Probe heater remaining useful life determination

1. A system for an aircraft, the system comprising:

a probe positioned on the aircraft to determine environmental characteristics, wherein the probe includes a heater comprising a resistive heating element routed through the probe, and wherein an operational current is provided to the resistive heating element to provide heating for the probe;

a control circuit; and

a current sensor connected to provide a sensed current to the control circuit indicative of the operational current;

wherein the control circuit is configured to monitor the sensed current at a plurality of common points of operation of the probe over time and determine, using a predetermined function, a remaining useful life of the probe based on the operational current at each of the plurality of common points of operation.

2. The system of claim 1 , wherein the control circuit is further configured to normalize the sensed current based upon a probe temperature and store a normalized sensed current.

3. The system of claim 2 , further comprising a temperature sensor configured to sense a temperature of the probe and provide the sensed temperature to the control circuit as the probe temperature.

4. The system of claim 2 , wherein the probe temperature is a received estimated temperature from an avionics system of the aircraft.

5. The system of claim 2 , wherein the control circuit is configured to monitor the operational current over time by storing the normalized sensed current over a plurality of flights of the aircraft.

6. The system of claim 5 , wherein the control circuit is configured to calculate a half-life estimate of the resistive heating element based upon the normalized sensed current over the plurality of flights.

7. The system of claim 6 , wherein the control circuit determines and outputs the remaining useful life of the probe based upon the half-life estimate.

8. A method for determining a remaining useful life of an aircraft probe configured to determine environmental characteristics, the method comprising:

providing an operational current to a resistive heating element of the aircraft probe;

sensing, by a current sensor, the operational current to the resistive heating element as a sensed operation current;

providing the sensed operational current to the control circuit;

monitoring, by a control circuit, the sensed operational current at a plurality of common points of operation of the probe over time; and

determining, using a predetermined function, the remaining useful life of the aircraft probe based on the sensed operational current over time.

9. The method of claim 8 , wherein monitoring, by the control circuit, the operational current over time comprises normalizing the sensed operational current to the resistive heating element based upon a temperature of the aircraft probe.

10. The method of claim 9 , wherein normalizing the sensed operational current to the resistive heating element based upon the temperature of the aircraft probe comprises:

sensing, by a temperature sensor, a sensed temperature of the aircraft probe; and

normalizing the sensed operational current based upon the sensed temperature of the aircraft probe.

11. The method of claim 9 , wherein normalizing the sensed operational current to the resistive heating element based upon the temperature of the aircraft probe comprises:

determining an estimated temperature of the aircraft probe; and

normalizing the sensed operational current based upon the estimated temperature of the aircraft probe.

12. The method of claim 9 , wherein monitoring, by the control circuit, the operational current over time further comprises:

storing, by the control circuit, the normalized sensed operational current over a plurality of flights of the aircraft.

13. A probe system for an aircraft probe configured to determine environmental characteristics, the probe system comprising:

a heater comprising a resistive heating element routed through the aircraft probe, wherein an operational current is provided to the resistive heating element to provide heating for the aircraft probe;

a control circuit; and

a current sensor configured to provide a sensed current to the control circuit indicative of the operating current;

wherein the control circuit is configured to monitor the sensed current at a plurality of common points of operation of the aircraft probe over time and determine, using a predetermined function, a remaining useful life of the probe system based on the operational current at each of the plurality of common points of operation.

14. The probe system of claim 13 , further comprising a temperature sensor configured to sense a temperature of the probe system and provide the sensed temperature to the control circuit.

15. The probe system of claim 14 , wherein the control circuit is further configured to normalize the sensed current based upon the sensed temperature and store a normalized sensed current.

16. The probe system of claim 15 , wherein the control circuit is configured to monitor the operational current over time by storing the normalized sensed current over a plurality of flights of an aircraft, wherein the probe system is implemented on the aircraft.

17. The probe system of claim 16 , wherein the control circuit is configured to calculate a half-life estimate based upon the normalized sensed current over the plurality of flights.