We're working on it, slowly but surely. This has been a known problem for a long time, at least since 2009 if not earlier. GAMI's G100UL was approved as a 100LL replacement in 2022, but there is still some controversy.
Avweb has done a good series of videos on this. There were some real engineering concerns and some typical aviation conservative decision making. But really, it's a tragedy of the FAA fumbling the ball for decades at this point.
People who absolve engineers of all responsibility annoy me to no end. They're omnipresent on this forum and justify working for Facebook with things like "not my decision" or "someone else would do it" or "it's not that bad you just don't understand" or "I'm just following orders"
Based on the OP, it wasn't at all accidental. They knew it was dangerous and chose it because they could make more money than with safer alternatives such as ethanol.
He's not some incidental commentator. He's an engineer and a principle force behind this technology. He is responsible for the outcomes - 'I didn't know' is reckless negligence. And if there were clear acute problems, chronic problems weren't hard to guess at for anyone, much less an engineer, with all those resources, working on it for years.
Robert Kehoe, working for GM, was the chief advocate for leaded gasoline, and really the only person/lab doing research on lead until Clair Patterson stumbled into it while measuring the age of the earth. [0,1]
A modern equivalent might be if Facebook was the only organization researching social media's impact on society, while being able to set the paradigm/assumptions about said safety for half a century.
So even when Patterson's research was published in 1965, it took time to change the paradigm, and more time to phase out lead's use.
Should anyone want to read a narrative about the intertwined lives of Midgley, Patterson, Kehoe and lead, then this Mental Floss article is a good read. [2]
and still sprayed all around the surrounding land at almost every airport in the USA and worldwide from prop aircraft exhaust despite knowing ANY amount is toxic and irreversible for 30+ years
Also UL94 (https://www.swiftfuelsavgas.com/) could be used in many models. Unfortunately some have been previously upgraded to high-compression engines to get a few more horsepower and they can't use UL94.
Some can run on ethanol-free 87-octane automotive fuel, generally the low-compression engines that already can run 80/87 aviation fuel.
80/87 and 100/130 leaded fuels are all but unavailable, but 100LL is ubiquitous. There is a chicken and egg problem to make G100UL and UL94 available, which will encourage its use. Even automotive fuel is hard to find at airports, possibly because they don't want the liability of improper fueling. (100LL is compatible with almost every gasoline aircraft engine, the rest are not.)
The G100UL also may have an issue with being too good of a solvent, although the developer insists that's a libel.
Swift Fuels is also supposed to introduce a different type of 100-octane unleaded called 100R that has had good results in testing but hasn't been broadly approved yet.
It was like pulling teeth from a dragon to get the FAA to move forward with G100UL as I understand it, and then they suddenly approved it for just about anything provided they write a supplemental type certificate. So maybe the same will happen when/if 100R is approved and someone will handle the marketing.
Only in piston engines, which are a minority of propeller planes. Most commercial propeller aircraft are turboprops, and they use jet fuel. And diesel engines are slowly taking over from gasoline in piston engines.
Correct. For others reading this though: virtually all piston-engine GA aircraft in the US today are still burning 100LL (leaded), and there are nearly 200,000 of them actively flying.
There is a timeline to transition to UL, but very low collective confidence it'll happen by the 2030 goal.
edit: to the commenter that fired off the reactionary reply and deleted it before I could help you. No, not because "[rich people] won't do the right thing." It's because lead is an anti-knock additive for piston engines, and a safe replacement has to go through unimaginable amounts of testing. Once it's certified, one must still figure out scaling production, distribution, etc. Aviation is a very slow moving industry and regulatory environment, which I'm personally thankful for.
ZERO, thirty years ago when there was definitive proof is it forever and irreversible
all lead exhaust aircraft should have been phased out a decade ago if not two decades ago if they cannot be converted
again, there is no acceptable amount, imagine it being sprayed on you, your car, everywhere
your body tries to process it like calcium and stores it forever
how much damage and disease to you and your family are you willing to accept just so someone can keep using their prop aircraft for another decade to make profit?
yes it's all about the money, it's pretty obvious, if there wasn't profit involved it would have been phased out with cars THIRTY YEARS ago
all that lead sprayed all around the land and on people is FOREVER, it doesn't go away, it doesn't wash away, it doesn't evaporate
25 years ago in the UK, leaded petrol was being phased out but still pretty common. The UK Government was giving people grants to have existing cars converted to run on LPG, so they'd only run on a coke can of petrol for a minute or so on startup then switch over to gas.
Catalytic converters? Don't need 'em! There's no CO or unburnt fuel in the exhaust to catalyse because they run as lean as a vegan's dog!
CO2 emissions? Sure, but the stuff is getting flared off as waste at refineries anyway, and we're not going to stop making plastics and fertilisers any time soon, so may as well extract useful work from burning it!
We could have had incredibly clean cities everywhere by now, by simply keeping older cars on the road and adapting them to run on much cleaner safer fuel.
But there was a problem, an absolute bombshell of a problem. The fatal flaw that killed LPG as a road fuel.
It didn't sell new cars. It didn't sell anyone any debt.
So they came up with "scrappage schemes" where you'd get a couple of hundred quid for your old car, it would get destroyed, and then all you had to do was buy a nice new Cleaner Greener Diesel car instead, at some swingeing rate of interest (expect to pay well over twice the sticker price by the end of it - and no, you didn't get the Scrappage Scheme cash if you didn't take the finance package).
LPG had the same problem as electric cars. In the early years there was no infrastructure and so if you buy one you're an early adopter and you can't actually go anywhere. It took a while to get that infrastructure and now electric cars are useful for most trips. You can use LPG cars to go for most trips in the US even today. However, you better plan ahead because finding a place of fuel is going to require some effort. I had a few LNG stations near me, but they seem to have all been torn out, meaning that never made it.
Gas cars faced the same thing when they first came out but by the time they became used for longer trips there was gas everywhere and in the meantime there was gas at least where you bought the car and so it was good enough for the short trips that bought it for.
Same with cigarettes and asbestos. Everyone knew smokers had shorter lives, but the facts were suppressed because it was inconvenient. Everyone knew asbestos was dangerous, but they put it in every single house for decades because "fire was worse".
Asbestos gets a bit of a bad rap. There's an enormous difference from e.g. asbestos tiles and siding in a house vs loose clumps of insulation at mass scale in large factories and such.
But at some point people decided that any asbestos was an immediate ticket to mesothelioma and had to eradicate it altogether.
Cigarette smoking really got going in the world wars, I understand, especially ww2 when the world had manufacturers serving the effort. The custom is dying with the veterans as everyone knows they have a hall pass for it but the rest of us don’t. So smoking was a shorter life but that hardly matters when you’re deployed in theater.
Yes, the psychological effects of environmental lead last a lifetime. No, they didn’t vote differently, they have always gravitated to actors that promise simple solutions and highlight bad blood and animus.
They didn’t vote differently. There were a larger number of the greatest generation that were more comfortable with shared sacrifice in service of society and less entitled like the baby boomers are.
Read charitably, OP isn’t decrying a disagreement on issues as much as the willingness to burn everything down just to see someone else hurt more than oneself. This is present on the left. But it’s uniquely politically actualised by MAGA. (The Democratic Socialists winning elections aren’t seeking to overturn elections or violently storm governing bodies.)
Anytime Thomas Midgley Jr. pops up, I take the opportunity to re-listen to his episode on the Memory Palace. Wonderful bit of historical biography: https://thememorypalace.us/butterflies/
> This, my dear friend, is all I can at present recollect on the Subject. You will see by it, that the Opinion of this mischievous Effect from Lead, is at least above Sixty Years old; and you will observe with Concern how long a useful Truth may be known, and exist, before it is generally receiv'd and practis'd on.
> countries where leaded gasoline was—or still is—used
Note: it’s now banned for road vehicles everywhere [1].
[1] https://ourworldindata.org/data-insights/every-country-has-n... Algeria, 2021
…but is exhausting at volume from most small aircraft you see. I say sadly, as an aviation geek; we can do better!
We're working on it, slowly but surely. This has been a known problem for a long time, at least since 2009 if not earlier. GAMI's G100UL was approved as a 100LL replacement in 2022, but there is still some controversy.
Avweb has done a good series of videos on this. There were some real engineering concerns and some typical aviation conservative decision making. But really, it's a tragedy of the FAA fumbling the ball for decades at this point.
https://www.youtube.com/watch?v=9F-WngVMJBQ
https://www.youtube.com/watch?v=Mvse4Xhzwuk
https://avweb.com/features/unleaded-avgas-airport-playbook-l...
https://avweb.com/aviation-news/judge-denies-g100ul-motion/
https://g100ul.com/
The major proponent was also known as
Thomas Midgley Jr.: Accidentally The Most Dangerous Man Who Ever Lived[0]
Leaded gas, CFCs, and accidentally created a machine that ended his own existence.[1]
[0]https://allthatsinteresting.com/thomas-midgley-jr [1]https://en.wikipedia.org/wiki/Thomas_Midgley_Jr.
> The Most Dangerous Man Who Ever Lived
The titles like annoy me to no end.
Because Thomas Midgley was an engineer. Not overlord of General Motors. Not director. Not even a large shaholder.
GM Leadership knew effects of TEL. And for decades traded everyone's health for their profits. Midgley is complicit, but he's just a small piece.
People who absolve engineers of all responsibility annoy me to no end. They're omnipresent on this forum and justify working for Facebook with things like "not my decision" or "someone else would do it" or "it's not that bad you just don't understand" or "I'm just following orders"
I had one purple link on that second Wikipedia page, which (macabre as it sounds) was very interesting to read through: https://en.wikipedia.org/wiki/List_of_inventors_killed_by_th...
Also leads to another great list-of-lists; https://en.wikipedia.org/wiki/Lists_of_unusual_deaths
> Accidentally
Based on the OP, it wasn't at all accidental. They knew it was dangerous and chose it because they could make more money than with safer alternatives such as ethanol.
I don't think he really appreciated the danger of lead. Its acute toxicity was well-known, but not its chronic toxicity.
And plenty of stuff is toxic in large quantities but harmless (or even vital!) in small quantities.
Interesting - what is that based on?
He's not some incidental commentator. He's an engineer and a principle force behind this technology. He is responsible for the outcomes - 'I didn't know' is reckless negligence. And if there were clear acute problems, chronic problems weren't hard to guess at for anyone, much less an engineer, with all those resources, working on it for years.
> engineer and a principle force behind this technology
well he's not some biochemist...
and even biochemists have trouble within their own field because there's so much 'unknown' stuff in biochem (eg Thalidomide scandal)
A good Veritasium video on the subject:
https://youtu.be/IV3dnLzthDA?is=MorITIg_MvFrKtvR
Lucas Reilly's Mental Floss article on Clair Patterson https://www.mentalfloss.com/science/environment/clair-patter... is a much better piece. I'll also recycle https://news.ycombinator.com/user?id=heymijo 's old comment https://news.ycombinator.com/item?id=28502232 on this article from its 2021 HN discussion https://news.ycombinator.com/item?id=28500508 (again, what follows is his or her work not mine!):
> Two beliefs became entrenched:
1. that lead is natural to the human body, and
2. that a poisoning threshold for lead existed
Robert Kehoe, working for GM, was the chief advocate for leaded gasoline, and really the only person/lab doing research on lead until Clair Patterson stumbled into it while measuring the age of the earth. [0,1]
A modern equivalent might be if Facebook was the only organization researching social media's impact on society, while being able to set the paradigm/assumptions about said safety for half a century.
So even when Patterson's research was published in 1965, it took time to change the paradigm, and more time to phase out lead's use.
Should anyone want to read a narrative about the intertwined lives of Midgley, Patterson, Kehoe and lead, then this Mental Floss article is a good read. [2]
[0] https://en.wikipedia.org/wiki/Robert_A._Kehoe
[1] https://en.wikipedia.org/wiki/Clair_Patterson#Campaign_again...
[2] https://www.mentalfloss.com/science/environment/clair-patter...
For an animated version of this story, see Cosmos, season 2 (I forget which episode, but it was helpful in teaching about this in high school)
https://www.space.com/25579-cosmos-recap-earth-age-lead-pois...
https://en.wikipedia.org/wiki/The_Clean_Room
We've known about climate change for more than a century, but we're pigs, we don't care.
Yes and the toxic effects of asbestos had been known for thousands of years before popcorn ceilings became a fad
and still sprayed all around the surrounding land at almost every airport in the USA and worldwide from prop aircraft exhaust despite knowing ANY amount is toxic and irreversible for 30+ years
* https://www.nbcnews.com/business/business-news/leaded-gas-wa...
Very true that only recently, a lead-free substitute was available.
https://g100ul.com/
Also UL94 (https://www.swiftfuelsavgas.com/) could be used in many models. Unfortunately some have been previously upgraded to high-compression engines to get a few more horsepower and they can't use UL94.
Some can run on ethanol-free 87-octane automotive fuel, generally the low-compression engines that already can run 80/87 aviation fuel.
80/87 and 100/130 leaded fuels are all but unavailable, but 100LL is ubiquitous. There is a chicken and egg problem to make G100UL and UL94 available, which will encourage its use. Even automotive fuel is hard to find at airports, possibly because they don't want the liability of improper fueling. (100LL is compatible with almost every gasoline aircraft engine, the rest are not.)
The G100UL also may have an issue with being too good of a solvent, although the developer insists that's a libel.
Swift Fuels is also supposed to introduce a different type of 100-octane unleaded called 100R that has had good results in testing but hasn't been broadly approved yet.
It was like pulling teeth from a dragon to get the FAA to move forward with G100UL as I understand it, and then they suddenly approved it for just about anything provided they write a supplemental type certificate. So maybe the same will happen when/if 100R is approved and someone will handle the marketing.
You say that in the past tense... But pretty much every propeller plane worldwide still uses the stuff...
Only in piston engines, which are a minority of propeller planes. Most commercial propeller aircraft are turboprops, and they use jet fuel. And diesel engines are slowly taking over from gasoline in piston engines.
Correct. For others reading this though: virtually all piston-engine GA aircraft in the US today are still burning 100LL (leaded), and there are nearly 200,000 of them actively flying.
There is a timeline to transition to UL, but very low collective confidence it'll happen by the 2030 goal.
edit: to the commenter that fired off the reactionary reply and deleted it before I could help you. No, not because "[rich people] won't do the right thing." It's because lead is an anti-knock additive for piston engines, and a safe replacement has to go through unimaginable amounts of testing. Once it's certified, one must still figure out scaling production, distribution, etc. Aviation is a very slow moving industry and regulatory environment, which I'm personally thankful for.
PDF (77pgs): https://download.aopa.org/advocacy/2026/2026-01_Draft-Unlead...
the amount of lead that is acceptable is ZERO
ZERO, thirty years ago when there was definitive proof is it forever and irreversible
all lead exhaust aircraft should have been phased out a decade ago if not two decades ago if they cannot be converted
again, there is no acceptable amount, imagine it being sprayed on you, your car, everywhere
your body tries to process it like calcium and stores it forever
how much damage and disease to you and your family are you willing to accept just so someone can keep using their prop aircraft for another decade to make profit?
yes it's all about the money, it's pretty obvious, if there wasn't profit involved it would have been phased out with cars THIRTY YEARS ago
all that lead sprayed all around the land and on people is FOREVER, it doesn't go away, it doesn't wash away, it doesn't evaporate
I'm unclear who you're arguing with. I don't fly GA and I live under the approach to a GA airport, which is why I'm well-read on this subject.
25 years ago in the UK, leaded petrol was being phased out but still pretty common. The UK Government was giving people grants to have existing cars converted to run on LPG, so they'd only run on a coke can of petrol for a minute or so on startup then switch over to gas.
Catalytic converters? Don't need 'em! There's no CO or unburnt fuel in the exhaust to catalyse because they run as lean as a vegan's dog!
CO2 emissions? Sure, but the stuff is getting flared off as waste at refineries anyway, and we're not going to stop making plastics and fertilisers any time soon, so may as well extract useful work from burning it!
We could have had incredibly clean cities everywhere by now, by simply keeping older cars on the road and adapting them to run on much cleaner safer fuel.
But there was a problem, an absolute bombshell of a problem. The fatal flaw that killed LPG as a road fuel.
It didn't sell new cars. It didn't sell anyone any debt.
So they came up with "scrappage schemes" where you'd get a couple of hundred quid for your old car, it would get destroyed, and then all you had to do was buy a nice new Cleaner Greener Diesel car instead, at some swingeing rate of interest (expect to pay well over twice the sticker price by the end of it - and no, you didn't get the Scrappage Scheme cash if you didn't take the finance package).
And you see how well that worked out.
LPG had the same problem as electric cars. In the early years there was no infrastructure and so if you buy one you're an early adopter and you can't actually go anywhere. It took a while to get that infrastructure and now electric cars are useful for most trips. You can use LPG cars to go for most trips in the US even today. However, you better plan ahead because finding a place of fuel is going to require some effort. I had a few LNG stations near me, but they seem to have all been torn out, meaning that never made it.
Gas cars faced the same thing when they first came out but by the time they became used for longer trips there was gas everywhere and in the meantime there was gas at least where you bought the car and so it was good enough for the short trips that bought it for.
That was kind of it. Until maybe five years ago, every branch of Morrison's had two LPG pumps at their petrol stations, as did Asda.
Now it's mostly wholesale fuel suppliers that have pumps.
Some previous discussion:
2021 https://news.ycombinator.com/item?id=28500508
Same with cigarettes and asbestos. Everyone knew smokers had shorter lives, but the facts were suppressed because it was inconvenient. Everyone knew asbestos was dangerous, but they put it in every single house for decades because "fire was worse".
And don't even get me started on DDT and teflon.
Asbestos gets a bit of a bad rap. There's an enormous difference from e.g. asbestos tiles and siding in a house vs loose clumps of insulation at mass scale in large factories and such.
But at some point people decided that any asbestos was an immediate ticket to mesothelioma and had to eradicate it altogether.
Cigarette smoking really got going in the world wars, I understand, especially ww2 when the world had manufacturers serving the effort. The custom is dying with the veterans as everyone knows they have a hall pass for it but the rest of us don’t. So smoking was a shorter life but that hardly matters when you’re deployed in theater.
> The custom is dying with the veterans
You might want to update your knowledge.
As of 2024, the cigarette smoking rate among U.S. adults is 9.9%, which is an all-time low.
i'm fairly certain the reason trump was elected is the long tail of leaded gasoline; the timing fits pretty well.
Why did these same people vote differently earlier? Does the effect of leaded gasoline show up later in life?
And does not explain all the young men voting for him.
Yes, the psychological effects of environmental lead last a lifetime. No, they didn’t vote differently, they have always gravitated to actors that promise simple solutions and highlight bad blood and animus.
It doesn't happen overnight. It takes time to weaken a strong country to the point where a reality show buffoon can become president.
They didn’t vote differently. There were a larger number of the greatest generation that were more comfortable with shared sacrifice in service of society and less entitled like the baby boomers are.
now let's dig up some old timey polls and see how the greatest generation felt about the issues you hold dear :)
Read charitably, OP isn’t decrying a disagreement on issues as much as the willingness to burn everything down just to see someone else hurt more than oneself. This is present on the left. But it’s uniquely politically actualised by MAGA. (The Democratic Socialists winning elections aren’t seeking to overturn elections or violently storm governing bodies.)
Why is this surfacing up?
hmm good question.
The guy that invented spent years bed-ridden because of it... yet he still went to trade shows to show it off
He was bedridden because of Polio.
https://news.ycombinator.com/item?id=48872443
Anytime Thomas Midgley Jr. pops up, I take the opportunity to re-listen to his episode on the Memory Palace. Wonderful bit of historical biography: https://thememorypalace.us/butterflies/
And he also invented CFCs
“What don’t kill you makes you more strong”.
The Man Who Accidentally Killed The Most People In History
https://www.youtube.com/watch?v=IV3dnLzthDA
> This, my dear friend, is all I can at present recollect on the Subject. You will see by it, that the Opinion of this mischievous Effect from Lead, is at least above Sixty Years old; and you will observe with Concern how long a useful Truth may be known, and exist, before it is generally receiv'd and practis'd on.
> Benjamin Franklin, 1786