What is the purpose of the T5 system?

What is the purpose of the T5 system?

• A. Opens nozzle to keep EGT at 630-650 in AB
• B. Closes nozzle to reduce EGT
• C. Adjusts flaps to maintain lift
• D. Controls fuel flow to maintain RPM

Answer: (A)

The T5 system is about regulating exhaust nozzle area to control engine temperature under afterburner operation. When afterburner is engaged, fuel flow and flame temperature rise, which pushes exhaust gas temperature (EGT) higher. By opening the variable exhaust nozzle, the hot gases expand more freely, which lowers back pressure and helps keep the turbine inlet temperature—and thus EGT—within a safe range, typically around 630–650 °C. This maintains engine health while still delivering afterburner thrust. Opening the nozzle is the key mechanism for managing EGT during afterburner; closing the nozzle would raise back pressure and tend to increase EGT rather than reduce it, and adjusting flaps or simply altering fuel flow for RPM are not the purposes of the T5 system.

The T5 system is about regulating exhaust nozzle area to control engine temperature under afterburner operation. When afterburner is engaged, fuel flow and flame temperature rise, which pushes exhaust gas temperature (EGT) higher. By opening the variable exhaust nozzle, the hot gases expand more freely, which lowers back pressure and helps keep the turbine inlet temperature—and thus EGT—within a safe range, typically around 630–650 °C. This maintains engine health while still delivering afterburner thrust.

Opening the nozzle is the key mechanism for managing EGT during afterburner; closing the nozzle would raise back pressure and tend to increase EGT rather than reduce it, and adjusting flaps or simply altering fuel flow for RPM are not the purposes of the T5 system.