Aircraft brake health monitoring system and method

1. A method of estimating health of aircraft brake system friction material, comprising the steps of:

sensing a temperature of the friction material;

supplying the sensed temperature to a processor-implemented thermal model, the processor-implemented thermal model configured to estimate friction material temperatures at one or more locations on the friction material;

supplying the estimates of friction material temperatures to a processor-implemented thermal oxidation model, the processor-implemented thermal oxidation model configured, based on the estimates of friction material temperatures, to estimate friction material loss due to thermal oxidation;

supplying data representative of runway fluid exposure to a processor-implemented catalytic oxidation model, the processor-implemented catalytic oxidation model configured, based on the runway fluid exposure, to estimate friction material loss due to catalytic oxidation; and

estimating the health of the friction material based on the estimates of friction material loss from the processor-implemented thermal oxidation model and the processor-implemented catalytic oxidation model.

2. The method of claim 1 , wherein the data representative of runway fluid exposure comprise:

data representative of chemical composition of the runway fluid; and

data representative of exposure time to the runway fluid.

3. The method of claim 1 , further comprising:

supplying data representative of aircraft landing conditions to a processor-implemented wear model, the processor-implemented wear model configured, based on the aircraft landing conditions, to estimate friction material loss due to wear.

4. The method of claim 3 , wherein the step of estimating the remaining useful life is additionally based on friction material loss from the processor-implemented wear model.

5. The method of claim 3 , wherein the data representative of aircraft landing conditions comprise:

aircraft landing energy;

number of taxi stops; and

ambient temperature while landing.

6. The method of claim 3 , further comprising:

supplying the data representative of aircraft landing conditions from an aircraft condition monitoring system (ACMS).

7. The method of claim 1 , further comprising:

generating a condition indicator representative of friction material loss.

8. The method of claim 7 , wherein the condition indicator is a multi-dimensional state variable comprising at least a condition indicator representative of friction material loss due to thermal oxidation and a condition indicator representative of catalytic oxidation.

9. The method of claim 8 , further comprising:

comparing trends of each condition indicator to a predetermined threshold value; and

generating a health indicator for each condition indicator based on the trend comparisons.

10. A system for estimating remaining useful life of brake system friction material, comprising:

a temperature sensor configured to sense a temperature that is at least representative of the friction material and supply a friction material temperature signal;

a runway fluid data source configured to at least selectively supply data representative of runway fluid exposure; and

a processor coupled to receive the friction material temperature signal and the data representative of runway fluid exposure and configured, upon receipt thereof, to:

estimate friction material temperatures at one or more locations on the friction material,

estimate friction material loss due to thermal oxidation based on the estimates of friction material temperatures,

estimate friction material loss due to catalytic oxidation based on the runway fluid exposure, and

estimate the remaining useful life of the friction material based on the estimates of friction material loss.

11. The system of claim 10 , wherein the processor is further configured to implement a thermal model to estimate the friction material temperatures at one or more locations on the friction material brake.

12. The system of claim 10 , wherein the processor is further configured to implement a thermal oxidation model to estimate the friction material loss due to thermal oxidation.

13. The system of claim 10 , wherein the processor is further configured to implement a catalytic oxidation model to estimate friction material loss due to catalytic oxidation.

14. The system of claim 10 , wherein the data representative of runway fluid comprises:

data representative of chemical composition of the runway fluid; and

data representative of exposure time to the runway fluid.

15. The system of claim 10 , further comprising:

a landing conditions data source configured to supply data representative of aircraft landing conditions,

wherein the processor is further configured to (i) implement a wear model and (ii) estimate friction material loss due to wear based on the aircraft landing conditions.

16. The system of claim 15 , wherein the data representative of aircraft landing conditions comprise:

aircraft landing energy;

number of taxi stops; and

ambient temperature while landing.

17. The system of claim 15 , wherein the landing conditions data source comprises an aircraft condition monitoring system (ACMS).

18. The system of claim 10 , further comprising:

a display device in communication with the processor and configured to render images,

wherein the processor is further configured to:

generating condition indicators representative of friction material loss, and

supply image rendering display commands to the display device that cause the display device to render images representative of the condition indicators.

19. The system of claim 18 , wherein the processor is further configured to:

compare trends of each condition indicator to a predetermined threshold value;

generate a health indicator for each condition indicator based on the trend comparisons; and

supply image rendering display commands to the display device that cause the display device to render images representative of the health indicators.

20. The system of claim 19 , wherein the processor is further configured to selectively download the condition and health indicators to a remote server.