The Environmental Protection Agency (EPA) has formally begun the regulatory process that may ultimately lead to standards mandating general aviation’s transition to unleaded avgas.
The EPA issued an advance notice of proposed rulemaking (ANPR), a preliminary step in the process required by the Clean Air Act for the EPA to establish standards for lead emissions from avgas. The ANPR gives the GA community an opportunity to comment regarding the possible new environmental standard and the development of a plan for identifying, evaluating, and ultimately transitioning to an unleaded fuel, several industry groups said in a joint statement April 21.
There is no high-octane replacement unleaded avgas available today that meets the requirements of the entire GA fleet, so industry groups’ input will play an important role in addressing the complexities of identifying and safely transitioning to an alternative fuel for GA aircraft.
“The Aircraft Owners and Pilots Association (AOPA), the Experimental Aviation Association (EAA), the General Aviation Manufacturers Association (GAMA), the National Air Transportation Association (NATA), and the National Business Aviation Association (NBAA) have devoted more than 20 years of research and development to identifying a viable alternative to the 100LL avgas formulation used today by most piston-powered aircraft,” the industry press release said. “The industry stakeholders look forward to continuing their work with the EPA and the FAA on establishing a realistic standard to reduce lead emissions from GA aircraft along a transition timeline which balances environmental benefit with aviation safety, technical feasibility and economic impact upon the GA industry.”
The ANPR acknowledged the difficulties of the transition. “Converting in-use aircraft/engines to operate on unleaded aviation gasoline would be a significant logistical challenge, and in some cases a technical challenge as well,” the EPA said.
The agency also acknowledged that a joint effort will be critical if, as expected, engine modifications will need to be developed and certified.
“Given the potentially large number of affected aircraft and the potential complexities involved, a program affecting in-use aircraft engines would need careful consideration by both EPA and FAA and the two agencies would need to work together in considering any potential program affecting the in-use fleet,” the EPA continued.