SLIPSTREAM--The stream of air driven
PYLON--A structure or strut that supports
backward by a rotating propeller.
an engine pod, external tank, etc., on an aircraft.
SLUGGING--In airplanes, loss of liquid fuel
QEC--Quick engine change.
from tank vents because of the pulling action of
escaping vapors.
QECAQuick engine change assembly.
SOAPSTONE--A hand talc with a soapy or
QECKQuick engine change kit.
greasy feel.
RAM AIR--Air forced into an air intake or
SPECIFIC GRAVITY--The ratio of the
duct by the motion of the intake or duct through
weight of a given volume of a substance to the
the air.
weight of an equal volume of some standard
substance, such as water.
RAM PRESSURE--Air pressure in the inlet
caused by a jet aircraft's forward motion.
SPECTROMETER--An optical device used
to determine the amounts and types of con-
RATIO--The relation between two similar
taminants in oil sample droplets under the Navy
items in respect to the number of times the first
Oil Analysis Program.
contains the second.
SPEED--The distance a body in motion
RESERVOIR--A receptacle or chamber for
travels per unit of time.
holding a liquid or fluid.
STATOR--A system of stationary airfoils.
ROTOR--A system of rotating airfoils.
SUMP--A chamber into which a fluid drains
RPM--Revolutions per minute.
for pickup and recirculation.
SCAVENGE OIL--The term used for oil that
T--Abbreviation for temperature. Combined
has been through the engine lubrication system
with a number it will indicate temperature at a
and is on its way back to the tank.
specific engine station. For example, T2 indicates
compressor inlet temperature.
SCUPPER--Any drain for fluid runoff.
T E F L O N--Trademark used in making a
SE--Support equipment. All of the equipment
tough, nonsticking coating for gaskets, backup
on the ground needed to support aircraft in a state
rings, bearings, electrical insulators, etc.
of readiness for flight.
TENSION--A force or pressure that exerts a
SEGTE--Support equipment gas turbine
pull or resistance.
engine.
THERMOCOUPLE--A device for measuring
S E L E C T O R VALVE--A valve used to
temperature, consisting of two dissimilar metallic
c o n t r o l the flow of fluid to a particular
conductors joined at their ends.
mechanism, as in a hydraulic system.
THERMODYNAMICS--The science con-
SERVICING--The refilling of an aircraft
cerned with the relations between heat and
with consumables such as fuel, oil, and com-
mechanical energy or work, and the conversion
pressed gases to predetermined levels, pressures,
of one to the other.
quantities, or weights.
THRUST--The forward-direction pushing or
SHALL--Term indicating that application of
pulling force developed by an aircraft engine or
a procedure is mandatory.
rocket engine.
SHOULD--Term indicating that application
TORQUE--A turning or twisting force.
of a procedure is recommended.
AI-5
