Patent ID: 8467917

Claim:
A method for automatically managing a lateral trajectory of an aircraft upon triggering of an emergency descent, the aircraft moving along an initial lateral trajectory that is parallel or concurrent with a central axis of a protected sector of an air traffic way defining a flight plan between a departure point and a destination of the aircraft, the protected sector including a space defined between a lateral offset maxmimum on either side of the central axis, the method comprising the following steps, performed automatically after triggering the emergency descent: (1) determining a value of lateral offset that is lower than the lateral offset maximum and that is not from a full integer value of nautical miles; (2) generating an offset setpoint by using the value of lateral offset determined in step (1), the offset setpoint being defined with respect to the central axis of the protected sector and being used to form a new setpoint lateral trajectory that should be laterally followed by the aircraft during and after the emergency descent, the generating step further comprising: (2a) calculating a sum of the value of lateral offset determined in step (1) and an initial value of lateral offset defined between the central axis of the protected sector and the initial lateral trajectory; and (2b) selecting the offset setpoint by setting the offset setpoint equal to a smaller of the sum calculated in step (2a) and the lateral offset maximum; and (3) operating the aircraft to move the aircraft to the offset setpoint, generated during step (2), during the emergency descent and follow the new setpoint lateral trajectory after the emergency descent, thereby allowing the aircraft to carry out the emergency descent while remaining in the protected sector and also to maintain a trajectory substantially parallel to the central axis of the protected sector.