Recent and projected trends in the quality and proliferation of the threat-particularly in Europe-focus increased attention on the defensive facets of the counterair mission area for future tactical forces. The “overhead” character of air defense and the lopsided numerical advantage of the Warsaw Pact place emphasis on high productivity for future air defense fighters. A recent Grumman/Raytheon study sponsored by the AFFDL examined technology needs for future defensive counterair aricraft. The arena for that examination was theater air defense of NATO in the 1990's. This paper presents results of that effort with emphasis on the characteristics and technology complements of alternative concepts examined during the study. Five distinctly different weapon system designs emerged as competitive alternatives. These ranged from a small, low cost, transonic fighter armed with short range, IR guided missiles and deployed in quantity, to a large, sophisticated, and relatively expensive supersonic fighter/interceptor employing long range radar directed missiles. Study conclusions regarding desired capabilities for future air defense fighter alternatives include the identification of specific advanced technologies which have the potential to efficiently provide those capabilities.