; (2) ambient Pb concentrations at and around airports where piston-powered general aviation aircraft are used; and (3) mitigation measures to reduce ambient Pb concentrations, including increasing the size of run-up areas, relocating run-up areas, imposing restrictions on aircraft using aviation gasoline, and increasing the use of motor gasoline in piston-powered general aviation aircraft. (c) Report to Congress Not later than 1 year after the date of enactment of this Act, the Secretary shall submit to Congress the report developed by the National Research Council pursuant to this section. 164. Aircraft noise, emission, and fuel burn reduction program (a) In general The Secretary of Transportation may carry out an aircraft noise, emission, and fuel burn reduction research and development program. (b) Elements In carrying out the program under subsection (a), the Secretary may— (1) support efforts to accelerate the development of new aircraft, engine technologies, and jet fuels; (2) pursue lighter and more efficient turbine engine components, advanced aircraft wing designs, fuselage structures for innovative aircraft architectures, and smart aircraft and engine control systems; and (3) partner with private industry to accomplish the goals of the program. 165. Terminal sequencing and spacing Not later than 60 days after the date of enactment of this Act, the Administrator of the Federal Aviation Administration shall report to the appropriate committees of Congress on the status of Terminal Sequencing and Spacing (TSAS) implementation across all completed NextGen Metroplexes with specific information provided by airline regarding the adoption and equipping of aircraft and the training of pilots in its use. 166. Noise and health impact training (a) Study The Comptroller General of the United States shall conduct a study on— (1) while maintaining safety as the top priority, whether air traffic controllers and airspace designers are trained on noise and health impact mitigation in addition to efficiency