What are the most likely places for a control cable to wear or break?

• A. Over the rudder control pulleys
• B. Where the cables pass over pulleys or through fairleads
• C. At the cockpit light switches
• D. Where cables are sealed in metal conduit

Answer: (B)

The main idea is that control cables wear most where they bend or rub as they route through the aircraft. When a cable passes over pulleys or through fairleads, it repeatedly changes direction and slides against the pulley groove or guide surface. This friction and bending stress causes the outer strands to fray and the core to fatigue over time, making those areas the most common failure points. So the best choice points to the places where the cable actually changes direction and makes contact with guides—the pulleys and fairleads. The other options don’t fit because a cockpit light switch is electrical, not a loading path for the cable; a single rudder pulley is only one potential site and not as generally prone as all the bend/guide points; and being inside metal conduit protects the cable, reducing wear there compared with exposed bends and guides. Regularly inspect each pulley and fairlead for signs of wear, fraying, or roughness to catch issues early.