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Unleaded Avgas Approved

185 points by another 5y ago

h2odragon 5y ago
404'd for me but I found this: https://www.aviationpros.com/gse/fueling-equipment-accessories/fuel-distributors-suppliers-manufacturers/press-release/21232119/general-aviation-modifications-inc-gami-first-ever-high-octane-unleaded-avgas-approved-by-faa https://www.aviationpros.com/gse/fueling-equipment-accessori...
- davidholdeman 5y ago
  And this: https://www.avweb.com/insider/gami-crosses-the-finish-line/ https://www.avweb.com/insider/gami-crosses-the-finish-line/
0xfaded 5y ago
Approval of specific airframes and engines through STCs (Supplementary Type Certificates) is slightly misleading. In the same way, regular unleaded gasoline is also approved through STCs for many airframes and engines. This isn’t the silver 1:1 bullet that replaces 100LL tomorrow. Nevertheless, I’m all for the 100LL alternatives efforts. If I was buying an aircraft, however, I would be more interested in a Jet-A burning piston (basically diesel). Unfortunately that market is currently limited to Diamond aircraft, which are fantastic if not for their tight grip on their service network.
- jacobmarble 5y ago
  I looked into using a diesel engine in an experimental aircraft (US/FAA definition). Unleaded car engines are fairly common in these planes. It turns out that Jet-A isn't necessarily good for a piston diesel engine, due to lubricity and cetane number. After enough reading, I decided to stick with unleaded/100LL until the day I can afford a proper turboprop. https://generalaviationnews.com/2011/03/17/jet-a-versus-diesel-fuel/ https://generalaviationnews.com/2011/03/17/jet-a-versus-dies... https://www.thedieselstop.com/threads/jet-a-vs-diesel.62296/ https://www.thedieselstop.com/threads/jet-a-vs-diesel.62296/ Having typed all this, when I was in Afghanistan with the US Army, the tactical trucks with diesel engines all ran on the same Jet-A that the aircraft used. I assume there was something different about that fuel, or the engines in those trucks.
  - throwawayboise 5y ago
    All diesel fuels are lower lubricity than they used to be (due to changes for modern low-emissions diesel engines). If you have an older diesel engine, you can use additives to restore lubricity, but I don't know if they are approved for use in Jet/A for a piston diesel aircraft.
  - wbl 5y ago
    Jet-A is Jet-A. It's the engines: the Army would like to avoid having to schlep around two kinds of fuel that can get confused to disastrous results.
    - jacobmarble 5y ago
      Yes, obviously. Safer to drive a diesel truck on Jet-A than a Chinook on diesel.
    - sokoloff 5y ago
      The Army is almost surely using JP-8, which is similar but not identical to Jet-A.
  - selectodude 5y ago
    >I assume there was something different about that fuel, or the engines in those trucks. Nope, it's just that the operational lifespan of those trucks isn't long enough for the Jet-A to really matter. It's only a major issue for the fuel pump, anyway. Those can always be replaced.
    - gnopgnip 5y ago
      Yep, most up armored Humvee or MRAPs will last less than 10k miles.
- briandear 5y ago
  Diamond’s are fine unless you need an airplane equivalent to a Cessna T206 or a 421. Diamonds, are really competing with Cirrus or the Cessna 172. As someone flying a 310 horsepower turbocharged 206, using an unleaded AvGas is a scary proposition. The only way to operate these turbo engines on current unleaded technology fuels would be to significantly reduce the boost pressure of the turbo and massively de-rate the engines. Flying heavy or out of hot or high airports would be significantly more dangerous. On normally aspirated 172s with a 160 or 180 horsepower engine, it would be less of a big deal. On a turbo-high performance engine, getting the performance out of the fuel is something not likely (hence the STC only for 172 lycomings.) Detonation would be the main risk or you’d have to use significantly less power which defeats the purpose. There are already mogas STCs. Until those fuels work in high performance engines, this isn’t really a groundbreaking thing. And just a point of fact, just because lead is “scary,” the actual environmental impact of leaded AvGas is trivial — despite the flawed “studies” put forth by the anti-airport lobby. If we want to improve the environment, I am all for it, but targeting AvGas is like trying to swat a fly circling a dead elephant. One Chinese factory spits out enough toxins in a day than the entire AvGas fleet does in a year. That’s not to say we shouldn’t work for better and cleaner airplane fuels, but in terms of environmental impact, this isn’t doing much. Resources would probably be better spent on lead and asbestos remediation in old, low income housing — or in the water supply. Kids aren’t getting sick from AvGas exhaust.
  - base698 5y ago
    How much are your annuals?
  - wffurr 5y ago
    >> The EPA's own studies have shown that to prevent a measurable decrease in IQ for children deemed most vulnerable, the standard needs to be set much lower, to 0.02 µg/m3. The EPA identified avgas as one of the most "significant sources of lead". Atmospheric lead is pretty dangerous, more so than encapsulated lead paint inside a wall.
    - lazide 5y ago
      That’s an incredibly misleading quote - do you have anything that can correlate atmospheric lead concentrations at ground level with flight hours or take/offs and landings somewhere?
- sidewndr46 5y ago
  Given the heavy handed way that lead was removed from fuel for passenger vehicles, I'm still perplexed that a tiny lobby has managed to keep it around basically indefinitely. If I were to build an aerial vehicle that sprayed a toxic substance everywhere it went, the environmental groups would basically go nuts. But somehow because it is in a plane, nothing ever really happens about it. The logical thing to do with 100LL is to ban it, like was done with passenger fuels. Existing planes serving a public good (basically just bush planes at this point) can continue to operate on it indefinitely. No sales of new planes equipped with engines that operate on 100LL would be allowed either.
  - jdhn 5y ago
    I'm willing to bet that the amount of lead that's put out by aircraft in a year pales in comparison to what was put out by cars, and as a result going after lead emissions from cars was deemed to be the best course of action by the EPA. Also, it's worth noting that leaded gasoline didn't go away overnight. It was still sold for awhile even after the EPA said that you couldn't make cars that ran on leaded gas.
  - pc86 5y ago
    Can you not see how passenger vehicles, which are overwhelmingly for personal use, is a different category with a different economic impact than an entire class of public transportation?
    - lmm 5y ago
      Gasoline-engined planes are overwhelmingly for personal use.
- GekkePrutser 5y ago
  I've seen 172 conversions with diesel. In fact that young guy that flew around the world in this 172 last week used one.
mgarfias 5y ago
Bout time
jakedata 5y ago
Some years ago I obtained a "barn find" vehicle that still had some 1970s leaded gasoline in the tank. After much work getting things ready to run, I decided the best thing to do with the old gasoline was to install a disposable fuel filter and just run it through the engine. The scent of leaded gas is something entirely different from modern products. Sweet-smelling and rather pleasant, it triggered childhood memories I didn't know I had. Of course knowing what leaded gasoline smells like could have contributed to other issues...
- gambiting 5y ago
  I have a fun trivia fact to share actually - here in UK, it's one of the only remaining places in the world where you can still legally buy leaded petrol for automotive use. Only a handful of garages around the country are certified to sell it, the prices are very high, but it's the ultimate fuel for people who want to preserve their old vehicles in original factory state, without modifying anything to run on unleaded fuel. Alternatively, the sale of leaded additive is still allowed(which literally just contains TEL - tetraethyl lead - effectively turning 95 unleaded into the old 4-star leaded). This website used to list the garages still selling leaded petrol, but they have changed the whole site very recently - so you can only see the list on wayback machine: http://web.archive.org/web/20210225112828/https://fbhvc.co.uk/fuels http://web.archive.org/web/20210225112828/https://fbhvc.co.u... TEL additive: https://www.classic-oils.net/TetraBOOST-E-Guard-15 https://www.classic-oils.net/TetraBOOST-E-Guard-15
  - adav 5y ago
    Is there a https://www.howmanyleft.co.uk https://www.howmanyleft.co.uk for numbers of leaded petrol cars still on the road?
    - gambiting 5y ago
      Not sure if that would be useful, as there's no way to confirm whether a vehicle that was designed for leaded fuel was converted for unleaded, or if it simply runs on non-leaded additives. Either way, there is this website, which used to really push for leaded petrol, it disappeared in 2009, but it almost reads like comedy: http://web.archive.org/web/20090101030343/http://www.leadedpetrol.co.uk/ http://web.archive.org/web/20090101030343/http://www.leadedp... " Don't forget, if your local filling station doesn't sell leaded petrol, ask them to start!" "Bayford is campaigning to have the extra duty on Leaded Petrol removed. You can help by printing this letter and sending it to your Member of Parliament"
underseacables 5y ago
Will this work in the old piston aircraft? I’m thinking about buffalo airways.
- iamtheworstdev 5y ago
  only if the engine doesn't need lead for lubrication of the valves/anything else
  - throwawayboise 5y ago
    There are other additives that can provide that, the question would be do they have FAA approval.
  - sokoloff 5y ago
    Lead does not lubricate the valves, though that's a common misconception. https://www.avweb.com/features/pelicans-perch-55lead-in-the-hogwash/ https://www.avweb.com/features/pelicans-perch-55lead-in-the-... (The fine author of this article sadly passed away earlier today.)
    - Syonyk 5y ago
      > The fine author of this article sadly passed away earlier today. Aw! :( I hadn't heard that yet. I'll have to read through Pelican's Perch again. So much knowledge, so densely collected.
- seabrookmx 5y ago
  Aviation gasoline or "avgas" is _only_ used for piston aircraft. Fuel for turbines is closer in makeup to Kerosene than it is gasoline, whether it's a traditional turbofan or a turboprop like you'd see on a Dash-8.
  - throwawayboise 5y ago
    Buffalo is famous for flying old DC-3s and some other small "bush" planes that are piston-engined.
bdash 5y ago
Per https://www.avweb.com/aviation-news/gami-awarded-long-awaited-stc-for-unleaded-100-octane-avgas/ https://www.avweb.com/aviation-news/gami-awarded-long-awaite..., this new unleaded fuel is currently only approved for Cessna 172s with Lycoming engines, with expansion to more aircraft types coming next year.
- jcutrell 5y ago
  Makes sense - the 172 is one of the most common training planes, getting a TON of low-altitude hours in the pattern. Also because of the low altitude flights 172s will probably run rich. Granted, they aren't burning a ton of fuel per hour - around 8g - but considering the sheer number of 172s out there this will make a reasonable dent in the total fleet of pistons. Though I expect the infra changes to actually support this will take a very long time to actually put in place, and many people will opt for 100LL for a long time because it is all that's available at their local airport or it is cheaper. I own a 182 that has the STC for auto-gas, and barely anyone sells auto-gas on-field. The only other option is to maintain my own tank, but that can't go on trips with me. Still good news in the long run.
  - jeffbee 5y ago
    8 gallons of 100LL contains about 4 grams of lead, enough to measurably lower the IQ of over 100000 children.
    - deleted 5y ago
      [deleted]
    - SomeHacker44 5y ago
      Would love to see the source and data on that, given that I use 1000s of gallons of leaded fuel a year.
      - jeffbee 5y ago
        "The study found that for each 5-microgram [per deciliter] increase in blood lead, a person lost about 1.5 IQ points." https://jamanetwork.com/journals/jama/fullarticle/2613157 https://jamanetwork.com/journals/jama/fullarticle/2613157
xyzzy21 5y ago
Except I sure as hell wouldn't put that in any plane that wasn't specifically designed for unleaded. Talk about setting yourself up for literal DEATH.
- univacboy 5y ago
  There are many older airplanes that were designed for much lower-lead fuel than is available now. 100LL ("Low Lead") still has several TIMES more lead than the 80 octane that would have been optimal in the older low-compression engines in use for many decades. There have been STCs (Supplemental Type Certificates) to make it legal to run unleaded auto gas in those engines; the problem with them currently is that they require gasoline without any ethanol, which is difficult to find in many places.
  - ncmncm 5y ago
    And the ethanol in US gasoline is there entirely to provide a market for Archer Daniels Midland to dump the alcohol it makes (under huge govt subsidy) to help absorb the huge (also very heavily subsidized!) overproduction of corn. The addition of sugar to practically all processed food in the US is another response to that massive overproduction. Excess sugar is responsible for the ongoing, massive public health disaster that absolutely dwarfs COVID19. (But we are OK with it.) And, feeding all livestock corn, despite its harm to their digestion and nutritive value of the result, just because it is the only way to be competitive. Earl Butz, Reagan's Sect. of Ag, has a lot to answer for in hell. But there is more than enough blame to go around. Anyone pushing for universal Medicare but not to eliminate corn subsidy is (at best) failing to address the root cause of the problem.
- bpodgursky 5y ago
  Please don't pollute the world with toxic brain-damaging chemicals out of stubborn inertia.
iamtheworstdev 5y ago
my personal guess is that this is going to lead to STCs that allow the installation of diesel engines as replacements for avgas engines. They're saying it's going to raise fuel by 40 to 80 cents (USD), so it'll probably be more than that. One of the pluses of AVGAS engines is that they can be overhauled repeatedly which saves on engine replacement costs over the life time of the plane. But the increase in fuel price is likely to bring it level with the replacement cost of a new diesel engine. Since diesels can run JET-A fuel, which is a global fuel source and much cheaper than AVGAS.. I just don't see how AVGAS engines survive in the long term. (older planes can't just adopt an electric engine. batteries are too heavy and the airframe won't be able to carry batteries that provide 600-800nm of range)
alistairSH 5y ago
Is the link wrong? I'm getting a 404.
Blackthorn 5y ago
I hope we can get it, or even 94UL (which is 100LL minus the lead) at airports soon. Many of us can run 94UL just fine, but there's nowhere it's available.
- sokoloff 5y ago
  Though many airplanes can, the working airplanes (that burn a lot of fuel) mostly cannot and if the FBO is faced with being able to sell fuel to all airplanes or just some with a tank and dispenser, it's a pretty easy call. The promise of G100UL is that that FBO can (eventually) sell this fuel to all gasoline-fueled airplanes.
  - Blackthorn 5y ago
    I know what the promise is. My point is I'd like any unleaded fuel at all to be available at the pump. Regardless of whether it needs to support the world's shittiest ancient engines or not.
    - sokoloff 5y ago
      Being able to support turbocharged engines is critical to being economically viable for FBOs which is critical to being actually available for sale. (Estimates were that 70% of the airplanes could use a 94UL-type gasoline, but that the 30% of remaining airplanes burned [and bought] 70% of the fuel sold, so a 94UL solution is, as you've experienced, not economically viable.)
      - ericd 5y ago
        Apologies, I’m not very familiar with aircraft engines, why can’t we simply use high octane unleaded gasoline, like most turbocharged car engines? Are the cylinder pressures significantly higher in airplane engines?
        sokoloff 5y ago
        Airplane engines are overwhelmingly air-cooled, fixed timing (after starting), pilot-controlled fueling, and expected to produce 100% of rated power for 5 minutes and then 65-75% of rated power for hours on end. Automotive engines are overwhelmingly water-cooled [providing a far more stable and lower cylinder head temperature], variable/computer-controlled timing often with knock sensing [providing the means to adjust timing dynamically when anything beyond light pinging is detected], closed-loop fuel control, and rarely producing more than 20% of their rated power. Aircraft engines need to stay together with a cylinder head temperature of 460ºF, fixed timing, and fuel mixtures that are set by the pilot. It's a far more demanding (and less controlled) environment. Some additional refs that might be interesting: https://www.avweb.com/features/pelicans-perch-43detonation-myths/ https://www.avweb.com/features/pelicans-perch-43detonation-m... https://www.avweb.com/features/pelicans-perch-55lead-in-the-hogwash/ https://www.avweb.com/features/pelicans-perch-55lead-in-the-... https://www.avweb.com/features_old/pelicans-perch-31those-fire-breathing-turbos-part-1/ https://www.avweb.com/features_old/pelicans-perch-31those-fi...
unchocked 5y ago
It's been a long time coming - manufacturer's been working on this for at least about a decade. What's important about this fuel is that it should work in _any_ application that requires leaded gas. The most demanding applications are a small % of the engines overall, but get the most hours and burn the most fuel. So we've been waiting for a drop-in replacement that can supplant leaded gas entirely (market is too small for multiple aviation gasolines to be effectively distributed). Of course, this is going to continue to take way longer to roll out than it should, but this first approval is a very big deal.
JamilD 5y ago
It’s a shame Light Sport Aircraft (LSAs) never really caught on. Most of them use Rotax engines which take regular unleaded gasoline. They’re much more fuel efficient too!
- plantain 5y ago
  Huh? LSA is doing fine. It does considerably better in basically every other jurisdiction where the licencing is typically easier and the payloads higher. “Comparing charts I see 506 registrations of LSA-type aircraft in 2020 and 358 registrations of GA aircraft in 2020,” Steve notes. “Thus, registrations of LSA-type aircraft account for more than half of the single-engine piston aircraft registered in 2020, 59% from data analyzed for this report.” https://generalaviationnews.com/2020/11/02/up-or-down-how-flies-the-lsa-industry-in-this-strange-year/ https://generalaviationnews.com/2020/11/02/up-or-down-how-fl...
  - phkahler 5y ago
    I think the problem with LSAs was the industry adopted them too fast. There were so many manufacturers none of them could the volume needed for lower prices. Even Cessna canceled the C162. This has been improving over time of course.
  - nameless912 5y ago
    And there's scuttlebutt that the LSA rules might be revised to be based off a load factor formula rather than a fixed upper gross weight limit, as well as the creation of PSAs (larger aircraft certified via ASTM standards rather than FAA part 31(? I can't remember the CFR part right now), which would allow for much faster and easier certification of PSAs (as opposed to standard category aircraft). Here's hoping for a full revision to the LSA rules that allows 152/72/82 and Piper Cherokees into the category; that would open up Sport pilots to thousands of new aircraft they were unable to fly for essentially no reason. It's painfully obvious that the FAA's artificial limitation of 1320 lbs was completely arbitrary and is overall a detriment to the safety of pilots operating under the sport rules. Frankly, I think/hope that recertifying the majority of standard category aircraft as PSAs will help drive down costs and spur some new innovation in GA.
verst 5y ago
I can't realistically imagine the FBOs (fuel providers) at many airports providing a type of fuel only approved for C172s with Lycoming engines. I fly out of Boeing Field (KBFI). Often the FBOs have issues with their fuel trucks or simply don't provide service. You have to taxi to their ramp. The wait can be significant - and that's with just one type of 100LL fuel. Sometimes it's better to fly over to KPWT (Bremerton National), an uncontrolled airport, and use their self service Avgas station with a credit card.
- sokoloff 5y ago
  I think the C172-only limitation is clearly interim. GAMI's been burning this in testing for a decade or so. Now, put it into a lot of low-powered trainers. Based on that experience, expand it to other engines and airframes. The end game is an all-models STC; this is an interim step (and a massive one to get the FAA to go from zero-to-one approved models).
codetrotter 5y ago
“Avgas” in Swedish means “exhaust”, as in what you get from the tail pipe of a car. But I can’t tell if their use of the name “Avgas” for the product here is intentionally connected to the Swedish meaning of that word or not.
- throwawayboise 5y ago
  It is a contraction of "aviation gasoline"
- AlotOfReading 5y ago
  It's referring to avgas, a shortened name for aviation gasoline. I don't believe there's a relationship to the swedish. Historically there was also a corresponding mogas (motor gasoline), but the specifier got dropped in general usage.
Robotbeat 5y ago
It’s crazy to me that we’ve allowed leaded gasoline in general aviation for this long. The price of rebuilding all general aviation engines to take lower octane fuel (or possibly ethanol, which has very high octane but a few caveats) has got to be FAR less than the public/mental health burden of allowing leaded avgas.
- sokoloff 5y ago
  It's not that simple. If there was a way to "rebuild" the engine (which happens around every 1500-2500 hours of operation naturally) and maintain the current performance on an unleaded fuel, it probably would have been mandated already*. (As someone who would bear that cost, I'd absolutely have supported the action and happily paid the money.) The problem is that turbocharged airplane engines (the ones powering heavy, fast, working airplanes that buy/burn a lot of fuel) are already working close to the ragged edge of safe detonation limits on 100 octane fuel. Switching to a 95 or 96 octane fuel that contains no lead would not provide the same level of detonation margin, meaning that the engines could not produce the same level of power as originally certified, meaning that the approved performance data in the flight manuals would no longer be correct, meaning that the FAA would ground them. The exciting thing about this week's announcement is that G100UL represents a credible path to certifying an unleaded fuel that's compatible and miscible with 100LL [for the transition period] and preserves the detonation margin and performance that the airplanes were originally certified with. * This is not a matter of "install hardened valve seats and motor on" like we did with classic cars.
  - Robotbeat 5y ago
    Ethanol and other such fuels have even higher octane. And yes, it WOULD suck in the interim, would have been more disruptive to general aviation, range would have been impacted (in the case of alcohols), but this is such a MASSIVE public health issue, it would clearly have been worth it IMHO. Pilots would’ve absolutely hated it, but the wrath of pilots is not a good enough reason to justify lead emissions over the last several decades which may have depressed intelligence and increased crime rate. I am NOT saying this wouldn’t have had negative, perhaps even massive, temporary disruptions in general aviation, including grounding some planes. I am saying it would be worth it.
brnt 5y ago
Can someone tell me why liquid fuel is called gas in the US?
- nickff 5y ago
  "Gas" is short for "gasoline", just like "petrol" is short for "petroleum".
- potiuper 5y ago
  https://en.wikipedia.org/wiki/Gasoline#Etymology https://en.wikipedia.org/wiki/Gasoline#Etymology
NelsonMinar 5y ago
GAMI is a super interesting and innovative company. They also pioneered the practice of using precision-balanced fuel injectors to help plane engines run more smoothly. Factory engines come with radically unbalanced fuel injection, one cylinder might get 10-20% more fuel than others. GAMI developed a procedure for you to test the imbalance in your engine and then sell you a set of balanced injector. That saves fuel, wear on the engine, and even lets you run lean of peak more safely if you want.

185 points by another 5y ago

404'd for me but I found this: https://www.aviationpros.com/gse/fueling-equipment-accessories/fuel-distributors-suppliers-manufacturers/press-release/21232119/general-aviation-modifications-inc-gami-first-ever-high-octane-unleaded-avgas-approved-by-faa https://www.aviationpros.com/gse/fueling-equipment-accessori...

davidholdeman 5y ago
And this: https://www.avweb.com/insider/gami-crosses-the-finish-line/ https://www.avweb.com/insider/gami-crosses-the-finish-line/

0xfaded 5y ago

Approval of specific airframes and engines through STCs (Supplementary Type Certificates) is slightly misleading. In the same way, regular unleaded gasoline is also approved through STCs for many airframes and engines. This isn’t the silver 1:1 bullet that replaces 100LL tomorrow. Nevertheless, I’m all for the 100LL alternatives efforts. If I was buying an aircraft, however, I would be more interested in a Jet-A burning piston (basically diesel). Unfortunately that market is currently limited to Diamond aircraft, which are fantastic if not for their tight grip on their service network.

jacobmarble 5y ago
I looked into using a diesel engine in an experimental aircraft (US/FAA definition). Unleaded car engines are fairly common in these planes. It turns out that Jet-A isn't necessarily good for a piston diesel engine, due to lubricity and cetane number. After enough reading, I decided to stick with unleaded/100LL until the day I can afford a proper turboprop. https://generalaviationnews.com/2011/03/17/jet-a-versus-diesel-fuel/ https://generalaviationnews.com/2011/03/17/jet-a-versus-dies... https://www.thedieselstop.com/threads/jet-a-vs-diesel.62296/ https://www.thedieselstop.com/threads/jet-a-vs-diesel.62296/ Having typed all this, when I was in Afghanistan with the US Army, the tactical trucks with diesel engines all ran on the same Jet-A that the aircraft used. I assume there was something different about that fuel, or the engines in those trucks.
- throwawayboise 5y ago
  All diesel fuels are lower lubricity than they used to be (due to changes for modern low-emissions diesel engines). If you have an older diesel engine, you can use additives to restore lubricity, but I don't know if they are approved for use in Jet/A for a piston diesel aircraft.
- wbl 5y ago
  Jet-A is Jet-A. It's the engines: the Army would like to avoid having to schlep around two kinds of fuel that can get confused to disastrous results.
  - jacobmarble 5y ago
    Yes, obviously. Safer to drive a diesel truck on Jet-A than a Chinook on diesel.
  - sokoloff 5y ago
    The Army is almost surely using JP-8, which is similar but not identical to Jet-A.
- selectodude 5y ago
  >I assume there was something different about that fuel, or the engines in those trucks. Nope, it's just that the operational lifespan of those trucks isn't long enough for the Jet-A to really matter. It's only a major issue for the fuel pump, anyway. Those can always be replaced.
  - gnopgnip 5y ago
    Yep, most up armored Humvee or MRAPs will last less than 10k miles.
briandear 5y ago
Diamond’s are fine unless you need an airplane equivalent to a Cessna T206 or a 421. Diamonds, are really competing with Cirrus or the Cessna 172. As someone flying a 310 horsepower turbocharged 206, using an unleaded AvGas is a scary proposition. The only way to operate these turbo engines on current unleaded technology fuels would be to significantly reduce the boost pressure of the turbo and massively de-rate the engines. Flying heavy or out of hot or high airports would be significantly more dangerous. On normally aspirated 172s with a 160 or 180 horsepower engine, it would be less of a big deal. On a turbo-high performance engine, getting the performance out of the fuel is something not likely (hence the STC only for 172 lycomings.) Detonation would be the main risk or you’d have to use significantly less power which defeats the purpose. There are already mogas STCs. Until those fuels work in high performance engines, this isn’t really a groundbreaking thing. And just a point of fact, just because lead is “scary,” the actual environmental impact of leaded AvGas is trivial — despite the flawed “studies” put forth by the anti-airport lobby. If we want to improve the environment, I am all for it, but targeting AvGas is like trying to swat a fly circling a dead elephant. One Chinese factory spits out enough toxins in a day than the entire AvGas fleet does in a year. That’s not to say we shouldn’t work for better and cleaner airplane fuels, but in terms of environmental impact, this isn’t doing much. Resources would probably be better spent on lead and asbestos remediation in old, low income housing — or in the water supply. Kids aren’t getting sick from AvGas exhaust.
- base698 5y ago
  How much are your annuals?
- wffurr 5y ago
  >> The EPA's own studies have shown that to prevent a measurable decrease in IQ for children deemed most vulnerable, the standard needs to be set much lower, to 0.02 µg/m3. The EPA identified avgas as one of the most "significant sources of lead". Atmospheric lead is pretty dangerous, more so than encapsulated lead paint inside a wall.
  - lazide 5y ago
    That’s an incredibly misleading quote - do you have anything that can correlate atmospheric lead concentrations at ground level with flight hours or take/offs and landings somewhere?
sidewndr46 5y ago
Given the heavy handed way that lead was removed from fuel for passenger vehicles, I'm still perplexed that a tiny lobby has managed to keep it around basically indefinitely. If I were to build an aerial vehicle that sprayed a toxic substance everywhere it went, the environmental groups would basically go nuts. But somehow because it is in a plane, nothing ever really happens about it. The logical thing to do with 100LL is to ban it, like was done with passenger fuels. Existing planes serving a public good (basically just bush planes at this point) can continue to operate on it indefinitely. No sales of new planes equipped with engines that operate on 100LL would be allowed either.
- jdhn 5y ago
  I'm willing to bet that the amount of lead that's put out by aircraft in a year pales in comparison to what was put out by cars, and as a result going after lead emissions from cars was deemed to be the best course of action by the EPA. Also, it's worth noting that leaded gasoline didn't go away overnight. It was still sold for awhile even after the EPA said that you couldn't make cars that ran on leaded gas.
- pc86 5y ago
  Can you not see how passenger vehicles, which are overwhelmingly for personal use, is a different category with a different economic impact than an entire class of public transportation?
  - lmm 5y ago
    Gasoline-engined planes are overwhelmingly for personal use.
GekkePrutser 5y ago
I've seen 172 conversions with diesel. In fact that young guy that flew around the world in this 172 last week used one.

mgarfias 5y ago

Bout time

jakedata 5y ago

Some years ago I obtained a "barn find" vehicle that still had some 1970s leaded gasoline in the tank. After much work getting things ready to run, I decided the best thing to do with the old gasoline was to install a disposable fuel filter and just run it through the engine. The scent of leaded gas is something entirely different from modern products. Sweet-smelling and rather pleasant, it triggered childhood memories I didn't know I had. Of course knowing what leaded gasoline smells like could have contributed to other issues...

gambiting 5y ago
I have a fun trivia fact to share actually - here in UK, it's one of the only remaining places in the world where you can still legally buy leaded petrol for automotive use. Only a handful of garages around the country are certified to sell it, the prices are very high, but it's the ultimate fuel for people who want to preserve their old vehicles in original factory state, without modifying anything to run on unleaded fuel. Alternatively, the sale of leaded additive is still allowed(which literally just contains TEL - tetraethyl lead - effectively turning 95 unleaded into the old 4-star leaded). This website used to list the garages still selling leaded petrol, but they have changed the whole site very recently - so you can only see the list on wayback machine: http://web.archive.org/web/20210225112828/https://fbhvc.co.uk/fuels http://web.archive.org/web/20210225112828/https://fbhvc.co.u... TEL additive: https://www.classic-oils.net/TetraBOOST-E-Guard-15 https://www.classic-oils.net/TetraBOOST-E-Guard-15
- adav 5y ago
  Is there a https://www.howmanyleft.co.uk https://www.howmanyleft.co.uk for numbers of leaded petrol cars still on the road?
  - gambiting 5y ago
    Not sure if that would be useful, as there's no way to confirm whether a vehicle that was designed for leaded fuel was converted for unleaded, or if it simply runs on non-leaded additives. Either way, there is this website, which used to really push for leaded petrol, it disappeared in 2009, but it almost reads like comedy: http://web.archive.org/web/20090101030343/http://www.leadedpetrol.co.uk/ http://web.archive.org/web/20090101030343/http://www.leadedp... " Don't forget, if your local filling station doesn't sell leaded petrol, ask them to start!" "Bayford is campaigning to have the extra duty on Leaded Petrol removed. You can help by printing this letter and sending it to your Member of Parliament"

underseacables 5y ago

Will this work in the old piston aircraft? I’m thinking about buffalo airways.

iamtheworstdev 5y ago
only if the engine doesn't need lead for lubrication of the valves/anything else
- throwawayboise 5y ago
  There are other additives that can provide that, the question would be do they have FAA approval.
- sokoloff 5y ago
  Lead does not lubricate the valves, though that's a common misconception. https://www.avweb.com/features/pelicans-perch-55lead-in-the-hogwash/ https://www.avweb.com/features/pelicans-perch-55lead-in-the-... (The fine author of this article sadly passed away earlier today.)
  - Syonyk 5y ago
    > The fine author of this article sadly passed away earlier today. Aw! :( I hadn't heard that yet. I'll have to read through Pelican's Perch again. So much knowledge, so densely collected.
seabrookmx 5y ago
Aviation gasoline or "avgas" is _only_ used for piston aircraft. Fuel for turbines is closer in makeup to Kerosene than it is gasoline, whether it's a traditional turbofan or a turboprop like you'd see on a Dash-8.
- throwawayboise 5y ago
  Buffalo is famous for flying old DC-3s and some other small "bush" planes that are piston-engined.

bdash 5y ago

Per https://www.avweb.com/aviation-news/gami-awarded-long-awaited-stc-for-unleaded-100-octane-avgas/ https://www.avweb.com/aviation-news/gami-awarded-long-awaite..., this new unleaded fuel is currently only approved for Cessna 172s with Lycoming engines, with expansion to more aircraft types coming next year.

jcutrell 5y ago
Makes sense - the 172 is one of the most common training planes, getting a TON of low-altitude hours in the pattern. Also because of the low altitude flights 172s will probably run rich. Granted, they aren't burning a ton of fuel per hour - around 8g - but considering the sheer number of 172s out there this will make a reasonable dent in the total fleet of pistons. Though I expect the infra changes to actually support this will take a very long time to actually put in place, and many people will opt for 100LL for a long time because it is all that's available at their local airport or it is cheaper. I own a 182 that has the STC for auto-gas, and barely anyone sells auto-gas on-field. The only other option is to maintain my own tank, but that can't go on trips with me. Still good news in the long run.
- jeffbee 5y ago
  8 gallons of 100LL contains about 4 grams of lead, enough to measurably lower the IQ of over 100000 children.
  - deleted 5y ago
    [deleted]
  - SomeHacker44 5y ago
    Would love to see the source and data on that, given that I use 1000s of gallons of leaded fuel a year.
    - jeffbee 5y ago
      "The study found that for each 5-microgram [per deciliter] increase in blood lead, a person lost about 1.5 IQ points." https://jamanetwork.com/journals/jama/fullarticle/2613157 https://jamanetwork.com/journals/jama/fullarticle/2613157

xyzzy21 5y ago

Except I sure as hell wouldn't put that in any plane that wasn't specifically designed for unleaded. Talk about setting yourself up for literal DEATH.

univacboy 5y ago
There are many older airplanes that were designed for much lower-lead fuel than is available now. 100LL ("Low Lead") still has several TIMES more lead than the 80 octane that would have been optimal in the older low-compression engines in use for many decades. There have been STCs (Supplemental Type Certificates) to make it legal to run unleaded auto gas in those engines; the problem with them currently is that they require gasoline without any ethanol, which is difficult to find in many places.
- ncmncm 5y ago
  And the ethanol in US gasoline is there entirely to provide a market for Archer Daniels Midland to dump the alcohol it makes (under huge govt subsidy) to help absorb the huge (also very heavily subsidized!) overproduction of corn. The addition of sugar to practically all processed food in the US is another response to that massive overproduction. Excess sugar is responsible for the ongoing, massive public health disaster that absolutely dwarfs COVID19. (But we are OK with it.) And, feeding all livestock corn, despite its harm to their digestion and nutritive value of the result, just because it is the only way to be competitive. Earl Butz, Reagan's Sect. of Ag, has a lot to answer for in hell. But there is more than enough blame to go around. Anyone pushing for universal Medicare but not to eliminate corn subsidy is (at best) failing to address the root cause of the problem.
bpodgursky 5y ago
Please don't pollute the world with toxic brain-damaging chemicals out of stubborn inertia.

iamtheworstdev 5y ago

my personal guess is that this is going to lead to STCs that allow the installation of diesel engines as replacements for avgas engines. They're saying it's going to raise fuel by 40 to 80 cents (USD), so it'll probably be more than that. One of the pluses of AVGAS engines is that they can be overhauled repeatedly which saves on engine replacement costs over the life time of the plane. But the increase in fuel price is likely to bring it level with the replacement cost of a new diesel engine. Since diesels can run JET-A fuel, which is a global fuel source and much cheaper than AVGAS.. I just don't see how AVGAS engines survive in the long term. (older planes can't just adopt an electric engine. batteries are too heavy and the airframe won't be able to carry batteries that provide 600-800nm of range)

alistairSH 5y ago

Is the link wrong? I'm getting a 404.

Blackthorn 5y ago

I hope we can get it, or even 94UL (which is 100LL minus the lead) at airports soon. Many of us can run 94UL just fine, but there's nowhere it's available.

sokoloff 5y ago
Though many airplanes can, the working airplanes (that burn a lot of fuel) mostly cannot and if the FBO is faced with being able to sell fuel to all airplanes or just some with a tank and dispenser, it's a pretty easy call. The promise of G100UL is that that FBO can (eventually) sell this fuel to all gasoline-fueled airplanes.
- Blackthorn 5y ago
  I know what the promise is. My point is I'd like any unleaded fuel at all to be available at the pump. Regardless of whether it needs to support the world's shittiest ancient engines or not.
  - sokoloff 5y ago
    Being able to support turbocharged engines is critical to being economically viable for FBOs which is critical to being actually available for sale. (Estimates were that 70% of the airplanes could use a 94UL-type gasoline, but that the 30% of remaining airplanes burned [and bought] 70% of the fuel sold, so a 94UL solution is, as you've experienced, not economically viable.)
    - ericd 5y ago
      Apologies, I’m not very familiar with aircraft engines, why can’t we simply use high octane unleaded gasoline, like most turbocharged car engines? Are the cylinder pressures significantly higher in airplane engines?
      - sokoloff 5y ago
        Airplane engines are overwhelmingly air-cooled, fixed timing (after starting), pilot-controlled fueling, and expected to produce 100% of rated power for 5 minutes and then 65-75% of rated power for hours on end. Automotive engines are overwhelmingly water-cooled [providing a far more stable and lower cylinder head temperature], variable/computer-controlled timing often with knock sensing [providing the means to adjust timing dynamically when anything beyond light pinging is detected], closed-loop fuel control, and rarely producing more than 20% of their rated power. Aircraft engines need to stay together with a cylinder head temperature of 460ºF, fixed timing, and fuel mixtures that are set by the pilot. It's a far more demanding (and less controlled) environment. Some additional refs that might be interesting: https://www.avweb.com/features/pelicans-perch-43detonation-myths/ https://www.avweb.com/features/pelicans-perch-43detonation-m... https://www.avweb.com/features/pelicans-perch-55lead-in-the-hogwash/ https://www.avweb.com/features/pelicans-perch-55lead-in-the-... https://www.avweb.com/features_old/pelicans-perch-31those-fire-breathing-turbos-part-1/ https://www.avweb.com/features_old/pelicans-perch-31those-fi...

unchocked 5y ago

It's been a long time coming - manufacturer's been working on this for at least about a decade. What's important about this fuel is that it should work in _any_ application that requires leaded gas. The most demanding applications are a small % of the engines overall, but get the most hours and burn the most fuel. So we've been waiting for a drop-in replacement that can supplant leaded gas entirely (market is too small for multiple aviation gasolines to be effectively distributed). Of course, this is going to continue to take way longer to roll out than it should, but this first approval is a very big deal.

JamilD 5y ago

It’s a shame Light Sport Aircraft (LSAs) never really caught on. Most of them use Rotax engines which take regular unleaded gasoline. They’re much more fuel efficient too!

plantain 5y ago
Huh? LSA is doing fine. It does considerably better in basically every other jurisdiction where the licencing is typically easier and the payloads higher. “Comparing charts I see 506 registrations of LSA-type aircraft in 2020 and 358 registrations of GA aircraft in 2020,” Steve notes. “Thus, registrations of LSA-type aircraft account for more than half of the single-engine piston aircraft registered in 2020, 59% from data analyzed for this report.” https://generalaviationnews.com/2020/11/02/up-or-down-how-flies-the-lsa-industry-in-this-strange-year/ https://generalaviationnews.com/2020/11/02/up-or-down-how-fl...
- phkahler 5y ago
  I think the problem with LSAs was the industry adopted them too fast. There were so many manufacturers none of them could the volume needed for lower prices. Even Cessna canceled the C162. This has been improving over time of course.
- nameless912 5y ago
  And there's scuttlebutt that the LSA rules might be revised to be based off a load factor formula rather than a fixed upper gross weight limit, as well as the creation of PSAs (larger aircraft certified via ASTM standards rather than FAA part 31(? I can't remember the CFR part right now), which would allow for much faster and easier certification of PSAs (as opposed to standard category aircraft). Here's hoping for a full revision to the LSA rules that allows 152/72/82 and Piper Cherokees into the category; that would open up Sport pilots to thousands of new aircraft they were unable to fly for essentially no reason. It's painfully obvious that the FAA's artificial limitation of 1320 lbs was completely arbitrary and is overall a detriment to the safety of pilots operating under the sport rules. Frankly, I think/hope that recertifying the majority of standard category aircraft as PSAs will help drive down costs and spur some new innovation in GA.

verst 5y ago

I can't realistically imagine the FBOs (fuel providers) at many airports providing a type of fuel only approved for C172s with Lycoming engines. I fly out of Boeing Field (KBFI). Often the FBOs have issues with their fuel trucks or simply don't provide service. You have to taxi to their ramp. The wait can be significant - and that's with just one type of 100LL fuel. Sometimes it's better to fly over to KPWT (Bremerton National), an uncontrolled airport, and use their self service Avgas station with a credit card.

sokoloff 5y ago
I think the C172-only limitation is clearly interim. GAMI's been burning this in testing for a decade or so. Now, put it into a lot of low-powered trainers. Based on that experience, expand it to other engines and airframes. The end game is an all-models STC; this is an interim step (and a massive one to get the FAA to go from zero-to-one approved models).

codetrotter 5y ago

“Avgas” in Swedish means “exhaust”, as in what you get from the tail pipe of a car. But I can’t tell if their use of the name “Avgas” for the product here is intentionally connected to the Swedish meaning of that word or not.

throwawayboise 5y ago
It is a contraction of "aviation gasoline"
AlotOfReading 5y ago
It's referring to avgas, a shortened name for aviation gasoline. I don't believe there's a relationship to the swedish. Historically there was also a corresponding mogas (motor gasoline), but the specifier got dropped in general usage.

Robotbeat 5y ago

It’s crazy to me that we’ve allowed leaded gasoline in general aviation for this long. The price of rebuilding all general aviation engines to take lower octane fuel (or possibly ethanol, which has very high octane but a few caveats) has got to be FAR less than the public/mental health burden of allowing leaded avgas.

sokoloff 5y ago
It's not that simple. If there was a way to "rebuild" the engine (which happens around every 1500-2500 hours of operation naturally) and maintain the current performance on an unleaded fuel, it probably would have been mandated already*. (As someone who would bear that cost, I'd absolutely have supported the action and happily paid the money.) The problem is that turbocharged airplane engines (the ones powering heavy, fast, working airplanes that buy/burn a lot of fuel) are already working close to the ragged edge of safe detonation limits on 100 octane fuel. Switching to a 95 or 96 octane fuel that contains no lead would not provide the same level of detonation margin, meaning that the engines could not produce the same level of power as originally certified, meaning that the approved performance data in the flight manuals would no longer be correct, meaning that the FAA would ground them. The exciting thing about this week's announcement is that G100UL represents a credible path to certifying an unleaded fuel that's compatible and miscible with 100LL [for the transition period] and preserves the detonation margin and performance that the airplanes were originally certified with. * This is not a matter of "install hardened valve seats and motor on" like we did with classic cars.
- Robotbeat 5y ago
  Ethanol and other such fuels have even higher octane. And yes, it WOULD suck in the interim, would have been more disruptive to general aviation, range would have been impacted (in the case of alcohols), but this is such a MASSIVE public health issue, it would clearly have been worth it IMHO. Pilots would’ve absolutely hated it, but the wrath of pilots is not a good enough reason to justify lead emissions over the last several decades which may have depressed intelligence and increased crime rate. I am NOT saying this wouldn’t have had negative, perhaps even massive, temporary disruptions in general aviation, including grounding some planes. I am saying it would be worth it.

brnt 5y ago

Can someone tell me why liquid fuel is called gas in the US?

nickff 5y ago
"Gas" is short for "gasoline", just like "petrol" is short for "petroleum".
potiuper 5y ago
https://en.wikipedia.org/wiki/Gasoline#Etymology https://en.wikipedia.org/wiki/Gasoline#Etymology

NelsonMinar 5y ago

GAMI is a super interesting and innovative company. They also pioneered the practice of using precision-balanced fuel injectors to help plane engines run more smoothly. Factory engines come with radically unbalanced fuel injection, one cylinder might get 10-20% more fuel than others. GAMI developed a procedure for you to test the imbalance in your engine and then sell you a set of balanced injector. That saves fuel, wear on the engine, and even lets you run lean of peak more safely if you want.