What is the primary function of the main rotor in a rotary wing aircraft?

The primary function of the main rotor in a rotary wing aircraft is to generate lift. Lift is the force that opposes the weight of the aircraft and allows it to rise off the ground. In rotary wing aircraft, the main rotor system consists of blades that rotate around a central hub and create differences in air pressure above and below the blades. This pressure differential produces lift, enabling the aircraft to ascend, hover, or maneuver in flight.

While thrust is a factor in a helicopter's operation, it is more closely associated with the propulsion that moves the aircraft forward or backward, which is primarily generated by the main rotor's blades as they push air downwards. The control of yaw, which refers to rotation around the vertical axis, is managed by the tail rotor, and weight distribution is a concern for overall aircraft balance but does not relate specifically to the primary role of the main rotor. Thus, generating lift is the essential function of the main rotor in allowing the rotary wing aircraft to perform its various flight maneuvers.