One of the questions I wanted answered at this year’s AirVenture in Oshkosh was “what is the latest on unleaded avgas?” To find out, I did numerous interviews and attended several seminars.
The big news was the immediate introduction of a 94 motor octane unleaded avgas by Swift Fuels. The fuel will be marketed with Petersen Aviation since the product meets the requirement of all of Petersen’s STCs.
The fuel also meets ASTM D7592, ASTM D7547 and ASTM D4814. D4814 is the general spec for auto gas that is listed in the Petersen and Experimental Aircraft Association‘s STCs for auto gas. The D7592 spec is for a fuel that is basically 100LL without the lead. D7547 is basically the same and is being used by European refineries for markets in other countries.
Officials from Swift Fuels were listing all of the attributes of the new product and the work needed to develop it. I then asked if it was just 100LL without the lead and they finally admitted that that was basically what it was.
Now, I applaud their efforts and feel that they will sell some product. My first question, though, is why did they not just say that it also meets ASTM D910 for an 80/87 fuel since that spec lists only a maximum of 0.5 G/Gal TEL with no minimum? That would mean that they could sell it to all pilots with 80/87 engines with no STC.
The other concern is cost. I know that everyone thinks that an unleaded fuel will be significantly cheaper because it can be shipped by pipeline vs. 100LL which cannot. But the fuel is still going to be a boutique fuel and will need to be handled in dedicated facilities to keep it in spec. This means that the cost will be very close to that of 100LL, which may reduce the volume of sales.
Along with Swift, I also talked to officials with Shell and General Aviation Modifications Inc. (GAMI) about their respective 100 Motor Octane unleaded fuel candidates. I will address the GAMI interview in a later column.
Shell and Swift are both working with a cooperative group to develop a drop-in 100 Motor Octane unleaded fuel. They are working with the FAA, EPA, ASTM, and a bunch of other alphabet groups. The group has identified three candidate fuels for further testing (two from Swift and one from Shell). The two Swift candidates are “pure hydrocarbon” fuels and the Shell candidate contains an anti-knock additive system.
The program will look at a multitude of performance characteristics and then do flight evaluations. The end goal is to have the fuel or fuels approved for use in all Continental and Lycoming engines, and probably also Rotax and other Light-Sport Aircraft (LSA) engines.
Does anyone see a problem here? What about the Pratt & Whitney engines, as well as the Wrights and other orphan engines out there in the fleet? Their answer to that question was that “they” will get to them later. But who is the “they” that will do the work, who will pay for it, and — most important — who will stand behind the answer and assume liability for any problems?
The other problem is when they approve the unleaded fuels, who will sell it? FBO’s will have the option of selling mogas, 94UL, 100UL or 100LL, all at about the same cost. With only one fuel system I would probably bet on them staying with 100LL because it is the only one to work in all aircraft.
One of the most surprising observations at Oshkosh came from several sources that I consider people who understand the “show.” They all felt that there was a change in the attitude of the aviation community regarding the “unleaded fuel” problem, which used to be a “gloom and doom attitude.”
It was unanimous for this group: They were all optimistic that, in the long run, 100LL is not really going to go away for quite some time.
It is definitely worthwhile to stick around just to see what happens next.
“… why did they not just say that it also meets ASTM D910 for an 80/87 fuel since that spec lists only a maximum of 0.5 G/Gal TEL with no minimum?”
I believe that is because some years ago, after 80/87 was phased out, ASTM put in a requirement in D910 that aviation gasoline HAS to have some amount of TEL in it. That is why Hjelmco gasoline is “D910” compliant but is also sold as “unleaded.” According to the Hjelmco website, “The amount of lead is however so trifling it fits into the definition of being unleaded i.e. < 0,002 g/liter." It is allowable to advertise this gasoline as "unleaded" by European law even though it has TEL in it.
It is also the reason that ASTM D7547 came about. When DOD approached ASTM some years back to get a spec for their Predator drones that they could give to third world refiners because auto fuel was so inconsistent that it was causing problems in the Predators, they thought it could be enacted quicky by specifying D910 WITHOUT TEL. But ASTM didn't want to take the TEL out of D910 so they created a new spec, and as I remember it, they did it in record time. At the same time ASTM D7592, essentially D910 without TEL, had been in process for years and it wasn't finished until after D7547.
So I don't think Swift could say its fuel meets D910 for 89/87 without TEL because today 80/87 would have to be manufactured with some TEL in it to be D910 compliant. Kind of a Catch 22.
Soooo why not get ASTM to change D910 back to what it’s supposed to be? It wasn’t reasonable for ASTM to change the spec to require lead in the first place.
Or better yet, if ASTM is misbehaving, why not advertise that Swift meets the *1975* version of the D910 standard, or whatever version last existed without requiring lead?
I believe all standards are date-stamped, right? Nothing wrong with announcing that you meet an old version of the standard.
Planes which required compliance with the version of the standard in use at time of manufacture… still require compliance with the version of the standard *in use at time of manufacture*, not some newer version, so legally you should be safe enough.
The lead is a huge problem for general aviation. But I think even more important to pilots is the cost of avgas. That is why I am excited about Swift Fuels unleaded avgas. I have seen it a dollar cheaper than 100LL.
I to am curious why it would not also met ASTM D910
Because it has no TEL in it. All aviation fuel meeting D910 is required to TEL in it.
It is such a small amount of lead I wonder if there is a process that could be developed that would allow lead to be added after it is sold to the consumer.
Gentlemen, the bottom line just like any thing else today is, “Greed”. The manufacture of fuels can come up with any type of fuel that is needed and they always have, the most important aspect of all this is how can they present it to the aviation industry and make a killing on the profit. That my friends is the bottom line. I’ve been around a long time and it always is profit. I remember when Standard gas stations sold gasoline on there three pumps, red, blue, and white pumps. It was regular 91 octane, blue pump was 94 octane and what they called, ” custom supreme 100 octane,white pump, all these were leaded fuels. On Saturdays we would all fill up our cars and go racing at the drag strips in So. Cal. Custom supreme was $.39 a gallon. The point i’m making is it can all be done in a civil way and keeping the cost down with no problem. All of a sudden our mfg. co’s. can’t make any fuel without a whole lot of completed crap. This is worse than the Government, what do you think ????? thank you
Get the lead out of aviation gasoline by converting to diesel engines in the future. I know, that’s easier said than done but still gasoline is a carry over from the beginning when diesel technology wasn’t what it is today.
A second avgas tank could be installed at low cost, a turn-key system can be had for about $ 30,000 retail not much to a city/county budget. The “problem” of needing another tank is simply an excuse that lets the airport officials spend time and money “studying” the problem. Airports are run by politicians who will keep having meetings until they find out why nothing is being done. Two tanks were not a problem when refiners made grade 80 it is not a real problem now.
In actuality, the need for two fuel systems was a large problem for the general aviation community FBO’s. In the good old days, GA airports had two systems, one for 100 high lead and the other for 80/87. Then when jet fuel started to become popular in GA, FBO’s started to switch one system over to Jet A and drop 80/87. Therefore, the oil industry came up with 100LL so that the FBO’s did not need another fuel system.
Mr. Visser,
I do not disagree that cost was or could be a factor to small private FBOs.
I have been working in General Aviation since 1982 and remember well the fuel systems that I dealt with. The city and county owned airports that I have worked at and currently use have all had airport,not FBO, owned systems, those are what I was referring to as to cost of a second tank today. When the grade 80 became unobtainable those tanks in Lansing, Charlotte, and Pontiac MI,as well as other Michigan airports, sat empty until removed as scrap they were not converted to Jet fuel.
I do very much appreciate your question of, ” why did they not just say that it also meets ASTM D910 for an 80/87 fuel since that spec lists only a maximum of 0.5 G/Gal TEL with no minimum? That would mean that they could sell it to all pilots with 80/87 engines with no STC.” Many do not realize that much of the grade 80,(80/87) was no lead lead was added only if the base fuel did not meet the octane requirement, not to “lubricate” valves. Remember the problems of the switch to 100LL? the extended spark-plugs,sticking valves, the new operating instructions from the engine manufactures? Your question was especially good in that most pilot/owners are completely unaware that using 100LL in their airplane is not approved, it is “acceptable” to use the “next higher grade” until the proper fuel can be obtained, and yet they did not need to purchase a STC to use it. The type cert, will state in most cases “aviation gasoline” not an ATSM spec.many currently operating aircraft were never tested on an ASTM spec. fuel let alone 100LL.
Thank you again for your informative columns, keep asking questions, and answering them.
It sounds from what you’re saying that most owners with 80/87 aircraft *are* authorized to use Swift 94 *right now*, with no STC required, because it is the next higher grade.
Ben, Thanks for this update and keep them coming. Sometimes I think most pilots and owners have decided this will just go away if we let the FAA and EPA etc talk it to death. Of course as the pilots overall age continues to rise the majority of pilots may be right…. we may die of old age before there is a solution.
I hope not, I think this can and will be solved.
The GA industry and pilot/owner community has been dragging their feet on the leaded fuel issue for decades. It’s time to move beyond 1970 and get the lead out.
There’s a general attitude in GA that any innovation in airframes or especially powerplants must be miraculously perfect in every way, or the owner/pilot community won’t accept it. There’s always some obscure excuse for rejecting something new. The result is that we’re stuck with antiquated technology that makes us look out of date to the rest of the world.
Automobile gas stations all over the country, even in remote areas, sell several grades of gasoline, with no problem. Surely the GA industry could come up with a way to sell fuel other than 100LL if they put their mind to it.
They do that by having two tanks-regular and premium. Any grades offered other than 87 and 93 are simply mixtures of the two in the ratio needed to achieve the correct octane. And none of them have lead. There could be no mixing of these fuels, and unlike an auto gas pump, aviation pumps need 30-40 feet of hose for each kind of fuel…the list goes on. I agree with your statement on miraculously perfect innovation or nothing, and I agree getting lead out of fuel would be wonderful. Look what it has done for automobiles. Engines now run 2-300,000 miles with no problem, fuel injection with computer control is wonderful, etc. Why we can’t have that same progress with airplanes is mystifying, unless it is these two obstacles: 1. Antediluvian regulations and certification procedures on the part of the FAA. 2. There simply isn’t enough demand for manufacturers to do it. Aviation is a tiny market compared to automobiles.
We must also remember LIABILITY. In the real world, if things are not perfect in the aviation world, one gets sued. And this kills a lot of new ideas and technology.
For dumping lead into the air, you’re very likely to get sued — and lose. The evidence is coming in fast and heavy that it’s causing actual harm. People can and will sue airports and pilots for causing brain damage to their children. “The EPA said it was OK” is no excuse in court.
If there’s any concern about liability, you should be getting rid of the lead ASAP!
Actually, compliance with Federal law is still a valid defense in the courts of the United States of America (as established by our Constitution). Also, the burden of proof always rests on the plaintiff(s) (in this case the hypothetical people suing airports and pilots for causing brain damage to their children) who would have a very challenging case linking any such damages to individual pilots or aircraft. Perhaps you meant that people can sue the EPA for their laws that are perceived to facilitate their children suffering lead poisoning?
Additionally, the FAA and EPA are collectively working towards “getting rid of the lead ASAP” but are faced with numerous technical challenges. One major challenge is identifying a suitable alternative to lead which offers equal (or possibly better) anti-knock properties than those available in 100LL avgas. Since aviation engines operate at high compression ratios, high octane fuel is required to prevent engine knock (pre-detonation) which can lead to piston crown hot spots and piston failure. Piston failure is definitely not a desirable situation for any pilot considering that this immediately ends the useful life of the engine and brings the aircraft to the ground wherever it may be. Since lives are at stake (pilots and people on the ground) the FAA and EPA will take as long as is necessary to identify an unleaded fuel that provides at least the same anti-knock performance as 100LL 100% of the time.
Ben, thank you for trying to cut through some of the smoke and mirrors of the “developments” on an unleaded fuel. I think your 11th paragraph says it all. Airports, especially small ones, do not have the money to install delivery systems for all of these different gasolines. And as you say, who will stand behind and guarantee all of them? Especially when it looks as though there will be no significant price savings over 100LL. I would rather see affordable diesel/Jet-A conversion alternatives for small piston engined aircraft. $60-$100k conversions are not going to fly, if you’ll pardon the pun. On the other hand, what happens when TEL is no longer available? Thanks, and keep asking questions!