| M | Mach number (followed by figures) |
| M | Metres (preceded by figures) |
| MAA | Maximum authorized altitude |
| MACC | Military area control centre |
| MAG | Magnetic |
| MAINT | Maintenance |
| MAP | Aeronautical maps and charts |
| MAPP | Military approach control unit |
| MAPT | Missed approach point |
| MAR | March |
| MAX | Maximum |
| MAY | May |
| MCA | Minimum crossing altitude |
| MCTR | Military control zone |
| MDA | Minimum descent altitude |
| MDF | Medium frequency direction − finding station |
| MDH | Minimum descent height |
| MEA | Minimum en−route altitude |
| MEHT | Minimum eye height over threshold (for visual approach slope indicator system) |
| MET | Meteorological or meteorology |
| METAR | Aerodrome routine meteorological report (in meteorological code) |
| METREPORT | Local routine meteorological report (in abbreviated plain language) |
| MF | Medium frequency (300 to 3 000 kHz) |
| MHDF | Medium and high frequency direction − finding stations (at the same location) |
| MHVDF | Medium, high and very high frequency direction – fading stations (at the same location) |
| MHZ | Megahertz |
| MID | Mid−point (related to RVR) |
| MID | Middle and Far−East |
| MIFG | Shallow fog |
| MIL | Military |
| MIN | Minutes |
| MKR | Marker radio beacon |
| MLS | Microwave landing system |
| MM | Middle marker |
| MNM | Minimum |
| MNPS | Minimum navigation performance specifications |
| MNTN | Maintain |
| MOA | Military operating area |
| MOC | Minimum obstacle clearance (required) |
| MOD | Moderate (used to indicate the intensity of weather phenomena, interference or static reports, e.g. MOD RA = moderate rain) |
| MON | Monday |
| MOPS | Minimum operational performance standards |
| MOTNE | Meteorological Operational Telecommunications Network Europe |
| MOV | Move or moving or movement |
| MPS | Metres per second |
| MRA | Minimum reception altitude |
| MRG | Medium range |
| MRP | ATS/MET reporting point |
| MRVA | Minimum radar vectoring altitude |
| MS | Minus |
| MSA | Minimum sector altitude |
| MSG | Message |
| MSL | Mean sea level |
| MTMA | Military terminal control area |
| MTOM | Maximum take−off mass |
| MTOW | Maximum take−off weight |
| MTU | Metric units |
| MTW | Mountain waves |
| MTWR | Military aerodrome control tower |
| MVDF | Medium and very high frequency direction – fading stations (at the same location) |
| MWO | Meteorological watch office |
| MX | Mixed type of ice formation (white and clear) |
© 2012-21 Kristina Novotna