Didn't they just legalize unleaded avgas very recently? After a multi-decade regulatory review process?
Seems odd that they were so hesitant to legalize it and now that they did, it becomes the only option!
It's not odd, it's exactly what you'd expect. The only odd thing is that it took this long.
Many (older) aircraft engines need leaded fuel.
You still have to apply for and buy an STC for your specific airframe's serial number and engine's serial number. Then you have to add some paperwork to the logbook and POH and add placards to the fuel fillers and cockpit.
In theory you should be able to automatically get it for anything which was approved from the factory to use 100LL, but the STC application form (here: https://stc.g100ul.com/aircraft/) does not allow you to select most mid-century large radials (which were usually originally certified on 130) or the airplanes they were installed on.
To be clear, this is a great thing, but you can't legally just fill G100UL in any random airplane.
I don't think it needs to work in every conceivable 100LL aircraft: just almost all. Every is a high bar.
Airports don’t always have the space for a second avgas tank (if this is the in between option), and if they did don’t necessarily want to spend money on setting up that infrastructure. So the current catch-all is to provide leaded which is cheaper and guaranteed to work in everything.
I think it’s great we are getting this forced through - it will make the approval process streamlined (like loda was) and removes a major reason people used to push airport shutdowns.
Lots of airports are owned or regulated by local governments which might want to move that single tank to just unleaded. E.g. Santa Clara County banned 100LL at local airports.
Forklift upgrades suck, too. You're best off getting some of the way along and then forklift. Arguably we're reaching that point.
The TC says you must run 100LL. The STC says you can freely mix G100UL in any ratio. The legal/certification problem is solved.
Like small planes are spewing lead over everywhere they’re flying. I’m glad this is happening.
I don’t really care about small operators vs the health of everyone else, and especially kids in the case of lead.
Operating a plane is a privilege, not a right.
Oh, we aren't talking about tire dust? Never mind.
Unlike lead, we've only recently had the technology to measure and quantify tire wear pollution. For example, we didn't realize until 2020 that 6PPD - already toxic to many aquatic organisms - can oxidize become 6PPD-quinone, which is acutely toxic to coho salmon and some other fish species. This solved a 20 year old mystery of so many coho salmon died after a rain storm.
That's why the California Environmental Protection Agency has passed a rule requiring tire makers to declare an alternative by 2024. https://dtsc.ca.gov/scp/motor_vehicle_tires_containing_6ppd/
That's in addition to the particulate pollution from tire wear. ("Research from Emissions Analytics shows that particulate mass emissions from tire wear is thousands of times greater than those from tailpipes, which have been vastly reduced in recent years by high-efficiency exhaust filters." - https://edition.cnn.com/2022/08/16/world/tyre-collective-mic... ).
We of course need to regulate them better because electric cars are heavier, so tire particulate pollution is expected to increase over the next few years.
There's also brake pad pollution, like the EPA's Copper-Free Brake Initiative to remove copper, "mercury, lead, cadmium, asbestiform fibers, and chromium-six salts in motor vehicle brake pads." https://www.epa.gov/npdes/copper-free-brake-initiative . That's a voluntary program, but California and Washington have mandatory requirements.
I trust that you support these efforts to reduce car pollution, and are not simply using the lack of discussion about them in this thread in order to score internet points for implied hypocrisy?
Both tires and brakes have the advantage that they are replaced every few years/decade, so regulations can target manufacturers. An aircraft engine can have decades of life, so any costs of switching away from leaded fuel are felt directly by the owner.
They’ve also been known as a class as a problem (along with catalytic converter particles) for well over 30 years.
There have been multiple studies linking proximity to freeways with asthma and decreased life span, serious health issues like COPD, and even significant increases in sudden unexplained deaths.
45 million Americans live within the high risk zones (300 feet or meters, I forget), countless new daycares, old folks homes, and residential high rises get built there every day, and almost every American is exposed significantly due to being in vehicles on average of an hour a day with insufficient filtering.
[https://www.epa.gov/sites/default/files/2015-11/documents/42...]
The issue here isn’t that aircraft engines last ‘decades’.
It’s that aircraft owners are only legally allowed to use fuels approved by the FAA for their aircraft, and per the various authorizations for their aircraft. Which vary. The engines may get rebuilt, but without a very expensive type change and approval (often from the manufacturer) they’re the same design as the original. Which has the same limitations.
So until there is a viable authorized replacement (per the FAA), literally they can’t use it except in emergencies. Which only just became available. And they can’t change engines either. And they can’t just YOLO it legally.
Because fuel is a major cause of crashes that kill people already (usually contamination, or wrong fuel causing engine failures/flameouts).
And despite the FAA knowing of the risks of lead (or more precisely, knowing the various factors), they only recently did authorize a replacement.
So it’s as if that study on those plastics happened 30 years ago, and we’re just now getting around to it. Which essentially is what has happened with cars and the various pollution.
So raking anyone over the coals when a far larger, more damaging, and widespread crisis has always been going on for even longer and gets ignored? Yeah I’m pointing out the hypocrisy.
It’s always about resources in proportion to risk, and arguably the FAA has dumped far more resources and mitigated a far less damaging risk (in many concrete ways) far faster with this leaded fuel issue than one near and dear all of us.
Which also drives the call to reduce car use, wherein someone is also likely to point out that driving is not a right but a privilege.
> So it’s as if that study on those plastics happened 30 years ago, and we’re just now getting around to it. Which essentially is what has happened with cars and the various pollution.
Yes. And lead wasn't banned for interior paint until decades after some other countries. The US regulatory system is strongly weighted in favor of business over health and environment.
> raking anyone over the coals
As if! This is finding. The EPA must then "propose and promulgate emission standards", which the FAA must then turn into regulations.
It sets no deadlines, it makes no policy changes other than for the EPA and FAA.
I suspect it will take years before the first regulations appear, and with years to allow a changeover.
>Will I have to modify my engine or aircraft to use G100UL avgas?
>Other than placards, no modifications are required. A small placard is attached to the engine and "stick-on" placards are applied to refueling ports. In addition, there is a short POH supplement added to the AFMS.
"Regulations are the only way to solve market externalities" is not the same statement as "All regulations solve market externalities".
The market can never solve market externalities, by definition.
The vast majority of regulations don't work. At least not if your definition of "work" is to actually solve market externalities. But they're great for job security for regulators and politicians.
> The market can never solve market externalities, by definition.
This is not correct. Markets can solve externalities, through market transactions that shift ownership so that the externalities are internalized. The main thing preventing this is government regulation that raises transaction costs so that the necessary adjustments cannot be made. This has been known at least since Ronald Coase published his famous theorem.
In other words, government regulators prevent markets from solving externalities, and then complain that markets can't solve externalities so government regulators have to step in.
It's true that there are cases where there are no market transactions that can internalize an externality. But in those cases, regulation can't solve them either; there are no solutions for such cases. Welcome to the real world.
While this is often true, that doesn't mean it's actually an improvement.
Anyone commercial already has to go in for 100hr inspections all the damn time. The STC is unlikely to cost much relative to that, nor to add much additional hassle.
Anyone private can deal with it, they own their own plane and knew it wasn’t going to be a cheap hobby going in.
G100UL will cost a bit more than 100LL but it seems likely this will change a bit as it becomes more widely used.
I guess it puts people operating midcentury radials that haven’t yet been certified for G100UL in a weird spot.
Same thing with running certain large piston airplane engines on 100. They blow up.
> There are several options that involve no lead, generally substituting with ethanol
Ethanol is corrosive to aluminum. Thankfully airplane designers have never used aluminum in airplanes...
I’ve actually never experienced the, “California gas sucks” issue that car people from the mid-west talk about, have never had an issue with it. ¯\_(ツ)_/¯
Not that it matters when everything made for "premium" is tuned for 91 from the factory anyway, not 93
1) Few refineries make it, so it's MUCH more expensive. But if you're living in California, it is easy to miss because EVERYTHING is much more expensive.
2) Mileage is generally poorer, due to the mandatory ethanol mixes. But some places also usually mix in ethanol, and the difference is usually in the 10-15% range. So unless you have a good A/B comparison going, it's also easy for it to blend in with all the stop and go driving, and terrible road conditions.
3) Mandatory Ethanol means generally very poor storage characteristics. Which considering how much driving happens in California (and how dry the climate is in the populated areas), most people won't notice.
So does it suck? Comparatively, definitely! Is it likely to be noticed unless you're very aware and have experience with other options? Nope.
In the case of my vehicle it results in low/rough idle and positive fuel tank pressure which otherwise do not occur either at lower elevation or with ethanol-free fuel at elevation.
No idea about 240z specifically, but at least things designed for sustained high performance (like aero engines) tend to use valve seats made from some wear and temperature resistant alloy like stellite or brightray.
The recently developed G100UL unleaded fuel requires a change to the type certificate of the airplane (by serial number) and engine(s) (by serial number) to be legal.
Until that supplemental type certificate existed, these airplanes did legally need leaded fuel.
> Once it's legal
exception above.
If you can run, 100LL, you can run G100UL. The main issue is with mogas (standard car gas) - many aviation engines can't run it.
Another aspect is that many piston airplane engines need high octane because they have relatively high compression ratios: WWII era engines need 130 octane to develop full horsepower (they can be operated at reduced manifold pressure on currently available 100 low-lead gas), and even many post-war civilian engines require 100 octane.
Still another aspect is that the FAA is relatively conservative and doesn't want to approve something that might lead to, for example, vapor lock or fuel freezing issues.
I mean, high octane and compression relative to other 1960s engines. The common engines in nearly any single prop cessna have about a 9:1 compression ratio, which was massive back when it was built, but laughably bad compared to anything manufactured after the advent of Fuel injection and better piston geometry.
Modern cars regularly have over 12-1 compression ratios on 87 octane.
1960s era carbs and top ends were just abysmal and did a terrible job of mixing the fuel and air charge and controlling the flame front, because we just didn't have the kinds of computer controls and fluid dynamic simulations we have now, to dynamically prevent knock.
Rotax engines are modern and can reach identical performance figures or better, with the same weight or lighter, simply by using modern techniques like fuel injection or a small turbocharger. They do this while running on 91 octane
In the mean time, rebuilds have to meet the existing design. Which has specific standards.
It's not like Cessnas themselves can't be wildly improved on in general!
As an old Boeing engineer friend of mine used to say 'when the weight of the paperwork exceeds the gross weight of the plane, it will fly.'.
2) Lack of solid quality control relative to aviation fuels (see #1)
3) Power to weight ratio matters a LOT in aviation, and aviation engines run at typically far higher elevations for at least part of their flight time. So aircraft engines generally push things harder, have higher compression, and can be damaged more easily with 'junk' or contaminants.
[0]: https://www.bloomberg.com/news/newsletters/2023-10-12/fake-p...
[1]: https://www.bloomberg.com/news/features/2023-10-11/fake-part...
I'll be doing it, as soon as our home base carries it for my 56 o200.
AVWeb did a couple videos on the subject here:
More specifically, I believe they certified that a particular fuel as suitable for use in ALL engines that previously relied on leaded fuel. Until that happened there was a somewhat legit concern about banning leaded fuel. What people are afraid of now is a monopoly on the new fuel leading to higher prices. But there's already a near monopoly on leaded avgas.
It would be really cool if someone developed a new aircraft engine suitable for replacing all the old models and able to run on a wide range of fuels (this may actually exist). But even then its a slog to get that engine certified for all the planes you'd want to use it on.
As a recent article here talked about, nobody is making new aircraft for general aviation. Or at least, nobody is making anything innovative for it.
But there exist plenty of engines that are good enough for planes and can run on a wide range of fuels. They are just not getting into GA planes.
If you can afford private aviation, the price of the fuel is not going to be a big concern. It's already $7-10/gallon and that is a pretty small component in the all-in hourly costs of operating an aircraft.
Except that they did approve a lead-free fuel for use in all those engines last year. Banning leaded fuel is the obvious next step.
I have never flown to an airport with it yet. i have probably landed in over a dozen different airports in the last few months with a leaded gas engined plane.
What is $250 in aviation terms? It's nothing.
Availability of fuel is a concern, sure. But a fire has to be lit on people's ass, otherwise they will not move.
> The FAA signed on September 1 supplemental type certificates that allow General Aviation Modifications Inc.’s 100-octane unleaded fuel (G100UL) to be used in every general aviation spark-ignition engine and every airframe powered by those engines.
All piston engines and aircraft are certified for G100UL.
There is now a legal alternative. Working as intended.
Edit, looks like there is an alternative https://news.ycombinator.com/item?id=38040091
It's already nearly choked to death by regulation, but that was a step too far.
But they also clearly have been working to mitigate it, and now that they have an alternate are banning leaded avgas and launching it.
So what is your rant about exactly?
Do you even see it in the list?
This NIH study shows it as ‘small, but significant’ - accounting for anywhere from 2.1-4.4% of the lead found in children’s blood near piston airports.
https://ehp.niehs.nih.gov/doi/10.1289/ehp.1003231
Less than 5% of the amount of lead total in their blood from that source, literally for the highest risk segment you can find. Even if completely eliminated, the other 95% isn’t going anywhere.
Even if you don’t average it out across the population, it’s hard to argue that isn’t so close to zero that nearly any significant benefit anywhere else would make it not a rush.
Most airborne lead pollution now is industrial anyway, and that is clearly the calculus there. As is the #1 and #2 sources of lead ingestion for children, old paint and old pipes.
I’m glad they’re getting rid of it, but I’m not going to complain they didn’t drop everything to rush it. Especially since if they did, they’d almost certainly kill more people in the resulting plane crashes.
If general aviation were to be banned, then as commercial pilots die off or retire, it would be difficult to hire new commercial pilots with as much experience as new commercial pilots have historically had.