Glossary of aviation
Terms
and abreviations.
KNOT - One nautical mile, about 1.15 statute miles (6,080');
eg: 125kts = 143.9mph.
LAMINAR-FLOW AIRFOIL - A low-drag airfoil designed to maintain
laminar flow over a high percentage of the chord about itself.
Often relatively thin, especially along the leading edge,
with most of its bulk near the center of the chord.
LANDING WIRES - Interplane bracing wires that help support
wingloads when the plane is on the ground. Direction of travel
is downward and outward from the fuselage. Opposite of FLYING
WIRES.
LIFT - The force exerted on the top of a moving airfoil as
a low-pressure area that causes a wingform to rise.
LIFT-DRAG RATIO - The lift coefficient of a wing divided
by the drag coefficient, as the primary measure of the efficiency
of an aircraft; aka L/D Ratio.
LIFT WIRES - Interplane bracing wires that help support wingloads
when the plane is in flight. Direction of travel is upward
from the bottom of the fuselage to the top of the interplane
struts. Also known as FLYING WIRES, the opposite of LANDING
WIRES.
LIGHT SPORT AIRCRAFT - Special FAA certification class (LSA)
for an aircraft other than a helicopter or powered-lift—single-engine
aircraft, airship, balloon, GLIDER, GYROCOPTER, ROTORCRAFT,
weight-shift-control aircraft. While limiting the types of
aircraft that could be flown by a Sport Pilot, it simplified
requirements for a obtaining a pilot license and did not require
a medical examination. SEE LSA feature.
LIQUID COMPASS - A non-electronic, calibratable compass floating
in a liquid as a panel instrument; aka Wet Compass.
LOAD FACTOR (g) - The proportion between lift and weight
commonly seen as g (sometimes capitalized)—a unit of
force equal to the force of gravity times one.
LOFTING - Design or fabrication of a complex aircraft component,
as with sheet metal, using actual-size patterns or plans,
generally laid out on a floor. The term is borrowed from boat
builders.
LONGERON - A principal longitudinal member of a fuselage's
framing, usually continuous across a number of supporting
points.
LOOP ANTENNA - A circular radio antenna, either in the open
or in a streamlined, teardrop housing, remotely turned 360°
to fine-tune a station in league with other radio-directive
devices. See also RADIO COMPASS, RADIO DIRECTION FINDER.
LORAN - Long Range Navigation system, which utilizes timing
differences between multiple low-frequency transmissions to
provide accurate latitude/longitude position information to
within 50'.
LTA - Lighter-than-air craft, generally referring to powered
blimps and dirigibles, but often also includes free balloons.
LUNKENHEIMER VALVE - A manual fuel drain placed handily along
a fuel line for checking avgas, such as for water or sediment
contaminations.
Mach or m. - A number representing the ratio of the speed
of an object to the speed of sound in the surrounding air
or medium in which it is moving.
MAGNETIC COMPASS - The most common liquid-type compass, capable
of calibration to compensate for magnetic influences within
the aircraft.
MAGNETIC COURSE - COMPASS COURSE ± deviation.
MAGNETIC NORTH - The magnetic North pole, located near 71°
North latitude and 96° West longitude, that attracts a
magnetic compass which is not influenced by local magnetic
attraction, as opposed to GEOGRAPHIC NORTH.
MAGNETO, MAG - An accessory that produces and distributes
a high-voltage electric current for ignition of a fuel charge
in an internal combustion engine.
MAGNUS EFFECT - The effect on a spinning cylinder or sphere
moving through a fluid, in which force acts perpendicular
to the direction of motion and to the direction of spin. This
is used to advantage in baseball, in which the trajectory
of a pitched ball is a distinct curve. Applied to aeronautics
in experimental wingforms, the Magnus Theory states that if
air is directed against a smooth, revolving cylinder, whose
circumferential speed is greater than that of the air current,
a force is directed against one side of the cylinder—air
compressed on one side and vacuum formed on the other—creating
lift. Named after physicist Heinrich Gustav Magnus (1802-70).
MARKER BEACON SEE RADIO NAVIGATION
MEAN SEA LEVEL SEE MSL
METAR - Acronym in FAA pilot briefings and weather reports
simply means an "aviation routine weather report,"
but nobody seems certain about the original source. The format
was introduced by the French on 1 Jan 1968, but was not adopted
by USA and Canada until 1 July 1996, and is thought to be
a contraction from MÉTéorologique ("Weather")
Aviation Règuliére ("Routine"). FAA
and NOAA specifically define METAR as "an approximate
translation from the French."
MOA SEE SPECIAL USE AIRSPACE
MONOCOQUE - Type of fuselage design with little or no internal
bracing other than bulkheads, where the outer skin bears the
main stresses; usually round or oval in cross-section. Additional
classifications are (1) Semi-Monocoque, where the skin is
reinforced by longerons or bulkheads, but with no diagonal
web members, and (2) Reinforced Shell, in which the skin is
supported by a complete framework or structural members. French:
monocoque,single shell.
MSL - Mean Sea Level. The average height of the surface of
the sea for all stages of tide; used as a reference for elevations,
and differentiated from AGL.
NACELLE - A streamlined enclosure or housing to protect something
such as the crew, engine, or landing gear. French: nacelle,from
Latin, navicella,little ship.
Paragliding Spain Center
