Abstract: A method for determining a line of sight from a visor borne by a helmet fitted with a pick-up with three magnetic orthogonal coils, in relation to a mark affixed to an aircraft concretized by an emitter with three magnetic orthogonal coils, consists of initially setting up a magnetic cartography of the piloting cabin: to this end sets of measurements of fields picked up by the pick-up from fields emitted in succession by the three coils of the emitter, for different known positions and orientations of the pick-up inside the cabin, are established then entered in memory. Then the method consists of setting up, based on those measurements, a magnetic modeling of the piloting cabin. In flight, the measurement matrix, associated with a cycle of emission from the emitter, triggered when the pilot validates a line of sight in a given direction in relation to his helmet, makes it possible by using the preliminary modeling to compute accurately the orientation of that line of sight inside the mark of the aircraft.