Exposure of gas turbine materials to a PFBC effluent under the Long-Term Materials Test Program has reached 1507 hours. Unprotected nickel and cobalt base blade and vane alloys show susceptibility to hot corrosion at 1500/sup 0/F (gas temperature), 1300/sup 0/F, and 1100/sup 0/F (air-cooled pins). Precious metal aluminide and M (Co,Fe) CrAIY overlay coatings continue to show good resistance to corrosion above 1450/sup 0/F, but are susceptible to varying degrees of pitting attack between 1050 and 1300/sup 0/F. Significant erosion/corrosion degradation of both base alloys and protective coatings/claddings has been observed on airfoil specimens exposed at 1350/sup 0/F, 800 to 900 fps and dust loadings less than 100 ppM for 1085 hours. Corrosion predominately occurred in areas of direct particle impaction; i.e., leading edge and pressure surface, indicating an erosion/corrosion synergism. At gas velocities of 1200 to 1400 fps, a platinum-aluminide coated IN-738 pin experienced a metal recession rate of 8 mils/1000-hours. The PFBC facility continues to show excellent operational reliability, accumulating over 1100 test hours this quarter. The only concern from an operations standpoint is the gradual thinning of the in-bed heat exchanger tubing at a rate of about 5 mils/100 hours off the diameter.