The Environmental Protection Agency (EPA) has formally begun the regulatory process required by the Clean Air Act that may ultimately result in standards mandating the industry’s transition to unleaded aviation gasoline (avgas). The EPA has issued an advance notice of proposed rulemaking (ANPR), which is a key opportunity for the general aviation 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, according to EAA officials, who note 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 recognized 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 agency also acknowledged that a joint effort will be critical in the likely case that engine modifications will need to be developed and certified. The EPA continued, “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 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. Association officials say they 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.
View the ANPR here.