Glossary

Maneuverability. Ability of an aircraft to change directions MB. See magnetic bearing. along a flight path and withstand the stresses imposed upon it. MCA. See minimum crossing altitude. Maneuvering speed (V ). The design maneuvering speed. A Operating at or below design maneuvering speed does not MDA. See minimum descent altitude. provide structural protection against multiple full control inputs in one axis or full control inputs in more than one MEA. See minimum en route altitude. axis at the same time. Mean aerodynamic chord (MAC). The average distance Manifold absolute pressure. The absolute pressure of the from the leading edge to the trailing edge of the wing. fuel/air mixture within the intake manifold, usually indicated in inches of mercury. Mean sea level. The average height of the surface of the sea at a particular location for all stages of the tide over a MAP. See missed approach point. 19-year period. Margin identification. The top and bottom areas on an MEL. See minimum equipment list. instrument approach chart that depict information about the procedure, including airport location and procedure Meridians. Lines of longitude. identification. Mesophere. A layer of the atmosphere directly above the Marker beacon. A low-powered transmitter that directs its stratosphere. signal upward in a small, fan-shaped pattern. Used along the flight path when approaching an airport for landing, marker METAR. See Aviation Routine Weather Report. beacons indicate both aurally and visually when the aircraft is directly over the facility. MFD. See multi-function display. Mass. The amount of matter in a body. MH. See magnetic heading. Maximum altitude. An altitude depicted on an instrument MHz. Megahertz. approach chart with overscored altitude value at which or below aircraft are required to maintain altitude. Microburts. A strong downdraft which normally occurs over horizontal distances of 1 NM or less and vertical Maximum authorized altitude (MAA). A published altitude distances of less than 1,000 feet. In spite of its small representing the maximum usable altitude or flight level for horizontal scale, an intense microburst could induce an airspace structure or route segment. windspeeds greater than 100 knots and downdrafts as strong as 6,000 feet per minute. Maximum landing weight. The greatest weight that an airplane normally is allowed to have at landing. Microwave landing system (MLS). A precision instrument approach system operating in the microwave spectrum which Maximum ramp weight. The total weight of a loaded aircraft, normally consists of an azimuth station, elevation station, including all fuel. It is greater than the takeoff weight due to the and precision distance measuring equipment. fuel that will be burned during the taxi and runup operations. Ramp weight may also be referred to as taxi weight. Mileage breakdown. A fix indicating a course change that appears on the chart as an “x” at a break between two Maximum takeoff weight. The maximum allowable weight segments of a federal airway. for takeoff. Military operations area (MOA). Airspace established for Maximum weight. The maximum authorized weight of the purpose of separating certain military training activities the aircraft and all of its equipment as specified in the Type from IFR traffic. Certificate Data Sheets (TCDS) for the aircraft. Maximum zero fuel weight (GAMA). The maximum weight, exclusive of usable fuel. G-19