Final answer:
Control cable wire breakage commonly occurs at areas of concentrated stress, primarily where cables pass over pulleys and through fairleads due to bending, or at swaged fittings like turnbuckle and ball terminals due to fatigue.
Step-by-step explanation:
The breakage of control cable wires frequently occurs at specific points where stress is concentrated. This is typically not at random points along the length of a cable but rather at locations where the cable is subject to repeated stress or potential abrasion. Among the options provided, breakage usually occurs where cables pass over pulleys and through fairleads. These locations are where the cables bend, which adds stress and can lead to the development of fatigue and eventual failure of the wire strands. Additionally, the swaged fittings, such as turnbuckle and ball terminals, are also common points of failure due to the stress exerted on the wire at the termination points. As metal fatigue sets in, these wires can fracture with repeated loading and unloading cycles, making these areas more susceptible to breakage over time.