2/14/08 Pilot/Controller Glossary
PCG M-1
M
MAA-
(See MAXIMUM AUTHORIZED ALTITUDE.)
MACH NUMBER- The ratio of true airspeed to the
speed of sound; e.g., MACH .82, MACH 1.6.
(See AIRSPEED.)
MACH TECHNIQUE [ICAO]- Describes a control
technique used by air traffic control whereby turbojet
aircraft operating successively along suitable routes
are cleared to maintain appropriate MACH numbers
for a relevant portion of the en route phase of flight.
The principle objective is to achieve improved
utilization of the airspace and to ensure that
separation between successive aircraft does not
decrease below the established minima.
MAHWP- Missed Approach Holding Waypoint
MAINTAINa.
Concerning altitude/flight level, the term
means to remain at the altitude/flight level specified.
The phrase “climb and” or “descend and” normally
precedes “maintain” and the altitude assignment;
e.g., “descend and maintain 5,000.”
b. Concerning other ATC instructions, the term is
used in its literal sense; e.g., maintain VFR.
MAINTENANCE PLANNING FRICTION
LEVEL- The friction level specified in
AC 150/5320‐12, Measurement, Construction, and
Maintenance of Skid Resistant Airport Pavement
Surfaces, which represents the friction value below
which the runway pavement surface remains
acceptable for any category or class of aircraft
operations but which is beginning to show signs of
deterioration. This value will vary depending on the
particular friction measurement equipment used.
MAKE SHORT APPROACH- Used by ATC to
inform a pilot to alter his/her traffic pattern so as to
make a short final approach.
(See TRAFFIC PATTERN.)
MAN PORTABLE AIR DEFENSE SYSTEMS
(MANPADS)- MANPADS are lightweight, shoulder-
launched, missile systems used to bring down
aircraft and create mass casualties. The potential for
MANPADS use against airborne aircraft is real and
requires familiarity with the subject. Terrorists
choose MANPADS because the weapons are low
cost, highly mobile, require minimal set-up time, and
are easy to use and maintain. Although the weapons
have limited range, and their accuracy is affected by
poor visibility and adverse weather, they can be fired
from anywhere on land or from boats where there is
unrestricted visibility to the target.
MANDATORY ALTITUDE- An altitude depicted
on an instrument Approach Procedure Chart
requiring the aircraft to maintain altitude at the
depicted value.
MANPADS-
(See MAN PORTABLE AIR DEFENSE
SYSTEMS.)
MAP-
(See MISSED APPROACH POINT.)
MARKER BEACON- An electronic navigation
facility transmitting a 75 MHz vertical fan or
boneshaped radiation pattern. Marker beacons are
identified by their modulation frequency and keying
code, and when received by compatible airborne
equipment, indicate to the pilot, both aurally and
visually, that he/she is passing over the facility.
(See INNER MARKER.)
(See MIDDLE MARKER.)
(See OUTER MARKER.)
(Refer to AIM.)
MARSA-
(See MILITARY AUTHORITY ASSUMES
RESPONSIBILITY FOR SEPARATION OF
AIRCRAFT.)
MAWP- Missed Approach Waypoint
MAXIMUM AUTHORIZED ALTITUDE- A published
altitude representing the maximum usable
altitude or flight level for an airspace structure or
route segment. It is the highest altitude on a Federal
airway, jet route, area navigation low or high route,
or other direct route for which an MEA is designated
in 14 CFR Part 95 at which adequate reception of
navigation aid signals is assured.
MAYDAY- The international radiotelephony distress
signal. When repeated three times, it indicates
Pilot/Controller Glossary 2/14/08
PCG M-2
imminent and grave danger and that immediate
assistance is requested.
(See PAN‐PAN.)
(Refer to AIM.)
MCA-
(See MINIMUM CROSSING ALTITUDE.)
MDA-
(See MINIMUM DESCENT ALTITUDE.)
MEA-
(See MINIMUM EN ROUTE IFR ALTITUDE.)
MEARTS-
(See MICRO‐EN ROUTE AUTOMATED RADAR
TRACKING SYSTEM.)
METEOROLOGICAL IMPACT STATEMENTAn
unscheduled planning forecast describing
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