A T5 fail is indicated by which diagnostic sign?

A T5 fail is indicated by which diagnostic sign?

• A. EGT rises out of limits, nozzle close to 0 at AB
• B. EGT drops rapidly, nozzle wide open
• C. Engine vibration with normal EGT
• D. No change in engine parameters

Answer: (A)

A T5 fail shows up when the turbine inlet temperature (EGT) goes outside its normal range, signaling an abnormal turbine-side condition or a sensor fault. In this scenario, the combination of EGT rising out of limits and the afterburner nozzle held near closed (close to 0) points to a fault pattern where temperature control is compromised and the exhaust flow is restricted, which tends to push EGT higher than safe limits. The other signs don’t align with a T5 fault: EGT dropping rapidly with the nozzle wide open would imply unusual cooling or over-expansion not typically associated with a T5 fault; engine vibration with normal EGT suggests a mechanical issue elsewhere; and no change in engine parameters means no fault indication.

A T5 fail shows up when the turbine inlet temperature (EGT) goes outside its normal range, signaling an abnormal turbine-side condition or a sensor fault. In this scenario, the combination of EGT rising out of limits and the afterburner nozzle held near closed (close to 0) points to a fault pattern where temperature control is compromised and the exhaust flow is restricted, which tends to push EGT higher than safe limits. The other signs don’t align with a T5 fault: EGT dropping rapidly with the nozzle wide open would imply unusual cooling or over-expansion not typically associated with a T5 fault; engine vibration with normal EGT suggests a mechanical issue elsewhere; and no change in engine parameters means no fault indication.