This MCP/FCU interface (30) for control of the automatic pilot (13) and/or flight director (14) is provided with an access port linked to the ATN terminal (2) by a digital information transmission link (4) and furnished with display device displaying the trajectory modification orders originating from the air traffic control authorities and with enabling device imposing on the automatic pilot (13) and/or flight director (14) the operating mode and the directives corresponding to a trajectory modification order having formed the subject of an acceptance by the pilot.