6 ms·

Wait, wasn’t leaded gas banned in the 70s? Are you telling me all these aircraft that fly over my house are filling the air with lead? How much environmental

Wait, wasn’t leaded gas banned in the 70s? Are you telling me all these aircraft that fly over my house are filling the air with lead? How much environmental lead contamination are we talking here?

sojournerc 3y ago
Not all planes, just older ICE powered prop planes. Jets (and turbo-props) run on kerosene basically. The lead is an additive that acts as a lubricant and older engines aren't certified to run without it.
- ledauphin 3y ago
  it's not actually primarily a lubricant, it's an octane-increaser (detonation reducer)
  - sojournerc 3y ago
    IIUC, it's both, but you're right lubrication is not it's primary purpose, but I think the reason leaded fuel is hard to replace is that the lubricating properties are difficult to replicate. > wherein it served as an effective antiknock agent and reduced exhaust valve and valve seat wear. https://en.m.wikipedia.org/wiki/Tetraethyllead https://en.m.wikipedia.org/wiki/Tetraethyllead
    - jabl 3y ago
      That's mostly an issue on cheap engines without hardened valve seats. Aviation engines switched to hardened valve seats well before WWII.
- pc86 3y ago
  "older ICE powered prop planes" in this context means any prop plane, and about 95% of those used for GA. Brand new ones require leaded gasoline as well because with the exception of fuel injection the engine designs are basically identical to those 50s and 60s era planes.
  - sojournerc 3y ago
    Being pedantic, but turbo-prop planes use a jet engine to turn the propeller, and so use jet fuel. That's going to be bigger twins and prop planes like the Pilatus
    - froggit 3y ago
      Being more pedantic, turboprops use gas turbine engines to power the propeller. "Jet engine" is incorrect when referring to gas turbine engine other than turbojets, such as turboprops, turbofans and turboshafts. Turbojets were the first variant of gas turbine engine to be put into use so "jet engine" ended up being used as a common term. Modern "jet planes" often use turbofans for their greater efficiency at similar performance levels, but "fan plane" sounds silly. The M1 Abrams uses a turboshaft engine but I've never heard it called a "jet tank" (which sounds badass).
      - sojournerc 3y ago
        I appreciate the double pedantry. I should've known intuitively that a turboprop isn't a jet engine because the thrust comes from the prop not the exhaust.
        lazide 3y ago
        Unrelated pedantry - even still, significant thrust does come from the jet engine. 5-10% typically.
  - Reason077 3y ago
    They don't require leaded gasoline, they require 100-octane gasoline. It's just that until recently, a certified, unleaded 100-octane avgas did not exist.
c4mpute 3y ago
Double or triple that of a car, for a small plane, because of the higher fuel consumption. But this only affects avgas, which is high-octane gasoline for propeller-driven aircraft. Jet-A1, which is light diesel fuel or kerosene-like for jets doesn't contain lead.
m0shen 3y ago
Not all. Jet fuel doesn't have lead. AFAIK it's piston based small planes.
some_random 3y ago
Until very recently, you legally weren't allowed to fly most GA aircraft on anything other than 100LL. Thank the FAA for dragging their feet on certifying a replacement.
NelsonMinar 3y ago
Yup. Old small piston airplanes had an exemption to use leaded gas "for safety". Mind you, these are the engines running on 1950s tech that still have carburetors. The failure to test and approve an unleaded fuel lead is a long and unpleasant story.
- pc86 3y ago
  I mean, brand new single-engine prop planes with modern fuel-injection systems are also running on leaded gas, so the fact that really old planes also are is kind of obvious/irrelevant. With a handful of exceptions, single-engine prop planes are only certified to run on 100-octane leaded gasoline. For many (maybe even most, but I don't know the exact numbers) certified aircraft there is no legal path to get it to run on any other type of fuel. Certain planes have supplemental type certificates to allow an expensive conversion but it's far from the norm.
  - BorgHunter 3y ago
    > With a handful of exceptions, single-engine prop planes are only certified to run on 100-octane leaded gasoline. This was true up until last year, when G100UL was approved as a drop-in replacement for 100LL. It does require a STC and the associated paperwork, but this is apparently pro forma and quite cheap, and doesn't require any modification to the aircraft apart from some placards. The problem, of course, is that G100UL isn't really available anywhere yet, while 100LL is still ubiquitous.
  - dontlaugh 3y ago
    There are 100 RON fuels without lead.
    - jabl 3y ago
      Sure there are, but the 100 in 100 octane avgas refers to MON, not RON. 100 MON fuel is a bit trickier to be done without lead, although we now have G100UL which does it.
  - Reason077 3y ago
foxyv 3y ago
Not much thankfully. It's only small General Aviation piston aircraft and there aren't many of them relatively speaking. It's not like in the 60s when there were thousands of car engines per city constantly pumping it out. More like 10-20. This is why the FAA wasn't in a huge hurry but at the same time they were WAY too slow. It should have been a crash priority honestly.
- londons_explore 3y ago
  It's likely that every kilogram of lead you atomize into the air has a far worse impact on people and the environment than a kilo of lead in, for example, electronics, paint, or flashing. Increased lead in crops grown within a few miles of airports has been noticed.[1]. As had reduced IQ's in children living near airports. [2] [1]: https://core.ac.uk/download/pdf/344932499.pdf https://core.ac.uk/download/pdf/344932499.pdf [2]: https://www.newscientist.com/article/2353962-children-living-near-airport-found-to-have-raised-lead-levels-in-blood/ https://www.newscientist.com/article/2353962-children-living...
  - foxyv 3y ago
    Yeah, they should have ended 100LL a long long time ago. It's crazy how such a small amount can cause so many problems. Imagine what it was like back in the 60s. Utter insanity and they KNEW that it would cause problems.
    - londons_explore 3y ago
      Unfortunately there is growing evidence that lead stays in soils for decades or maybe centuries. I can imagine in the future that lead contamination of farmland might mean that we end up with a kinda crazy reversal - we end up growing all our food in undeveloped places like south america that never had as much lead contamination, and food from the USA and other developed countries is so lead contaminated that it gets exported to places like africa where they don't have strict regulations against contaminated food.
      - 3y ago
uoaei 3y ago
Concentrated near takeoff and approach paths of small airports servicing small aircraft. https://qz.com/2158594/do-you-live-near-enough-to-a-small-airport-to-have-lead-exposure#interactive-maps https://qz.com/2158594/do-you-live-near-enough-to-a-small-ai...
- pc86 3y ago
  Can anyone get this page to work? I typed in about a dozen different airports I've flown into and not a single one shows up, but if I type random characters I can get some airports to show. This could be an incredibly useful tool if it worked (and wasn't limited to just a few years worth of data).
  - nonsense123 3y ago
    Nope. the url for the widget in the frame is https://things.qz.com/2022/leaded-gas-in-aviation/index.html?c=004 https://things.qz.com/2022/leaded-gas-in-aviation/index.html... but nothing works
s17n 3y ago
> How much environmental lead contamination are we talking here? Not much. Flying is a pretty niche hobby (and as others have pointed out, commercial jets don't use leaded fuel).
- miguelazo 3y ago
  In some areas, especially highly populated areas like Southern California, it is far from a "niche hobby".
rtkwe 3y ago
Yes and there's some areas near popular flight schools with significantly elevated lead levels because there are constantly planes flying overhead using leaded Avgas. It was a special carveout because recertifying every engine that was designed to use leaded gas is a pretty big lift and has significantly higher safety implications when the engine is in a plane instead of a car. It is only for some types of engines but those are more common on the older more affordable planes.
- nonsense123 3y ago
  > recertifying every engine that was designed to use leaded gas is a pretty big lift ... instead of a car Wrong on all accounts. There are orders of magnitude less engine models used in air than cars. Profit margin for airplane companies are higher than cars (though volume is much lower). cars use the same model worldwide and pass certification all at once, planes sell in one country and customers are mostly responsible for 'acclimatization' or whatever they call it in your parts, but it usually is about lights color and placements or some nonsense. the one thing that made planes be so slow, is that people who own planes have much more voice over legislation than people who own cars. Nothing else. That's why the whole industry used tax payer money to certify one special new gas type that will work on all existing engines (again, possible because much less variety, making it easier technically). You breathed lead for 60 years of legal lethargy just so a few people didn't have to spend a few pennies on their plane maintenance.
  - rtkwe 3y ago
    If a car engine fails or is suffering more long term damage due to knocking the car doesn't have an immediate emergency on the same order of magnitude a plane does. A failed plane engine is an immediate life threatening emergency to everyone on board.
    - elzbardico 3y ago
      Not only on board. I thanks the FAA and other's countries flight authorities for the fact that I don't need to have an anxiety crisis every time a plane passes overhead.
codexb 3y ago
No, commercial airplanes all use unleaded jet fuel. But the small, 2 and 4 seater general aviation planes you see are almost all using 60-year old engine designs that run on leaded fuel because the FAA doesn't want to devote time to approving new engines for general aviation.
aaomidi 3y ago
A ton. It’s a shame it’s taken this long. And it’s a shame there are folk here defending leaded fuel.
- stouset 3y ago
  Nobody as far as I can tell is defending leaded fuel. Just explaining why there was initially a carve out. Having that carve out made sense at the time. Having it last until 2023 is malpractice.
- froggit 3y ago
  Pretty sure no one's defending it, just explaining why it stuck around. It seems pretty unanimous "spraying lead everywhere is bad so leaded fuel is bad."
renewiltord 3y ago
Safety regulations are written in blood. There should be a long and careful process before any so-called improvements from modern technology are forced upon us. In making new kinds of gasoline, chemical engineers should really consider safety and ethics. And every one of them should first be required to study the humanities.
- phkahler 3y ago
  >> There should be a long and careful process before any so-called improvements from modern technology are forced upon us. In this case, it has been a decades long process. But it's done now and the replacement fuel is available. Time to mandate the change.
  - renewiltord 3y ago
    Stop making guinea pigs out of normal people. Gasoline is a volatile substance. Just changing it willy-nilly without extensive testing is unethical. There's a reason the FAA hasn't certified it. Safety regulations are written in blood.
    - stouset 3y ago
      GAMI (unleaded 100 octane avgas) has been extensively tested at this point, far more so than was probably warranted.
- froggit 3y ago
  > In making new kinds of gasoline, chemical engineers should really consider safety and ethics. That's why unleaded fuel came about.
bigmattystyles 3y ago
Is that also in what I’m breathing in when I fly commercial?
- gnicholas 3y ago
  If you're in a jet, no (they use jet fuel).
t90fan 3y ago
> wasn’t leaded gas banned in the 70s? Don't know about the US, but we had leaded petrol (gas) for cars much later here in the UK, ~2000 at least. I remember my mum's Austin Metro (which was from the early 90s/late 80s) ran on it, and we only replaced that car once I was in high school (and that was in 2001)
shrubble 3y ago
Since according to another post in this thread, 11000 barrels of leaded are produced each day, vs 4.9 million barrels of diesel fuel seem to be the numbers, not a huge amount. However it is still good that the law now allows unleaded.
deleted 3y ago
[deleted]

Wait, wasn’t leaded gas banned in the 70s? Are you telling me all these aircraft that fly over my house are filling the air with lead? How much environmental lead contamination are we talking here?

sojournerc 3y ago

Not all planes, just older ICE powered prop planes. Jets (and turbo-props) run on kerosene basically. The lead is an additive that acts as a lubricant and older engines aren't certified to run without it.

ledauphin 3y ago
it's not actually primarily a lubricant, it's an octane-increaser (detonation reducer)
- sojournerc 3y ago
  IIUC, it's both, but you're right lubrication is not it's primary purpose, but I think the reason leaded fuel is hard to replace is that the lubricating properties are difficult to replicate. > wherein it served as an effective antiknock agent and reduced exhaust valve and valve seat wear. https://en.m.wikipedia.org/wiki/Tetraethyllead https://en.m.wikipedia.org/wiki/Tetraethyllead
  - jabl 3y ago
    That's mostly an issue on cheap engines without hardened valve seats. Aviation engines switched to hardened valve seats well before WWII.
pc86 3y ago
"older ICE powered prop planes" in this context means any prop plane, and about 95% of those used for GA. Brand new ones require leaded gasoline as well because with the exception of fuel injection the engine designs are basically identical to those 50s and 60s era planes.
- sojournerc 3y ago
  Being pedantic, but turbo-prop planes use a jet engine to turn the propeller, and so use jet fuel. That's going to be bigger twins and prop planes like the Pilatus
  - froggit 3y ago
    Being more pedantic, turboprops use gas turbine engines to power the propeller. "Jet engine" is incorrect when referring to gas turbine engine other than turbojets, such as turboprops, turbofans and turboshafts. Turbojets were the first variant of gas turbine engine to be put into use so "jet engine" ended up being used as a common term. Modern "jet planes" often use turbofans for their greater efficiency at similar performance levels, but "fan plane" sounds silly. The M1 Abrams uses a turboshaft engine but I've never heard it called a "jet tank" (which sounds badass).
    - sojournerc 3y ago
      I appreciate the double pedantry. I should've known intuitively that a turboprop isn't a jet engine because the thrust comes from the prop not the exhaust.
      - lazide 3y ago
        Unrelated pedantry - even still, significant thrust does come from the jet engine. 5-10% typically.
- Reason077 3y ago
  They don't require leaded gasoline, they require 100-octane gasoline. It's just that until recently, a certified, unleaded 100-octane avgas did not exist.

c4mpute 3y ago

Double or triple that of a car, for a small plane, because of the higher fuel consumption. But this only affects avgas, which is high-octane gasoline for propeller-driven aircraft. Jet-A1, which is light diesel fuel or kerosene-like for jets doesn't contain lead.

m0shen 3y ago

Not all. Jet fuel doesn't have lead. AFAIK it's piston based small planes.

some_random 3y ago

Until very recently, you legally weren't allowed to fly most GA aircraft on anything other than 100LL. Thank the FAA for dragging their feet on certifying a replacement.

NelsonMinar 3y ago

Yup. Old small piston airplanes had an exemption to use leaded gas "for safety". Mind you, these are the engines running on 1950s tech that still have carburetors. The failure to test and approve an unleaded fuel lead is a long and unpleasant story.

pc86 3y ago
I mean, brand new single-engine prop planes with modern fuel-injection systems are also running on leaded gas, so the fact that really old planes also are is kind of obvious/irrelevant. With a handful of exceptions, single-engine prop planes are only certified to run on 100-octane leaded gasoline. For many (maybe even most, but I don't know the exact numbers) certified aircraft there is no legal path to get it to run on any other type of fuel. Certain planes have supplemental type certificates to allow an expensive conversion but it's far from the norm.
- BorgHunter 3y ago
  > With a handful of exceptions, single-engine prop planes are only certified to run on 100-octane leaded gasoline. This was true up until last year, when G100UL was approved as a drop-in replacement for 100LL. It does require a STC and the associated paperwork, but this is apparently pro forma and quite cheap, and doesn't require any modification to the aircraft apart from some placards. The problem, of course, is that G100UL isn't really available anywhere yet, while 100LL is still ubiquitous.
- dontlaugh 3y ago
  There are 100 RON fuels without lead.
  - jabl 3y ago
    Sure there are, but the 100 in 100 octane avgas refers to MON, not RON. 100 MON fuel is a bit trickier to be done without lead, although we now have G100UL which does it.
- Reason077 3y ago

foxyv 3y ago

Not much thankfully. It's only small General Aviation piston aircraft and there aren't many of them relatively speaking. It's not like in the 60s when there were thousands of car engines per city constantly pumping it out. More like 10-20. This is why the FAA wasn't in a huge hurry but at the same time they were WAY too slow. It should have been a crash priority honestly.

londons_explore 3y ago
It's likely that every kilogram of lead you atomize into the air has a far worse impact on people and the environment than a kilo of lead in, for example, electronics, paint, or flashing. Increased lead in crops grown within a few miles of airports has been noticed.[1]. As had reduced IQ's in children living near airports. [2] [1]: https://core.ac.uk/download/pdf/344932499.pdf https://core.ac.uk/download/pdf/344932499.pdf [2]: https://www.newscientist.com/article/2353962-children-living-near-airport-found-to-have-raised-lead-levels-in-blood/ https://www.newscientist.com/article/2353962-children-living...
- foxyv 3y ago
  Yeah, they should have ended 100LL a long long time ago. It's crazy how such a small amount can cause so many problems. Imagine what it was like back in the 60s. Utter insanity and they KNEW that it would cause problems.
  - londons_explore 3y ago
    Unfortunately there is growing evidence that lead stays in soils for decades or maybe centuries. I can imagine in the future that lead contamination of farmland might mean that we end up with a kinda crazy reversal - we end up growing all our food in undeveloped places like south america that never had as much lead contamination, and food from the USA and other developed countries is so lead contaminated that it gets exported to places like africa where they don't have strict regulations against contaminated food.
    - 3y ago

uoaei 3y ago

Concentrated near takeoff and approach paths of small airports servicing small aircraft. https://qz.com/2158594/do-you-live-near-enough-to-a-small-airport-to-have-lead-exposure#interactive-maps https://qz.com/2158594/do-you-live-near-enough-to-a-small-ai...

pc86 3y ago
Can anyone get this page to work? I typed in about a dozen different airports I've flown into and not a single one shows up, but if I type random characters I can get some airports to show. This could be an incredibly useful tool if it worked (and wasn't limited to just a few years worth of data).
- nonsense123 3y ago
  Nope. the url for the widget in the frame is https://things.qz.com/2022/leaded-gas-in-aviation/index.html?c=004 https://things.qz.com/2022/leaded-gas-in-aviation/index.html... but nothing works

s17n 3y ago

> How much environmental lead contamination are we talking here? Not much. Flying is a pretty niche hobby (and as others have pointed out, commercial jets don't use leaded fuel).

miguelazo 3y ago
In some areas, especially highly populated areas like Southern California, it is far from a "niche hobby".

rtkwe 3y ago

Yes and there's some areas near popular flight schools with significantly elevated lead levels because there are constantly planes flying overhead using leaded Avgas. It was a special carveout because recertifying every engine that was designed to use leaded gas is a pretty big lift and has significantly higher safety implications when the engine is in a plane instead of a car. It is only for some types of engines but those are more common on the older more affordable planes.

nonsense123 3y ago
> recertifying every engine that was designed to use leaded gas is a pretty big lift ... instead of a car Wrong on all accounts. There are orders of magnitude less engine models used in air than cars. Profit margin for airplane companies are higher than cars (though volume is much lower). cars use the same model worldwide and pass certification all at once, planes sell in one country and customers are mostly responsible for 'acclimatization' or whatever they call it in your parts, but it usually is about lights color and placements or some nonsense. the one thing that made planes be so slow, is that people who own planes have much more voice over legislation than people who own cars. Nothing else. That's why the whole industry used tax payer money to certify one special new gas type that will work on all existing engines (again, possible because much less variety, making it easier technically). You breathed lead for 60 years of legal lethargy just so a few people didn't have to spend a few pennies on their plane maintenance.
- rtkwe 3y ago
  If a car engine fails or is suffering more long term damage due to knocking the car doesn't have an immediate emergency on the same order of magnitude a plane does. A failed plane engine is an immediate life threatening emergency to everyone on board.
  - elzbardico 3y ago
    Not only on board. I thanks the FAA and other's countries flight authorities for the fact that I don't need to have an anxiety crisis every time a plane passes overhead.

codexb 3y ago

No, commercial airplanes all use unleaded jet fuel. But the small, 2 and 4 seater general aviation planes you see are almost all using 60-year old engine designs that run on leaded fuel because the FAA doesn't want to devote time to approving new engines for general aviation.

aaomidi 3y ago

A ton. It’s a shame it’s taken this long. And it’s a shame there are folk here defending leaded fuel.

stouset 3y ago
Nobody as far as I can tell is defending leaded fuel. Just explaining why there was initially a carve out. Having that carve out made sense at the time. Having it last until 2023 is malpractice.
froggit 3y ago
Pretty sure no one's defending it, just explaining why it stuck around. It seems pretty unanimous "spraying lead everywhere is bad so leaded fuel is bad."

renewiltord 3y ago

Safety regulations are written in blood. There should be a long and careful process before any so-called improvements from modern technology are forced upon us. In making new kinds of gasoline, chemical engineers should really consider safety and ethics. And every one of them should first be required to study the humanities.

phkahler 3y ago
>> There should be a long and careful process before any so-called improvements from modern technology are forced upon us. In this case, it has been a decades long process. But it's done now and the replacement fuel is available. Time to mandate the change.
- renewiltord 3y ago
  Stop making guinea pigs out of normal people. Gasoline is a volatile substance. Just changing it willy-nilly without extensive testing is unethical. There's a reason the FAA hasn't certified it. Safety regulations are written in blood.
  - stouset 3y ago
    GAMI (unleaded 100 octane avgas) has been extensively tested at this point, far more so than was probably warranted.
froggit 3y ago
> In making new kinds of gasoline, chemical engineers should really consider safety and ethics. That's why unleaded fuel came about.

bigmattystyles 3y ago

Is that also in what I’m breathing in when I fly commercial?

gnicholas 3y ago
If you're in a jet, no (they use jet fuel).

t90fan 3y ago

> wasn’t leaded gas banned in the 70s? Don't know about the US, but we had leaded petrol (gas) for cars much later here in the UK, ~2000 at least. I remember my mum's Austin Metro (which was from the early 90s/late 80s) ran on it, and we only replaced that car once I was in high school (and that was in 2001)

shrubble 3y ago

Since according to another post in this thread, 11000 barrels of leaded are produced each day, vs 4.9 million barrels of diesel fuel seem to be the numbers, not a huge amount. However it is still good that the law now allows unleaded.

deleted 3y ago

[deleted]