Safety Wiring, The Mechanics Signature

A couple of tools that always seemed to be in the hands of a helicopter mechanic were safety wire pliers and “dikes”.  The “dikes” were a diagonal, side cutting, wire cutter.  The safety wire pliers had narrowed jaws that could be locked down on a couple ends of .032 diameter stainless steel wire. In the center, between the pliers handles, was a jackscrew that acted like a “Yankee Screwdriver”.  When you pulled on the knurled knob on the end, it twisted the pliers and in turn twisted the two wires together in a very consistent single wire unit.  When this wire was placed correctly between two bolts that had a their heads drilled to accept the wire through them, it would keep each bolt from turning and loosening up.  If one bolt tried to loosen, it would actually tighten the bolt it was wired to.  The jaws were also angled so you could grab a loose end of twisted wire on a bolt and snap it loose with a quarter roll of the wrist Safety wiring is a very important concept for a piece of machinery that relies on all parts staying together in flight while it tries to vibrate itself to death.  The safety wire pliers had a wire cutting area behind the jaws, but we usually used the “dikes” because they had a plastic insert between the cutting jaws.  This insert would clamp down around the cut ends of wire and kept them from flying across the flight line.  I have never seen a pair like them since leaving the service, although the safety wire pliers are readily available.  It was definitely a safety plus to use the “dikes” when working in close proximity with other maintenance personnel.  Those flying snips of wire could put an eye out in an instant.  There were also many areas such as behind the instrument panel and inside your radio and navigational equipment that could be arced out with an errant piece of safety wire.  It was also a courtesy to take the short end remaining on the last bolt head and curl it around so the end wasn't positioned to puncture an unsuspecting hand or finger.  It was terrible to run one of these ends into the end of your index finger, but even worse to realize it and have to pull that twisted wire out of the finger.  Most all the aircraft mechanics I have known have hands that are always cut up.  They also had calluses on the edges of each index finger at the first knuckle on the thumb side from hand twisting wire.

You could tell a lot about the maintenance done on an aircraft by looking at the care and consistency of the safety wiring. It was the signature of the mechanic.

Submitted by:
    Warren R. Smith, former Cpl. USMC

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