What is the most common cause of gas path erosion?

• A. Ingestion of sand, dirt, dust, and other fine airborne contaminants
• B. Excessive engine RPM
• C. Fuel impurities in the fuel system
• D. Corrosion from humidity in the inlet

Answer: (A)

Gas path erosion happens when abrasive particles in the incoming air strike and wear away material on compressor and turbine surfaces. The most common cause is ingestion of sand, dirt, dust, and other fine airborne contaminants carried with the air entering the engine. These hard particles cause micro-cutting and pitting on blade and vane surfaces, especially in dusty or sandy environments and when filtration isn’t able to remove them effectively.

Higher engine speeds can increase the energy of the air and particles that do make it through, but erosion is driven by the presence of abrasive ingested matter, not just RPM itself. Fuel impurities tend to cause deposits or fuel system issues rather than direct mechanical erosion of gas path components. Humidity can lead to corrosion, which is a different degradation mechanism from erosion caused by particle impingement.