Interesting to see the continued interest in G100UL on Hacker News. Personally I'm ecstatic to soon be able to run unleaded. I'm curious to know if this is indicative of a broader (politically-relevant?) interest in getting lead out of GA, or just the sort of specialist topic that tends to interest HNers.
It's interesting (but not unexpected in hindsight) that this new slew of approvals (generally) only impacts engines previously approved for low-octane unleaded fuels (e.g., 94UL). Even smaller engines like the Lycoming IO-360 (except the derated -L2A) aren't approved despite only modest power increases over the O-360.
At any rate if GAMI is to be believed this is all academic because the final set of approvals should come out before G100UL is practically available anyway.
I think a big factor here is the sentiment of people who live near small airports. The noise is already an issue. At least now there won’t be lead raining down on the neighborhood, so maybe less petitions to close the airport.
As well, every time I test the fuel on a Cessna it inevitably sprays everywhere so there’s that worry too.
If you look at Chandler Az's small airport, you'll see it is now in the middle of a dense sprawl of suburbs, who no doubt have no idea leaded fuel it burnt over their heads day and night. Minimum house price in the areas wasn't less that $500k last time I looked, and those were few. Intel is just to the west. https://www.google.com/maps/place/Chandler+Municipal+Airport...
I’m somewhat surprised, based on state lead disclosure laws, that this too isn’t required to be disclosed to buyers of properties within proximity to airports that provide 100LL from their FBOs. It’s worse than lead paint (typically stable if not disturbed) in that it’s in the air and on the soil.
You might expect the noise, but you’d have to be versed in general aviation to know you’re being exposed to lead from combustion pollution.
And importantly in this context: The magic word is "piston-driven". Lots of aircraft you see look to a lay person like they don't have a jet engine, because there are propellers just like on a piston-engined plane. But a https://en.wikipedia.org/wiki/Turboprop is a very efficient jet engine that just happens to be driving a propeller and so they're running on JetA fuel which never had lead in it. (There are still lots of reasons not to exhaust that into the sky either, but at least it doesn't have lead in it)
It may also be used for some very old cars. "This should be in a museum" (and maybe is) level cars may have been impossible to adapt to unleaded gasoline. So, one option is you just don't run them - after all these are very old cars they're both unsafe and inefficient by modern standards with few creature comforts. But if you're exhibiting cars in working condition you've got two practical options:
1. Add a lead additive, you don't need very much, and since this isn't exactly your daily driver it's not so terribly inconvenient, you can buy this over the Internet. You just pour a measured ammount in to the tank each time you re-fuel. I don't think this is illegal in the US, but I don't know if it's common. At population scale it isn't a big nuisance.
2. Choose a substitute additive, which is likewise added to fuel. There are several, but whether they work for you is a question and of course the manufacturers are not interested in insuring your potentially unique 100+ year old car for damage from their cheap additive product. If you suffer mechanical problems that's your problem.
There's a lot more piston plane flight than there are people still driving a classic era car on any particular day.
It would make sense that lead aerosolized in the air has more access to human biology than lead in undisturbed paint.
Degraded lead paint consumed by unknowing children would probably deliver high concentrations, but a lot of that will travel unabsorbed through the intestinal track. Aerosolized lead paint would be unavoidable with a higher proportion passing into the bloodstream through the lungs, and therefore on a more express route northwards where it can pass between the blood-brain barrier.
Concentration could make a huge difference, though. Paint is in enclosed spaces without ventilation, often. Aeroplanes are not in the context of suburb effects.
Aviation 100LL is 0.56g of lead per gallon. Small Cessna 172 burn ~10 gal/hr in flight.
Presumably taxiing and take off burn a few gallons, so 1gm of lead dispersed over a pretty wide area. So at any given point in the area your overall exposure is low.
Thanks for those numbers. As a contrast, the lead content in lead-based paint can be up to 50% by weight for really old paint, down to 0.5% before lead was banned. A single house full of old lead paint can easily contain many kg of lead.
It's true that as long as that paint is in good condition and isn't disturbed, it's not harmful. However, paint deteriorates and chips, is disturbed when remodeled, etc. One tiny paint chip of old paint can easily have more lead than that Cessna dispersed around the airport, and it's concentrated in a single article.
There's a crap ton of lead paint still around and sooner or later it's going to be mobilized. It's a fiction to think that an EPA-approved hazmat team will be dispatched whenever one of these old houses are torn down or remodeled. I'm much more worried about paint than a little avgas spread out evenly across the landscape.
How many planes land & take off every day though? Over the course of a decade, sitting in small quantities on literally ever outdoor surface...
Comparing it to lead paint is the wrong comparison. Take a look at what lead in the water supply, even at small concentration, can do to people. That's more comparable to air dispersal.
If lead from avgas was an acute problem, literally everyone who lives near GA airports would have high lead levels. I've not heard of such a situation, though.
I think that evidence points to plenty of cases of lead poisoning from lead paint and, yes, lead in water. I have yet to hear of anyone getting lead poisoning from living near a GA airport.
Do note that lead paint also leads to contamination of surfaces and soils, as deteriorating paint turns into dust.
I don't think water contamination is similar to air dispersal at all. People consume a certain amount of water out of the tap every day, and whatever is in the water ends up in the body. There is a much less clear absorption chain from lead emitted into the air to the body.
Edit: I did the math based on the numbers above: Within 1 mile of an airport (typical pattern size) with 100 take-offs per day, each using 1 gallon of avgas so emitting 1g of lead will, over a decade, deposit ~50ug of lead per m^2.
If we say a yard is 100m^2, that's 5mg of lead. That's the equivalent lead content of < 1g of lead-based paint.
I'm not disputing that if you live in a new house, far away from a highway, but near a GA airport, avgas might be the major contribution to your lead exposure. But compared to the lead exposure risk from houses still containing lead paint, it seems completely insignificant.
Yes, we live just a couple of miles from the airport in downtown Renton, WA (Seattle suburb). Small planes burning leaded fuel takeoff and land over the town and over Lake Washington. We are not in the flight path, but it’s very concerning for everyone who is and for all the fish in that lake.
I could not find any data on the actual levels, but there is data available on the effect on children.
By the late 1970s "88% of children had a level exceeding 10 μg/dl" [1] while current data from near the Reid-Hillview Airport shows that there is no particularly noticable effect [2] with just 1.7% of children having a blood level above 4.7 ug/dl. On average around 2% of children in the US regardless of location have a blood lead level around that number.
Guaranteed kids will have levels medically too high is a policy problem. Immediately downwind of the interstate in the 70s was apparently a very bad place for kids to be, and policy fixed that (more or less).
Almost no kids will have high levels now, and those few with higher levels experimentally are from uncountable random sources rather than the point source airport, is not a useful aviation policy problem.
> I think a big factor here is the sentiment of people who live near small airports.
(disclaimer: am a pilot, so biased) They don't really build small airports anymore, so the vast, vast majority of people who live near small airports chose to move there knowing in advance that the airport was there. Then they complain about the noise and pollution. There's a doctrine in Real Estate law called "Coming to the Nuisance" [1] which exists as a defense to these complaints. People who moved there knew what they were getting themselves into and assumed the risk of harm.
I don't like that our airplanes spew lead into the environment, and am really really happy that an actual viable unleaded solution is finally on the horizon, but I also disagree with moving in next to an airport and then immediately complaining about it.
From Wikipedia:
The Living With Your Plane Association estimates that there are at least 426 residential airparks in the United States. Florida is estimated to have 52 airparks, followed by Washington with 50, California with 28, and Oregon with 23.
How many people here do you think live near under the flight path of GA airports?
How many people here do you think see the "LL" in 100LL and see an easy source of internet virtue points?
Hatred for lead pollution in any capacity is just one of those community tropes here. The people who care are probably outnumbered 10:1 by people who just wanna be seen looking like they care. It's the same level of caring as a retweet or signing a change.org petition. Welcome to bike shedding 101.
You should honestly ask yourself why this is not a popular comment.
If you start by assuming everyone else is arguing in bad faith ("people who just wanna be seen looking like they care"), then it's easy to dismiss any criticism, and it'll be hard for you to prove yourself wrong.
If you never try to know when you're wrong, you could end up stuck with wrong beliefs for the rest of your life.
I have no stake in your life, but I'd recommend against that.
I know why it's a not a popular comment. Because everyone who cares enough to sling shit on the internet but not more than that is annoyed that I pointed out that that's where their line is drawn.
The fact that people think every un-flattering observation about online discourse is assumed to be in bad faith says something. I'm not sure what but it's certainly un-flattering as well.
Unflattering observations are fine, if they're based on solid evidence or at least some sort of logical process of determination. You do neither of those things and just throw around your personal opinion as gospel. It's unnecessary and doesn't add anything of value to the conversation.
There does tend to be a strong overlap with tinkering with code to tinkering with physical things. Woodworking in particular seems very popular amongst my group of software inclined folk.
Woodwork seems like pretty much the perfect retirement hobby too. Not too physical, time > skill > exertion, and enough depth in the topic to last a lifetime.
Honestly: at least in my circle there is an oddly massive cross section of tech workers who have private pilot's licenses. In my relatively small circle (less than 200 people) of close friends/acquaintances, 25% of the tech workers have a private's pilot's license and 0 of the non-tech folks.
Maybe it's truly just my circle but I always found it odd/amusing that such a high percentage had or were going for their pilot's license. Maybe the same personality trait that pushed them to tech pushes them to want to fly themselves. And/or it's just a matter of having more expendable money and free time than the average joe.
Either way I think it's less HN and more the profession.
That was me. Played FS2, F/A-18 Hornet, Falcon 3.0, tons of others. Always wanted to fly. Finally grew up, made some money, and got a lesson. Turns out I'm terrified of small planes. Then I learned they're roughly as dangerous as motorcycles for a given distance traveled (about 10x the risk of an auto) and gave up the dream for good.
Ha. I did exactly the same thing. Took a lesson, was terrified the entire time. I like flying in the bigger stuff but a cessna seems like somebody has thrown a volkswagen beetle into the air. Every time that thing dropped a metre due to turbulence i was glad i went to the toilet beforehand.
Not a bad comparison actually. Between the airframe design era, air-cooling etc it's pretty apt.
Fwiw I think the overlap is also because the tech thing. Flying airplanes is a pretty technical hobby so it makes sense it appeals to people like us tech workers
I think flying is especially attractive to people in tech because it is cognitively demanding (flight planning, comms, instrument work) but also requires a lot of physical coordination and prediction (landing, stall recovery, maneuvers) that working in front of a computer doesn’t help you develop.
It also requires you to develop a certain level of personal responsibility and good decision making to fly safely. This positively impacts the management of a team/company.
Depends - here in Europe you can jojn the local "aeroclub", pay a reasonable yearly fee, perform various work alignments from the club (airport and aircraft maintenance, manning the advisory radio service on the tower, etc.) and then you can fly the clubs gliders at first come first served basis (after appropriate training of course).
This way even university students can fly (gliders) without being rich & quite a few of my friends did.
Also, not really a problem with leaded fuel in most gliders. ;-)
(The towing aircraft or the winch might be a different matter.)
Yeah flying clubs and/or experimental aircraft are the way to go, cost wise. There are some complications for learning to fly that way, but it can be much cheaper. We estimate the hourly cost of operation for our Sonex (https://www.sonexaircraft.com/) is $35/h.
G1000 is overkill for PPL, though. Admittedly I did mine in 2011 so it's been awhile, but I was paying $145 an hour then plus $60 for the CFI, so around $200 per hour all in.
Considering you can do 10 hours sim time toward the minimums, I don't think $10k is impossible? But ancillary stuff will probably get you to $11k or $12k admittedly. In my case I did the American Flyers weekend ground school for the written test and they gave you a few hours of sim time included with the course cost.
No doubt safer for IFR purposes. I have a little time in a G1000 but a lot more with aftermarket Aspen panels, I put them in my own airplane back in 2014.
I had no problem taking off into a fog with 3D terrain in the panel. On old mechanical gauges with nothing but a beep telling me about the mountain? .... not so much....
Then again, I also live in North-Central Texas. Every black spot on the ground that you can't see at night is a cow pasture devoid of trees, land in whichever one you like with your dead engine and your odds are pretty good.
i'm hopeful that the interest here is indicative of a broader politically-relevant interest. personally, i have no great interest in general aviation and am not even a very good environmentalist, but i'm enthusiastic about the advancements here because it seems like the sort of easy wins we should be pushing for, where a lot of the hard work has already been done.
i'm basically just here as a bandwagon fan so i can celebrate when "we" win this one. the same way i cheer when my local hockey team makes the playoffs. and i suspect that a lot of us are following this story for similar reasons.
I visited GAMI’s Ada, OK facility in early 2014 and got a demo of their fuel that was already flying (in experimental category). A lot of the hard work was done almost a decade ago. It’s frustrating to me how slow the approval process has gone, but it’s got to be 10x as frustrating to GAMI.
The entire topic is a virtue signalers paradise. Insert unscientific outrage in the vending machine, get free karma. No need to know anything about the specific topic or the environment or chemistry or aviation or statistics to get that sweet karma.
> I'm curious to know if this is indicative of a broader (politically-relevant?) interest in getting lead out of GA, or just the sort of specialist topic that tends to interest HNers
I have no interest in or connection to general aviation (beyond agreeing with Mojo Nixon on the topic of small private planes) but as a person who breathes air straight out of the atmosphere I have a strong interest in lead.
Can the availability of this fuel be scaled readily, or will most people be stuck with leaded fuel still? Can companies other than GAMI make this fuel?
GAMI claims the licensing for this will be relatively open, and Avfuel (very strong presence in GA fuel) claims they'll be pushing this out, so at least in theory it could see relatively rapid adoption.
George Braly (principal engineer at GAMI) has also claimed that all ingredients are readily available to and capable of being processed at any refinery currently making 100LL.
I'm excited about this push. One interesting note is how this entire project has been 'in flight' for 30+ years almost cancelled with PAFI and then with then with recent pressure to close airports (namely KRHV) with leaded fuel as the lighting rod the FAA has now accelerated to “progress at the speed of light.”
"He added that the accelerated commitment reflects new urgency arising from the FAA’s awareness that some local governments are taking action to ban leaded avgas from being used at airports in their jurisdictions.
Local governments threats driving innovation at the federal level :P
> recent pressure to close airports (namely KRHV) with leaded fuel
It's always been a real estate issue with KRHV.
The nearby busy highways emit vastly more emissions than trainers, likely including lead.
What city councils refuse to acknowledge is that once you close a city airport, you can never build another one. This is especially an issue in an earthquake zone.
There's likely trace elements in fuel. In the case of that area, the Capitol Expressway is a very busy highway system.
If RHV air quality is monitored, then so should some locations around the highway. In fact, there's enough cars surrounding the airport that it would influence air quality measurements inside the airport perimeter.
I mentioned the quake issue because I have seen documentation that RHV is part of the emergency response plan for transporting relief cargo.
> What city councils refuse to acknowledge is that once you close a city airport, you can never build another one.
Is that a bad thing? A substantial fraction of the population uses the local highway on a daily basis, whereas very very few people use small local airports with any similar frequency
Have there been any publicized studies done on the reliability of aircraft engines, with and without lead? I’m guessing this is what made the transition take so long, but I can’t seem to find any references.
It’s a rather complex topic with all sorts of factors including economics of a small market and FAA red tape. Av web has a great multi part on failure modes of engines and why new engines often don’t succeed
Another problem is, IIRC, that many replacements for leaded fuels have evaporation & performance issues at lower pressures that don't matter in a car but can be critical in airplane (it's even worse with ethanol additives, IIRC).
I honestly think there should be civil consequences for the FAA slow-rolling the sunsetting of leaded avgas. Red tape is causing very real harm to vast numbers of people.
As with many problems with hard-to-see externalities, I think the FAA can't win here. If a plane falls out of the sky because of a fast-tracked approval, or people go out of business because of a fast-tracked ban, then the FAA is the bad guy. The number of people with the ability to assess the impact of atmospheric lead is much smaller.
In general: no. In aviation you don't do "this should probably work so let's do it". You follow approved guidelines and procedures and only approved guidelines and procedures. When there are a hundred separate things that can go wrong and kill you, you don't stray outside the lines.
Avgas is the only remaining lead-containing transportation fuel. Lead in avgas prevents damaging engine knock, or detonation, that can result in a sudden engine failure.
If engine knock can knock you out of the sky, it's probably not something you want to just take a chance with.
To somewhat expand on the other answers: The only reason there are cars that "require 93 octane but can run 87 with lower power" is that they have knock sensors and ECUs that can limit ignition timing to avoid knock. This is a sophisticated system and nothing like it is available in any aviation engine, being designs from the 50s (except maybe some new experimental engines.)
The effect of running too low octane fuel in an aviation engine is not "slighly less power", but likely detonation and catastrophic engine failure.
And that's why it's a violation of FAA regs to run aircraft on non-approved fuels.
Just because something is old doesn't mean it should get a free pass on continuing to use leaded fuel though... there must be other reasons why leaded is still used besides simple knock sensors and ignition timing.
Exhaust valve seats. If you don't use appropriately hardened seats, you need lead to help cushion the wear between the exhaust valves and their seats in the head.
If your perfectly reasonable next question is, why aren't standard aircraft engines just built with the appropriate seats, well, then... The answer is low market volume coupled with high regulatory hurdles. There aren't any villains here, just written-in-blood safety regs coupled with a small enough market that there is a lot less money available to fight inertia.
Exactly. Flying for sport is expensive as it is today because safety has to be a priority (as it should). Add a requirement for new engines or major overhauls on old planes and the cost will spiral out of control.
Besides, leaded fuel was a problem when literally every single car on the street was burning it. The total volume of fuel consumed by aviation piston engines is a joke compared to that.
In the case of Lycomings at least these valve guides have been hardened on cylinders produced since 1998, without having to certify a new type. On the Lycoming engines approved for 94UL I'm not aware of a restriction that these new guides must be installed for unleaded use.
Also, aviation engines are in general pushed far closer to their operational limits than a regular car engine. The latter might see full throttle and need to generate its rated power for a few percent of its life. Failures are not too dangerous. The former needs to generate rated power for a far larger fraction, and is also held to much higher reliability standards. Hence the requirement for high octane fuel and massive displacements relative to power output.
The difference in operational regime is true, although it's my impression that automobile engines are pushed through some very severe tests as part of their development. For example, this movie, https://youtu.be/GNPB3RtHN2M, claims that KIA tests their engines for 300 straight hours at full throttle.
As for reliability, I'm not convinced. In practical terms, I think automobile engines are far more reliable than aircraft engines. When was the last time your automobile engine broke an exhaust valve, cracked a cylinder head, or had a magneto come apart?
When was the last time your automobile engine broke an exhaust valve, cracked a cylinder head, or had a magneto come apart?
Exactly. An automobile engine is subjected to far less stresses in normal operation. 300h at full load is considered an extreme torture test for one, while a typical aircraft engine is meant to run for over 1000h between overhaul ( https://en.wikipedia.org/wiki/Time_between_overhauls ) and spends a significant amount of that time at full load --- that's normal operating conditions.
The Pilot Operating Handbook (POH) contains numerous tables that pilots use to calculate what will be safe operating conditions for an aircraft. These include how much runway will be required at specific temperatures/elevations to clear obstacles. Those numbers were based on a 100 octane fuel so if the fuel is changed, those values must be determined once again and I believe that is largely done with flight testing. To do that on the entire fleet would be prohibitive.
Without these small planes the misery you experience flying commercial would increased greatly due to the lack of pilots. It's pretty bad as it is.
From what I can google it looks like they ban the sale of leaded avgas at those airports. If you run out of gas at one of those airports I imagine you're purchasing it elsewhere and one way or another arranging for it to be delivered to you at the airport at your expense + hassle.
Now can they up the weight limit for electric ultralights (300 lbs so it's the same as a full tank of gas) or not include the batteries towards the limit?
Why should they discount battery weight from the limit given that you do not lose that weight and thus it counts for all the reason weight limits are involved?
That's not actually that's not true. ICE powered ultralights are weighed without fuel. The fuel limit is 5 gallons. So while the empty weight (in the regulations) is 254 lbs, the expected weight ready to fly is 300 lbs with fuel. Since the batteries don't have empty/full weights, it makes sense that they would increase the limit for electric ultralights to 300 lbs. This does not include weight added for safety devices in the event of catastrophic failure (eg ballistic parachute).
Also the main reason for weight limits (including fuel limit) is to limit potential damage in the event of a crash. This is through a limit on kinetic impact (in addition to weight limit there is a speed limit) and hazardous material (the gasoline).
So if we eliminate the highly flammable gas, then it's possible the battery weight doesn't really matter because a 254 lbs airframe will be physically limited in the weight of batteries that it can support.
GAMI is a really neat company. This fuel additive is only one project; they're also famous for selling tuned fuel injectors to improve engine performance. https://gami.com/
It's 2021. There is no excuse to be using leaded fuel, just as there was none 10 and 20 years ago. If they don't want to implement reforms, the obvious consequence needs to be close down any operation still using leaded fuel immediately. You had plenty of time.
Leaded fuel is an obvious externality. As with all of those, there is no pressure on the ones causing the immediate harm to stop. Government action is required.
It is very strange to see this downvoted. It is very inexcusable that after removing lead from virtually every other source due to its intense long term damage, we let people who fly thru the air spew it out in not-insignificant concentrations from the sky!! For such a heavy particle, I can’t imagine a more efficient strategy to distribute it widely than exactly that.
It is not good to see the cognitive dissonance needed to downvote someone calling that out just because you like aviation on Hacker News. Maybe on an aviation forum I’d understand but here?
The problem is that there's no unleaded fuel that works as full replacement for the low-lead AVGAS, to the point that there are airports where using MOGAS could be considered deliberately inviting disaster. As far as I know, unleaded avgas is quite hot topic in aviation fuel research, but when optimizing for "planes not falling from the air" speed of change can be sometimes slow.
Personally, I can't wait for when we get unleaded replacements for all leaded fuels and can just ban leaded.
That’s only a problem because of the extremely old engine designs which we still use because of the expensive certification process for existing aircraft and new engine designs. We can design much better engines in just about every metric… and we do, just not for relatively cheap and certified GA aircraft.
We actually do have 100LL alternatives and have had them but the missing piece has largely been certification of those fuels or even just carrying mogas for planes that are able to burn it.
It’s been decades at this point. If we can’t find unleaded fuels that work safely for these engine designs, the correct thing to do at this point is to ban the engines.
Then you quite literally kill general aviation, and a lot of smaller scale commercial aviation, because there are no other engines approved for the airframes.
If that's your goal, fine, but don't pretend it's anything else.
what? people with private planes are the ones running leaded currently. people who aren't very wealthy are flying on commercial planes that haven't used leaded gas for decades.
Wealthy individuals’ airplanes are already burning Jet-A in turbine engines.
Who’s piloting the airliners that the not very wealthy are flying on? Working pilots.
In what type of airplane did they train? Piston engine aircraft.
Now that they need to have 1500 hours experience before taking the yoke of a commercial airliner in the US, where will they get that time? Overwhelmingly in piston-engine aircraft. Typically as a flight instructor, which will go to near zero if you kill the ability of practical intermediate distance travel to be done by high-compression and/or turbocharged light aircraft.
(Alaska and Caribbean islands also has a lot of very much not rich people flying around in or getting necessary supplies delivered by 100 octane needing airplanes.)
Commercial operations using 100LL dwarf personal plane operations using 100LL. Cape Air burns way more avgas on a Tuesday in July than I burn in a year.
Back to “Very wealthy” individuals running turbines. If I could afford it, I would be too. It’s a better engine solution (almost) all around, except the operating costs are a low single-digit multiple higher and capital costs around 10x, which puts it out of reach of almost every individual. No one should cry for me here, but there’s a huge subset of 100LL-based operations that you probably approve of or judge essential and want to continue.
Sounds like the approval process is the problem. Banning lead shouldn't "kill general aviation". We'd still have GA even if leaded fuel had never been invented in the first place.
Continued use of leaded avgas is unacceptable, and frankly we've known that it's unacceptable for decades. It's surprising that only now are jurisdictions that contain airports where it's used realizing that they have the power to solve the problem on a local scale by banning those airports from operating, but it's not surprising or unreasonable that they're choosing to do so now that they've realized the problem exists.
If a plane can't be safely flown without leaded avgas, that just means it can't be safely flown. The foot-dragging on this topic is unbelievably shameful on the part of everyone involved, but particularly the FAA. If this kills general aviation, so be it, I'm sure it will light a fire under a lot of asses to get some new airframes and engines certified. If a couple 10s of people die in airplane crashes before all of the kinks are ironed out, so be that as well. That's a trivial amount of harm compared to the harm of airdropping lead on children, and unlike the victims of leaded avgas, everyone who gets in a personal aircraft voluntarily accepts the risks.
In general, local owners of airports can shut down the airport once they’ve satisfied any agreements relating to funding they’ve taken for airport improvements (often paid 90% by an FAA agreement in exchange to operate on a FAND [fair and non-discriminatory] basis for a few decades).
Comply with those terms and keep the airport working using only local funds for that length of time and close it at the end if you want.
There’s no need to shut down the airport entirely. A ban on the sale or overland transport of leaded avgas would be sufficient. Some jurisdictions are threatening this, and the FAA hasn’t made any serious effort to even pretend that it has the authority to prevent it.
Yes, but only after this issue has been known about for decades, and only because some jurisdictions containing airports are threatening to preempt the FAA and ban the sale of leaded avgas outright.
Yes, everything you say is exactly why government action on this would've been appropriate as suggested by the comment I originally defended.
Thousands of people and organizations across aviation benefit in terms of retaining the ability to fly more cheaply. This is true across existing infrastructure, vehicles, engines, manufacturing, certification, etc.. Accordingly, it is clear that the industry will not change; "an object at rest"...
Instead, because of government inaction on the topic, presumably because of aviation's ties with the military and wealthy folk in general, these thousands of people and organizations retain their benefit at the expense of everyone else. They simply spray poison from the air in a manner which seems, again, one of the most efficient ways to contaminate the environment with this poison. It is clearly not beneficial to anyone except those in the ingroup, which is a vast minority. Why would government action to force this stale industry be inappropriate?
Except it's not that there was government inaction. The very article discussed is FAA making the rounds to cover 70% of powerplants used in general aviation, which isn't just joyriding for wealthy people (and military doesn't give a damn, cause they aren't bound by those limits). The actually wealthy people don't care either, because they can afford turbine engines.
In fact despite somewhat higher price at source for G100UL, there's considerable possibility it will lead to cheaper operation thanks to lower maintenance impact compared with leaded fuel, and GAMI is hopeful about it being rated for full power usage even in place of other, even rarer fuels.
There are various problems with just banning GA, no matter how wealthy suburbs would love to do it. From impacting training pipeline, to all kinds of operations that would be involved that you might not think of (whether it's connecting random communities in Alaska, where some cargo is still flown on WW2-vintage DC3s, to medical transports).
> Except it's not that there was government inaction. The very article discussed is FAA making the rounds to cover 70% of powerplants
... In the year 2021, over 50 years after the automotive industry had already invented engines which could run on unleaded fuels. I'm sorry, but this is an almost farcical point, "it's not government inaction it's just 50 years late!"
> In fact despite somewhat higher price at source for G100UL, there's considerable possibility it will lead to cheaper operation thanks to lower maintenance impact compared with leaded fue
Great, so the government could've forced industry's hand 50 years ago and the industry would probably be running for cheaper right now. This doubly shows the importance of government action on the topic - it would've been better for literally everyone in and out of aviation if the switch had been mandated. How about that for a story of inefficient markets?
> There are various problems with just banning GA
I work in aerospace, do not condescend to me on the topic. The point is that 50 years of inaction results in cases where, like in East San Jose, "2.5 percent of children under 6 years old who were tested had detectable levels of lead in their blood"[0]. "GA" clearly could and should have dealt with the issue of poisoning the masses for their own ends, and the fact you would defend them and the government for not stepping in in such circumstances makes you a fool.
> after removing lead from virtually every other source
Not even remotely the case.
Removed from new paint sales, with measurable positive results in the population.
Removed from motorgas for car use, with measurable positive results in the population.
That's it. The other remaining uses, of which there are many, seem in infinite studies to show no measurable effect on the population, so its going to be difficult to remove them then show a measurable improvement.
The money is better spent elsewhere, somewhere with more bang for the buck than measurably provably zero.
It's pretty funny to argue that "government action is required" when pretty much the reason that aviation piston engines largely are still based on designs from the 50s is precisely that the government will not let you use anything else.
In order to sell an assembled aircraft, with very few exceptions, it needs to be certified by the FAA, and convincing them to allow you to sell a new engine is sufficiently complicated and expensive that the very small airplane market does not make it worth it. (The total number of piston aircraft sold in 2020 was 1300. The best-selling aircraft, the Cessna 172, sold in the 200s.)
The only development of new piston aircraft engines are for experimental aircraft, where no FAA approval is needed. In that market you find electronically controlled engines with the same features as automobile engines, and not requiring leaded gas. But those airplanes cannot be sold except as kits.
Even engines that need 100-octane gas would benefit from unleaded fuel, because the lead deposits are very bad, forces the use of inferior, non-synthetic oil, makes valves stick, fouls spark plugs, and is generally nasty. Believe me, no one wants to use leaded gas if they can avoid it.
The FAA and the EPA have conflicting missions here. Unfortunately the public is more scared off death by air crash than death by pollution, even though air pollution is a bigger killer. This means if there’s a conflict, the FAA is probably going to win over the EPA.
The EPA should ban unleaded fuel immediately regardless. Make the FDA choose between lobbying to have the ban overturned (against public opinion I would hope) or unblocking the development of better engines.
And as a result most small aircraft engines are naturally aspirated and have carburetors, even though turbo/super charging and fuel injection make even more sense in airplanes than they do in cars because of constant ambient pressure changes.
It's hard to find a car with a carburetor these days; fuel injection is ubiquitous and cheap. Not so in airplanes. You can actually find fuel injected and/or turbo airplane engines but they're priced as if they're made of gold, so they're strictly for rich pilots.
GA aircraft electronics are quite modern. But GA engines use 70-year-old technology. It's ridiculous.
The FAA is the hindrance, not anyone flying or selling the airplanes.
If you want to talk to the FAA about an engineering approval you're looking at a 6 month lead time before you get an appointment for a meeting. If you are looking to compete with someone who has a similar approval for a similar thing, you can expect them to cancel the first meeting or two inexplicably and stretch it out to a year, maybe two, because you haven't paid the FAA's brother in law engineering firm to keep competitors out, the other guy you're trying to compete with paid them. All the while you pay your fixed costs, salaries, etc out of pocket.
Whatever you bring to the meeting won't be good enough, they'll send you back to change something at least once, even if you copy and paste someone else who has done an identical thing for a marginally different application.
If you run the gauntlet you'll get an approval to make your thing for ONE make/model of airplane. Want to put it on a Piper instead of a Cessna with the exact same engine? Go back to square one, repeat.
This all became the norm when? IP was extended to aircraft modifications, during the Clinton admin when the internet took off.
So you see, it isn't aviation that slowed aviation to an innovative standstill. The tech world's ideas of IP ideas did that. Prior to the advent of IP in aircraft paperwork, it was pretty common to be able to come up with an idea, sketch it out by hand, fly over to the local FAA office, demo it to an FAA engineer on the ramp, and have him help you go forward with it to get it approved. IP took away the motivation to innovate and created a motivation to fight back and forth with lawyers instead. You know... like tech corporations do with software patents.
> If you are looking to compete with someone who has a similar approval for a similar thing, you can expect them to cancel the first meeting or two inexplicably and stretch it out to a year, maybe two, because you haven't paid the FAA's brother in law engineering firm to keep competitors out, the other guy you're trying to compete with paid them.
This is a shocking level of corruption you're describing.
I had an airplane until 2018 that optionally shipped with a rather unique air conditioning system. Rather than the compressor being engine powered like most other cars and small piston engined airplanes, there was a second alternator on the engine used to drive an electric motor which in turn powered the compressor.
This was all done mostly for weight distribution. The design of the airplane was somewhat nose heavy because the factory added a turbo system with a cast-iron manifold. So they moved the A/C system to the tail with the electric motor for power, and put it all on a shelf behind the baggage compartment in the back.
Since the airplane was built in the mid 1990s the factory is out of business, they went bankrupt in the early 2000s. The supplier of the electric A/C system components is still in business but they only deal with helicopters now, they don't have anyone left at the company who knows about the airplane units they used to make. Only about 50 of the make/model of airplane with the turbocharger option were built, so there's no motivation to keep them going for anyone else who might make parts. The market is too small.
I found an aftermarket A/C system very similar to the one the factory built in the 1990s and with the maker of that system went to the FAA to get approval for it. The aftermarket system is actually simpler electrically. Rather than two alternators with a relay system it uses one of the largest alternators you can buy, on all of the airplane's existing electrical circuit. You just have to beef up the battery cables and the circuit breaker on the alternator to handle the extra amperage. It took us 6 months and ultimately a suggestion that we have a particular engineering firm look at our plans. They were basically requiring us to re-approve the entire system, even though the system is approved in other airplanes with identical engines. All we needed approval for was a larger alternator (minimal change to weight/balance) and the repurposing of a material made by Boeing for the rear shelf (we told them we intended to use the floorboard material that Boeing puts in 737s, it's a fiberglass sheet reinforced internally with an aluminum honeycomb mesh, that can bear about twice the weight per square inch that we needed to put on it).
They made us have that engineering firm submit stress and load test data on the shelf material that Boeing already uses for the 737.
The only reason we jumped through all the hoops was the fact that the aftermarket A/C system's installer has a relative that was a 30 year Embraer engineer. He would just help us do the drawings and calculus for free as long as his son's maintenance shop was going to get the installation job. Absent that, the ~$25,000 job would've been a $50,000 job, which just isn't worth it for an airplane that's worth less than $175,000 to start with.
When we were willing to turn over the copyright of the plans to the engineering firm we were suggested to hire to "review" the data for the requested approval, including them copying and pasting Boeing's stress and load test data for the floor material Boeing already uses, suddenly the floodgates opened and everyone was happy. The paper was all signed and we got permission to put a marginally different air conditioner in one make and model of airplane (of which only 50 exist in the wild).
From initial sales call to cool air in my airplane: about 8 months.
The time to install it for two guys was about a week of shop time. After all, they put it in dozens of other makes/models and it's all the same stuff.
----------
If you want another example, you can go down the rabbit hole of a local (to me) company called Navworx, which was aggressively pursued and ultimately closed by the FAA, because the FAA changed the ADS-B spec rendering their ADS-B receiver worthless, after the spec had been in the field for about 3 or 4 years.
There are some interesting Diesel engines in aviation now like the Diamond DA42 and 62. They run on Jet A and are basically Diesel engines. Jet A and diesel are similar.
I'm sure many people who don't fly aircraft are not aware of the pre-flight check procedure part of which is to check the fuel.
There is a small graduated cylinder with a spike at the top it is pushed into a valve under the wing to get some fuel from that tank. You look to see if there is any water floating in the gas. After you check it you toss the leaded gas on the tarmac. Then you do the same for the other wing tank.
Airports especially small airports with piston powdered light aircraft using leaded avgas must be soaked in 70 years lead.
I’m a pilot and use a GATS jar that lets me separate out water and toss the fuel back in the tank. Tossing fuel on the ramp is frowned upon at some FBOs.
Same, it amazes me how many people around my airport don't use these. In my mind they enhance safety too because I can sump more gas and sump all the tanks at once, so if one tank is all water I'd know.
On the other hand the FBO could accidentally put in jet fuel and not realize it.. and it could be done in such a proportion that your eyes won't notice it in a gats jar.. the best way to test it is either to dip a paper towel or toss it on the ground
The screen on the GATS jar is for testing for Jet-A contamination. Gas evaporates cleanly off the screen. Jet leaves a film in a random pattern as it evaporates.
Pretty common when there's a fog and you get condensate. The tank on a small airplane isn't gonna be sealed air-tight, it's vented to the outside air so a little condensate is pretty normal.
Water is heavier than the gas, so it sinks to the bottom where the drain fitting is.
It very much depends on the airplane. Mine has 7 sump locations. A C172S has 13. If it overall adds up to 7mL, I think you’re not sampling enough. 7mL per sump location might be barely enough.
Ah we were taught only to use the bottom two on the wing tanks. This is probably why. Of course they do this for every student flight where it's really only necessary before the first flight of the day. So I think this plays into it (not wanting to waste too much fuel).
Also the 7ml is not my figure. The "shotglass" is usally more than half full. I agree 7ml is not a lot.
No, but nearly all of the cost associated with aircraft operations is either fuel or maintenance. On a light aircraft like a C-172, the only moving parts are the control surfaces, a couple gyros for the avionics, and the engine. Remove the engine and 99.9% of the fuel costs and 95% maintenance costs (avionics aren't cheap, but modern ones are more reliable) also go.
No we just have to wait until they start approving engines to use synthetic and/or bio-based avgas. Then we can finally have carbon neutral flights in existing aircraft.
Bio-based is a minefield of a few ways to have it reasonably ok'ish (mostly if it's stuff that would otherwise be waste) and countless ways to produce more emissions than before. The latter is usually what happens...
Here in Europe the turbodiesels seem to be more popular as an alternative. But it's still pretty hard to get them approved. And I believe they require a full replacement instead of a rebuild every few years.
I think it's highly preferable because many airports don't really want to be selling avgas anymore, and this will only become more of a problem as it's phased out. There's also a huge price difference.
182 comments
[ 4.2 ms ] story [ 211 ms ] threadIt's interesting (but not unexpected in hindsight) that this new slew of approvals (generally) only impacts engines previously approved for low-octane unleaded fuels (e.g., 94UL). Even smaller engines like the Lycoming IO-360 (except the derated -L2A) aren't approved despite only modest power increases over the O-360.
At any rate if GAMI is to be believed this is all academic because the final set of approvals should come out before G100UL is practically available anyway.
As well, every time I test the fuel on a Cessna it inevitably sprays everywhere so there’s that worry too.
You might expect the noise, but you’d have to be versed in general aviation to know you’re being exposed to lead from combustion pollution.
1. Add a lead additive, you don't need very much, and since this isn't exactly your daily driver it's not so terribly inconvenient, you can buy this over the Internet. You just pour a measured ammount in to the tank each time you re-fuel. I don't think this is illegal in the US, but I don't know if it's common. At population scale it isn't a big nuisance.
2. Choose a substitute additive, which is likewise added to fuel. There are several, but whether they work for you is a question and of course the manufacturers are not interested in insuring your potentially unique 100+ year old car for damage from their cheap additive product. If you suffer mechanical problems that's your problem.
There's a lot more piston plane flight than there are people still driving a classic era car on any particular day.
Degraded lead paint consumed by unknowing children would probably deliver high concentrations, but a lot of that will travel unabsorbed through the intestinal track. Aerosolized lead paint would be unavoidable with a higher proportion passing into the bloodstream through the lungs, and therefore on a more express route northwards where it can pass between the blood-brain barrier.
Presumably taxiing and take off burn a few gallons, so 1gm of lead dispersed over a pretty wide area. So at any given point in the area your overall exposure is low.
It's true that as long as that paint is in good condition and isn't disturbed, it's not harmful. However, paint deteriorates and chips, is disturbed when remodeled, etc. One tiny paint chip of old paint can easily have more lead than that Cessna dispersed around the airport, and it's concentrated in a single article.
There's a crap ton of lead paint still around and sooner or later it's going to be mobilized. It's a fiction to think that an EPA-approved hazmat team will be dispatched whenever one of these old houses are torn down or remodeled. I'm much more worried about paint than a little avgas spread out evenly across the landscape.
Comparing it to lead paint is the wrong comparison. Take a look at what lead in the water supply, even at small concentration, can do to people. That's more comparable to air dispersal.
I think that evidence points to plenty of cases of lead poisoning from lead paint and, yes, lead in water. I have yet to hear of anyone getting lead poisoning from living near a GA airport.
Do note that lead paint also leads to contamination of surfaces and soils, as deteriorating paint turns into dust.
I don't think water contamination is similar to air dispersal at all. People consume a certain amount of water out of the tap every day, and whatever is in the water ends up in the body. There is a much less clear absorption chain from lead emitted into the air to the body.
Edit: I did the math based on the numbers above: Within 1 mile of an airport (typical pattern size) with 100 take-offs per day, each using 1 gallon of avgas so emitting 1g of lead will, over a decade, deposit ~50ug of lead per m^2.
If we say a yard is 100m^2, that's 5mg of lead. That's the equivalent lead content of < 1g of lead-based paint.
I'm not disputing that if you live in a new house, far away from a highway, but near a GA airport, avgas might be the major contribution to your lead exposure. But compared to the lead exposure risk from houses still containing lead paint, it seems completely insignificant.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3230438/
https://www.smgov.net/uploadedFiles/Departments/Airport/News...
I'm (wildly) guessing 0.1% of those lead levels.
By the late 1970s "88% of children had a level exceeding 10 μg/dl" [1] while current data from near the Reid-Hillview Airport shows that there is no particularly noticable effect [2] with just 1.7% of children having a blood level above 4.7 ug/dl. On average around 2% of children in the US regardless of location have a blood lead level around that number.
[1] https://www.jci.org/articles/view/28232 [2] https://sanjosespotlight.com/san-jose-airport-lead-levels-ar...
Guaranteed kids will have levels medically too high is a policy problem. Immediately downwind of the interstate in the 70s was apparently a very bad place for kids to be, and policy fixed that (more or less).
Almost no kids will have high levels now, and those few with higher levels experimentally are from uncountable random sources rather than the point source airport, is not a useful aviation policy problem.
Allowing leaded avgas has always been a policy decision to cater to GA over the health of, among others, children.
Both seem very countable and fixable.
(disclaimer: am a pilot, so biased) They don't really build small airports anymore, so the vast, vast majority of people who live near small airports chose to move there knowing in advance that the airport was there. Then they complain about the noise and pollution. There's a doctrine in Real Estate law called "Coming to the Nuisance" [1] which exists as a defense to these complaints. People who moved there knew what they were getting themselves into and assumed the risk of harm.
I don't like that our airplanes spew lead into the environment, and am really really happy that an actual viable unleaded solution is finally on the horizon, but I also disagree with moving in next to an airport and then immediately complaining about it.
1: https://dictionary.thelaw.com/coming-to-the-nuisance/
https://www.google.com/maps/@44.0473359,-121.2771145,1144m/d...
I know I did when I started looking around on Google Maps when we moved here. Hey, wait, is that...?!
A pilot and homebuilder (of aircraft) myself, it’s basically my dream.
That's the case where I live around Dallas and we have a lot of them.
How many people here do you think see the "LL" in 100LL and see an easy source of internet virtue points?
Hatred for lead pollution in any capacity is just one of those community tropes here. The people who care are probably outnumbered 10:1 by people who just wanna be seen looking like they care. It's the same level of caring as a retweet or signing a change.org petition. Welcome to bike shedding 101.
I don't expect this to be a popular comment.
If you start by assuming everyone else is arguing in bad faith ("people who just wanna be seen looking like they care"), then it's easy to dismiss any criticism, and it'll be hard for you to prove yourself wrong.
If you never try to know when you're wrong, you could end up stuck with wrong beliefs for the rest of your life.
I have no stake in your life, but I'd recommend against that.
The fact that people think every un-flattering observation about online discourse is assumed to be in bad faith says something. I'm not sure what but it's certainly un-flattering as well.
Yeah that bothers me as well. Especially since Tetraethyllead is in the perfect form to be absorbed through the skin.
I started using nitrile gloves during that process but it still gets around with the wind at times.
Would be a cool 3D printing project or even a better drain tube product design that springs flush with the plane so that it can't splurt out.
Edit: After some searching came across this [0] -- will probably be buying that.
[0] https://www.sportys.com/multisumptm-fuel-tester.html
Maybe it's truly just my circle but I always found it odd/amusing that such a high percentage had or were going for their pilot's license. Maybe the same personality trait that pushed them to tech pushes them to want to fly themselves. And/or it's just a matter of having more expendable money and free time than the average joe.
Either way I think it's less HN and more the profession.
(Disclaimer: I don’t have a PFL, but my boss does… and his own Cessna)
Not a bad comparison actually. Between the airframe design era, air-cooling etc it's pretty apt.
Fwiw I think the overlap is also because the tech thing. Flying airplanes is a pretty technical hobby so it makes sense it appeals to people like us tech workers
It also requires you to develop a certain level of personal responsibility and good decision making to fly safely. This positively impacts the management of a team/company.
This way even university students can fly (gliders) without being rich & quite a few of my friends did.
Also, not really a problem with leaded fuel in most gliders. ;-)
(The towing aircraft or the winch might be a different matter.)
You don't have to own an airplane, the above presume renting one ($150 to $200 per hour depending on the particulars).
Cessna 172 with G1000 avionics rental rate is 185/hour wet (with fuel) if you pay for a membership program at the flight school. Otherwise ~200/hour.
For rentals you pay for engine time only. There are usually minimums per day if you wanted to rent a plane for a weekend trip or something like that.
Flying Seattle to Orcas Island is a fun little trip.
Considering you can do 10 hours sim time toward the minimums, I don't think $10k is impossible? But ancillary stuff will probably get you to $11k or $12k admittedly. In my case I did the American Flyers weekend ground school for the written test and they gave you a few hours of sim time included with the course cost.
Our non-G1000 has autopilot and the G1000 doesn't (it's an expensive option) but I still prefer the G1000.
I had no problem taking off into a fog with 3D terrain in the panel. On old mechanical gauges with nothing but a beep telling me about the mountain? .... not so much....
Then again, I also live in North-Central Texas. Every black spot on the ground that you can't see at night is a cow pasture devoid of trees, land in whichever one you like with your dead engine and your odds are pretty good.
i'm basically just here as a bandwagon fan so i can celebrate when "we" win this one. the same way i cheer when my local hockey team makes the playoffs. and i suspect that a lot of us are following this story for similar reasons.
I have no interest in or connection to general aviation (beyond agreeing with Mojo Nixon on the topic of small private planes) but as a person who breathes air straight out of the atmosphere I have a strong interest in lead.
"He added that the accelerated commitment reflects new urgency arising from the FAA’s awareness that some local governments are taking action to ban leaded avgas from being used at airports in their jurisdictions.
Local governments threats driving innovation at the federal level :P
It's always been a real estate issue with KRHV.
The nearby busy highways emit vastly more emissions than trainers, likely including lead.
What city councils refuse to acknowledge is that once you close a city airport, you can never build another one. This is especially an issue in an earthquake zone.
If RHV air quality is monitored, then so should some locations around the highway. In fact, there's enough cars surrounding the airport that it would influence air quality measurements inside the airport perimeter.
I mentioned the quake issue because I have seen documentation that RHV is part of the emergency response plan for transporting relief cargo.
100LL by comparison contains 550mg per gallon by intent.
* Sorry for the crazy mixed units; I didn’t write the regulations.
Is that a bad thing? A substantial fraction of the population uses the local highway on a daily basis, whereas very very few people use small local airports with any similar frequency
- The airport existed before the houses went up
- airports can be used for many functions that benefit society, including EMT and business travel
- houses aren't the only zoning category, or even the most important. We have industrial, retail and other zones which help society overall.
https://youtu.be/mwpzTnLC8BY
https://youtu.be/_k1TQGK3mZI
What happens if a 100LL aircraft lands at such an airport? Do they have to disassemble/tow it, or is there some sort of financial penalty?
And the issue isn't only slightly less power.
Avgas is the only remaining lead-containing transportation fuel. Lead in avgas prevents damaging engine knock, or detonation, that can result in a sudden engine failure.
If engine knock can knock you out of the sky, it's probably not something you want to just take a chance with.
The effect of running too low octane fuel in an aviation engine is not "slighly less power", but likely detonation and catastrophic engine failure.
And that's why it's a violation of FAA regs to run aircraft on non-approved fuels.
If your perfectly reasonable next question is, why aren't standard aircraft engines just built with the appropriate seats, well, then... The answer is low market volume coupled with high regulatory hurdles. There aren't any villains here, just written-in-blood safety regs coupled with a small enough market that there is a lot less money available to fight inertia.
To be clear, this is literally true. Those safety lessons were paid for in blood.
As for reliability, I'm not convinced. In practical terms, I think automobile engines are far more reliable than aircraft engines. When was the last time your automobile engine broke an exhaust valve, cracked a cylinder head, or had a magneto come apart?
Exactly. An automobile engine is subjected to far less stresses in normal operation. 300h at full load is considered an extreme torture test for one, while a typical aircraft engine is meant to run for over 1000h between overhaul ( https://en.wikipedia.org/wiki/Time_between_overhauls ) and spends a significant amount of that time at full load --- that's normal operating conditions.
Also the main reason for weight limits (including fuel limit) is to limit potential damage in the event of a crash. This is through a limit on kinetic impact (in addition to weight limit there is a speed limit) and hazardous material (the gasoline).
So if we eliminate the highly flammable gas, then it's possible the battery weight doesn't really matter because a 254 lbs airframe will be physically limited in the weight of batteries that it can support.
And replace it with a battery that has to burn out because it is impossible to extinguish?
Leaded fuel is an obvious externality. As with all of those, there is no pressure on the ones causing the immediate harm to stop. Government action is required.
It is not good to see the cognitive dissonance needed to downvote someone calling that out just because you like aviation on Hacker News. Maybe on an aviation forum I’d understand but here?
Personally, I can't wait for when we get unleaded replacements for all leaded fuels and can just ban leaded.
We actually do have 100LL alternatives and have had them but the missing piece has largely been certification of those fuels or even just carrying mogas for planes that are able to burn it.
If that's your goal, fine, but don't pretend it's anything else.
Ultimately it's a question of money i.e. how badly people want it.
Who’s piloting the airliners that the not very wealthy are flying on? Working pilots.
In what type of airplane did they train? Piston engine aircraft.
Now that they need to have 1500 hours experience before taking the yoke of a commercial airliner in the US, where will they get that time? Overwhelmingly in piston-engine aircraft. Typically as a flight instructor, which will go to near zero if you kill the ability of practical intermediate distance travel to be done by high-compression and/or turbocharged light aircraft.
(Alaska and Caribbean islands also has a lot of very much not rich people flying around in or getting necessary supplies delivered by 100 octane needing airplanes.)
Commercial operations using 100LL dwarf personal plane operations using 100LL. Cape Air burns way more avgas on a Tuesday in July than I burn in a year.
Back to “Very wealthy” individuals running turbines. If I could afford it, I would be too. It’s a better engine solution (almost) all around, except the operating costs are a low single-digit multiple higher and capital costs around 10x, which puts it out of reach of almost every individual. No one should cry for me here, but there’s a huge subset of 100LL-based operations that you probably approve of or judge essential and want to continue.
If a plane can't be safely flown without leaded avgas, that just means it can't be safely flown. The foot-dragging on this topic is unbelievably shameful on the part of everyone involved, but particularly the FAA. If this kills general aviation, so be it, I'm sure it will light a fire under a lot of asses to get some new airframes and engines certified. If a couple 10s of people die in airplane crashes before all of the kinks are ironed out, so be that as well. That's a trivial amount of harm compared to the harm of airdropping lead on children, and unlike the victims of leaded avgas, everyone who gets in a personal aircraft voluntarily accepts the risks.
Comply with those terms and keep the airport working using only local funds for that length of time and close it at the end if you want.
Thousands of people and organizations across aviation benefit in terms of retaining the ability to fly more cheaply. This is true across existing infrastructure, vehicles, engines, manufacturing, certification, etc.. Accordingly, it is clear that the industry will not change; "an object at rest"...
Instead, because of government inaction on the topic, presumably because of aviation's ties with the military and wealthy folk in general, these thousands of people and organizations retain their benefit at the expense of everyone else. They simply spray poison from the air in a manner which seems, again, one of the most efficient ways to contaminate the environment with this poison. It is clearly not beneficial to anyone except those in the ingroup, which is a vast minority. Why would government action to force this stale industry be inappropriate?
In fact despite somewhat higher price at source for G100UL, there's considerable possibility it will lead to cheaper operation thanks to lower maintenance impact compared with leaded fuel, and GAMI is hopeful about it being rated for full power usage even in place of other, even rarer fuels.
There are various problems with just banning GA, no matter how wealthy suburbs would love to do it. From impacting training pipeline, to all kinds of operations that would be involved that you might not think of (whether it's connecting random communities in Alaska, where some cargo is still flown on WW2-vintage DC3s, to medical transports).
... In the year 2021, over 50 years after the automotive industry had already invented engines which could run on unleaded fuels. I'm sorry, but this is an almost farcical point, "it's not government inaction it's just 50 years late!"
> In fact despite somewhat higher price at source for G100UL, there's considerable possibility it will lead to cheaper operation thanks to lower maintenance impact compared with leaded fue
Great, so the government could've forced industry's hand 50 years ago and the industry would probably be running for cheaper right now. This doubly shows the importance of government action on the topic - it would've been better for literally everyone in and out of aviation if the switch had been mandated. How about that for a story of inefficient markets?
> There are various problems with just banning GA
I work in aerospace, do not condescend to me on the topic. The point is that 50 years of inaction results in cases where, like in East San Jose, "2.5 percent of children under 6 years old who were tested had detectable levels of lead in their blood"[0]. "GA" clearly could and should have dealt with the issue of poisoning the masses for their own ends, and the fact you would defend them and the government for not stepping in in such circumstances makes you a fool.
[0]: https://www.nbcnews.com/business/business-news/leaded-gas-wa...
Not even remotely the case.
Removed from new paint sales, with measurable positive results in the population.
Removed from motorgas for car use, with measurable positive results in the population.
That's it. The other remaining uses, of which there are many, seem in infinite studies to show no measurable effect on the population, so its going to be difficult to remove them then show a measurable improvement.
The money is better spent elsewhere, somewhere with more bang for the buck than measurably provably zero.
In order to sell an assembled aircraft, with very few exceptions, it needs to be certified by the FAA, and convincing them to allow you to sell a new engine is sufficiently complicated and expensive that the very small airplane market does not make it worth it. (The total number of piston aircraft sold in 2020 was 1300. The best-selling aircraft, the Cessna 172, sold in the 200s.)
The only development of new piston aircraft engines are for experimental aircraft, where no FAA approval is needed. In that market you find electronically controlled engines with the same features as automobile engines, and not requiring leaded gas. But those airplanes cannot be sold except as kits.
Even engines that need 100-octane gas would benefit from unleaded fuel, because the lead deposits are very bad, forces the use of inferior, non-synthetic oil, makes valves stick, fouls spark plugs, and is generally nasty. Believe me, no one wants to use leaded gas if they can avoid it.
darn TLAs
It's hard to find a car with a carburetor these days; fuel injection is ubiquitous and cheap. Not so in airplanes. You can actually find fuel injected and/or turbo airplane engines but they're priced as if they're made of gold, so they're strictly for rich pilots.
GA aircraft electronics are quite modern. But GA engines use 70-year-old technology. It's ridiculous.
If you want to talk to the FAA about an engineering approval you're looking at a 6 month lead time before you get an appointment for a meeting. If you are looking to compete with someone who has a similar approval for a similar thing, you can expect them to cancel the first meeting or two inexplicably and stretch it out to a year, maybe two, because you haven't paid the FAA's brother in law engineering firm to keep competitors out, the other guy you're trying to compete with paid them. All the while you pay your fixed costs, salaries, etc out of pocket.
Whatever you bring to the meeting won't be good enough, they'll send you back to change something at least once, even if you copy and paste someone else who has done an identical thing for a marginally different application.
If you run the gauntlet you'll get an approval to make your thing for ONE make/model of airplane. Want to put it on a Piper instead of a Cessna with the exact same engine? Go back to square one, repeat.
This all became the norm when? IP was extended to aircraft modifications, during the Clinton admin when the internet took off.
So you see, it isn't aviation that slowed aviation to an innovative standstill. The tech world's ideas of IP ideas did that. Prior to the advent of IP in aircraft paperwork, it was pretty common to be able to come up with an idea, sketch it out by hand, fly over to the local FAA office, demo it to an FAA engineer on the ramp, and have him help you go forward with it to get it approved. IP took away the motivation to innovate and created a motivation to fight back and forth with lawyers instead. You know... like tech corporations do with software patents.
This is a shocking level of corruption you're describing.
I had an airplane until 2018 that optionally shipped with a rather unique air conditioning system. Rather than the compressor being engine powered like most other cars and small piston engined airplanes, there was a second alternator on the engine used to drive an electric motor which in turn powered the compressor.
This was all done mostly for weight distribution. The design of the airplane was somewhat nose heavy because the factory added a turbo system with a cast-iron manifold. So they moved the A/C system to the tail with the electric motor for power, and put it all on a shelf behind the baggage compartment in the back.
Since the airplane was built in the mid 1990s the factory is out of business, they went bankrupt in the early 2000s. The supplier of the electric A/C system components is still in business but they only deal with helicopters now, they don't have anyone left at the company who knows about the airplane units they used to make. Only about 50 of the make/model of airplane with the turbocharger option were built, so there's no motivation to keep them going for anyone else who might make parts. The market is too small.
I found an aftermarket A/C system very similar to the one the factory built in the 1990s and with the maker of that system went to the FAA to get approval for it. The aftermarket system is actually simpler electrically. Rather than two alternators with a relay system it uses one of the largest alternators you can buy, on all of the airplane's existing electrical circuit. You just have to beef up the battery cables and the circuit breaker on the alternator to handle the extra amperage. It took us 6 months and ultimately a suggestion that we have a particular engineering firm look at our plans. They were basically requiring us to re-approve the entire system, even though the system is approved in other airplanes with identical engines. All we needed approval for was a larger alternator (minimal change to weight/balance) and the repurposing of a material made by Boeing for the rear shelf (we told them we intended to use the floorboard material that Boeing puts in 737s, it's a fiberglass sheet reinforced internally with an aluminum honeycomb mesh, that can bear about twice the weight per square inch that we needed to put on it).
They made us have that engineering firm submit stress and load test data on the shelf material that Boeing already uses for the 737.
The only reason we jumped through all the hoops was the fact that the aftermarket A/C system's installer has a relative that was a 30 year Embraer engineer. He would just help us do the drawings and calculus for free as long as his son's maintenance shop was going to get the installation job. Absent that, the ~$25,000 job would've been a $50,000 job, which just isn't worth it for an airplane that's worth less than $175,000 to start with.
When we were willing to turn over the copyright of the plans to the engineering firm we were suggested to hire to "review" the data for the requested approval, including them copying and pasting Boeing's stress and load test data for the floor material Boeing already uses, suddenly the floodgates opened and everyone was happy. The paper was all signed and we got permission to put a marginally different air conditioner in one make and model of airplane (of which only 50 exist in the wild).
From initial sales call to cool air in my airplane: about 8 months.
The time to install it for two guys was about a week of shop time. After all, they put it in dozens of other makes/models and it's all the same stuff.
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If you want another example, you can go down the rabbit hole of a local (to me) company called Navworx, which was aggressively pursued and ultimately closed by the FAA, because the FAA changed the ADS-B spec rendering their ADS-B receiver worthless, after the spec had been in the field for about 3 or 4 years.
The AD...
There is a small graduated cylinder with a spike at the top it is pushed into a valve under the wing to get some fuel from that tank. You look to see if there is any water floating in the gas. After you check it you toss the leaded gas on the tarmac. Then you do the same for the other wing tank.
Airports especially small airports with piston powdered light aircraft using leaded avgas must be soaked in 70 years lead.
https://www.pooleys.com/shop/pooleys/the-gats-jar-fuel-teste...
Pretty common when there's a fog and you get condensate. The tank on a small airplane isn't gonna be sealed air-tight, it's vented to the outside air so a little condensate is pretty normal.
Water is heavier than the gas, so it sinks to the bottom where the drain fitting is.
Good god, I think I'd be chewed out if I did this at my field. Always back in the tank. Avgas is too expensive to dump it all over the ramp.
We take about 20-30ml in general (about half a shotglass)
Also the 7ml is not my figure. The "shotglass" is usally more than half full. I agree 7ml is not a lot.
https://youtu.be/mhMKTe3tkv0?t=4223
Bio-based is a minefield of a few ways to have it reasonably ok'ish (mostly if it's stuff that would otherwise be waste) and countless ways to produce more emissions than before. The latter is usually what happens...
I think it's highly preferable because many airports don't really want to be selling avgas anymore, and this will only become more of a problem as it's phased out. There's also a huge price difference.