A system for monitoring a critical component on an aircraft, comprising: a differential current sensor configured for detecting an electrical differential current of the critical component, and generating an electrical differential current signal from the detected electrical differential current, the electrical differential current being a difference between a first electrical current input into the critical component and a second electrical current returned from the critical component; and a differential current processor configured for comparing the electrical differential current signal to at least one differential current threshold, wherein the at least one differential current threshold comprises a first differential current threshold and a second differential current threshold greater than the first differential current threshold, wherein the differential current processor is configured for triggering a precautionary action based on the comparison between the electrical differential current signal and the first differential current threshold, and triggering a failure indication based on the comparison between the electrical differential current signal and the second differential current threshold, wherein the differential current processor is further configured for: - upon determining that the electrical current signal exceeds the first differential current threshold, monitoring a deterioration trend of the critical component by tracking variations in the electrical differential current of the critical component over time, and - processing the electrical differential current signal by performing: (i) filtering the electrical differential current signal prior to the comparison to remove current spike bursts from the electrical differential current signal, and (ii) delaying the electrical differential current signal prior to the comparison to eliminate false triggering of the precautionary action otherwise caused by inadvertent transients in the electrical differential current signal. a differential current sensor configured for detecting an electrical differential current of the critical component, and generating an electrical differential current signal from the detected electrical differential current, the electrical differential current being a difference between a first electrical current input into the critical component and a second electrical current returned from the critical component; and a differential current processor configured for comparing the electrical differential current signal to at least one differential current threshold, wherein the at least one differential current threshold comprises a first differential current threshold and a second differential current threshold greater than the first differential current threshold, wherein the differential current processor is configured for triggering a precautionary action based on the comparison between the electrical differential current signal and the first differential current threshold, and triggering a failure indication based on the comparison between the electrical differential current signal and the second differential current threshold, wherein the differential current processor is further configured for: - upon determining that the electrical current signal exceeds the first differential current threshold, monitoring a deterioration trend of the critical component by tracking variations in the electrical differential current of the critical component over time, and - processing the electrical differential current signal by performing: (i) filtering the electrical differential current signal prior to the comparison to remove current spike bursts from the electrical differential current signal, and (ii) delaying the electrical differential current signal prior to the comparison to eliminate false triggering of the precautionary action otherwise caused by inadvertent transients in the electrical differential current signal. - upon determining that the electrical current signal exceeds the first differential current threshold, monitoring a deterioration trend of the critical component by tracking variations in the electrical differential current of the critical component over time, and - processing the electrical differential current signal by performing: (i) filtering the electrical differential current signal prior to the comparison to remove current spike bursts from the electrical differential current signal, and (ii) delaying the electrical differential current signal prior to the comparison to eliminate false triggering of the precautionary action otherwise caused by inadvertent transients in the electrical differential current signal.