Abstract: A device for repairing defects in an internal layer of a structure, for example, an aircraft. The device includes a cylindrical body which rotates around its axial direction, a movement conversion device housed in the cylindrical body and assembled such that it is able to move in the axial direction, a configuration device able to cause the displacement of the conversion device by an axial traveling motion, and a cutting element coupled to the cylindrical body and to the conversion device such that the cutting element is able to be made to rotate by the cylindrical body and to be made to move with a radial displacement by the conversion device between a folded position and a deployed position through an opening defined in the cylindrical body in order to machine the internal layer with a cut which depends on the axial displacement of the conversion device.