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Now that 100UL has the FAA stamp of approval-

Austro engines passed the 2 million flight hour mark back in 2019 with their FADEC controlled AE series. Must be close to 3 million now given the increase in fleet size every year.

We'll reach an estimated 900,000 flight hours by next month with SDS and exceed 20 million hours in ground operation. No serious issues related to software. We've been supplying aviation with ECUs dating back to 1995 so this is hardly new or unproven technology.
 

That interview with Paul Millner was very enlightening, especially the comment that G100UL is very close to the WWII "fighter fuel" formulation with the use of xylene in place of toluene. The G100UL formulation was completed in a few months, the testing took years of data trying to prove a negative (a lot of negatives). Hard to imagine we won WWII without the FAA's help.

I look forward to the day I can fly somewhere and G100UL will likely be available on the field, and I can forget about adding Decalin.

John Salak
RV-12 N896HS
 
We'll reach an estimated 900,000 flight hours by next month with SDS and exceed 20 million hours in ground operation. No serious issues related to software. We've been supplying aviation with ECUs dating back to 1995 so this is hardly new or unproven technology.

Ross- Truly impressive, no denying that! You might even convince me (Mr. “I do not allow the operation of my engine to rely upon software-dependent devices”) to put software between me and my engine’s operation at some point. A personal requirement would, however, be fully redundant, non-interconnected, dual systems that would never receive simultaneous software or firmware updates.

To keep this just a little on topic, though, ALL of these side discussions are about engine configuration variants that all fall very neatly into the coverage of the G100UL STC.- Otis
 
OK

Just showed up on Barnstormers. CA politicians lobbying for total ban on Lead fuels in US.
I am OK with that, but the west coast airports from Alaska to Mexico all seem to use fuel refined at the Chevron Richmond refinery, according the the Avweb video. If they just ban the sale of leaded avgas at CA airports, fine. But if they ban the manufacturing of leaded fuel, then all those west coast airports from Alaska to Mexico will need to quickly convert to unleaded.
 
Just showed up on Barnstormers. CA politicians lobbying for total ban on Lead fuels in US.

I wouldn't worry about that. They can bark all they want, but we are currently in the middle of a pretty meaningfull pilot shortage and the only real path to making new pilots is through the GA fleet. Therefore, access to 100LL is of great importance to our national economy. They won't touch that with a 10 foot pole. On top of that, the FAA just approved a UL replacement, so why bother even if they did want to. At most, they just push the FAA to move a bit faster.

While CA could ban it in their state, I see about a 0% chance that they can get the Fed's to follow suit.

Did you follow the GMO labeling issue. Couple states passed laws requiring labels for products using GMO grain. Fed stepped in and passed a law within a month banning states from establishing laws requiring GMO labeling. Unfortunately this is no longer the same America you read about in the history books. Feds have pretty broad sweeping powers these days and no one seems to be complaining or revolting.

Larry
 
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But if they ban the manufacturing of leaded fuel, then all those west coast airports from Alaska to Mexico will need to quickly convert to unleaded.

That is an incredibly tall order and seems highly unlikely they could pull that off. Fed's likely to step in and put a halt to that. We have a limited number of refineries in this country that essentially cannot be relocated. No way that the Feds let the States start messing with them and risk cutting production. We are STILL feeling the effects of a two month shut down of the TX plants that make PVC pipe (made from refined crude) and that was 1.5 years ago.
 
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THREAD DRIFT ALERT.... Let's get back to topic for G100UL not EFI's, by order of self appointed internet hall monitor. ha ha.

A couple of thoughts come to mind-

1- With “No approved alternative” being pretty much the only remaining argument for legal availability of 100LL, how much time will pass before it becomes illegal, especially here in California? Might that motivate a rather speedy transition?
Yep there will be pressure to transition quickly and before availability, like the Car EV mandate. Three airports in California are reported to have already made moves to ban 100LL. We shall see. I hope there is steady progress in producing and distributing G100UL. Since they are interchangeable and can be mixed that may help.

2- I wonder if we will be seeing the return of semi-synthetic(or even fully synthetic?) aviation motor oil availability.
Synthetic aviation oil BLENDS are still in use. The PURE 100% synthetic oil of the past that failed badly in aircraft engines, likely not. Yes tetra-ethyl-lead (TEL) would build up because synthetic oil was a poor solvent, can not hold LEAD in suspension, and after 600-900 hours the rings and valve guides would get "glued". Another issue was full synthetic oils could not handle the high head / exhaust valve temperatures.

I get your point without tetra-ethyl-lead (TEL) the full synthetic may now work. I think there are still heat and particulate suspension issues. The success of the BLENDED "semi-synthetic" oils would not lead oil companies to go full synthetic. There is some complaints about blended semi synthetics already. Exxon is discontinuing their blended semi synthetic aviation oil.

Many well respect aviation mintenance experts swear by traditional single grade base oils for aircraft engines. Of course ALL OILS have synthetic chemical additives. All oils can be considered semi synthetic, except pure mineral oil used for break in. It is just a matter of percentage of base oil to synthetic additives. All "full" synthetic oils (even for cars) have some base oil as I understand it. The exception is Jet turbine engine oils. They are 100% synthetic. Jet engine oil is cleaner sans combustion products. Although the oil gets hot, it does not cook the oil like a piston engine exhaust valve guide does.
 
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.......The G100UL formulation was completed in a few months, the testing took years of data trying to prove a negative (a lot of negatives). Hard to imagine we won WWII without the FAA's help.

John Salak RV-12 N896HS
I am always a little skeptical. I wounder if the loss of tetra-ethyl-lead (TEL) will lower the lubrication quality of the fuel and increase valve guide and piston/cylinder wear.

Does anyone know if they did wear test? When automotive fuel went from tetra-ethyl-lead (TEL) to no lead older engines without hardened valve seats and guides wore out quickly.
 
I'm just curious, in auto racing we've had unleaded 100 octane for decades, running in all kinds of very high compression, high heat, carbs and FI.

Why can't this stuff just be adapted to run in aircraft engines?

I was wondering the same thing so I did some research. Automotive octane ratings are different than Aviation ratings. 100 avgas is around 110 auto. I'm not aware of any 110+ mogas that isn't leaded.
 
Racing fuel

When running amateur race cars, 100LL avgas was better than any racing fuel. Cheap too. If avgas is really equivalent to 110 car gas, that explains a lot.
 
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