Method of Constructing a Vertical Profile in the Event of Depressurization in an Area with Risks and Associated Devices

Method of generating a flight plan portion that is secured in case of depressurization corresponding to a depressurization descent profile in the presence of obstacles, an original flight plan being defined, wherein it comprises:

• a step of defining a first point of the flight plan, called non-return point, denoted NRP, and a second point of the flight plan, called EOZ, the two points delimiting a portion of the flight plan plotted above an area identified as “with risks”;
• a step of determining a first flight plan portion comprising the definition of a lateral offset angle from the original flight plan and the definition of a distance to be traveled on said offset branch, the initial point of the first portion necessarily being situated between the non-return point NRP and the second point EOZ;
• a step of determining a vertical descent profile comprising the vertical part of the first flight plan portion and the vertical part of a second flight plan portion, a set of safety altitudes defining a set of levels and of waypoints for the aircraft on the two flight plan portions, the last level allowing the crew and the passengers to breathe freely without the need for additional oxygen.