Movement about the longitudinal axis (roll) in a helicopter is affected by which control?

Movement about the longitudinal axis, commonly referred to as roll, in a helicopter is primarily affected by cyclic pitch control. The cyclic pitch control allows the pilot to change the pitch of the rotor blades as they rotate around the mast, leading to a differential lift on either side of the helicopter. When the pilot tilts the cyclic forward, backward, or to the sides, it alters the angle of attack of the blades in a specific manner, causing one side to generate more lift than the other. This difference in lift results in a rolling motion of the helicopter on its longitudinal axis.

In contrast, collective pitch control primarily adjusts the pitch angle of all rotor blades collectively, which affects vertical climb or descent rather than roll. Rudder control is used to manage yaw movements, helping the helicopter turn left or right. Throttle control regulates engine power and rotor speed but does not directly influence the helicopter's roll motion. Understanding the role of cyclic pitch control in producing roll is crucial for effective helicopter maneuverability and stability.