Engine Overhaul Manual
Jabiru Aircraft
Pty Ltd
Jabiru 2200 & 3300 Aircraft Engines
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ISSUE
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Dated : 28/10/2014
Issued By: AS
Page: 38 of 201
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3.9 Safety Wire
Only stainless steel safety wire is used on the Jabiru Aircraft Engine.
There are two methods of safety wiring; the double-twist method that is most commonly used, and
the single-wire method used on screws, bolts, and/or nuts in a closely-spaced or closed-geometrical
pattern such as a triangle, square, rectangle, or circle. The single-wire method may also be used on
parts in electrical systems and in places that are difficult to reach.
When using double-twist method of safety wiring, 0.032 inch minimum diameter wire should be used
on parts that have a hole diameter larger than 0.045 inch (1.1mm). When using the single-wire
method, the largest size wire that the hole will accommodate should be used.
WARNING
Care must be taken not to confuse steel with Aluminium wire.
There are many combinations of safety wiring with certain basic rules common to all applications.
These rules are as follows.
a. When bolts, screws, or other parts are closely grouped, it is more convenient to safety wire them
in series. The number of bolts, nuts, screws, etc., that may be wired together depends on the
application.
b. Drilled boltheads and screws need not be safety wired if installed with self-locking nuts.
c. To prevent failure due to rubbing or vibration, safety wire must be tight after installation.
d. Safety wire must be installed in a manner that will prevent the tendency of the part to loosen.
e. Safety wire must never be over-stressed. Safety wire will break under vibrations if twisted too
tightly. Safety wire must be pulled taut when being twisted, and maintain a light tension when
secured (Figure 43).
f. Safety-wire ends must be bent under and inward toward the part to avoid sharp or projecting
ends, which might present a safety hazard.
g. Safety wire inside a duct or tube must not cross over or obstruct a flow passage when an
alternate routing can be used.
h. Check the units to be safety wired to make sure that they have been correctly torqued, and that
the wiring holes are properly aligned to each other. When there are two or more units, it is
desirable that the holes in the units be aligned to each other. Never over-torque or loosen to
obtain proper alignment of the holes. It should be possible to align the wiring holes when the
bolts are torqued within the specified limits. However, if it is impossible to obtain a proper
alignment of the holes without under-torquing or over-torquing, try another bolt which will permit
proper alignment within the specified torque limits.
i. To prevent mutilation of the twisted section of wire, when using pliers, grasp the wires at the
ends. Safety wire must not be nicked, kinked, or mutilated. Never twist the wire ends off with
pliers; and, when cutting off ends, leave at least four to six complete turns (1/2 to 5/8 inch long)
after the loop. When removing safety wire, never twist the wire off with pliers. Cut the safety wire
close to the hole, exercising caution.
j. Install safety wire where practicable with the wire positioned around the head of the bolt, screw,
or nut, and twisted in such a manner that the loop of the wire fits closely to the contour of the
unit being safety wired.
When using a wire twister (safety wire pliers), grip the wire in the jaws of the wire twister and slide
the outer sleeve down with your thumb to lock the handles or lock the spring-loaded pin.
Pull the knob, and the spiral rod spins and twists the wire.
Squeeze handles together to release wire.
WARNING
When using wire twisters, and the wire extends 3 inches beyond the jaws of the twisters, loosely
wrap the wire around the pliers to prevent whipping and possible personal injury. Excessive
twisting of the wire will weaken the wire.
