TWISTRotation of the suspension line
casing induced generally during final assembly of
the canopy, suspension lines and connector links.
TWIST OF THREAD OR CORDThe
direction (right or left) in which the strands of
thread or cord are wound around one another.
If the thread unwinds when turning it to the left,
it is right twist; if it tightens, it is left twist. Right
twist is also known as Z-twist. Left twist is also
known as S-twist.
TYPAbbreviation for typical.
UNDERFOLDInsufficient cloth folded
inside a seam. The raw edges of cloth will show
when underfold is excessive.
UNEVEN STITCHINGStitching wavy, or
number or stitches varying.
UNTACKTo remove a tacking. See also
V-RINGA metal fitting shaped in the form
of a closed letter V. For example, V-rings, used
with quick-ejector snap fittings, secure a harness
assembly on a wearer.
V-TABWebbing reinforcement at the point
where the suspension line enters the canopy.
VENTThe circular opening at the peak or
top of the canopy. As the parachute opens and
descends, some of the air in the canopy escapes
through this vent, thus reducing the strain on the
canopy and steadying descent. It is about 18
inches in diameter for personnel parachutes.
WARNINGIndicates danger to personnel.
The warning precedes the step or item to which
WARNING FLAGA tag attached to
an assembly, indicating that the assembly is
not operational. Often the flag is attached to
safety-pins on pyrotechnic devices to indicate
necessity of removal before operation. Also, it is
used to flag defective or incomplete equipment
to preclude use.
WARPThe threads that run parallel to the
selvage edge of cloth; those that are crossed by
the filling threads.
WEAVETo manufacture a web or cloth on
a loom by interlacing the warp and filling yams.
Also the particular pattern employed in weaving
cloth. The cloth for parachute use is one up and
one down (plain weave), two up and one down
(twill weave) or ripcord.
WEAVE SEPARATIONLooseness of
weave caused by strain or poor weaving.
WEB (WEBBING)A strong, narrow,
closely-woven tape of synthetic, cotton, or linen
fiber designed for bearing weight. For example,
it is used in the manufacture of the parachute
WEBBING, ELASTICA webbing having
elastic threads to give it greater elasticity than
regular webbing. It is used in the fabrication or
elastic ripcord pockets.
lengths of webbing sewn to the skirt hem at the
junction points of the suspension lines and the
WEBBING, TUBULARStrong synthetic or
natural fiber webbing woven in the form of a tube.
WET LOCKERA tower or compartment
maintained for hanging parachutes that are damp
or have been immersed in water.
WHIPSTITCHA stitch used to join two
piece of webbing and to reinforce weak seams.
WHISKERA thread filament protruding
YOKE AND PLATE ASSEMBLYThe
removable end of connector link.