Movement about the lateral axis (pitch) in a helicopter is affected by which control?

Movement about the lateral axis, commonly referred to as pitch, in a helicopter is primarily controlled by cyclic pitch control. This control allows the pilot to adjust the pitch of the rotor blades as they rotate, changing the lift produced by each blade at various points in their rotation. By tilting the rotor disk forward or backward through the cyclic control, the helicopter can ascend or descend, or even change its forward or backward flight direction, effectively controlling the pitch of the aircraft.

The collective pitch control adjusts the overall pitch angle of all the rotor blades simultaneously, mainly influencing the vertical movement (altitude) of the helicopter rather than its pitch movement around the lateral axis. The rudder control is responsible for yaw movement, which involves turning the helicopter left or right around its vertical axis. Throttle control primarily affects engine power and rotor RPM but does not directly influence pitch movement.

Therefore, cyclic pitch control is the correct choice as it directly governs pitch movement by varying lift throughout the rotor cycle, allowing the pilot to achieve controlled pitch changes.