the Aviation Dictionary

semirigid rotor serrations
provide extra rigidity. Most of the larger modem
aircraft are of semi-monocoque construction.
semirigid rotor - In rotorcraft, a rotor system in which
the blades are fixed to the hub but are free to flap and
feather.
semispherical - In the shape of half a sphere. Domeshaped.
separator - 1. In composites, a permeable layer that
also acts as a release film. This could be in the form of
a peel ply or a porous Teflon@-coated fiberglass. Often
placed between lay-up and bleeder to facilitate the
excess resin wicking into the bleeder. It is removed
from the laminate after cure. 2. In batteries, a porous
material that keeps the positive and negative plates
apart and prevents them from shorting.
sender - In a fuel quantity system, a measuring device sequence valve - A mechanically actuated hydraulic
located in a reservoir or fuel tank. The sender consists valve causing a sequential action of certain actuators.
of a float mounted on an arm that rides on the top of Wheel-well doors, for example, must open and contact
the liquid. The arm is free to float and is connected to a a sequence valve before the landing gear can extend.
variable resistor. Any change in the fluid level sends a
sequential logic devices - A digital memory device
signal to an indicator on the pilot's instrument panel
whose output depends not only on current input but on
showing the amount of fluid in the tank.
past inputs as well.
sense antenna - A non-directional radio antenna that
serial number - A number indicating placement within
picks up a signal with equal strength from all
a series and used as a means of identification.
directions.
serial operation - In computers, operations are
sensible heat - Heat added to a substance that causes a
conducted one at a time rather than several operations
change in the temperature without changing the
occurring simultaneously (parallel operation).
substance's physical condition. Can be felt and
measured. opposite of latent heat
serialists - A learning style that starts with the
- -
components and pieces them together to understand the
sensitive altimeter - A pneumatic altimeter in which a
whole. Serialists prefer to start at the beginning and
pointer makes a complete revolution every thousand
examine the material in order.
feet. It also has an ad-justable barometric scale allowing -
it to be adjusted to the existing barometric pressure. series circuit - A circuit allowing only one path for
electron flow from the source through the load back to
sensitive relays - A relay that operates
the source.
electromagnetically with very small current. When the
relay closes it controls a larger current to operate other series ohmmeter - An ohmmeter circuit where
devices.
resistance is measured by determining the amount of
current flow through the unknown resistor by placing a
sensitivity - A measure of the ability of something to be
known voltage in series with the meter and the
sensitive or responsive to very small changes in
unknown resistor.
external conditions.
series resonant circuit - An AC circuit that has a
sensitized paper - Chemically treated paper used for
capacitor and an inductor connected in series. The
making photographic prints of drawings.
cavacitive reactance and the inductive reactance are
sensor - A device used to actuate signal-producing equal at the specific frequency of the circuit.
devices in response to changes in physical conditions.
series RLC circuit - An AC circuit where resistance,
sensory register - That portion of the brain that receives capacitance, and inductance are arranged so that all
inuut from the five senses. The individual's current must flow through - all three elements.
preconceived concept of what is important will
series wound generator - A generator where the field
determine how much priority the register will give in
and armature are connected in series.
passing the information on to the rest of the brain for
action.
series-parallel circuit - A circuit consisting of groups
- - A
of parallel components connected in series with other
separation - 1. Phenomenon occurring when a moving
components.
stream of fluid flowing past a body separates from the
surface of that body. 2. Spacing between aircraft, levels series-wound motor - An electric motor with
or tracks.
electromagnetic field coils connected in series with the
armature. Series-wound motors are used as starter
separation minima - The minimum longitudinal,
motors because of their high starting torque.
lateral, or vertical distances by which aircraft are
spaced through the application of air traffic control serrations - A formation resembling the teeth along the
procedures.
cutting edge of a saw.
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