| Acronym |
Definition |
| Mach number |
Ratio of true airspeed to the speed of sound. |
| MAP |
Missed Approach Point. |
| Marker Beacons (mkrs) |
Part of an instrument landing system using 75 MHz transmitters emitting fan-shaped or elliptical signal patterns vertically upwards, defining specific points along the glideslope. Markers provide aural and visual indications on a cockpit marker beacon receiver. |
| MATZ |
Military Aerodrome Traffic Zone. |
| Mayday |
International radio distress call. |
| Mb |
Millibar. |
| MDA |
minimum descent altitude. |
| MEDA |
Military Emergency Diversion Airfield. |
| Met |
Meteorology, weather. |
| METAR |
Coded aerodrome Met report. |
| MF |
Medium Frequency. Radio waves with frequencies in the 300- 3,000 kHz range. |
| MFA |
Military Flying Area |
| MFD |
Multi-Function Display - selectable displays of weather radar, navigation maps, checklists and data other than primary flight information. |
| MH |
Magnetic Heading |
| MHz |
Megahertz, the frequency of radio carrier waves measured in millions of cycles per second. |
| Minimums |
Weather condition requirements for a particular mode of flight. |
| MLS |
Microwave Landing System. |
| MMARS |
Military Middle Airspace Radar Service, available to military and civil aircraft operating in UK airspace between FL100 and FL245. |
| MOA |
Military Operations Area. |
| Mogas |
car fuel, approved for use in some light aircraft subject to certain conditions. |
| MPA |
Man-Powered Aircraft |
| MSA |
Minimum Sector Altitude Or Minimum Safe Altitude. |
| MSL |
Mean Sea Level |
| MTBF |
Mean Time Between Failures. Also MTTR, mean time to repair |
| MTMA |
Military Terminal Control Area. |
