[HN Gopher] Unleaded Avgas Approved
___________________________________________________________________
Unleaded Avgas Approved
Author : another
Score : 122 points
Date : 2021-07-28 14:02 UTC (4 hours ago)
(HTM) web link (www.avweb.com)
(TXT) w3m dump (www.avweb.com)
| h2odragon wrote:
| 404'd for me but I found this:
| https://www.aviationpros.com/gse/fueling-equipment-accessori...
| davidholdeman wrote:
| And this: https://www.avweb.com/insider/gami-crosses-the-
| finish-line/
| unchocked wrote:
| 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.
| alistairSH wrote:
| Is the link wrong? I'm getting a 404.
| verst wrote:
| 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 wrote:
| 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).
| xyzzy21 wrote:
| 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.
| bpodgursky wrote:
| Please don't pollute the world with toxic brain-damaging
| chemicals out of stubborn inertia.
| univacboy wrote:
| 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 wrote:
| 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.
| jakedata wrote:
| 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 wrote:
| 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.u...
|
| TEL additive:
|
| https://www.classic-oils.net/TetraBOOST-E-Guard-15
| adav wrote:
| Is there a https://www.howmanyleft.co.uk for numbers of
| leaded petrol cars still on the road?
| gambiting wrote:
| 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.leaded
| p...
|
| " 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"
| derriz wrote:
| "If you run a classic or high performance car, now is the
| time to throw away that can of additive, and fill up with
| award winning genuine leaded petrol"
| drcongo wrote:
| In London last summer I caught a whiff of a smell that I
| hadn't smelled in years - 30 seconds later a vintage Jag came
| around the corner and I realised it was the exhaust of a car
| running leaded petrol. I was struck by the fact that I could
| literally smell it coming.
| sokoloff wrote:
| That may have been from uncatalysed exhaust. My '66 Mustang
| also has a very distinctive smell, despite running an
| unleaded fuel.
| pitaj wrote:
| Sweet smell can also be from running ethanol-rich fuels.
| xyzzy21 wrote:
| All European gasoline used to smell like that not so long ago.
| It's one of the major memories of my first trip to European as
| a teen.
| avian wrote:
| "Not so long" must be somewhere in early 90s. Most of Europe
| phased out leaded gasoline by 2000.
|
| From my experience the thing that affects the exhaust smell
| more than leaded/unleaded is whether the engine has a
| catalytic converter. A car without the converter running on
| unleaded will have the same sweet smell the parent is talking
| about.
| cmrdporcupine wrote:
| The gas stations themselves used to have a different smell.
|
| I remember as a child (in Canada) somehow enjoying the
| smell when my parents filled up on gas. Which is kind of
| terrifying in retrospect.
| tapland wrote:
| I faintly remember. I'd probably be interested in having
| the weirdest irl meet up over a car found with a spare
| jug of leaded gas. Reliving old smells does so much for
| creativity
| bluGill wrote:
| I remember that. I also remember unleaded had the same
| smell. Though this was 40 years ago so who knows if my
| memory is right.
| pomian wrote:
| There are a lot of issues with the leaded replacement
| gasolines. Lead was at least heavy, and "fell" close to it's
| point of use. The BTEX components added to gasoline after
| removing the lead, are carcinogenic. They are also volatile.
| They go everywhere, and affect everyone. Overall, neither the
| biological or human ecology are better off. The politics behind
| the leaded gasoline change is fascinating, as most of the other
| environmental decisions are, when studied from the point of
| view of toxicology and environmental science.
| henearkr wrote:
| Lead accumulates in the body poisons you for far longer than
| the other chemicals you mention.
|
| Even with relative to the particular effects on health, you
| really can't compare lead and those others. Lead was really
| the worse.
| hammock wrote:
| Where can I read more about this?
| tapland wrote:
| Yes this seems like a very interesting, important and
| overlooked issue.
| nawgz wrote:
| I also think the fellow stating that we are not better
| off for having unleaded fuel is overstating the matter.
| Lead in fuel was quite strongly correlated with crime
| rates, no?
| cartoonworld wrote:
| Wrt health effects of gasoline, it is bad for you full stop.
|
| The chemistry should be improved or changed if needed,
| however leaded (pb) fuel should never return. We are
| definitely better off.
| clukic wrote:
| Interesting to note that unleaded gas also has lead about 0.05g
| per gallon which is a lot when you consider how much gas is
| burned in a typical big city everyday. Aviation gas has 2 grams
| per gallon, so if you live near an airport you're probably
| getting a pretty steady diet of lead.
| nate_meurer wrote:
| The EPA limits unleaded gasoline to 0.5 g/gal, but that
| doesn't mean your gasoline actually contains that much. The
| regs are meant to forgive some amount of cross-contamination
| from facilities that also handle avgas. I don't have any
| information on what values are typically encountered.
|
| You're right, 0.5 g/gal is a lot of lead.
| axiak wrote:
| The actual amount of gallons of gas burned in planes using
| AVGas is extremely small compared to the gallons of gas
| burned by cars or by planes using jet fuel. Unless you were
| on the tarmac with prop planes running, I doubt you'd smell
| the lead.
| lostlogin wrote:
| > 2 grams per gallon
|
| I'm from a fully metric land, is the above a common way to
| express a ratio? It certainly stuck out to me but it's a
| pretty tidy measure.
| jjoonathan wrote:
| Hey, it doesn't even have internal unit cancellation or
| convention ambiguity like "kilowatt hours per month". We
| can do worse!
| Robotbeat wrote:
| 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.
| underseacables wrote:
| Will this work in the old piston aircraft? I'm thinking about
| buffalo airways.
| iamtheworstdev wrote:
| only if the engine doesn't need lead for lubrication of the
| valves/anything else
| sokoloff wrote:
| Lead does not lubricate the valves, though that's a common
| misconception.
|
| https://www.avweb.com/features/pelicans-perch-55lead-in-
| the-... (The fine author of this article sadly passed away
| earlier today.)
| throwawayboise wrote:
| There are other additives that can provide that, the question
| would be do they have FAA approval.
| JamilD wrote:
| 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 wrote:
| 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-fl...
| phkahler wrote:
| 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.
| JamilD wrote:
| I guess it's just based on my observations in the US. I'm a
| Sport Pilot; I don't see many others in the Bay Area.
|
| Often I'm the only one that rents the Skycatcher at KPAO in a
| given month, and there's basically only two LSAs that are
| accessible to rent nearby (that Skycatcher at KPAO and a
| SportStar at KRHV).
| nameless912 wrote:
| 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.
| cameldrv wrote:
| I think that the dream was that you were going to see $50k new
| aircraft due to the easier regulation, but it didn't pan out,
| and new LSAs are more like $150k. When you can get a used 172
| for the same money and have a far more capable aircraft, that's
| the direction most people end up going.
|
| I could see some resurgence in the market with the large number
| of late-70s light aircraft starting to become unmaintainable
| though. It's hard to say with the opposing force of the
| shrinking pilot population though.
| bdash wrote:
| Per 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 wrote:
| 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 wrote:
| 8 gallons of 100LL contains about 4 grams of lead, enough to
| measurably lower the IQ of over 100000 children.
| [deleted]
| SomeHacker44 wrote:
| Would love to see the source and data on that, given that I
| use 1000s of gallons of leaded fuel a year.
| jeffbee wrote:
| "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
| [deleted]
| unchocked wrote:
| You're conflating chronic and acute exposure. Pop
| epidemiology 101.
| kube-system wrote:
| The saving grace is that your exhaust doesn't go directly
| into the bloodstreams of children, likely most of the
| lead ends up at other places on earth.
| wffurr wrote:
| >> 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 ug/m3. The EPA identified avgas as one of the most
| "significant sources of lead".
|
| Maybe stop?
| sokoloff wrote:
| That's the point of the GAMI fuel approval: it provides a
| practical path to stop using 100LL.
| throwaway0a5e wrote:
| You can't just take the mass of the lead and then assume it
| all winds up in humans.
|
| For a given amount of lead output into the atmosphere lead
| output over an airport is going to get into people's blood
| a lot less efficiently than lead output in an automotive
| context.
| bpodgursky wrote:
| ... so we're just going to slowly build up base-level
| contamination in the soil, water, and ecosystem? Let's
| not?
| throwaway0a5e wrote:
| I'm not endorsing lead emissions, just pointing out that
| emitting them not into people is a lot better than
| emitting them fairly directly into people.
|
| While obviously it would not be ideal to evenly
| distribute lead evenly throughout the surface of the
| earth lead is a fairly common element and exists in
| ground deposits more or less worldwide without poisoning
| people. It's not as common as iron but it was used for
| all sorts of thing historically specifically because of
| how common (and therefore cheap) it is/was.
| henearkr wrote:
| Well, NO, lead tetraethyl is not naturally present. It's
| a human-made metallo-organic molecule.
| lazide wrote:
| Elemental lead is nearly completely insoluble and very
| difficult to absorb. If entrained in dirt, even more so.
| Breathing vapors or aerosolized fine powders isn't great,
| but uptake even then isn't high compared to many other
| toxic substances - that is usually the dominant form
| however. It usually requires some kind direct ingestion +
| acid exposure of a significant amount of lead, or
| breathing in a large quantity of lead vapor or fine dust
| to get notable exposure.
|
| Which is exactly what you get when every car in a city
| was burning tetra ethyl lead in large quantities, and/or
| kids were eating sweet tasting lead paint chips.
|
| Leaded AVgas is a concern, but dilution of the resulting
| lead from combustion gets diluted very widely very
| quickly resulting in actual low concentrations. And since
| it's not 'every car in the LA basin', it just isn't at
| the scope or scale of a problem you're making it out to
| be. We're probably having bigger issues from all the
| random new stuff companies put into tires (including
| carbon nanotubes now), which then gets ground up and
| dispersed as fine power at the million ton scale every
| day.
|
| Lead is not mobile in typical soil or water environments,
| and as long as the water isn't strongly acidic, it
| settles out and stays where it lands. There is naturally
| occurring trace lead in most soils - it's a somewhat
| common element.
| nate_meurer wrote:
| Contaminated soils don't contain elemental lead. The
| dominant form is lead oxide, one of the two common
| additives in lead paint (along with the carbonate) and
| also the end point of the combustion of TEL in fuel. Lead
| from lead oxide is easily absorbed orally from soil,
| paint chips, and household dust, and it's also a serious
| inhalation hazard.
|
| > _sweet tasting lead paint chips_
|
| What makes you think lead paint tastes sweet?
|
| > _Lead is not mobile in typical soil or water
| environments_
|
| Which is exactly the reason lead-contaminated soils are
| such a long-lasting hazard. It's the reason little kids
| playing in the dirt around old houses can be poisoned
| decades after contamination was laid down. For example,
| here in Denver entire urban neighborhoods were built on
| the site of a smelter that was demolished a hundred years
| ago, and the contamination is still largely unchanged.
| Remediation requires completely replacing the top several
| feet of soil.
|
| > _There is naturally occurring trace lead in most soils
| - it's a somewhat common element._
|
| Significant deposits of lead in surface soil are rare,
| and are limited to sites with unique geology. The vast
| majority of distributed lead in surface soils is of human
| origin.
| sokoloff wrote:
| > What makes you think lead paint tastes sweet?
|
| Lead acetate has a sweet taste. Lead paint flakes/dust
| contain lead acetate.
|
| https://www.smithsonianmag.com/arts-culture/sugar-of-
| lead-a-...
| henearkr wrote:
| Lead tetraethyl is _not_ elemental lead.
|
| I think you are mixed up.
|
| Lead tetraethyl (the component found in lewded gas) _is_
| easily absorbed, it even diffuses through skin to the
| blood!
| sokoloff wrote:
| Once combusted, the exhaust contains primarily lead oxide
| (PbO), not TEL (C8H20Pb)
| Blackthorn wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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 wrote:
| 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?
| btgeekboy wrote:
| At least one airport I know of - KAWO - used to have it, but no
| longer does. Wonder what the story is there.
| 0xfaded wrote:
| 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.
| sidewndr46 wrote:
| 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 wrote:
| 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 wrote:
| 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?
| briandear wrote:
| 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 wrote:
| How much are your annuals?
| wffurr wrote:
| >> 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
| ug/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 wrote:
| 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?
| sneak wrote:
| Note that the word most is not in the quote from the
| source.
| jacobmarble wrote:
| 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-dies...
|
| 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.
| wbl wrote:
| 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 wrote:
| Yes, obviously. Safer to drive a diesel truck on Jet-A than
| a Chinook on diesel.
| sokoloff wrote:
| The Army is almost surely using JP-8, which is similar but
| not identical to Jet-A.
| selectodude wrote:
| >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 wrote:
| Yep, most up armored Humvee or MRAPs will last less than
| 10k miles.
| throwawayboise wrote:
| 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.
| mgarfias wrote:
| Bout time
| codetrotter wrote:
| "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 wrote:
| It is a contraction of "aviation gasoline"
| AlotOfReading wrote:
| 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.
| iamtheworstdev wrote:
| 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)
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