FAA Powerplant Written Practice Test

Why are turbine blades generally more susceptible to operating damage than compressor blades?

1. Exposure to high operating temperatures

2. Higher rotational speeds

3. Thinner blade construction

4. Increased vibration

The correct answer is: Exposure to high operating temperatures

Turbine blades are generally more susceptible to operating damage primarily due to their exposure to high operating temperatures. In turbine engines, these blades are subjected to extreme thermal environments as they must effectively handle the high-temperature gases produced during combustion. This exposure leads to significant thermal stresses, which can cause phenomena such as oxidation, creep, and thermal fatigue. Because turbine blades operate in a hotter environment than compressor blades, they require advanced materials and coatings to withstand these conditions and maintain their structural integrity. The operating temperatures in a turbine can exceed the critical limits for many materials, making them more vulnerable to damage compared to compressor blades, which typically operate under lower thermal stress conditions. This focus on high operating temperatures and their effects helps to clarify why turbine blades face a greater risk of damage. The other factors, such as rotational speeds or vibrations, while important, do not solely account for the heightened susceptibility to damage as effectively as thermal exposure does.