; and (ii) assist the Administrator of the Federal Aviation Administration in enabling— (I) the safe commercial deployment of civil supersonic aircraft technology; and (II) the safe and efficient operation of civil supersonic aircraft. (B) A subsonic flight demonstrator aircraft project to advance aircraft designs and technologies that enable significant increases in energy efficiency and reduced life-cycle emissions in the aviation system while reducing noise and emissions. (C) A series of large-scale X-plane demonstrators that are— (i) developed sequentially or in parallel; and (ii) each based on a set of new configuration concepts or technologies determined by the Administrator to demonstrate— (I) aircraft and propulsion concepts and technologies and related advances in alternative propulsion and energy; and (II) flight propulsion concepts and technologies. (2) Elements For each project under paragraph (1), the Administrator shall— (A) include the development of X-planes and all necessary supporting flight test assets; (B) pursue a robust technology maturation and flight test validation effort; (C) improve necessary facilities, flight testing capabilities, and computational tools to support the project; (D) award any primary contracts for design, procurement, and manufacturing to United States persons, consistent with international obligations and commitments; (E) coordinate research and flight test demonstration activities with other Federal agencies and the United States aviation community, as the Administrator considers appropriate; and (F) ensure that the project is aligned with the Aeronautics Strategic Implementation Plan and any updates to the Aeronautics Strategic Implementation Plan. (3) United States person defined In this subsection, the term United States person means— (A) a United States citizen or an alien lawfully admitted for permanent residence to the United States