Pilot/Controller Glossary

1300 Hz tone, which is received aurally and visually
by compatible airborne equipment.
(See INSTRUMENT LANDING SYSTEM.)
(See MARKER BEACON.)
(Refer to AIM.)

MILES-IN-TRAIL- A specified distance between
aircraft, normally, in the same stratum associated
with the same destination or route of flight.
MILITARY AUTHORITY ASSUMES RESPONSIBILITY FOR SEPARATION OF AIRCRAFT
(MARSA)- A condition whereby the military
services involved assume responsibility for separation between participating military aircraft in the
ATC system. It is used only for required IFR
operations which are specified in letters of agreement
or other appropriate FAA or military documents.
MILITARY LANDING ZONE- A landing strip used
exclusively by the military for training. A military
landing zone does not carry a runway designation.
MILITARY OPERATIONS AREA-
(See SPECIAL USE AIRSPACE.)

MILITARY TRAINING ROUTES- Airspace of
defined vertical and lateral dimensions established
for the conduct of military flight training at airspeeds
in excess of 250 knots IAS.
(See IFR MILITARY TRAINING ROUTES.)
(See VFR MILITARY TRAINING ROUTES.)

MINIMA-

which assures acceptable navigational signal coverage and meets obstacle clearance requirements
between those fixes. The MEA prescribed for a
Federal airway or segment thereof, area navigation
low or high route, or other direct route applies to the
entire width of the airway, segment, or route between
the radio fixes defining the airway, segment, or route.
(Refer to 14 CFR Part 91.)
(Refer to 14 CFR Part 95.)
(Refer to AIM.)

MINIMUM FRICTION LEVEL- The friction level
specified in AC 150/5320-12, Measurement, Construction, and Maintenance of Skid Resistant Airport
Pavement Surfaces, that represents the minimum
recommended wet pavement surface friction value
for any turbojet aircraft engaged in LAHSO. This
value will vary with the particular friction
measurement equipment used.
MINIMUM FUEL- Indicates that an aircraft"s fuel
supply has reached a state where, upon reaching the
destination, it can accept little or no delay. This is not
an emergency situation but merely indicates an
emergency situation is possible should any undue
delay occur.
(Refer to AIM.)

MINIMUM HOLDING ALTITUDE- The lowest
altitude prescribed for a holding pattern which
assures navigational signal coverage, communications, and meets obstacle clearance requirements.

(See MINIMUMS.)

MINIMUM CROSSING ALTITUDE (MCA)- The
lowest altitude at certain fixes at which an aircraft
must cross when proceeding in the direction of a
higher minimum en route IFR altitude (MEA).
(See MINIMUM EN ROUTE IFR ALTITUDE.)

MINIMUM DESCENT ALTITUDE (MDA)- The
lowest altitude, expressed in feet above mean sea
level, to which descent is authorized on final
approach or during circle-to-land maneuvering in
execution of a standard instrument approach
procedure where no electronic glideslope is provided.
(See NONPRECISION APPROACH
PROCEDURE.)

MINIMUM EN ROUTE IFR ALTITUDE (MEA)-
The lowest published altitude between radio fixes

MINIMUM IFR ALTITUDES (MIA)- Minimum
altitudes for IFR operations as prescribed in 14 CFR
Part 91. These altitudes are published on aeronautical
charts and prescribed in 14 CFR Part 95 for airways
and routes, and in 14 CFR Part 97 for standard
instrument approach procedures. If no applicable
minimum altitude is prescribed in 14 CFR Part 95 or
14 CFR Part 97, the following minimum IFR
altitude applies:
a. In designated mountainous areas, 2,000 feet
above the highest obstacle within a horizontal
distance of 4 nautical miles from the course to be
flown; or
b. Other than mountainous areas, 1,000 feet above
the highest obstacle within a horizontal distance of 4
nautical miles from the course to be flown; or