||Advanced gas turbine engines for military/commercial fixed-wing and rotary-wing aircraft use thermal/environmental barrier coatings (T/EBCs) in the high-temperature sections of the engine for improved efficiency and power. In many places throughout the world, commercial and military aircraft are operating in particulate-laden atmospheres, such as sandy deserts, volcanic zones, and polluted mega-cities. For rotorcraft gas turbine engines, the sand ingestion is particularly adverse during take-off, near-ground hovering, and landing conditions. Although most rotorcraft gas turbine engines are fitted with inlet particle separators, they are not efficient in filtering fine particles (75 micrometers or below). The presence of these fine solid particles in the working fluid medium has an adverse effect on the durability of protective coatings on turbomachinery components and the overall performance of the engine. Typical damage includes coating wear, blocked cooling channels, sand glazing, calcia-magnesia-alumino-silicate (CMAS) attack, and oxidation. Environmental particulate damage can cause rapid performance deterioration, which has lead to the loss of aircraft. This symposium will provide researchers the opportunity to discuss state-of-the-art computational and experimental research efforts aimed at understanding the physico-chemical interactions of fine environmental particulate with the advanced coating materials that protect metallic and ceramic engine components.