Method and device for revising a flight plan of an aircraft

The method involves determining an auxiliary flight plan corresponding to a lateral revision of a current flight plan on a low altitude flight section. A decision point indicating last position of an aircraft along the current flight plan is automatically determined. A pilot activates the auxiliary plan according to automatic presentation of the point on a head up display (11), for performing lateral revision of the current plan. Independent claims are also included for the following: (A) a device for performing a lateral revision of a current flight plan of an aircraft; and (B) an aircraft comprising an automatic guiding system with a device performing lateral revision.