Unleaded Fuel for General Aviation

The Clean Air Act, passed in the late 1970s, mandating the removal of lead from most fuels due its detrimental effects on public health, yet piston-driven aircraft continue to rely on leaded aviation gas (AvGas 100LL). This fuel remains the last lead-containing fuel regulated by the Department of Transportation (DOT). Lead, added as tetraethyl lead (TEL), enhances octane levels and prevents engine detonation, vital for high-compression aircraft engines. In response to the health effects, regulating bodies like the Environmental Protection Agency (EPA) have tightened lead standards and are assessing the risk posed by AvGas. Research links even low-level lead exposure to cognitive impairments, prompting environmental groups to pressure the EPA for action. Alternatives to 100LL, such as 94UL, automotive gas, Swift Fuel (100R) and GAMI (G100UL), are under development, though technical and safety barriers remain. This research aims to analyze the status of leaded aviation fuel, its impact on emissions, and potential alternatives that could offer viable, sustainable replacements to meet aviation performance standards.