Patent ID: 8078345

Claim:
A method of automatic control of an emergency descent of an aircraft, according to which method, when an automatic emergency descent function is engaged, the following successive operations are carried out: a) determining automatically a set of vertical directives, said directives comprising: a target altitude which represents an altitude to be attained by the aircraft at the end of the emergency descent; and a target speed which represents a speed that the aircraft must comply with during the emergency descent; b) determining automatically a set of lateral directives, which represents a lateral maneuver to be carried out during the emergency descent; and c) guiding the aircraft automatically so that it complies simultaneously with said set of vertical directives and said set of lateral directives until it attains said target altitude which it thereafter maintains, said automatic guidance possibly being interrupted by an action of a pilot of the aircraft, according to which method, to automatically engage said emergency descent function, the following operations are carried out in an automatic manner: α1) determining a variation in altitude of the cabin of the aircraft, which depends on a variation in the pressure measured inside the cabin; β1) determining an engagement criterion which depends on said variation in altitude of the cabin; γ1) comparing this engagement criterion with a predetermined threshold value; and δ1) engaging said emergency descent function when said engagement criterion is above said threshold value, wherein: in step δ1), said emergency descent function is engaged when said engagement criterion is above said threshold value for a predetermined duration, and in step a), the following operations are moreover carried out in an automatic manner: in a step α2): a variation in the pressure of the air in the cabin is monitored; and the size of a hole in the structure of the aircraft, corresponding to structural damage, is estimated as a function of said variation in the pressure of the air in the cabin; and in a step β2), said target speed is adapted to said estimated size of the hole in the structure of the aircraft.