Cables, used in aircraft control systems, comply with a number of British and American Standards and are ‘preformed’ during manufacture. Preforming is a process in which each strand is formed into the shape that it will take up in the completed cable. This makes the cable more flexible, easier to splice and less prone to kinking. Another advantage of preformed cables is that, in the event of a wire breaking, it will lie flat within its strand, so that the cable should be less likely to jam in its pulleys and fairleads.
Preformed cables are manufactured from either galvanised carbon steel or corrosion-resistant steel and are impregnated with friction-preventive lubricant during manufacture. Non-preformed single strand cable may be found on some minor aircraft systems. Aircraft cables are usually classified by either their minimum breaking load or nominal diameter.
It is very rare for a cable to be manufactured by an operator. They are normally ordered through the aircraft’s IPC and the aircraft manufacturer supplies the cable fully formed with the necessary end-fittings and to the correct load factor.