What Makes Helicopters Fly?
A helicopter is lifted into the air by the same principle through which an airplane takes off from the ground: the movement of an airfoil through air. The wing of an airplane is an airfoil, which is moved through the air with the forward movement of the entire aircraft. The rotor blades of a helicopter are also airfoils, which are moved through the air in a circular motion without requiring any movement of the helicopter itself. As air flows over an airfoil, a pressure differential is created. The pressure on the top surface of the airfoil is less than the pressure exerted on the bottom, due to higher speed of the airflow over the top. This results in a lifting force. When the lift created exceeds the weight of the aircraft, flight is achieved. The main rotor of a helicopter is controlled by the “cyclic,” a control held in the pilot’s right hand. Using the cyclic, the pilot is able to tilt the main rotor in any direction he or she wants the helicopter to fly. Tilting the main rotor con
