The inventive flight control assisting device comprises first means (4) for determining the actual aircraft flight conditions, second means (5) for determining, with the aid of said actual flight conditions and a predetermined pattern, a minimum approaching distance corresponding to a minimum distance between projections on the horizontal plane of the aircraft actual position and a touch-down point when said aircraft moves downwards and decelerates according to an optimised approach in such a way that stabilised approaching conditions are attained, and display means (7) for displaying at least said minimum approaching distance on a navigation screen (9) in the form of a first circular arc focused on a position relative to the aircraft which displays the touch-down position.