What primarily creates lift in a helicopter?

The primary factor that creates lift in a helicopter is the airflow as it passes around an airfoil, which refers to the rotor blades in this context. When the rotor blades spin, they are designed with a specific shape, known as an airfoil, that generates lift through the differences in air pressure above and below the blades. As air flows over the curved surface of the blades, the pressure decreases on the upper surface and increases on the lower surface, resulting in a net upward force.

This aerodynamic principle is fundamental in aviation, describing how lift is generated when moving air interacts with the rotor blades. The angle of attack, the speed of the rotor blades, and the design of the airfoil are all critical in optimizing this lift generation process. While engine power provides the necessary torque to spin the rotors, it is the shape and motion of the airfoil that actually allows the helicopter to overcome gravity and ascend.

Understanding this principle is essential for comprehending how helicopters achieve vertical flight and maneuver in the air, making it an integral aspect of rotorcraft aerodynamics.