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Search Continues to Really Get the Lead Out

Future aviation fuel candidates have yet to meet EAGLE mandate.

Aircraft being fueled
Aircraft being fueled [Credit: Shutterstock]
Gemini Sparkle

Key Takeaways:

  • Tetraethyl lead (TEL) was historically critical for high-performance piston aircraft engines, enabling significant aviation advancements like Lindbergh's 1933 flight and WWII aircraft, by preventing engine knock.
  • Due to its toxicity, the EPA issued an "endangerment finding," leading to a joint FAA and industry task force (EAGLE) setting a deadline of 2030 to find a universally available unleaded replacement for 100LL avgas.
  • Developing a drop-in unleaded replacement is proving challenging, with three main companies (GAMI, Swift Fuels, and LyondellBasell Industries) pursuing different regulatory and technical pathways, each facing issues like solvent compatibility or potential performance adjustments for engines.
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When Charles Lindbergh and his wife, Anne Morrow Lindbergh, embarked on their ambitious 1933 flight to survey over-water routes for airlines, they packed a secret weapon. The famous couple headed to some of the most isolated areas of the North and South Atlantic because that’s where the most direct routes from North America to Europe and South America lay.

Technology had come a long way since Lindbergh’s most famous flight from New York to Paris just six years earlier, and the heart of their new Lockheed Model 8 Sirius (named Tingmissartoq by a young Inuit boy in Greenland) was a brand-new Wright Cyclone SR-1820 radial engine, a state-of-the-art powerhouse that made 710 hp and set the standard for reliable performance at a time when powerplant technology was rapidly developing. 

Russ Niles

Russ Niles is editor in chief of AVweb. He has been a pilot since 1991 and joined AVweb 22 in 2001. He and his wife Marni live in southern British Columbia.

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