A method for managing a symbology in an on-board viewing system for an aircraft, the graphical representation comprising the piloting and navigation symbology overlaid on a representation of the exterior landscape, the symbology comprises a first angular attitude scale comprising a first symbol called an aircraft mockup, a second speed scale, a third altitude scale and a second symbol called the speed vector. When the angular lateral distance between the position of the first symbol and the position of the second symbol is such that the second symbol is not overlaid on the lateral scales, the various scales are represented in the nominal position; when the angular lateral distance between the position of the first symbol and the position of the second symbol is such that the second symbol is overlaid on one of the scales, the various scales move and/or their size decreases.