the Aviation Dictionary

visual learners . voltage regulator
visual learners - Students who learn best with their volatile liquid - A fast-evaporating fluid.
sense of sight. They prefer to absorb the big picture
volatile memory - In computers, a memory or storage
first, then break the information down into individual
device that loses its storage capability when power is
parts.
removed.
visual meteorological conditions (VMC) - volatile mineral spirit - A fast-evaporating petroleum
Meteorological conditions expressed in terms of
product used as a paint or varnish thinner and for
visibility, distance from cloud, and ceiling equal to or
preparing surfaces prior to painting.
better than specified minima.
volatiles - In composites, materials, such as water and
visual purple -- The chemical created by the rods that
alcohol, in a resin formulation, that are capable of
provides night vision acuity. The proper name is
being vaporized at room temperature.
rhodopsin.
visual range - See runway visual range.
volatility - The ease with which a fluid changes from a
liquid to a vapor.
visual separation - A means employed by ATC to
volcanic ash - In general, particulates and gases from a
separate aircraft in terminal areas and enroute airspace
in the NAS. There are two ways to effect this
volcanic eruption.
separation: VOLMET broadcast - Routine broadcast of
a. The tower controller sees the aircraft involved and meteorological information for aircraft in flight.
issues instructions, as necessary, to ensure that the
aircraft avoid each other.
volt - A unit of electromotive force (EMF) or potential
b. A pilot sees the other aircraft involved and upon
difference that is needed to force one ampere of
instructions from the controller provides his own
electrical flow through a resistance of one ohm.
separation by maneuvering his aircraft as necessary to voltage - The electric potential or potential difference
avoid it. This can involve following another aircraft or expressed in volts.
keeping it in sight until it is no longer a factor.
voltage amplifier - A circuit designed to maximize
vitrify - To convert a material into glass or a glass-like voltage gain at the expense of current gain or power
substance by heat and fusion.
gain.
vivid color - Colors of very high intensity andfor
chroma. Sometimes used on aircraft for maximum
visibility.
VMc - Minimum controllable airspeed. VMc changes
with altitude and is considered the minimum airspeed
at which control of a multi-engine airplane can be
maintained with one engine inoperative.
VMc demonstration - This demonstration is required
during a multi-engine practical test to show the control
pressures necessary to maintain directional control with
one engine inoperative.
voice switching and control system (VSCS)- The
VSCS is a computer controlled switching system that
provides air traffic controllers with all voice circuits
(air to ground and ground to ground) necessary for air
traffic control.
voltage avalanche - The reverse voltage required to
cause a Zener diode to break down and begin
conducting.
voltage divider - A series of resistors placed across the
poles of a source to provide a number of different
voltages.
voltage doubler - A circuit that produces an output
voltage twice that of the input.
voltage drop - 1. The decrease in voltage in an
electrical circuit due to an increase in load. 2. The loss
in potential energy in a circuit when a current is made
to flow through a load and some of the energy is
converted from electrical energy into another form
such as heat.
voltage dropping resistor - A resistor placed in series
with some other comDonent in order to reduce the
void - 1. Unsatisfactory gaps in a weld. 2. An empty terminal voltage across or limit the current through that
area in the composite laminate. The term void can be component.
used in place of delamination. 3. Internal fissure in
ferrous materials. Also referred to as fish eye, chrome
quadrupler - In electricity, an amplifier whose
check, shatter crack, and snowflake.
output current is four times its input current.
volatile - A fluid easily vaporizable at relatively low
voltage regulation - -Maintaining a constant voltage
temperatures.
level despite fluctuating load current requirements.
volatile content - In composites, the percent of volatiles regu1ator - A device that maintains a
that are driven off as a vapor from a plastic or an
constant-level voltage supply despite changes in input
impregnated reinforcement.
voltage or load.
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