Testifying before the Environmental Protection Agency (EPA) on air-quality standards for lead, AOPA executive v-p of government affairs Andy Cebula warned that any immediate changes to current aviation fuel standards would have a “direct impact on the safety of flight and the very future of light aircraft in this country.”

He told the federal agency that the GA community is researching alternative fuels and developing certification standards for new fuels and engines. But he said that despite a decade of research and trials, there is currently no unleaded alternative for 100LL avgas that can be used safely by all piston-powered aircraft flying today.

On May 20, the EPA issued a notice of proposed rulemaking titled “National Ambient Air Quality Standards for Lead.” Through this NPRM the agency is seeking to tighten the current national ambient air-quality standards for lead.

“[Tightening] the national ambient air quality standards for lead, without a suitable replacement fuel available, would negatively affect the $150 billion general aviation industry, threatening a nationwide transportation system that supports smaller communities, agriculture, firefighting and medical emergency flights,” said Cebula. “Reducing the amount of lead in avgas is not a simple process. The EPA needs to consider the dramatic impact it could have on general aviation and the nation’s economy if it were to make immediate changes in the lead standard.”

Explaining that tetra ethyl lead is the only available fuel additive approved and proven to protect high-performance aircraft engines from detonation, he said other octane enhancers, such as ethanol, can adversely affect aircraft engines and systems. Current FAA standards prohibit the use of ethanol in aircraft fuel systems.

Cebula noted that aviation gasoline makes up only 0.25 percent of all petroleum products, while the nation’s drivers burn more autogas in one day than general aviation uses in a full year. That small volume, he said, means that only one fuel, suitable for all piston-powered aircraft, can be economically viable.

“A suitable unleaded replacement fuel is one that can be used in all existing and new piston-powered general aviation aircraft,” Cebula testified. “AOPA understands that for a small percentage of aircraft, this may require engine and airframe modifications.”