; and (E) consider differences between subsonic and supersonic aircraft including differences in thrust requirements at equivalent gross weight, engine requirements, aerodynamic characteristics, operational characteristics, and other physical properties. (3) Noise and performance data The requirement of the Administrator to issue a notice of proposed rulemaking under paragraph (1) shall apply only if an application contains sufficient aircraft noise and performance data as the Administrator finds necessary to determine appropriate noise standards and operating limitations for the aircraft type consistent with section 44715 of title 49, United States Code. (4) Final rule Not later than 18 months after the end of the public comment period provided in the notice of proposed rulemaking required under paragraph (1), the Administrator shall publish in the Federal Register a final rule applying solely to the aircraft model submitted for type certification. (5) Review of rules of civil supersonic flights Beginning December 31, 2020, and every 2 years thereafter, the Administrator shall review available aircraft noise and performance data, and consult with heads of appropriate Federal agencies, to determine whether section 91.817 of title 14, Code of Federal Regulations, and Appendix B of part 91 of title 14, Code of Federal Regulations, may be amended, consistent with section 44715 of title 49, United States Code, to permit supersonic flight of civil aircraft over land in the United States. (6) Implementation of noise standards The portion of the regulation issued by the Administrator of the Federal Aviation Administration titled Revision of General Operating and Flight Rules and published in the Federal Register on August 18, 1989 (54 Fed. Reg. 34284) that restricts operation of civil aircraft at a true flight Mach number greater than 1 shall have no force or effect beginning on the date on which the Administrator publishes in the Federal Register a final rule specifying sonic boom noise standards for civil supersonic