The National Academy of Sciences recently released the report “Options for Reducing Lead Emissions from Piston-Engine Aircraft.” The report encourages multiple strategies to reduce lead emissions from small aircraft. While acknowledging the difficulties with finding a suitable fuel alternative, the report finds that a non-leaded aviation fuel is still the ideal solution. In the meantime, the report recommends mitigating strategies: 1) The highest lead contamination occurs at the airport, with people working at the airport at the greatest risk. Locate runup areas and test areas away from workers as much as possible. Educate airport workers on the danger of lead emissions. 2) The industry should switch the standard fuel to 100 VLL (very low lead), which has 20% less lead. According to the National Academy of Sciences, 100 VLL would satisfy every aircraft currently operating on 100LL—the minimum lead content is the same, the maximum lead content is lowered, and it would require tighter blending tolerances.

Still active is the Piston Aviation Fuels Initiative (PAFI), a joint government and industry initiative created to develop a path forward for identifying, evaluating and deploying the most promising unleaded replacements for 100 low lead aviation gasoline. Development and prescreening testing are taking place at both private and public testing facilities across the country. The FAA’s William J. Hughes Technical Center is providing engine-testing services through cooperative research and development agreements (CRADA) with the individual fuel companies. While COVID-19 has delayed the completion of the prescreening tests, the tentative schedule is to restart formal PAFI testing in 2021.