When I learned this a while back it blew my mind. Why are people allowed to dump lead on habited areas for a hobby? I understand if it were allowed for some commercial use, but to allow it for some random Joe who just wants to dick about in the sky. It seems wrong. I think there would be an outrage if it was something well known. I was also curious how much damage it is causing and found this article which says 16 million Americans are potentially affected, those living close to airports. [1]
In Europe all new training aircraft are using diesel(-like) engines now which run on jet fuel or even straight diesel. It's not exactly hard to make the switch.
I suspect way over half and perhaps 80+% of the 100LL is burned by commercial operations (commuter airplanes (Cape Air type), aerial application, power and pipeline patrol, fish spotting, cherry drying, banner tows, etc.)
Private pilots just don’t fly that much compared to the small commercial operators. (And the few that do are likely to upgrade to turbine equipment, burning Jet-A.)
> Private pilots just don’t fly that much compared to the small commercial operators. (And the few that do are likely to upgrade to turbine equipment, burning Jet-A.)
Why aren't those small commercial operators that fly a lot then upgrading to Jet-A burning equipment?
Cost. Turbine engines are expensive to buy. (Think $500K-$1500K each for small ones vs $35K-75K for pistons.)
Cape Air passengers aren’t willing to pay enough to let Cape Air operate B200s or Metros.
The mostly business owners flying themselves privately in support of their business have more money to spend on tools to run their business than Cape Air pax or banner tow advertisers. They went turbine because turbine engines have incredible dispatch reliability.
Believe me, if turboprops cost anywhere near the same, the piston airplane market would evaporate overnight.
Cool. It’s the turbine that provides the reliability and that happens to burn Jet-A rather than the Jet-A that provides the reliability and happens to be a turbine so the subject change was extraordinarily unlikely to be detected.
Spinny-spinny works a lot more reliably than the suck-squeeze-bang-blow monkey-motion needed by reciprocating engines.
My pilot friend once told me that turbines aren't really appropriate for hobbyist use - they are limited in start/stop cycles due to the heating/cooling stresses, and consume tons of fuel at idle. They are also really, really loud.
Simply because light aircraft represent a really tiny proportion of global emissions.
And for "random Joe who wants to dick about in the sky", chances are that he is the one who is flying your airliner. Flying light aircraft is actually a really important part of what will eventually make good commercial pilots. There is a lot to say about that but the idea is that letting people dick about in the sky is not without merit.
Of course, it doesn't mean things shouldn't change, and I sincerely think 100LL has been a problem for way too long.
Problem is: change in aviation is really slow. Regulators are very conservative, every modification requires tons of paperwork, inspections and approval. Also, light aircraft tend to last long, they are actually simple, robust, and easy to repair machines, and many 50+ year old planes are still flying.
As for "all new training aircraft in Europe". I fly in France and I never saw a diesel plane. I know they exist, I just never saw one. On the other hand, I saw many Robin DR-400s with good old Lycoming engines running 100LL. In fact, in small airfields, when there is fuel, it is usually only 100LL. Maybe you can find diesel planes in larger airports where they stock jet fuel and have high turnover flight schools. I don't fly there.
And BTW, I a fly a Tecnam P92 with a Rotax 912 engine. It runs on unleaded gas, same as my car. But it is in the ultralight class, a much less restrictive category regarding regulations, and as a result, usually a bit more "modern" (if you can call a carburetor-based engine that...).
>Simply because light aircraft represent a really tiny proportion of global emissions.
That would be a valid point if the context was CO2 emissions. It doesn't seem to me like such a valid point when talking about lead, where local concentrations near populations matter.
>And for "random Joe who wants to dick about in the sky", chances are that he is the one who is flying your airliner.
"X is an necessary person" is not a logical argument for "what X is doing is necessary". Seems like a misapplication of a sort of transitive property.
> "X is an necessary person" is not a logical argument for "what X is doing is necessary". Seems like a misapplication of a sort of transitive property.
As I said, there is a lot to say about that. The idea is that it creates a culture around aviation that ultimately produces good commercial pilots. Pilots from countries where recreational aviation is not as developed are usually not as good, I saw an article about that but I don't remember it. I think it was about a crash that could have be prevented had the pilot reacted correctly.
Ok, a common path for a commercial pilot in the US is to start to learn how to fly in a small aircraft with an instructor. Then fly by himself. But flying is expensive, so many future pilots become instructors themselves, so that they can do a lot of hours and pay for qualifications that become more expensive as planes become bigger and more complex.
When they finally get to fly an airliner, they have a lot of experience, and more importantly a lot of it as a pilot in command (flying solo is being a pilot in command). Not only that but being a flight instructor is excellent training, you have to let your student make mistakes while guaranteeing his safety. In the end, you have pilots with great decision making abilities, which is one of the main reason for them to be there the first place.
This is only possible in countries with a strong aviation culture. Without airfields, without people who just want to fly for fun, you can't be a flight instructors if you have no one to instruct.
Some countries do not have that culture, and future pilots are instead trained in flight schools that train them to be operational as quickly as possible. Problem is: they spent almost all of their flight hours as students, so maybe they know how to fly, but they are not used to take responsibility for the plane.
So letting people dick around in the sky may not be necessary, but certainly contributes to making better pilots.
I have mixed feelings about aviation culture. I grew up near an airport with planes frequently overhead, and used to read Flying in high school. I attended Embry Riddle as an undergraduate, but didn't take flying lessons. Some people were decent, others yelled "f-gg-t" at my long hair. At this point, I'm never going to be a pilot due to medical requirements.
The pilot in my extended family can afford to own and maintain a small aircraft because he sold a tech company that he founded, so he has no intention or need to work for an airline.
People talk about "environmental justice", it's a thing, right. People who live in the vicinity of airports and presumably are breathing the lead, are often, I think, not the same socioeconomic class that takes a lot of commercial flights, let alone flies private planes.
So what I'm saying is, I don't hate private pilots, but if I was dictator, I would ban leaded gas, with the understanding that there would be consequences and screaming, and be indifferent to it. I don't think it's a hard choice as to what would be better for society even if there are tradeoffs.
Why should hobbies be prioritized below commercial interests?
There's good arguments for exactly the opposite: Hobby use is often much less intensive than commercial use, and at the same time, much more price sensitive.
for one thing, there just aren't that many of them. there are under 200k hobbyist pilots in the US, and they mostly fly small single-engine planes. it's a problem, but it's pretty far down the list of emissions concerns. see also: two stroke engines in lawnmowers, boats, etc.
Lead is an issue not because of the general fact that it is dirty pollution (like two-stroke engines), but because of the precise neurological effects of lead in human bodies specifically.
There is a difference between sprinkling sulphur dioxide over an area and, say, plutonium.
Continued use of leaded fuel over time means it can build up in the environment. Living near an airport now I'm reluctant to eat anything from gardens nearby.
> I understand if it were allowed for some commercial use […]
You mean like all the flight schools that use 1970-era Cessnas as part of the training fleet? Or old King Airs to build hours for multi-engine qualifications?
>In Europe all new training aircraft are using diesel(-like) engines now which run on jet fuel or even straight diesel. It's not exactly hard to make the switch.
Would make sense if there was taxpayer-funded healthcare, because then you could use the money those companies pay as taxes to fund the treatment of those they poisoned...
I'm all for healthcare, but, on topic, it'd make even more sense to find replacements one-at-a-time for all of the products we use daily that are made up in part by crude oil.
Most plastics, many foods, many skin products, etc. all come from some by-product of oil. Because of that dependence, big oil is not only a huge industry, it's most industries, most company, most products, and touches most consumers.
Also:
"There are 1.65 trillion barrels of proven oil reserves in the world as of 2016. The world has proven reserves equivalent to 46.6 times its annual consumption levels. This means it has about 47 years of oil left."[1]
Wars have been fought over it when we still had a lot left, and we've got until maybe 2068.
Clicking on this article with no context makes it very difficult to understand if you don't already know what 100UL and avgas means. Took me 2 paragraphs of confusion to figure out "avgas" is aviation fuel and 100UL means 100 Octane Unleaded.
At the top of the page they say "WORLD'S PREMIER INDEPENDENT AVIATION NEWS RESOURCE".
The author assumes that if you're reading AV Web, then you're already somewhat familiar with the aviation scene and some of its jargon. We're not talking about an article published in the New York Times or Forbes here.
I second this, I had to really read the whole article before I totally got the big picture. A little context explaining ought to be done near the start.
The problem isn't so much the fuel, it's the ancient piston aircraft (or at least, ancient engine designs) that are still kicking around.
There are modern piston aircraft engines that not only run fine on unleaded fuel [1], but are even certified to run on standard automotive fuel ("Mogas"). There are videos on YouTube of pilots landing on remote highways and pulling up to regular gas station pumps to refuel their aircraft!
> The problem isn't so much the fuel, it's the ancient piston aircraft (or at least, ancient engine designs) that are still kicking around.
Yes, that's my understanding too. Aviation piston engines are stuck in 1950, largely because more stringent regulations have made it more expensive to develop new engines vs. keeping producing largely existing engine designs grandfathered in, and also because the market is pretty small.
> There are modern piston aircraft engines that not only run fine on unleaded fuel [1], but are even certified to run on standard automotive fuel ("Mogas"). There are videos on YouTube of pilots landing on remote highways and pulling up to regular gas station pumps to refuel their aircraft!
AFAIK the usefulness of this has been reduced, due to a lot of automotive gas containing ethanol. The engine itself might work fine with an ethanol blend, but the fuel system (bladders, lines, etc.) might not. There is apparently also a fear of vapor lock or other trouble if the ethanol and the rest of the fuel separate in the tank.
Right. Contaminants like ethanol are no bueno. Ethanol absorbs water from the air, and an ethanol-water mixture corrodes fuel lines, gaskets, and other parts. And thanks to the EPA and the corn lobby, it’s getting harder and harder to find uncontaminated gasoline.
I’m all for the transition to 100UL. I don’t want to breathe lead either. But they need to either come up with a replacement that won’t destroy airplane engines, or they must fund the replacement of everyone’s engine with ones that will work with (and can be certified for) the new fuel.
> There are modern piston aircraft engines that not only run fine on unleaded fuel [1], but are even certified to run on standard automotive fuel ("Mogas").
Note that mogas is not necessarily the same as what one gets at a car gas station, called pump gas by some:
> Automotive fuel from the pump is NOT the same everywhere you go. There are summer blends, winter blends, geographical blends within the seasonal changes, varying levels and types of oxygenates (not just ethanol) and when tanks are switched over a mixture of "in between". The pump labeling is accurate for octane, and in some parts of the world, the maximum percentage of ethanol. It doesn't tell you everything you need to know to make "pump gas" fit-for-purpose for aviation and it's not just about octane and ethanol. We need to control a wider range of fuel properties for aviation. Your equipment, your life and the lives of your passengers depend on it. Let's walk through exactly what Lycoming did in authorizing automotive gasoline - "mogas" - for our engines. It's also suggested that you read Section B of the latest revision to Lycoming Service Instruction 1070 - and read it carefully.
My airplane has a 1950s era engine (Continental O-300), which is able to run on automotive fuel (“mogas”). However, mogas is not much available at the airports. If there was a way to obtain it, I would use it. But it’s almost never an option.
One of the local flight clubs where I live has a trailer full of gas canisters. Once a week, someone drives with the trailer to one of the few gas stations left with ethanol-free fuel and fills up the canisters. It’s a lot of work but it saves the club a lot of money since mogas is much cheaper than avgas.
Very few piston airplanes above the entry-level and trainer fleet are normally aspirated. The piston airplanes that fly a lot (mostly in commercial service) are overwhelmingly turbocharged.
Those are the ones that need the higher octane fuel (and the ones that burn the most of it). I could have bought paperwork (the Petersen STC) to allow my Cessna 182 to burn alcohol-free unleaded car gas. That is not available for the replacement engine I installed in that airplane nor for my current airplane (nor any turbo airplanes to my knowledge).
Which is tiny; it has 115 horsepower for 5 minutes and 100 continuous. That’s still trainer and entry level or 2-seat Cessna 152 sized engine and about 1/3 the power of a modern single-engine Bonanza.
For what it's worth, some kit planes are now using the Rotax 915iS (Newer injected variant of the 914) for 4-seaters [1]. This engine puts out 135 continous up to 15,000 ft. For comparison, a given Lycoming 161HP non-turbo engine (requiring 100LL) shouldn't run above 75% continous (120HP), and can't put out more than this above 9,000 ft [2].
There certainly seems to be some innovation here, in this case driven by Diamond in Austria. It may have "helped" that Avgas prices over here in Europe are really quite high.
In my non-expert uninformed opinion, if the political will would be there UL94 would have replaced 100LL a long time ago. UL94 is basically 100LL but without the lead, so we certainly know how to produce it worldwide at decent cost.
- Most planes could switch without any change
- Yes, in some cases, changes would be needed, like
- detuning.
- installing an electronic ignition timing system.
- Installing a new engine, either a newer gasoline engine, a diesel engine, or a turbine engine.
- Scrapping the plane and buying a new one.
Sure, this would incur cost for some, but c'est la vie. Many such decisions have been made in societies all over the world, often for good reasons.
This could still be the solution if the EPA puts their foot down and the PAFI thing mentioned doesn't produce a workable 100UL recipe.
flying is already an inherently expensive, niche hobby. it's cool that it exists at all, but I don't think it would be some enormous injustice to price a few more people out.
a reasonable solution might be to grandfather in all existing engines that are only certified for leaded fuel. as long as the use is non-commercial and/or doesn't exceed some number of hours per year, you can keep using that engine until it dies. once it does (or you want a new plane) you have to use unleaded fuel.
> flying is already an inherently expensive, niche hobby. it's cool that it exists at all, but I don't think it would be some enormous injustice to price a few more people out.
Yes.
> a reasonable solution might be to grandfather in all existing engines that are only certified for leaded fuel. as long as the use is non-commercial and/or doesn't exceed some number of hours per year, you can keep using that engine until it dies. once it does (or you want a new plane) you have to use unleaded fuel.
I'm not sure that's workable. Apparently a large fraction of the piston engine aircraft fleet is decades old, and the replacement rate is very low. So you'd have a very long transition period. Further, GA is such a small niche market anyway that smaller airports are very reluctant to provide more than one gasoline variant.
I think it'd be more realistic to set some date after which sale of leaded AVGAS is prohibited. That's what was done when leaded automotive gas was banned. Those with cars unable to use unleaded gas just had to suck up whatever expenses were needed, or stop driving.
> it's cool that it exists at all, but I don't think it would be some enormous injustice to price a few more people out.
Except for all the flight schools that are part of the pipeline for training pilots. A lot of smaller shops use airplanes from many decades ago, and mandating that they swap in a new engine (at a cost of tens of thousands of dollars) for each plane (in their fleet), could be ruinous.
ultimately some businesses are going to need to feel the consequences of environmentally unsustainable practices. as another example, there might not be a future for cheap cruise ships that burn bunker fuel.
if it would be truly ruinous to the pilot training pipeline, you could grandfather in the smaller flight schools. my main thought here is that we should not continue to manufacture engines that burn leaded fuel. there's plenty of room to compromise over who gets to continue using engines that already exist.
> my main thought here is that we should not continue to manufacture engines that burn leaded fuel.
I don't disagree with you, but there are many thousands of perfectly good planes from previous decades that are in good shape (they have to be inspected annually) that will be a long legacy.
Right now I can find 63 pre-1960 single-piston aircraft for sale, with the cheapest being US$ 42K from 1945 as I type this:
There are already electric training aircraft certified in Europe [1]. In the coming years and decades, these will very likely greatly reduce costs (fuel, maintenance) for flight schools while eliminating lead, and other emissions.
the actual quote from the scientific american article:
> The EPA estimates that 16 million Americans live close to one of 22,000 airports where leaded avgas is routinely used—and three million children go to schools near these airports.
16 million people living near airports where leaded avgas is used is not the same thing as 16 million confirmed cases of lead poisoning. there's no need to exaggerate.
And assuming a linear no-threshold risk model we want to keep it as low as possible. People spraying leaded exhaust over cities for fun is not consistent with that.
I see no argument as to why going to the moon was easier. That sort of title diminishes the sacrifices and accomplishments involved with going to the moon.
It's not a theoretical question, we have the events and the outcomes, complete: The time it took from announcement to actually landing on the moon was shorter than the time it took from recognizing the lead problem to banning it from all fuel including aviation fuel. The second one already is longer. So whatever your model of reality, the complete model is reality itself and it proves that point. What else would be better for arguing than the actual real-world outcomes?
If you want to say things like "but there were less people working on the problem" you are removing things from the real world to build a more limited model to fit your argument. Overall getting enough people to work on the problem is part of it. Including everything, which includes getting attention and resources devoted to a problem in the first place, the moon landing indeed was easier. I think it's not much of an argument that exactly that, getting a vast effort rolling and people and resources devoted to a problem, really is one of the hardest problems. It was pretty easily achieved for the moon landing.
If you want to separate the policy problem of getting the resources from the technology problem you are only looking at a part, to get the desired outcome both are needed. Sure, the technology part was harder for the moon landing - which makes it even worse that the other part, the policy stuff, is so hard to accomplish.
The elapsed calendar time from the birth of the first human to when an electronic drink blender was first invented was much longer, but I wouldn't say that was more effort and sacrifice than getting to the moon.
Do you know how many lives were lost in Germany, prisoners marched in the cold by force, a huge number of them dying along the way, to dig underground missile production factories with their bare hands, being shot if they stopped? Or that those men leading those atrocious slave factories were then effectively saved from certain death from war crime tribunal, just to help with the early U.S. rocket program that went into the moon effort?[1][2]
That's not even including the sacrifices leading up to it by the U.S. and the U.S.S.R., which I'd include in the overall effort[3][4].
Certainly, fewer people died in those camps than have died of lead poisoning from avgas since. (The article says 16 million people are currently impacted by lead from airplane exhaust.)
>>The U.K.-based Innospec is believed to be the only remaining producer of TEL
Well, as a semi-interesting fact, UK is one of the very few countries where (extremely limited) sale of actual leaded petrol is still allowed at a handful of garages around the country. Pretty much exclusively used by owners of classic cars which haven't been modified to run on unleaded fuel. The list of garages that still sell it is here:
One can make any organic material from non-fossil sources with enough money. For example, one can make xylenes from sugar by demonstrated pathways (hydrodeoxygenation followed by reforming). p-xylene has been made this way as a renewable feedstock for making PET plastic. That chemical also has octane rating of 146 (RON) or 127 (MON).
They want a high octane unleaded fuel, that also otherwise largely matches the existing fuel (viscosity, density, vapor pressure profile etc.).
I don't specifically know what's wrong with xylene, but IIRC aromatics in general produce a lot of soot (PAH and other nasty carcinogens), which is why they've been steadily reducing the maximum allowable content in automotive gas.
Depends. If there's so much soot it reduces time between engine overhauls, that might not be good.
Then again, TEL causes shorter overhauls as well, so...
Anyway, like I said, there's a boatload of other properties the fuel has to satisfy as well. If it were as simple as just switching to p-xylene, presumably they would have already gone down that route.
It's time for airplanes that use leaded gasoline to go the way of xray machines for shoe fitting.
Toxic products, such as leaded gasoline, asbestos, tobacco, some pesticides, would had been outlawed much sooner if US had universal healthcare where poisoning of others costs us all - instead of being an externality.
Also worth noting that while the lean octane rating of avgas is 100 (as compared to auto fuel’s lean rating of around 85), the rich octane rating of avgas is around 130, providing increased margin against detonation on high-power takeoffs.
It’s a mistake to think “I can buy gas labeled as 93 octane at my local Shell station; surely they can find a way to find just 7 more points or detune the engine slightly.”
Sustainable aviation fuels are 50 years behind motor fuels because of the fear that changing fuels could cause your engine to fail.
For ground transportation we have methanol, ethanol, butanol and other ol's not to mention biodiesel, dimethyl ether, etc. Electric is a good option too.
For aviation fuel people are so scared of change that they are still trying to synthesize chain hydrocarbons from H and CO. (It's the one case where iron works as a catalyst but so poorly that they wish they could use Platinum instead.)
Desperate people such as Nazis and South Africans found that's not worth doing even if you have cheap coal. Now people want to capture CO2 from the air to do it. Yeah right.
There’s some element of fear as embodied in the aviation regulations.
There’s not as much fear in the owner/pilot population, in large part because of those regulations. If any of the 100UL candidates pass certification, it’s a fair bet that they’ll be safe and I’ll have no concern with flying on them.
The real issue is that while you can suffer a 10% power or energy-density reduction (such as from alcohol displacing gasoline in the fuel) in an automotive application without any appreciable loss of safety and minimal loss of functionality, the same is not true for aircraft. Piston aircraft takeoffs are always* done at maximum available power and a 10% loss of power is cause for an abort.
So it’s unlikely that a fuel with materially worse performance would be certified.
* - There were some extremely old multi-engine transports which had tables for reduced power takeoffs and some pilots mistakenly do them today, but the overwhelming practice is 100% of available.
Maximum power takeoff seems reasonable, and unexpected 10% power loss would be a very good reason to abort, but I don't see why you couldn't trade (stable and safe) 10% power for 10% runway and clearance, maybe some weight, altitude ..
You would need to reassess and update your tables, so regulations and certification are a big issue, but I don't understand why would it be technically unrealisable. Half a century after we know it's harmful seems a long time to stop spewing lead all over the place.
Legally, you would have to do certification tests on every airplane type again.
A 10% loss of power would require much more than 10% increase in runway for a given weight.
Further, a 10% loss of energy density would require heavier takeoff weights for any given trip, meaning the penalty is further increased. I’m already weight-limited (either by certification limits or runway performance) on some flights. I carry about equal mass of fuel and people on trips with the whole family aboard.
I’m not crying about it and I hope to see a viable 100UL emerge, but a 10% loss on two variables in the fuel would result in a lot more than “just use an extra 300 feet of takeoff roll and she’ll be a’ight”.
Takeoff is done at max power as best practice, not because it's physically strictly required power for lift-off. Yes you'd need to reduce weight tables and friends, but a certified detuning is totally possible, even if an in-the-field loss of power is cause for grounding.
A certified detuning is indeed theoretically possible, at the expense of having to re-flight test the airplane to determine and prove the new performance tables as part of the STC for that fuel, which any new fuel vendor will likely find to be a prohibitive barrier to sell the fuel to the public.
The "all models STC" approach with a "no degradation in performance" judgment is much more desirable for the fuel vendor seeking to sell the fuel, for the FBO who only wants to sell one version of avgas and one mix of Jet fuel, and for the owners of heavy piston-powered airplanes and therefore more likely to succeed (IMO).
It may be perfectly fine if you have cheap solar. It's a completely different problem from starting with coal.
Anyway, there are planes that use ethanol internal combustion, and methane reaction engines. There have been for ages. Those fuels aren't widely used because they are hard to handle and lose performance on the normal passenger transportation conditions. The reason they are more common on cars is because performance matter much less on road transportation, not because of any lack of testing.
I think it is not a different problem. The FT process depends on many different paths, some of which build up larger molecules and some of which break them down.
If you insist on making liquid hydrocarbons you need to be balanced on a knife edge -- HCs like to polymerize towards polyethylene (violently, blow up the container so) or break down to methane when heated. Thus you need a big factory to make a small amount of product and you might need to shut it down when the reaction vessel gunks up with petroleum jelly.
With solar and carbon capture now you need to run an aniline stripper and a hydrogen factory but people dont care because of unicorns, rainbows, and all that.
Isn't one of the big uses of FT the production of synthetic motor oil?
There is another process for synthetic gasoline that goes through methanol, which is reformed to hydrocarbons (with lots of aromatics) on zeolite catalysts.
AFAICS GA is a much smaller thing in Europe, and European regulators have largely taken a lets wait and see attitude, and will presumably follow whatever the US counterparts will end up doing.
100LL is very expensive in Europe, and thus there has been more interest in diesel piston engines.
In Europe all new training aircraft are using diesel(-like) engines now which run on jet fuel or even straight diesel. It's not exactly hard to make the switch.
[1] https://www.scientificamerican.com/article/lead-in-aviation-...