STORY BY LINDSEY MCFARREN he Environmental Protection Agency recently proposed a formal determination that lead emissions from aircraft operating on leaded fuel cause or contribute to air pollution, endangering public health and welfare. The action is a follow-up to the 2010 advanced notice of proposed rulemaking on the same topic. In that ANPRM, the agency anticipated this proposal to be published in 2017 or 2018. The determination is in accordance with section 231(a) of the Clean Air Act and is what the agency calls an " endangerment finding. " T While the determination is subject to public notice and comment, the EPA plans to issue any final endangerment determination in 2023. The finding would not propose aircraft engine lead emissions standards. Rather, later proposals could include regulatory standards for lead emissions and would also " trigger the FAA's statutory mandate to prescribe standards for the composition or chemical or physical properties of an aircraft fuel or fuel additive to control or eliminate aircraft lead emissions, " according to the EPA. Two FAA-industry initiatives aim to transition the piston-engine fleet to unleaded fuel in the future: the Piston Aviation Fuels Initiative and the FAAindustry partnership to Eliminate Aviation Gasoline Lead Emissions. EAGLE is a government-industry partnership to safely eliminate the use of leaded aviation fuel by the end of 2030, without compromising aviation safety and the economic and broader public benefits of general aviation. In recent public comments, David Boulter, the FAA's Continued on following page avionics news * december 2022 37