The US Environmental Protection Agency (EPA) has formally begun the regulatory process required by the Clean Air Act that could ultimately result in standards mandating the General Aviation industry’s transition to unleaded avgas.
The EPA has issued an advance notice of proposed rulemaking (ANPR) which is a key opportunity for the GA community to provide comment regarding this possible new environmental standard and into the development of a plan for identifying, evaluating, and ultimately transitioning to an unleaded fuel.
This is particularly important given the technical complexity and safety implications of removing lead from aviation gasoline since there is not a high-octane replacement unleaded avgas available today that meets the requirements of the entire GA fleet.
In the ANPR, the EPA recognised the complexity involved in identifying and safely transitioning to an alternative gasoline, stating, “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 also acknowledged that a joint effort will be critical in the likely case that 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 said.
The US AOPA, the Experimental Aviation Association, the General Aviation Manufacturers Association, the National Air Transportation Association, and the National Business Aviation Association have devoted more than 20 years of research and development to identifying a viable alternative to the 100 ‘low lead’ avgas formulation used today by most piston-powered aircraft.
The industry stakeholders say they are looking 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 issue of mandating the transition to unleaded avgas poses severe ramifications across the board for the GA industry, so here at Australian Flying we're keeping a close eye on these developments.
Image credit: John Absolon.
