The present invention provides a system and method for generation of nitrogen enriched air for inerting aircraft fuels tanks. One embodiment of the present invention includes a duct assembly; a primary heat exchanger; a gas generating system heat exchanger; a first temperature sensor; a second temperature sensor; a controller monitor; a valve; an air separation module assembly having a primary module and a secondary module; at least one flow control orifice; and a pressure sensor. The present invention utilizes a minimal complement of components and streamlined processes, thus minimizing structural and operational costs while optimizing performance and safety features.