Based on the G100UL fuel leak thread what's your position?

[Aaviationist]

  On 3/31/2025 at 8:53 PM, varlajo said:

Totally agree. It's like "Hey y'all, anyone having issues with 20W50XC? Let us know!" 

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That’s literally what it is. 
 

yes Mike, that seems to be exactly what this is. 
 

It’s a nothing sandwich. A document with a header, and a footer, containing nothing. 
 

 

[A64Pilot]

I think it IS something, for example they didn’t issue one for 20W50XC.

PLEASE, anyone who has had difficulty with this fuel fill out the forms, they NEED complaints, that’s what drives the FAA, without complaints or accidents there is no problem

[Marc_B]

https://www.avweb.com/aviation-news/snf-podcast-g100ul-update/
 

Anyone gonna be out at Sun N Fun tomorrow for Braly’s presentation?  The link above had a brief interview with Braly.

[gabez]

  On 4/2/2025 at 4:48 AM, Marc_B said:

https://www.avweb.com/aviation-news/snf-podcast-g100ul-update/
 

Anyone gonna be out at Sun N Fun tomorrow for Braly’s presentation?  The link above had a brief interview with Braly.

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oof didn't address the stains, the paint peeling and the latest write up from Paul.....19 minutes of nothing

[Echo]

  On 4/2/2025 at 12:28 PM, gabez said:

oof didn't address the stains, the paint peeling and the latest write up from Paul.....19 minutes of nothing

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What?  Braly DID discuss the leaks n Mooney's.  He waxed on about how he used to fly a 1967 Mooney.  Paraphrasing he said:

-Mooneys and some Cessna aircraft had shoddy sealant installs that were completed 30, 40, 50 years ago. 

-Is it possible that when a tank is leking that my gas is more aggressive on sealant?  Yes.

-It is only Mooney's and some Cessnas so not a big deal because there are so many benefits to the fuel.  TBO, Etc...

-The percentage of planes having issues is small and 100ll use resulted in leaks as well

- He specifically called out Weep No More and said there are three other aluminum integral tank sealant operationsin business.  (insinuating that tanks leaked and needed repair with 100ll.  It is a known problem so not our problem)

My take-away.  He knows his fuel is more aggressive on tank sealant, but hey no fuel is perfect so buck up, your plane is old.  Deal with it.

[Pinecone]

  On 3/31/2025 at 11:12 PM, A64Pilot said:

I think it IS something, for example they didn’t issue one for 20W50XC.

PLEASE, anyone who has had difficulty with this fuel fill out the forms, they NEED complaints, that’s what drives the FAA, without complaints or accidents there is no problem

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And people WITHOUT any issues need to report that also.

They need complete data, not one-sided.

[A64Pilot]

  On 4/2/2025 at 2:24 PM, Pinecone said:

And people WITHOUT any issues need to report that also.

They need complete data, not one-sided.

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If the FAA has any sense and I believe they do, then they know how many aircraft have used it, and face it only people with problems will report, so no report? No problem is a safe assumption.

That is why I think anyone with problems should report, because if they don’t then the assumption is they didn’t have problems.

But sure report no problems if you want to, can’t hurt. Data is data.

My belief is this fuel aggressively attacks “rubber” paint etc., that’s in my opinion been proven beyond a reasonable doubt, and I believe given enough time it will cause many more failures of those components, it’s getting the weakest first is a pretty safe bet, but given enough time the percentage of problems will increase.

Even if it “only” reduces the average life expectancy of new tank seal job by half, is that to be considered acceptable?

How much degradation is acceptable? We know it swells common O-rings well beyond the FAA acceptable limit already, that should have been enough to not issue an STC in my opinion.

Then the paint issues are apparently real too, and no level of refueling hygiene is going to keep it from staining and apparently destroying paint around the vents etc. Maybe it would be acceptable to only fill tanks half way if you’re burning the G100UL? That ought to prevent vent staining / deterioration?

But the real Damning thing in my opinion is Cirrus saying that they are concerned that this fuel destroys their wings structural integrity, now to be fair I don’t think that’s what they said, they only said they had concerns about the airworthiness of their aircraft that had used this fuel. For Cirrus to come out and say that is huge in my opinion, because they are no Dummy’s, they know that any statement like that they had better be prepared to defend it in a court of law.

Of course this is my opinion, and we all know what our individual opinions are worth.

[N201MKTurbo]

I attended a session by the FAA about unleaded fuels at the Maintenance Symposium a few weeks ago. At the end, the FAA man says that people are always asking when there will be a drop in replacement for 100LL. he said “never” 

[A64Pilot]

  On 4/2/2025 at 3:52 PM, N201MKTurbo said:

I attended a session by the FAA about unleaded fuels at the Maintenance Symposium a few weeks ago. At the end, the FAA man says that people are always asking when there will be a drop in replacement for 100LL. he said “never” 

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I just read that Shell will be shipping 100VLL in Europe soon, I assume it’s even lower lead than LL, is an ASTM fuel apparently. I know nothing about it.

I’ve come to believe that it’s not achievable either, or it would have been done by now. I’d bet lunch that this G100UL fuels health risks are greater than the lead in 100LL, but that’s just a belief.

Way I see it is there is only two paths forward if lead must go, either a yet to exist new engine, or ADI for those that must have 100 Aviation Octane. Well three I guess we could just scrap our airplanes.

I can’t afford a yet to exist engine and don’t want ADI, but if lead must go, ADI is all I could afford

My bet is a new water cooled four valve engine could meet the HP requirements on Premium car gas, but it’s vaporware at this point and I don’t expect to see one either

Edited Wednesday at 04:07 PM by A64Pilot

[N201MKTurbo]

  On 4/2/2025 at 3:57 PM, A64Pilot said:

I just read that Shell will be shipping 100VLL in Europe soon, I assume it’s even lower lead than LL, is an ASTM fuel apparently. I know nothing about it.

I’ve come to believe that it’s not achievable either, or it would have been done by now. I’d bet lunch that this G100UL fuels health risks are greater than the lead in 100LL, but that’s just a belief.

Way I see it is there is only two paths forward if lead must go, either a yet to exist new engine, or ADI for those that must have 100 Aviation Octane. Well three I guess we could just scrap our airplanes.

I can’t afford a yet to exist engine and don’t want ADI, but if lead must go, ADI is all I could afford

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Or MP limitations with updated performance charts. That’s what warbirds that were built for 145 octane fuel do when burning 100LL they just limit MP.

[gabez]

  On 4/2/2025 at 2:23 PM, Echo said:

What?  Braly DID discuss the leaks n Mooney's.  He waxed on about how he used to fly a 1967 Mooney.  Paraphrasing he said:

-Mooneys and some Cessna aircraft had shoddy sealant installs that were completed 30, 40, 50 years ago. 

-Is it possible that when a tank is leking that my gas is more aggressive on sealant?  Yes.

-It is only Mooney's and some Cessnas so not a big deal because there are so many benefits to the fuel.  TBO, Etc...

-The percentage of planes having issues is small and 100ll use resulted in leaks as well

- He specifically called out Weep No More and said there are three other aluminum integral tank sealant operationsin business.  (insinuating that tanks leaked and needed repair with 100ll.  It is a known problem so not our problem)

My take-away.  He knows his fuel is more aggressive on tank sealant, but hey no fuel is perfect so buck up, your plane is old.  Deal with it.

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The percentage of planes reporting issues it's not small. if you watch Mike's videos and count how many planes he is reporting is quite material. Second, the number of planes using the fuel is single digit at best. Both airports are selling 100 gallons fuel per week. Third, the only known pilot who is at arm length from GAMI and burned a material amount of fuel has stopped using the fuel and I believe his report it's quite informative. 

So yeah move on is easy to say, until it happens to your plane. Tho we all know it won't because you won't put G100UL in it. 

Edited Wednesday at 04:19 PM by gabez

[EricJ]

  On 4/2/2025 at 4:09 PM, N201MKTurbo said:

Or MP limitations with updated performance charts. That’s what warbirds that were built for 145 octane fuel do when burning 100LL they just limit MP.

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That'll probably drop gross weight for a lot of airplanes.   That seems unlikely to be popular with GA.    With the warbirds they can just not carry ordnance any more.

[EricJ]

  On 4/2/2025 at 3:52 PM, N201MKTurbo said:

I attended a session by the FAA about unleaded fuels at the Maintenance Symposium a few weeks ago. At the end, the FAA man says that people are always asking when there will be a drop in replacement for 100LL. he said “never” 

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I think that was the guy from Eagle fuel cells, the folks who make many of the OEM and replacement bladders.   Since they're in the middle of the materials compatibility concerns his perspective was interesting.

[mluvara]

  On 3/31/2025 at 3:25 PM, mluvara said:

I reached out to Paul and conveyed your feedback to him.

Thanks for the comments. I appreciate it. 

Michael

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Paul shared this link of an updated report based on your inputs and those who have read earlier versions and thanks everyone for the input.

https://drive.google.com/file/d/1-BAdrBUFKZNaVIoJ6sFFXuu2GG9rr1Cp/view

[MikeOH]

@mluvara

Do you know if Paul will be submitting this to the FAA in response to the SAIB?

[mluvara]

  On 4/2/2025 at 5:36 PM, MikeOH said:

@mluvara

Do you know if Paul will be submitting this to the FAA in response to the SAIB?

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He said on Beechtalk that he did submit it as part of the SAIB request.

Edited Wednesday at 07:01 PM by mluvara

[A64Pilot]

  On 4/2/2025 at 4:31 PM, EricJ said:

That'll probably drop gross weight for a lot of airplanes.   That seems unlikely to be popular with GA.    With the warbirds they can just not carry ordnance any more.

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Most probably as there is a min climb grade requirement that must be met, and that’s one of several things that can determine gross weight. It’s sort of self correcting of course because altitude reduces MP. Perhaps the charts for 5,000 DA might be close enough to be acceptable to keep from having to do a complete performance test profile.

‘I’m using 25MP from the ADI number, but think it’s very conservative, 94UL would I assume allow higher than 25 MP. Not sure what would happen with the Cyl head temp limit though because it’s probably at least as important as MP.

War birds if we are talking real Warbirds anyway have by Civilian standards an excessive power to weight ratio that combined with the fact that they were never Certified means I’m sure that they easily have enough power, but as they weren’t Certified that requirement doesn’t exist. AH-64 could climb at sea level in excess of 5,000 FPM, but I bet P-47’s, P-51’s etc without ordnance would beat that even with 100 LL. 94UL just might require engine modification maybe?

I keep using 94UL as Auto fuel has all kinds of other issues like vapor pressure, phase separation etc that 94UL shouldn’t, and I’d prefer a fit for purpose Aviation fuel myself. 

 

Edited Wednesday at 11:59 PM by A64Pilot

[gabez]

between minute 5 and 10

[EricJ]

  On 4/3/2025 at 3:20 AM, gabez said:

between minute 5 and 10

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Kurt spoke at our local IA seminar last month, as previously mentioned, and went in to a lot more detail on the effects of G100UL fuel on materials, including some slides on some rather extreme swelling of gaskets and o-rings.   He made some very significant points on issues related to that fuel while still being reasonably diplomatic.  I came away with an even less favorable view of G100UL.

[IvanP]

Interesting. Essentially repeating Braly's talking points - the issues are only occuring in old clunkers, if you have a new plane you are fine. I really loved the part about the new, more aggressive fuels presenting an "opportunity" to get the old out and put the new in (shameless plug for bladders)  . Thanks, but no thanks. My tanks were resealed few years ago and are not leaking. I have plenty of other "opportunities" to spend my $$$ elsewhere. Nevertheless., I am not taking chances with G100UL unless compelled to do so by the govt.    

[gabez]

  On 4/3/2025 at 4:14 PM, IvanP said:

Interesting. Essentially repeating Braly's talking points - the issues are only occuring in old clunkers, if you have a new plane you are fine. I really loved the part about the new, more aggressive fuels presenting an "opportunity" to get the old out and put the new in (shameless plug for bladders)  . Thanks, but no thanks. My tanks were resealed few years ago and are not leaking. I have plenty of other "opportunities" to spend my $$$ elsewhere. Nevertheless., I am not taking chances with G100UL unless compelled to do so by the govt.    

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yeah man. 100%. I passed the two videos to the thread I have with the FAA/FSDO. I wasn't kind, how are we just now finding out the fuel is more aggressive by Braly's own admission and the industry was in the known that this fuel wasn't "drop in". 

 

https://www.avweb.com/aviation-news/braly-makes-his-case-that-while-not-perfect-g100ul-is-likely-the-best-unleaded-option/

Edited Thursday at 04:25 PM by gabez

[shawnd]

While I appreciate having more sources of aviation news, Social Flight videos often come across as overly promotional. They tend to focus more on highlighting the people or companies featured rather than delivering objective news. It feels more like a coordinated ad campaign than journalism. Personally, I prefer the more balanced approach of AvWeb and Aviation Consumer.

[A64Pilot]

  On 4/3/2025 at 4:24 PM, gabez said:

yeah man. 100%. I passed the two videos to the thread I have with the FAA/FSDO. I wasn't kind, how are we just now finding out the fuel is more aggressive by Braly's own admission and the industry was in the known that this fuel wasn't "drop in". 

 

https://www.avweb.com/aviation-news/braly-makes-his-case-that-while-not-perfect-g100ul-is-likely-the-best-unleaded-option/

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Attached article is the Deny and make Counteraccusations part of “being caught”

Issue is as I see it is that unlike automobiles for example the average GA aircraft was built 50 years ago,

https://generalaviationnews.com/2019/05/27/aging-pilots-aging-airplanes/

that’s the AVERAGE. So whatever solution is adopted it needs to be applicable to a 50 yr old aircraft. Requiring the entire fuel system to be replaced is unrealistic, and I maintain that the more “aggressive” fuel will significantly shorten even new components life, replacement / reseals every 7 years isn't viable from an economics perspective. 

Edited Thursday at 04:40 PM by A64Pilot

[redbaron1982]

I just realized that the main photo on g100ul.com does not show proper refueling hygiene! What a concept, right?! I guess when they took the photo, it was not still a thing to have to protect your aircraft paint while refueling.

 

 

Edited yesterday at 03:31 AM by redbaron1982

[PT20J]

When I fuel like that, gas splashes everywhere.