The Brittle Materials Design, High Temperature Gas Turbine program is to demonstrate successful use of brittle materials in demanding high temperature structural applications. A small vehicular gas turbine and a large stationary gas turbine, each utilizing uncooled ceramic components, will be used in this iterative design and materials development program. In the vehicular turbine project, steady state and transient stresses were determined for a monolithic turbine rotor of hot-pressed silicon nitride. A new rotor concept, using both hot-pressed and reaction-sintered silicon nitride, has been analyzed for steady- state stresses; work on bonding the two materials appears promising. Improvements in chemically vapor deposited silicon carbide rotors include the forming of hoops of sufficient thickness and the production of material of considerably improved purity. Blade cracking of the first stage ceramic stator was duplicated on a thermal shock test rig, leading to improved durability through a change in the blade design. Some fabrication variables of reaction- sintered silicon nitride were studied, which indicate methods for material improvements. In the stationary turbine project, a model of the 3-piece stator vane assembly demonstrated that design integrity was maintained when differential motion exceeded design limits fivefold. The 3-dimensional finite element stress and heat transfer analytical program has been applied to rotor blades, and preliminary results are presented. Statistical data treatment has been applied to hot-pressed silicon nitride, and additional property data plus corrosion testing results are presented for hot-pressed silicon carbide.