the Aviation Dictionary

matter. medium bypass turbofan
matter - Any substance that has weight and occupies
space.
mature stage - In meteorology, the most intense stage
of a thunderstorm. Begins when the precipitationinduced
downdraft reaches the ground. usually lasts
about 20 minutes.
maximum authorized altitude (MU) - 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 FAR 95 at which
adequate reception of navigation aid signals is assured.
maximum except takeoff power (METO) - The
maximum continuous power an engine is allowed to
develop without any time restrictions.
measured ceiling - In weather, a classification where
the height of the ceiling has been determined (by one
of several measures) as opposed to estimated.
measuring circuit - Any combination of resistors,
batteries, and meters that-make it possible to measure
electrical values.
maximum allowable zero-fuel weight - The maximum mechanic - In aviation, a person certificated by the
weight authorized for an aircraft excluding its he1 FAA as an Airframe and Powerplant (A & P)
load.
mechanic. (Mechanics can be certified as either a
Powerplant and/or Airframe mechanic.) Aviation
Maintenance Technician (AMT) has become the
preferred term.
maximum landing weight - The maximum authorized
weight of the aircraft for landing.
maximum range - The maximum distance an aircraft
can travel by flying at the most economical speed and
altitude during all stages of flight.
maximum takeoff power - The maximum power an
engine is allowed to develop for a limited period of
time, usually about one minute.
maximum takeoff weight - The maximum design
weight of any aircraft for takeoff.
maximum weight - The maximum allowable weight for
an aircraft under anv conditions.
mechanical advantage - The increase in force or speed
gained by using such devices as levers, pulleys, gears,
or hydraulic cylinders.
mechanical blockage thrust reverser - A thrust
reverser usually of the post exit-type (clamshell) used
to reverse the hot exhaust stream of a gas turbine
engine to help slow the airplane during landings.
mechanical bond - The joining of two or more parts or
pieces by mechanical methods such as bolts, rivets, or
pins.
mechanical efficiency - The ratio of the brake
horsepower delivered to the output shaft of an engine
to its indicated horsepower.
mechanical energy - Energy that expresses itself in
mechanical movement or the physical production of
work.
mechanical linkage - A direct connection between a
control and a unit. No remote actuator.
mechanical mixture - A mixture of two or more
elements or compounds that can be identified by
maxwell - A unit of magnetic flux. One magnetic line of
microscopic examination.
force.
mechanical properties - Those properties that involve a
may - As related to aircraft maintenance, means that
relationship between strain and stress.
such an item is allowed, but not required.
mechanical turbulence - The turbulence that results
mayday - The international radiotelephony distress
when airflow is slowed by surface friction.
signal. When reveated three times. it indicates
inkinent and g;ave danger and that immediate median - In mathematics, the number in an ordered set
assistance is requested.
of values below and above which there is an equal
number of values. In the list 1,2,3,7,15,16, and 23, the
mean - The average of a number of factors. Often used
median is seven since there are three numbers smaller
to indicate the mid-point between two extremes.
and three numbers greater than seven. Note that this
mean aerodynamic chord (MAC)- The chord of an differs from the mathematical mean.
having the same medical certificate Short for FAA Aiman Medical
aerodynamic characteristics as that of the actual wing.
Certificate. Obtained by passing a physical
mean sea level (MSL)- The reference used for measuring
altitude above sea level. Mean sea level is the
average height of the surface of the sea.
mean solar day - The average time it takes the Earth to
rotate about its axis in one day.
Aircraft Technical Book Company
P.O. Box 270
Tabernash, CO 80478
http:llw.ACTechbooks.com
examination administered by a doctorwho is an FAAauthorized
Aviation Medical Examiner (AME).
medium bypass turbofan - Engines with 2:1 or 3:l
bypass ratios, which is the ratio of the amount of air the
fan moves (or bypasses) in relation to the core engine.
Also referred to as moderate bypass.