GA Pilots Press Committee on Lead-Free Fuel

“We can’t buy 100LL fuel,” one GA pilot complained to the panel. “When can we have some alternative?” That question—and several others like it—drew robust applause among the audience of about 200 people attending a forum on the EAGLE initiative. 

“I’m not not going to put a date on it, but we’re working hard,” said FAA panelist Lirio Liu. “We’re certainly closer than we’ve ever been before,” said her FAA colleague Maria Di Pasquantonio. “We’re all working toward the same goal.”

The initiative—dubbed EAGLE, for “Eliminate Aviation Gasoline Lead Emissions”—debuted in February of this year. EAGLE executive committee members overseeing progress on the initiative represent a wide spectrum across the aviation community, including the FAA, Aircraft Owners and Pilots Association (AOPA), the EAA, the General Aviation Manufacturers Association (GAMA), the National Business Aviation Association, the National Air Transportation Association, and the Helicopter Association International.  

“There’s just a lot of misinformation swirling about that program,” said EAA Board chairman Jack Pelton at a news conference following the forum. “There are so many pieces to the puzzle.”

Although aircraft manufacturers and the FAA have been trying to solve the complex issue for years, it’s been made even more complicated from the economic ripple effects created by Russia’s invasion of Ukraine, now entering its fifth month. An international ban on purchasing Russian oil has increased volatility across petroleum fuel markets. 

The issue potentially affects the approximately 167,000 piston aircraft in the U.S.—and 230,000 globally— that require 100LL avgas containing the additive tetraethyl lead (TEL), according to the FAA.  

TEL raises avgas octane levels, which prevents knocking in high compression engines. Using lower octane fuel could contribute to aircraft engine failure, which is why TEL remains in use. 

For more than a decade now, aircraft manufacturers and the FAA have been working with the petroleum industry to develop alternative fuels that can eliminate engine knock without using TEL. 

Many pilots have critical questions that hinge on the initiative’s timing. For example, should GA airplane owners overhaul the engine on their aging high-compression aircraft—or should they wait for new technology and fuels to be developed first? That’s a high-stakes decision that depends on a huge, complex network of FAA regulators, fuel producers, and aircraft manufacturers. 

“We’re interested in a viable solution,” said GAMA vice president of engineering and maintenance Walter Desrosier. 

Panelists at Monday’s forum said it’s still unclear when stakeholders will be able to complete the necessary research and development of lead-free fuel and the engine technology needed to support it. Once that’s done, the program aims to smooth the transition phase, including production and delivery to airports. 

“Just for the manufacturers to produce it is a three to four year process,” said Pelton. AOPA contributor and former editor-in-chief Tom Haines pointed out that a fuel transition like this has never been attempted before in modern aviation history.

Stakeholders say their goal is to develop viable and effective unleaded high-octane fuel solutions for delivery to the GA fleet by 2030. Once that’s achieved, then the industry would sunset 100LL. Liu acknowledged that the program’s goal of 2030 is “aggressive.”

The EAGLE initiative includes four pillars of action:

1. Develop unleaded fuels infrastructure and assess commercial viability.

2. Support research and development and technology innovations involving potential engine modifications and/or retrofits that would allow high compression piston aircraft to safely operate with unleaded fuel.

3. Evaluate and authorize safe unleaded fuels with the goal of eventually transitioning to an entirely unleaded general aviation fleet. 

4. Establish any necessary policies based on evaluation from the EPA. Any eventual EPA regulations surrounding lead emissions from piston-engine aircraft would contribute to new FAA regulations regarding fuel components, engine modifications, and new engines that run on unleaded fuel. 

The entire industry has its work cut out for them. A key EAGLE goal includes identifying at least one unleaded fuel acceptable for the entire fleet. Another: mitigate potential impacts on the existing aircraft. “How many aircraft-engine combinations are there? Thousands upon thousands,” Pelton said. 

Pilots attending the forum—many of whom flew their aircraft to attend the event—expressed frustration about the issue, largely because it’s been ongoing for years, without apparent progress. GA pilot Lee Holmes, age 82, flew his Cessna 182 to Oshkosh this year—as he does most years—from Oklahoma City. “Getting rid of lead will probably increase our TBO—that’s time between overhauls—because the lead part fouls up our spark plugs.” 

Holmes wants the FAA to sign supplemental type certificates for the unleaded fuel G100UL. 

“I’m very passionate about this issue,” said Holmes, who was standing in the back of the venue holding placards saying, “All we need is for FAA to sign STC G100UL in 2022.” 

“We need it now,” he said. “This EAGLE program is going to take $100 million of taxpayers money, and it won’t guarantee anything.”

Despite being on the front end of a gargantuan task, the committee members expressed optimism for success. “There will be a transparent pathway,” GAMA president and CEO Pete Bunce said. With support from all stakeholders, “the FAA is going to get it done.”