Abstract: The tricopter type rotary-wing drone includes three arms connected to a frame. Each of the free ends of the arms support a rotor with an axis perpendicular to the respective free end. The rotor is driven in rotation by a motor connected to power supply. The arms are pivotally mounted on the frame. Two arms automatically drive the rotor supported by their respective free ends into a position in which its axis forms an angle between ?30° and +150° with the plane of the frame. The third arm automatically pivots, if necessary, into a position in which its free end is spaced apart from the apex being considered of the triangle by an angle between ?60° and +60°.