System and method for converting an aircraft from a flight condition lying outside a permissible flight condition range to a flight condition lying within the permissible flight condition range

1. A system configured to convert an aircraft from a flight condition lying outside a permissible flight condition range to a flight condition lying within the permissible flight condition range, that is assigned to a sensor system and a control device of the aircraft, comprising:

a control override module configured to take over or returning the control authority over the aircraft based on a control take-over signal and for feeding control set points if the control takeover signal is set;

a maneuver selection module configured to provide and storing at least one conversion strategy with associated maneuver information and for selecting a conversion strategy depending on measured variables of the sensor system;

a threshold value generator configured to calculate the flight range limit on the basis of measured variables of the sensor system;

a decision module functionally connected to the threshold value generator and the sensor system and to receive from the value generator the calculated flight range limit and from the sensor system the measured variables, and to generate a control takeover signal based on a comparison of the flight range limit with the measured variables and to transmit it to the control override module, the command generator and the maneuver selection module;

a command generator functionally connected, on the one hand, to the decision module and the maneuver selection module and, on the other hand, to the control override module and, when the control takeover signal is set, calculates the control set points based on the maneuver information and transmits them to the control override module.

2. A flight guidance system according to claim 1 , wherein:

the command generator is additionally functionally connected to the sensor system;

the command generator comprises a position control unit that calculates the control set points with the aid of measured variables of the sensor system such that the aircraft maintains a flight attitude preset through the maneuver information.

3. A flight guidance system according to claim 1 , wherein:

the threshold value generator additionally comprises functions with which a strategy change limit can be calculated and supplied to the decision module;

the decision module additionally is functionally connected to the maneuver selection module and transmits thereto a strategy change signal based on the comparison of the strategy change limit with measured variables of the sensor system, whereby the stored conversion strategy is replaced by a different one and the maneuver information is adjusted.

4. A method for converting an aircraft from a flight condition lying outside a preset flight condition range to a flight condition lying within the flight condition range, on the basis of measured variables of a sensor system, said method comprising:

selecting and storing a conversion strategy of at least one alternative based on the measured variables of the sensor system, whereby the conversion once selected and stored is replaced as a reaction to external disturbances by a then more favorable conversion strategy;

calculating a strategy change threshold value, comparing the strategy change threshold value with measured variables of the sensor system in order to generate the strategy change signal when the strategy change threshold value is exceeded, and replacing the stored conversion strategy by a different one with the simultaneous adjustment of the maneuver information;

calculating a flight condition range limit from the measured variables of the sensor system;

comparing the measurement data of the sensor system with the flight condition range limit in order to activate the control override module, take over the aircraft control and perform the maneuver established by the conversion strategy, if said limit is exceeded;

generating a control set point in the command generator and feeding said control set point into the aircraft control such that the aircraft implements the selected conversion strategy;

comparing the measurement data of the sensor system with the flight condition range limit in order to deactivate the control override module and to hand over the aircraft control if it falls below said limit.

5. A method according to claim 4 , wherein:

the flight condition range limit is represented by a limiting speed that is calculated as a function of the measured variables delay, pitch position angle, roll position angle, angle of attack, angle of yaw, height above mean sea level and aircraft mass.

6. A method according to claim 4 , wherein:

the control set point of the command generator comprises an angle of attack set point, an angle of yaw set point and/or a roll position regulation.

7. A flight guidance system according to claim 1 , wherein:

said control override module for taking over or returning the control authority over the aircraft based on a control take-over signal and for feeding control set points if the control takeover signal is set comprises:

a control override module for taking over control authority over the aircraft based on a control take-over signal indicative of unstable aircraft dynamics.

8. A method according to claim 4 , wherein:

said calculating a flight condition range limit comprises calculating a flight condition range limit as indicative of a limit of stable aircraft dynamics.