Impact resistant dorsal fin structure of an aircraft being extended along a longitudinal direction X-X' and being symmetric relative to a vertical plane P including the longitudinal direction X-X', the plane P provides two sides A, B on each side of the vertical plane P in the dorsal fin , said dorsal fin is adapted to be arranged on a fuselage of the aircraft and comprises, an upper support at the upper end of the dorsal fin , the upper support comprising a sliding surface (3.1), a ballistic material layer for absorbing high energy impacts, the ballistic material layer comprising a first side (4.1) intended for receiving impacts, said first side (4.1) being arranged on the side A, a second side (4.2) intended for receiving impacts, said second side (4.2) being arranged on the side B and being opposite to the first side (4.1) with respect to the plane P, and an internal surface (4.3) faced to the interior of the dorsal fin ; a front frame comprising a substantially planar front edge (5.1), and a rear frame comprising a substantially planar rear edge (6.1), wherein the front frame and rear frame support the ballistic material layer and the upper support , the first side (4.1) of the ballistic material layer comprises a first connecting line , and the opposite side (4.2) comprises a second connecting line , in such a way that the ballistic material layer is adapted to be joined to the fuselage of the aircraft by such connecting lines , and the internal surface (4.3) of the ballistic material is in contact with the sliding surface (3.1) of the upper support , and said ballistic material layer is arranged in a sliding manner around the sliding surface (3.1) of the upper support . an upper support at the upper end of the dorsal fin , the upper support comprising a sliding surface (3.1), a ballistic material layer for absorbing high energy impacts, the ballistic material layer comprising a first side (4.1) intended for receiving impacts, said first side (4.1) being arranged on the side A, a second side (4.2) intended for receiving impacts, said second side (4.2) being arranged on the side B and being opposite to the first side (4.1) with respect to the plane P, and an internal surface (4.3) faced to the interior of the dorsal fin ; a first side (4.1) intended for receiving impacts, said first side (4.1) being arranged on the side A, a second side (4.2) intended for receiving impacts, said second side (4.2) being arranged on the side B and being opposite to the first side (4.1) with respect to the plane P, and an internal surface (4.3) faced to the interior of the dorsal fin ; a front frame comprising a substantially planar front edge (5.1), and a rear frame comprising a substantially planar rear edge (6.1), the front frame and rear frame support the ballistic material layer and the upper support , the first side (4.1) of the ballistic material layer comprises a first connecting line , and the opposite side (4.2) comprises a second connecting line , in such a way that the ballistic material layer is adapted to be joined to the fuselage of the aircraft by such connecting lines , and the internal surface (4.3) of the ballistic material is in contact with the sliding surface (3.1) of the upper support , and said ballistic material layer is arranged in a sliding manner around the sliding surface (3.1) of the upper support . <EOS>