Abstract: A rotor blade for an aircraft includes first and second blade tips, a blade body, and a vortex-generating blade. The blade body has an end forming the first blade tip of the rotor blade and an airfoil section configured such that during rotation, pressure acting on a lower surface of the blade body is greater than pressure acting on an upper surface of the blade body. The vortex-generating blade is disposed at an end of the rotor blade and forms the second blade tip. The vortex-generating blade also has an airfoil section configured such that during rotation, pressure acting on a lower surface of the vortex-generating blade is smaller than pressure acting on an upper surface of the vortex-generating blade.

Abstract: A rotary-wing aircraft includes a fuselage, and an external device. The fuselage is provided with a rotary wing. The external device is mounted on the outside of the fuselage. The external device includes a mounting device, a mass variation device, and a damper. The mounting device is fixed to the fuselage and disposed so as to project in a lateral direction of the fuselage. The mass variation device is mounted on the mounting device and has mass that varies as the mass variation device is used. The damper couples the fuselage to the mounting device and supports the mounting device. The damper includes a stiffness variable mechanism configured to change stiffness of the damper in response to variation in the mass of the mass variation device.

Abstract: A rotor blade for an aircraft includes first and second blade tips, a blade body, and a vortex-generating blade. The blade body has an end forming the first blade tip of the rotor blade and an airfoil section configured such that during rotation, pressure acting on a lower surface of the blade body is greater than pressure acting on an upper surface of the blade body. The vortex-generating blade is disposed at an end of the rotor blade and forms the second blade tip. The vortex-generating blade also has an airfoil section configured such that during rotation, pressure acting on a lower surface of the vortex-generating blade is smaller than pressure acting on an upper surface of the vortex-generating blade.