The FAA has taken the next step toward its goal of transitioning to unleaded aviation gasoline (avgas) by the end of 2018, narrowing the field of potential replacement fuels to two for further testing. The agency selected unleaded fuel possibilities from Shell and Swift Fuel for Phase 2 of its Piston Aviation Fuels Initiative (PAFI). These fuels were chosen from the four that the agency initially selected for testing in 2014, which themselves were selected from 17 possibilities offered for the PAFI program.
Phase 1 testing, which was completed in December, included conducting basic fit-for-purpose and chemical property laboratory evaluations, six rig tests, materials compatibility testing, engine testing and a toxicity and environmental impact evaluation of the chemical components of the fuels. According to the FAA, Phase 1 data enabled companies to update their feasibility assessments and examine production and distribution costs, along with environmental factors.
Following this testing, the FAA selected the two fuels that would have the least impact on the general aviation fleet and on the fuel production and distribution infrastructure, the agency said. The next round of testing is set to begin this summer and run through 2018.
Data derived from Phase 2 testing will be used to develop an ASTM International product specification and clear the way for the FAA to authorize the general aviation fleet to use the replacement fuels. Congress appropriated $7 million for the PAFI test program, which is being conducted at the FAA's William J. Hughes Technical Center in Atlantic City, N.J.
“Government and industry are successfully working together to lower aviation emissions,” said FAA Administrator Michael Huerta. “We’re on track to have unleaded aviation gasoline fully evaluated and ready to be authorized for use by the general aviation fleet in 2018.”
The agency estimates that approximately 167,000 general aviation aircraft in the U.S. currently rely on 100 octane low-lead avgas. General aviation is the last mode of transportation that still relies on leaded fuel, making it a target for environmental groups seeking to eliminate sources of lead. Environmental groups have petitioned the Environmental Protection Agency and filed lawsuits to speed up the introduction of unleaded fuels.
“We’re committed to finding safe fuels that benefit the environment and our general aviation community,” said Transportation Secretary Anthony Foxx.
General aviation groups lauded the move to the next phase. “It’s important for general aviation to be ready to move away from leaded fuel, and [the] announcement that two fuels have been selected for further testing is another key step down that path,” said David Oord, v-p of regulatory affairs for the Aircraft Owners and Pilots Association. “The program is on track, and the candidate fuels are promising, which is good news for GA.”
“The long-term viability of the existing GA fleet and future of the marketplace depend on the success of this program,” added Experimental Aircraft Association chairman and CEO Jack Pelton.
General Aviation Manufacturers Association president and CEO Pete Bunce agreed, saying, “A successful transition from leaded to unleaded avgas will mean the continued safety and utility of the fleet, a reduced environmental impact and lower economic transition costs for our industry.”