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 | 10. Safety Methods for Turnbuckles | 7-181. Single-Wrap Method
9/8/98
AC 43.13-1B
SECTION 10. SAFETY METHODS FOR TURNBUCKLES
7-179. GENERAL. Safety all turnbuckles
with safety wire using either the double or sin-
gle-wrap method, or with any appropriately
approved special safetying device complying
with the requirements of FAA Technical Stan-
dard Order TSO-C21. The swaged and un-
swaged turnbuckle assemblies are covered by
AN standard drawings. Do not reuse safety
wire. Adjust the turnbuckle to the correct ca-
ble tension so that no more than three cable
threads are exposed on either side of the turn-
buckle barrel.
7-180. DOUBLE-WRAP METHOD. Of
the methods using safety wire for safetying
turnbuckles, the method described here is pre-
ferred, although either of the other methods
described is satisfactory. The method of dou-
ble-wrap safetying is shown in figure 7-26(A).
a. Use two separate lengths of wire. Run
one end of the wire through the hole in the bar-
rel of the turnbuckle and bend the ends of the
wire toward opposite ends of the turnbuckle.
d. Wrap the remaining length of safety
wire at least four turns around the shank and
cut it off. Repeat the procedure at the opposite
end of the turnbuckle.
e. When a swaged terminal is being
safetied, pass the ends of both wires through
the hole provided in the terminal for this pur-
pose and wrap both ends around the shank as
previously described. If the hole is not large
enough to allow passage of both wires, pass
the wire through the hole and loop it over the
free end of the other wire, and then wrap both
ends around the shank as previously described.
Another satisfactory double-wrap method is
similar to the previous method, except that the
spiraling of the wires is omitted as shown in
figure 7-26(B).
7-181. SINGLE-WRAP METHOD. The
single-wrap methods described in the follow-
ing paragraphs and as illustrated in figure 7-
26(C) and (D) are acceptable, but are not the
equal of the double-wrap methods.
b. Pass the second length of the wire into
the hole in the barrel and bend the ends along
the barrel on the side opposite the first. Spiral
the two wires in opposite directions around the
barrel to cross each other twice between the
center hole and the ends.
c. Then pass the wires at the end of the
turnbuckle in opposite directions through the
hole in the turnbuckle eyes or between the
jaws of the turnbuckle fork, as applicable,
laying one wire along the barrel and wrapping
the other at least four times around the shank
of the turnbuckle and binding the laid wires in
place before cutting the wrapped wire off.
a. Pass a single length of wire through
the cable eye or fork, or through the hole in the
swaged terminal at either end of the turnbuckle
assembly. Spiral each of the wire ends in op-
posite directions around the first half of the
turnbuckle barrel, so as to cross each other
twice. Thread both wire ends through the hole
in the middle of the barrel so that the third
crossing of wire ends is in the hole, again, spi-
ral the two wire ends in opposite directions
around the remaining half of the turnbuckle,
crossing them twice. Then, pass one wire end
through the cable eye or fork, or through the
hole in the swaged terminals, in the manner
previously described. Wrap both wire ends
around the shank for at least four turns each,
cutting off excess wire. This method is shown
in figure 7-26(C).
Par 7-179
Page 7-43