Many people see safety wire used on airplanes, and thus think that it must be the best way to prevent fasteners from loosening. Not so. Here is what a bunch of literature says:
Fastener Design Manual; NASA Reference Publication 1228
Although lockwiring is a laborious method of preventing bolt or nut rotation, it is still used in critical applications, particularly in the aerospace field.
Acceptable Methods, Techniques and Practices û Aircraft Inspection and Repair; FAA Advisory Circular AC43.13-1B
These practices
are not a means of obtaining or maintaining
torque, rather a safety device to prevent the
disengagement of screws, nuts, bolts, snap
rings, oil caps, drain cocks, valves, and parts.
Bickford, John H., 1981 An Introduction to the design and behavior of bolted joints
The primary purpose of safety wiring is to prevent complete loss of a fastener. It's not particularly effective in preventing minor relative nut and bolt rotation and subsequent loss of preload.
It's effective in preventing complete loss of the fastener. It is, however, an ineffective
method for preventing loss of preload; some rotation can still occur, even with the best of tying techniques.
Safety wire may be used to replace previous existing safety wire. If loose or broken wires or
loose fasteners are found at disassembly, however, self-locking fasteners may be installed at reassembly
Verein Deutscher Ingenieure, Systematic Calculation of High Duty Bolted Joints. Joints with One Cylindrical Bolt VDI 2230, Part 1
