How would you differentiate a faulty sensor from a faulty display in an avionics fault?

How would you differentiate a faulty sensor from a faulty display in an avionics fault?

• A. Cross-check with other sensors and channels
• B. Replace the display first
• C. Restart the system and wait
• D. Ignore one reading

Answer: (A)

When diagnosing an avionics fault, use redundancy and cross-checking to separate sensor faults from display faults. The same parameter is usually provided by multiple sensors or channels that feed the data bus and the cockpit displays. If the suspect reading disagrees with other independent sources that are consistent with each other, the issue is most likely in that sensor. If the other sensors and channels all agree and the display still shows the same value (or form of data) across multiple indicators, the problem is more likely in the display or its data path rather than in the sensor itself. Diagnostic logic often also compares related parameters to spot implausible values, helping confirm whether the sensor data are internally inconsistent or if the display is simply misreading or misrepresenting valid data.

When diagnosing an avionics fault, use redundancy and cross-checking to separate sensor faults from display faults. The same parameter is usually provided by multiple sensors or channels that feed the data bus and the cockpit displays. If the suspect reading disagrees with other independent sources that are consistent with each other, the issue is most likely in that sensor. If the other sensors and channels all agree and the display still shows the same value (or form of data) across multiple indicators, the problem is more likely in the display or its data path rather than in the sensor itself. Diagnostic logic often also compares related parameters to spot implausible values, helping confirm whether the sensor data are internally inconsistent or if the display is simply misreading or misrepresenting valid data.