; and (4) any practices imposed by an airport operator that prevent an FBO from fully disclosing fees and charges. (c) Report required Not later than 18 months after the date of enactment of this section, the Comptroller shall submit a report to the appropriate committees of Congress containing the results of the review required by this section. 620B. Aviation fuel in Alaska (a) In general The Administrator and the Administrator of the Environmental Protection Agency shall not restrict the continued use and availability of 100-octane low lead aviation gas in the State of Alaska through December 31, 2034. (b) GAO report on transitioning to unleaded aviation gas in the State of Alaska (1) Evaluation The Comptroller General of the United States shall conduct an evaluation of the following: (A) The aircraft, routes, and supply chains in the State of Alaska utilizing leaded aviation gasoline, including identification of remote and rural communities that rely upon leaded aviation gasoline. (B) The estimated costs and benefits of transitioning aircraft and the supply chain in the State of Alaska to aviation fuel that meets the requirements described in clauses (i) and (ii) of section 47107(a)(22)(B) of title 49, United States Code, as added by section 620, including direct costs of new aircraft and equipment and indirect costs, including transportation from refineries to markets, foreign imports, and changes in leaded aviation gasoline prices as a result of reduced supply. (C) The programs of the Environmental Protection Agency, the FAA, and other government agencies that can be utilized to assist individuals, communities, industries, and the State of Alaska with the costs described in subparagraph (B). (D) A reasonable timeframe to permit any limitation on 100-octane low-lead aviation gasoline in the State of Alaska. (E) Other logistical considerations associated with the transition described in subparagraph (B). (2) Report Not later than 3 years after the date of enactment of this section, the Comptroller General