the Aviation Dictionary

anticyclone aperiodic damping
anticyclone - An area of high atmospheric pressure
which has a closed circulation that is anticyclonic, i.e.,
as viewed from above, the circulation is clockwise in
the Northern Hemisphere, counterclockwise in the
Southern Hemisphere.
antileak check valve - A check valve used to prevent
oil tank seepage to lower portions of the lube system
during periods on engine inactivity. Anti-leak check
valves hold the oil in the tank against the pull of
gravity. When the oil pump puts a low pressure on the
check valve, it opens and allows oil to flow from the
tank into the engine.
anticyclonic flow - In the Northern Hemisphere the
clockwise flow of air around an area of high pressure
and a counterclockwise flow in the Southern antimissile missile - A missile used to destroy another
Hemisphere.
missile.
antidetonant fluid - A fluid such as a waterlalcohol antimony -A silvery, metallic element with a symbol of
mix that enables more power to be obtained from the Sb and an atomic number of 51. Often used as an
engine when injected into the fuel/air stream. The fluid alloying agent with lead for use in lead-acid batteries.
itself does not increase the engine power; it merely
antipropeller end - The end of an engine away from the
replaces formerly excess fuel, allowing for a cooler
propeller.
operating engine. The waterialcohol dissipates heat
more rapidly than fuel. anti-servo tab - An
adjustable tab attached to
antidotes - A viable alternative to hazardous attitudes in
the trailing edge of a
aeronautical decision-making. Each of the five
stabilator that moves in the same direction as the
hazardous attitudes has an associated antidote, which
primary control. It is used to make the stabilator less
should be memorized and employed to minimize their
sensitive.
effects.
antiskid system - A system of controls for aircraft
antidrag wire - A diagonal, load-carrying member of a
brakes that releases the hydraulic pressure to the brake
Pratt truss wing. It runs from the rear spar inboard to
in the event the wheel begins to lock up or skid.
the front spar outboard, and it opposes tensile loads
tending to pull forward on the wing.-
antitear strips - Strips of aircraft fabric that are laid
- -
over the ;ing rib under the reinforcing tape before the
antifreeze - A chemical added to a liquid for the
fabric is stitched.
purpose of lowering its freezing point.
antitorque pedals - In rotorcraft, the pedals used to
antifriction bearings - Ball or roller bearings that have
control the pitch of the tail rotor or air diffuser in a
a special low drag quality.
NOTARO system. The pilot controls the pitch of the
antiglare paint - A black or dark paint that dries to a
dull or matte finish. It is applied to a surface to prevent
anti-torque rotor or the diffuser to position the
helicopter about its vertical axis.
glare From impairing the aircraft crew's vision.
anti-icing - The prevention of the formation of ice on a
surface. Ice may be prevented by using heat or by
covering the surface with a chemical that prevents
water from reaching the surface. Anti-icing should not
be confused with deicing, which is the removal of ice
after it has formed on the surface.
anti-icing equipment - Aircraft equipment used to
prevent structural icing.
anti-icing fluid - A fluid comprised of alcohol and
glycerin, used to prevent the formation of ice on the
leading edge of propellers, in the throat of a carburetor,
or on the windshield.
anti-icing system - 1. Any system or method used to
provide heat or supply anti-icing fluid to critical
external surfaces in order to preventice formation. 2. A
system in a gas turbine engine in which some of the hot
compressor bleed air is routed through the engine air
inlet system to wann it and prevent ice from forming.
antiknock rating - The rating of fuel that refers to the
ability of the fuel to resist detonation.
Aircraft Technical Book Company
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antitorque rotor - In rotorcraft, a rotor turning in a
plane perpendicular to that of the main rotor and
parallel to the longitudinal axis of the fuselage. It is
used to control the torque of the main rotor and to
provide movement about the yaw axis of the helicopter.
antiwindmilling brake - A friction brake fitted as an
accessory to the main gearbox of some older engines.
Seldom seen today. Note that the turboprops include a
brake in their propeller mechanisms, but it is not the
friction brake described here.
anvil - A hard-faced block on which a material is
hammered or shaped.
anvil cloud - The top portion of a cumulonimbus (Cb)
consisting primarily of cirrus cloud and a spread-out
area that, together, resemble an anvil.
anxiety - Mental discomfort that arises from the fear of
anything, real or imagined. May have a potent effect on
actions and the ability to learn from perceptions.
aperiodic damping - Damping that prevents an object
from over swinging, or moving past its at-rest position.
Also referred to as dead-beat damping.