FAA Powerplant Written Practice Test

What makes turbine blades more susceptible to damage compared to compressor blades?

1. Higher speed operations

2. Exposure to high temperatures

3. Stronger material composition

4. Longer lifespan

The correct answer is: Exposure to high temperatures

Turbine blades are indeed more susceptible to damage primarily due to exposure to high temperatures. In a gas turbine engine, after the combustion process, the hot gases that flow through the turbine section can reach extremely high temperatures, often exceeding the material limits for many substances. This high-temperature environment can lead to a range of issues such as thermal fatigue, creep, and oxidation, all of which can contribute to blade deterioration over time. While compressor blades do also operate at high speeds and experience significant stress, they do not face the same extreme thermal conditions as turbine blades. The materials used for turbine blades are specifically engineered to withstand high temperatures, but they still degrade faster when compared to the conditions faced by compressor blades, which are typically at lower temperatures. Thus, exposure to high temperatures is a critical factor that explains the heightened vulnerability of turbine blades to damage compared to their compressor counterparts.