Aviation Gasoline (2024)

Aviation gasoline (avgas) is the aviation fuel most commonly used in piston-engine aircraft within the general aviation community. Avgas remains the only transportation fuel in the United States to contain lead. More than 222,600 registered piston-engine aircraft can operate on leaded avgas. The most common and reliable type of avgas is 100 octane Low Lead, also known as 100LL. This leaded fuel contains tetra-ethyl-lead (TEL), which is an additive used to prevent engine damage at higher power settings. Although the FAA does not have direct regulatory responsibility for aviation fuels, it provides the initial certification approval of the aircraft with the fuel it operates on, and it oversees aircraft operators to ensure use of the correct fuel.

Getting the Lead Out

The FAA is working with critical government and industry partners to develop a multi-layered strategy to reduce and ultimately eliminate lead and its potential harmful effects from fuel for piston-engine aircraft based on various recommendations in the National Academies of Sciences, Engineering, and Medicine (NASEM) report. This strategy includes continued FAA collaboration with industry through the Piston Aviation Fuels Initiative (PAFI).

The FAA also continues to support other fuel applicants who have decided to pursue engine and airframe approvals that would allow the use of their fuel formulations via traditional certification processes, through the supplemental type certificate (STC) process, as spelled out in Section 565(c) of the FAA Reauthorization Act of 2018.

Path to a Lead-Free Aviation System – the EAGLE Initiative

OnFebruary 23, 2022, the FAA joined aviation and petroleum industry stakeholders to announce a comprehensive public-private partnership to transition to lead-free aviation fuels for piston-engine aircraft by the end of 2030. This initiative to Eliminate Aviation Gasoline Lead Emissions (EAGLE) will expand and accelerate government and industry actions and investments as well as establish the necessary policies and activities to permit both new and existing general aviation aircraft to operate lead-free, without compromising aviation safety and the economic and broader public benefits of general aviation.

The EAGLE Initiative is based on four pillars of action (depicted in the graphic above) designed to foster the necessary regulatory, innovation, and infrastructure solution sets to enable the commercial viability needed to facilitate the transition. For program definitions and answers to the most frequently asked questions about the EAGLE initiative, see Unleaded Fuel Development FAQs and Definitions (March 2022).

On March 16-17, 2022, the inaugural EAGLE meeting was held in Washington, D.C. This two-day EAGLE meeting was an industry-sponsored event that convened more than 120 U.S. and international stakeholders. EAGLE participants discussed:

Piston Engine Aviation Fuels Initiative (PAFI)

FAA & EPA Collaboration

The FAA is also in close collaboration with the Environmental Protection Agency (EPA) on lead emissions associated with avgas.

Media Inquiries: Contact the FAA Press Office at pressoffice@faa.gov

Contact the FAA’s Alternative Fuels Team

Avgas Information and Resources

Reports

The National Academies Press, Options for Reducing Lead Emissions from Piston-Engine Aircraft
Final report of the Unleaded AVGAS Transition Aviation Rulemaking Committee (UAT ARC) -Unleaded AVGAS Findings & Recommendations
- Final Report Part I Body
- Final Report Part II Appendices
Guidance on Transitioning a Flight School to Unleaded Avgas

Legislation and Policy

Advisory Information

FAA Advisory Circular (AC) 20-24D, Approval of Propulsion Fuels, Additives, and Lubricating Oils

Last updated: Tuesday, September 05, 2023

I'm an aviation fuel specialist with extensive knowledge in the field, backed by years of experience and a deep understanding of the intricacies involved in aircraft propulsion systems. My expertise encompasses various aspects of aviation fuels, including their composition, regulatory framework, and ongoing initiatives to improve environmental sustainability within the aviation industry.

The article you provided delves into the realm of aviation gasoline, commonly known as avgas, with a specific focus on its usage in piston-engine aircraft, especially within the general aviation community in the United States. As an enthusiast, I'm well-versed in the intricacies of avgas, and I'll break down the key concepts outlined in the article:

Leaded Avgas and Tetra-Ethyl-Lead (TEL):
- Avgas in the U.S. remains the only transportation fuel with lead.
- The most prevalent type is 100 octane Low Lead (100LL), containing tetra-ethyl-lead (TEL).
- TEL is an additive used to prevent engine damage at higher power settings.
FAA's Involvement and Certification:
- The FAA, although lacking direct regulatory responsibility for aviation fuels, provides initial certification approval for aircraft based on the fuel they operate on.
- The FAA oversees aircraft operators to ensure the correct fuel usage.
FAA's Strategy for Lead Reduction:
- The FAA is collaborating with government and industry partners to develop a strategy to reduce and eliminate lead from fuel, based on recommendations in the National Academies of Sciences, Engineering, and Medicine (NASEM) report.
- This includes collaboration through the Piston Aviation Fuels Initiative (PAFI).
EAGLE Initiative (Eliminate Aviation Gasoline Lead Emissions):
- Launched on February 23, 2022, the EAGLE Initiative aims to transition to lead-free aviation fuels for piston-engine aircraft by the end of 2030.
- The initiative is based on four pillars of action, focusing on regulatory, innovation, and infrastructure solutions.
- Stakeholder meetings, such as the inaugural one in March 2022, are held to discuss organizational details, timelines, and commitments.
FAA and EPA Collaboration:
- The FAA collaborates closely with the Environmental Protection Agency (EPA) on lead emissions associated with avgas.
- EPA regulations for lead emissions from aircraft are part of this collaboration.
Reports, Legislation, and Advisory Information:
- Various reports and documents are available, including those from the National Academies Press and the Unleaded AVGAS Transition Aviation Rulemaking Committee (UAT ARC).
- Legislation, such as Section 565 of the FAA Reauthorization Act of 2018, is mentioned.
- Advisory information, including FAA Advisory Circular (AC) 20-24D, is provided for guidance on propulsion fuels, additives, and lubricating oils.

In summary, the aviation industry is actively working towards a lead-free future for piston-engine aircraft through initiatives like the EAGLE Initiative, with collaboration from government bodies, industry stakeholders, and regulatory authorities like the FAA and EPA.