the Aviation Dictionary

locator longeron
locator - An L/MF NDB used as an aid to final
approach. Note: A locator usually has an average
radius of rated coverage of between 18.5 and 46.3 km
(10 and 25 NM)
lock tabs -A washer with tabs that are bent to prevent a
nut from loosening.
locked-rotor current - The amount of current flowing
through the windings of an electric motor when the
motor is prevented from turning. This is the highest
current draw of the motor since once the motor starts
rotating, counter electromotive force (CEMF) is
generated in the windings that opposes voltage and, in
turn, current flow through the windings.
lockout debooster - A hydraulic component that
decreases the pressure applied to aircraft brakes. Its
lockout function shuts off all flow of fluid to the brake
in the event of a rupture of the brake line below the
debooster.
lockring - A horseshoe-shaped ring that snaps into a
groove on a shaft in order to hold the shaft in position.
lockstitch - A modified seine knot used to lock the
stitches when hand sewing aircraft fabric. The baseball
stitch is used for sewing and it is locked with the seine
knot every eight to ten stitches to prevent loosening.
locktab - A mechanical lock used to prevent a nut from
coming loose. Its appearance is similar to a washer but
with notches cut from the periphery. When a locktab is
ulaced under a nut on the shaft of a bolt. one or more of
the external locking tabs are bent up against the flats of
the nut to keep it from backing off and becoming loose.
lockwire - A stainless steel, brass, or galvanized steel
wire used to exert a pulling motion on the head of
screws or bolts to prevent them from loosening. Also
referred to as safetywire.
lockwiring - A method of tying two or more screws or
bolts together by twisting lockwire between them in
such a way that tension is held on the head of each
fastener in the direction of tightening.
lodestone - A natural rock having magnetic
characteristics.
log - A journal containing a record of activities. Pilots
keep a log of their flight time, and ground crews keep
logs on the mechanical operating components of the
aircraft, airframe, engine, propeller, and rotor to show
the amount of time in service, and to record all the
maintenance that has been completed on each device.
logarithm - The exponent that indicates the power to
which a number is raised to produce a given number.
For 5' = 25, the logarithm of 25 to the base 5 is 2.
logarithmic or audio taper potentiometer - A volume
control potentiometer whose resistance decreases
(volume increases) logarithmically as the control shaft
is rotated in a clockwise direction.
logbooks, mechanical - The journals containing records
of the total operating time, repairs, alterations or
inspections performed, and all AD notes complied
with. A mechanical logbook should be kept for the
airframe, for each engine, and for each propeller.
logic - Valid reasoning through facts and actuality.
logic circuit - A circuit designed to operate according to
the fundamental laws of logic.
logic flowchart - A flowchart that resembles a pert
chart, which graphically shows the flow of information
through a computer program, and the decisions that
must be made at various points. Boxes show
information, a diamond shaped figure is a logical
decision point, and a parallelogram is a point where
data is either put into or taken out of the program.
logic functions - Statements of logic conditions used in
digital computers. Usually associated with logic gates
such as AND, OR, NOT, NAND, NOR, and exclusive
OR. See also AND, OR, NOT, NAND, NOR, and
exclusive OR.
logic gate - See logic functions.
logic one - In logic functions, the ON, YES, or TRUE
choices that correspond to a binary "1 ."
logic state - The state or condition (logic one or zero) of
a digital
u
electronic conductor.
logic zero - In logic functions, the OFF, NO, or FALSE
choices that correspond to a binary "0."
logical one - A YES or a TRUE condition in digital
electronics. It is produced by a closed switch or the
presence of a voltage.
logical zero - A NO or a FALSE condition in digital
electronics. It is produced by an open switch or the
absence of a voltage.
long duct turbofan - A design that ducts the cold
stream to the rear of the engine and to the atmosphere.
The cold and hot streams mix on some engines.
long range navigation (LORAN) - An electronic
navigational system by which lines of position are
determined by measuring the difference in the time of
reception of synchronized pulse signals from fixed
transmitters
long waves - In meteorology, the wave-like structure in
the contour and westerly wind patterns in the mid- and
upper troposphere. Marked by long, (5,000 miles) slow
moving wave troughs located frequently along the east
coasts of both Asia and North America.
longeron - The main longitudinal strength-canying
member of an aircraft fuselage or engine nacelle.
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