U.S. DEPARTMENT OF TRANSPORTATION
FEDERAL AVIATION ADMINISTRATION
Air Traffic Organization Policy

ORDER
JO 7340.2D
Effective Date:
April 3, 2014
 
     

Subject:  Contractions
       Includes: Change 1 effective 8/22/13, Change 2 effective 12/12/13, and Change 3 effective
       4/3/14
 
 

[Back to Section 1. Decode]

M

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

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

 

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