Abstract: The invention relates to an amphibian aircraft incorporating a hydrodynamic system formed by three floats wherein the first two floats are attached to a fuselage leading portion symmetrically to the aircraft axis and the third float is attached to a fuselage trailing portion along the aircraft axis of symmetry. The distance between the floats renders it possible to place a trailing float out of the zones of the water surface disturbed by hydroplaning leading floats. Moreover, the center of gravity is shifted behind the steps of the bottom of the leading floats to the trailing portion of the fuselage.