M Flashcards
Mach number
The ratio of the true airspeed of the aircraft
to the speed of sound in the same atmospheric conditions,
named in honor of Ernst Mach, late 19th century physicist
Mach meter
The instrument that displays the ratio of the
speed of sound to the true airspeed an aircraft is flying.
Magnetic Bearing (MB)
The direction to or from a radio
transmitting station measured relative to magnetic north.
Magnetic compass
A device for determining direction measured from magnetic north.
Magnetic dip
A vertical attraction between a compass
needle and the magnetic poles. The closer the aircraft is to a
pole, the more severe the effect.
Magnetic Heading (MH)
The direction an aircraft is pointed with respect to magnetic north
Magneto
A self-contained, engine-driven unit that supplies
electrical current to the spark plugs; completely independent
of the airplane’s electrical system. Normally there are two
magnetos per engine.
Magnus effect
Lifting force produced when a rotating
cylinder produces a pressure differential. This is the same
effect that makes a baseball curve or a golf ball slice.
Mandatory altitude
An altitude depicted on an instrument
approach chart with the altitude value both underscored and
overscored. Aircraft are required to maintain altitude at the
depicted value.
Mandatory block altitude
An altitude depicted on an
instrument approach chart with two underscored and
overscored altitude values between which aircraft are
required to maintain altitude.
Maneuverability
Ability of an aircraft to change directions
along a flightpath and withstand the stresses imposed upon
it.
Maneuvering speed (VA)
The maximum speed at which full,
abrupt control movement can be used without overstressing
the airframe.
Manifold absolute pressure
The absolute pressure of the
fuel/air mixture within the intake manifold, usually indicated
in inches of mercury.
Margin identification
The top and bottom areas on an
instrument approach chart that depict information about
the procedure, including airport location and procedure
identification
Marker beacon
A low-powered transmitter that directs its
signal upward in a small, fan-shaped pattern. Used along the
flight path when approaching an airport for landing, marker
beacons indicate both aurally and visually when the aircraft
is directly over the facility.
Mass
The amount of matter in a body.
Maximum altitude
An altitude depicted on an instrument
approach chart with overscored altitude value at which or
below aircraft are required to maintain altitude.
Maximum Authorized Altitude (MAA)
A published altitude
representing the maximum usable altitude or flight level for
an airspace structure or route segment.
Maximum landing weight
The greatest weight that an airplane normally is allowed to have at landing.
Maximum ramp weight
The total weight of a loaded
aircraft, including all fuel. It is greater than the takeoff
weight due to the fuel that will be burned during the taxi
and runup operations. Ramp weight may also be referred to
as taxi weight.
Maximum takeoff weight
The maximum allowable weight for takeoff.
Maximum weight
The maximum authorized weight of
the aircraft and all of its equipment as specified in the Type
Certificate Data Sheets (TCDS) for the aircraft.
Maximum zero fuel weight (GAMA)
The maximum weight, exclusive of usable fuel.
Mean Aerodynamic Chord (MAC)
The average distance
from the leading edge to the trailing edge of the wing.
Mean sea level
The average height of the surface of the
sea at a particular location for all stages of the tide over a
19-year period.
Meridians
Lines of longitude
Mesosphere
A layer of the atmosphere directly above the stratosphere.
MHz
Megahertz
Microbursts
A strong downdraft which normally occurs over
horizontal distances of 1 NM or less and vertical distances of
less than 1,000 feet. In spite of its small horizontal scale, an
intense microburst could induce windspeeds greater than 100
knots and downdrafts as strong as 6,000 feet per minute.
Microwave Landing System (MLS)
A precision instrument
approach system operating in the microwave spectrum which
normally consists of an azimuth station, elevation station,
and precision distance measuring equipment.
Mileage breakdown
A fix indicating a course change
that appears on the chart as an “x” at a break between two
segments of a federal airway.
Military Operations Area (MOA)
Airspace established for
the purpose of separating certain military training activities
from IFR traffic.
Military Training Route (MTR)
Airspace of defined vertical
and lateral dimensions established for the conduct of military
training at airspeeds in excess of 250 knots indicated airspeed
(KIAS).
Minimum altitude
An altitude depicted on an instrument
approach chart with the altitude value underscored. Aircraft are
required to maintain altitude at or above the depicted value.
Minimum Crossing Altitude (MCA)
. The lowest allowed
altitude at certain fixes an aircraft must cross when proceeding
in the direction of a higher minimum en route altitude
(MEA).
Minimum Descent Altitude (MDA)
The lowest altitude (in
feet MSL) to which descent is authorized on final approach,
or during circle-to-land maneuvering in execution of a
nonprecision approach.
Minimum drag
The point on the total drag curve where
the lift-to-drag ratio is the greatest. At this speed, total drag
is minimized.
Minimum en route altitude (MEA)
The lowest published
altitude between radio fixes that ensures acceptable
navigational signal coverage and meets obstacle clearance
requirements between those fixes.
Minimum Equipment List (MEL)
A list developed for larger
aircraft that outlines equipment that can be inoperative for
various types of flight including IFR and icing conditions. This
list is based on the master minimum equipment list (MMEL)
developed by the FAA and must be approved by the FAA for
use. It is specific to an individual aircraft make and model.
Minimum Obstruction Clearance Altitude (MOCA)
The
lowest published altitude in effect between radio fixes on VOR
airways, off-airway routes, or route segments, which meets
obstacle clearance requirements for the entire route segment
and which ensures acceptable navigational signal coverage
only within 25 statute (22 nautical) miles of a VOR.
Minimum Reception Altitude (MRA)
The lowest altitude at which an airway intersection can be determined.
Minimum Safe Altitude (MSA)
The minimum altitude
depicted on approach charts which provides at least 1,000 feet
of obstacle clearance for emergency use within a specified
distance from the listed navigation facility.
Minimum Vectoring Altitude (MVA)
An IFR altitude lower
than the minimum en route altitude (MEA) that provides
terrain and obstacle clearance.
Minimum section
The area on an IAP chart that displays the lowest altitude and visibility requirements for approach.
Missed approach
A maneuver conducted by a pilot when an
instrument approach cannot be completed to a landing.
Missed Approach Point (MAP)
A point prescribed in each
instrument approach at which a missed approach procedure
shall be executed if the required visual reference has not
been established.
Mixed ice
A mixture of clear ice and rime ice
MM
Middle Marker
Mode C
Altitude reporting transponder mode
Moment
The product of the weight of an item multiplied
by its arm. Moments are expressed in pound-inches (lb-in).
Total moment is the weight of the airplane multiplied by the
distance between the datum and the CG.
Moment arm
The distance from a datum to the applied force.
Moment index (or index)
A moment divided by a constant
such as 100, 1,000, or 10,000. The purpose of using a moment
index is to simplify weight and balance computations of
airplanes where heavy items and long arms result in large,
unmanageable numbers.
Monocoque
A shell-like fuselage design in which the
stressed outer skin is used to support the majority of imposed
stresses. Monocoque fuselage design may include bulkheads
but not stringers.
Monoplanes
Airplanes with a single set of wings.
Movable slat
. A movable auxiliary airfoil on the leading edge
of a wing. It is closed in normal flight but extends at high
angles of attack. This allows air to continue flowing over the
top of the wing and delays airflow separation.
Multi-Function Display (MFD)
. Small screen (CRT or LCD)
in an aircraft that can be used to display information to the
pilot in numerous configurable ways. Often an MFD will be
used in concert with a primary flight display.
