Engine and airframe manufacturers are calling for greater transparency in the process toward eliminating lead from aviation gasoline so they can ensure the safety and reliability of the fuels for their products and customers. The General Aviation Manufacturers Association held a video news conference on Monday to give an update on the Eliminate Aviation Gasoline Lead Emissions (EAGLE) initiative and to unveil a new website. Representatives from industry, government and industry associations and those who make the products that will use the high-octane replacement for 100LL are anxious to test the four candidate fuels (General Aviation Modifications Inc. [GAMI], Swift Fuels, Lyondell Basell/VP Racing Fuels and Phillips 66/Afton Chemicals) but have not been able to get sufficient quantities to assess their suitability. “We have tested nothing to date,” said Textron CEO Ron Draper.
Draper said OEMs have to check the impact of the fuels on thousands of aircraft components that come in contact with the fuel, including all the gaskets, seals, liners and other “soft parts” in the airplane. “We desire more transparency,” he said. “We want to test the fuels.” Although some operational testing has been done, much of the testing to date has been done in the lab and the formulations and ingredients are proprietary in some cases. CubCrafters CEO Patrick Horgan also called for “general transparency” from the process.
Lycoming Senior Vice President Shannon Massey also urged access to all the specs on the fuels for the obvious impacts they could have on the myriad parts in a modern aircraft engine. But there are more subtle differences that need to be assessed as well, including fuel density. The weight of the fuel will influence the fuel controls and delivery systems and that might require adjusting those systems to ensure performance and reliability.
Lirio Liu, who heads up certification at the FAA, said the process is complex and there is also the issue of environmental suitability of the fuels. The agency has called on the National Academy of Sciences to assess whether the specific formulations of the four fuels will simply trade new emissions issues for the elimination of lead.
Two of the fuel developers have opted for a supplemental type certificate process to bring their fuel to market. GAMI’s G100UL fuel got STC approval for virtually all avgas engines last year and Swift’s unleaded 100R is expected to get approval this year said Liu. The other two manufacturers are going through the Piston Aviation Fuels Initiative (PAFI) and if either of those t are approved the FAA will issue “fleet authorization” that will allow their use in all gasoline aviation engines. The Basell/VP fuel is nearing the completion of its testing and the Phillips 66/Acton formula is set to begin testing. EAA Chairman Jack Pelton noted that only the PAFI route is practical for his members since STCs can’t be applied to homebuilts and experimentals.
While all these details are worked out, EAGLE members are stressing the need to maintain availability of 100LL until all engines are able to use a universally accessible unleaded substitute. According to Lycoming’s Shannon Massey, while many aircraft engines can use already-available unleaded fuels, more than half the engines in service must have high-octane fuel to operate safely. Many of those engines are on commercial twins and big singles used for cargo, commuter and other commercial applications.
AOPA President Mark Baker, who co-chairs the EAGLE initiative with Liu, said time is short to get this all sorted out. EAGLE has set a goal of 2030 to have an unleaded high-octane replacement for 100LL, and the EPA is expected to issue an “endangerment finding” on leaded avgas later this year, further ratcheting the pressure. “This is urgent,” he said, adding that the endangerment finding will give those who want to get rid of general aviation airports more ammunition. “We want to get a fuel to our members and to (EAA’s) members as quick as possible and get this off our backs and be good citizens,” he said.
Finally progress! Sure glad there’s a new website.
“Still Much To Do”
Yup – still more roadblocks to be created, hurdles to be raised, goalposts to be moved, and palms to be greased.
Color me cynical, but this all appears to be more delaying action.
– “We have tested nothing to date,” said Textron CEO Ron Draper. Really? according to GAMI, “Early in the development of G100UL avgas both Lycoming and Continental sent engineers to GAMI in Ada who evaluated G100UL avgas…. There was no objection raised by either of those two early OEM engine manufacturers to the performance of the G100UL avgas.” If no (more) testing was done it was for lack of trying – don’t show up, don’t test, just keep kicking the can down the road.
– “EAA Chairman Jack Pelton noted that only the PAFI route is practical for his members since STCs can’t be applied to homebuilts and experimentals.” Really? Since when do experimentals give a hoot about STCs? That’s the whole point of an experimental plane, the freedom to use whatever you want! Do you really think the guy that took the engine out of a Corvette and bolted it to the nose of his P51-wannabe is really going to be stopped by the lack of an STC?!
– “EAGLE members are stressing the need to maintain availability of 100LL until all engines are able to use a universally accessible unleaded substitute.’ Well, of course – must keep the money pump going going for as long as possible. Sure, unleaded avgas will be a new money pump, but owners of existing 100LL money pumps don’t know where to buy the new one yet, and, well, their current one is still working. If it ain’t broke, don’t fix it, right? And make sure no one else takes MY money pump away!
I’d like to know who is funding this EAGLE initiative. Or applying political/financial pressure to insure its formation and existence.
It could be a problem, yes, the lack of STCs for Experimentals. That’s because you’ll pull up to the pump and enter your credit card and the pump will say “Please enter your STC number” and you won’t have one.
It won’t matter that you don’t care about the lack of an STC. The pump will not give you fuel.
I’ve encountered 94UL pumps that asked for STC number OR N-number and would then dispense fuel. I guess the theory is that there’s a permanent record of a certificated airplane using the fuel, and if it doesn’t have the STC that will show up in the accident investigation. I hope it stays that way, i.e., pump first, ask questions later. But, it may not.
P.S. I would much prefer to see a fleetwide shift to 91 or 94 octane. The stuff they’re adding to these new unleaded fuels doesn’t sound like it’s going to be all that good for people or soft aircraft parts (from seals to composites including composite fuel tanks – and yes, I know it’s been tested on Cirrus tanks). We don’t need to be having another environmental threat to the fuel supply in 10 or 15 years (remember MTBE, anyone?).
Kirk, you know who is funding the EAGLE program. Your tax dollars in action. 🙁
“While many aircraft engines can use already-available unleaded fuels, more than half the engines in service must have high-octane fuel to operate safely.”
That’s not consistent with what I’ve always heard. I’ve always heard that most engines don’t need 100-octane, but most of the *volume of fuel* sold goes to the minority of engines that do require 100-octane fuel. So shouldn’t that read “While most aircraft engines can use already-available unleaded fuels, more than half of the fuel volume sold is burned in engines that require high-octane fuel to operate safely”?
That statement caught my eye as well. The stat I’ve often heard is 70/30 – 70% of the 100LL is consumed by 30% of the fleet. But the article also says “Most of those engines are on commercial twins and big singles used for cargo, commuter and other commercial applications.”
So if most of that 30% of the fleet are twins, then the number of *engines* that need high-octane fuel is much greater than the number of planes. I’m not seeing where 50% comes in, but it does come much closer to half the overall fleet.
For instance, let’s start with the 70/30 number. So, for every 100 airplanes, 30 of them require 100LL. For simplicity’s sake let’s say those 30 are twins. There’s still 100 airplanes, but now there’s 130 engines. And 60 of those engines need 100LL. 60 divided by 130 is about 46% of the fleet. Still not quite half, and not all of those 30 are twins, but I can see where they’re going.
So by counting engines instead of airframes, you get a much higher percentage of things that require 100LL.
It gets even better. From what I’ve read, while 30% of the fleet needs 100LL, that’s not technically very hard to change. By slightly reducing compression (change the pistons and/or cylinder heads) they could take 94 UL or even 91 UL. It would be accompanied by a few percent reduction in rated power (someone correct me if I’m wrong, but that’s what my few hours of research into this concluded).
However, the cost would be considerable, not because it’s difficult but because the changes would require STCs, which would cost a small fortune for every aircraft to be converted.
So we all live with 100LL fouling our plugs and valves (and killing a few pilots a year) and polluting the environment and helping to kill off our airports.
Also, that “few percent reduction in rated power” could make a rather large difference in the performance envelope of the aircraft, especially if it’s one with two engines.
Not doable for most non-turbocharged twins. Their single engine performance is already marginal enough, barely meeting certification standards. A slight reduction in power would mean those twins would be unable to meet certification standard for single engine climb performance. In single engine planes, a reduction in power would mean some of the planes would not meet go around performance standards. One of the reasons C172’s that have gross weight numbers at 2400lb or higher require flaps to be limited to 30 degrees.
No Turbo charged twins can have the same max power when water injection is used in combination with a lower octane fuel. The water injection only needs to be used during high power settings. Like engine outs or Max take off power.
Non Turbo charged twins can have the same max power when water injection is used in combination with a lower octane fuel. The water injection only needs to be used during high power settings. Like engine outs or Max take off power.
I note the comment on “environmental suitability” and trading one form of environmental impact for another. Did the bureaucracy do that with regard to promoting electric vehicles — or other alternate sources of power?
Yes. https://www.epa.gov/greenvehicles/electric-vehicle-myths
Yes. Turned out to be an easy win.
Interesting to wait and see what the EPA “endangerment finding” findings show,problay they factor in variables such as total volume consumed,etc.Maybe on a scale from,Extreme,Moderate,Low,Negligible
Whether anyone likes it or not it is highly unlikely that more than one unleaded fuel will eventually get carried by most FBO’s. If having multiple grades was economically feasible the old “red” 80 octane would have never been dropped by most airports 30+ years ago. I still haven’t heard how the liability issue is going to be handled. I don’t think the oil companies really care about avgas due to the low volume vs liability involved. Until the EPA bans leaded avgas, I’ll bet nothing will stop the stonewalling that seems to be happening now. My guess is Congress will have to pass a law changing the liability involved just like the change that was made before Cessna resumed production of piston powered planes.
Sure makes me glad that I can and do burn Auto fuel. Hope that will still be around for the next 20 years!!!!! Who knows Avgas might be the only fuel Anyone can buy in 10 to 15 years if the powers that be decide we all need to drive EV. Would be funny to see if it wasn’t so scary.