of the ground and moves because of its rotors. a rotor is several small wings, called rotor blades, that spin together around a shaft. for that reason, helicopters are sometimes called "rotary-wing aircraft". a helicopter flies differently from an airplane. an airplane must move forward to stay in the air, but because the helicopter's rotor blades are always moving, the helicopter can stop and stay in one place above the ground. not needing a runway, they can land in places where an airplane cannot. helicopters can move by tilting their rotor blades, which causes the aircraft to fly in the direction the blades are tilted.