An impact absorber device (10) of a fixed landing skid of an aircraft (1) is described. The device comprises a female element (20), a male element (30) and a core (40) arranged between said female element and said male element, wherein said female element comprises a cavity and said male element comprises a support and pressure surface for supporting said core, wherein said core comprises a body with controlled plastic deformation of a metallic material. In embodiments of the invention, the core comprises an extruded body having a honeycomb structure or a body comprising a spirally wound metallic substrate.