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Wednesday, 29 November, 2023

Unleaded Fuel Candidate Advances into Next Stage of PAFI Testing

Washington, DC, November 29, 2023 – General aviation industry members of the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative are applauding the news of the first unleaded fuel candidate to successfully pass the most rigorous Piston Aviation Fuels Initiative (PAFI) initial detonation and 150-hour engine durability test phase, and continued progress toward an unleaded future.

The FAA issued the following statement earlier today:

The Federal Aviation Administration has approved the advancement to full-scale engine and flight testing of unleaded UL100E aviation fuel for piston-engine aircraft developed by LyondellBasell Industries/VP Racing. The UL100E fuel successfully passed a 150-hour engine durability test under the Piston Aviation Fuels Initiative (PAFI), a collaborative industry/government testing program. LyondellBasell/VP Racing UL100E is the first unleaded fuel to pass the PAFI 150-hour durability test phase.

“This is another important milestone for a safe General Aviation transition to unleaded fuel and for our goal to eliminate lead emissions by the end of 2030. The joint industry/government effort continues to make strong progress,” said Lirio Liu, FAA Executive Director of Aircraft Certification Service and Government Co-Chair of the Eliminate Aviation Gasoline Lead Emissions 

(EAGLE) government-industry partnership.

“LyondellBasell/VP Racing’s achievement marks an important waypoint on the path to a more environmentally friendly future for aviation fuel and demonstrates the progress we’ve made through our government and aviation community partnership. EAGLE celebrates this milestone and looks forward to more opportunities to recognize industry ingenuity and innovation,” said Curt Castagna, President of NATA (National Air Transport Association) and Industry Co-Chair of the EAGLE initiative.  

The LyondellBasell/VP Racing’s unleaded fuel will now move into the PAFI full-scale engine and airframe testing consisting of ten engines and eight aircraft, which is expected to be completed in 12-18 months. 

The PAFI program rigorously tests candidate fuels through various phases including evaluation of toxicology and environmental considerations, material compatibility, engine durability and detonation, and aircraft performance and operability. Information gained from the testing supports the development of an industry consensus ASTM International production specification. Once the thorough PAFI testing procedures have been successfully completed and an ASTM production specification published, the FAA will then issue a fleet authorization to safely allow use of the fuel. The goal of PAFI is to test, not produce, fuels that can ensure both compatibility and safety within the piston-engine aircraft fleet as well as commercial viability for deployment.

For more information about the EAGLE initiate, visit For additional background on FAA/industry establishment of EAGLE, recent progress, and PAFI, visit

For general press inquiries, contact Shannon Chambers at 703-298-1347 or

The National Air Transportation Association (NATA) has been the voice of aviation business for more than 80 years. Representing nearly 3,700 aviation businesses, NATA’s member companies provide a broad range of services to general aviation, the airlines and the military and NATA serves as the public policy group representing the interests of aviation businesses before Congress and the federal agencies.