If NG signal is lost, what happens?

If NG signal is lost, what happens?

• A. No change occurs
• B. ENG OUT warning light and audio appear with 0% NG indicated
• C. ENG IN warning appears
• D. ENG OUT extinguishes and NG stays at current value

Answer: (B)

When Ng (gas generator speed) data is unavailable, the engine indication logic treats that Ng reading as invalid and switches to a fail-safe indication. In this case, the cockpit shows a 0% Ng value to clearly signal that there is no valid Ng data, and it triggers the ENG OUT warning light with an audio alert to warn the crew that a sensor fault or loss of signal may be present. This combination alerts you that you cannot rely on the Ng indication and should base engine assessments on other parameters (like torque and ITT) while troubleshooting the sensor fault.

When Ng (gas generator speed) data is unavailable, the engine indication logic treats that Ng reading as invalid and switches to a fail-safe indication. In this case, the cockpit shows a 0% Ng value to clearly signal that there is no valid Ng data, and it triggers the ENG OUT warning light with an audio alert to warn the crew that a sensor fault or loss of signal may be present. This combination alerts you that you cannot rely on the Ng indication and should base engine assessments on other parameters (like torque and ITT) while troubleshooting the sensor fault.