean sea level.
Location Details:
- BRG 256 MAG 2.3NM FM ARP:
  - BRG stands for “Bearing,” which in this case is 256 degrees magnetic.
  - 2.3NM means 2.3 nautical miles.
  - FM ARP: This means “From Aerodrome Reference Point,” which is a fixed point at the airport used as a reference.
Surface Infringement:
- INFRINGES INNER HORIZONTAL SFC BY 83FT:
  - INFRINGES means the crane is extending into the designated airspace.
  - INNER HORIZONTAL SFC refers to the inner horizontal surface of the airport, which is an imaginary plane established for obstacle clearance.
  - BY 83FT means the crane is 83 feet above the allowable height in that airspace.
Time and Validity:
- FROM 09 240139 TO 09 270600:
  - 09 240139 means it starts on September 24th at 0139 UTC.
  - 09 270600 means it ends on September 27th at 0600 UTC.
- DAILY 2000-0600: This indicates that the crane is operational (and potentially a hazard) daily between 2000 UTC and 0600 UTC.

Final Decoding

“A lit crane, 277 feet AMSL, has been erected 2.3 NM from Archerfield’s aerodrome reference point at a bearing of 256° magnetic. It infringes the inner horizontal surface by 83 feet. The crane will be in place from 24th September 0139 UTC to 27th September 0600 UTC, operational daily from 2000 UTC to 0600 UTC.”

Key Considerations During Decoding

Standard ICAO Abbreviations and Terms:
- Familiarity with aviation terminology, acronyms, and abbreviations such as “RWY” (Runway), “OBST” (Obstacle), “AMSL” (Above Mean Sea Level), and “BRG” (Bearing) is essential for decoding.
Time Conversions:
- NOTAM times are usually provided in UTC, so understanding and converting these times is crucial, especially if different time zones are mentioned (e.g., EST). In this case, times were left in UTC since no explicit conversion was requested.
Understanding Airspace and Obstacle Infringements:
- Recognizing terms like “Inner Horizontal Surface” and how obstacles infringe on it helps assess the impact on flight operations. These surfaces are established to ensure safe clearance around aerodromes.
Review and Update References:
- The second NOTAM referenced a review of another NOTAM (C355/24), indicating that the situation had been updated or re-evaluated.

Why This Detailed Decoding is Important for Pilots and Operators

Safety: Accurate decoding of NOTAMs ensures pilots are aware of potential hazards, such as closed runways or obstacles.
Operational Planning: Knowing about runway closures or obstacles allows for better pre-flight planning, route adjustments, and safety protocols.
Compliance: Following NOTAM instructions is mandatory for safe and legal flight operations, especially for controlled aerodromes.

This complete breakdown showcases the importance of understanding the detailed language, terminology, and timing information in NOTAMs for effective flight planning and safety.

There area a few different websites that can decode NOTAMs for you such as DRORPILOT, however it is suggested to get familiar with decoding NOTAMs without this aid as there may be situations where it will not be accessible.

Below is a list of abbreviations that included in NOTAMs additionally a PDF version can be downloaded HERE.

Acronym	Digital Notam Format	Meaning
A	amber	amber
A/A	a/a	air-to-air
A/G	a/g	air-to-ground
AAD	assigned altitude deviation	assigned altitude deviation
AAIM	Aircraft Autonomous Integrity Monitoring	Aircraft Autonomous Integrity Monitoring
AAL	Above Aerodrome Level	Above Aerodrome Level
AAR	air to air refuelling	air to air refuelling
ABI	advance boundary information	advance boundary information
ABM	abeam	abeam
ABN	ABN	Aerodrome Beacon
ABT	about	about
ABV	…or above	…or above
ACARS	ACARS	Aircraft communication addressing and reporting system
ACAS	ACAS	Airborne collision avoidance system
ACC	ACC	Area Control Center
ACCID	aircraft accident	notification of an aircraft accident
ACFT	acft	aircraft
ACK	ack	acknowledge
ACL	ACL	Altimeter check location
ACN	ACN	Aircraft classification number
ACP	acceptance	acceptance
ACPT	accept	accept
ACT	active, activated, activity	active, activated, activity
AD	AD	Aerodrome
ADA	Advisory Area	Advisory Area
ADC	Aerodrome Chart	Aerodrome Chart
ADDN	additional, addition	additional, addition
ADF	ADF	Automatic Direction-Finding Equipment
ADIZ	ADIZ	Air Defence Identification Code
ADJ	adjacent	adjacent
ADO	aerodrome office	aerodrome office
ADR	advisory route	advisory route
ADS	the address	the address
ADS-B	ADS-B	Automatic Dependent Surveillance – Broadcast
ADS-C	ADS-C	Automatic Dependent Surveillance – Contract
ADSU	ADSU	Automatic Dependent Surveillance Unit
ADVS	advisory service	advisory service
ADZ	advise	advise
AES	aircraft earth station	aircraft earth station
AFIL	AFIL	Flight Plan Filed in the Air
AFIS	AFIS	Aerodrome Flight Information Service
AFM	affirm, affirmative	affirm, affirmative
AFS	Aeronautical Fixed Service	Aeronautical Fixed Service
AFT	after	after
AFTN	AFTN	Aeronautical Fixed Telecommunication Network
AGA	AGA	Aerodromes, Air Routes and Ground Aids
AGL	AGL	Above Ground Level
AGN	again	again
AIC	AIC	Aeronautical Information Circular
AIDC	air traffic services interfacility data communications	air traffic services interfacility data communications
AIM	Aeronautical Information Management	Aeronautical Information Management
AIP	AIP	Aeronautical Information Publication
AIRAC	AIRAC	Aeronautical Information Regulation and Control
AIREP	air-report	air-report
AIRMET	AIRMET	Information concerning en-route weather phenomena which may affect the safety of low-level aircraft operations
AIS	AIS	Aeronautical Information Services
ALA	alighting area	alighting area
ALERFA	ALERFA	Alert Phase
ALR	alerting	alerting
ALRS	alerting service	alerting service
ALS	Approach Lighting System	Approach Lighting System
ALT	ALT	Altitude
ALTN	altn	alternate (aerodrome), alternating (light colour)
AMA	Area Minimum ALT	Area Minimum ALT
AMD	amend, amended	amend, amended
AMDT	AMDT	Amendment (AIP Amendment)
AMS	aeronautical mobile service	aeronautical mobile service
AMSL	AMSL	Above Mean Sea Level
AMSS	aeronautical mobile satellite service	aeronautical mobile satellite service
ANC	ANC	Aeronautical Chart – 1:500.000 (followed by name/title)
ANCS	ANCS	Aeronautical Navigation Chart – Small Scale (followed by name/title and scale)
ANS	answer	answer
AO	AO	Aircraft operator
AOC	AOC	Aerodrome obstacle chart (followed by name/title)
AP	airport	airport
APAPI	APAPI	(to be pronounced “AY-PAPI”)Abbreviated Precision Approach Path Indicator
APCH	apch	approach
APDC	APDC	Aircraft parking/docking chart (followed by name/title)
APN	apron	apron
APP	APP	Approach Control Office OR Approach Control OR Approach Control Service
APR	APR	April
APRX	aprx	approximate or approximately
APSG	after passing	after passing
APU	APU	Auxiliary power unit
APV	APV	Approach Procedure with Vertical guidance
APV	approve, approved, approval	approve, approved, approval
ARC	Area Chart	Area Chart
ARNG	arrange	arrange
ARO	ARO	Air traffic services reporting office
ARP	ARP	Aerodrome Reference Point
ARP	air-report	air-report
ARQ	automatic error correction	automatic error correction
ARR	arr	arrive or arrival
ARS	special air-report	special air-report
ARST	arresting	arresting
ASAP	asap	as soon as possible
ASC	ascend to, ascending to	ascend to, ascending to
ASDA	ASDA	Accelerate-Stop Distance Available
ASE	altimetry system error	altimetry system error
ASHTAM	ASHTAM	ASHTAM
ASPH	asph	asphalt
AT-VASIS	AT-VASIS	AT Visual Approach Slope Indicator System
ATA	ATA	Actual Time of Arrival
ATC	ATC	Air Traffic Control (in general)
ATCSMAC	ATC Surveillance Minimum ALT Chart	ATC Surveillance Minimum ALT Chart
ATD	ATD	Actual Time of Departure
ATFM	ATFM	Air Traffic Flow Management
ATIS	ATIS	Automatic Terminal Information Service
ATM	ATM	Air Traffic Management
ATN	ATN	Aeronautical Telecommunication Network
ATP	at… time or place	at… time or place
ATS	ATS	Air Traffic Services
ATTN	attn	attention
ATZ	ATZ	Aerodrome Traffic Zone
AUG	AUG	August
AUTH	auth	authorized, authorization
AUTO	auto	automatic
AUW	all up weight	all up weight
AUX	auxiliary	auxiliary
AVBL	available	available
AVG	average	average
AVGAS	avgas	aviation gasoline
AWOS	AWOS	Automated Weather Observation System
AWTA	advise at what time able	advise at what time able
AWY	AWY	Airway
AZM	azm	azimuth
B	blue	blue
BA	braking action (not each word in upper)	braking action (not each word in upper)
BARO-VNAV	BARO-VNAV	Barometric vertical navigation
BASE	cloud base	cloud base
BCN	bcn	beacon (aeronautical ground light)
BCST	broadcast	broadcast
BDRY	bdry	boundary
BECMG	becoming	becoming
BFR	before	before
BKN	broken	broken
BLDG	building	building
BLO	below clouds	below clouds
BLW	below	below
BOMB	bombing	bombing
BRF	short	short
BRG	BRG	Bearing
BRKG	breaking	breaking
BS	commercial broadcasting station	commercial broadcasting station
BTL	between layers	between layers
BTN	between	between
C	C	Centre (preceded by runway designation number to identify a parallel RWY)
C	C	Degrees Celsius (Centigrade)
C	C	degrees Celsius
CA	course to an altitude	course to an altitude
CAA	CAA	Civil Aviation Authority or Civil Aviation Administration
CAT	CAT	Category
CAT	clear air turbulence	clear air turbulence
CAVOK	CAVOK	Visibility, cloud and present weather better than prescribed values or conditions
CD	candela	candela
CDO	Continuous Descent Operations	Continuous Descent Operations
CDR	CDR	Conditional route
CF	change frequency to	change frequency to
CF	course to a fix	course to a fix
CFM	confirm	confirm
CGL	circling guidance lights	circling guidance lights
CH	CH	Channel
CH#	channel	channel
CHEM	chem	chemical
CIDIN	CIDIN	Common ICAO Data Interchange Network
CIV	civil	civil
CK	check	check
CL	centre line	centre line
CLA	clear type of ice formation	clear type of ice formation
CLBR	calibration	calibration
CLD	cloud	cloud
CLG	calling	calling
CLIMB-OUT	climb-out area	climb-out area
CLR	cleared, clear, clearance	cleared, clear, clearance
CLRD	RWY cleared	RWY cleared
CLSD	close, closed, closing	close, closed, closing
CMB	climb, climbing to	climb, climbing to
CMPL	completion, complete,completed	completion, complete,completed
CNL	cancel, cancelled	cancel, cancelled
CNS	CNS	Communications, Navigation and Surveillance
COM	COM	Communications
CONC	concrete	concrete
COND	cond	condition
CONS	continuous	continuous
CONST	construction, constructed	construction, constructed
CONT	cont	continue(s) , continued
COOR	coor	coordinate, coordination
COORD	coord	coordinates
COP	change-over point	change-over point
COT	at the coast	at the coast
COV	cover	cover
CPDLC	CPDLC	Controller-Pilot Data Link Communications
CPL	current flight plan	current flight plan
CRC	Cyclic Redundancy Check	Cyclic Redundancy Check
CRM	collision risk model	collision risk model
CRP	Compulsory Reporting Point	Compulsory Reporting Point
CRZ	cruise	cruise
CS	CS	Call sign
CTA	CTA	Control Area
CTAM	climb and maintain	climb and maintain
CTC	contact	contact
CTL	control	control
CTN	caution	caution
CTR	CTR	Control Zone
CUST	customs	customs
CVR	cockpit voice recorder	cockpit voice recorder
CW	continuous wave	continuous wave
CWY	CWY	Clearway
D	downward	downward
D	Danger Area	Danger Area
D-ATIS	D-ATIS	Data Link Automatic Terminal Information Service
D-VOLMET	D-VOLMET	Data Link VOLMET
D….	D….	Danger area (followed by Identification)
DA	DA	Decision Altitude
DCD	double channel duplex	double channel duplex
DCKG	dckg	docking
DCP	datum crossing point	datum crossing point
DCPC	Direct Controller-Pilot Communication	Direct Controller-Pilot Communication
DCS	double channel simplex	double channel simplex
DCT	DCT	Direct
DEC	DEC	December
DEG	DEG	Degrees
DEP	DEP	Departure (message type designator)
DEP	departure, depart	departure, depart
DEPO	deposition	deposition
DER	departure end of RWY	departure end of RWY
DES	descend, descending	descend, descending
DEST	dest	destination
DETRESFA	DETRESFA	Distress Phase
DEV	deviation, deviating	deviation, deviating
DF	DF	Direction Finding
DFDR	digital flight data recorder	digital flight data recorder
DFTI	distance from touchdown indication	distance from touchdown indication
DH	DH	Decision Height
DIF	diffuse	diffuse
DIST	dist	distance
DIV	divert, diverting	divert, diverting
DLA	DLA	Delay (message type designator)
DLA	delay, delayed	delay, delayed
DLIC	data link initiation capability	data link initiation capability
DLY	daily	daily
DME	DME	Distance Measuring Equipment
DNG	danger, dangerous	danger, dangerous
DOF	date of flight	date of flight
DOM	domestic	domestic
DP	dew point temperature	dew point temperature
DPT	depth	depth
DR	dead reckoning	dead reckoning
DRG	during	during
DSB	double sideband	double sideband
DTAM	descend to and maintain	descend to and maintain
DTG	date-time-group	date-time-group
DTHR	displaced THR	displaced THR
DTRT	deteriorate, deteriorating	deteriorate, deteriorating
DTW	dual tandem wheels	dual tandem wheels
DUC	dense upper cloud	dense upper cloud
DUPE#	duplicated message	duplicated message
DUR	duration	duration
DVOR	DVOR	Doppler VOR
DW	dual wheels	dual wheels
E	E	Eastern Longitude
E	east	east
EAT	expected approach time	expected approach time
EB	eastbound	eastbound
EDA	elevation differential area	elevation differential area
EET	estimated elapsed time	estimated elapsed time
EFC	expected further clearance	expected further clearance
EFIS	electronic flight instrument systems	electronic flight instrument systems
EGNOS	EGNOS	European Geostationary Navigation Overlay Service
EHF	EHF	Extremely High Frequency (30000 to 300000 MHz)
ELBA	ELBA	Emergency Location Beacon – Aircraft
ELEV	elev	elevation
ELR	extra long range	extra long range
ELT	ELT	Emergency Locator Transmitter
EM	emission	emission
EMBD	embedded	embedded
EMERG	EMERG	Emergency
END	stop-end	stop-end
ENE	east-north-east	east-north-east
ENG	engine	engine
ENR	ENR	En route
ENRC	ENRC	Enroute chart (followed by name/title)
EOBT	EOBT	Estimated Off-Block Time
EQPT	eqpt	equipment
ESE	east-south-east	east-south-east
EST	EST	Estimate OR Estimated OR Estimation (message type designator)
ETA	ETA	Estimated Time of Arrival OR Estimating Arrival
ETD	ETD	Estimated Time of Departure OR Estimating Departure
ETO	ETO	Estimated Time Over Significant Point
EV	every	every
EVS	enhanced vision system	enhanced vision system
EXC	except	except
EXER	exercises, exercising, exercise	exercises, exercising, exercise
EXP	expect	expect
EXTD	extd	extend or extending
F	fixed	fixed
FA	FA	Course from a fix to an altitude
FAC	fac	facilities
FAF	FAF	Final Approach Fix
FAL	FAL	Facilitation of International Air Transport
FAP	FAP	Final Approach Point
FAS	FAS	Final Approach Segment
FATO	FATO	Final Approach and Take-off Area
FAX	fax	facsimile transmission
FCST	fcst	forecast
FCT	friction coefficient	friction coefficient
FDPS	flight data processing system	flight data processing system
FEB	FEB	February
FIC	FIC	Flight Information Centre
FIR	FIR	Flight Information Region
FIS	FIS	Flight Information Service
FISA	Use ‘Automated FIS’ instead.	Use ‘Automated FIS’ instead.
FL	FL	Flight Level
FLG	FLG	Flashing
FLT	flight, flights	flight, flights
FLTCK	flight check	flight check
FLUC	fluctuating, fluctuation, fluctuated	fluctuating, fluctuation, fluctuated
FLW	follows, following	follows, following
FLY	fly, flying	fly, flying
FM	fm	from
FM	from	from
FMC	Flight Management Computer	Flight Management Computer
FMS	Flight Management System	Flight Management System
FMU	Flow Management Unit	Flow Management Unit
FNA	final approach	final approach
FPAP	flight path alignment point	flight path alignment point
FPL	FPL	Flight Plan
FPM	feet per minute	feet per minute
FPR	fligh plan route	fligh plan route
FR	fuel remaining	fuel remaining
FREQ	freq	frequency
FRI	FRI	Friday
FRNG	frng	firing
FRQ	frequent	frequent
FSL	full stop landing	full stop landing
FSS	flight service station	flight service station
FST	first	first
FT	ft	foot/feet
FTE	flight technical error	flight technical error
FTT	flight technical tolerance	flight technical tolerance
G	green	green
G/A	g/a	ground-to-air
G/A/G	g/a/g	ground-to-air and air-to-ground
GA	GA	General Aviation
GA	go ahead, resume sending	go ahead, resume sending
GAGAN	GAGAN	GPS & Geostationary Earth Orbit Augmented Navigation
GAIN	airspeed or headwind gain	airspeed or headwind gain
GARP	GBAS azimuth reference point	GBAS azimuth reference point
GBAS	GBAS	Ground Based Augmentation System
GCA	Ground Controlled APP	Ground Controlled APP
GEN	GEN	General
GEO	GEO	Geographic OR True
GES	Ground Earth Station	Ground Earth Station
GLD	glider	glider
GLONAS	GLONAS	Global Orbiting Navigation Satellite System (to be pronounced “GLO-NAS”)
GLS	GLS landing system	GLS landing system
GMC	Ground Movement Chart	Ground Movement Chart
GND	GND	Ground
GNDCK	ground check	ground check
GNSS	GNSS	Global Navigation Satellite System
GOV	GOV	Government
GP	GP	Glide Path
GPA	glide path angle	glide path angle
GPIP	glide path intercept point	glide path intercept point
GPS	GPS	Global Positioning System
GPU	Ground Power Unit	Ground Power Unit
GPWS	Ground Proxmity Warning Area	Ground Proxmity Warning Area
GRAS	ground based regional augmentation system	ground based regional augmentation system
GRASS	Grass Landing Area	Grass Landing Area
GRVL	gravel	gravel
GS	GS	Ground Speed
GUND	geoid undulation	geoid undulation
H24	H24	Continuous Day and Night Service
HA	holding/racetrack to an altitude	holding/racetrack to an altitude
HAPI	HAPI	Helicopter Approach Path Indicator
HBN	hazard beacon	hazard beacon
HDF	HDF	High Frequency Direction-Finding Station
HDG	HDG	Heading
HEL	hel	helicopter
HF	HF	High Frequency [3000 to 30000 kHz]
HF	holding/racetrack to a fix	holding/racetrack to a fix
HGT	hgt	height or height above
HJ	HJ	Sunrise to sunset
HLDG	holding	holding
HLP	heliport	heliport
HLS	heliport landing site	heliport landing site
HM	holding/racetrack to a manual termination	holding/racetrack to a manual termination
HN	HN	Sunset to Sunrise
HO	HO	Service available to meet operational requirements
HOL	HOL	Holiday
HOSP	HOSP	Hospital Aircraft
HPA	hPa	hectopascal
HR	HR	hour
HS	HS	Service Available During Hours of Scheduled Operations
HUD	head-up display	head-up display
HUM	HUM	Humanitarian
HVDF	HVDF	High and Very High Frequency Direction Finding Stations (At the Same Location)
HVY	heavy	heavy
HX	HX	No Specific Working Hours
HYR	higher	higher
HZ	Hz	hertz
IAC	IAC	Instrument Approach Chart (followed by name/title)
IAF	IAF	Initial Approach Fix
IAO	in and out of clouds	in and out of clouds
IAP	IAP	Instrument Approach Procedure
IAR	intersection of air routes	intersection of air routes
IAS	IAS	Indicated Air Speed
IBN	identification beacon	identification beacon
ICAO	ICAO	International Civil Aviation Organization
ID	ID	Identifier OR Identify
IDENT	ident	identification
IF	IF	Intermediate Approach Fix
IFF	identification friend/foe	identification friend/foe
IFR	IFR	Instrument Flight Rules
IGA	international general aviation	international general aviation
ILS	ILS	Instrument Landing System
IM	IM	Inner marker
IMC	IMC	Instrument Meteorological Conditions
IMG	immigration	immigration
IMPR	improving, improve	improving, improve
IMT	immediate, immediately	immediate, immediately
INA	intital approach	intital approach
INBD	inbound	inbound
INC	in cloud	in cloud
INCERFA	INCERFA	Uncertainty Phase
INCORP	incorp	incorporated
INFO	info	information
INOP	inop	inoperative
INP	if not possible	if not possible
INPR	in progress	in progress
INS	INS	Inertial Navigation System
INSTL	installed	installed
INSTR	instr	instrument
INT	intersection	intersection
INTL	intl	international
IRS	IRS	Inertial reference system
ISA	ISA	International Standard Atmosphere
ISB	independent sideband	independent sideband
ISOL	isolated	isolated
JAN	JAN	January
JTST	jetstream	jetstream
JUL	JUL	July
JUN	JUN	June
KG	kg	kilogram
KIAS	KIAS	Knots indicated airspeed
KM	km	kilometer
KMH	kmh	kilometer per hour
KPA	kPa	kilopascal
KT	kt	knots
KW	kW	kilowatt
L	L	Left (preceded by runway designation number to identify a parallel runway)
L	L	Locator (See LM, LO)
LAN	inland	inland
LAT	lat	latitude
LCA	local, located, location, locally	local, located, location, locally
LDA	LDA	Landing Distance Available
LDAH	LDAH	Landing Distance Available, Helicopter
LDG	ldg	landing
LDI	LDI	Landing Direction Indicator
LEN	length	length
LF	LF	Low Frequency (30 to 300 kHz)
LGT	light or lighting	light or lighting
LGTD	lighted	lighted
LIH	LIH	Light Intensity High
LIL	LIL	Light Intensity Low
LIM	LIM	Light Intensity Medium
LITRE	litre	litre
LM	LM	Locator, Middle
LMT	local mean time	local mean time
LNAV	LNAV	Lateral Navigation (to be pronounced “EL-NAV”)
LNG	long	long
LO	LO	Locator, Outer
LOC	LOC	Localizer
LONG	long	longitude
LORAN	LORAN	LORAN (Long Range Air Navigation System)
LOSS	airspeed or headwind loss	airspeed or headwind loss
LPV	LPV	Localizer Performance with Vertical Guidance
LRG	long range	long range
LTA	Lower Control Area	Lower Control Area
LTD	limited	limited
LTP	landing thr point	landing thr point
LVE	leave, leaving	leave, leaving
LVL	level	level
LVP	LVP	Low Visibility Procedures
LYR	layer, layered	layer, layered
M	M	Mach Number (Followed by figures)
M	m	metre
MAA	Max Authorised ALT	Max Authorised ALT
MAG	MAG	Magnetic
MAHF	missed approach holding fix	missed approach holding fix
MAINT	maint	maintenance
MAP	MAP	Aeronautical maps and charts
MAPT	MAPT	Missed Approach Point
MAR	MAR	March
MAR	at sea	at sea
MATF	missed approach turning fix	missed approach turning fix
MATZ	MATZ	Military Aerodrome Traffic Zone
MAX	max	maximum
MAY	MAY	May
MBST	microburst	microburst
MCA	Minimum Crossing ALT	Minimum Crossing ALT
MCTR	MCTR	Military Control Zone
MCW	modulated continuous wave	modulated continuous wave
MDA	MDA	Minimum Descent Altitude
MDF	medium frequency direction finding station	medium frequency direction finding station
MDH	MDH	Minimum Descent Height
MEA	Miminum ENR ALT	Miminum ENR ALT
MEDEVAC	MEDEVAC	Medical Evacuation Flight
MEHT	MEHT	Minimum Eye Height over Threshold (For VASIS and PAPI)
MET	MET	Meteorological OR Meteorology
METAR	METAR	Aerodrome routine meteorological report
MF	MF	Medium Frequency (300 to 3000 kHz)
MHA	Minimum Holding ALT	Minimum Holding ALT
MHDF	medium and high frequency direction finding stations	medium and high frequency direction finding stations
MHVDF	medium, high and very high frequency direction finding stations	medium, high and very high frequency direction finding stations
MHZ	MHz	megahertz
MID	mid-point	mid-point
MIL	MIL	Military
MIN	min	minute
MKR	MKR	Marker radio beacon
MLS	MLS	Microwave Landing System
MM	MM	Middle Marker
MNM	mnm	minimum
MNPS	Minimum Navigation Performance Specifications	Minimum Navigation Performance Specifications
MNT	monitor, monitoring, monitored	monitor, monitoring, monitored
MNTN	maintain	maintain
MOA	MOA	Military Operating Area
MOC	MOC	Minimum Obstacle Clearance (required)
MOCA	Minimum Obstacle Clearance ALT	Minimum Obstacle Clearance ALT
MON	MON	Monday
MON	above mountains	above mountains
MOPS	minimum operational performance standards	minimum operational performance standards
MOV	mov	move , moving, movement
MPS	mps	metres per second
MRA	Minimum Reception ALT	Minimum Reception ALT
MRG	medim range	medim range
MS	minus	minus
MSA	Minimum Sector ALT	Minimum Sector ALT
MSAS	Multifunctional Transport Satellite Satellite-based Augmentation System	Multifunctional Transport Satellite Satellite-based Augmentation System
MSAW	minimum safety altitude warning	minimum safety altitude warning
MSG	msg	message
MSL	MSL	Mean Sea Level
MSSR	MSSR	Monopulse Secondary Surveillance Radar
MT	mountain	mountain
MTOM	maximum take-off mass	maximum take-off mass
MTU	metric units	metric units
MTW	moutain waves	moutain waves
MVDF	medium and very high hrequency direction finding stations	medium and very high hrequency direction finding stations
MWO	MWO	Meteorological Watch Office
N	north	north
N	no distinct tendency	no distinct tendency
NADP	noise abatement departure procedure	noise abatement departure procedure
NASC	national AIS system centre	national AIS system centre
NAT	NAT	North Atlantic
NAV	nav	navigation
NAVAID	navaid	navigation aid
NB	northbound	northbound
NBFR	not before	not before
NC	no change	no change
NDB	NDB	Non-Directional Radio Beacon
NE	north-east	north-east
NEB	north-eastbound	north-eastbound
NEG	negative	negative
NGT	night	night
NIL	NIL	None OR I Have nothing to send to you
NM	NM	nautical mile
NML	normal	normal
NN	no name, unnamed	no name, unnamed
NNE	north-north-east	north-north-east
NNW	north-north-west	north-north-west
NOF	NOF	International NOTAM Office
NONSTD	nonstd	non-standard
NOSIG	nosig	no significant change
NOTAMC	NOTAMC	Cancelling NOTAM
NOTAMN	NOTAMN	New NOTAM
NOTAMR	NOTAMR	Replacing NOTAM
NOV	NOV	November
NOZ	Normal Operating Zone	Normal Operating Zone
NPA	NPA	Non-precision approach
NR	nr	number
NRH	no reply heard	no reply heard
NSE	navigation system error	navigation system error
NSW	nil significant weather	nil significant weather
NTL	ntl	national
NTZ	No Transgression Zone	No Transgression Zone
NW	north-west	north-west
NWB	north-westbound	north-westbound
NXT	next	next
O/R	o/r	on request
OAC	OAC	Oceanic Area Control Centre
OAS	Obstacle Assessment Surface	Obstacle Assessment Surface
OBS	obs	observe, observed, observation
OBSC	obscure, obscured, obscuring	obscure, obscured, obscuring
OBST	obst	obstacle
OCA	OCA	Obstacle Clearance Altitude
OCA	Oceanic Control Area	Oceanic Control Area
OCC	occulting	occulting
OCH	OCH	Obstacle Clearance Height
OCNL	occasional, occasionally	occasional, occasionally
OCS	Obstacle Clearance Surface	Obstacle Clearance Surface
OCT	OCT	October
OFZ	Obstacle Free Zone	Obstacle Free Zone
OHD	overhead	overhead
OIS	Obstacle Identification Surface	Obstacle Identification Surface
OLDI	OLDI	On-Line Data Interchange
OM	OM	Outer Marker
OPC	the control indicated is operational control	the control indicated is operational control
OPMET	OPMET	Operational Meteorological (information)
OPN	open	open
OPR	operator, operate, operative	operator, operate, operative
OPS	ops	operations
ORD	order	order
OSV	ocean station vessel	ocean station vessel
OTP	on top	on top
OTS	Organised Track System	Organised Track System
OUBD	outbound	outbound
OVC	overcast	overcast
P	Prohibited Area	Prohibited Area
P…	P…	Prohibited area (followed by identification)
PA	precision approach	precision approach
PALS	Precision Approach Lighting System	Precision Approach Lighting System
PANS	PANS	Procedures for Air Navigation Services
PAPI	PAPI	Precision Approach Path Indicator
PAR	PAR	Precision Approach Radar
PARL	parallel	parallel
PATC	PATC	Precision Approach Terrain Chart (followed by name/title)
PAX	pax	passenger(s)
PBN	PBN	Performance-based navigation
PCD	proceed, proceeding	proceed, proceeding
PCL	pilot-controlled lighting	pilot-controlled lighting
PCN	PCN	Pavement Classification Number
PCT	per cent	per cent
PDC	pre-departure clearance	pre-departure clearance
PDG	procedure design gradient	procedure design gradient
PER	performance	performance
PERM	perm	permanent
PIB	PIB	Pre-flight Information Bulletin
PJE	parachute jumping exercise	parachute jumping exercise
PLA	practice low approach	practice low approach
PLVL	present level	present level
PN	prior notice required	prior notice required
PNR	point of no return	point of no return
POB	persons on board	persons on board
POSS	possible	possible
PPI	plan position indicator	plan position indicator
PPR	PPR	Prior Permission Required
PPSN	present position	present position
PRI	primary	primary
PRKG	parking	parking
PROB	prob	probability
PROC	proc	procedure
PROP	prop	propeller
PROV	provisional	provisional
PRP	point-in-space reference point	point-in-space reference point
PS	plus	plus
PSG	passing	passing
PSN	position	position
PSP	pierced steel plank	pierced steel plank
PSR	PSR	Primary Surveillance Radar
PSYS	pressure system(s)	pressure system(s)
PTN	procedure turn	procedure turn
PTS	Polar Track Structure	Polar Track Structure
PWR	pwr	power
QDM	QDM	Magnetic Heading (zero wind)
QDR	QDR	Magnetic Bearing
QFE	QFE	Atmospheric pressure at aerodrome elevation (OR at runway threshold)
QNH	QNH	Altimeter sub-scale setting to obtain elevation when on the ground
QTE	QTE	True bearing
QUAD	quadrant	quadrant
R	R	Right (preceded by runway designation number to identify a parallel runway)
R	red	red
R	rate of turn	rate of turn
R	Restricted Area	Restricted Area
R-NNN	R-nnn	Radial from VOR (followed by three figures)
R…	R…	Restricted area (followed by identification)
RA	resolution advisory	resolution advisory
RAC	RAC	Rules of the Air and Air Traffic Services
RAG	ragged	ragged
RAG	RWY arresting gear	RWY arresting gear
RAI	RWY alignment indicator	RWY alignment indicator
RAIM	RAIM	Receiver Autonomous Integrity Monitoring
RASC	Regional AIS System Centre	Regional AIS System Centre
RASS	Remote Altimeter Setting Source	Remote Altimeter Setting Source
RB	rescue boat	rescue boat
RCA	Reach Cruising ALT	Reach Cruising ALT
RCC	RCC	Rescue Co-ordination Centre
RCH	reach, reaching	reach, reaching
RCL	RWY centre line	RWY centre line
RCLL	RWY centre line light(s)	RWY centre line light(s)
RCLR	recleared	recleared
RCP	required communication performance	required communication performance
RDH	RDH	Reference Datum Height
RDL	radial	radial
RDO	radio	radio
REC	receive, receiver	receive, receiver
REDL	RWY edge light(s)	RWY edge light(s)
REF	ref	reference to, refer to
REG	reg	registration
RENL	RWY end light(s)	RWY end light(s)
REP	rep	report, reporting, reporting point
REQ	req	request, requested
RESA	RESA	Runway End Safety Area
RFFS	Rescue and Fire Fighting Services	Rescue and Fire Fighting Services
RG	range	range
RHC	right-hand circuit	right-hand circuit
RIF	reclearance in flight	reclearance in flight
RL	report leaving	report leaving
RLA	relay to	relay to
RLCE	request level change en-route	request level change en-route
RLLS	RWY lead-in lighting system	RWY lead-in lighting system
RLNA	requested level not available	requested level not available
RMK	rmk	remark
RNAV	RNAV	Area Navigation (to be pronounced “AR-NAV”)
RNG	radio range	radio range
RNP	RNP	Required Navigation Performance
ROC	rate of climb	rate of climb
ROD	rate of descent	rate of descent
RON	receiving only	receiving only
RPDS	reference path data selector	reference path data selector
RPI	radar position Indicator	radar position Indicator
RPL	RPL	Repetitive flight plan
RPLC	replace, replaced	replace, replaced
RPS	Radar Position Symbol	Radar Position Symbol
RQMNTS	requirements	requirements
RQP	RQP	Request flight plan (message type designator)
RQS	RQS	Request supplementary flight plan (message type designator)
RR	report reaching	report reaching
RSC	rescue sub-centre	rescue sub-centre
RSCD	runway surface condition	runway surface condition
RSP	responder beacon	responder beacon
RSR	RSR	En-Route Surveillance Radar
RSS	root sum square	root sum square
RTE	rte	route
RTF	radiotelephone	radiotelephone
RTG	radiotelegraph	radiotelegraph
RTHL	RWY THR light(s)	RWY THR light(s)
RTN	return, returned, returning	return, returned, returning
RTODAH	rejected take-off distance available, helicopter	rejected take-off distance available, helicopter
RTS	return to service	return to service
RTT	radioteletypewriter	radioteletypewriter
RTZL	RWY touchdown zone light(s)	RWY touchdown zone light(s)
RUT	standard regional route transmitting frequencies	standard regional route transmitting frequencies
RV	rescue vessel	rescue vessel
RVA	RWY Vectoring Area	RWY Vectoring Area
RVR	RVR	Runway Visual Range
RVSM	RVSM	Reduced Vertical Separation Minimum
RWY	RWY	Runway
S	south	south
SALS	Simple Approach Lighting Systems	Simple Approach Lighting Systems
SAN	sanitary	sanitary
SAR	SAR	Search and Rescue
SARPS	SARPS	Standards and Recommended Practices ICAO
SAT	SAT	Saturday
SATCOM	SATCOM	Satellite Communication
SB	southbound	southbound
SBAS	SBAS	Satellite Based Augmentation System (to be pronounced “ESS-BAS”)
SD	standard deviation	standard deviation
SDBY	stand by	stand by
SDF	step down fix	step down fix
SE	south-east	south-east
SEB	south-eastbound	south-eastbound
SEC	sec	second
SECN	section	section
SECT	sector	sector
SELCAL	SELCAL	Selective calling system
SEP	SEP	September
SER	service	service
SFC	SFC	Surface
SGL	signal	signal
SHF	SHF	Super High Frequency (3000 to 30000 MHz)
SI	SI	International system of units
SID	SID	Standard Instrument Departure
SIF	selective identification feature	selective identification feature
SIG	sig	significant
SIGMET	SIGMET	Information concerning en-route weather phenomena which may affect the safety of aircraft operations
SIMUL	simultaneous, simultaneously	simultaneous, simultaneously
SIWL	single isolated wheel load	single isolated wheel load
SLP	speed limiting point	speed limiting point
SLW	slow	slow
SMC	Surface Movement Control	Surface Movement Control
SMR	Surface Movement Radar	Surface Movement Radar
SNOWTAM	SNOWTAM	SNOWTAM
SOC	start of climb	start of climb
SPI	special position indicator	special position indicator
SPL	supplementary flight plan	supplementary flight plan
SPOC	SAR point of contact	SAR point of contact
SPOT	spot wind	spot wind
SR	SR	Sunrise
SRA	SRA	Surveillance Radar Approach
SRE	SRE	Surveillance Radar Element of precision approach radar system
SRG	short range	short range
SRR	SAR Region	SAR Region
SRY	secondary	secondary
SS	SS	Sunset
SS	sandstorm	sandstorm
SSB	single sideband	single sideband
SSE	south-south-east	south-south-east
SSR	SSR	Secondary Surveillance Radar
SST	supersonic transport	supersonic transport
SSW	south-south-west	south-south-west
STA	straight-in approach	straight-in approach
STAR	STAR	Standard instrument arrival
STD	STD	Standard
STN	stn	station
STOL	short take-off and landing	short take-off and landing
STS	sts	status
STWL	stopway lights	stopway lights
SUBJ	subj	subject to
SUN	SUN	Sunday
SUP	SUP	Supplement (AIP Supplement)
SUPPS	SUPPS	Regional supplementary procedures
SVCBL	serviceable	serviceable
SW	south-west	south-west
SWB	south-westbound	south-westbound
SWY	SWY	Stop way
T	temperature	temperature
T	TRUE	TRUE
T-VASIS	T-VASIS	T Visual Approach Slope Indicator System
TA	TA	Transition Altitude
TA	traffic advisory	traffic advisory
TA/H	TA/H	Turn at an altitude/height
TAA	Terminal Arrival ALT	Terminal Arrival ALT
TACAN	TACAN	UHF Tactical Air Navigation Aid
TAF	TAF	Aerodrome forecast
TAIL	tail wind	tail wind
TAR	TAR	Terminal Area Surveillance Radar
TAS	TAS	True Airspeed
TAX	taxiing, taxi	taxiing, taxi
TCASRA	TCASRA	Traffic alert and collision avoidance system resolution advisory
TCH	THR Crossing Height	THR Crossing Height
TDZ	TDZ	Touchdown Zone
TECR	technical reason	technical reason
TEL	tel	telephone
TEMPO	tempo	temporary, temporarily
TF	TF	Track to fix
TFC	tfc	traffic
TGL	tgl	touch-and-go landing
TGS	Taxiing Guidance System	Taxiing Guidance System
THR	THR	Threshold
THRU	through	through
THU	THU	Thursday
TIBA	Traffic Information Broadcast by Aircraft	Traffic Information Broadcast by Aircraft
TIL	until	until
TIP	until past… (place)	until past… (place)
TKOF	tkof	take-off
TLOF	tlof	touchdown and lift-off area
TMA	TMA	Terminal Control Area
TNA	turn altitude	turn altitude
TNH	turn height	turn height
TOC	top of climb	top of climb
TODA	TODA	Take-off Distance Available
TODAH	TODAH	Take-off Distance Available, Helicopter
TOP	cloud top	cloud top
TORA	TORA	Take-off Run Available
TOX	toxic	toxic
TP	TP	Turning Point
TR	track	track
TRA	Temporary Reserved Airspace	Temporary Reserved Airspace
TRL	TRL	Transition Level
TROP	tropopause	tropopause
TT	teletypewriter	teletypewriter
TUE	TUE	Tuesday
TURB	turb	turbulence
TVOR	TVOR	Terminal VOR
TWR	TWR	Aerodrome control tower OR aerodrome control
TWY	TWY	Taxiway
TWYL	taxiway-link	taxiway-link
TYP	type of aircraft	type of aircraft
U/S	unserviceable	unserviceable
UA	unmanned acft	unmanned acft
UAB	until advised by	until advised by
UAC	UAC	Upper Area Control Centre
UAR	Upper Air Route	Upper Air Route
UDF	UDF	Ultra High Frequency Direction Finding Station
UFN	ufn	until further notice
UHDT	unable higher due traffic	unable higher due traffic
UHF	UHF	Ultra High Frequency 300 to 3000 MHz
UIC	Upper Information Centre	Upper Information Centre
UIR	UIR	Upper Flight Information Region
ULM	ultralight motorized acft	ultralight motorized acft
ULR	ultra long range	ultra long range
UNA	unable	unable
UNAP	unable to approve	unable to approve
UNL	unlimited	unlimited
UNREL	unreliable	unreliable
UTA	UTA	Upper Control Area
UTC	UTC	Coordinated Universal Time
VA	VA	Volcanic Ash
VA	heading to an altitude	heading to an altitude
VAAC	VAAC	Volcanic Ash Advisory Centre
VAC	VAC	Visual Approach Chart
VAL	in valleys	in valleys
VAN	RWY control van	RWY control van
VAR	VAR	Magnetic Variation
VAR	visual-aural radio range	visual-aural radio range
VASIS	VASIS	Visual Approach Slope Indicator System
VCY	vicinity	vicinity
VDF	VDF	Very High Frequency Direction Finding Station
VER	vertical	vertical
VFR	VFR	Visual Flight Rules
VHF	VHF	Very High Frequency [30 to 300 MHz]
VI	heading to an intercept	heading to an intercept
VIP	VIP	Very Important Person
VIS	visibility	visibility
VLF	VLF	Very Low Frequency [3 to 30 KHz]
VLR	very long range	very long range
VM	heading to a manual termination	heading to a manual termination
VMC	VMC	Visual Meteorological Conditions
VNAV	VNAV	Vertical Navigation (to be pronounced “VEE-NAV”)
VOL	vol	volume (followed by I, II…)
VOLMET	VOLMET	Meteorological information for aircraft in flight
VOR	VOR	Very High Frequency Omnidirectional Radio Range
VORTAC	VORTAC	VOR and TACAN combination
VOT	VOR airborne equipment test facility	VOR airborne equipment test facility
VPA	vertical path angle	vertical path angle
VPT	visual manoeuvre with prescribed track	visual manoeuvre with prescribed track
VRB	vrb	variable
VSA	by visual reference to the ground	by visual reference to the ground
VSP	vertical speed	vertical speed
VTF	vector to final	vector to final
VTOL	VTOL	Vertical Take-Off and Landing
W	west	west
W	white	white
WAAS	WAAS	Wide Area Augmentation System
WAC	WAC	World Aeronautical Chart — ICAO 1:1 000 000 (followed by name/title)
WAFC	world area forecast centre	world area forecast centre
WB	westbound	westbound
WBAR	wing bar lights	wing bar lights
WDI	wdi	wind direction indicator
WDSPR	widespread	widespread
WED	WED	Wednesday
WEF	wef	with efffect from
WGS-84	WGS-84	World Geodetic System – 1984
WI	within	within
WID	width	width
WIE	wie	with immediate effect
WILCO	wilco	will comply
WIP	wip	work in progress
WKN	weaken, weakening	weaken, weakening
WNW	west-north-west	west-north-west
WO	without	without
WPT	WPT	Way-point
WRNG	wrng	warning
WS	windshear	windshear
WSPD	windspeed	windspeed
WSW	west-south-west	west-south-west
WT	weight	weight
WTSPT	waterspout	waterspout
WWW	www	worldwide web
WX	weather radar	weather radar
WX	weather	weather
X	cross	cross
XBAR	crossbar	crossbar
XNG	crossing	crossing
XS	atmospheric	atmospheric
Y	yellow	yellow
YCZ	Yellow Caution Zone	Yellow Caution Zone
YR	yr	your

Aviation Weather Decode Card

This Aviation Weather Decode Card provides a comprehensive guide to interpreting aviation weather reports, forecasts, and terminology. It includes a UTC conversion table, details on various weather products like SIGMET, ARFOR, TAF, TTF, METAR, SPECI, and ATIS, and explanations of weather symbols, abbreviations, and terms used in aviation meteorology. It serves as a quick reference for pilots and aviation professionals to understand weather conditions, forecasts, and alerts for safe flight operations. Weather Decoder Download.

Aviation Definitions

Aviation (like most industries) has a plethora of buzz words which are a source of constant intrigue to those outside of the industry. This page contains definitions for many of the regular terms used within the remotely piloted aircraft systems industry.

PDF Download can be found HERE.

Term	Deﬁnition
Advisory Circular (AC)	An AC is a document produced by the CASA which provides guidance and clariﬁcation as to acceptable means of complying with the intent of a piece of legislation. ACs may be found on the CASA Advisory Circulars web page.
Aeronautical Information Package (AIP)	The AIP is a collection of documents including aeronautical maps, charts and other publications which is produced by Airservices Australia to inform pilots of operational information.
Approved area	The area approved under regulation 101.030 as an area approved for the operation of remotely piloted aircraft (RPA).
Aviation Reference Number (ARN)	An ARN is a number assigned to an individual or organisation for use when dealing with the CASA.
Authority controlling the area	The entity that has control and has been authorised to manage that type of airspace, e.g.: Prohibited – the secretary to the Department of Defence. Restricted – the authority mentioned in the aeronautical information publication (as issued from time to time) as the controlling authority for the area. Danger area – the authority mentioned in the aeronautical information publication (as issued from time to time) as the controlling authority for the area.
Beyond Visual Line of Sight (BVLOS)	BVLOS – Flying an RPA without the remote pilot having a visual line of sight at all times. Instead, the remote pilot ﬂies the aircraft from a location remote from the aircraft and uses telemetry to determine the position of the aircraft and to command the aircraft. CASA approval must be obtained for all BVLOS operations.
Civil Aviation Act (CAA)	Civil Aviation Act 1988
Civil Aviation Regulations (CAR)	Civil Aviation Regulations 1988
Civil Aviation Safety Regulations (CASR)	Civil Aviation Safety Regulations 1998- the majority of rules pertaining to unmanned aircraft operations are contained within CASR Part 101.
CASA Licencing and Registration Centre (CLARC)	CLARC is the CASA section that deals with the issue of pilot licences including the remote pilot licence.
Controlled Airspace (CTA)	CTA is airspace of deﬁned dimensions within which an air traffic control service is provided to ﬂights. Controlled airspace surrounds all of the capital city main airports and larger regional airports as well as the military aerodromes.
Control Zone (CTR)	The CTR is that portion of controlled airspace in the immediate vicinity of a controlled airport where the controlled airspace extends from the ground upwards. The control zone has a deﬁned upper limit and usually has other controlled airspace immediately overhead.
Electronic Flight Bag (EFB)	An EFB is a software / hardware system which allows the storage of ﬂight information and access to operational information and brieﬁngs.
Enroute Supplement Australia (ERSA)	ERSA is a document which contains information about registered and certiﬁed aerodromes and helicopter landing sites in Australia. It is important to note that ERSA does NOT contain information about all aerodromes and helicopter landing sites.
Extended Visual Line of Sight (EVLOS)	EVLOS is a procedure whereby observers, located remotely from the pilot in command of an RPAS, are used to assist in keeping the aircraft in sight at all times during the operation and in providing separation from other manned and unmanned aircraft. The observers maintain communication with the pilot via radio or some other means throughout the operation. In theory, if sufficient observers with adequate communications systems could be deployed there would be no limit to the ﬂight distance achieved under EVLOS. In practice however, these operations are difficult to co-ordinate and need extensive communications networks and highly trained and skilled crew to be safely conducted.
Helicopter Landing Site (HLS)	A HLS is any area that is used for taking off or landing of helicopters. It is important to note that the majority of helicopter landing sites do NOT appear of any official aeronautical chart but many of the regularly used ones are depicted by electronic ﬂight bag mapping products. Most hospitals now have HLS associated with them.
Included RPA	An RPA operation that requires the pilot to hold a Remote Pilot Licence (or Unmanned Operator’s Certiﬁcate) and the operator to hold a Remote Operator’s Certiﬁcate (or Unmanned Operator’s Certiﬁcate). Included RPA include: all operations conducted outside of the Standard Operating Conditions (SOC); operations using aircraft with a maximum take-off weight if greater than 2 kg when operated over a third parties land; and operations using aircraft above 25 kg maximum take-off weight when operating over the pilot’s own land.
Excluded RPA	Unmanned aircraft which may, when operated in accordance with a constrained set of operating conditions known as the Standard Operating Conditions (SOC) may be operated for commercial purposes without the remote pilot needing to hold a Remote Pilot Licence or a Remote Operators Certiﬁcate. CASR 101.237 deﬁnes excluded RPA.
Hazardous operations	A person must not operate an unmanned aircraft in a way that creates a hazard to another aircraft, person or property. Refer to CASR 101.055.
Hire or reward	The term adopted by CASA to deﬁne commercial UAV/UAS/RPAS use. Any form of remuneration for ﬂying an unmanned aircraft in an aerial work operation (AWO), however small the AWO task, the reward or UAV; it constitutes ‘hire & reward’ and is therefore deﬁned as commercial. Refer to CASR101.270.
NOTAM	Notice to Airmen
Populous area	An area with a sufficient population density that if a fault in, or failure of, the unmanned aircraft (or rocket) poses an unreasonable risk to the life, safety or property of a person in the area who is not connected with the operation. Refer to CASR101.025.
Standard Operating Conditions (SOC)	The SOC are a set of operating conditions which, if fully complied with, allow certain classes of RPA (typically sub 2 kg aircraft) to be operated commercially without the piot in command holding a Remote Pilot Licence (RePL) or Remote Operator’s Certiﬁcate (ReOC). To comply with the SOC the: · RPA must be operated within visual line-of sight. · RPA must not be operated higher than 120 metres (400ft) AGL. · RPA must maintain at least 30 metres away from people who are not directly associated with the operation of the RPA (i.e. only the pilot and observer within 30 metres). · RPA must not be operated within 5.5km of the boundary of a controlled aerodrome. · RPA must not be ﬂown over any populous areas. These can include: beaches, parks and sporting ovals. · RPA must not be ﬂown over or near an area affecting public safety or where emergency operations are underway (without prior approval). · This could include situations such as a car crash, police operations, a ﬁre and associated ﬁreﬁghting efforts and search and rescue. · The operator may only ﬂy one RPA at a time.
Remotely Pilot Aircraft Operator’s Certiﬁcate (ReOC)	A ReOC is the operating certiﬁcate issued to the operator (rather than the pilot) of a remotely piloted aircraft. ReOC were previously known as an Unmanned Operator’s Certiﬁcate or UOC (This is like the airline licence for drone operators)
Remote Pilot License (RePL)	A RePL is the license required for by the pilot of a Remotely Piloted Aircraft System
Remotely Piloted Aircraft (RPA)	An RPA is an unmanned airborne platform which carries sensor/s and/or payload during ﬂight operations.
Remotely Piloted Aircraft System (RPAS)	The RPAS includes all of the pieces of equipment and resources used to to operate a remotely piloted aircraft. This includes the aircraft itself along with the ground control station, telemetry and communications systems, launch and landing equipment, sensors and other hardware and software used to operate the aircraft.
Unmanned Aircraft System (UAS)	This term is now generally replaced by “RPAS” or Remotely Piloted Aircraft System
Unmanned Aerial Vehicle (UAV)	This term is now generally replaced by “RPA” or Remotely Piloted Aircraft
Unmanned Operator’s Certiﬁcate (UOC)	This is a superseded term which has been replaced by ReOC
Visual line of sight (VLOS)	Keeping the unmanned aircraft in visual line of sight at all times unaided (except for prescription glasses or sunglasses) without the use of binoculars, telescopes or zoom lenses i.e. not ﬂying the into clouds or fog, behind trees, buildings or other (even partial) obstructions.

Aviation (like most industries) has a plethora of buzz words which are a source of constant intrigue to those outside of the industry. This page contains definitions of acronyms used in the Aviation Industry.

PDF Download can be found HERE.

Acronym	Definition
…T	Bearing (true)
A	Amber
A/A	Air to air
A/G	Air-to-ground
AAA	Amended meteorological message
AAAA	Aerial Application Association of Australia
AAC	Airworthiness Advisory Circular
AACC	Area approach control centre
AAD	Assigned altitude deviation
AAIM	Aircraft Autonomous Integrity Monitor
AAIS	Automatic aerodrome information service
AAL	Above aerodrome level
AAM	Advanced air mobility
AAR	Authorised Airworthiness Representative
AAR	Actual Arrival Report
AAT	Administrative Appeals Tribunal
ABAA	Amateur Built Aircraft Acceptance
ABAS	Aircraft Based Augmentation System
ABF	Australian Ballooning Federation
ABI	Airspace boundary information
ABI	Advance boundary information
ABM	Abeam
ABN	Aerodrome beacon
ABT	About
AC	Advisory Circular
ACA	Australian Commonwealth Authority
ACARS	Aircraft communication addressing and reporting system (pronounced ‘AY-CARS’)
ACAS	Airborne Collision Avoidance System
ACC	Area control centre
ACCID	Accident
ACD	Airways clearance delivery
ACFT	Aircraft
ACJ-XXX	Advisory Circular Joint (issued by the JAA, can be followed by a country code)
ACK	Acknowledge
ACL	Altimeter check location
ACMA	Australian Communications and Media Authority
ACN	Aircraft classification number
ACPT	Accept, accepted
ACROB	Acrobatics
AD	Airworthiness Directive
AD	Aerodrome
ADA	Advisory area
ADAO	Authorised Design Approval Organisation
ADC	Aerodrome chart
ADDGM	Aerodrome diagrams
ADDN	Addition, additional
ADF	Automatic Direction Finding (equipment)
ADF	Australian Defence Force
ADIZ	Air Defence Identification Zone
ADJ	Adjacent
ADO	Aerodrome office
ADQ	Adequate aerodrome
ADR	Advisory route
ADS	Automatic Dependent Surveillance
ADS-B	Automatic Dependent Surveillance – Broadcast
ADS-C	Automatic Dependent Surveillance – Contract
ADSU	Automatic Dependent Surveillance Unit
ADZ	Advise
AEP	Aerodrome emergency plan
AER	Authorised Engineering Representative
AERIS	Automatic en route information service
AFAF	Australian Future Airspace Framework
AFAP	Australian Federation of Air Pilots
AFCS	Automatic flight control system
AFIL	Air-Filed Flight Plan
AFIS	Aerodrome flight information service
AFM	Aircraft Flight Manual
AFRU	Aerodrome Frequency Response Unit (also known as a “beepback” unit)
AFS	Aeronautical fixed service
AFT	After
AFTN	Aeronautical fixed telecommunication network
AFZ	Australian fishing zone(s)
Ag	Agriculture
AGA	Again
AGD	Attorney-General’s Department
AGL	Above Ground Level
AH	Artificial Horizon
AI	Artificial intelligence
AIC	Aeronautical Information Circular
AIDC	Air traffic services inter-facility data communications
AIP	Aeronautical Information Publication
AIP ENR	Aeronautical Information Publication En-route
AIP ERSA	Aeronautical Information Publication En-route Supplement Australia
AIP Gen	Aeronautical Information Package (AIP) – General
AIP Gen	Aeronautical Information Package (AIP) – General
AIRAC	Aeronautical Information Regulation and Control
AIRC	Aeronautical Information and Control
AIREP	Air-Report
AIRMET	Airman’s Meteorological Information
AIS	Aeronautical Information Service
AL	Approach Lights
ALA	Aircraft Landing Area
ALA	Alighting area
ALA	Aircraft Landing Area
ALAEA	Australian Licensed Aircraft Engineers Association
ALARP	As Low as Reasonably Practical
ALERFA	Alert phase
ALI	Airworthiness Limitation Item
ALM	Aircraft Landing Minima
ALR	Alerting Message
ALRS or ALS	Approach lighting system
ALT	Altitude
ALTN	Alternate
ALTN	Alternating (light alternates in colour)
AMA	Area minimum altitude
AMC/GM	Acceptable Means of Compliance/Guidance Material
AMD	Amend, Amended
AMDT	Amendment (AIP amendment)
AME	Aircraft Maintenance Engineer
AMO	Approved Maintenance Organisation
AMP	Aircraft Maintenance Program
AMPA	Authorised Maintenance Personnel Assessor
AMRD	Australian Maintenance Requirements Document
AMS	Aircraft Maintenance Specialist
AMSA	Australian Maritime Safety Authority
AMSL	Above Mean Sea Level
AMSS	Aeronautical mobile satellite service
AMT	Aircraft Maintenance Technician
ANA	Air Navigation Act. Administered by Department of Infrastructure, Transport, Regional Development and Communications.
ANC	Aeronautical Chart 1:50,000 (followed by name/title)
ANCS	Aeronautical navigation chart – small scale (followed by name/title and scale)
ANO	Air Navigation Order
ANR	Air Navigation Regulations. Administered by Department of Infrastructure, Transport, Regional Development and Communications.
ANS	Answer
ANTA	Australian National Training Authority
ANVIS	Aviator Night Vision Imaging Systems
AO	Air Operator
AOC	Air Operator’s Certificate (AOC)
AOC	Aerodrome Obstacle Chart (followed by name/title)
AOCM	Air Operators Certification Manual
AOD	Alcohol and Other Drugs
AOPA	Aircraft Owners and Pilots Association
AP	Airport
APAPI	Abbreviated Precision Approach Path Indicator (pronounced ‘AY-PAPI’)
APCH	Approach
APDC	Aircraft Parking/Docking Chart (followed by name/title)
APF	Australian Parachute Federation
APMA	Australian Parts Manufacturer Approval
APN	Apron
APP	Approach Control
APRX	Approximate, Approximately
APSG	After Passing
APU	Auxillary power unit
APV	Approach with Vertical Guidance
AQZ	Area QNH Zone
ARC	Area Chart
ARFFS	Aerodrome Rescue and Fire Fighting Service (sometimes referred to as RFFS)
ARFL	Aeroplane Reference Field Length
ARFO	Area Forecast (now called Graphical area forecasts (GAF))
ARH	Aircraft Registration Holder
ARM	Airspace Risk Model
ARN	Aviation Reference Number – the number given to a pilot or engineer by CASA which appears on their licence.
ARNG	Arrange
ARO	Air traffic services reporting office
AROC	Aircraft radio operator certificate
AROCOP	Aircraft Radiotelephone Operator Certificate of Proficiencyv
ARP	Aerodrome reference point
ARP	Air-Report (message type designator)
ARQ	Automatic error correction
ARR	Arrive, Arrival
ARS	Special Air-Report (message type designator)
ARST	Arresting (specify (part of) aircraft arresting equipment)
AS	Australian Standard
ASA	Australian Skydiving Association
ASAC	Australian Sports Aviation Confederation
ASAP	As Soon as Possible
ASC	Ascend to or ascending
ASDA	Accelerate-stop distance available
ASE	Altimetry System Error
ASEPTA	Approved Single-engine Turbine Aeroplane
ASF	Aviation Safety Forum
ASH	Aviation Services Handbook
ASI	Aviation Safety Index
ASI	Air Speed Indicator
ASIR	Aviation Safety Incident Report
ASPH	Asphalt
ASR	Area Surveillance Radar
ASRA	Australian Sport Rotorcraft Association
ASSI	Air Safety Support International- a wholly-owned subsidiary of the UK Civil Aviation Authority
ASTM	American Society for Testing Materials
ASTRA	Australian Strategic Air Traffic Management Group
AT…	At (followed by time at which weather change is forecast to occur)
ATA	Actual Time of Arrival
ATA	Air Transport Association
ATA CSDD	Air Transport Association Common Support Data Dictionary
ATC	Air Traffic Control (in general)
ATD	Actual Time of Departure
ATEL/ANAV	Aeronautical Telecommunication and Radio Navigation Services
ATFM	Air Traffic Flow Management
ATIS	Automatic terminal information service
ATM	Air traffic management
ATN	Aeronautical Telecommunication network
ATP	At time or place
ATPL	Air Transport Pilot Licence
ATS	Air Traffic Service(s)
ATSB	Australian Transport Safety Bureau
ATSO	Australian Technical Standard Order
ATSOA	Australian Technical Standard Order Authorisation
ATTN	Attention
ATZ	Aerodrome traffic zone
AUF	Australian Ultralight Federation (now Recreational Aviation Australia)
AUTH	Authorised, Authorisation
AUW	All Up Weight
AUX	Auxiliary
AVBL	Available
AVG	Average
AVGAS	Aviation Gasoline
AVM	Abrupt Vertical Manoeuvres (by the MIL) (NOTAM or charts)
AWB	Airworthiness Bulletin
AWIB	Aerodrome Weather Information Broadcast
AWK	Aerial Work (Air work – general aviation)
AWO	Aerial work operation
AWS	Automatic Weather Station
AWTA	Advise as to what time is available
AWY	Airway
AZM	Azimuth
B	Blue
BA	Braking action
BAK	Basic aeronautical knowledge
BASA	Bilateral Aviation Safety Agreement
BASE	Cloud Base (met)
BCFG	Fog Patches (met)
BCN	Beacon (aeronautical ground light)
BCST	Broadcast
BDRY	Boundary
BECMG	Becoming
BFR	Before
BIP-M	Basic Instruction Package for Meteorologists
BIPMT	Basic Instruction Package for Meteorological Technicians
BKN	Broken (cloud descriptor) (met)
BL…	Blowing (followed by DU=dust, SA=sand or SN=snow)
BLDG	Building
BLO	Below Clouds
BLW	Below
BOM	Bureau of Meteorology
BOMB	Bombing
BR	Mist
BRG	Bearing
BRKG	Braking
BRW	Brakes release weight
BS	Broadcasting Station (Commercial)
BTL	Between Layers
BTN	Between
BVLOS	Beyond visual line of sight
C	Centre (Runway)
CA	Course Acquisition
CA Act	Civil Aviation Act (1988)
CA/GRO	Certified Air/Ground Radio Operator
CA/GRS	Certified Air/Ground Radio Service
CAA	The Civil Aviation Act 1988
CAA NZ	Civil Aviation Authority New Zealand
CAAP	Civil Aviation Advisory Publications
CAAP	Civil Aviation Advisory Publications
CAGRO	Certified Air Ground Radio Operation
CAMO	Continuing Airworthiness Management Organisation
CAMP	Continuous Airworthiness Maintenance Program
CAO	Civil Aviation Orders
CAO	Civil Aviation Orders
CAR	Civil Aviation Regulations (1988)
CAR	Civil Aviation Regulations (1988)
CAS	Calibrated air speed
CASA	Civil Aviation Safety Authority
CASR	Civil Aviation Safety Regulations (1998)
CASR	Civil Aviation Safety Regulations (1998)
CAT	Clear Air Turbulence
CAVOK	Cloud and Visibility OK
CB	Cumulonimbus (met)
CBT	Competency-based Training
CC	Cirrocumulus (met)
CCA	Corrected meteorological message (or CCB, CCC..etc. in sequence) (message type designator)
CCF	Capability Check Flight
CCTS	Circuits
CD	Candela
CDCCL	Critical Design Configuration Control Limit
CDI	Course Direction Indicator
CDL	Configuration Deviation List
CDN	Coordination (message type designator)
CEN	En Route and Area ATC unit
CEO	Chief Executive Officer
CET	Clearance Expiry Time
CF	Change Frequency to
CFI	Chief Flying Instructor (replaced by Head of Operations)
CFIT	Controlled Flight into Terrain
CFL	Cleared Flight Level
CFM	Confirm, I confirm
CFP	Current flight plan
CG	Centre of gravity
CGL	Circling guidance light(s)
CH	Channel continuity check
CHG	Modification (message type designator)
CHTR	Charter
CI	Cirrus (met)
CIDIN	Common ICAO data interchange network
CIR	Command Instrument Rating
CIT	Near, Over Large Town(s)
CIV	Civil
CK	Check
CL	Centre Line
CLA	Clear type of ice formation
CLBR	Calibration
CLD	Cloud (met)
CLG	Calling
CLIAS	Climbing Indicated Airspeed
CLMAX	Maximum Co-efficient of Lift
CLR	Clear, Cleared to… Clearance
CLSD	Closed, Close, Closing
CM (cm)	Centimetre
CMB	Climb to or Climbing to
CMPL	Configuration, Maintenance and Procedures
CMR	Certification Maintenance Requirements
CMSD	Commissioned
CNL	Flight plan cancellation message
CNS	Communication, Navigation and Surveillance
COA	Certificates of Approval (issued to maintenance organisations)
CofA	Certificate of Airworthiness
COM	Communication
CONC	Concrete
COND	Condition
CONS	Continuous
CONST	Construction, Constructed
CONT	Continue(s), Continued
COOR	Coordinate, Coordinated
COORD	Coordinates
COP	Change over point
CoR	Certificate of Registration
COS	Conical Surface
COT	At the Coast, Coastal
COV	Cover, Covered, Covering
CP	Chief pilot
CPDLC	Controller-Pilot Data Link Communication
CPL	Commercial Pilot Licence. Commercial pilots may fly for hire or reward (with some restrictions)
CRC	Cyclic redundancy check
CRIS	Cost Recovery Impact Statement
CRM	Crew Resource Management
CRZ	Cruise
CS	Call sign
CSDD	Common Support Data Dictionary
CSU	Constant Speed Unit
CTA	Control Area
CTAF	Common Traffic Advisory Frequency
CTAF(R)	Common Traffic Advisory Frequency – (Radio)
CTAM	Climb to and maintain
CTC	Category Technical Competency
CTC	Contact
CTL	Control
CTN	Caution
CTR	Control Zone
CU	Cumulus (met)
CUF	Cumuliform (met)
CUST	Customs
CVR	Cockpit voice recorder
CW	Carrier Wave
CWY	Clearway
D	Downward (tendency in RVR (Runway visual range) during previous 10 minutes)
D-ATIS	Data Link Automatic Terminal Information Service (pronounced’DEE-ATIS’)
D-VOLMET	Data Link VOLMET
D…	Danger Area (followed by identification)
DA	Decision Altitude
DA/H	Decision Altitude/Height
DAA	Detect and avoid
DALR	Dry Adiabatic Lapse Rate
DAME	Designated Aviation Medical Examiner
DAO	Designated Aviation Ophthamologist
DAP	Departure and Approach Procedures
DASA	Defence Aviation Safety Authority
DCD	Double channel duplex
DCKG	Docking
DCMSD	Decommissioned
DCPC	Direct Controller-Pilot Communication
DCS	Double channel simplex
DCT	Direct (in relation to flight plan clearances and type of approach)
DE	Form (used to precede the call sign of the calling station) (to be used in AFS as a procedure signal)
DEC	December
DEG	Degrees (Compass)
DEP	Depart, Departure, Departed, Departing, Departure Message
DER	Departure End of Runway
DER	Designated Engineering Representative
DES	Descend to, Descending to
DEST	Destination
DETRESFA	Distress Phase
DEV	Deviation, Deviating
DF	Direction Finder/ Finding
DFDR	Digital Flight Data Recorder
DFTI	Distance from touchdown indicator
DGA	Distance Measuring Equipment or Global Positioning Satellite System Arrival
DH	Decision Height
DIF	Diffuse
DISP	Displaced
DIST	Distance
DITRDC	Department of Infrastructure, Transport, Regional Development and
	Communications
DIV	Diversion, Divert, Diverting
DLA	Delay (message type designator)
DLIC	Data Link Initiation Capability
DLY	Daily
DME	Distance Measuring Equipment
DMEN	DME (International)
DMEP	DME (International Precision used in conjunction with Microwave Landing System)
DNG	Danger, Dangerous
DoD	Department of Defence
DOM	Domestic
DP	Dew Point Temperature
DPT	Depth
DR	Dead Reckoning (navigation)
DR…	Low drifting (followed by DU=dust, SA=sand or SN=snow)
DRG	During
DRMS	Drone rule management system
DS	Dust storm
DSB	Double sideband
DTAM	Descend to And Maintain
DTG	Date-Time Group
DTHR	Displaced Runway Threshold
DTRT	Deteriorate, Deteriorating
DTW	Dual tandem wheels
DU	Dust
DUC	Dense Upper Cloud (met)
DUPE	This is a duplicate message (to be used in Aeronautical Fixed Service as a procedure signal)
DUR	Duration
DVOR	Doppler VOR
DW	Dual wheels
DZ	Drizzle
E	East, East Longitude
E E E	Error (to be used in AFS as a procedure signal)
EASA	European Aviation Safety Agency
EAT	Expected Approach Time
EB	Eastbound
ECAR	European Civil Aviation Requirement (formerly JAR)
EDTO	Extended Diversion Time Operations
EET	Estimated Elapsed Time
EFB	Electronic Flight Bag
EFC	Expect further clearance
EGNOS	European Geostationary Navigation Overlay System
EGPWS	Enhanced Ground Proximity Warning System
EHF	Extremely high frequency (30,000 to 300,000 MHz)
EHR	Encumbrance Holder Register
ELBA	Emergency locator beacon-aircraft
ELEV	Elevation
ELR	Extra Long Range
ELT(S)	Emergency Locator Transmitter (Survival)
EM	Explanatory Memorandum (submitted to EXCO with regulation amendment)
EM	Emission
EMBD	Embedded in a Layer (to indicate cumulonimbus embedded in layers of other clouds)
EMERG	Emergency
EMS	Emergency Medical Service
EMS	Environment Management System
END	Stop-end (related to RVR)
ENDCE	Endurance
ENE	East North-East
ENG	Engine
ENR	En Route
ENRC	En Route Chart (followed by name/title)
EOBT	Estimated off Blocks Time
EPA	Environment Protection Agency
EPIRB	Electronic Position Indicating Radio Beacon (marine term.)
EQPT	Equipment
ER	Here..or herewith
ERC	En-route Chart
ERP	Emergency Response Plan
ERSA	En-route Supplement Australia
ES	Explanatory Statement (tabled with regulations in Parliament)
ESD	Electrostatic sensitive discharge
ESDE	ESD equipment
ESE	East Southeast
ESIR	Electronic safety incident report
EST	Estimate or estimated or estimate (message type designator)
ETA	Estimated Time of Arrival, Estimating Arrival
ETCM	Engine trend and condition monitoring
ETD	Estimated Time of Departure, Estimating Departure
ETO	Estimated Time Over significant point
ETOPS	Extended range operations by turbine-engined aeroplanes
ETP	Equi Time Interval
ETT	Estimated Time Interval
EV	Every
EVLOS	Extended visual line of sight
EVTOL	Electric vertical take-off and landing
EVU	Enforceable Voluntary Undertaking
EXC	Except
EXCO	Executive Council
EXER	Exercises, Exercising, to exercise
EXP	Expect, Expected, Expecting
EXTD	Extend, Extending, Extended
F	Fixed (chart symbol)
FAA	Federal Aviation Administration
FAA	Federal Aviation Administration of the USA
FAA TSO	Federal Aviation Administration (US) – Technical Standard Order
FAA TSO	Federal Aviation Administration (US) – Technical Standard Order
FAAOC	Foreign Aircraft Air Operator’s Certificate
FAC	Facility, Facilities
FADEC	Full Authority Digital Engine Control
FAF	Final Approach Fix
FAL	Facilitation of International Air
FAP	Final Approach Point
FARs	Federal Aviation Regulations (Federal Aviation Administration of the USA)
FATO	Final approach and take-off area
FAWP	Final Approach Waypoint
FAX	Facsimile Transmission
FBL	Light
FC	Funnel Cloud (tornado or water spout)
FCL	Flight Crew Licence/Licensing
FCST	Forecast
FCT	Friction coefficient
FD	Fault Detection
FDE	Fault detection and exclusion (in relation to GPS equipment)
FDL	Fixed Distance Lighting
FDPS	Flight Data Processing system
FDS	Flight Director System
FEL	Flight Engineer Licence
FEW	Few (cloud descriptor)
FFR	Flood, Fire Relief
FG	Fog
FIA	Flight Information Area
FIC	Flight Information Centre
FIMS	Flight information management system
FIO	Flight Information Office
FIR	Flight Information Region
FISA	Flight information service (automated)
FISS	Flight Information Service Station
FL	Flight Level
FLD	Field
FLG	Flashing
FLIR	Forward Looking Infra Red
FLR	Flares
FLT	Flight
FLTCK	Flight check
FLUC	Fluctuating, Fluctuation, Fluctuated
FLW	Follow(s), Following
FLY	Fly, Flying
FM	From
FM…	From (followed by time weather change is forecast to begin)
FMS	Flight Management System
FMU	Flow Management Unit
FNA	Final Approach
FNPT	Flight and Navigation Procedures Trainer
FOI	Flying Operations Inspector
FPD	Flight Plan Designator
FPL	Filed Flight Plan Message
FPM	Feet per Minute
FPR	Flight Plan Route
FPV	First person view
FR	Fuel Remaining
FREQ	Frequency
FRMS	Fatigue Risk Management System
FRNG	Firing (NOTAM)
FRONT	Front (relating to weather)
FRQ	Frequent
FS	Flight Service (in general)
FSA	Flight Safety Australia
FSL	Full Stop Landing
FSP	Fish Spotting
FSS	Flight service station
FST	First
FT	Feet
FTD	Flight training device
FTE	Full time equivalent
FTO	Flight Training Organisation
FU	Smoke
FXD	Fixed
FZ	Freezing
FZDZ	Freezing Drizzle
FZFG	Freezing Fog
FZL	Freezing Level
FZRA	Freezing Rain
G	Gravity
G/A	Ground-to-air
G/A/G	Ground-to-air and air-to-ground
GA	General Aviation
GA	Go ahead, resume sending (to be used in AFS as a procedure signal)
GAAP	General Aviation Aerodrome Procedures
GAMET	Area forecast for low-level flights
GAPAN	Honourable Company of Air Pilots, Australia, Inc.
GBAS	Ground Based Augmentation System
GCA	Ground Controlled Approach
GCN	General Computing Network (operated by Airservices Australia)
GDOP	Geometric Dilution of Precision
GEN	General
GEO	Geographic, true
GES	Ground Earth Station
GFA	The Gliding Federation of Australia
GFY	Glider Flying
GHA	Ground handling agents
GIVD	Gravity Induced Vestibular Dysfunction
GLD	Glider
GLOC	Gravity Induced Loss of Consciousness
GLONASS	Global Orbiting Navigation Satellite System (pronounced ‘GLO-NAS’)
GM	Guidance Material
GMC	Ground Movement Chart (followed by name/title)
GND	Ground
GNDCK	Ground Check
GNS	Global Navigation System
GNSS	Global navigation satellite system
GP	Guiding principles
GP	Glide Path
GP	FLG Group Flashing (number) (used in conjunction with aerodrome lighting)
GPI	Glide Path Intercept
GPS	Global positioning system (see GNSS)
GPWS	Ground proximity warning system
GR	Hail
GRAD	Minimum Required Climb Gradient
GRAS	Ground Based Regional Augmentation System
GRASS	Grass Landing Area
GRIB	Grid point values in binary form
GRVL	Gravel (NOTAM)
GS	Groundspeed
GS	Graupel (Small Hail and/or Snow Pellets – met)
GUND	Geoid Undulation
H24	Continuous day and night service
HAA	Helicopter Association of Australia
HAA	Height Above Aerodrome
HAAMC	Head of Aircraft Airworthiness and Maintenance Control
HALE	High-altitude long endurance
HAM	Head of Aircraft Maintenance
HAMC	Head of Aircraft Maintenance Control
HAPI	Helicopter approach path indicator
HAPs	High-altitude pseudo-satellites
HAT	Height Above Threshold
HBN	Hazard Beacon
HDF	High frequency direction-finding station
HDG	Heading
HDS	Hours of Daylight Saving (NOTAM)
HEL	Helicopter
HF	Human Factors
HF	High Frequency (3000 to 30,000 KHZ)
HFEM	Human Factor and Error Management System
HGFA	Hang Gliding Federation of Australia Inc
HGS	Heads-up Guidance System
HGT	Height, Height Above
HIAL	High Intensity Approach Lighting
HIOL	High Intensity Obstacle Lights
HIRL	High Intensity Runway Lighting
HJ	Sunrise to Sunset (NOTAM or ERSA)
HLDG	Holding
HLS	Helicopter Landing Site
HMI	Human-machine Interface
HN	Sunset to Sunrise (NOTAM or ERSA)
HO	Service available to meet operational requirements
HOFO	Head of Flying Operations
HOO	Head of Operations
HOSP	Hospital Aircraft
HOTAS	Head of Training and Standards
HOTC	Head of Training and Checking
HP	Horse Power
HPA	HectoPascal
HR	Hours
HS	Service available during hours of scheduled operations
HSL	Hold Short Lights
HUD	Head Up Display
HURCN	Hurricane
HVDF	High and very high frequency direction finding stations (at the same location)
HVY	Heavy (used to indicate the intensity of WX phenomena, eg HVY RA = heavy rain)
HX	No specific working hours (NOTAM or ERSA)
HYR	Higher
HZ	Haze
HZ (hz)	Hertz
HZS	Horizontal Surface
IA	Inspection authorisation
IAC	Instrument approach chart (followed by name/title)
IAF	Initial Approach Fix
IAL	Instrument Approach and Landing Chart
IAO	In and out of clouds
IAP	Instrument Approach Plate
IAR	Intersection of air routes
IAS	Indicated air speed
IATA	International Air Transport Association
IAW	In Accordance With
IAWP	Initial Approach Way-point
IBN	Identification Beacon
IC	Ice Crystals (MET code)
ICA	Instructions for continuing airworthiness (issued by manufacturer or designer)
ICAO	International Civil Aviation Organization
ICE	Icing, Ice
ICUS	In-command Under Supervision
ID	Identifier, identify
IDENT	Identification
IF	Instrument Flight
IF	Intermediate Approach Fix
IFF	Identification Friend/Foe
IFR	Instrument Flight Rules
IFSD	In-flight Shutdown
IG	Implementation Group
IGA	International general aviation
ILS	Instrument Landing System
IM	Inner Marker
IMC	Instrument meteorological conditions (other than VMC)
IMC	Indirect Maintenance Cost
IMI	Interrogation sign
IMPR	Improve, Improving, Improvement
IMT	Immediate, Immediately
INA	Initial approach
INBD	Inbound
INC	In Cloud
INCERFA	Uncertainty Phase
INFO	Information
INOP	Inoperative
INP	If not possible
INPR	In progress
INS	Inertial Navigation System
INSTL	Install, Installed, Installation
INSTR	Instrument
INT	Intersection
INTER	Intermittent, Intermittently (meteorological)
INTL	International
INTRG	Interrogator
INTRP	Interrupt, Interruption, Interrupted
INTSF	Intensify, Intensifying
INTST	Intensity
IoA	Instrument of appointment
IOC	Indirect Operating Cost
IPC	Illustrated Parts Catalogue
IREX	Instrument Training Examination
IRM	Immediately Reportable Matters
IRS	Internal Reporting System
ISA	International Standard Atmosphere
ISB	Independent Sideband
ISIM	Integrated Safety Investigation Methodology
ISO	International Organization for Standardization (e.g. ISO9000)
ISOL	Isolated
ITT	Interstage Turbine Temperature
IWI	Illuminated Wind Indicator
IWP	Intermediate Way-point
J-BAR	Jet Barrier
JAA	Joint Aviation Authorities (of Europe)
JAR	Joint Aviation Requirements (of the European JAA)
JAR-OPS	JAR Operations
JARUS	Joint Authorities for Rulemaking on Unmanned Systems
JTSO	Joint Technical Standard Order
JTST	Jet Stream
KDR	Knowledge Deficiency Report
KG (kg)	Kilograms
KHZ (kHz)	Kilohertz
KM (km)	Kilometers
KMH (km/h)	Kilometers per hour
KPA (kPa)	Kilopascals
KT (kt)	Knots
KW (kw)	Kilowatts
L	Left (runway identification)
L	Locator (see LM, LO)
LAAS	Local Area Augmentation System
LAHSO	Land and Hold Short Operations
LAME	Licensed Aircraft Maintenance Engineer
LAN	Inland
LAT	Latitude
LDA	Landing distance available
LDG	Landing
LDI	Landing Direction Indicator
LDP	Landing decision point
LEN	Length
LF	Low Frequency (30 to 300 KHZ)
LGT	Light, Lighting
LGTD	Lighted
LIH	Light Intensity High
LIL	Light Intensity Low
LIM	Light Intensity Medium
LIOL	Low Intensity Obstacle Lights
LIRL	Low Intensity Runway Lights
LJR	Low Jet Route
LL	Lower Limit
LLN	Low-level Navigation (by the MIL)
LLO	Low Level Operations (by the MIL)
LLZ	Localizer
LM	Locator (middle) see L and LO
LMT	Local mean time
LO	Locator (outer) see L and LM
LOC	Locally, Location, Located, Local
LOE	Lane of Entry
LONG	Longitude
LOSA	Line Operations Safety Audit
LPT	Liquid Penetrant Test
LRCS	Long-range communication system
LRG	Long Range
LRI	Line Replaceable Item
LRNS	Long-range navigation system
LSA	Light Sport Aircraft
LSd	CASA’s Legal Services Division
LTD	Limited
LUL	Lowest Usable Level
LV	Light and Variable (relating to wind)
LVE	Leave, Leaving
LVL	Level
LYR	Layer, Layered
M	Mach number (followed by figures ie .02 = Mach .02)
M (m)	Metres (preceded by figures)
M/E	Multi-engine
MAAT	Manual Authoring and Assessment Tool
MAE	Men and Equipment
MAG	Magnetic
MAHWP	Missed Approach Holding Way-point
MAINT	Maintenance
MAN	Manual
MAP	Aeronautical Maps and Charts
MAP	Manifold Air Pressure
MAPT	Missed Approach Point
MAR	At Sea
MAUW	Maximum All Up Weight
MAWP	Missed Approach Waypoint
MAX	Maximum
MBST	Microburst
MBZ	Mandatory Broadcast Zone
MCC	Multi-crew Co-ordination
MCM	Maintenance control manual
MCQFS	Manual of criteria for the qualification of flight simulators ICAO Doc 9625-AN/938
MCUR	Mean Cycles Between Unscheduled Removals
MCW	Modulated Continuous Wave
MDF	Medium Frequency Direction Finding Station
MDR	Major Defect Report
MEA	Minimum En-route Altitude
MED	Medical
MEL	Minimum equipment list
MERSITAB	Manufacturing, Engineering and Related Services Industry Training Advisory Body
MET	Meteorological, Meteorology
MET	REPORT Aviation routine weather report
METAR	Aviation routine weather report (in aeronautical meteorological code)
METRAD	MET Radar
MF	Medium Frequency (300 to 3000 KHZ)
MHZ (mhz)	Megahertz
MIFG	Shallow Fog
MIL	Military
MIL-STD	Military Standard
MIN	Minutes
MIOL	Medium Intensity Obstacle Lights
MIRL	Medium Intensity Runway Lights
MISC	Miscellaneous
MKR	Marker Radio Beacon
MLJ	Military Low Jet
MLJR	Military Low Jet Route
MLS	Microwave Landing System
MLW	Maximum Landing Weight
MM	Middle Marker
MMEL	Master minimum equipment list
MNM	Minimum
MNT	Monitor, Monitoring,
MNTN	Maintain, Maintained, Maintaining
MOA	Military Operating Area
MOC	Minimum obstacle clearance (required)
MOD	Moderate
MON	Above Mountains
MOPS	Minimum Operational Performance Standards
MOS	Manual of Standards
MOU	Memorandum of understanding
MOV	Move, Moved, Moving, Movement
MOWP	Method of Working Plan
MPD	Maintenance Planning Data
MPI	Magnetic Particle Inspection
MPL	Multi-crew Pilot Licence
MPS	Metres per Second
MPT	Magnetic Particle Inspection Technician
MRB	Maintenance Review Board
MRBR	Maintenance Review Board Report
MRG	Medium Range
MRO	Maintenance, repair and overhaul
MRP	ATS/MET Reporting Point
MS	Minus
MSA	Minimum sector altitude
MSAS	Multi-function Transport Satellite (MTSAT) Satellite-based Augmentation System
MSDS	Material Safety Data Sheets
MSG	Maintenance Steering Group
MSG-3	Maintenance Steering Group Logic Process
MSI	Maintenance Significant Item
MSL	Mean Sea Level
MSSR	Monopulse Secondary Surveillance Radar
MT	Mountain
MTBF	Mean Time Between Failure
MTBR	Mean Time Between Removals
MTP	Maximum Tyre Pressure
MTSAT	Multi-function Transport Satellite
MTTF	Mean Time To Failure
MTTR	Mean Time To Repair
MWO	Meteorological Watch Office
MX	Mixed type of ice formation (white and clear)
N	North, North Latitude
N1 or NG	Gas Generator Speed
N2	Second Stage Turbine Speed
NAA	National Airworthiness Authority (for a country other than Australia)
NAD	Non-acqueous Developer
NAIPS	National aeronautical information processing system
NANDTB	National Aerospace Non-destructive Testing Board
NANU	Notice Advisory to NavStar Users
NAP	Noise Abatement Procedures
NAS	National Airspace System
NASC	National AIS System Centre
NAT	NAVAID Training
NAV	Navigation
NAVAID	Navigation Aid
NAWD	Non-acqueous Wet Developer
NB	Northbound
NBFR	Not Before
NC	No Change
NDB	Non-directional Radio Beacon
NDDN	National Drone Detection Network
NDI	Non-destructive inspection
NDT	Non-destructive testing
NE	Northeast
NEAT	National Emerging Aviation Technologies
NEG	Negative, No. Permission not granted or, That is not correct
NFRM	Notice of Final Rule Making
NGT	Night
NIL	None
NM	Nautical Miles
NML	Normal
NNE	North North-East
NNW	North North-West
NOF	International NOTAM Office
NOSIG	No Significant Change
NOTAM	Notice To Airmen
NOZ	Normal Operating Zone
NP	Propeller Speed
NPA	Non-precision approach (procedures at aerodromes)
NPC	Notice of proposed change (consultation for amendment to a MOS)
NPRM	Notice of proposed rule making
NSC	Nil Significant Cloud
NTA	No TAF Amendment
NTL	National
NTS	Negative Torque Sensing System
NTSB	National Transportation Safety Board (of the USA)
NTZ	No-transgression zone
NVD	Night Vision Device
NVED	Night Vision Enhancement Devices
NVET	National vocational education and training
NVFR	Night Visual Flight Rules
NVG	Night Vision Goggles (by the MIL)
NVIS	Night Vision Imaging Systems
NW	North-West
NXT	Next
NZ CAA	New Zealand Civil Aviation Authority
NZS	New Zealand Standard
O/R	On Request
OAR	Office of Airspace Regulation
OAT	Outside Air Temperature
OBPR	Office of Best Practice Regulation
OBS	Omni Bearing Selector
OBS	Observe, Observed, Observation
OBSC	Obscure, Obscured, Obscuring
OBST	Obstacle
OBSTR	Obstruction
OC	Operating Certificate
OCA	Oceanic Control Area
OCA	Obstacle Clearing Altitude
OCC	Occulting (light)
OCH	Obstacle Clearance Height
OCNL	Occasional, Occasionally
OCTA	Outside Control Area
OCTR	Outside Control Zone
OEI	One Engine Inoperative
OEM	Original Equipment Manufacturer
OFZ	Obstacle Free Zone
OHD	Overhead
OHS	Occupation Health and Safety
OHSMS	Occupational Health and Safety Management Systems
OIS	Obstacle Identification Surface
OLC	Office of Legal Counsel
OLDI	On-line Data Interchange
OLS	Obstacle Limitation Surface
OM	Operations Manual
OM	Outer Marker
OPA	Opaque, white type of ice formation
OPC	Office of Parliamentary Counsel
OPMET	Operational Meteorological
OPN	Operational Notification Message (message type designator)
OPR	Operator, Operate, Operative, Operating, Operational
OPS	Operations
OSIP	Overhaul and Special Inspections Periods
OT	Other Times
OTAC	Overseas Territories Aviation Circulars
OTAR	Overseas Territories Aviation Requirements
OTLK	Outlook (used in Sigmet messages for volcanic ash and tropical cyclones)
OTP	On Top
OUBD	Outboard
OVC	Overcast
OW	Over Water
P..	Prohibited Area (followed by identification)
PA	Precision Approach
PAL	Pilot Activated Lighting
PANS	Procedures for Air Navigation Services
PANS-OPS	Procedures for Air Navigation Services – Aircraft Operations ICAO Doc 8168 Vol I and II
PAPI	Precision Approach Path Indicator
PAR	Precision Approach Radar
PARL	Parallel
PATC	Precision Approach Terrain Chart (followed by name/title)
PAX	Passengers
PBM	Power Plant Build-Up Manual
PC	Personal Computer
PCD	Proceed, Proceeding
PCL	Pilot Controlled Lighting
PCN	Pavement classification number
PCT	Practical consolidation training
PDC	Pre-Departure Clearance
PDO	Product distribution organisation
PDOP	Positional Dilution of Precision
PDSE	Pre-departure Service Check
PEC	Pressure Error Correction
PERM	Permanent
PFC	Porous Friction Course
PFR	Preferred Route
PIB	Pre-flight information bulletin
PIC	Pilot-in-command
PICUS	Pilot-in-Command Under Supervision
PIFR	Private IFR rating
PILS	Practice ILS
PIREP	Pilot Reports
PJE	Parachute Jumping Exercise
PLN	Flight Plan
PLVL	Present Level
PMP	Primary Maintenance Process
PN	Prior Notice Required
PO	Dust Devils
POB	Persons on Board
POH	Pilot Operating Handbook
POSS	Possible
PPI	Plan Position Indicator
PPL	Private Pilot Licence
PPR	Prior Permission Required
PPS	Precise Positioning Service
PPSN	Present Position
PRD	Prohibited, Restricted and Danger Areas
PRFG	Aerodrome Partially Covered by Fog (MET code)
PRI	Primary
PRKG	Parking
PRM	Precision runway monitoring
PROB	Probable, Probability
PROC	Procedure
PROV	Provisional
PS	Plus
PSG	Passing
PSN	Position
PSP	Pierced Steel Plank
PSR	Primary Surveillance Radar
PSYS	Pressure System(s)
PTBL	Portable
PTN	Procedure Turn
PTT	Push To Talk
PVT	Private
PWR	Power
QDM	Magnetic Heading (zero wind)
QDR	Magnetic Bearing
QEC	Quick Engine Change Unit
QFE	An altimeter set to QFE will read zero when the aircraft is on the runway
QNH	Altimeter subscale setting to obtain elevation or altitude
QTE	True Bearing
QTG	Qualification test guide
QUAD	Quadrant
R	Right (runway system identification)
R….	Restricted Area (followed by number)
R/T or RTF	Radio Telephone
RA	Rain
RA-Aus or RAAus	Recreational Aviation Australia
RAAA	Recreational Aviation Association of Australia
RAAO	Recreational Aviation Administrative Organisation
RAC	Rules of the Air and Air Traffic Services
RAD	Radius
RAeS	Royal Aeronautical Society
RAFC	Regional Area Forecast Centre
RAG	Runway Arresting Gear
RAI	Runway Alignment Indicator
RAIM	Receiver Autonomous Integrity Monitoring
RAM	Regional air mobility
RAM	Repair and Maintenance
RAPIC	Radar Picture (MET)
RAS	Radar Advisory Service
RASF	Regional Aviation Safety Forum
RAT	RAM Air Turbine
RCA	Request For Corrective Action
RCA	Reach Cruising Altitude
RCC	Rescue Coordination Centre
RCH	Reach, Reaching
RCL	Runway Centre Line
RCLL	Runway Centre Line Lights
RCLM	Runway Centre Line Marking
RDL	Radial
RDO	Radio
RDS	Runway Distance Supplement
RE…	Recent (used to qualify weather phenomena, eg RERA = recent rain)
REC	Receive, Receiver, Received
REDL	Runway Edge Lights
REF	Reference to… Refer to…
REG	Registration
RENL	Runway End Lights
ReOC	PRPA operator’s certificate
REP	Report, Reported, Reporting, Reporting Point
RePL	Remote pilot licence
REQ	Request, Requested
RERTE	Re-route
RES	Reserve Fuel
RESA	Runway end safety area
RESTR	Restrictions
REV	Review
RF	Radio frequency
RFACA	Royal Federation of Aero Clubs of Australia
RFC	Regional Forecasting Centre (Met)
RFFS	Rescue and Fire Fighting Services
RH	Radio Height
RHC	Right-hand Circuit
RIF	Reclearance in Flight
RIFTO	Restricted Instrument Flight Take-off
RIS	Radar information service
RL	Report Leaving
RLA	Relay to
RLLS	Runway Lead-in Lighting
RMIT	Royal Melbourne Institute of Technology
RMK	Remark(s)
RMS	Root Mean Square
RNAV	Area navigation
RNP	Required navigation performance
RO	Registered operator
ROBEX	Regional OPMET Bulletin Exchanges
ROC	Rate of Climb
ROD	Rate of Descent
ROFOR	Route Forecast (in aeronautical meteorological code)
RPA	Remotely piloted aircraft
RPA	Rules and practices for aerodromes
RPAS	Remotely Piloted Aircraft Systems
RPI	Runway Point of Intercept
RPI	Radar Position Indicator
RPI	Regulatory Performance Indicator
RPL	Recreational Pilot Licence
RPM	Revolutions Per Minute
RPS	Remote pilot station
RPT	Regular Public Transport
RQ	Require(d)
RQMNTS	Requirements
RR	Report Reaching
RRM	Routine Reportable Matters
RSC	Rescue Sub-Centre
RSCD	Runway Surface Condition
RSP	Responder Beacon
RSR	En route Surveillance Radar
RTB	Return to Base
RTCA	Radio Technical Commission for Aeronautics
RTE	Route
RTHL	Runway Threshold Light(s)
RTIL	Runway Threshold Identification Lights
RTN	Return, Returned, Returning
RTO	Registered training organisation
RTO	Rejected take-off
RTS	Return to Service
RTZL	Runway Touchdown Zone Light(s)
RVR	Runway visual range
RVSM	Reduced Vertical Separation Minimum
RWS	Runway Strip
RWY	Runway
S	South, South Latitude
S-I	Straight-In
S/E	Single-engine
SA	Situation Awareness
SA	Sand
SA	Special Authorisation
SAAA	Sport Aircraft Association of Australia
SAF	Sustainable Aviation Fuels
SAIL	Specific assurance and integrity levels
SAL	Supplementary Airline Licence
SALR	Saturated Adiabatic Lapse Rate
SALS	Simple Approach Lighting System
SAR	Search and Rescue
SARPs	Standards and Recommended Practices
SARTIME	Time search action required
SARWATCH	Search and Rescue Watch
SATCOM	Satellite Communication
SB	Southbound
SB	Service Bulletin
SBAS	Satellite Based Augmentation System
SC	Stratocumulus
SCC	Standards Consultative Committee
SCP	Safety Critical Personnel
SCT	Scattered (meteorological)
SDBY	Standby
SDC	Standard Departure Clearance
SDR	Service difficulty report
SE	South East
SEA	Sea (used in connection with sea-surface temperature and state of the sea)
SEACO	Single engine aircraft only
SEC	Seconds
SECN	Section
SECT	Sector
SELCAL	Selective Calling System
SER	Service, Servicing, Served
SEV	Severe (used eg to qualify icing and turbulence report)
SFC	Surface
SFL	Sequenced Flashing Lights
SG	Snow Grains
SH…	Showers
SHF	Super High Frequency (3,000 to 30,000 MHZ)
SHP	Shaft Horse Power
SID	Standard instrument departure
SIF	Selective Identification
SIG	Significant
SIGMET	Information concerning en route weather phenomena which may affect the safety of aircraft operations
SIL	Service Information Letter
SIMUL	Simultaneous, or Simultaneously
SKC	Sky Clear
SKED	Schedule, Scheduled
SL	Service Letter
SLP	Speed Limiting Point
SLW	Slow, Slowly
SM	Safety Manager
SMC	Surface Movement Control
SMR	Surface Movement Radar
SMS	Safety management system
SN	Snow
SNOWTAM	A special series NOTAM announcing hazardous conditions or removal related to snow, ice, slush, or standing water on the movement area.
SOC	Start of Climb
SOE	Schedule of experience
SOM (soM)	System of Maintenance
SOPs	Standard Operating Procedures
SOR	Summary of responses
SORA	Specific operations risk assessment
SOT	Start of TORA (take-off)
SP	Single Pilot
SPA	Sport Aviation
SPECI	Aviation Special Weather (in aeronautical meteorological code)
SPFIB	Specific Preflight Information Bulletin
SPOT	Spotwind
SPS	Standard Positioning Service
SQ	Squall
SR	Sunrise
SRB	Safety Review Board
SRD	Standard Radar Departure
SRG	Short Range
SRM	Structural Repair Manual
SRR	Search and Rescue Region
SS	Sandstorm
SS	Sunset
SSA	System safety assessment
SSB	Single Sideband
SSCRO	Senate Standing Committee on Regulations and Ordinances
SSE	South South-East
SSI	Structural Significant Item
SSM	System Schematics Manual
SSW	South South-West
ST	Stratus
STA	Straight in Approach
STAR	Standard instrumental arrival
STAR	Standard Arrival Route
STARs	Standard terminal arrival routes
STC	Supplemental Type Certificate
STD	Synthetic training device
STD	Standard
STF	Stratiform
STN	Station
STNR	Stationary
STODA	Supplementary Take-off Distance
STOL	Short Take-off and Landing
STS	Status
STWL	Stopway Light(s)
SUBJ	Subject to
SUP	Supplement (AIP Supplement)
SUPPS	Regional Supplementary Procedures
SVCBL	Serviceable
SVY	Survey Operations
SW	South-West
SWS	Soft Wet Surface
SWY	Stopway
T	Temperature
TA	Traffic advisory
TA	Transition Altitude
TAAATS	The Australian Advanced Air Traffic System
TAAM	Airservices Australia’s Total Airspace Airport and Aerodrome Modeller
TAC	Terminal Area Chart
TACAN	Tactical Air Navigation Aid
TAF	Terminal Area Forecast; Aerodrome Forecast
TAIL	Tailwind
TAR	Terminal Area Surveillance Area
TAS	True Airspeed
TAT	Terminal Area Thunderstorm Service (meteorological term)
TAWS	Terrain awareness and warning system
TAWS-B+ System	Terrain awareness and warning system
TAX	Taxiing, Taxi
TBA	To be advised
TBO	Time Between Overhauls
TC	Type Certificate
TCAC	Tropical Cyclone Advisory Centre
TCAS	Traffic alert and collision avoidance system
TCDS	Type certificate data sheet
TCH	Threshold Crossing Height
TCO	Training and Checking Organisation
TCTA	Trans-continental Control Area
TCU	Towering Cumulus (met)
TDO	Tornado
TDZ	Touchdown Zone
TECR	Technical Reason
TEL	Telephone
TEM	Tool And Equipment Manual (Illustrated)
TEM	Threat and Error Management
TERPs	Terminal and En-route procedures
TFC	Traffic
TFR	Terrain Following Radar (by the MIL)
TGL	Touch & Go Landing
TGS	Taxiing Guidance System
THR	Threshold
THRU	Through
TIBA	Traffic Information Broadcasts by Aircraft
TIL	Until
TIP	Until Past (place)
TIS	Time in service
TKOF	Take-off
TLOF	Touchdown and lift-off area
TLS	Transponder Landing System
TLW	Time Limited WIP (work in progress)
TMA	Terminal Control Area
TMG	Track Made Good
TNA	Training Needs Analysis
TNA	Turn Altitude
TNH	Turn Height
TNS	Transitional Surface
TOC	Top of Climb
TODA	Take-off distance available
TOP	Cloud Top
TORA	Take-off run available
TOT	Turbine Outlet Temperature
TP	Turning Point
TR	Track
TRA	Temporary Reserved Airspace
TRAN	Transition
TRANS	Transmits, Transmitter
Transport Canada	Transport Canada
TRL	Transition Level
TROP	Tropopause
TS…	Thunderstorm
TSI	Time Since Installation
TSO	Technical Standard Order
TTF	Trend Type Forecast
TURB	Turbulence
TWG	Technical working group
TWR	Aerodrome Control Tower, Aerodrome Control
TWY	Taxiway
TWYL	Taxiway Link
TYP	Type of Aircraft
TYPH	Typhoon
U/S	Unserviceable
UAB	Until Advised By
UAM	Urban air mobility
UAS	Unmanned aerial system (UAV/RPAS)
UAV	Unmanned aerial vehicles
UDF	UHF Direction Finding Stations
UFIT	Uncontrolled Flight Into Terrain
UFN	Until Further Notice
UHDT	Unable Higher Due Traffic
UHF	Ultra High Frequency (300 to 3,000 MHZ)
UIR	Upper Flight Information Region
UL	Upper Limits
UNA	Unable
UNAP	Unable to Approve
UNICOM	Universal Communication
UNL	Unlimited
UNLC	Unlicensed
UNREL	Unreliable
UOC	Unmanned operating certificate
US FAR	Federal Aviation Regulations (of the USA)
UTA	Upper Control Area
UTC	Coordinated Universal Time
UTM	Uncrewed Aircraft Systems Traffic Management
V	Velocity
V1	Take-off Decision Speed
V2	Take-off Safety Speed (Applicable to Larger Multi-engine Aircraft)
VA	Maximum Manoeuvring Speed
VA	Volcanic Ash
VAA-H	Visual Approach Area – Helicopter
VAAC	Volcanic Ash Advisory Centre
VAC	Visual Approach Chart (followed by name/title)
VAL	In Valleys
VAR	Magnetic Variation
VASIS	Visual Approach Slope Indicator System
VC	Vicinity of the aerodrome
VCY	Vicinity
VDF	VHF Direction Finding Station
VEC	Visual En-route Chart
VER	Vertical
VFE	Flap Extension Speed
VFR	Visual flight rules
VHF	Very High Frequency (30 to 300 MHZ)
VHFCOM	Very High Frequency Communication
VIA	By way of…
VIMD	Maximum Drag Speed
VIP	Very Important Person
VIS	Visibility
VLE	Maximum Speed with Landing Gear Extended
VLF	Very Low Frequency (3 to 30 KHZ)
VLJ	Very Light Jet
VLO	Landing Gear Operating
VLO2	Landing Gear Operation Down
VLOS	Visual line of sight
VLR	Very Long Range
VMAN	Velocity Manoeuvre Speed
VMC	Minimum Control Speed
VMC	Visual Meteorological Conditions
VMCA	Minimum Control Airspeed Airborne (Red line speed)
VMCG	Minimum Control Airspeed on the Ground
VMO	Maximum Structural Cruising Speed
VNAV	Vertical Navigation
VNE	Never Exceed Speed
VNO	Normal Operating Speed
VOLMET	Meteorological Information for Aircraft in Flight
VOR	VHF Omni-directional Radio Range (OMNI)
VP	Variable Pitch Propellers
VR	The speed at which the aircraft is rotated to lift off from the runway
VRB	Variable
VSI	Vertical Speed Indicator
VSI	Clean Stall Speed
VSL	Vertical speed limit
VSO	Stalling speed, minimum steady flight speed in the landing configuration
VSO	Stall speed with undercarriage and flap selected
VSSE	Safe single-engine Speed
VTC	Visual Terminal Chart
VTOL	Vertical take-off and landing
VTOSS	Take-off Safely Speed
VX	Best Angle of Climb Speed
VXSE	Best Single-engine Angle of Climb Speed
Vy	Best Rate of Climb Speed
VYSE	Best Single-engine Rate of Climb Speed (Blue line speed)
W	West, West Longitude
W/V	Wind Velocity
WAAS	Wide Area Augmentation System
WAC	World Aeronautical Chart ICAO 1:1,000,000 (followed by name/title)
WAFC	World Area Forecast Centre
WAFS	World Area Forecast System
WATIR	Weather and Terminal Information Reciter
WB	Westbound
WBM	Weight And Balance Manual
WDI	Wind Direction Indicator
WED	Wednesday
WEF	With Effect From, Effective From
WGS-84	World Geodetic System 1984
WI	Within
WID	Width
WIE	With Immediate Effect, Effective Immediately
WILCO	Will Comply
WIND	Wind
WIP	Work in Progress
WKN	Weaken, Weakening
WM	Wiring Manual
WMO	World Meteorological Organisation
WO	Without
WPT	Way-point
WRNG	Warning
WS	Wind Shear
WSW	West South-West
WT	Weight
WTSPT	Water Spout
WX	Weather
X	Cross runway
XBAR	Crossbar (of approach lighting system)
XNG	Crossing
XS	Atmospherics
XSEC	Extra Section
Y	Yellow
YR	Your/s
Z	Coordinated Universal Time (in meteorological messages)

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NOTAM Decoding

Aviation Weather Decode Card

Aviation Definitions

Aviation Abbreviations