Tecnam P2002 JF - Page 264

Page 203 2
nd
Edition – Rev 0
02-40
SAFETYING – MAINTENANCE PRACTICES
There are many combinations of safety wiring with certain basic rules common to all
applications. These rules are as follows.
 Remove all pieces of the old lockwire from the component
 Use only new lockwire, never use lockwire more than once or damaged
 Do not drill additional safety wire holes
 When bolts, screws, or other parts are closely grouped, it is more convenient to safety
wire them in series.
 Drilled boltheads and screws need not be safety wired if installed with self-locking nuts.
 Safety wire must never be overstressed. 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. (See Figure 3.)
 Safety-wire ends must be bent under and inward toward the part to avoid sharp or
projecting ends, which might present a safety hazard.
 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
Overtorque 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 undertorquing or
overtorquing, try another bolt which will permit proper alignment within the specified
torque limits.
 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.
 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 securing caps and drain cocks, the safety wire should be anchored to an adjacent
fillister-head screw (see Figure below). This method of safety wiring is applied to
wingnuts, filler plugs, single-drilled head bolts, fillister-head screws, etc.; which are
safety wired individually.