1Dk4eXg

shadowing
second derivative of refractive index (Schlieren = first
derivative).
shadowing Interference with an LOS communications
channel caused by parts of the aircraft.
shadow-mask tube Three-colour TV tube with three
guns projecting red/green/blue beams through mask with
about 500,000 holes.
shadow region Region where EM signals, eg radio or
radar, are poorly received, usually because of LOS
difficulties.
shadow shading Aircraft camouflage (UK, 1936-39).
shadow squadron Identity which a flying-training unit
would assume in war or national emergency (RAF).
Shaef Supreme HQ Allied Expeditionary Force (NW
Europe 1944-45).
Shaft Smart hard-target attack fuzing technology.
shaft Transmitter of torque joining two rotating assemblies,
such as a turbine and compressor. In a 3-* engine
the LP [fan] * passes down the engine centreline inside the
IP *, which in turn is surrounded for part of its length by
the HP *.
shaft horsepower Horsepower measured at an engine
output shaft, ignoring potentially useful energy in the
efflux. Also called torque hp and brake hp. Numerically
2π nQ where n is rpm and Q drive torque.
shaft power Power available from rotating shaft, =
torque × rpm.
shaft speed Rate of rotation, rpm or rad s -1 ; see rotational
speed.
shaft turbine Turboshaft engine, gas turbine providing
power at an output shaft, in some cases driven by free
turbine.
shaker 1 See vibration generator.
2 See stick*.
shaker speed IAS at which stick shaker is triggered.
shake-table test Any of various standard test schedules
for delicate items conducted on vibration generator to
simulate vibration in service (according to USAF ‘during
launch of missile or other vehicle’).
shale fuel Aviation jet fuel, notably JP-4, derived from
oil-bearing shales.
shall Shipborne [or shipboard] helicopter approach and
landing lighting.
Shamal NW wind bringing dust storms [Inaq].
Shanicle Radio guidance system of hyperbolic type used
on TM-61B cruise missile 1954: name from short-range
navigation vehicle.
shank Inner portion of some propeller blades where
section is not aerofoil but circular.
Shape Supreme HQ Allied Powers Europe [Belgium
B-7010] (Int.).
shape Appearance of electronic (eg radar) signal pulse
when plotted in form of amplitude against time. This
shape is not related to electronic shaping.
shaped-beam aerial One emitting beam whose main lobe
is shaped by electronic phasing.
shaped charge Hollow charge; warhead whose targetfacing
surface has form of re-entrant cone to generate
armour-piercing jet.
shaped-charge accelerator Propulsion system using a
shaped-charge propellant, a near-explosive, to achieve
highest possible speed of man-made object in atmosphere
after prior acceleration by rockets.
shear plan
shaped sonic boom Wavefront tailored for rapid attenuation,
so that it does not extend to Earth’s surface.
shaper Machine tool having single unidirectional cutter
with horizontal (occasionally vertical) reciprocating
action.
shaping Particular electronic meaning is tailoring shape
of pulses or signal waveform, eg to assist manual
command guidance of RPV or missile.
SHAR, Shar Shriharikota Range (India).
Sharc Swedish highly advanced research configuration
(UAV).
shared aerial One used by several receivers.
Shares Shared airline reservations system (LA-based).
Shark Silent hard-kill [effective against switched-off
radars].
shark’s tooth Several definitions including “a Cuban
with straight lines and sharp corners”.
Sharp, SHARP 1 Standard hardware acquisition and
reliability program, which has addressed all military electronics
packaging, including shift from DIN to NAC
connector system (US).
2 Strapdown heading and attitude-reference platform.
3 Shared reconnaissance pod.
4 System-oriented high-range-resolution automatic
target-recognition program (USAF).
sharp-edged gust Gust characterized by high rate of
change of vertical air velocity per unit horizontal distance
at particular place, thus aircraft encounters full gust
vertical velocity almost instantaneously.
Shars Strapdown heading and attitude reference
system.
shaving Finishing machine-tool cut removing very small
amount of metal; hence shave die, female die with cutting
edges for finish-cutting cams etc.
SHBL Solid hydrogen, boron lattice.
SHC Synthesized hydrocarbons.
shear Stress in which parallel planes of loaded material
tend to slide past each other; hence also deliberate cutting
action by cutting edges which slide past each other.
shear centre Of a wing, axis about which wing deflects in
torsion, also called flexural centre of elastic axis.
shear force Vertical load, especially on the fuselage,
usually integrated from tail to nose along the longitudinal
axis.
shearing Cutting workpiece or material by shears
without formation of chips.
shear lag Structural stress diffusion in which lag of
longitudinal displacement of one part of longitudinal
section relative to another is result of shear applied
parallel to length of structure.
shear load Load (force) applied in shear, eg of engine
pod on wing spar.
shear modulus E s , modulus of rigidity, approximately
half modulus of elasticity.
shear neck Local reduction in diameter or wall-thickness
of a shaft to ensure that, in event of sudden increase
in load [eg from something jamming gearteeth], failure
will occur at this point.
shear nut Thin nut used on bolt where load is entirely in
shear, merely to retain bolt.
shearout An interconnection or axle [eg in powered
flight control] designed to break if overloaded.
shear plan Lofting plan of body, eg fuselage, flying-boat
609