Which marking materials are generally permitted during inspection of turbine engine components exposed to high temperatures?

During the inspection of turbine engine components, particularly those exposed to high temperatures, it is essential to use marking materials that can withstand these conditions without compromising the integrity of the components.

The correct answer includes layout dye, wax or grease pencil, and chalk. Layout dye is specifically formulated to remain visible on metallic surfaces even under varying temperatures and can easily be removed without leaving residues that could interfere with engine function. Wax or grease pencils are also suitable because they do not chip or flake, can withstand higher temperatures, and are easily wiped off when necessary. Chalk is lightweight and non-permanent, making it useful for temporary markings that will not damage the surfaces of components.

In contrast, the other options present marking materials that could lead to issues in high-temperature environments. For example, permanent markers and oil-based inks can degrade or emit harmful vapors when subjected to the heat inherent in turbine engines, potentially leading to contamination. Similarly, paints and Whiteout can create residues that might affect the performance and balance of engine components. Thus, the selected marking materials in the correct answer ensure both effective marking for inspection purposes and maintain the necessary standards for engine operation.