FAA Powerplant Written Practice Test

Why are turbine blades more susceptible to operating damage compared to compressor blades?

1. They are made of weaker material

2. Exposure to high operating temperatures

3. Higher rotational speeds

4. Increased vibration levels

The correct answer is: Exposure to high operating temperatures

Turbine blades experience greater susceptibility to operating damage primarily due to their exposure to high operating temperatures. In a turbine engine, these blades operate in a hot environment where temperatures can exceed 1,000 degrees Celsius (1,800 degrees Fahrenheit). This high temperature can lead to various forms of thermal damage, such as oxidation, creep, and thermal fatigue, which can compromise the structural integrity of the blades. The materials used for turbine blades are specially designed to withstand these intense conditions, but prolonged exposure to such high temperatures can still result in damage that impacts performance and longevity. Unlike compressor blades, which mainly operate in cooler airflow and are less thermally stressed, turbine blades have to maintain performance under extreme thermal conditions, making them more vulnerable to damage. While the other factors listed, such as rotational speeds, material strength, and vibration levels also play a role in the overall design and durability of turbine blades, the critical issue of high operating temperatures is what fundamentally increases their susceptibility to damage compared to compressor blades.