FAA Advisory Circular 43.13-1B
Acceptable Methods, Techniques, and Practices
Aircraft Inspection and Repair
AC 43.13-1B | 7. Aircraft Hardware, Control Cables, and Turnbuckles | 8. Inspection and Repair of Control Cables and Turnbuckles | 7-141. Cable Definitions
9/8/98
AC 43.13-1B
SECTION 8. INSPECTION AND REPAIR OF CONTROL CABLES
AND TURNBUCKLES
7-140. GENERAL. Aircraft control cables
are generally fabricated from carbon steel or
corrosion-resistant steel wire of either flexible
or nonflexible-type construction.
7-141. CABLE DEFINITIONS. The fol
lowing cable components are defined in accor
dance with Military Specifications
MIL-W-83420,
MIL-C-18375,
and
MIL-W-87161.
a. Wire Center. The center of all strands
shall be an individual wire and shall be desig
nated as a wire center.
b. Strand Center or Core. A strand cen
ter is a single, straight strand made of pre
formed wires, similar to the other strands
comprising the cable, in arrangement and
number of wires.
c. Independent Wire Rope Center
(IWRC) 7 by 7. A 7 by 7 independent wire
rope center as specified herein shall consist of
a cable or wire rope of six strands of seven
wires each, twisted or laid around a strand
center or core consisting of seven wires.
7-142. FLEXIBLE CABLES. Flexible,
preformed, carbon steel, Type I, composition A
cables, MIL-W-83420, are manufactured from
steel made by the acid-open-hearth, basic-open
hearth, or electric-furnace process. The wire
used is coated with pure tin or zinc. Flexible,
preformed, corrosion-resistant, Type I, compo
sition B cables, MIL-W-87161,
MIL-W-83420, and MIL-C-18375 are manu
factured from steel made by the electric-
furnace process. (See table 7-3 and fig
ure 7-8.) These cables are of the 3 by 7,
7 by 7, 7 by 19, or 6 by 19 IWRC construction,
according to the diameter as specified in ta
ble 7-3. The 3 by 7 cable consists of three
strands of seven wires each. There is no core
in this construction. The 3 by 7 cable has a
length of lay of not more than eight times or
less than five times the nominal cable diame
ter. The 7 by 7 cable consists of six strands, of
seven wires each, laid around a center strand
of seven wires. The wires are laid so as to de
velop a cable which has the greatest bending
and wearing properties. The 7 by 7 cable has a
length of lay of not more than eight times or
less than six times the cable diameter. The
7 by 19 cable consists of six strands laid
around a center strand in a clockwise direction.
The wires composing the seven individual
strands are laid around a center wire in two
layers. The center core strand consists of a lay
of six wires laid around the central wire in a
clockwise direction and a layer of 12 wires laid
around this in a clockwise direction. The six
outer strands of the cable consist of a layer of
six wires laid around the center wire in a
counterclockwise direction and a layer of
12 wires laid around this in a counterclockwise
direction. The 6 by 19 cable consists of six
strands of 19 wires each, laid around a 7 by 7.
MIL-C-18375 cable, although not as strong as
MIL-W-83420, is equal in corrosion resistance
and superior in non-magnetic and coefficient
of thermal expansion properties.
7-143. NYLON-COATED CABLES.
a. Nylon-coated cable is made by ex
truding a flexible nylon coating over corro
sion-resistant steel (CRES) cable. The bare
CRES cable must conform and be qualified to
MIL-W-83420. After coating, the jacketed ca
ble must still conform to MIL-W-83420.
b. The service life of nylon-coated cable
is much greater than the service life of the
same cable when used bare. Most cable wear
occurs at pulleys where the cable bends. Wear
Par 7-140
Page 7-27