1. A method for managing the flight of an aircraft (10) in a visual approach phase
to a runway (22), the method being implemented by an electronic flight management system
(20) and comprising the following steps:
- acquiring (120) at least one set among a set of values of lateral visual approach
trajectory parameters and a set of values of vertical visual approach trajectory parameters,
at least one of said values of visual approach trajectory parameters being able to be designated by a user,
- computing (130) at least one trajectory among a lateral visual approach trajectory (30) from the values of said lateral visual approach trajectory parameters and a vertical visual approach trajectory (32) from the values of said vertical visual approach trajectory parameters, and
- generating (140) a visual approach trajectory to the runway (22) from the lateral visual approach trajectory (30) and/or the vertical visual approach trajectory (32).

2. The method according to claim 1, wherein the method further comprises a step (170) for displaying, on a display screen (16), the visual approach trajectory.
3. The method according to claim 2, wherein the display step (170) further comprises the display of a symbol representative of the position of the aircraft (10) relative to the visual approach trajectory.
4. The method according to any one of the preceding claims, wherein the method further comprises a step (180) for transmitting instructions for following the visual approach trajectory to an electronic automatic pilot system.
5. The method according to any one of the preceding claims, wherein each lateral visual approach trajectory parameter is chosen from among the group consisting of: the position of an initial point (A) of the approach trajectory, an outbound heading (TRK), a length (L) of a segment of the approach trajectory, a turn radius (D) of the aircraft (10) and a turning direction of the aircraft (10); and
each vertical visual approach trajectory parameter is selected from among the group consisting of: a minimum altitude (MA) of an initial point of descent (X3) along a final approach axis (APP) and an angle (FP) of the final approach axis (APP) relative to a reference plane (P) of the runway (22).

z6. The method according to any one of the preceding claims, wherein the method
further comprises, prior to the acquisition step (120), a step (100) for selecting a type among
a group of types (T1, T2, T3) of visual approach trajectory, each type (T1, T2, T3) of visual
approach trajectory corresponding to a respective predefined form of the visual approach
trajectory, and
during the acquisition step (120), the or each set of values of visual approach trajectory parameters then depending on the selected type (T1, T2, T3).
7. The method according to claim 6, wherein the group of types (T1, T2, T3)
comprises:
+ a first type (T1) corresponding to a visual approach trajectory comprising a deviation by an outbound heading (TRK) followed by a segment substantially parallel to the runway (22) and a turn at substantially 180°;
+ a second type (T2) corresponding to a visual approach trajectory comprising a deviation by an outbound heading (TRK) followed by a segment substantially perpendicular to the runway (22) and a turn at substantially 90°; and
+ a third type (T3) corresponding to a visual approach trajectory comprising a deviation by an outbound heading (TRK) followed by a turn substantially between 90° and 180°, a segment substantially parallel to the runway (22) and a turn at substantially 180°.
8. The method according to any one of the preceding claims, wherein the method further comprises a step (160) for determining a maneuvering zone around the runway (22).
9. The method according to any one of the preceding claims, wherein the method further comprises a step (150) for estimating at least one aeronautical variable at least at one point of the visual approach trajectory.
10. The method according to claim 9, wherein each aeronautical variable at a respective point of the visual approach trajectory is chosen from among the group consisting of: a distance between said respective point of the visual approach trajectory and another point of the visual approach trajectory, a remaining quantity of fuel, a passage date and a speed of the aircraft (10).

11. A computer-readable medium including a computer program comprising software instructions which, when executed by a computer, carry out a method according to any one of the preceding claims.
12. An electronic flight management system (20), the system (20) being configured to manage the flight of an aircraft (10) in the visual approach phase to a runway (22), and comprising:

- an acquisition module (24) configured to acquire at least one set among a set of values of lateral visual approach trajectory parameters and a set of values of vertical visual approach trajectory parameters,
- a designating module (26) configured to designate, from an interaction with a user, at least one of said values of visual approach trajectory parameters,
- a computing module (28) configured to compute at least one trajectory among a lateral visual approach trajectory (30) from the values of said lateral visual approach trajectory parameters and a vertical visual approach trajectory (32) from the values of said vertical visual approach trajectory parameters, and
- a generating module (34) configured to generate a visual approach trajectory to the runway (22) from the lateral visual approach trajectory (30) and/or the vertical visual approach trajectory (32).

13. The system (20) according to claim 12, wherein the system (20) further comprises a display module (36) configured to display, on a display screen (16), the visual approach trajectory.
14. The system (20) according to claim 13, wherein the display module (36) is further configured to display a symbol representative of the position of the aircraft (10) relative to the visual approach trajectory.