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 | 7-184. Assembling and Securing Clip-Locking Turnbuckles
9/8/98
AC 43.13-1B
the shank four times, binding the wrapping
wires in place as shown in figure 7-27.
a. When a swaged terminal is being se-
cured, one wire is passed through the hole in
the terminal and is looped over the free end of
the other wire and both ends wrapped around
the shank. All lock wire used in the safetying
of turnbuckles should be carbon steel, corro-
sion-resistant steel, nickel-chromium iron alloy
(inconel), nickel-copper alloy (monel) or alu-
minum alloy. For safety cable diameter of
safety wire size and material, refer to table 7-8.
b. Care should be exercised when safety
wiring, particularly where corrosion will pres-
ent a problem, because smaller wire sizes tend
to crack when twisted.
TABLE 7-8. Turnbuckle safetying guide.
Cable
Size
1/16
3/32
1/8
Type of
Wrap
Single
Single
Single
1/8
1/8
5/32
and
greater.
5/32
and
greater
5/32
and
greater
Double
Single
Double
Single
Double
Diameter of
Safety Wire
0.040
0.040
0.040
0.040
0.057 min.
0.040
0.057 min.
0.0512
Material (An-
nealed
Condition)
Copper, brass.1
Copper, brass.1
Stainless steel,
Monel and
“K” Monel.
Copper, brass.1
Copper, brass.1
Stainless steel,
Monel and
“K” Monel.1
Stainless steel,
Monel or
“K” Monel.1
Copper, brass.
1Galvanized or tinned steel, or soft iron wires are also accept-
able.
7-183. SPECIAL LOCKING DEVICES.
Several turnbuckle locking devices are avail-
able for securing turnbuckle barrels such as
wire-locking clips. Persons intending to use a
special device must ensure the turnbuckle as-
sembly has been designed to accommodate
such devices. A typical unit is shown in fig-
ure 7-28. When special locking devices are
not readily available, the use of safety wire is
acceptable.
7-184. ASSEMBLING AND SECURING
CLIP-LOCKING TURNBUCKLES. (See
table 7-9 and figure 7-29.) Wire clip-locking
turnbuckles are assembled and secured in the
following ways.
a. Engage threads of turnbuckle barrel
with threads of cable terminal and turn barrel
until proper cable tension is reached.
b. Align slot in barrel with slot in cable
terminal.
c. Hold lock clip between thumb and
forefinger at loop end and insert straight end of
clip into opening formed by aligned slots.
d. Bring hook end of lock clip over hole
in center of turnbuckle barrel and seat hook
loop into hole.
e. Apply pressure to hook shoulder to en-
gage hook lip in turnbuckle barrel and to com-
plete safety locking of one end of turnbuckle.
NOTE: Repeat the above steps to
safety lock the opposite end of turn-
buckle. Both lock clips may be in-
serted in the same turnbuckle barrel
hole or they may be inserted in oppo-
site holes. However, do not reverse
wire locking clips
Par 7-182
Page 7-45