Pilot/Controller Glossary

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
MAINTAIN-
a. 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.)