the Aviation Dictionary

mold. When the molten metal has hardened, the mold
is broken away.
sandbag - A heavy canvas or leather bag filled with
coarse sand. It is used as a surface to form sheet metal
by the bumping process. A bag filled with lead shot is
referred to as a shot bag.
sanding coat - A coat of surfacer or heavy bodied
material that is applied to a material and then sanded
off to fill small surface imperfections resulting in a
smoother surface for subsequent coats.
sandpaper - An abrasive paper made by bonding grains
of sand to the surface.
sandwich construction -A bonded structure in which a
core of material is inserted between two face sheets of
metal or fiberglass cloth. Core materials include
metallic or plastic honeycomb and end-grain balsa
wood. Sandwich construction is used when high
strength, light weight materials are required.
sandwich structure - In composites, a thick, low
density, core (Usually foam or honeycomb) between
thin faces of high strength material.
satellite - A man-made object that rotates around the
Earth. A small object that rotates around a larger
object.
saturate - A material that is thoroughly soaked, or
penetrated, to the extent that it cannot absorb any more
liquid.
sandbag. scavenge
transistor or vacuum tube has been reached. The
application of additional current to the base or gate has
no effect on the output.
sawtooth wave - The waveform produced by a
relaxation oscillator in which the voltage rises slowly
and drops rapidly.
say again - Used to request a repeat of the last
transmission. Usually specifies transmission or portion
thereof not understood or received; e.g., "Say again all
after ABRAM VOR."
say altitude - Used by ATC to ascertain an aircraft's
specific altitudelflight level. When the aircraft is
ciimbing or descenhing, the pilot should state the
indicated altitude rounded to the nearest 100 feet.
say heading - Used by ATC to request an aircraft
heading. The pilot should state the actual heading of
the aircraft.
Saybolt Seconds Universal (SSU) Viscosimeter - A
device that measures the viscosity of lubricating oils by
giving the time in seconds it takes for 60 cu. cm of oil
to flow through its calibrating orifice. Aviation 80
engine oil has an SSU viscosity of 79.2, and Aviation
100 oil has an SSU viscosity of 103.0.
S-band radar - Radar frequency range between 1,550
and 5,200 MHz.
scalar - A variable that only has magnitude such as
temperature and pressure compared to vector.
saturated adiabatic lapse rate (SALR)- The rate of scale - 1. A graduated measure. 2. An oxide of iron
decrease of temperature with height as saturated air is sometimes formed on the surfaces of hot forged
lifted with no - gain or loss of heat from outside sources. fasteners.
the adiabatic lapse rate (DALR), the SALR
seale eneel The change in any force coefficient such
is not a constant numerical value but varies with
as the drag coefficient due to a change in the value of
temperature, being greatest at low temperatures.
Reynold's number.
saturated adiabatic process - The rate at which
scale model - A smaller version of the original model
saturated air cools as it ascends. It is less than the dry
made in the same proportions.
adiabatic lapse rate because adiabatic cooling is offset
partially byAthe release of latent heat. The difference is scalene triangle - A three-sided form in which all sides
larger at higher temperatures.
and angles are unequal.
saturated air - Air containing the maximum amount of scales of circulations - The typical horizontal
water vapor it can hold at a given temperature (100% dimension size and lifetime of an individual
relative humidity).
circulation. See also macroscale, mesoscale, and
saturated vapor - The vapor state above a liquid in
microscale.
which no further vaporization can take place without scarf joint - A joint used for the construction or repair
an increase in temperature.
of a wooden aircraft or component. The two parts to be
saturated vapor pressure - The partial pressure of
joined are cut with a shallow taper and glued together.
water vapor at saturation. scarf patch -A flush repair to plywood skins where the
slope must be shallower than 1 in 12, or about 12 times
saturation - A state of equilibrium where the same
the thickness of the plywood.
amount of molecules are leaving a water surface as are
returning and the vapor pressures are balanced.
scavenge - To remove an undesirable material from an
saturation current - In electronics, the condition where
area.
the maximum amount of current able to flow in a
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