Recent short-term commodity shortages and the potential for interruption of our supplies have caused concern that future U.S. defense systems may become increasingly dependent on materials that are potentially in short supply. This study inquires specifically into the prospects for material to be applied in the first stage turbine of man-rated military aircraft in 1990. The set of candidate material technologies that are in prospect is defined, and the component materials of these technologies that are potentially future supply problems are determined. A methodology was developed to combine the range of technology risks with the range of materials availability risks and overall comparisons were made. Due to the significant availability risks of chromium (as a necessary constituent of superalloys), ceramic materials appear to have the lowest long-term risks for high temperature engines. 93 pp. Ref.