Figure 1-23.--Measuring the diameter of a wire rope.
cross section. Figure 1-23 shows the proper method of
measuring the diameter of a wire rope.
Figure 1-25.--Cable damage resulting from a pulled-through
2. Lay Length. The distance, parallel to the axis
of the cable, in which a strand makes one complete turn
STRUCTURAL STEEL OR ALUMINUM.--
about that axis is known as the lay length or pitch
Visually inspect all terminals, shackles, lugs, and struc-
length. Figure 1-24 shows the lay length of a wire rope.
tural members for misalignment, wear, corrosion, de-
Wire rope cables are visually inspected for knots,
formation, loosening, slippage, fractures, open welds,
fraying, stretching, abrasions, severe corrosion, and
pitting, and gouges. Examine slides and screw adjusters
other signs of failure. Of particular importance is the
for burrs, misalignment, and ease of operation. Inspect
detection of a cable in which a kink has been pulled
sling attachment bolts and pins for elongation, wear,
through in order to straighten the cable. The resultant
deformed threads, and other signs of imminent failure.
deformation is known as a bird cage. See figure 1-25. In
CHAINS.--Chains will be visually inspected for
such a case, the sling should be discarded.
stretched links, wear, gouges, open welds, fractures,
The presence of one or more broken wires in one
kinks, knots, and corrosion. Chain attachment fittings
rope lay length or one or more broken wires near an
and adjusters will be examined for security, wear,
attached fitting is cause for replacement. If a broken
corrosion and deformation.
wire is the result of corrosion or if the cable is
excessively corroded, the cable must not be used
Lubrication, Transportation, and Storage
regardless of the number of broken wires. Replace
cables exhibiting rust and development of broken wires
in the vicinity of attached fittings. Replace wire ropes
Examine and lubricate all slings once a month in
evidencing bulges, core protrusions, or excessive
accordance with NAVAIR 17-1-114. When
reductions in rope diameter.
transporting slings, they will be carried at all times.
FABRIC OR WEBBING.--Fabric or webbing
Dragging slings over floors, runways, decks, and
straps must be visually inspected for cuts, holes, severe
obstructions can cut or severely abrade the material.
abrasions, mildew, dry rot, broken stitches, frays and
This malpractice results in an unserviceable sling.
Whenever possible, slings should be stored indoors in a
with foreign materials, such as oil, fuel, solvents,
clean, dry, well-ventilated area so as to be protected
caustic fluids, dirt, and lye. The existence of any of the
from moisture, salt atmosphere, and acids of all types.
above conditions renders the sling unserviceable.
In addition, slings constructed with nylon or other
Twists, knots, and similar distortions must be corrected
fabric materials will be stored in such a way as to
prevent contact with sharp objects, high temperatures,
and sunlight. Fabric materials deteriorate rapidly from
prolonged exposure to sunlight or excessive
heat--severely reducing strength and service life.
Where practicable, slings will be securely fastened to
overhead storage racks to prevent accidental damage.
Avoid laying slings on ash or concrete floors.
Figure 1-24.--Cable lay length.