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

[mluvara]

Here's the background as I know it and have come to learn the history of over the past couple months.

- In ~2011, CEH (Center for Environmental Health) sued several distributors of fuel (flight schools, FBO's,etc) regarding California's Prop 65 (we all know as the 'everything may cause cancer, harm, etc' labeling). 
- In 2014, a settlement (consent agreement) was made by the parties to carry unleaded when it came available

fast forward....

CEH sued in Dec 2024 to enforce settlement agreement... and make them carry the 'commercially available' G100UL.
See Avweb for summary of the court documents

Not only that, they added a request to modify the agreement and prematurely ban 100LL in California before the FAA 2031 deadline.

Given some recent filings requested use of my photos and referenced my work, I purchased a few documents. They are public record and free to share once purchased, so I am offering them here. If you want the rest, the docket location was posted earlier in this thread.

A set of filings the past week describe several G100UL user's experiences (not all of them that exist). Grab your favorite drink and have a read... I've tried to put them in general chronological order.

59816247_01_24_2025_Declaration_OF_GEORGE_W__BRALY_IN_SUPPORT_OF_PLAINTIF___

59816248_01_24_2025_Declaration_OF_PAUL_MILLNER_ON_BEHALF_OF_THE_AIRCRAFT___

59909915_02_18_2025_Ex_Parte_Application_Settling_Defendants_Ex_Parte_App___

59909917_02_18_2025_Declaration_Of_Patrick_Davis_In_Support_Of_Defendants___

59909918_02_18_2025_Declaration_Of_David_Bertucci_In_Support_Of_Defendant___

59909919_02_18_2025_Declaration_Of_Sean_Patrick_Kelley_In_Support_Of_Defe___

59909920_02_18_2025_Declaration_Of_Daniel_Demeo_In_Support_Of_Defendants____

59909921_02_18_2025_Declaration_Of_Steven_E__Rubin_In_Support_Of_Defendan___

59909922_02_18_2025_Declaration_Of_Bruce_T__Nelson_In_Support_Of_Defendan___

59909923_02_18_2025_Declaration_Supplemental_Declaration_Of_Patrick_Waddi___

59909924_02_18_2025_Declaration_Of_Jeffrey_Soule_In_Support_Of_Defendants___

59913858_02_20_2025_Declaration_SUPPLEMENTAL_DECLARATION_OF_PAUL_MILLNER____

Edited yesterday at 05:09 AM by mluvara

[MikeOH]

What the heck is this Aircraft Pilots of the Bay Area (APBA), and who is their president, Paul Millner???  Reading his last 'Declaration' makes my blood boil.  The dude went out to the airport looked at planes leaking and basically supports Braly and enforcing the consent decree!

Good grief!  Pilots out actively trying to ban 100LL??

[shawnd]

Gets your blood boiling is an understatement. I am wondering if these guys have financial interests in GAMI succeeding as his comments really doesn’t make much sense otherwise. A streak of blue in the past versus large swath of recent G100UL leaks. Oh it’s a Mooney and the tanks were patched, must be bad. I have had my tanks patched and  they hold 100LL just fine.   I  at a loss of words with these statements. 

[redbaron1982]

What boils my blood the most is having fellow Mooney owners siding with George Braly.

[Marc_B]

On 12/31/2024 at 5:06 PM, George Braly said:

Mike,  to answer your question,  the answer is "no" - - I do not advocate a ban on 100LL before there is another high octane avgas approved to be used in place of 100LL on all of the high performance engines and related airplanes - - and is also available. 

Read "quotes" with deference.  Looking back, there's been a lot of them added in his posts. The only thing required is "approval" and ban is fair game.  But what happens when "approved" doesn't mean safe???

[EricJ]

2 hours ago, redbaron1982 said:

What boils my blood the most is having fellow Mooney owners siding with George Braly.

That has puzzled me for a long time.

[Pinecone]

17 hours ago, A64Pilot said:

ADI wise.

Failure is or could be easily made to be extraordinarily unlikely, the injection plate is just that, no moving parts with several injection holes. Then there are two pumps and surely both are tested on run-up, Separate electrical systems is as easy as a battery back-up like several current instruments. Have a pressure switch like one that runs many hobbs meters will tell you it’s on via a light, and or a failure light is dead easy, heck add a horn if you think it necessary, if the electronics fail it fails to the on position, or you have a switch that merely turns the power on, it’s not modulated it’s just on or off.

But what happens if it DOES fail on take off?

And remember, these will be maintained by the same mechanics that have "patched" leaking fuel tanks with RTV.

[bonal]

I looked up APBA’s website and it’s in my opinion very questionable if it’s a legitimate pilot association.  They list their mission and provide an email address for joining and to receive information about events. It mentions other area fields that have members.  These east bay airports have lots of planes based there and one would think that with so many people literally thousands if you add them up there would be a lot more information about this association.  A few photos that don’t show much no list of administrators or photos of past events etc. we have all visited associations websites and you can clearly see a big difference. Now there is no requirement that a website has to be extensive and professional in appearance. I just wonder if this guy supporting the plaintiff is even a pilot.  Of course it’s just an opinion based on a single observation and I could be mistaken.  
 

If I had to choose I would much rather use UL94 than this not thoroughly tested fuel.  I have never seen UL94 don’t know where it’s being sold but my o360 is ok with it.  I also read on Avweb that Piper has basically said the G100 is not approved for any of its fleet.  I read all the depositions and based on Californias politics and how they love to regulate everything to death I would be shocked if the judgment would side with the defendant.  This literally could be the end of GA piston aviation in our communist state. Unless G100UL works out.

[Sabremech]

Did anyone else notice the 45% or 25,000 Mooney aircraft comment in George’s statements? Just a little bit off on the number of Mooney’s ever built. 

[redbaron1982]

In case anyone is interested, I'm sending this letter to AOPA. I guess if enough people write to them, it could help push them to take a more active role here:

"

[Your Name]
[Your Address]
[City, State, ZIP Code]
[Email Address]
[Phone Number]
[AOPA Member ID]
[Date]

Aircraft Owners and Pilots Association (AOPA)
421 Aviation Way
Frederick, MD 21701

Dear AOPA Leadership,

I am writing to express my deep concern regarding the ongoing debate over the use of 100LL aviation fuel in California. As a dedicated member of AOPA, I have always valued the association's commitment to advocating for the interests of pilots and aircraft owners. However, I am increasingly disheartened by AOPA's lack of a strong public stance against the ban on 100LL fuel in California.

The recent push to replace 100LL with G100UL has raised significant concerns within the aviation community, particularly regarding material compatibility. Reports indicate that G100UL may cause structural damage to aircraft components, including paint degradation, seal degradation, and fuel leakage. These issues pose serious airworthiness concerns and could compromise the safety of our aircraft.

While we are all on board with the transition to unleaded (UL) fuel, it is crucial that this transition is carried out in a reasonable manner that does not introduce airworthiness risks. The aviation community relies on AOPA to be a vocal advocate for our interests, and your silence on this matter is both troubling and unacceptable.

Given these material compatibility concerns, it is imperative that AOPA takes a definitive stand against the premature banning of 100LL fuel. If AOPA does not publicly oppose the ban on 100LL fuel and advocate for a more measured approach that ensures the safety and reliability of alternative fuels, I will be left with no choice but to cancel my membership. I urge AOPA to step up and fulfill its role as a leader in the aviation community by addressing this critical issue.

Thank you for your attention to this matter. I look forward to seeing AOPA take a strong and proactive stance in support of our community.

Sincerely,

[Your Name]"

Edited 14 hours ago by redbaron1982

[MikeOH]

I have received several DMs indicating that Paul Millner is a petroleum engineer that helped Braly develop G100UL.  I have NO idea if this is true; I have not verified that in any way.

If true, however, it would explain his court declaration.  I would hope the court (i.e. the judge) is aware of his position, but maybe not

[Marc_B]

"One option that GAMI has asked the FAA to consider is to simplify the STC implementation process for aircraft owners planning to use G100UL (or presumably any other STCed unleaded avgas). GAMI envisions a methodology by which an aircraft owner, even standing in an FBO lobby, could purchase the STC and electronically record the FAA Form 337 approval of that STC with the FAA for their engine and airframe without intervention by an airframe and powerplant mechanic with inspection authorization as is normally required. The technical competence to install the required placards should be well within owner maintenance abilities. The FBO might source the placards, or GAMI could mail them. The FAA seems intrigued by this simplification of the process for unleaded avgas implementation, but the bureaucratic process can be slow." —Paul Millner

 

Find it interesting that the original thought communicated was that there was NO need for A&P input, evaluation of your airframe, or determination if G100UL is safe for use.  But now comments from Braly/GAMI read that there are aging issues, defunct maintenance techniques, and poor aircraft design issues that AREN'T considered with their STC AML that an owner will need to review closer to make sure their airframe is safe for G100UL use.

Edited 13 hours ago by Marc_B
added link

[mluvara]

21 minutes ago, redbaron1982 said:

In case anyone is interested, I'm sending this letter to AOPA. I guess if enough people write to them, it could help push them to take a more active role here:

"

[Your Name]
[Your Address]
[City, State, ZIP Code]
[Email Address]
[Phone Number]
[AOPA Member ID]
[Date]

Aircraft Owners and Pilots Association (AOPA)
421 Aviation Way
Frederick, MD 21701

Dear AOPA Leadership,

I am writing to express my deep concern regarding the ongoing debate over the use of 100LL aviation fuel in California. As a dedicated member of AOPA, I have always valued the association's commitment to advocating for the interests of pilots and aircraft owners. However, I am increasingly disheartened by AOPA's lack of a strong public stance against the ban on 100LL fuel in California.

The recent push to replace 100LL with G100UL has raised significant concerns within the aviation community, particularly regarding material compatibility. Reports indicate that G100UL may cause structural damage to aircraft components, including paint degradation, seal degradation, and fuel leakage. These issues pose serious airworthiness concerns and could compromise the safety of our aircraft.

While we are all on board with the transition to unleaded (UL) fuel, it is crucial that this transition is carried out in a reasonable manner that does not introduce airworthiness risks. The aviation community relies on AOPA to be a vocal advocate for our interests, and your silence on this matter is both troubling and unacceptable.

Given these material compatibility concerns, it is imperative that AOPA takes a definitive stand against the premature banning of 100LL fuel. If AOPA does not publicly oppose the ban on 100LL fuel and advocate for a more measured approach that ensures the safety and reliability of alternative fuels, I will be left with no choice but to cancel my membership. I urge AOPA to step up and fulfill its role as a leader in the aviation community by addressing this critical issue.

Thank you for your attention to this matter. I look forward to seeing AOPA take a strong and proactive stance in support of our community.

Sincerely,

[Your Name]"

AOPA has supported a safe and smart transition to unleaded fuels, including the filing of a part 16 complaint opposing Santa Clara County's unilateral ban on 100LL that started this whole mess. 

You can see much of that history here. https://www.aopa.org/advocacy/100-unleaded-avgas

https://www.aopa.org/news-and-media/all-news/2024/november/26/aopa-asks-faa-to-rule-against-california-county-avgas-ban

Edited 13 hours ago by mluvara

[bonal]

6 minutes ago, Marc_B said:

"One option that GAMI has asked the FAA to consider is to simplify the STC implementation process for aircraft owners planning to use G100UL (or presumably any other STCed unleaded avgas). GAMI envisions a methodology by which an aircraft owner, even standing in an FBO lobby, could purchase the STC and electronically record the FAA Form 337 approval of that STC with the FAA for their engine and airframe without intervention by an airframe and powerplant mechanic with inspection authorization as is normally required. The technical competence to install the required placards should be well within owner maintenance abilities. The FBO might source the placards, or GAMI could mail them. The FAA seems intrigued by this simplification of the process for unleaded avgas implementation, but the bureaucratic process can be slow." —Paul Millner

So are you PaulMillner or are you just posting a letter he signed.  I’m pretty confident that most of us aren’t upset about the STC but rather that there may be real concerns about the fuel going into our aircraft.  Not too excited about being forced into using a fuel that could ruin my airplane.  Is there a list showing where UL94 is available.  If the ban goes into effect I will petition as many suppliers to start providing the 94.

[aviatoreb]

Only a bit related - but with UL94 also being discussed - wasnt there an effort at some point to make some kind of electronics timing modifications to the big TSIO engines so that even they can use UL94 safely?  I know the push toward a drop in replacement has merits but I dont understand why reasonable mods with modern electronics might also get us to a useful point if most engines can be lightly modded to accept a different kind of easy to use and lead free like UL94?

[Andy95W]

2 hours ago, Pinecone said:

But what happens if it DOES fail on take off?

And remember, these will be maintained by the same mechanics that have "patched" leaking fuel tanks with RTV.

Yes, an ADI failure on takeoff is possible.  You’d get a warning light, reduce throttle if possible, and land.

What if you have a fuel injector partially clog on takeoff?  What if your pressure controller fails and your relief valve fails?  What if your fuel injection unit fails at a lean mixture?  What if you break a crankshaft or a connecting rod?

No matter which, you’re still gonna wish you were back in an A10.

[Andy95W]

6 hours ago, redbaron1982 said:

What boils my blood the most is having fellow Mooney owners siding with George Braly.

 

3 hours ago, EricJ said:

That has puzzled me for a long time.

I can maybe answer part of that (and for the record, I never “sided” with George Braly).

I really wanted G100UL to succeed.  I was hopeful that a viable, unleaded alternative existed and that it truly was a drop in replacement. I was looking forward to longer oil change intervals and not having to clean spark plugs as much.  And it looked like the price was going to be reasonable.

The only information we had to go on was GAMI’s test data and the AOPA Baron experiment, both of which looked promising- until now.

I wouldn’t mind a bit of paint staining.  But I won’t sign up to reseal my tanks or want to listen to Braly’s tap dance saying that a wet-wing fuel tank is somehow inadequate just because his fuel eats the sealant. 

Edited 12 hours ago by Andy95W

[A64Pilot]

3 hours ago, Pinecone said:

But what happens if it DOES fail on take off?

And remember, these will be maintained by the same mechanics that have "patched" leaking fuel tanks with RTV.

You flip the manual switch on or reduce power, but I wouldn’t be surprised knowing Rob Roberts that the pump switch over wouldn’t be automatic, with an annunciation that the primary has failed.

Arguing what if is non sensical, there are literally several components that if they failed result in immediate engine failure.

The safest response is always don’t fly. 

But your missing the point, assuming the pronoun people take away our lead, what’s your answer?

From what I can tell ADI is pretty much the only answer, unless you have one?

[A64Pilot]

40 minutes ago, aviatoreb said:

Only a bit related - but with UL94 also being discussed - wasnt there an effort at some point to make some kind of electronics timing modifications to the big TSIO engines so that even they can use UL94 safely?  I know the push toward a drop in replacement has merits but I dont understand why reasonable mods with modern electronics might also get us to a useful point if most engines can be lightly modded to accept a different kind of easy to use and lead free like UL94?

It could be done relatively easily, essentially your just reducing power, but implementation would be a Bitch, beside Certification of the hardware and God forbid if there is Software involved, but every different Model of Aircraft woukd have to be throughly Test Flown and most every chart rewritten in the POH and likely pretty significant reductions in gross weight due to not meeting required climb gradients at lower power etc.

Be BIG bucks by the time it was done, Then there is a more sophisticated system possible involving knock sensors etc that would only reduce power as necessary, but as you would have to worst case power reductions with charts and Gross Weight etc I don’t know what you would gain, but I’m sure it would cost even more $$$, and as power output would vary with conditions I’m not sure the FAA would buy off on it.

Certification has a way of making easy and simple HARD, but when done correctly you don’t get surprises

I think your question is very related myself, any way to get us an unleaded fuel is I think worth looking into, maybe we couldn’t Certify it, but someone could.

Edited 13 hours ago by A64Pilot

[redbaron1982]

48 minutes ago, mluvara said:

AOPA has supported a safe and smart transition to unleaded fuels, including the filing of a part 16 complaint opposing Santa Clara County's unilateral ban on 100LL that started this whole mess. 

You can see much of that history here. https://www.aopa.org/advocacy/100-unleaded-avgas

https://www.aopa.org/news-and-media/all-news/2024/november/26/aopa-asks-faa-to-rule-against-california-county-avgas-ban

In my opinion they should be stronger on pushing back here.

[gabez]

4 minutes ago, redbaron1982 said:

In my opinion they should be stronger on pushing back here.

I emailed the AOPA twice. both times they gave me a very soft answer...they don't give a crock. I also emailed 2 times the WPA and they didn't bother to respond either. 

[redbaron1982]

30 minutes ago, Andy95W said:

I really wanted G100UL to succeed.  I was hopeful that a viable, unleaded alternative existed and that it truly was a drop in replacement. I was looking forward to longer oil change intervals and not having to clean spark plugs as much.  And it looked like the price was going to be reasonable.

I think we are all on the same page here. At least, I was super excited about G100UL.

But I don't want to repaint my airplane with G100UL-compatible paint and/or reseal my tanks or install a bladder.

[A64Pilot]

14 minutes ago, redbaron1982 said:

or install a bladder.

Most bladders, Mooney ones anyway are made out of Nitrile, that’s the stuff the O-rings that the G100UL swells up. Mine are. 

Biggest issue I see is that I bet Lunch that anything that eats up fuel tank sealer in a week or two, will eat up pretty much anything given enough time, Bladders, fuel lines, pump seals etc.

Fuel tank sealer once cured is impervious to almost anything, that’s why it can hold different kinds of fuel and fuel additives etc.

What has not been addressed so far as I know is what’s the health effects of exposure to the components of G100UL?

I know what Acetone, MEK and several other petroleum based solvents is, but what about what’s in G100UL?

I’d bet Lunch that some of those chemicals have health effects that are worse than the lead in 100LL, but apparently as long as it gets rid of lead, brews of Carcinogens is OK?  

[shawnd]

2 hours ago, redbaron1982 said:

In case anyone is interested, I'm sending this letter to AOPA. I guess if enough people write to them, it could help push them to take a more active role here:

I think we should probably figure out how to get this to our governors and local legislators as well? Not sure how/who can coordinate...typically AOPA sends out these comms.

[A64Pilot]

Having worked directly with the FAA ACO, MIDO etc. I can attest that organizations like AOPA really do have their ear and they do pay attention to them.

What surprised me s little is that Type clubs , like the Bonanza Assn etc have a strong voice as well. So sure call or write your Congressman etc., but my take was you may get more traction with voicing your concerns with AOPA, with I think the emphasis being airworthiness concerns over paint staining.

Just my opinion, but the FAA reacts to complaints, I’ve seen it and had to respond to the FAA ref them on occasion.