the Aviation Dictionary

temperature and remain in a combined solid state when
rapidly cooled.
solidity ratio - In rotorcraft, the ratio of the total rotor
blade area to total rotor disc area.
solid-state device - An electronic device that controls
the flow of electrons without any mechanical
operations. Also referred to as a semiconductor.
solo flight - Refers to one person piloting an aircraft in
flight with no passengers.
solidity ratio . span of an airfoil
sonic rate while simultaneously penetrating any surface
oxide..
sonic speed - The speed sound travels through a
medium.
sonic vibration - A high-frequency vibration caused by
sound energy.
- ~
soot - A black residue created during oxyacetylene
welding when the burning acetylene gas does not have
enough oxygen to be completely consumed.
solstice -Noon the first day of summer and the first day sound - A mechanical radiant energy transmitted by
of winter, when the sun has reached its highest and longitudinal pressure waves in the material medium. Its
lowest latitudes, respectively.
frequency is perceived by the human ear.
soluble - Any substance that can be combined with
another substance. An example of this is mixing water
and crystalline sugar to form sugar water.
solution - 1. A state in which base metal and alloying
agents are united to form a single, solid metal. 2. A
combination of a solid, liquid, or gaseous substance
homogeneously mixed with a liquid, gas, or solid.
solution heat treatment - A heat treatment of
aluminum alloy where metal is raised to its heat
treating temperature, held until uniform throughout,
and then quenched. This process covers alloying agents
held in solid solution, which increases the strength of
the metal.
sound suppressor - Same as noise suppressor in
reference to engines. Also, a device on a test cell that
reduces the sound of exhaust stack noises.
sound waves - Longitudinal wave motion through
matter. Longitudinal waves vibrate back and forth
longitudinally in the direction of wave propagation.
sounding - 1. In meteorology, an upper-air observation;
a radiosonde or rawinsonde observation. 2. The
electrode of a field-effect transistor similar to the
emitter of an ordinary transistor. 3. In communication,
the sender, speaker, transmitter, or instructor who
composes and transmits a message made up of
symbols, which are meaningful to listeners and readers.
solvent - A liquid used for dissolving and cleaning south geographic pole - The pole located at the 90th
materials.
degree of south latitude. The south geographic pole of
the Earth is located at the southern-end of the~arth's
sonar - A system that detects objects in the water by
axis.
sending out sound waves and receiving the echoes.
operais similar to radar. The acronym for Sound south pole of a magnet - The pole of a magnet where
NAvigation Ranging.
lines of flux enter the magnet. Lines of flux are
sonic - Relating to the speed of sound. Subsonic is
considered to leave the magnet at the north pole.
speed below the speed of sound; transonic is speed space charge - The electric charge carried by a cloud of
bridging the speed of sound; and supersonic refers to electrons in the space between electrodes of an electron
speed - neater than the weed of sound. The s~eed of tube.
sound is approximately 761 miles per hour at sea level,
space shuttle - A reusable aerospace vehicle designed
59°F.
for carrying passengers and cargo into Earth's orbit and
sonic boom - A vibrational disturbance, heard as a loud subsequently returning for landing.
noise, caused by an airplane moving faster than the
spacers - Devices or components used to take up space
speed of sound.
between two obiects.
sonic cleaning - A method of cleaning parts using high
spaghetti - Insulating tubing slipped over wires.
intensity sound waves in a cleaning - fluid.
spalling - A bearing defect in which chips of the
sonic frequencies - High frequency vibrational
hardened bearing surface are broken out.
disturbances that the human ear can detect, normally
considered to be the frequencies between 20 and span - 1. Length dimension of a beam. 2. In rotorcraft,
20,000 Hz. the dimension of a rotor blade or airfoil from root to
sonic soldering - A method of soldering certain metals
tip.
such as aluminum that are difficult to solder because span loading - The ratio between the weight of an
they quickly build up surface oxides. The tip of a sonic airplane and the span of its wings.
soldering iron heats the surface by vibrating it at a
span of an airfoil - The length of an airfoil measured
from tip to tip.
Aircraft Technical Book Company
P.O. Box 270
Tabernash, CO 80478
http:llwww.ACTechbooks.com