CONVERGING--To tend to meet at a point
BERNOULLI'S PRINCIPLE--If a fluid
or line; incline toward each other.
flowing through a tube reaches a constriction, or
narrowing of the tube, the velocity of fluid flow-
COORDINATOR--An electromechanical
ing through the constriction increases and the
unit that mounts to the back of the fuel control
pressure decreases.
in turboprop engines. It coordinates the propeller,
BITE--Built-in test equipment.
electrical temperature datum control, and the fuel
control through signals received from the power
BTU--British thermal unit. A unit of heat
commonly used in heat engineering. It is the
amount of heat necessary to raise the temperature
COWLING--A removable cover or housing
of 1 pound of water 1 degree Fahrenheit.
placed over or around an aircraft component or
section, especially an engine.
CAUTION--An operating procedure, prac-
tice, or condition, etc., that may result in damage
CSE--Common support equipment.
or destruction to equipment if not carefully
observed or followed.
CURE--The changing of matrix properties
(hardening) by chemical reaction, usually ac-
CELSIUS--The temperature scale using the
complished with heat and vacuum pressure.
freezing point of water as zero and the boiling
point as 100, with 100 equal divisions between
CYCLIC PITCH--The mechanical means to
called degrees. A reading is usually written in the
change the pitch of the main rotor blades during
abbreviated form; for example, 75C. This scale
the rotor system cycle of rotation to control the
was formerly known as the centigrade scale, but
tilt of the rotor disk.
was renamed Celsius in recognition of Anders
Celsius, the Swedish astronomer who devised the
DE-ICING--The breaking off or melting of
scale.
ice from aircraft surfaces or fuel induction
systems.
CENTRIFUGAL--Moving or directed out-
ward away from the center or axis.
DELAMINATE/DELAMINATION--The
splitting or separating of a laminated composite
COLLECTIVE PITCH--The mechanical
material between laminate plies.
means of simultaneously increasing or decreas-
ing the pitch of all main rotor blades.
DENSITY--The weight per unit volume of a
COMPRESSOR INLET TEMPERATURE
substance.
(CIT or T2)--The temperature of the air entering
the gas turbine compressor as measured at the
DIFFUSER--A specially designed duct,
front frame. One of the parameters used to
chamber, or section equipped with guide vanes,
calculate engine power output (torque) and
which decrease velocity and increase pressure.
scheduling combustion fuel flow and variable
stator vane angle.
DILUTENT--A substance or medium to
reduce strength or make thinner.
CONCENTRIC--Having a common center.
DISILICATES--Compounds containing two
CONDENSATION--The act of reducing a
atoms of silicon in conjunction with other
gas or vapor to a liquid or solid form.
elements.
CONING--The upward flexing of the rotor
DISSIPATE--To scatter or spread.
blades resulting from the vectorial combined
effects of centrifugal force and lift.
DIVERGENT--To extend in different direc-
tions from a common point.
CONTAMINATION--Any foreign material
or substance whose presence (in the fluid) is
DYNAMICALLY--As in balanced by
capable of adversely affecting the performance
rotating at high speed.
or reliability of a system.
AI-2
