G100UL - fuel leak

[Sabremech]

@George Braly,

I should not have to change a thing to use any fuel. Requiring any owner to pay that bill means your fuel isn’t right. It’s ridiculous to push more costs on to owners for something that should be plug and play. I assume G100UL is more expensive than 100LL. How much more, I don’t know since it’s not available to me in the Midwest yet. 
As it stands right now, I wouldn’t use this fuel until the engine manufacturers approve it. I have no intention of training to become a glider pilot in my Mooney. 

[Marc_B]

What material is used in the fuel sump valves?  Is it servicable or do you just replace the whole valve when it fails? i.e. F391-53S or F391-72 for Monroy...

Also the A1540 Gascolator seal kit looks like they're all nitrile. 2) MS29513-031, 1) MS29513-006, 1) 600-001-5/8, 1) MS29513-010

[PT20J]

1 hour ago, EricJ said:

And it may be, especially since it shows that it exceeds the limits discussed in the Parker manual you posted as well as the papers I posted, which all show similar limits.  A visual inspection of the swelling shown in the vid is comparable to the swelling measurement methodology described in both papers.

I still think I'll rely on the guidance from the established industry rather than a lawyer taking a first stab at being a fuel formulator, but that's just me.   

Well, to be fair, I believe that George also has a degree in aeronautical engineering and he had some subject matter experts working on the formulation.

And, I did not say that the video showing the G100UL soaked o-ring swelling wasn't valid. What I said is that the comparison with the 100LL soaked o-ring may not be meaningful because we don't know the composition of the 100LL sample. Perhaps a different 100LL sample from a different refiner would have also swelled the o-ring soaked in it similarly. No one knows because determining the composition of the 100LL sample wasn't part of the experiment. That's all I was pointing out.

We don't really know that o-ring swelling is an operational issue. I'd prefer a test with different o-rings of different materials installed in different configurations simulating actual conditions we see in our airplanes. 

But, we have another problem that there is no question about with G100UL: It damages paint. Maybe it only permanently discolors paint; maybe it strips it. But there is clearly something going on. 

[PT20J]

6 minutes ago, Marc_B said:

What material is used in the fuel sump valves?  Is it servicable or do you just replace the whole valve when it fails? i.e. F391-53S or F391-72 for Monroy...

Also the A1540 Gascolator seal kit looks like they're all nitrile. 2) MS29513-031, 1) MS29513-006, 1) 600-001-5/8, 1) MS29513-010

The OEM F391 and the Curtiss valves do not have replaceable internal o-rings and I don't know what o-rings are used. The external o-ring that seals against the wing skin is nitrile. The SAF-AIR equivalent valves have replaceable Viton o-rings according to the website.

It appears that the Gerdes gascolator uses nitrile o-rings. I don't know what material is used in the 600-001-5/8 stat-o-seal. The Airight uses Viton.

Airight 51250-9 Gascolator.pdf

[EricJ]

31 minutes ago, PT20J said:

Well, to be fair, I believe that George also has a degree in aeronautical engineering and he had some subject matter experts working on the formulation.

Yes, but imho still nowhere near the credibility and experience level of established reputable industrial players like Parker, Textron, et al.

31 minutes ago, PT20J said:

And, I did not say that the video showing the G100UL soaked o-ring swelling wasn't valid. What I said is that the comparison with the 100LL soaked o-ring may not be meaningful because we don't know the composition of the 100LL sample. Perhaps a different 100LL sample from a different refiner would have also swelled the o-ring soaked in it similarly. No one knows because determining the composition of the 100LL sample wasn't part of the experiment. That's all I was pointing out.

I'd argue a comparison with a 100LL sample taken from public distribution and a sample of G100UL taken from public distribution are valid for understanding potential differences in the fuel behaviors.   It is not a representation of what will always happen, but it is definitely a valid representation of what can happen.   In aviation this is important, especially when the first such test has the indicated results.

31 minutes ago, PT20J said:

We don't really know that o-ring swelling is an operational issue.

Except that many decades of industrial experience has established an upper limit which seems to have consensus (e.g., I've seen it in at least four separate places in the last three days).   It's the sort of thing that one ignores at their own peril.   Again, ignoring such experience is not generally the sort of thing that is expected in aviation, especially in support of an inexperienced formulator promoting their first product.

31 minutes ago, PT20J said:

I'd prefer a test with different o-rings of different materials installed in different configurations simulating actual conditions we see in our airplanes. 

There's certainly a lot of room for more testing to be done.    I'd have hoped it would have all been done before people felt pressured to put it in their airplanes.   I'd hope that there'd be a pause long enough to get such indepedent testing done before people were asked to do that again, but we'll have to see what happens.   I also hope that we don't learn lessons about it at the expense of our fellow aviators or their families.

31 minutes ago, PT20J said:

But, we have another problem that there is no question about with G100UL: It damages paint. Maybe it only permanently discolors paint; maybe it strips it. But there is clearly something going on. 

Paint and o-rings and hoses and sealant may still not be the end of the list of things that wind up being concerning about G100UL.   I wish the general fleet was not where this level of testing was being done.   IMHO none of these things should be issues with a new deployment, they definitely should not be surprises, and a formulator with a broken-record response of "nothing to see here" is not helpful.

[A64Pilot]

Most O-rings are available by size in Viton, but you may have to get them from non Aviation sources, while I agree that it’s unlikely in truth that there is a quality difference, but non aviation sources don’t maintain traceability. Aviation sources are supposed to separate by batch etc, while non aviation sources just have a box by part number, they aren’t traceable

That may all seem unnecessary but it’s one of those things that are required to have, or at least the suppliers do, if there is an accident caused by something failing and you bought it from AC Spruce for example AC Spruce can supply the birth certificate for that item to the FAA / NTSB etc.

Then as has been stated it’s tough to go against the part manual, but if the STC states that you should I think that’s justification to do so. (my opinion) 

But the work to do so as in finding the exact correct size may not be easy, unless there is a cross reference chart somewhere, if there is then that makes things easier. While not common there are a few special O-rings etc, and how do you determine if what you need is one of these “special” ones as opposed to a common part?

But, here’s one rub, I’m pretty sure that at least the Viton I have experience with has a different Durometer, as in it’s stiffer or harder if you will, does that matter? Would it require a higher torque to completely seat? Above my pay grade, I don’t know, then it’s tough to get Stat-O-Seals as it is, are they available from an aviation source in Viton?

Its easy to say replace with Viton, but I believe there are many special items that it’s just not possible.

[Marc_B]

https://www.beechtalk.com/forums/viewtopic.php?f=7&t=234904&start=150

Several responses from Mr. Braly recently on BT and several comments pertinent to Mooneys.

[A64Pilot]

I think in truth that in a year or so we will know if in fact there is nothing to see here, or it may go the way the Mobil-1 oil did.

But we just won’t know until then at earliest. It could be fine or not.

[Marc_B]

I just hate the lawyer speak of no "change" needed if you follow "best practices."  Shouldn't the company that performed testing over 14 years with a new product on the market be the best and ideal one to tell owners what the best practice is with their fuel??

I can't tell if Mr. Braly really thinks that all of the issues shown recently are fabrication and untrue, or if he just feels that Mooneys leak, that's what they all do, so nothing to see here. 

I started to cut and paste his responses but wasn't sure if 1) this was ok with both MS and BT, and 2) I wasn't sure what to link.  (and a distant 3, his responses kinda didn't sit well with me to be perfectly honest.)

Agree, @A64Pilot may be nothing to see here; as we get closer to deadlines we'll likely see more activity as well as more field reports.  Peace out...fingers crossed for a brave new world in 2025!

[Justin Schmidt]

On 12/28/2024 at 2:24 PM, ragedracer1977 said:

My confidence level decreases with every non-answer Braly gives.

Did he run over your dog or something 

[ragedracer1977]

23 minutes ago, Justin Schmidt said:

Did he run over your dog or something 

Not yet. At the moment he’s just asking me to risk my life and the life of others on “because I said so” and I kinda think that’s worse

[Justin Schmidt]

4 minutes ago, ragedracer1977 said:

Not yet. At the moment he’s just asking me to risk my life and the life of others on “because I said so” and I kinda think that’s worse

Well, HE isn't asking or forcing you to do anything. He offers a product through STC and you ARE free to use or not.

All this conjecture, innuendo, fear mongering gets everyone nowhere and damn near libel. As an engineer jumping to conclusions, biases, not following proper engineering processes, not following hard data and numbers in a controlled manner is a fast way to end a career.

If those with issues work directly with GAMI and/or an independent materials engineer to figure out exact cause and not go off on a half cocked toddler tantrum thing could resolve more smoothly.

I doubt George has falsified data, lied or other wise tricked people, I'm sure he likes his freedom.

Remember, in engineering or science the mere presence of an issue does not point to a cause. Free to your own opinion, not your own facts

 

 

[MikeOH]

10 minutes ago, Justin Schmidt said:

Well, HE isn't asking or forcing you to do anything. He offers a product through STC and you ARE free to use or not.

Not at this moment.  But, here in Kalifornia (coming soon to the rest of country) the plan is to soon BAN 100LL.  At that point, yes, we will be FORCED to buy G100UL if no other unleaded fuel is available to compete.  If banning of 100LL wasn't an issue I wouldn't even participate in this debate.  Buy, don't buy, we should be free to choose.

[ragedracer1977]

On 12/28/2024 at 4:44 PM, George Braly said:

 

The following are hard facts:

 Are they? Since many are not facts- I’d like references for the rest- comments in bold italic underline are mine.

For the last forty-four years - - various OEMs have been recommending the replacement of nitrile / buna N  fuel system components with "modern"  fluorosilicone type O-rings, gaskets, seals and other fuel wetted components in our aircraft. 
 

which OEMs and how do we find out which seals etc to replace and a cross reference?

There is a 1980 (yes,  44 years ago)  Allied Signal / Bendix service document that states exactly that.   It is not a mere coincidence that was happening in 1980.  The "timing" of that Bendix service document is consistent with the advent / roll-out of 100LL (which first began about 10 years earlier).  As mentioned elsewhere, that fuel often (nearly always) contained significant levels of toluene.   A whole new small maintenance business was created to reseal Mooney fuel tanks (example:  Weep No More, in Minn.) 

This is misleading.  Weep No more was founded in 2010.  Paul (with Bruce Jaeger) didn’t start working on fuel tanks until the early 2000’s.  So, 100LL took something like 20 years to damage sealant? Or was it 40 year old sealant failing? My Mooney - a 1963 model - was resealed by Paul in 2016.  36 years after the roll out of 100LL and 53 years after it rolled off the factory floor.  

A C-421 owner on BT reported that when he recently ordered new seals and O-rings from Textron, they were Viton and fluorosilicone - -  not nitrile.   

that’s not exactly what he said. He said replacements were listed on textron as such, but not on RAMs site.  This was only for some of the seals ($5000 USD was his estimate for parts for just seals and orings on the fuel strainers) he still needed to research all hoses and other related parts.

 

When GAMI was first drafting the ICAs to go with the G100UL Avgas STC,  the Wichita Certification engineers forwarded that draft (as they are supposed to do) to the FAA  "AEG" group (now AED) for review.  The AEG group is a subdivision of Flight Standards that is responsible for maintenance instructions.  The AEG group actually asked GAMI to make the language in the ICAs related to the replacement of older style O-rings, hoses, and gaskets, "more explicit"  or "stronger" , as the AEG group had been trying to get the industry and the mechanics to stop using nitrile type O-rings and seals as replacements - - for decades.  
 Why didn’t you?? I have to admit, I find it suspect that they (AEG) want everyone to willy nilly replace every seal etc in contravention to parts and maintenance manuals. We (owners and mechanics) can’t just decide to use a different material because we like it better.

I will try to provide data to support the answers. 

Please do!

George

 

 

 

 

[Justin Schmidt]

10 minutes ago, MikeOH said:

Not at this moment.  But, here in Kalifornia (coming soon to the rest of country) the plan is to soon BAN 100LL.  At that point, yes, we will be FORCED to buy G100UL if no other unleaded fuel is available to compete.  If banning of 100LL wasn't an issue I wouldn't even participate in this debate.  Buy, don't buy, we should be free to choose.

All do respect, that isn't GAMI. That is your insane mentally deranged politicians, which also exist elsewhere and federally. That is the importance of organizing and being involved in politics as well as supporting AOPA and EAA, that of which they didn't exist, neither would GA.

Also, the lead issue has been massively slow walked for decades, and now rooster came home to roost 

[ragedracer1977]

28 minutes ago, Justin Schmidt said:

Well, HE isn't asking or forcing you to do anything. He offers a product through STC and you ARE free to use or not.

 

Yeah, sorry. I disagree.  He is actively working and supporting the move to ban 100LL in California to force his product (the only currently available)  as the single source for avfuel.

 

 If he wasn’t actively pushing for that, I’d feel differently.

[Justin Schmidt]

Just now, ragedracer1977 said:

Yeah, sorry. I disagree.  He is actively working and supporting the move to ban 100LL in California to force his product (the only currently available)  as the single source for avfuel.

 

 If he wasn’t actively pushing for that, I’d feel differently.

Can you point me to something from him regarding that?

[Marc_B]

@Justin Schmidt

https://www.congress.gov/117/meeting/house/115056/witnesses/HHRG-117-GO28-Wstate-BralyG-20220728.pdf

https://www.avweb.com/aviation-news/environmental-group-says-california-fbos-will-be-able-to-continue-selling-100ll/

Edit: It's a business move and not unexpected.  We're moving towards an unleaded future and GAMI is helping to make that happen sooner than the PAFI/EAGLE Program.  So of course they are proponents of ending lead...but that's just smart business for GAMI.

[MikeOH]

6 minutes ago, Justin Schmidt said:

All do respect, that isn't GAMI. That is your insane mentally deranged politicians, which also exist elsewhere and federally. That is the importance of organizing and being involved in politics as well as supporting AOPA and EAA, that of which they didn't exist, neither would GA.

Also, the lead issue has been massively slow walked for decades, and now rooster came home to roost 

I never claimed, or blamed, GAMI/George for the politics. But, as you point out, it's the Feds as well as Kalifornia...so, the mandates will come EVERYWHERE.

Frankly, I don't believe the threat from airborne lead is significant...see my previous post sharing southern California AQMD airborne lead testing around a GA airport and the resultant very LOW lead levels, comparable to those in the rest of the Los Angeles basin.  Point being, they can continue to 'slow roll' this indefinitely as far as I'm concerned.

[Schllc]

5 minutes ago, MikeOH said:

Frankly, I don't believe the threat from airborne lead is significant...see my previous post sharing southern California AQMD airborne lead testing around a GA airport and the resultant very LOW lead levels, comparable to those in the rest of the Los Angeles basin.  Point being, they can continue to 'slow roll' this indefinitely as far as I'm concerned.

^^^^^^^^^This!!!^^^^^^^^^
 

If you pee into the ocean, you have technically raised sea levels. 

[Justin Schmidt]

2 minutes ago, MikeOH said:

I never claimed, or blamed, GAMI/George for the politics. But, as you point out, it's the Feds as well as Kalifornia...so, the mandates will come EVERYWHERE.

Frankly, I don't believe the threat from airborne lead is significant...see my previous post sharing southern California AQMD airborne lead testing around a GA airport and the resultant very LOW lead levels, comparable to those in the rest of the Los Angeles basin.  Point being, they can continue to 'slow roll' this indefinitely as far as I'm concerned.

I agree that airborne lead from GA is massively overblown. From some very biased questionable "studies". We went from lead in everything, not being able to go 10 minutes with contacting it, which did cause sever problems to very few places that use it today. I get more contact with lead from an hr at the range then I will ever in aviation. 

The politics remain that faa, other feds, airlines, people in general do not want GA to exist and it is an attack path, and it's here. Shits at the door , now what do we do .

[Marc_B]

@Justin Schmidt The basic chess in California:

The four major distributors of aviation fuel in California are Avfuel, World Fuel, TITAN, and EPIC.

GAMI is working with Vitol to mix ~1 million gallons of G100UL.

California's use of 100LL annually is ____ gallons per year (edit: I'm not sure...see post below)

Previous Consent Judgement from 2014 with 26 FBOs (9 of which are now out of business or sold) originally was based on not having proper signage that 100LL could cause cancer in the state of California.  Before final judgment, they added language about moving to unleaded fuel when it was "commercially available" but didn't completely spell out what that meant. 

Commercially Available definition being pushed is that an unleaded fuel "is commercially available" when an FBO can call Distributor (Vitol) and order Unleaded AvGas (G100UL) and have it delivered.  I believe this will go in front of the court early this coming year.  If the court finds in favor of CEH, then 100LL would be banned from distributors at risk of fines spelled out in the decree.

https://www.avweb.com/aviation-news/g100ul-court-action/

[ragedracer1977]

I think 100LL is more like 20,000,000+ gallons a year in California, FYI.

[Marc_B]

58 minutes ago, ragedracer1977 said:

I think 100LL is more like 20,000,000+ gallons a year in California, FYI.

Not sure where I got previous number...what I just found on EIA (aligned with @ragedracer1977)...

[MikeOH]

Which is pretty close to 20,000,000