Which control surface is associated with longitudinal movement?

The control surface that is associated with longitudinal movement is the elevators. Elevators are located on the tail of an aircraft and are responsible for controlling pitch, which is the movement of the aircraft around its lateral axis. This allows the aircraft to ascend or descend during flight, effectively managing its long-axis stability and control.

In contrast, the rudder is primarily involved in controlling yaw, which is the movement around the vertical axis. Ailerons are used to manage roll, which involves tilting the aircraft from side to side around its longitudinal axis. Flaps are used to increase lift during takeoff and landing but do not directly manage the longitudinal movement of the aircraft. Thus, elevators are the definitive control surface for managing an aircraft's pitch and, by extension, its longitudinal movement.