FAA Powerplant Written Practice Test

What does the exhaust gas temperature (EGT) indicator on a gas turbine engine primarily provide?

1. Information on fuel flow

2. Relative indication of turbine inlet temperature

3. Indication of engine pressure ratio

4. Measurement of exhaust pressure

The correct answer is: Relative indication of turbine inlet temperature

The exhaust gas temperature (EGT) indicator serves a crucial role in monitoring the performance and efficiency of a gas turbine engine. It primarily provides a relative indication of turbine inlet temperature (TIT). By measuring the temperature of the gases as they exit the turbine, the EGT indicator helps in assessing how well the engine is operating under various conditions. Monitoring EGT is essential because excessively high temperatures can indicate problems like overfueling or component malfunctions, which could lead to engine damage. The relationship between EGT and TIT allows engineers to deduce the thermal efficiency of the engine and make adjustments as necessary to optimize performance and ensure safe operation. While EGT may have indirect implications for fuel flow, engine pressure ratios, or exhaust pressure, it does not directly measure these factors. Therefore, the primary purpose of the EGT indicator is its direct correlation to the temperature at the turbine’s inlet, making it a vital tool in managing and understanding engine performance.