[HN Gopher] FAA approves unleaded fuel for piston fleet
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FAA approves unleaded fuel for piston fleet
Author : sokoloff
Score : 167 points
Date : 2022-09-01 20:50 UTC (2 hours ago)
(HTM) web link (www.aopa.org)
(TXT) w3m dump (www.aopa.org)
| sokoloff wrote:
| Original headline seemed far less communicative (and was far too
| long to use in the submission), so I did the best I could to
| faithfully summarize.
|
| For the record, the original headline/subheadline is:
| GA moves closer to unleaded future FAA approves GAMI
| unleaded avgas STCs covering piston fleet
| [deleted]
| throwawayx134ax wrote:
| This is great! Expect the EPA and the FAA to finally ban 100LL,
| which will be a great boon for everyone. Note, you will require
| an STC, but not poising yourself with lead will probably net out
| the costs in the long run.
|
| * I am a pilot of piston engines, and I really don't like 100LL
| being the only option
| V-eHGsd_ wrote:
| ul94 has been around for a year or so (I've had the stc since
| last december), but yeah for high compression engines, it was
| 100LL or nothing. I'm hoping the stc is comparably priced, $100
| or so.
|
| this is really awesome.
|
| edit to add: for the non av geeks, an stc is a supplemental
| type certificate. it's basically an faa stamp that says, "this
| aircraft has been changed from when it was initially certified,
| but it's an approved change"
|
| https://en.wikipedia.org/wiki/Supplemental_type_certificate
| sokoloff wrote:
| George Braly in the video interview indicated it would be
| similarly priced to the Petersen STC, which used to be
| $1/rated HP and now appears to be $2/rated HP.
|
| In short: it's no barrier whatsoever to adoption.
| V-eHGsd_ wrote:
| so a little more expensive than the swift stc but yeah
| still totally worth it.
| mips_avatar wrote:
| I live by lake union in Seattle, and I love watching the
| seaplanes taking off and landing. It's high time that there's a
| lead-free option. Seattle doesn't need that kind of lead in its
| air.
| verst wrote:
| As someone who flies GA aircraft out of Boeing field (KBFI) I
| also welcome this change. I don't want more leaded fuel on my
| hands. The lead can be absorbed by skin.
| walrus01 wrote:
| The rotary engine tech in a DHC beaver is barely changed from
| WW2 era rotary piston engines... Assuming we're not talking
| about the more modern turbine beavers and otters.
|
| The turbine ones already run on Jet-A
| itslennysfault wrote:
| I used to live near there too. I was today years old when I
| learned those planes still use leaded fuel. Oof. Glad that's
| getting rectified.... finally.
| cibyr wrote:
| The piston engines still use "low lead" fuel. The turboprops
| run on jet fuel.
| dfgert wrote:
| I am shocked to read this. Why are they still using leaded fuel?
| There are so many well known research that links lead in fuel to
| unstable mental health and crime in population.
| andrepd wrote:
| Well you see, you're not thinking that upper-middle class to
| upper class folks would have to give up their hobby.
|
| And yes, most piston airplanes fall into this category of
| recreational flying.
| neximo64 wrote:
| It's a rather cynical take.
|
| Some small regions in many countries can't even be accessed
| if it wasn't for a Cessna due to lack of demand, places that
| take up to 3 days by motorcycle. The fuel mix is basically
| copied worldover.
|
| Americans never realise they're the upper-middle class to the
| rest of the world.
| M3L0NM4N wrote:
| Some piston engines are really high compression and it's hard
| to prevent knocking without leaded fuel.
| NikolaNovak wrote:
| Nice. I hope this ushers approvals across the planet. I am just
| starting the journey to private license in Canada and I kinda
| hate how inefficient, but also how primitive and unhealthy the
| engines and fuel are :-/
| samstave wrote:
| >> _Nice. I hope this ushers approvals across the planet._
|
| TBH - this will just shift sales of that fuel type to the still
| "dirty" countries fuel supplies where banning it will not
| happen, sadly.
|
| Oil companies are not our friends.
|
| -
|
| I was just thinking about this yesterday; the amount of human
| infrastructure built around the petro-chem industry:: Land use,
| pollution, corruption, just plain evil, etc...
|
| Along with the fact they lobby and get subsidies and everything
| where the Earth provides their raw input for "free" and the
| rest of the world suffers.
|
| /r/fuckcars, but seriously - Petro-chem, for all the great
| things industrial revolution has given us, is the most
| insidious industry on the planet. Look at fucking ARAMCO's
| cap/profits last year. Largest company on the planet. BigOil is
| a nightmare.
| sokoloff wrote:
| 100LL is blended regionally to serve the piston engine
| demand.
|
| I expect that blending will switch to G100UL and there's
| nothing remaining to export to "'dirty' countries". As a
| consequence, the one remaining source of TEL in the world
| will close down within a decade. This is all overwhelmingly
| good as compared to yesterday's condition.
| avalys wrote:
| The engines are actually fairly efficient. Unlike an automobile
| engine, they really only operate in a very narrow range and are
| usually run at a substantial fraction of full power (60% or
| more).
|
| Automobile engines are very challenging because the power
| demands are highly variable and they can't be optimized for any
| specific load.
| bombcar wrote:
| Amusingly enough the Piper Cherokee I flew got better _ground
| gas mileage_ than the '66 Fury I had at the time.
| ketzo wrote:
| Wow, that's a hilarious stat. How is that even... possible?
| sokoloff wrote:
| 1960s cars were terribly inefficient is a big part of the
| story.
| NonNefarious wrote:
| It's quite possible for a plane to net higher mileage
| than many cars today, especially light-sport planes that
| only burn 5 gallons per hour or so.
| bombcar wrote:
| The '66 Fury weighs in at 3500 pounds and got about 10-12
| miles per gallon based on my pump-to-pump odometer tests.
|
| The Piper Cherokee PA-28-140 weighs a petite 2150 pounds
| (max loaded weight) and burns 10 gallons an hour and
| would do about 115 KIAS, which translated to roughly 130
| miles per hour ground speed, which is 13 miles per
| gallon.
|
| It would do even better if you flew for efficiency, but
| since rental was by hours of engine time wet (I didn't
| pay for fuel and would be reimbursed for fuel purchased),
| there was really no reason to not throttle that baby up
| to full rental power.
| NikolaNovak wrote:
| I guess it depends. I understand some ultralights and new
| airplanes may be efficient. But it is my understanding that a
| Cessna 172 lycoming is basically 50-70 years old, depending
| on how you count, and horribly inefficient, and completely
| prevalent. Faa certification for new engines is such that
| innovation is stifled. I mean it took the industry what, 3-4
| decades _and counting_ , to phase out leaded fuel which we
| all agree is God awful :-0
| avalys wrote:
| That's my point, the Lycoming (while an old design) is not
| all that inefficient.
|
| A Cessna 172 burns about 8 gallons per hour and travels at
| 125 knots, or about 140 mph. That's the equivalent of about
| 18 mpg.
|
| There's been an enormous improvement in automobile engine
| efficiency in the past 30 years, and most of that has come
| from optimizing engines and transmissions to minimize their
| fuel consumption under light load, while still giving them
| enough peak power capacity to accelerate quickly, tow a
| heavy load up a hill when needed, etc.
|
| In comparison, an aircraft engine spends very little time
| "idling" and sees very little change in load over the
| course of a flight. It just runs at a fixed speed and power
| setting for most of the time. There isn't that much to
| optimize or improve.
| maximilianburke wrote:
| There's tons to optimize!
|
| Timing is a big one; magento fired engines have fixed
| timing. The engines can't remove or add timing to get
| more power.
|
| Fuel ratios are determined by the pilot with current
| Lycoming and Continentals. Why should the pilot need to
| worry about this? EFI has been around for 40 years now
| and would help decrease the cognitive load on the pilot.
| Like, how many engines have cooked valves because the
| pilot (or student) forgot to richen the mixture before
| descending?
|
| Cooling is a huge one. There are a few liquid cooled
| aircraft engines and they just make everything easier.
| The engines are more reliable, and it also removes a
| carbon monoxide poisoning risk due to corrosion in the
| exhaust cuff.
|
| Yeah, a Cessna can get better fuel economy than a car
| traveling at 140mph but it could be _so much better_ than
| what it is. And not just better fuel economy, but better
| all around experience for the pilots (lower cognitive
| load), and owners (lower cost of living, more reliable
| engines).
| avalys wrote:
| I'm not disputing that GA engines could be significantly
| improved and modernized in numerous ways. But none of the
| improvements you mention actually relate to efficiency at
| cruise power.
| jdhn wrote:
| >better all around experience for the pilots (lower
| cognitive load)
|
| Can you elaborate further on this? Is this lower
| cognitive load because the engine is more reliable?
| sokoloff wrote:
| Many racecars and boats also run fixed timing. Variable
| timing is needed when the load is variable. If the load
| is constant, the timing can be fixed.
|
| Modern engine monitors have given us more insight than
| ever into engine operation and I don't find the engine
| management particularly taxing.
|
| After initial takeoff, I'm likely to set the power
| (throttle, RPM, and fuel mixture) at 1000' above the
| ground and not touch it again for 4 hours (when it's time
| to transition to landing).
| maximilianburke wrote:
| That's still not particularly efficient. There's still
| variable load: circuit work, obstacles to climb over,
| flying around (or into) airspace. Air density isn't
| fixed, your engine may be running richer or leaner than
| you need to be. Pilots aren't nearly as efficient as
| setting the mixture as a computer, nor are the currently
| used single injector (or carburetor) as efficient as
| multi-point, or direct, fuel injection.
|
| GAMI got their start selling more balanced fuel
| injectors, but there's only so much you can do when you
| squirt gas into a tube and hope that it makes it equally
| to all cylinders.
|
| There's a _lot_ on the table in terms of efficiency and
| it puzzles me why there has been almost zero progress on
| this front.
| sokoloff wrote:
| The C172 (most common small airplane) has a Lycoming
| 4-cylinder engine of various sizes throughout the years. A
| representative engine, the O-320, is around 89% as
| efficient as traditional (non-hybrid, non-Atkinson) ICE
| automobile at turning gasoline into productive work.
|
| I don't view an 11% spread as "horribly inefficient" given
| the need for many redundant systems, air-cooling, high
| diameter pistons, and relatively low RPM.
|
| 0-https://michaelsoroka.com/2014/03/26/are-airplane-
| engines-in...
| nimish wrote:
| They lack a bunch of emissions control equipment like
| fuel injection, catalytic converters, and the like.
|
| They are 60's or maybe 80's car engines that are still
| made since nobody in GA wants to pay for better ones.
| laverya wrote:
| > since nobody in GA wants to pay for better ones.
|
| Since nobody wants _to pay to certify_ better ones.
|
| The engine in a Cessna 172 is going to run you $20-40k
| (20k rebuilt, 40k new afaict - check out [0]) - _far_
| more expensive than an automobile engine with
| 'equivalent' performance. The difference is that the
| Lycoming is certified by the FAA for use with your
| airframe. (And it'll work in whatever conditions you care
| to name, and with a car engine that's only a 'probably')
|
| 0: https://www.coronaengines.com/In-Stock
| jcoby wrote:
| > They lack a bunch of emissions control equipment like
| fuel injection, catalytic converters, and the like.
|
| Yeah unfortunately the weight and size of those systems
| is prohibitive for most light aircraft. Plus catalytic
| converters and oxygen sensors for closed loop efi can't
| be used with leaded fuel.
|
| > They are 60's or maybe 80's car engines that are still
| made since nobody in GA wants to pay for better ones.
|
| The Lycoming and continental engines in most of the fleet
| were certified in the early 50s. A few were in the early
| 60s. That means they were designed in the 40s and 50s!
| kurupt213 wrote:
| How do they replace the lubricating function of the triethyl
| lead?
| bmismyname wrote:
| Fun fact: many major US cities still have lead pipes[1]. It costs
| about $20,000 to replace a lead service line from the water main
| to your home if you live in an older home/building, and the
| cities are not exactly working hard to replace lead mains.
|
| The cheapest way to lower your risk of lead exposure is to
| install an RO filter if you believe there are lead pipes (there
| are many different brands, but the one from APEC is popular and
| affordable). It has the added benefit of reducing exposure to
| other nasty things which have pretty much contaminated all the
| drinking water on earth like PFAS.
|
| I have an unsubstantiated pet theory on correlation between lead
| poisoning and crime in poorer neighbourhoods due to landlords
| refusing to replace these (why bother if you don't have to drink
| the water? landlords have no incentive so long as they can
| extract rents).
|
| In many cities you can get your water tested for free by the
| city, just do some searching. They've usually got an online form
| you can fill out and they'll send you a kit that you have to send
| back.
|
| [1]: https://www.nrdc.org/resources/lead-pipes-are-widespread-
| and...
| [deleted]
| clamprecht wrote:
| How will California cities justify closing general aviation
| airports now?
| GoOnThenDoTell wrote:
| Noise
| V-eHGsd_ wrote:
| noise.
|
| "the airplanes landing at this airport that was here when I
| moved are very loud and should not be allowed to land here
| anymore."
| ajsnigrutin wrote:
| This is a standard in my country but with farm smells and
| noises. People buy a house "in the country", then they
| complain about manure on fields, cows mooing and tractor
| noises.
| toomuchtodo wrote:
| Previous: https://news.ycombinator.com/item?id=30943466
| humanwhosits wrote:
| I sure hope they ban the leaded fuel soon
| sv123 wrote:
| Wow, I can't believe they got it done. After watching all the
| Paul Bertorelli videos on it I assumed it would be stuck in
| bureaucracy from here to eternity. Incredible work by the whole
| team, very exciting.
| NonNefarious wrote:
| Agreed, but sadly it's still a niche fuel. Although I have to
| admit that for a (hopefully) brief time, we've seen airplane
| gas and corner-gas-station gas the same price in California!
|
| I think that unless a large number of GA airplanes can run on
| true automotive gas (which means gasohol now) in the near
| future, GA is doomed. This is something the industry should
| have been tackling with abandon for the last 20 years. But they
| failed to take lead seriously for the last 50, so can we expect
| better?
|
| Maybe. I think there is one Rotax engine that can run on
| gosohol (10% ethanol). We need much more of that, and
| widespread adoption of fuel injection and electronic ignition
| ASAP.
|
| Oh, and we need more people to stand up for their local
| airports. Corrupt local politicians, developers, and fake-NIMBY
| land speculators are all arrayed to destroy our nation's
| aviation infrastructure for personal profit. Even airlines are
| in on it. Innovations like this unleaded fuel and
| electrification will cease if there's no place to deploy them.
| maxerickson wrote:
| Ethanol free gas is widely available (In Michigan stations
| call it Rec fuel).
|
| Are you concerned about cost, availability, some other
| factor?
| sokoloff wrote:
| "George Braly, chief engineer at GAMI, said the fuel can be
| made with components "that are found inside the fence of any
| refinery.""
|
| Now, that quote comes from the principal at GAMI and in a
| GAMI newsletter, but over the last decade and a half of
| following this, I've found him to be pretty damned
| straightforward.
|
| https://gami.com/g100ul/AvGas0211.pdf
| boppo1 wrote:
| Lowering the financial barrier to entry would help. Idk how,
| but part of the industry's problem is that people who want to
| learn to fly can't afford to.
| LadyCailin wrote:
| I don't want more incompetent people flying planes, so I'm
| content to keep it expensive enough to keep out people that
| aren't going to take it deadly serious - because it is.
| Expense doesn't guarantee that, of course, but it limits
| the collateral damage.
| stevage wrote:
| Huh. I had no idea leaded fuel was still a thing in aviation.
| mmaunder wrote:
| Jet fuel is unleaded. It's also pretty close to diesel, and
| some aircraft manufacturers have diesel piston engines that can
| use JetA. The leaded culprit is AVGas aka 100LL which we use in
| piston general aviation aircraft.
| na85 wrote:
| It lets you run comparatively higher manifold pressures than an
| otherwise identical but unleaded fuel.
| bombcar wrote:
| More importantly most aviation engines were designed in the
| 50-70s and need the lead to keep the valves happy.
| NonNefarious wrote:
| It's about detonation; I don't think it's about the valves.
| p_l wrote:
| Another issue is that replacements for TEL that were fine
| for cars had issues with high altitudes (and high ambient
| temperatures)
| maximilianburke wrote:
| Only because the engines themselves haven't evolved to handle
| higher manifold pressures. Lots of advancements in internal
| combustion engines, like combustion chamber and piston shapes
| that help manage the flame front, direct injection, wideband
| O2 sensors, are entirely unknown in certificated aircraft and
| still on the periphery even in experimental aviation.
|
| Like, Mazda is running 14:1 compression ratios in gasoline
| engines, but 7:1 is considered normal for a naturally
| aspirated Lycoming and it'll often dip into the 6's for
| turbocharged versions.
| sokoloff wrote:
| Mazda sold 332,756 vehicles in 2021.
|
| Cessna has the best selling model of airplane of all time,
| the 172, which has sold around 45K units _since its
| introduction in 1956_.
|
| Mazda sells that many cars in a typical 2 month period.
| It's no surprise that there's more non-recurring
| engineering investment in car engines than airplane
| engines.
| maximilianburke wrote:
| I mean, okay? I get that. But it's not like the Cessna
| 172 is a $25k item either, it's now over $400k.
|
| There have been tons of advances in general aviation,
| look at panel technology between now and 15 years ago.
| That's awesome! Let's do the same thing but for engines
| now. But it isn't going to happen as long as no one is
| pushing for it; we have the efficiency in automobiles we
| do now because regulators have been pushing for better
| fuel consumption and lower emissions for decades. It'd be
| great if there was similar pressure applied to aviation.
|
| I'd love to have a 172 that had no mixture knob and no
| issues with hot starts. Man, wouldn't that be awesome?
| This is what we should be asking for, not apologizing for
| why we're stuck with mechanical FI, carb heat, and shock
| cooling worries.
| tialaramex wrote:
| For cars, the argument was, if you used unleaded fuel and (as
| it might because the engine was designed for leaded gasoline)
| this causes engine damage, your engine is broken, which is sad,
| but you can just repair it. The failures are annoying, but
| they're unlikely to get anybody killed. You can just walk from
| the broken-down vehicle to somewhere with food and shelter and
| call a rescue truck.
|
| Even in countries like the UK which offered limited exemptions
| for "classic" cars, the fuel companies don't care, selling a
| few thousand litres per year of this weird special fuel makes
| no sense at their scale, so even with a regulation allowing
| this, it quickly died out. It was (maybe even still is?) legal
| to buy leaded gasoline ("petrol") in the UK for a really old
| car, but that's useless because nobody will sell it to you,
| it's just not profitable at the incredibly low volumes. Classic
| owners who run with leaded fuel these days buy their own
| additives and mix it at home, but also these cars are getting
| fragile, they probably belong in a museum anyway, not clocking
| up miles driving around, and in a museum display they don't
| need fuel.
|
| However if an aircraft engine dies, even though pilots of
| single engine piston aircraft are trained to assume that will
| happen in any phase of flight (because it can) that's extremely
| dangerous, complete engine failure over mountainous terrain
| could mean that your _best case scenario_ becomes trying to
| land your plane (well, now glider) in some untried clearing and
| if you survive then maybe needing to walk out because in some
| cases nobody is looking for you. So engine failures translate
| into fatalities at a significant rate.
|
| Planes are very expensive, and so they have long lives, which
| means many aeroplanes built long before leaded fuel was
| prohibited are still flying.
|
| On the other hand, notice this is about piston planes. So,
| you're mostly talking about smaller planes for personal use,
| and maybe some agricultural or business purposes but less
| often. For scheduled aviation, you're never going to be on a
| piston plane. To a layman it's less obvious because although
| they don't have piston engines lots of smaller or shorter range
| planes have propellers like an old-timey plane. But their
| propeller is driven by a jet engine, and that runs on JetA -
| kerosene fuel not leaded gasoline:
| https://en.wikipedia.org/wiki/Turboprop
| sokoloff wrote:
| What you said is overwhelmingly true, but there are some
| scheduled flights in piston twin C402s and the like (Cape Air
| being one of the larger operators of piston scheduled airline
| flights).
|
| https://www.capeair.com/
| throwaway0a5e wrote:
| Seems like every discussion about anything slightly
| environmental had some lead related low effort comments about
| "it's 202x, why is leaded avgas still a thing?".
|
| I won't miss those.
|
| I won't miss the lead either.
| panzagl wrote:
| I'm sure the 'problem X only exists because America doesn't
| have walkable cities' crowd will take up the slack.
| NonNefarious wrote:
| I was going to say that I don't know why you're getting
| modded down... but then plenty of those trolls probably
| frequent HN.
| [deleted]
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(page generated 2022-09-01 23:00 UTC)