the Aviation Dictionary

deicing -Removing
ice after it has formed.
de-icing equipment - Aircraft equipment that is
actuated to remove ice from the structure of the aircraft
that has already formed.
deicing fluid - A liquid (usually heated) that is sprayed
on an aircraft to remove ice. Deicing fluid prevents the
retum of ice for a specified period of time.
delaminate - In composites, the separation of layers due
to adhesive failure. This also includes the separation of
the layers of fabric to a core structure. A delamination
may be associated with bridging, drilling, and
trimming.
delaminated - 1. A condition caused by exfoliation
corrosion in which the layers of grain structure in an
extrusion separate from one another. 2. Separation of
the core and face sheets of a bonded structure along a
bond line.
deicing departure center
demodulation - The recovery of the signal from a radio
frequency carrier wave. Also referred to as detection.
demonstration stalls - Stalls that the instructor
demonstrates mainly as an in-flight portion of stalllspin
awareness training. The flight instructor PTS lists these
stalls, categorizes them, and explains the knowledge
and skill associated with successful performance.
Advise student pilots that demonstration stalls are not
to be practiced in solo flight. Like other flight
maneuvers, perform demonstration stalls at an altitude
that allows for recovery above 1,500 ft. AGL.
demonstration-performance method - An educational
presentation in which an instructor first shows the
student the correct way to perform an activity and then
has the student attempt the same activity.
demulsibility - The measure of an oil's ability to
separate from water.
demulsifier - A system or substance that causes an
delay indefinite (reason if known) expect further
emulsion (mixture) of two or more substances to break
clearance (time)- Used by ATC to inform a pilot
down into component materials.
when an accurate estimate of the delay time and the
reason for the delay cannot immediately be determined; denatured alcohol - Grain alcohol (ethyl alcohol or
e.g., a disabled aircraft on the runway, terminal or ethanol) with substances added to make it unfit for
center area saturation, weather below landing human consumption without affecting its use for other
minimums, etc.
purposes.
delay time - The amount of time that the arrival must denial of reality -A psychological defense mechanism
lose to cross the meter fix at the assigned meter fix where students may ignore or refuse to acknowledge
time. This is the difference between ACLT and VTA. disagreeable - realities. They may turn away from
unpleasant sights, refuse to discuss unpopular topics, or
delta - Greek letter (A) used in weight and balance
reject criticism.
computations to indicate amount of change.
denier - A numbering system for filaments in the yam
delta connection - A method of connecting three
used for weaving. The number is equal to the weight
components to form a three-sided circuit, usually
in grams of 9,000 meters of yam.
drawn as a triangle, hence the term delta.
denominate number - A number associated with a unit
delta hinge - The hinge located at the root end of the
of measurement.
rotor blade with its axis parallel to the plane of rotation
of the rotor that allows the blade to flap. The flapping denominator - The part of a fraction below the line
blade equalizes lift between the upwind and downwind indicating division. It is an indication of the number of
sides of the rotor disc.
parts into which a number is divided.
delta winding - The
connection of the windings
of three-phase AC machines.
The three windings are
connected together to form a
loop or a single path through
thethree windings.
delta wing - The triangular
wing planform of an aircraft.
demagnetize - To remove
magnetic properties from an
object.
demand oxygen system - Any oxygen system in which
the delivery of oxygen is metered according to the rate
and depth of a user's breathing.
Aircraft Technical Book Company
P.O. Box 270
Tabernash, CO 80478
http:llw.ACTechbooks.com
density - The mass of a substance per unit of its volume.
The weight per unit volume expressed in pounds per
cubic foot.
density altitude - Pressure altitude corrected for
nonstandard temperature variations.
dent - A depression in a surface usually caused by the
surface being struck by another object.
dented surface - A depression on a surface that usually
affects a small area. Cams, tappet rollers, and ball and
roller bearings are the parts most often involved.
departure center - The ARTCC having jurisdiction for
the airspace that generates a flight to the impacted
airport.