The overall objective of the Advanced Turbine System (ATS) Phase 3 Cooperative Agreement between GE and the US Department of Energy (DOE) is the development of the GE 7H and 9H combined cycle power systems. The major effort will be expended on detailed design. Validation of critical components and technologies will be performed including: hot gas path component testing, sub-scale compressor testing, steam purity test trials, and rotational heat transfer confirmation testing. Processes will be developed to support the manufacture of the first system, which will be sited and operated in Phase 4. Technology enhancements that are not required for the first machine design but will be critical for future ATS advances in performance, reliability, and costs will be initiated. Long-term tests of materials to confirm design life predictions will continue. This initial report summarizes work accomplished during the third quarter of 1995. The most significant accomplishments reported include the following. Overall design continued, progressing from preliminary and conceptual design activities to detailed design activities. The aerodynamic design of six out of eight 9H turbine airfoils was completed. The 9H compressor design concept was finalized including rotor configuration, aerodynamic design of compressor, and compressor structure. Conceptual on-base and external piping layout was begun. The ATS Phase 3 Cooperative Agreement was negotiated and signed.