; and (E) any other stakeholders the Administrator determines appropriate. (b) Report Not later than 2 years after the date of enactment of this Act, the Administrator shall submit to the appropriate committees of Congress a report on the results of the study conducted under subsection (a), together with recommendations to facilitate the safe operation and integration of hypersonic aircraft into the national airspace system. (c) Definition of hypersonic In this section, the term hypersonic means an aircraft or flight operating at speeds in excess of Mach 5 and above. 909. Operating high-speed flights in high altitude Class E airspace (a) Consultation Not later than 1 year after the date of enactment of this section, the Administrator, in consultation with the Administrator of the National Aeronautics and Space Administration and relevant stakeholders, including industry and academia, shall identify the minimum altitude above the upper boundary of Class A airspace at or above which flights operating with speeds above Mach 1 generate sonic booms that do not produce appreciable sonic boom overpressures at the surface under prevailing atmospheric conditions. (b) Consultation Not later than 1 year after the date of enactment of this section, the Administrator, in consultation with the Environmental Protection Agency and other stakeholders, shall assess and report on a means for supporting continued compliance with the National Environmental Protection Act (NEPA). The Administrator shall enter into an agreement with an appropriate Federally-funded research and development center, or other independent nonprofit organization that recommends long term solutions for maintaining NEPA compliance for 1 or more over-land or near-land hypersonic and supersonic test areas that will be established. (c) Rulemaking Not later than 2 years after the date on which the Administrator identifies the minimum altitude described in subsection (a), the Administrator shall publish in the Federal Register a notice of proposed rulemaking to