Method for detecting a failure of at least one sensor onboard an aircraft implementing wind detection, and associated system

1. A method for detecting a failure of at least one sensor onboard an aircraft, including:

measuring an airspeed of the aircraft;

measuring a geographical speed of the aircraft;

determining an instantaneous wind vector based on the measured airspeed and geographical speed;

establishing an instantaneous wind variation vector based on the determined instantaneous wind vector;

projecting the instantaneous wind variation vector on a direction of a vector of an air or geographical speed of the aircraft to obtain an instantaneous wind variation vector projection; and

determining a presence of a failure based on the instantaneous wind variation vector projection.

2. The method as recited in claim 1 wherein the determining the presence of a failure includes comparing the instantaneous wind variation vector projection with a given threshold.

3. The method as recited in claim 2 wherein a value of the given threshold varies as a function of a flight phase.

4. The method as recited in claim 1 further comprising filtering the instantaneous wind variation vector projection, before the determining the presence of a failure, using an angular band pass filter centered on the direction of the air or geographical speed.

5. The method as recited in claim 4 wherein the filtering the instantaneous wind variation vector projection includes normalizing the instantaneous wind variation vector projection in order to obtain a normalized projection, then setting the normalized projection to a power N.

6. The method as recited in claim 1 wherein the filtering the instantaneous wind variation vector projection includes calculating a scalar product between the instantaneous wind variation vector and a unitary vector coaxial to the direction of the vector of an air or geographical speed of the aircraft.

7. The method as recited in claim 1 wherein the establishing the instantaneous wind variation vector includes establishing a difference between the instantaneous wind vector and an average instantaneous wind.

8. The method as recited in claim 7 wherein the average instantaneous wind is determined from a sliding average of the instantaneous wind vector.

9. The method as recited in claim 7 wherein the establishing the instantaneous wind variation vector includes establishing a sum of differences between the instantaneous wind vector and the average instantaneous wind over a given period of time.

10. The method as recited in claim 1 further comprising measuring the airspeed in an airplane frame, the measuring the geographical speed being done in a platform frame, the determining the instantaneous wind vector including changing frames from the airspeed and/or the geographical speed.

11. The method as recited in claim 1 further comprising activating an alarm when the presence of a failure is detected in the step for determining the presence of a failure.

12. A system for detecting a failure of at least one sensor onboard an aircraft comprising:

an aircraft airspeed measurer configured to measure an airspeed of the aircraft;

an aircraft geographical speed measurer configured to measure a geographical speed of the aircraft;

an instantaneous wind vector determiner configured to determine an instantaneous wind vector based on the measured airspeed and geographical speed;

an instantaneous wind variation vector establisher configured to establish an instantaneous wind variation vector based on the determined instantaneous wind vector;

an instantaneous wind variation vector projector configured to project the instantaneous wind variation vector on a direction of a vector of an air or geographical speed of the aircraft to obtain an instantaneous wind variation vector projection; and

a failure presence determiner configured to determine a presence of a failure based on the instantaneous wind variation vector projection.