Thank You so much Russ for asking the BIG Question.
There was no organizations formed in the early 80’s when the FAA cancelled 115/145, 100/130 and 80/87. The FAA Part 135 aircraft I was working on and flying did not operate very good on this new “All Around” 100LL. The company had to change many of their operation practices and still had an increase in spark plug run-up failure regularly.
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Thank you for the fine irony and the good report in the tradition of Paul Bertorelli! But as all cartels are about big money, watch your 6…
In automobile class back in the early 80’s, i took apart 2 cylinder heads. One head came off a car that ran on leaded regular fuel. The other, the car ran on unleaded fuel. Upon disassembly, the head that ran the leaded fuel, other than being gunked up with crud, was perfect. I could have literally just cleaned it up and reused everything.
The cylinder head running the unleaded fuel, the exhaust valves were mico pitted. The exhaust valve seats, were just as bad. If not worse. Many of the valve seats, were pounded up into the head. A term called valve seat recession. And the intake valves weren’t much better.
I have no idea of the age and mileage of the cylinder heads i was working on. But i certainly saw the difference in the end result, between a vehicle that ran on leaded fuel, and one that ran on unleaded fuel.
Hopefully in the 40+ years of metallurgical advancements, we’ve come a lot farther. But i don’t want to be the first one to find this out, as an exhaust valve takes it last ride, as I’m climbing out of the departure airport…
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Like any commission, special council, study, or other government “initiative,” EAGLE will love the problem until the money runs out.
The EALGLE/ASTM process is starting to sound a lot like the ISO 9001 craze that hit manufacturing plants years ago. ISO 9001 started off as a method of quality assurance manufacturing. Many companies were urged (or forced) to adopt it to show customers they were producing quality products. However, it quickly became a paperwork and make work nightmare. All ISO 9001 compliance meant was that you were producing what your quality manuals said you were making. In other words, you make up the rules, then follow them, no matter how little sense they made. As long as the product that rolls off your assembly lines matched your ISO approved documentation, you were OK. The joke at the time was that a factory could produce concrete life preservers and as long as they met your quality manual specs, you were good to go. The life preservers were approved and you could stamp them with “ISO 9001” approved. Of course along with the approval came tons of paperwork, constant audits, and payments to some ISO 9001 approval agency. For many companies the overhead was just too much and the payoff too little. In fact many companies, like ours, considered the whole process a scam and of little use. EAGLE and ASTM is starting to sound a lot like ISO 9001.
It is important to understand the need for standards, and that is what the ASTM is creating - an industry consesus about how a product should be. With standards several producers can produce the product everywhere in the world and the result is availability and competition. GA-aircraft are not just produced for California, they are made for the entire world and aviation is also a world wide activity with border crossings.
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Isn’t there only 1 official EAGLE fuel, from Vitol (with Swift possibly trying to get added as another EAGLE fuel)? My understanding was that G100UL is not an official EAGLE fuel.
Russ, great article. It is always about money. It would be interesting to know why GAMI didn’t want to send a barrel of their invention to ASTM? Would also be interesting to know how much of GAMI’s flesh ASTM wanted in exchange for their approval? The FAA spent years and probably a billion of taxpayer dollars approving UL fuel. I have confidence that their STC is based on knowledge. Let’s move forward with the GAMI fuel before the corrupt system bankrupts the real inventor.
Agreed. ASTM standards, among others, provide worldwide input to industrial efforts toward materials that suit all, not just the minuscule targets we are attempting to placate. For all the inventive efforts of GAMI through the work of Mr. Braly and team, the real culprit in this is the STC process itself and the pressure it put on the FAA to approve an alteration devoid of any consensus standards. Pressure they did not want and had no business trying to approve in the absence of a consensus to which it could point should the recipe go sideways.
And by the way, Russ, those who casually explain that it’s too complicated for you to comprehend are of the same mentality as the researchers who brought us thalidomide in the 50s and 60s. Yes, chemistry is complicated, but it means nothing to the guy pumping 10 gallons of gas into a tank so he can fly to breakfast with the boys.
Avgas is a very profitable product; the established players don’t want to be replaced.
This is about money, and somewhere there is surely corruption.
As for the continuing nonsense that lead is good for engines; a glider operation in this area changed to MOGAS decades ago; the result?
At least fifty percent longer cylinder life, and no issues with exhaust valve sticking; “Morning Sickness” on the Lycoming 360 and 540 engines in their fleet of towplanes.
Lead is bad for engines and people;
we have viable replacements for 100"LL".
Stop the (fiscal) footdragging and bring it on; now!
My understanding is that it was the other way around - the pressure was on GAMI to show their methodologies of testing and validation were equal-to-or-better than the ASTM process. The FAA often allows for alternative methods to be used, so their approval of G100UL is not a unique one-off case.
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Keep up the good investigative reporting Russ. Speak the facts and force the critics to be transparent.
Amen. EAGLE, for all intents and purposes, has appeared for quite some time to be primarily to protect incumbent legacy fuel providers. AOPA, EAA, FAA, and all the other alphabets have done us a huge disservice under the umbrella of “safety”. In the meantime, GA gets a black eye in state after state, community after community. Like ADSB, what is needed is a national date certain tied to reality not to delay of game tactics; and incentives for refiners, FBO’s, and operators to get on board. This is the best way possible to start riding down the price curve on new fuel. We did this back in the '70s for automobiles so there is an existence proof. I’ve had a G100UL STC for my 182Q for coming up on 2 years waiting for EAGLE to stop dithering. Waiting to 2030, given what we know to be true is shameful. Topping the list for performative effort is AOPA with their twin engine test.
There are times I’ve wondered, perhaps unfairly, whether Flying Media Group will turn AvWeb into an outlet for industry and alphabet group press releases. Your piece here today, Russ, says to me that it hasn’t happened yet. Thank you for some true journalism.
Indeed, you are correct, the FAA does have that discretion, but it is generally employed in alterations for which elements of the change are known quantities, the sum of which eclipses the risk in the alteration. The FAA knows nothing about fuel (I don’t mean this in the literal sense, but in a collective measure of expertise.) and relies on a consensus when approaching new and novel concepts. Braly’s fuel is new and novel in that it is supposed to be a drop in, across the board unleaded fix to general aviation. If that were the case, the big boys would have done it years ago. But they know differently. They know lead is needed for air-cooled aircraft engines and they already know what aromatics contribute to the combustion process, some of which is problematic for anything but the most exotic valve and seat material.
The FAA was pressured by Braly’s stubborn refusal to accept shut-up and sit-down by those who said he can’t do it and it was he who stirred up Oshkosh and Sun-N-Fun. The FAA signed Braly’s STC under duress, but they signed. In essence, they caved in to the pressure. Now, they want EAGLE or PAFI or anyone else to help insulate them from blowback should the approval have to be rescinded.
They don’t “know” that lead is “needed”, and didn’t “know” that when they first added lead to avgas. What they did know back then was that lead was a pretty bad substance to use as an octane booster, but it was a quick-and-dirty solution that happened to work. I doubt any of them thought lead would be as long-term a solution as it ended up being.
I don’t buy the argument that the FAA was pressured to accept GAMI’s STC either. At least, not from outside forces. They don’t really have anything to gain through its approval. If they were truly forced to accept it, I would have expected Congress to be the one forcing them to approve it (as they did with BasicMed).
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A bureaucracy’s first and main goal is to ensure the continuance of the bureaucracy. It’s second goal is to expand. Once established they are forever.
Let med proceed with the ASTM process. Some of the coming ? UL 100 fuels containg ETBE as octane enhancer. ETBE for use in piston aircraft engines do indeed have an ASTM standard paving the way for a future ASTM UL100 standard containing this component. However this ETBE standard did not evolve by itself. ASTM formed a task-force to obtain the standard. I personally took the initiative to get it formed, and I also from own pockets of my company paid for all the costs to create the standard. I chaired the task force, my secretary was a former Cessna chief engineer Cesar Gonzalez (now deceased) and later in that position a representative from AIR BP in the UK. Personally I crossed the Atlantic about 40 times all paid from own pockets. Guess how many years it took to get the ASTM D 7618 standard for ETBE? Yes -ten (10) years. We started in 2006.
Also to note we had when we started a formal approval to use ETBE for use in fuels for piston aircraft engines issued by the FAA already Dec 1 st 1995. Mr Gonzalez provided Cessna technical reports in the size of 400 pages to support the work. I personally tested UL100 AVGAS in Switzerland year 2006 and flew myself as a pilot from Switzerland to Sweden on that fuel. The FAA issued a letter to the EPA Sept 26 2000 stating that the ETBE was the component to choose as agent to increase octane numbers in an unleaded AVGAS.
What does this tell us: It all takes time and many people have to be involved in order to get a safe unleaded AVGAS.
The FAA didn’t cancel those old 115, 100, and 80 octane fuels; market forces drove the refiners to stop making them (along with the old 91/96).
I do not wish to be argumentative nor do I want to start a dialog that strays too far afield, but I must disagree. GM first tested TEL in fuel December 9, 1921. Between 1922 and 1939, Standard Oil, Du Pont, Ethyl Corp, I.G.Farben, and the US Navy experimented with various recipes utilizing TEL as an additive to support new engine technologies in the face of declining fuel qualities. TEL at the time was considered a “Gift from God” in spite of injuring or killing many workers employed in the acquiring of raw lead materials and the refinement of the product. It’s not like oil companies just stumbled on this. Lead substitutes and additives as a concentrate have been marketed in Europe for the last 100 years and it is still available in some areas here.
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At the risk of exposing myself as a complete ass, I might add that the FAA has a Congressional mandate to use consensus standards in AC 23.2010-1, Chapter 5 and FAA Order 8000.376. The mandate is repeated at every reauthorization as a budgetary measure, taking advantage of existing experience and expertise when deemed appropriate.
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Well, not to burst your bubble BUT IT SHOULD NOT “take time and many people have to be involved in order to get a safe unleaded AVGAS.” The very fact there are so many “hands” involved in the process is what is making it a nightmare!!! AS for the ASTM, please reference an article in Aviation Consumer High-Octane Unleaded: Where Are We? - Aviation Consumer
It is the best description of the history of the search for a replacement to 100LL. It also provides a good “picture” of the current state of the Avgas fiasco!!! It showcases the infighting, stonewalling, waste of taxpayer money etc between the FAA, the fuel developers, along with the National Air Transport Association (NATA)
It also addresses the unneeded involvement of ASTM.
ASTM International was formerly known as “American Society for Testing and Materials”
Is NOT a FAA or government organization
Is an organization that develops and publishes international technical standards for a wide range of materials, products, systems and services.
Creation of a ASTM Standard Is a long drawn out process
ASTM standards are adopted, by being incorporated into many federal, state, and municipal government regulations
ASTM International has no role in requiring or enforcing compliance with its standards.
ASTM gets PAID by whatever agency that uses the standards they have developed The REAL REASON ASTM wants in on the fuel development!!
Also
An ASTM spec is not a recipe
It creates a spec that must be met! BUT, does not supply “recipe” for meeting the spec. SO, it requires that a series of laboratory tests must be run on every batch of fuel produced. CAN YOU SAY MO’ MONEY SPENT which raises the cost of the product!!!
This results in the “recipe” of a product being different between manufactures. IE** Chevron’s recipe is different than Phillips’ which is different than Exxon’s, etc.
So as you can see requiring an ASTM Standard may not be as desirable as one might think.
You mention ETBE which is also referenced in the article
ETBE (Ethyl-tert butyl ether) is ethanol based, but is classified as an “ether.”
what happens to aircraft engines when mogas with ethanol was used?
The rubber compounds in the fuel systems and engines fell apart.
At Oshkosh this year, data was provided that strongly suggests that the use of ETBE will create problems with diaphragms and other rubber components in our aircraft fuel systems.
Further, California statutes, make ETBE illegal for use in self-propelled vehicles. We didn’t see an exception for aircraft.
SO, how can ETBE be used in California
Currently there are 3 replacements for 100LL BUT, Does anyone really think that having 3 or more 100LL replacements to choose from is a good thing!!!
What about having different airports supplying 3 different kinds of fuel to GA being a good idea??
And, two of those choices CAN NOT BE USED in ALL GA Aircraft
Somehow, the bureaucratic nonsense needs to end. I for one do not think the industry needs to end up with multiple inferior products replacing 100LL due to bureaucratic ineptness!!!
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The truth is there is ONLY ONE true replacement for 100LL It is GAMI’s 100UL which is true drop in replacement! it can be used in ALL GA Engines with NO limitations!!! Unlike the other 2!!!
I agree on the footdragging!!! The FAA should make the best choice and get it to the market with no more delay!!!
So as exciting as the media releases are, the majority of the RHV STC purchases were “because they’re free, and I might need one someday…” And the Swift 100R at KSQL is only legal for 2 versions of 172’s, since FAA is withholding broader STC pending ASTM Spec release. And the GAMI STC kit came with warnings to have absorbent cloth towels available to immediately clean any spillage plus ceramic coating of painted surfaces near the fillers to prevent “damage”… It is good that George found a market at RHV for his inventory of G100UL, but the unleaded Avgas problem hasn’t quite been solved yet. Patience Grasshopper…
I think you are missing quite a bit here. The use of consensus standards is directed in as far as those standards:
Standards support the TC and STC process, they do not supplant it. Even when things are built to standards, their design often still needs to be FAA approved - look at just about every single mechanical and electronic component on your aircraft as examples.
The only exceptions where the part doesn’t need to be approved are for standard parts - things like fasteners. Those can be used without approval of the part, but how it is used and where it is used still needs FAA approval.
Where no standard exists (like for 100LL replacement) then the ONLY approval process that exists is via the TC or STC process. Full stop.
Wow ! Best as I can understand having FAA approval is only part of the process of bringing a new aviation product to market.
For many years there was an unleaded car gas called Mogas (Petersen STC) widely available for most 90 octane aircraft engines and that has now disappeared except in Alaska where Premium car gas is 92 octane and ethanol free.
Seems to me that a simple option has been replaced by some very complicated alternatives !!
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“Isn’t that what everyone wanted?” The answer to that question, posed in your sub-head, is: NO!
Because those two “competing” fuels are not, according to their respective manufacturers, mixable with one another. They can both be mixed with 100LL in any proportion (good), but not with one another (bad bad).
So, two airports roughly 8 flying minutes apart will be selling fuels that can’t be used in the same tank. Fantastic.
Also, it should be emphasized, G100UL has an STC covering every fixed-wing airframe and spark-ignition engine in the FAA registry, with expansion to rotorcraft coming shortly. Swift has an STC covering two (2) aircraft, neither of which requires 100 octane fuel in the first place, as you noted.
As someone who bases an aircraft at San Carlos that can’t use 94UL and isn’t on the G100 STC, I’m disappointed to say the least.
I have seen stated from many sources that 75% of the GA fleet can run on that same mogas, at a price point 1/2 to 1/3 the cost of these new UL fuels, and the benefits of decreased maintenance and increased engine longevity.
If the California legislature is actually concerned about getting the lead out, why haven’t they made an allowance in the “all gas must contain ethanol” decree to allow airports to sell this fuel?
Why is virtually nobody agitating for this extremely easy partial solution affecting a super majority of piston aircraft owners that will have the added benefit of helping increase the GA population through reduced operating costs?
That ratio at my little uncontrolled home airport is probably closer to 90%. There are 2 tanks and a fuel truck with 100LL. They could easily use 1 tank for mogas with no ethanol as sold in Alaska, keeping another tank and the fuel truck for 100LL, were they allowed to purchase and sell it by California law.
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And another thing, the mogas is fungible (can safely mix with) with 100LL.
Airports with a single fuel tank can continue to sell only 100L.
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Lots of things to unpack here today. Thank you, Russ, you have done an excellent job of keeping us all appraised of both the progress and the lack of progress on this front. Equally valuable, you provide us all with a forum to jump in and set the world straight - even though the majority of us are not fuel chemists either (leaving the door open in case I am the only one who’s STEM education is on par with Russ).
I was not involved in aviation back when 100LL became the “go to” fuel, but my training back at the turn of the millennium made clear what clear, red, green, and blue fuels were, and to pay attention that what went into my tanks was what I expected. Based on this, I would assume that not seeing those fuels at every airport doesn’t mean they were legislated into oblivion, but simply became less economically viable over time. It seems we unilaterally agreed to reduce the lead content at some point (thus the low-lead moniker), but I suspect that this is the first time we are intentionally creating a one-size-fits-all unleaded fuel for GA as a whole.
We have had unleaded aviation fuels for quite some time, but 100LL has dominated ever since I can remember. That would suggest that in spite of spark plug fouling (and being quite toxic) TEL must have some redeeming quality that is difficult if not impossible to find in equal degree elsewhere. To my understanding, the magic is not simply that it prevents detonation at this high of an octane, but that it produces a very smooth and consistent burn front as the flame propagates through the cylinder which is relatively gentle on the engine considering evenly distributed acceleration and evenly distributed heat. Of equal importance, it achieves this with nothing more detrimental to the engine itself than yucky (industry term) lead build up on the spark plugs.
In the search for a replacement fuel, we have three requirements. The first two are simple and straight forward: (1) 100 octane, (2) no lead. The third requirement is a little less clear: “whatever you do to achieve the first two items, it can’t have any side effects that are bad or unexpected”. This includes (1) shouldn’t cost more, (2) don’t degrade or interact with seals, gaskets, hoses and the like, (3) don’t cause parts on my engine to wear, (4) don’t make concentrations of heat in my engine, (5) stay fresh in my tanks and my carb literally forever. And (6) at least 100 more things that I am not smart enough to foresee. We’ve been told that the new fuels are everything we would ever hope for, but we have learned in recent years to be skeptical of the “experts”.
Whatever the “industry” chooses to go with, I will be stuck with. My ship will happily run on low octane, unleaded fuels, but it has only ever had 100LL in its tanks because I fly coast to coast and airfields that offer anything other than 100 low lead are few and far between. When the new and improved wonder gas is officially adopted, it will completely replace 100LL, and it will likely replace the lower octane fuels as well. Call me a nervous Nelly, but I believe in the maxim “The monster you know is better than the monster you don’t know”. As much as I want unleaded fuel, what are we replacing the TEL with, and will that new something turn out to be a monster in it’s own right? Only time will tell, and I am a proponent of taking all the time we have been given.
I don’t believe that EAGLE’s purpose is simply to see one or two unleaded high octane fuels reach the market. The goal should be to shepherd in the best replacement fuel we are capable of developing. Right now, 100LL still dominates across the country, and the amount of alternative fuel sold thus far isn’t even enough to taxi our fleet of GA aircraft to the run-up area. We have a long ways to go.
I believe that ASTM certification is important. It isn’t that the ASTM people are all knowing and will pass judgement on the formulation. The ASTM process allows the industry stakeholders (fuel manufacturers, engine manufacturers, aircraft maintenance shops, owners and pilots) to participate in creating a consensus criteria for the fuel and its manufacture such that any supplier can then be held to a consistent standard for formulation, performance, purity, etc. GAMI will not be the sole manufacturer or supplier of the new fuel for long (assuming it goes that way), and we want to guarantee that every “brand” of Avgas is the same as every other in formulation and performance.
I am happy to see both alternative fuels finally being sold. We need more exposure to these fuels than what we have seen so far. The FAA has approved an STC for GAMI’s fuel which was tested to their satisfaction, but I am unclear on what that entails. AOPA flew a single aircraft with GAMI fuel in one of two engines for a year. A large flight school used unleaded 94 octane for an extended period of time and then opted to return to low lead. Beyond that, I know very little about just how suitable these fuels are in certificated engines, and much less in my non-certificated Jabiru engine. After a million gallons have been consumed (rather than 1,000), we will start hearing about different people’s experiences with less than ideal engines, less than ideal test beds, and less than ideal engine management.
We still have six years; we should use every one of them to continue to assess, tweak, improve and reassess before we get into bed with something that we will have to “like it or lump it” for a very long time after.
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Why have a simple solution when complicated alternatives can be developed ?
Automotive engine heads were improved, using materials from high performance engines was one way.
Owner of old muscle cars stick to high octane gas, which is available in some jurisdictions such as BC, where Chevron and Co-op sell a 94 octane without ethanol and AFAIK without lead. BC law only requires an average minimum ethanol, so using a bit more in lower grades facilitates not using any in the highest grade.
There are additives of course, and racing fuels.
I don’t know what the Martin Mars was using and will in its last flights, years ago they either flew back to Sproat Lake at night for refuelling and maintenance, or had a road trailer with needed high octane fuel. (As in Fort McMurray AB or the reservoir in south TX from which it fought fire in northern Mexico. With a trailer for maintenance and parts.)
(Hawaii Mars has made its last flight, to a museum at YYJ.
Philippine Mars is in the water under power, being readied to fly to a lake in AZ then transported on land to a museum in Puma AZ. Forecast to depart on November 18.)
With no idea of the age or mileage - or, presumably, how the engines were treated - why did you assume that the lead was a factor in their condition?
Because i had no other theory. The cylinder heads of the unleaded fueling, were clean and pristine inside. Although severely pitted valves, seats, and sunken into the units.
Even though the leaded fueling heads were crudded up pretty badly, upon cleaning and inspection, they were basically in perfect condition and shape.
I didn’t see any evidence of either sets of cylinder heads being out of air / fuel ratios. Neither looked like they were running too lean, nor too rich. So my best guess was that the lead in the fuel prevented any damage.
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These issue were solved a LONG L:ONG LONG time ago. I have run Four engines Past 400K miles on regular unleaded. The need for hardened seats was determined in the late 1960s. If there was pitting and valve recession then those engines did not have satellite or equivalent materials for the valve seats.
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Actually, 94 octane isn’t high. My father told me that back in the late 60’s-early 70’s, 95 octane was the norm for leaded regular fuel. And the premium leaded fuels were between 100-102 octane.
And when one considers 130 octane aviation fuel, which i don’t think is available anymore, that really puts it into perspective.
When i took those engines apart, it was the early 80’s. So yes, perhaps the engine didn’t have the hardened valves and valve seats.
I recently retired my Pontiac with 263K on the clock. No issues with the engine, and it always had unleaded fuel in it too. I was hoping to hit 300K, but the need was dire for a replacement.
That’s true, but not for the reasons people may think.
The damage was likely due to too low an octane rating, not lack of lead.
When lead was added to gasoline, achieving the octane rating posted on the pump was easy. In fact, the gasoline being dispensed often had a higher octane, sometimes 1 or 2 points higher. So an “87” octane gasoline was really “88” or even “89”.
When lead was banned it became more difficult for refineries to meet, much less exceed, the posted octane. So what was once “88” or “89” is now exactly “87”, or even “86.9”.
The result was cars that formerly ran fine on “87” (which was really “89”) were now experiencing light detonation (“pinging”) far more frequently. Which can cause valve damage and valve-seat recession.
The UND experiment with unleaded avgas bears this out. First off, they didn’t use 100-octane unleaded avgas. They were using Swift’s 94UL with six points less octane. The engines they used are relatively high-compression (8.5:1) with advanced ignition timing of 25-degrees, both typical indicators of the need for higher octane. Originally certified for 91/96 avgas, they now show 100LL on their type certificate. In effect, they were being run right at the limits on 94-octane and some engines didn’t make it.
(as an aside - the Continental C-85, C-90, and O-200 engines like those found in Cessna 150s, Piper Cubs, etc. have a compression ratio of only 7:1. Their octane requirements are minimal. Those engines have been happily burning unleaded mogas for decades. Yet no one talks about a wave of valve-seat recession in those engines).
And don’t forget the addition of electronic ignition, knock sensors, lambda sensors, and all of the other modern stuff that prevents detonation. Too bad, but we don’t have any of those systems in our aircraft.
This is the crux of the entire matter. As @goldsternp says it plainly. Why simple when we can have complexity?
Transportation fuel is a means of storing energy in a very dense fashion, namely combustible/flammable liquids that turn into mechanical energy by converting the stored energy into heat. That is, we burn them.
It is or should be a commodity. That is exactly how transportation fuels work for automobiles, boats, ships and locomotives. Yet, none of these have a single fuel that meets all requirements: cars have octane requirements varying from swill to super. Same with marine gas engines, others use diesel type fuels which have no lead, by the way, and if steam ships still are around, they can use anything that will burn from coal to oil to wood, as long as it gets hot enough to boil water,.
This is the core matter: gasoline is a commodity item used in large quantities with a very mobile fleet. We also have very strict limits on fuel reserves for flight.
The problem I see with the STC issue is that aircraft leave the local airport pattern to actually be useful for transportation, will ultimately end up somewhere, needing fuel and not have the STC for brand X fuel, and although it may work just fine, cannot legally put it in the tanks.
It is purely absurd that an STC exists for every airframe and engine pair and is required. If the fuel is safe, then fine, amend the primary TC or fuel specification to include the fuel being offered. Then it is restored to what it is: a commodity to store energy in liquid form to make a propeller turn and move the airplane.
It is even more absurd that I have to have a fuel STC for brand X, Y, Z, …,
If I wanted to invest in the development of a fuel, and pay for the R&D costs, I could have easily bought stock in the company (if it offered it) and waited for the return after sales commenced. Instead, I’m being told I have to pay for the R&D cost of a commodity which should be making enough money to repay the developer for its R&D costs which have already likely received substantial tax incentives, aside from the fuel initiatives through the “universal” STC.
Can you imagine the nightmare if this same thing happened in 1971 at the local Shellgas pumps? Standard Oil never had it this good.
It seems GAMI doesn’t want to go through ASTM testing in fear it will reveal their secret new avgas formula. Surely I am oversimplifying but why not simply patent the formula, go through ASTM testing, then sell the rights to produce the patented formula? GAMI gets their money, G100UL can be made by many producers, and shipping/tanking issues follow industry standards.
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GAMI’s fuel is patented, however as alluded to above, there are warnings about cleaning up any fuel that makes contact with paint immediately. There are a lot of smart fuel manufacturers who have said the problem is difficult to get something that matches 100LL and all the avgas requirements. There’s likely a reason that they did not pursue fuels with similar contents to G100UL previously.
To all those pushing MOGAS, it isn’t a slam dunk. The shelf life of MOGAS is shorter than AVGAS. That’s one of the numerous requirements to be met here. Vapor lock is another issue.
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Uh, fact-check: GAMI has detailed inappropriate requirements in the ASTM standard, and gaps. Read GAMI’s web site thoroughly, FAQs for example.
I have the impression Swift also wants changes.
I am disgusted with people who think they can fly airplanes but have a conspiracy theorist epistemology.
Yes, many crash, such as the person who departed a runway that did not have lighting, was advised not to but proceeded anyway - to death of he and pax.
MOGAS may not be “slam dunk” but Peterson mogas STC’s are based on no/low risk. Can easily be checked with a vapor pressure tester. Vapor lock is not unknown even with 100LL. Shelf life for avgas seems to be 12 months while premium car/mo gas is 9 months which is hardly an order of magnitude better. In Alaska, premium unleaded 92 octan car gas is around $3/gallon while 100LL is $8.00. That’s a compelling difference. !
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Not all aircraft can run the lower octane Mogas, and try getting non-ethanol mogas in California… and it’s still a major alteration (i.e. STC) to the aircraft.
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That’s true but but according to EAA, 65% can; that’s a lot. The Petersen STC seems to be under $500 and although it is called a “Major alteration”, it is only a piece of paper.
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That’s like UL94. And for comparison, an STC for UL94 is not required for many aircraft that were approved on lower octanes.
That is not universally true. Their website (if you read it carefully; they don’t exactly make it obvious at first glance) even says that some alterations may be required. In the case of the PA28s, it requires new fuel pumps if I recall correctly. There are also some other caveats to be aware of too, so it’s not “just a piece of paper”.
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Further on the ASTM route:
The ASTM standard for ETBE secures that a fuel will have < 1 % of ethanol in the final blend. It is the same maximum ethanol content as is approved for the current 100 LL.
I doubt it is correct that ETBE is banned in California. Can someone verify please? Otherwise would not the PAFI project continue their work on such a fuel and not the world largest producer of ETBE Lyondell be involved in the AVGAS process.
Myself I am living in Sweden on the other side of the Atlantic.
When a fuel is blended such as 100 LL only approved components may be used. Novel components used shall in their turn have an ASTM standard. In that way a consistence is guaranteed. Then a single components could meet the ASTM standard but also exceed the requirements, for example being more pure. Thus not all 100 LL fuels for example are the same.
My back-ground is in the pharmaceutical industry. The path to obtain a safe unleaded AVGAS very much looks like the way new pharmaceuticals are released to the market.
The time line for bringing a new pharmaceutical product onto the market is usually 10-12 years so the time-line I indicated for a novel AVGAS without an existing ASTM standard is not out in the woods.
The individual CBIXBY indicates that I am in a bubble and this is correct . My bubble is green and I personally have the favor in the AVGAS world to design, produce, distribute and fly on it. So the ASTM here has been my help in Sweden. I introduced unleaded AVGAS 80 in the year of 1981 with nationwide distribution. Even the Royal Swedish Airforce used it for their aircraft. This was possible because the ASTM standard D910 at that time contained AVGAS 80 and a foot-note stated that unleaded AVGAS was permissible. When I designed the unleaded AVGAS 91/98 also the ASTM D910 standard helped me – because the standard did only stipulate a maximum amount of lead – no minimum value. The Hjelmco AVGAS 91/96 UL was released in the year of 1991 and approved the same year by the Swedish Civil Aviation Authority. Year 1995 it was recognized by engine manufacturer Lycoming covering a large number of their piston aircraft engines. This fuel is now the dominant AVGAS in Sweden and has about 80% of the total AVGAS annual volume in the entire country. Later on the ASTM here assisted and created standard D7547 where it now resides as UL94 – so UL94 is not a US product of origin. So the fact is that we have continuous production and use of unleaded AVGAS in Sweden thanks to the ASTM for more than 43 years and we have no technical issues.
I developed a high octane unleaded 100 octane AVGAS during the years of 2005-2006. The fuel was tested in Switzerland by the Swiss civil aviation authority and the German DLR (similar to the US NASA). Formal reports in the range of many hundred pages were published primarily on its environmental qualities, exhaust components and particle sizes. The fuel itself is safe for the engine.
But at that time I realized I had to incorporate a new high octane component, ETBE, for which there was no standard and the ASTM helped to bring such a component standard just for a fuel for piston aircraft engines. That standard was approved year 2016. But still there is no standard for a finalized fuel containing ETBE. This work is still going on and the competent people of the FAA in Atlantic City are involved in this project which is called PAFI to verify that novel components used are suitable for the engines and aircraft out on the market.
To summarize: Be glad that we have the ASTM and that industry takes the time and money and works in the favor to bring a safe fuel for your use to the market and which will allow competition among component and fuel producers to have such a fuel available wherever you will fly in the world and at the best available prices.
As a foot-note: yes an ETBE fuel even if reaching 100 octane unleaded may not satisfy all piston aircraft engines out there at a reasonable cost per gallon. For them there is a solution – water methanol injection. Such systems are made in the US and certified and they have a long story of success from the second World War. Cost wise for the GA-market this solution will probably be the most cost-effective. An overall majority may operate on a cost effective fuel at best available price, the other aircraft can use the same fuel but have to make an investment in their air-frame.
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Lars,
George Braly.
The California regulation states that neither MTBE nor ETBE may be used in any fuel for any “self-propelled motor vehicle.”
Maybe there is some way “around that” - - but it is an “issue” that the many PAFI / EAGLE people have chosen to ignore.
As far as “methanol - water” injection is concerned - - from 1) a certification point of view ; and 2) from a practical airport “logistics / availability” point of view - - the widespread fleet deployment of that “solution” is a complete phantasy.
There would be an impossible number of practical issues to be overcome, such as, airplane make/model specific “re-writes” of the existing FAA Approved Flight Manual Supplements. That along could keep a couple of FAA DERs with flight test and engine-powerplant “authority” busy on a full time basis for a year or more doing nothing but drafting that language and validating that on those individual make/model aircraft.
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You are correct for PA 28-160’s and above but not below where the STC is a piece of paper. Pieces of paper are a necessary evil of life but have more importance to some and less to others. For me, the least complicated way to obey the rules and do the job properly is preferred. Those who feel more comfortable with complications are welcome to take that route. 9000 TT, SMELSES, COMM., A&P/IA, M.Sc. CE, MBA 84 and still flying.
That’s interesting ! So the 30% that can live with a simple option will be forced to go complicated to help support those who can’t go simple ? Not my preference for “foreign” aid. I would want the gas sold to the upper 70% carry a surcharge to subsidize the extra cost of my having to buy 100UL instead of Mogas. Thank you for your gift.
It’s certainly understandable why there would be confusion on this issue. It’s a matter of defining the terms, and deciding what those terms will show. What’s needed is a Sustainable High energy Interim Transition. So the question is what will a Sustainable High energy Interim Transition Show?
For me a vehicle is a vehicle and and aircraft an aircraft. In my country a vehicle can never be a traditional aircraft - but there are flying cars out there so this is perhaps not the final word about ETBE in California?
For me the logistics with water methanol is no big issue. We have a number of aircraft made in the US that rely on anti-icing and de-icing based on fluid de-icing using ethylene glycol or isopropyl alcohol. I have had these components in gallons in my hangar for a PA-30 and de-icing of propellers. Nothing says that not the same logistics can be done with water-methanol. FBO:s should also not have the problem to assist here if you are en-route.
There are STC:s out there on water methanol injection systems for GA-aircraft for example such as Beechcraft Baron.
Petersen Aviation in Minden NE owns such STC:s I think. Such a STC allows 100 octane aircraft engines to operate on even autofuel with low octane. Typically water methanol injection gives you about 12 aviation octane. With an ETBE AVGAS having 100 octane the additional 12 octane will serve basically the entire fleet that needs more than 100 octane.
There could also be other options – GAMI worked long time ago on their PRISM system, with variable ignition timing. My 91/96 UL AVGAS/ UL94 (which is not an ETBE fuel) was tested by GAMI some 20+ years ago and with their PRISM system on a Lycoming TIO540-A engine. With everything on red in their test-cell the engine did not detonate. It was all observed by among staff from the AOPA and the AOPA-Pilot had an article about it.
I would not be surprised if others engineers with piston aircraft engine manufacturers in the US have worked on this issue. Look at the Lycoming iE2 which states it will work on UL100.
ETBE fuels could also get more than 100 octane but then an efficient scavenger is needed for the additional amount of MMT. MMT is a metal that here works as an octane enhancer. Such efficient scavengers exist outside the US.
In Europe it seems to be we will be allowed to use 100 LL until 2032 so there are another 7-8 years available to refine fuel formulas.
Lead is still the cheapest way to obtain octane numbers - which is appreciated by the GA community.
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“For me a vehicle is a vehicle and and aircraft an aircraft. In my country a vehicle can never be a traditional aircraft - but there are flying cars out there so this is perhaps not the final word about ETBE in California?”
Lars, maybe that is your definition of a vehicle.
But Merriam-Webster would disagree:
Definition “vehicle”
That makes it pretty clear. Do you agree ?
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To adopt Russ Niles paradigm for this editorial, I am just a small town kid who grew up nearby on a ranch. I only have about 56 years of flying experience. And I have only been doing FAA Certification for just 29 years.
I designed and operate one of the worlds most technologically sophisticated aircraft engine test facilities, but everyone should ignore that.
So I may not have a full understanding and appreciation as to just how simple it would be to make my high compression (8.7:1) turbocharged engine operate on 80-90 octane mogas - - using water-methanol injection.
But there would have to be enough of that water-methanol fluid on board the aircraft to operate continuously for 4.5 to 5 hours to support my Bonanza, because it cruises at 75% + power, and would detonate to destruction on mogas (without the methanal-water injection) in about 60-90 seconds.
Then, I am not sure what kind of storage tank there would have to be, nor where it might be located in that airframe. Rumors are that the methanol is pretty hard on a lot of traditional fuel wetted materials.
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Dropping the “humor” - -
What Lars is proposing is not a realistic solution and the physical alteration to the engines and airframes to implement that “solution” would rival the cost of an engine overhaul to modify each aircraft.
My $0.02 for the day.
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One of the few good things about getting old is that in many instances, you’ve seen it all before. All of the arguments against unleaded fuel just being impossible for certain engines were used back in the early seventies 70s when it was first proposed that tetraethyl lead be eliminated from automobile fuel. Amazingly, despite all of the cries of “it just can’t be done”, here we are with millions of cars running on unleaded fuel including those few remaining with air cooled engines. Where there’s a will, there’s a way.
English is not my mother tongue - but I refer in defintions to US law
18 U.S.C. § 2311. Anyone can Google.
Petersen Aviation has an STC issued by the US FAA for water methanol injection in aircraft. I trust the Petersen STC in the same way I trust the GAMI fuel STC .
Yes there will be a cost for such an installation but if the end might be a fuel several dollars cheaper per gallon with world wide availability than another fuel an aircraft owner will have to make a calculation during the life time of the engine and/or the aircraft. The PA-30 Piper Twin Comanche I referred to had the anti-icing tank and equipment on propellers installed as an STC several years after the aircraft was built. When I researched to install a water methanol injection some 12 years ago for my then PA-31 Piper Navajo - the cost was about USD 10.000 per engine. The pay off time for me at that time was about the half life of an engine between overhaul or about 3 years. All subsequent years after I would have saved a lot of money. However I did not make the investment - because my new UL100 fuel combined with an intercooler (FAA STC) would have given me the same capability.
…
At the end - this article was about the ASTM. I trust them because they have made Sweden to run on ASTM approved unleaded AVGAS for 43 years. It was so easy to get Civil Aviation Authorities, engine manufacters etc to go along when I as a producer of unleaded AVGAS was inside the ASTM standard D910 which by the way is the same standard where the AVGAS 100 LL resides.
Lars,
You are citing a federal criminal statute (18 U.S.C. 2311).
That federal criminal statue is unrelated to the civil regulations in place in California.
The regulations in California will be interpreted by the California State Courts.
The California Courts are not going to go to federal criminal statutes for definitions.
Based on some direct professional experience with similar “statutory construction” issues, it is nearly certain that the California Court would just rely upon a simple dictionary definition, such as the one I quoted in the earlier message.
And, again, there is no cruise power setting for a Navajo TIO-540J2B or J2BD engine that can operate free of detonation on autogas. In fact, my direct testing of 96.5 MON unleaded avgas on that specific engine demonstrates that it detonates at those power settings on that fuel.
Therefore, in order to operate free of detonation at typical cruise power settings, the methanol-water injection would have to operate continuously.
Not intermittently.
That would require a rather large storage tank and room to put it. That would then compromise the useable load of the aircraft and/or the range of the aircraft.
Everyone can have a different opinion - - but my judgment, based on hard data from actually testing that engine on unleaded fuels is that any solution other than high octane avgas is not visible within the know and deployable technology.
Even a highly sophisticated electronic ignition will not be sufficient.
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Mr. Braly, first, thank you for your comments on this editorial. It is always beneficial to hear from people who are well versed in such topics to present clear and concise data about how things actually work. I do have a question for you. I have visited your facilities in Oklahoma and you were good enough to demonstrate the operation of your engine test cell for those of us present. I also know that you have conducted operational testing on various fuel formulations to determine their suitability for aircraft use. Have you ever had the opportunity to test the 100 octane unleaded fuel that is sold in Sweeden as a substitute for 100LL? I am curious whether that fuel would actually be a viable substitute for 100LL in high performance engines like the TIO-540J2 you referenced, or whether it would be similar to fuels such as the Swift R100 that is limited to certain lower powered engines. I agree that requiring any of the US GA fleet to make modifications to their engines or airframes, such as water/methanol injection is totally outside the scope of the PAFI/EAGLE mandates. Their charter is to identify a DROP-IN replacement for 100LL that does not require any modifications of the fleet. At this point, it appears that yours is the only unleaded fuel to satisfy that critical requirement. Thank you.
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We DO have some of these systems in our aircraft. This 40-year A&P/IA has run EIS in my certified aircraft for thousands of hours. Its high time to change the hardware, But Lycoming and Continental are dragging their feet, and the airframers are not demanding it like they should. If Lycon would make the changes, we wouldn’t even need the 100 octane. The automotive industry has proven that over 5 decades. There is nothing about altitude that requires high octane, and the other needs for it can be eliminated by compression ratio reduction and/or ‘those systems’ that you reference.
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I agree on your Chieftain engine analysis. So compression ratio reduction COMBINED with smart EIS/intercooler/prop-efficiency-improvement/new Piper performance charts/etc. is an answer that will work even for the Chieftain, which I have more than a few hours in. Its not fair for you to have to do all the work to solve a problem and Piper & Lycoming to do nothing.
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The drop-in concept is flawed. The automotive manufacturers had to make the changes 50 years ago. It would have been crazy then to expect the petro industry to make all the changes while the auto manufacturers did nothing in the overall effort to eliminate lead in the fuel.
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It has been years since I have looked at the fuels sold in Sweeden.
However, there are lots of ways to claim a fuel is “100” octane.
If you use the RON number (ASTM D2699) , that is not hard to do. If you use the correct MON (ASTM D2700) then that has never been deployed any where except through the ongoing of G100UL Avgas.
None of the proposed unleaded fuels - - other than G100UL Avgas - - can operate safely on a TIO-540J2x.
The Chieftain engine (Lyc. TIO-540J2B or J2BD ) ALREADY HAS A VERY LOW COMPRESSION RATIO! ~ 7.3:1.
You cannot lower the CR any further - - nor can you retard the 20 dBTDC timing any further and then still be able to operate the engine at normal power settings. (With or without “smart” EIS and/or with intercoolers.)
Why not ?
See if you or others can identify the specific operational reason why that cannot (does not) work ?
No, the “drop-in” concept is OK. You just have to define it correctly.
From the 1980s through about 2005, ASTM - - INSISTED on defining a “Drop In” replacement as a fuel that met all of the test parameters listed in the Hallowed “TABLE I” properties in the existing ASTM D910-100LL specification - - with one and ONLY one exception. No lead.
That was done deliberately to postpone any change to any other fuel. People in ASTM even cautioned others in ASTM to “… do not object or propose anything that does not meet that requirement.”
The appropriate definition for a “drop-in” fuel for 100LL is a fuel:
Those were the “Design Criteria” that we developed in January of 2010, at the beginning of the G100UL Avgas program.
In 2016, Phillips Petroleum met with Tim and I in their Houston Headquarters - - and I showed them a short power point with that set of design requirements. The senior P66 fuels engineer agreed that those were the correct design criteria.
GAMI’s approach to the problem:
Ok so I really think the G100UL is the best solution in the near term.
So what is the next airport to get it? Cant wait to try it and get the lead out.
I give to the readers to interpret if an aircraft is vehicle.
Regarding the Swedish unleaded 100 aviation octane AVGAS developed year 2006 it meets the ASTM D910 table 1 (for 100 LL) at that time in all aspects except for slightly lower energy content. The Cessna documentation states a slightly lower energy content will not be a problem, fuel consumption will be about the same.
However under certain circumstances even unleaded 100 octane avitation rating (not RON) is not sufficient for engines having a type certificate to operate on 100 LL. Leaded and unleaded octane numbers sometimes do not correspond pending fuel formula. In such a case for example an intecooler may add extra margin. Also water-methanol injection used together with such an 100 aviation rating unleaded AVGAS will give the extra octane needed to be on the safe side when needed. The injection of water-methanol will thus not be needed to use all the time - just under certain conditions.
The aviation consumer will at the end chose the UL100 product they will use.
Yes, there is “something” about “altitude” that does require “high octane.”
The compressor discharge temperature of a Lycoming TIO-540J2DB at 20,000 feet on an FAA hot day is about 330 degrees F.
Shove that hot air into your very low (7.3:1) compression Navajo engine operating at 30" of MAP / 2400 RPM and operating on anything less than 100MON /130PN rated gasoline and it will begin to detonate. But only for a short while .
Lars,
What is the chemical composition of that Swedish unleaded 100 aviation octane AVGAS that was developed in 2006 ?
Is it currently being produced ?
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This must be the FAA’s response to Russ’ Op-Ed… Read this link and tell us here what the purpose of EAGLE and PAFI is.
https://www.faasafety.gov/spans/noticeView.aspx?nid=14142
The FAA has gotten into the Word-Salad business. They should have used AI to write this it would have had a little more substance.
https://flyeagle.org/eagles-four-pillars/
Has the experts checked-off a single one of the items in their “Four Pillars”?
I guess they do have the ESG requirement checked -off.
The Swedish unleaded aviation octane AVGAS developed year 2006 was with European made components. All the data were repeated and verified by US reputable AVGAS laboratory in 2013 and then with components made in America.
There are valid world-wide patents on the fuel inclusive the US, Canada etc. so there is no need for me to reveal any chemical composition.
As for Sweden today about 80 % in volume of all AVGAS consumed already is unleaded with Hjelmco AVGAS 91/96 UL ® (UL94 and competitors UL91) the communities seem to be satisfied with the work already producing reduced levels of lead in the air so 100LL does not seem to be a acute problem. Remember Sweden has uninterupted production and use nationwide of unleaded AVGAS now for 43 years! Also lead is the cheapest way to obtain high octane levels - and the market seems to prefer having the lowest price possible on 100 octane AVGAS and appreciate that the Hjelmco unleaded AVGAS during all these 43 years inclusive today has carried a price about 15 % lower than that for 100 LL.
Also with our unleaded AVGAS in Sweden traditional aircraft engines made by US companies tend to go about 3000 hours before their major overhaul.
As said before 2032 seems to be the target to replace 100 LL.
Unleaded is however not the issue today. That train has already left the station. Today the issue is to make bio-AVGAS meeting ASTM standards and at the possible lowest cost.
Work is actively ongoing on that subject in the ASTM right now and with participation of US companies.
I am glad we have the ASTM and other standardization organizations because it will secure the Aviation Consumer worldwide in the not so far future to have a 100 aviation octane bio AVGAS meeting an ASTM standard and made in competition among component producers and fuel producers/blenders. An ASTM standard or its European equivalent standard is the Defence Standard (DEF/STAN) issued by the Ministry of Defence in England.
I copy from the DEF/STAN AVGAS standard and the authority it has:
The Technical Authority is the Defence Strategic Fuels Authority, Larch 3B #2317, MOD Abbey
Wood, Bristol, BS34 8JH. This standard has been produced on behalf of the Ministry of Defence
(MoD) by the Aviation Fuels Committee (AFC) under the governance of the DSFA and Military
Aviation Authority (MAA) Fuels, Lubricants and Gases Airworthiness Advisory Group (FLAAG).
English is not my mother tongue - but I refer in defintions to US law 18 U.S.C. § 2311.
I assume you’re referring to these sections:
As used in this chapter:
“Aircraft” means any contrivance now known or hereafter invented, used, or designed for navigation of or for flight in the air;
[…]
“Motor vehicle” includes an automobile, automobile truck, automobile wagon, motorcycle, or any other self-propelled vehicle designed for running on land but not on rails;
[…]
“Vessel” means any watercraft or other contrivance used or designed for transportation or navigation on, under, or immediately above, water.
An important distinction: the simple term “vehicle” is never defined. What is defined is “motor vehicle” (emphasis mine).
In common U.S. usage, a “motor vehicle” is invariably ground borne transportation; “vehicle” alone has no such restriction - we have plenty of UAVs flying around.
In addition, the U.S.C. consistently uses the full term when referring to self-propelled, ground based vehicles in other sections of the code.
Lars,
Is there any data which documents the extended intervals (out to 3,000 hours) before major overhaul when using unleaded aviation gasoline in Sweden ?
George
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Thank you, Russ for your usual great reporting and analysis.
Why not file a suit against d’Acosta et al. for self dealing? Does anyone know their way around the legal system well enough to get the Justice department, the SEC, and/or the OMB to look into Eagle etc.?
In Sweden you operate an engine to the TBO if having it in commercial operations. However if you have an aero-club and alike they are not considered commercial and thus you may extend the TBO by 50 %. This is also valid for private operations.
I hear from our customers that many 100 % fully working engines have to be sent in for TBO at 3000 hours - because of the time limit. For statistics I assume engine manufacturers have reliable data. I assume the extention in hours between oil change by engine manufacturers is a result from such statistics. However such an extension for oil changes might not be done everywhere as it is regulated in the service manual from the air-frame producer. Oil changes thus typically take place in Sweden every 50 hours with a modern oil-filtration system.