FAA Powerplant Written Practice Test

What is the result of operating a turbine engine with excessively high EGT?

1. Increased fuel efficiency

2. Damage to turbine section and reduced turbine component life

3. Improved engine performance

4. Extended maintenance intervals

The correct answer is: Damage to turbine section and reduced turbine component life

Operating a turbine engine with excessively high exhaust gas temperature (EGT) can lead to significant damage to the turbine section and reduces the lifespan of the turbine components. High EGT indicates that the engine is running hotter than its design parameters, which can result in several adverse effects. When the EGT exceeds recommended limits, it can cause thermal stresses that exceed the material properties of turbine blades and other critical components. This can lead to physical changes in the materials, such as creep, melting, or other forms of degradation, all of which severely compromise the structural integrity and performance of the engine. These effects can result in costly repairs and replacements, significantly increasing operational expenses and decreasing safety. In contrast, excessively high EGT does not lead to increased fuel efficiency, improved engine performance, or extended maintenance intervals. Instead, it tends to increase fuel consumption due to the engine operating in a non-optimal manner and results in more frequent maintenance needs due to the damage sustained during high-temperature operation. Thus, the correct choice emphasizes the detrimental effects on engine health and longevity.