T5 fail indications include which symptom?

T5 fail indications include which symptom?

• A. EGT rises out of limits, nozzle close to 0 at AB
• B. EGT rises normally, nozzle full open
• C. No EGT change, nozzle mid-position
• D. No indication of T5 issue

Answer: (A)

When a sensor in the turbine section (T5) fails, the engine’s protection logic can misinterpret the turbine temperature and react as if the engine is overheating. That leads to the temperature indication (EGT) rising beyond permissible limits. In response, the control system may command the afterburner nozzle toward a closed position to reduce turbine inlet temperature and protect the engine. So the combination of an EGT spike out of limits with the nozzle near fully closed at afterburner is the telltale sign of a T5 fault. Normal transient operation would show an acceptable EGT rise with the nozzle open as fuel flow and turbine temperature respond; no EGT change with the nozzle mid-position isn’t consistent with a T5 fault; and no indication of a T5 issue would mean no fault flags at all.

When a sensor in the turbine section (T5) fails, the engine’s protection logic can misinterpret the turbine temperature and react as if the engine is overheating. That leads to the temperature indication (EGT) rising beyond permissible limits. In response, the control system may command the afterburner nozzle toward a closed position to reduce turbine inlet temperature and protect the engine. So the combination of an EGT spike out of limits with the nozzle near fully closed at afterburner is the telltale sign of a T5 fault.

Normal transient operation would show an acceptable EGT rise with the nozzle open as fuel flow and turbine temperature respond; no EGT change with the nozzle mid-position isn’t consistent with a T5 fault; and no indication of a T5 issue would mean no fault flags at all.