A June 20, 2019, update from the FAA on the search for an unleaded fuel for general aviation reveals that the agency is looking for more fuels to test.
It also reveals that the FAA’s experience testing unleaded fuels — which includes engine, aircraft, materials, and toxicology — “has served to accentuate the extent of the challenge to identify an acceptable unleaded fuel for general aviation.”
The FAA’s mission is to find a safe unleaded avgas with the least impact on the U.S. fleet of more than 170,000 piston-engine aircraft.
While the Piston Aviation Fuels Initiative (PAFI) began in 2014 with 17 fuel formulations, just one remains — a candidate from Shell — and it needs “additional refinement” before it can successfully complete testing, the update reports.
“Test results of that engine testing have revealed that additional refinement will be necessary to support continuation and ultimately result in successful completion,” FAA officials said in the recent update. “Shell has indicated it is committed to additional R&D efforts to make those adjustments in order to result in a safe and viable unleaded avgas.”
During the first six months of 2019, officials at the William J. Hughes Technical Center added three fuels not previously part of the PAFI program into the testing program, “representing PAFI’s commitment to research and evaluate all candidate unleaded fuels.”
The FAA has put out a call to fuel producers developing high-octane unleaded fuels to bring their data to the FAA for evaluation at the William J. Hughes Technical Center.
“Those that pass the initial screening are invited to participate in a Cooperative Research and Development Agreement (CRADA) testing program in which producers provide additional resources and some funds for independent testing using PAFI developed standards and guidance,” agency officials said. “This is an ongoing activity necessary to support FAA and industry understanding and qualification for the authorization of any newly developed and proposed alternative fuels.”
“The FAA alternative fuels program for general aviation must be multi-faceted, ongoing, and supported by a collaborative government and industry process,” officials continue in the update. “The focus remains on qualification and authorization of an acceptable unleaded fuel and the safe transition to a more environmentally friendly aviation fuel.”
While the last update — in September 2018 — had moved the proposed completion date of testing from December 2018 to mid-2020, the newest update does not mention a possible completion date for the new testing.
“Despite this recent program delay, the PAFI program is essential to ensure a viable, safe, and economical fuel can be authorized by FAA for use by the existing GA piston engine aircraft fleet,” FAA officials noted.
“While it remains a challenge to identify an unleaded fuel formulation that will take the place of 100LL, the FAA and industry will continue to collaborate in executing an informed and safe transition of the GA fleet to an unleaded avgas once it is approved,” officials continue. “The PAFI Deployment Guide will eventually serve as a roadmap to successfully deploy an unleaded avgas, from the refineries to the wingtips of aircraft, including the essential supporting infrastructure.”
The FAA has identified nine sectors of aviation as being crucial to the planning and guidance before the new fuel is deployed:
- State and Federal Legislative
- Aircraft Fuels Regulations and Standards
- Manufacturing Capability
- Distribution System
- Airports
- Aircraft Modifications
- Communication & Training
- International Communication
- Safety Assurance
The FAA is developing a PAFI Deployment Guide that will provide specific action plans and responsibilities for each of the nine aviation sectors. It is “intended to be applicable to any unleaded fuel meeting the FAA requirements for approval,” FAA officials said.
“Identifying, testing and eventually authorizing a fleet-wide unleaded avgas solution remains a difficult challenge — but one that the FAA and industry are completely committed to,” the update concludes. “The FAA and industry members of the PAFI Steering Group continue to work with multiple fuel offerors to find the very best unleaded avgas solution for the GA fleet. The resolve to find an environmentally friendly solution has not waivered — regardless of the amount of time and effort it may take to achieve.”
The effort should be focused on spreading the availability of 94UL, a currently “listed” avgas. That fuel would be usable by over 80% of the fleet by most estimates. That 94UL is a listed avgas, it is usable with out an STC. Just as we can us 100LL in aircraft that were not certified with it, this to could be used in any that were certified with avgas of 94 or less octane. The 10-20% of aircraft needing 100 could be adapted at much less overall cost than replacing tet. lead.
More Bravo Sierra from FAA. This program was destined to fail and lo and behold it is failing. If one desires success in performing research, then one needs to design toward that goal, not some bureaucratic pie in the sky.
Yes we are screwed. If the FAA would allow electronic ignition and fuel injection, then we could have an entirely different outcome.
I would love to see an unleaded fuel become available, then my low compression fuel injected certified 150 HP engine would be very happy. Don’t think I will live long enough. Don’t have 50 years left on the old body.
The FAA identified 9 critical sectors of aviation as being crucial to the planning and guidance before the new fuel is deployed. Note that none of them were the end user!
PAFI is a government boondoggle designed to keep 100LL available as long as possible. In the mean time, those of us with older engines (a minority within a minority for sure) continue to have engine damage and accelerated wear from the excessive lead contained in 100LL fuel. So we continue using Autofuels or autofuel mixes. While available via STC, certainly not subject to the rigors of the refinement of 100LL.
This is one of the endless myth stories in aviation.
The one crucial factor that is being left out of this discussion is “affordable.” Private industry has spent a huge sum to get to this point where all but Shell have dropped out. Shell will need a return on its investment.
If the New Fuel is more expensive than 100LL ( at all ) the FAA will no longer need to show its concern for the Piston Fleet. Most of the remaining 170,000 will rot away in their tie-down spots.