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Gee if only the FAA could have certified unleaded gas some time in the last 3 decades. It’s not like us GA enthusiasts enjoy depending on an expensive leaded ga

Gee if only the FAA could have certified unleaded gas some time in the last 3 decades. It’s not like us GA enthusiasts enjoy depending on an expensive leaded gas.

nimbius 3y ago
as a diesel engine mechanic ive always figured there was some amazing conspiracy about leaded avgas. Here on the ground, diesel regulations and formulations are basically a yearly theatricality. new scrubbers, new regenerators, fuels you can use and fuels you can never use, and special locations and applications for the fuels if you use them at all. The regulations are pretty rigorously developed and enforced.
- colechristensen 3y ago
  If your standard diesel engine fails it’s generally not a life threatening emergency though so change is much safer. Aviation has safety and regulatory habits written in blood.
  - ethbr1 3y ago
    Aren't most emergency backup generators diesel? Hospitals. Nuclear power plants. Airports. Laboratories.
    - dghlsakjg 3y ago
      Yes, but the GP is posting about diesel engines in over the road equipment. Those regulations don't apply to 1. existing installations in trucks or 2. generators.
    - mschuster91 3y ago
      These are multi redundant and generally hospital patient monitoring systems have additional batteries of their own to make sure people don't die, and in the case of a major clusterfuck there are emergency procedures in which it's specified how power will be restored assuming a grid and backup generator failure (usually it involves the fire department shuttling a generator pack to the hospital site). With engine failures in aircraft however, the consequences can be way more dire - particularly in GA where it's (at least in the US) even being allowed to fly without a license at all (Part 103 ultralights), and forget about regular legit simulator training on what to do in that case.
    - AdamJacobMuller 3y ago
      It's very easy to run emergency backup generators in parallel. Take your total load (10MW) divide by 5 (2MW) and you need 5 2MW generators, buy 7 and run 6/7 and your "down for yearly maintenance" generator can be offline while your "oh shit we installed the wrong fuel filter and the injectors clogged" generator also fails. Much harder in a plane.
      - lazide 3y ago
        Especially since rarely does anyone care about how heavy the emergency generators are. But if you add 100 lbs too much in the wrong place on a GA plane, everyone is almost certainly going to die.
- Gibbon1 3y ago
  I remember conversations about using unleaded gas in aviation 40 years ago. And the pro side's argument is auto grade gasoline is highly regulated with better quality control and standards than leaded aviation gas. And pointed out that cars run just fine at the altitudes light aircraft fly at. SO I hear you on that. It's a bit inane. If there is a conspiracy I suspect it's the government exerts a light hand on things rich people do. What surprises me is the refineries didn't tell the light aviation industry they weren't going to make leaded gas anymore. If they'd done that the Feds would have kicked them some cash to develop an unleaded version.
  - jefftk 3y ago
    > What surprises me is the refineries didn't tell the light aviation industry they weren't going to make leaded gas anymore. You can just add lead to unleaded gas (which was legal until 1996 in the US), so even if you could convince them to be altruistic in this way others could just work around it.
  - mauvehaus 3y ago
    Apart from specialty applications, auto engines run at a small fraction of their full power output the overwhelming majority of the time. Aero engines run at a substantial fraction of their rated power output basically full time[0]. The fact that auto engines can be run on unleaded, lower octane gas at 10,000' or more doesn't really tell us that the same low octane unleaded gas is suitable for an aero application. [0] And in some cases are rated for more power for limited lengths of time such as takeoff. See here, for example https://medium.com/s/story/the-long-way-round-the-plane-that-accidentally-circumnavigated-the-world-c04ca734c6bb https://medium.com/s/story/the-long-way-round-the-plane-that...
- dghlsakjg 3y ago
  Its not so much a conspiracy as just not as big of an issue compared to diesel consumption About 11 thousand barrels of 100ll are produced every day in the US. Compare that to 4.9 million barrels of diesel daily, and you can see why it is a bigger priority. In this case 100ll is a literal drop in the bucket. But also its a rich guy hobby that generally isn't very visible.
samtho 3y ago
One of my friends that helped me build hours does experimental aircraft and just runs his c172 on 91 unleaded from a highway fuel pump. Pretty sure he has a lycoming IO-360M1A on it. He does have to haul fuel in, however.
kube-system 3y ago
It sounds like this is setting the stage for the FAA to be forced to make a move... > the FAA has a statutory mandate to prescribe standards for the composition or chemical or physical properties of an aircraft fuel or fuel additive to control or eliminate aircraft emissions which the EPA has found endanger public health or welfare under section 231(a) of the Clean Air Act. In issuing these final findings, the EPA is making such a finding for emissions of lead from engines in covered aircraft.
JumpCrisscross 3y ago
Unleaded avgas started being approved in 2021, and is now generally approved for all piston aircraft [1]. [1] https://www.aopa.org/news-and-media/all-news/2022/september/01/closer-to-an-unleaded-future https://www.aopa.org/news-and-media/all-news/2022/september/...
- dmitrygr 3y ago
  Only for some engines. Some of the higher compression engines still have no options.
  - deleted 3y ago
    [deleted]
  - sokoloff 3y ago
    That was an interim state. It is now approved for all type-certificated spark-ignition piston engines. https://www.g100ul.com/faq.html#testing https://www.g100ul.com/faq.html#testing
    - dmitrygr 3y ago
      I stand (sit) corrected.
  - londons_explore 3y ago
    Lack of options should never have prevented lead being outlawed. Ask anyone on the street "Would you like to drink this potion making you dumber so that someone else can fly a plane up there" and everyone will say no. Clearly it isn't okay to harm someone without their knowledge or consent.
    - ctennis1 3y ago
      I'm an airplane owner, and I agree. If they had outlawed it, I bet the solution would have come a lot faster.
    - 3y ago
slowhadoken 3y ago
American aviation does need an overhaul. I used to fly with some guys out of a private hanger and a few nearby FBOs. Pilots would occasionally grumble about changes made to flight regulations and airport procedures during the 1980’s. Even the most staunch republican would bad mouth Regan for it.
MilStdJunkie 3y ago
The saga of unleaded avgas has been long, expensive, and slightly ridiculous. It's not just FAA - not by itself, although regulatory capture is, of course, a frickin' plague. You had a big ol' mob of aerospace companies racing to lock in their engine designs for the next forever via mandated fuel specifications. This is the Golden Fleece in this industry: if you can get to write the next mandated spec, you can relax on your money bed for the rest of time.
deleted 3y ago
[deleted]
gwbas1c 3y ago
I bought some unleaded AVGAS in 2017 at an airport in Falmouth, MA. Power tools run much better on it because it contains no ethanol. My portable generator starts much more easily after sitting for a few months if I use AVGAS instead of what I buy at the pump. It's because the ethanol gums up the carbonator.

Gee if only the FAA could have certified unleaded gas some time in the last 3 decades. It’s not like us GA enthusiasts enjoy depending on an expensive leaded gas.

nimbius 3y ago

as a diesel engine mechanic ive always figured there was some amazing conspiracy about leaded avgas. Here on the ground, diesel regulations and formulations are basically a yearly theatricality. new scrubbers, new regenerators, fuels you can use and fuels you can never use, and special locations and applications for the fuels if you use them at all. The regulations are pretty rigorously developed and enforced.

colechristensen 3y ago
If your standard diesel engine fails it’s generally not a life threatening emergency though so change is much safer. Aviation has safety and regulatory habits written in blood.
- ethbr1 3y ago
  Aren't most emergency backup generators diesel? Hospitals. Nuclear power plants. Airports. Laboratories.
  - dghlsakjg 3y ago
    Yes, but the GP is posting about diesel engines in over the road equipment. Those regulations don't apply to 1. existing installations in trucks or 2. generators.
  - mschuster91 3y ago
    These are multi redundant and generally hospital patient monitoring systems have additional batteries of their own to make sure people don't die, and in the case of a major clusterfuck there are emergency procedures in which it's specified how power will be restored assuming a grid and backup generator failure (usually it involves the fire department shuttling a generator pack to the hospital site). With engine failures in aircraft however, the consequences can be way more dire - particularly in GA where it's (at least in the US) even being allowed to fly without a license at all (Part 103 ultralights), and forget about regular legit simulator training on what to do in that case.
  - AdamJacobMuller 3y ago
    It's very easy to run emergency backup generators in parallel. Take your total load (10MW) divide by 5 (2MW) and you need 5 2MW generators, buy 7 and run 6/7 and your "down for yearly maintenance" generator can be offline while your "oh shit we installed the wrong fuel filter and the injectors clogged" generator also fails. Much harder in a plane.
    - lazide 3y ago
      Especially since rarely does anyone care about how heavy the emergency generators are. But if you add 100 lbs too much in the wrong place on a GA plane, everyone is almost certainly going to die.
Gibbon1 3y ago
I remember conversations about using unleaded gas in aviation 40 years ago. And the pro side's argument is auto grade gasoline is highly regulated with better quality control and standards than leaded aviation gas. And pointed out that cars run just fine at the altitudes light aircraft fly at. SO I hear you on that. It's a bit inane. If there is a conspiracy I suspect it's the government exerts a light hand on things rich people do. What surprises me is the refineries didn't tell the light aviation industry they weren't going to make leaded gas anymore. If they'd done that the Feds would have kicked them some cash to develop an unleaded version.
- jefftk 3y ago
  > What surprises me is the refineries didn't tell the light aviation industry they weren't going to make leaded gas anymore. You can just add lead to unleaded gas (which was legal until 1996 in the US), so even if you could convince them to be altruistic in this way others could just work around it.
- mauvehaus 3y ago
  Apart from specialty applications, auto engines run at a small fraction of their full power output the overwhelming majority of the time. Aero engines run at a substantial fraction of their rated power output basically full time[0]. The fact that auto engines can be run on unleaded, lower octane gas at 10,000' or more doesn't really tell us that the same low octane unleaded gas is suitable for an aero application. [0] And in some cases are rated for more power for limited lengths of time such as takeoff. See here, for example https://medium.com/s/story/the-long-way-round-the-plane-that-accidentally-circumnavigated-the-world-c04ca734c6bb https://medium.com/s/story/the-long-way-round-the-plane-that...
dghlsakjg 3y ago
Its not so much a conspiracy as just not as big of an issue compared to diesel consumption About 11 thousand barrels of 100ll are produced every day in the US. Compare that to 4.9 million barrels of diesel daily, and you can see why it is a bigger priority. In this case 100ll is a literal drop in the bucket. But also its a rich guy hobby that generally isn't very visible.

samtho 3y ago

One of my friends that helped me build hours does experimental aircraft and just runs his c172 on 91 unleaded from a highway fuel pump. Pretty sure he has a lycoming IO-360M1A on it. He does have to haul fuel in, however.

kube-system 3y ago

It sounds like this is setting the stage for the FAA to be forced to make a move... > the FAA has a statutory mandate to prescribe standards for the composition or chemical or physical properties of an aircraft fuel or fuel additive to control or eliminate aircraft emissions which the EPA has found endanger public health or welfare under section 231(a) of the Clean Air Act. In issuing these final findings, the EPA is making such a finding for emissions of lead from engines in covered aircraft.

JumpCrisscross 3y ago

Unleaded avgas started being approved in 2021, and is now generally approved for all piston aircraft [1]. [1] https://www.aopa.org/news-and-media/all-news/2022/september/01/closer-to-an-unleaded-future https://www.aopa.org/news-and-media/all-news/2022/september/...

dmitrygr 3y ago
Only for some engines. Some of the higher compression engines still have no options.
- deleted 3y ago
  [deleted]
- sokoloff 3y ago
  That was an interim state. It is now approved for all type-certificated spark-ignition piston engines. https://www.g100ul.com/faq.html#testing https://www.g100ul.com/faq.html#testing
  - dmitrygr 3y ago
    I stand (sit) corrected.
- londons_explore 3y ago
  Lack of options should never have prevented lead being outlawed. Ask anyone on the street "Would you like to drink this potion making you dumber so that someone else can fly a plane up there" and everyone will say no. Clearly it isn't okay to harm someone without their knowledge or consent.
  - ctennis1 3y ago
    I'm an airplane owner, and I agree. If they had outlawed it, I bet the solution would have come a lot faster.
  - 3y ago

slowhadoken 3y ago

American aviation does need an overhaul. I used to fly with some guys out of a private hanger and a few nearby FBOs. Pilots would occasionally grumble about changes made to flight regulations and airport procedures during the 1980’s. Even the most staunch republican would bad mouth Regan for it.

MilStdJunkie 3y ago

The saga of unleaded avgas has been long, expensive, and slightly ridiculous. It's not just FAA - not by itself, although regulatory capture is, of course, a frickin' plague. You had a big ol' mob of aerospace companies racing to lock in their engine designs for the next forever via mandated fuel specifications. This is the Golden Fleece in this industry: if you can get to write the next mandated spec, you can relax on your money bed for the rest of time.

deleted 3y ago

[deleted]

gwbas1c 3y ago

I bought some unleaded AVGAS in 2017 at an airport in Falmouth, MA. Power tools run much better on it because it contains no ethanol. My portable generator starts much more easily after sitting for a few months if I use AVGAS instead of what I buy at the pump. It's because the ethanol gums up the carbonator.