What is a typical action if a blade is found to have coating delamination during inspection?

• A. Continue operation without remediation.
• B. Detach the blade and discard the entire wheel.
• C. Coat the blade with a temporary sealant and continue.
• D. Replace the blade or perform coating repair per OEM.

Answer: (D)

Coating integrity on turbine blades is critical because delamination can allow hot gases to penetrate behind the coating, leading to accelerated wear, spall, overheating, and potential blade failure. When coating delamination is found, the safe and proper action is to follow the OEM specifications: replace the blade or perform the coating repair per the OEM. This ensures the repair or replacement uses approved materials, procedures, and quality checks, preserving structural integrity, compatibility with the engine, and traceability.

Others options aren’t appropriate for safety and reliability reasons. Continuing operation without remediation risks coating failure and debris entering the engine. Dismissing only part of the issue or applying a temporary sealant doesn’t address the underlying adhesion problem and won’t withstand service conditions. Replacing just the blade or performing an OEM-approved coating repair is the correct, certified approach.