What three mechanical methods can actuate flight control systems?

The answer identifies three mechanical methods that are commonly used to actuate flight control systems in aircraft: cables, push-pull rods, and torque tubes.

Cables are widely utilized in control systems to transmit forces from the pilot's controls to various control surfaces. They provide a lightweight and flexible means to connect components, making them ideal for applications where direct mechanical linkages are impractical.

Push-pull rods are another effective method, often used in situations where a more rigid connection is required. These rods can transmit forces in both tension and compression, providing precise control over the movement of flight control surfaces.

Torque tubes serve as a structural component that can transfer rotational motion. They are especially useful in systems where control surfaces need to be moved through a rotation, as they can effectively handle the torsional forces involved.

Together, these mechanisms form a reliable system that enables pilots to manage an aircraft's movement with precision and responsiveness. The other options provided contain methods that, while related to aircraft operation, do not primarily focus on the mechanical transmission required for standard flight control actuation.