Advanced technology air separation modules for use in on-board Inert gas generation systems (OBIGGS) were investigated in a recently completed Air Force development program. These modules use hollow fiber permeable membranes that are compatible with a fighter aircraft environment and have no moving parts. Extensive ground testing revealed that the advanced modules offer an order of magnitude savings of weight and volume compared to other air separation modules. Hence, the advanced modules were used in an in-dapth study of OBIGGS for fighter aircraft applications. A best choice OBIGGS for a generic ATF configuration and a comparison of the best choice OBIGGS with other aircraft fuel tank fire protection systems are discussed.