AERONAUTICAL GLOSSARY : MAXIMUM LANDING WEIGHT - MINIMUM EQUIPMENT LIST (MEL)

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 run up 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.

MERIDIANS—Lines of longitude.

MESOSPHERE—A layer of the atmosphere directly above the stratosphere.

METAR—See AVIATION ROUTINE WEATHER REPORT.

MICROBURST—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.

MILITARY OPERATION AREAS (MOA)—Airspace that consists of defined vertical and lateral limits established for the purpose of separating certain military training activity from IFR traffic. These are depicted on aeronautical charts.

MILITARY TRAINING ROUTES (MTR)—Routes developed to allow the military to conduct low altitude, high-speed training. These routes are identified on sectional charts.

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 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.

AERONAUTICAL GLOSSARY : LONGITUDE - MASS

LONGITUDE—Measurement east or west of the Prime Meridian in degrees, minutes, and seconds. The Prime Meridian is 0° longitude and runs through Greenwich, England. Lines of longitude are also referred to as meridians.

LONGITUDINAL AXIS—An imaginary line through an aircraft from nose to tail, passing through its center of gravity. The longitudinal axis is also called the roll axis of the aircraft. Movement of the ailerons rotates an airplane about its longitudinal axis.

LONGITUDINAL STABILITY (PITCHING)—Stability about the lateral axis. A desirable characteristic of an airplane whereby it tends to return to its trimmed angle of attack after displacement.

LORAN-C—A radio navigation system that utilizes master and slave stations transmitting timed pulses. The time difference in reception of pulses from several stations establishes a hyperbolic line of position, which can be identified on a LORAN chart. A fix in position is obtained by utilizing signals from two or more stations.

MAGNETIC BEARING—The magnetic course to go direct to an NDB station.

MAGNETIC COMPASS—A device for determining direction measured from magnetic north.

MAGNETIC DIP—Avertical attraction between a compass needle and the magnetic poles. The closer the aircraft is to the pole, the more severe the effect. In the Northern Hemisphere, a weight is placed on the south-facing end of the compass needle; in the Southern Hemisphere, a weight is placed on the north-facing end of the compass needle to somewhat compensate for this effect.

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.

MANEUVERABILITY—Ability of an aircraft to change directions along a flightpath and withstand the stresses imposed upon it.

MANEUVERING SPEED (VA) — The maximum speed where full, abrupt control movement can be used without overstressing the airframe.

MANIFOLD ABSOLUTE PRESSURE (MAP)—The absolute pressure of the fuel/air mixture within the intake manifold, usually indicated in inches of mercury.

MASS—The amount of matter in a body.

AERONAUTICAL GLOSSARY : JUDGMENT - LOAD FACTOR

JUDGMENT—The mental process of recognizing and analyzing all pertinent information in a particular situation, a rational evaluation of alternative actions in response to it, and a timely decision on which action to take.

LAND BREEZE—A coastal breeze flowing from land to sea caused by temperature differences when the sea surface is warmer than the adjacent land. The land breeze usually occurs at night and alternates with the sea breeze that blows in the opposite direction by day.

LATERAL AXIS—An imaginary line passing through the center of gravity of an airplane and extending across the airplane from wingtip to wingtip.

LATERAL STABILITY (ROLLING)—The stability about the longitudinal axis of an aircraft. Rolling stability or the ability of an airplane to return to level flight due to a disturbance that causes one of the wings to drop.

LATITUDE—Measurement north or south of the equator in degrees, minutes, and seconds. Lines of latitude are also referred to as parallels.

LEADING EDGE—The part of an airfoil that meets the airflow first.

LEADING EDGE DEVICES — High lift devices which are found on the leading edge of the airfoil. The most common types are fixed slots, movable slats, and leading edge flaps.

LEADING EDGE FLAP—A portion of the leading edge of an airplane wing that folds downward to increase the camber, lift, and drag of the wing. The leading-edge flaps are extended for takeoffs and landings to increase the amount of aerodynamic lift that is produced at any given airspeed.

LICENSED EMPTY WEIGHT— The empty weight that consists of the airframe, engine(s), unusable fuel, and undrainable oil plus standard and optional equipment as specified in the equipment list. Some manufacturers used this term prior to GAMA standardization.

LIFT—One of the four main forces acting on an aircraft. On a fixed-wing aircraft, an upward force created by the effect of airflow as it passes over and under the wing.

LIMIT LOAD FACTOR—Amount of stress, or load factor, that an aircraft can withstand before structural damage or failure occurs.

LOAD FACTOR—The ratio of the load supported by the airplane's wings to the actual weight of the aircraft and its contents. Also referred to as loading.