|
Contraction
|
Definition
|
Usage
|
|
M
|
in RVR indicates
visibility less than lowest reportable sensor value (e.g. M600)
|
METAR
|
|
M
|
in temperature field means “minus” or below zero
|
METAR
|
|
M
|
Mach number
|
GEN
|
|
M
|
maritime (air mass)
|
NWS
|
|
M
|
metres (preceded by figures)
|
ICAO
|
|
M
|
missing (weather
reports only)
|
NWS
|
|
M
|
Mountain Standard Time
(time groups only)
|
NWS
|
|
MA
|
map analysis
|
NWS
|
|
MAA
|
maximum authorized
(IFR) altitude
|
GEN
|
|
MAC
|
Military Airlift
Command
|
GEN
|
|
MACH
|
MACH Number (speed
ratio to speed of sound)
|
ATC
|
|
MACKAY
|
Mackay Radio and
Telegraph Company
|
GEN
|
|
MACVFR
|
make altitude changes
VFR
|
ATC
|
|
MAFAP
|
minimum altitude over
facility on final approach course
|
ATC
|
|
MAG
|
magnetic
|
GEN
|
|
MAGSI
|
minimum altitude at
glide slope intersection inbound
|
GEN
|
|
MAINT
|
maintenance
|
ICAO
|
|
MAL
|
maintain at least
(altitude)
|
ATC
|
|
MALS
|
medium intensity
approach lighting system
|
GEN
|
|
MALSF
|
medium intensity
approach lighting system with sequenced flashers
|
GEN
|
|
MALSR
|
medium intensity
approach lighting system with runway alignment indicator lights
|
GEN
|
|
MAM
|
maintenance assumes
monitor
|
GEN
|
|
MAN
|
Manitoba
|
NWS
|
|
MAN
|
manual
|
GEN
|
|
MANAM
|
manual amendment
|
GEN
|
|
MANOP
|
manual of operations
|
GEN
|
|
MAP
|
aeronautical maps and
charts
|
ICAO
|
|
MAP
|
missed approach point
|
GEN
|
|
MAPS
|
Meteorological
Aeronautical Presentation System
|
GEN
|
|
MAPT
|
missed approach point
|
ICAO
|
|
MAR
|
at sea
|
ICAO
|
|
MARPT
|
municipal airport
|
GEN
|
|
MARSA
|
military assumes responsibility
for separation of aircraft
|
GEN
|
|
MAS
|
manual A1 simplex
|
ICAO
|
|
MAS
|
military alert system
|
GEN
|
|
MAX
|
maximum
|
GEN
|
|
MB
|
marker beacon
|
GEN
|
|
MB
|
millibars
|
GEN
|
|
MCA
|
minimum crossing
altitude
|
ICAO
|
|
MCAS
|
Marine Corps Air
Station
|
GEN
|
|
MCAS(H)
|
Marine Corps Air
Station (Helicopter)
|
GEN
|
|
MCK
|
maintenance check
|
GEN
|
|
MCS
|
Master Control Station
|
ATC
|
|
MCW
|
modulated continuous
wave
|
ICAO
|
|
MCZNE
|
minimum when control
zone effective
|
GEN
|
|
MDA
|
minimum descent
altitude
|
ICAO
|
|
MDF
|
medium frequency
direction finding station
|
ICAO
|
|
MDFR
|
make descent from
|
ATC
|
|
MDFY
|
modify
|
GEN
|
|
MDH
|
minimum descent height
|
ICAO
|
|
MDT
|
moderate
|
GEN
|
|
MDZ
|
modernize
|
GEN
|
|
MDZN
|
modernization
|
GEN
|
|
MEA
|
minimum en route
altitude
|
ICAO
|
|
MECH
|
mechanic
|
GEN
|
|
MED
|
medical
|
GEN
|
|
MED
|
medium
|
GEN
|
|
MEDEVAC
|
medical emergency
evacuation
|
ICAO
|
|
MEGG
|
merging
|
NWS
|
|
MEHT
|
minimum eye height over
threshold
|
ICAO
|
|
MEML
|
memorial
|
GEN
|
|
MET
|
meteorological
|
GEN
|
|
METAR
|
aviation routine
weather report
|
ICAO
|
|
METOF
|
meteorological officer
|
GEN
|
|
METRO
|
metropolitan
|
GEN
|
|
MEX
|
Mexico
|
NWS
|
|
MF
|
medium frequency
|
GEN
|
|
MFL
|
maintain flight level
|
ATC
|
|
MFOB
|
minimum fuel on board
|
ATC
|
|
MFPOF
|
master flight plan on
file
|
ATC
|
|
MFS
|
military flight service
|
GEN
|
|
MFV
|
forward visibility more
than (miles)
|
ATC
|
|
MFXT
|
meter fix time
|
ATC
|
|
MGAT
|
make good a track of
(degrees)
|
ATC
|
|
MGMT
|
make good a magnetic
track of (degrees)
|
ATC
|
|
MGMT
|
management
|
GEN
|
|
MGR
|
manager
|
GEN
|
|
MHA
|
minimum holding
altitude
|
GEN
|
|
MHDF
|
medium and high
frequency directionfinding station (same
location)
|
ICAO
|
|
MHDG
|
magnetic heading
|
GEN
|
|
MHFR
|
military height finder
radar
|
GEN
|
|
MHKVLY
|
Mohawk Valley
|
NWS
|
|
MHVDF
|
medium high and very
high frequency directionfinding station
(same location)
|
ICAO
|
|
MHz
|
megahertz
|
GEN
|
|
MI
|
manufacturing inspector
|
GEN
|
|
MI
|
mile
|
GEN
|
|
MI
|
shallow
|
METAR
|
|
MID
|
middle
|
GEN
|
|
MID
|
midpoint (related to
RVR)
|
ICAO
|
|
MID/ASIA
|
ICAO Middle East/Asia
Region
|
ATC
|
|
MIDIZ
|
MidCanada Identification Zone
|
GEN
|
|
MIDN
|
midnight
|
NWS
|
|
MIDPT
|
midpoint
|
GEN
|
|
MIFG
|
patches of shallow fog
not deeper than two meters
|
NWS
|
|
MIFG
|
shallow fog
|
METAR
|
|
MIJI
|
meaconing, intrusion, jamming, interference
|
ATC
|
|
MIL
|
military
|
ICAO
|
|
MIMNO
|
mimeographic notice
|
GEN
|
|
MIN
|
minute
|
ICAO
|
|
MINIT
|
minutes in trail
|
ATC
|
|
MIREQ
|
minimum requirements
specified
|
GEN
|
|
MIRL
|
medium intensity runway
edge lights
|
GEN
|
|
MIS
|
Missing …(transmission
identification)
|
ICAO
|
|
MISC
|
miscellaneous
|
GEN
|
|
MISG
|
missing
|
GEN
|
|
MISL
|
missile
|
GEN
|
|
MIT
|
miles in trail
|
ATC
|
|
MITO
|
minimum interval takeoff
|
ATC
|
|
MKCT
|
make check turn
|
ATC
|
|
MKD
|
marked
|
GEN
|
|
MKR
|
marker
|
GEN
|
|
MKR
|
marker radio beacon
|
ICAO
|
|
MLS
|
microwave landing
system
|
GEN
|
|
MLTLVL
|
melting level
|
NWS
|
|
MM
|
middle marker
|
ICAO
|
|
MM
|
millimeter
|
GEN
|
|
MMACH
|
maintain Mach
|
ATC
|
|
MMO
|
main meteorological
office
|
NWS
|
|
MNLD
|
mainland
|
NWS
|
|
MNLY
|
mainly
|
GEN
|
|
MNM
|
minimum
|
ICAO
|
|
MNPS
|
minimum navigation
performance specification
|
ATC
|
|
MNPSA
|
minimum navigation
performance specification airspace
|
ATC
|
|
MNT
|
monitor
|
ICAO
|
|
MNTN
|
maintain
|
ICAO
|
|
MNVR
|
maneuver
|
GEN
|
|
MOA
|
memorandum of agreement
|
GEN
|
|
MOA
|
military operations
area
|
ICAO
|
|
MOC
|
minimum obstacle
clearance (required)
|
ICAO
|
|
MOCA
|
minimum obstruction
clearance altitude
|
ICAO
|
|
MOD
|
moderate
|
GEN
|
|
MOD
|
modulate or modulation
or modulator
|
GEN
|
|
MOGR
|
moderate or greater
|
NWS
|
|
MON
|
above mountains
|
ICAO
|
|
MON
|
Monday
|
ICAO
|
|
MONOK
|
monitor resumed normal
operation
|
GEN
|
|
MONOS
|
monitor out of service
|
GEN
|
|
MONTR
|
monitor
|
NWS
|
|
MOPS
|
Minimum operational
performance standards
|
ICAO
|
|
MOPTAR
|
multiobject phase tracking and ranging
|
GEN
|
|
MOREPS
|
monitor station reports
|
GEN
|
|
MOT
|
Ministry of Transport
(Canada)
|
GEN
|
|
MOTNE
|
Meteorological
Operational Telecommunications Network Europe
|
ICAO
|
|
MOV
|
move
|
NWS
|
|
MPH
|
miles per hour
|
GEN
|
|
MPP
|
Merit Promotion Program
|
GEN
|
|
MPS
|
meters per second
|
ICAO
|
|
MPVA
|
maintain a position VFR
and advise
|
ATC
|
|
MRA
|
minimum reception
altitude
|
GEN
|
|
MRG
|
medium range
|
GEN
|
|
MRGL
|
marginal
|
NWS
|
|
MRM
|
maintenance returns
monitor
|
GEN
|
|
MRNG
|
morning
|
NWS
|
|
MRP
|
ATS/MET reporting point
|
ICAO
|
|
MRR
|
mechanical reliability
report
|
GEN
|
|
MRTM
|
maritime
|
NWS
|
|
MRU
|
Military Radar Unit
|
GEN
|
|
MS
|
minus
|
NWS
|
|
MSA
|
minimum safe/sector
altitude
|
GEN
|
|
MSAW
|
minimum safe altitude
warning
|
GEN
|
|
MSG
|
message
|
ICAO
|
|
MSGCTR
|
message center
|
GEN
|
|
MSL
|
mean sea level
|
ICAO
|
|
MSR
|
Message …(transmission identification)
has been misrouted
|
ICAO
|
|
MSSR
|
Monopulse secondary surveillance radar
|
ICAO
|
|
MSTLY
|
mostly
|
NWS
|
|
MSTR
|
moisture
|
NWS
|
|
MT
|
mountain
|
ICAO
|
|
MTCA
|
minimum terrain
clearance altitude
|
GEN
|
|
MTI
|
moving target indicator
|
ATC
|
|
MTN
|
mountain
|
NWS
|
|
MTR
|
military training route
|
GEN
|
|
MTRL
|
material
|
GEN
|
|
MTRY
|
momentary
|
GEN
|
|
MTU
|
metric units
|
ICAO
|
|
MTW
|
mountain wave
|
ICAO
|
|
MU
|
designate a friction value
representing runway surface conditions (Greek letter)
|
GEN
|
|
MUA
|
maximum usable altitude
|
GEN
|
|
MUF
|
maximum usable
frequency
|
GEN
|
|
MULT
|
multiple
|
GEN
|
|
MUNI
|
municipal
|
GEN
|
|
MV
|
millivolt
|
GEN
|
|
MVA
|
minimum vector altitude
|
GEN
|
|
MVDF
|
medium and very high
frequency directionfinding station (same
location)
|
ICAO
|
|
MVFR
|
maintain VFR
|
ATC
|
|
MVFR
|
marginal VFR
|
NWS
|
|
MVSP
|
maintain visual
separation
|
ATC
|
|
MWO
|
Meteorological Watch
Office
|
ICAO
|
|
MWRC
|
maintain well to right
of course
|
ATC
|
|
MWTCS
|
modernized weather
teletypewriter communications system
|
GEN
|
|
MXD
|
mixed
|
NWS
|