A single-axis autopilot typically operates which control surface?

A single-axis autopilot typically operates the ailerons. This type of autopilot is primarily designed to control the aircraft's roll by adjusting the ailerons, which are situated on the wings. The function of the ailerons is crucial for maintaining lateral stability and control during flight.

The ailerons work by altering the lift produced by each wing, allowing the aircraft to bank left or right. This roll control is essential, especially in maintaining a straight and level flight path as well as in executing turns. A single-axis autopilot doesn't engage with other control surfaces, like the elevator for pitch (which would be managed by a two-axis autopilot) or the rudder for yaw, focusing solely on the roll axis to enhance stability and reduce pilot workload during flight. Therefore, the operation of ailerons makes the single-axis autopilot particularly effective for maintaining lateral control.