Which type of linkage is used to manually control the primary flight controls?

• A. Mechanical
• B. Direct
• C. Hydraulic
• D. Electrical

Answer: (A)

Manual control of the primary flight controls uses a mechanical linkage—the network of cables, push-pull rods, pulleys, and bellcranks that connect the pilot’s controls to the control surfaces. This creates a direct physical path so input from the pilot is transmitted straight to the ailerons, elevator, and rudder, giving immediate, tangible control forces and feedback.

Hydraulic or electrical systems move surfaces using power sources and actuators, so they’re not manual control even though a pilot’s input starts the process. The term “direct” isn’t the standard way to describe this physical connection, whereas “mechanical linkage” precisely conveys the manual, cable-and-rod path from control to surface.