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PAFI. What killed Swift Fuel candidate

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It's not quite like that, Ross. The FAA has not changed the spec, first of all. The fuel standard is still ASTM D910 and the engine test plans developed during PAFI 1.0 are still used. What is different now is that both the FAA and fuel suppliers have learned from previous mistakes.

The PAFI entry standards are now stricter than ever and include more materials testing so that the previous mistakes aren't repeated. This will keep out fuels that just don't have what it takes to be a "drop in" for 100LL. Is it challenging to meet this high standard, absolutely. Is it impossible, absolutely not.

The real question is whether the regulators and pilots will have the patience to wait for a proven answer or throw caution to the wind. Time will tell.

I am not aware that any of the original or current formulations met the specific gravity spec. Did/ do any?
 
I am not aware that any of the original or current formulations met the specific gravity spec. Did/ do any?

I think that is the Achilles heel to all of this; they do not want to have a POH change due to a mass / range difference. This is why I think others are staying away from the PAFI and using STC instead. JMHO.
 
I think that is the Achilles heel to all of this; they do not want to have a POH change due to a mass / range difference. This is why I think others are staying away from the PAFI and using STC instead. JMHO.

Agree. No fuel is "drop in" if it weighs 4-7% more than 100LL.
 
I think that is the Achilles heel to all of this; they do not want to have a POH change due to a mass / range difference. This is why I think others are staying away from the PAFI and using STC instead. JMHO.

You are correct John. The FAA and industry (i.e the PAFI Steering group) set the bar very high for drop-in fuels to minimize changes and potential safety issues. So yes, you can get limited approval for your fuel via the STC process, but PAFI is the still the only way to get fleet-wide approval.

But it's not only about density, it's about EVERYTHING. Materials compatibility, detonation resistance, aircraft operation, maintenance, spark plug intervals, range, cost, toxicity, emissions, cost, and cost.

The FAA is now fully committed to PAFI, especially after the limitations of the STC route have begun to sink in. The program just got a second wind and this time, it won't repeat the errors of PAFI 1.0. Stay tuned.
 
The FAA is now fully committed to PAFI, especially after the limitations of the STC route have begun to sink in. The program just got a second wind and this time, it won't repeat the errors of PAFI 1.0. Stay tuned.

I'll stay tuned, but are the fuel makers committed to working inside PAFI? If nobody wants to play the game again, nothing will happen any time soon. As they say- Fool me once...

The email responses I got from 2 of the players last month certainly made it seem like they were weary of the experience and the fact that some dropped out of it says something too.

All the players knew the specs to meet yet couldn't meet them all before. Maybe they've learned a lot from the first time around and can crack the formula the 2nd time around. I remain skeptical in the near term however unless some specs are relaxed, as has been suggested by others.

I hope I am wrong and this really happens in my flying lifetime.
 
I am not aware that any of the original or current formulations met the specific gravity spec. Did/ do any?

ASTM D910, the specification for 100LL and other leaded aviation gasoline grades, does not have a density spec. It calls for the producer to report it. However, as you know, fuel density is a very important property as it impacts fuel flow and energy density. FBO 100LL typically has a density of 5.85-6.0 lbs/gallon. Fuels with high aromatic content can have densities in the 6.2-6.4 range. This effectively can add 1/2 pound per gallon of fuel to the aircraft, or 30-45 lbs to a fully fueled Cessna 182 depending on the model.

There are at least 3 unleaded fuels that have densities in the 100LL range; UL94, the two fuels vying for PAFI qualification, and possibly Swift's UL100R. UL94 is not approved for turbocharged engines but the three others may eventually be. GAMI announced at OSHKOSH that G100UL weighs ~6.3 lbs/gallon which is 0.4-0.5 lbs/gallon denser than 100LL. This is consistent with the specs listed in their 2019 patent.
 

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Good info. I didn't realize the wide range of specific gravity permitted and they actually don't list this in any references I found, only specify as per ASTM D 1298 and 4052.
 
I'll stay tuned, but are the fuel makers committed to working inside PAFI? If nobody wants to play the game again, nothing will happen any time soon. As they say- Fool me once...

All the players knew the specs to meet yet couldn't meet them all before. Maybe they've learned a lot from the first time around and can crack the formula the 2nd time around. I remain skeptical in the near term however unless some specs are relaxed, as has been suggested by others.

I hope I am wrong and this really happens in my flying lifetime.

It's not really about the specs, Ross. It's about the testing protocols. Many fuels can meet D910 specs but cannot pass PAFI detonation or durability tests. That's because D910 was designed around leaded hydrocarbon fuels with minimum specs that are barely acceptable in some engines (and I am being generous). Remove the lead, and you have to change the chemistry of the fuel, which creates a whole new set of variables PAFI 1.0 and the fuel offerors had not anticipated.

So these are uncharted waters that require expert navigating. Fortunately, there are a lot of shipwrecks out there from the first attempt that are markers for those coming behind them.

Do not despair. Some may already have the answer. They just need to prove it to themselves, the FAA, the industry, and legitimate skeptics like you. :)
 
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A specification is by definition a set of technical requirements that something must meet. In this case many, based on multiple tests outlined by ASTM:

http://www.aviation-fuel.com/pdfs/avgas100llspecsastmd910_2011.pdf

Acceptance of the product would require completing all the tests here outlined in the specification.

Indeed. ASTM D910 is a specification for leaded AVGAS based on hydrocarbon-based fuels and it was developed decades ago. For unleaded fuels or fuels relying on non-hydrocarbon components, new ASTM specifications are being developed and will need to be balloted and approved by the ASTM J02 and D02 bodies.

Not all the tests in D910 are required to prove that a fuel is "fit-for-purpose", but data will need to be provided to demonstrate that deviations from D910 do not cause operational or performance issues. That's the point of the PAFI program and ASTM D7826 "Standard Guide for Evaluation of New Aviation Gasolines and New Aviation Gasoline Additives".

STC applicants are not required to provide an industry standard like D910. They can provide a "supplier specification" and just enough data to get the local ACO to grant an STC for a set of engines and aircraft.

So ASTM D910 will ultimately become irrelevant when a suitable alternative fuel is developed, granted fleet-wide approval by the FAA, and a new ASTM specification balloted and approved.
 
Interesting info indeed and what some others had alluded to before.

Appreciate your posts here.

Thanks Ross, I appreciate your and everyone's interest in the topic. I don't blame anyone for being jaded, given the number of times you have been led along and disappointed. But progress is being made, and we are learning from other's failures. If this was easy, it would have been solved years ago. Rome wasn't built in a day...
 

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https://www.avweb.com/ownership/what-if-they-had-a-pafi-and-no-one-came/

IMO, the people in the agency pushing the very challenging project get paid whether they complete the work or not. Guess where that goes.

PAFI funding was severely curtailed in 2018 after the first iteration failed to produce a viable drop-in fuel. The AIR 600 office then opened up the field to other fuel offerors. Several stepped forward. Two are still in the game, to my knowledge.

So the FAA PAFI folks and contractors supporting them all have skin in the game. I have seen their dedication to finding a solution first hand. Could they find another job in the agency, probably. Could the contractors, maybe. Do they care about the program and finding a solution, most definitely.
 
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What's the relationship between the lead and the octane increase?

Linear, exponential, log something else?

What happens if you just decrease the lead in 100LL?

You lose detonation resistance, but not linearly. The decrease is steep and non-linear. Not sure how to describe it mathematically. What is clear is that 100LL minimum specs are borderline acceptable in turbos. Fortunately, most FBOs and fuel suppliers are well above min-spec 100LL.

Ultimately,the detonation resistance of the base fuel determines how low you can go.
 
I am not getting what engines George is talking about when he refers to air cooled race engines, TBOs and unleaded avgas?

I assume race refers to stuff at Reno. Most of the turbo stuff in Sport class has a TBO of less than 20 hours and some less than 20 minutes. I fail to see how UL avgas affects how long these last before teardowns and has anyone run their fuel in these engines under race conditions?

Maybe I'm missing something here...:confused:
 
Podcast

The podcast makes it seem like a Goldilocks moment in this quest. Is his unleaded fuel really that good? I would really like to not have the lead sludge build up, and be able to use synthetic oils. Mobil 1 in cars seems to allow virtually no wear, wouldnt that be sweet.
 
I am not getting what engines George is talking about when he refers to air cooled race engines, TBOs and unleaded avgas?

I assume race refers to stuff at Reno. Most of the turbo stuff in Sport class has a TBO of less than 20 hours and some less than 20 minutes. I fail to see how UL avgas affects how long these last before teardowns and has anyone run their fuel in these engines under race conditions?

Maybe I'm missing something here...:confused:

I assumed a lot of Reno engines consumed non-aviation specific high octane jungle juice. Some of that stuff is 120+ octane. Unleaded is a little bit less, but all are well over 100 octane. When an 50+ grand engine lasts 20 hours, $20/gal fuel isn't even noticed.

Do Reno rules specify allowable fuels?

Executive Summary is FAA provided a lot of scrutiny with fuel development. They're working on distribution. Yes it does require an STC, and FAA is being surprisingly helpful in STC distribution. Still some STC distribution stuff to go, but future looks hopeful. STC is required because it's "too heavy" as compared to 100LL. 6.3#/gal instead of 5.9#/gal. Energy density is proportionally higher, so pound for pound, the G100UL offers the same range. Since it is more dense and more fuel weight fits in the same tanks, the extra weight actually provides slightly greater range.
 
I assumed a lot of Reno engines consumed non-aviation specific high octane jungle juice. Some of that stuff is 120+ octane. Unleaded is a little bit less, but all are well over 100 octane. When an 50+ grand engine lasts 20 hours, $20/gal fuel isn't even noticed.

Do Reno rules specify allowable fuels?

Many are using VP or similar leaded race fuels, several still 100LL though. Most forced induction stuff runs ADI to avoid detonation.
 
I think the new approvals are for aircraft types. For our RVs, all the Lycoming parallel valve engines are approved for using 91 octane premium non-alcohol auto gas a while ago. This is applicable your 0-360-A1A and my IO-360-1MB engines.
 
Is the 94UL cheaper than 100LL?

Carl


Currently $0.20 per gallon more than 100LL. The airports involved are choosing to price it close to 100LL to encourage those who can switch to do so.

From what I've learned about 94UL, it is actually cheaper to produce than 100LL. That is because 94UL is the same hydrocarbon mix as 100LL, minus the lead compound. What increases the cost for those of us on the west coast is shipping from the Swift Fuels Indiana refinery. With flight schools at SQL and RHV using 94UL in their trainer fleet, there is now enough demand here to ship by rail car.

Maybe it gets cheaper the closer you get to Indiana? :)

Pointer to upcoming SQL flight school webinar (November 6) on using 94UL in their fleet:
https://www.faasafety.gov/SPANS/event_details.aspx?eid=108615
 
SNIP
However to the OP topic. That is great if we can get an Aviation fuel that provides great 100 octane detonation margins, great lubricity, and low volatile, with vapor pressure under 7 psi (vs automotive gasoline 8 to 14 psi). Great!!! :D

But at a price that we can afford, as in less than the current 100LL price. All indications are this wonder fuel will be at least $1 over 100LL, and I’d guess it will be a lot higher than that if/when it is mandated. Swift 94 can be had for less than 100LL but only if we can get some FBOs to take a chance and provide it. Not everyone can use 94UL, but not all FBOs need to carry it - just like only a few FBOs carry MOgas.

Carl
 
Direct injection on my Chevrolet truck standard engine (11.5 to 1 pistons) lets me burns 87 octane pump gas. Why can’t Lycoming do the same?
I saw a paper that explained that large diameter cylinders (like our 5+ inch ones) don't perform well with direct injection. Too much charge stratification? Or not enough?

Paul
 
Bringing back an old one

It's been all over aviation news lately, in general. It would appear the Swift ball is still rolling. Rather than cut/paste/repeat things here, I'll post a link instead:

https://www.swiftfuelsavgas.com/faq

The 100 octane stuff is about 1/2 way down. I'm really hoping this works out. The "We've got you!" attitude I perceived from GAMI and their reported lack of testing transparency was a concern for me. I really want to keep my 9.6:1s in my virgin engine. The commingle-ability with 100LL and associated systems is a bigger deal than most would imagine; easing a lot of the logistics burden.

Another good thread is here:

https://vansairforce.net/community/showthread.php?t=202016&highlight=PAFI

Yes. Still plenty of questions to be answered and not pushing a debate between proposed potential offerings. The new solution approach of a three segment working partnership versus churning inside of a gov't program can only help, IMO.
 
... I'm glad there's still more than one company in the game. That can only help us.

https://www.aopa.org/news-and-media...rustration?utm_source=ebrief&utm_medium=email

Indeed. Hopefully this problem will be solved in the coming months/years. I'm happily burning unleaded UL91 and unleaded mogas in my 8.5:1 180hp io-360, and only use 100LL when I'm traveling.

I get the feeling that something about the G100UL offering is rubbing some people the wrong way, but I have no idea what it is. Seems like the FAA is not cooperating, and the other 3 and 4 letter orgs also seem to be less than enthusiastic. I tried to understand this in discussions at the GAMI booth in Oshkosh, but didn't learn anything new.

Now that GAMI has proven that a formulation can work, I'm sure that there will be others doing the same.
 
Most have probably seen this. My only comment is I'm glad there's still more than one company in the game. That can only help us.

https://www.aopa.org/news-and-media...rustration?utm_source=ebrief&utm_medium=email

I find that all the talking around the subject GAMMI fuel and all the subterfuge in your various comments make it hard for me to know what problems you are having with its fuel. I love to know if there are downsides to its fuel but it's tough to find them in your posts. Okay so you have issues with turbo. Most RVs don't have turbos. So what are the downsides to all the RVs that have the factory 8.5 compression ratio engines
 
Mogas

So what are the downsides to all the RVs that have the factory 8.5 compression ratio engines

Run non-ethanol unleaded per the Lycoming STC guidance, even though we don’t need an STC for experimental aircraft, with the 8.5:1 compression. Some day a politically correct fuel will emerge at our airports.

Until then save $ and worry less. I’m looking forward to 100UL, but am not holding my breath.
 
I find that all the talking around the subject GAMMI fuel and all the subterfuge in your various comments make it hard for me to know what problems you are having with its fuel. I love to know if there are downsides to its fuel but it's tough to find them in your posts. Okay so you have issues with turbo. Most RVs don't have turbos. So what are the downsides to all the RVs that have the factory 8.5 compression ratio engines

Flyintiger was mostly right IMO, for whatever that matters.

1) Is your airframe is configured for Mogas?

2) Do you only fly and fuel at your home airport where you have your own stash of fuel?

If both answers are yes, you'll probably have no interest in 100LL replacement. If you don't know the answer to 1) or even have to ask you're potentially flirting with disaster. Lots of text and threads on the subject.
 
It is interesting that in the January--March timeframe, the GAMI folks were speaking very highly of the involvement of the FAA, even the "bureaucrats" in Washington were keeping up their end of the work-load, completing an extensive audit of all the test data and processes up to that point. The GAMI folks were very optimistic that the FAA would sign off on the fleetwide STC by March, as was apparently agreed to. That that has not happened yet is pretty disappointing. Still hoping it is "just around the corner".
 
Get out of the way

So the EPA said we should remove the lead from avgas. This company (GAMA) did that. And got approval from the FAA through the STC process.

What is the hold up?

Was the wrong person the smartest guy in the room?
Is the govt waiting for their preferred supplier to come up with one?

Seems to me the govt needs to get out of the way, and let it succeed or crash and burn ( ok bad pun) on its market merits.

Does the FAA really want congress to mandate a replacement fuel in its next faa reauthorization? Is that what it is going to come down too?
 
The heat is being turned up recently it seems on the FAA with these hearings. I may be wrong but wouldn't the EPA start pushing for answers too here pretty quick after putting this is motion so many years ago and with the recent moves in California to start the move away from 100LL?

Something just doesn't seem right here. Is the FAA waiting for Swift and LyondellBasell to finish up their entries before they decide who wins or will all 3 companies be able to market their formulations?
 
The heat is being turned up recently it seems on the FAA with these hearings. I may be wrong but wouldn't the EPA start pushing for answers too here pretty quick after putting this is motion so many years ago and with the recent moves in California to start the move away from 100LL?

Something just doesn't seem right here. Is the FAA waiting for Swift and LyondellBasell to finish up their entries before they decide who wins or will all 3 companies be able to market their formulations?

Very unclear, and people wonder why there is public distrust in government - they need to be more transparent about their processes. We're only seeing one side of the story, but GAMI makes a pretty good case that they are not being treated fairly.

There are some problems that seem to require the government step in, and clearly this is one. The gov't needs to step in (Congress, EPA) and get out of the way (FAA).
 
When my son was younger he would ask some very good questions, and my typical answer was things happen because of money. Follow the money, and someone with a LOT of money does not want GAMI G100UL to go to market. According to GAMI all that is required is a signature from FAA Wichita.

I for one am pretty pissed off, I don’t want lead in my engine.

I have tried to dig deep into who is behind the delay.

I can come up with two likely choices

1) The Scottish company (only one in the world) who produces the lead in AVGAS

2) Phillips

Take your pick or make your own guess
 
There’s only one factory in the world that makes TEL for AVGAS and it’s in Ellesmere Port, Liverpool.

The company is American, based in Colorado. Innospec.

https://innospec.com/fuel-additives/transportation/octane/

Nope, as of 2 years ago, there are at least 3 in China but I don't think US fuel vendors are buying from there.

https://www.avweb.com/insider/the-tel-scare-that-wasnt/

Yi Shui He Fuel Additives Co Ltd. located in Qingdao is still marketing it today for instance. There is another company in Liaoning province making it at this time too.

https://lead.org.au/TEL_for_MOGAS_manufacture_in_China_20130816.pdf

China has a rather large piston primary training fleet for airline pilots, much of it located in Chengdu. They actively manufacture their own leaded avgas to slightly different specs from the west. (higher TEL content)

Been to these areas myself several times 2012-2015. Quite fascinating to learn about their aviation infrastructure.
 
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Nope, as of 2 years ago, there are at least 3 in China but I don't think US fuel vendors are buying from there.

https://www.avweb.com/insider/the-tel-scare-that-wasnt/

Yi Shui He Fuel Additives Co Ltd. located in Qingdao is still marketing it today for instance. There is another company in Liaoning province making it at this time to.

https://lead.org.au/TEL_for_MOGAS_manufacture_in_China_20130816.pdf

China has a rather large piston training fleet for airline pilots, much of it located in Chengdu. They actively manufacture their own leaded avgas to slightly different specs from the west. (higher TEL content)


There you go, no problem.

Just import Avgas from China.
 
There you go, no problem.

Just import Avgas from China.

Not practical nor suggesting that, just offering that Innospec isn't the only manufacturer of TEL for avgas as you asserted.

The west already imports lots of stuff from China, TEL could be obtained as well but in any case, Innospec has said they have no intention of stopping production while there is still a demand.

I'm a proponent of unleaded avgas and would like to see TEL gone ASAP.
 
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