Which cable type is commonly used in primary control systems where operation over pulleys is frequent?

The correct choice reflects a misunderstanding of common cable types used in primary control systems. In the context of this question, when considering primary control systems that frequently operate over pulleys, it’s important to focus on cable diameters that provide the necessary balance of strength, flexibility, and resistance to wear.

Typically, smaller diameters like 1/8 inch and 3/16 inch cables are more appropriate for such applications because they are often easier to route over pulleys and will not add unnecessary weight to the control system. These smaller cables also provide the required flexibility to navigate around pulleys without being excessively rigid.

In contrast, a diameter of 3/4 inch is generally too large for typical control systems where frequent pulley operations are common, as it would be more suited for applications requiring heavy lifting or structural support rather than delicate control mechanisms.

Understanding these specifications is crucial in ensuring that the selected cable not only meets operational demands but also enhances the overall efficacy and reliability of the control systems in aviation.