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

[T. Peterson]

12 hours ago, Andy95W said:

Sorry to disagree, but I would say this is exactly in keeping with the spirit of the STC purely by definition.

The Type Certificate for your airplane specifies the fuel to be used.  For your 231, the TC requires either 100LL (blue) or 100/130 (green) fuel.  To legally use something different, you have to deviate from your Type Certificate- by utilizing a Supplemental Type Certificate.

Good afternoon Andy and Happy New Year!

First Mr. Braly responded to a post of mine and now you! I certainly have wandered into a branch of intellectual prowess which far exceeds my own! Therefore believe me when I say I proceed with the utmost humility and respect for all those who have expressed disagreement with my point of view.

In a normal context, Andy, I would say that your rebuttal is iron clad, and I would have no argument. However as we say in theological circles, “Context is King”, and I think context is critical to this discussion. I believe the intent of an STC is to provide a safe method to modify an airplane for some user desired objective. The key is “user desired”. The user wants his airplane to use a more powerful engine, use cheaper fuel, use a better wastegate and etc. Because it’s an airplane with huge safety ramifications Bubba and Otis can’t just go hang a Corvette engine on the front and say let’s see how this works! There is careful engineering and extensive testing which is presented to the FAA and if they deem it sound an STC is granted to that developer. But the bottom line is it is driven by demand. The developer anticipates a demand and provides the product for a fee. It’s a win win for everybody. The STC holder makes a profit and I get the coveted GAMI injectors, Merlyn wastegate, authorization to use Mogas or a Rocket engine etc.

Now if a modification needs to be made due to a safety concern, the FAA doesn’t issue an STC, they issue an Airworthiness Directive. That’s a horse of a different color. It is also where I think the FAA has stepped into the quagmire.

In their hurry to accommodate political pressure they issued a blanket approval for a particular fuel for which there is virtually no demand! But neither is there justification to issue an AD against 100LL. They don’t need an AD against it, if the government just removes it. What is effectively being done is to masquerade an AD as an STC! 

Furthermore, since the FAA are the rule-makers, can the argument not be made that if they issue a blanket approval then that automatically would adjust the Type Certificate to also include G100UL? It seems as if the FAA wants to eat their cake and have it too.

It also seems to me that if I am wrong about all this and the STC is justified due to the language of the Type Certificate, then no fuel can ever be justified without an STC and any language referencing “drop-in-fuel” is simply disingenuous.

[George Braly]

18 minutes ago, Shiroyuki said:

I sincerly apreciate your reply.

I used to be a firm supporter of G100UL and really hoped it is a direct drop in replacement. However these issue that emerged in the past weeks, and your deflective answer doesn't inspire any confidence for me as an owner. 

When we ask if your fuel will damage our paint, you keep saying under normal circustances it won't. But we want to know what about specific circumstances that happens on our plane?

To be honest, at this point I will stick with 100LL until G100UL is more widely used, when it is proven by other user.

 

I think it is rather inappropriate to state that I give "deflective" answers to your questions.   What I have provided is hard data.  Exposure data with controls.   

There is simply not enough information about the circumstances in California with the Mooney for us to be able to do any more than speculate.  

We are continuing to investigate the matter.   That does require some time.   If I recall, one of the U-Tube reports "dropped" one day before Christmas.   This is New Year's Day. 

What I do find somewhat frustrating is that, when GAMI does provide relevant aircraft paint exposure data - - with experimental controls - -  that data is dismissed  by several of the participants here, as not being sufficient to further the discussion. 

Regardless, as stated above,  we will, with all deliberate speed, continue to investigate the matter. 

 

[gabez]

@George Braly I posted the sealant used to reseal my aux. I can also email it to you, the work was done 9/22 no leaks until I have started using G100. 

Putting all the good faith aside which we all appreciate, I think the requirement of cleaning up a spill as soon as possible is quite unreasonable. While refueling, while sumping the drain valve, while just having a mechanic work on your plane, or fuel tanks leaks that happen all the time. Fuel will leak and we won't always be there to clean it up. Drain valve will leak, after sumping, there is always drops of fuel coming out. 

My plane doesn't have a great paint job and I am lucky enough that i decided not to repaint it last year. The bottom of my copilot wing is ruined beyond touch up paint. I honestly don't think I will repaint the plane unless I am going to forever use 100LL. I cannot foresee investing 15-20K in a paint job and then having to lose sleep at night because of G100. I am also going to have to explain this entire thread(s) to who ever is going to buy my plane when I sell it and I am going to have to take a hit on the sale price. 

Honestly, KWVI and Gami should have done a better job when promoting the fuel. What we are seeing here (including the green encore) is orthogonal from what it was disclosed. We were also encouraged  to purchase G100. I am attaching the statement in the email. Note: "no different than 100LL".

As you stated yourself there are 2 STC, one of the engine and one for the airframe. G100 is different than 100UL when it comes to the airframe. They do not operate the same

Gabe

Edited January 2 by gabez

[Z W]

A reminder in this day and age - 

You can't trust every picture and video you see on the internet.

[tony]

21 hours ago, George Braly said:

 

I think it is rather inappropriate to state that I give "deflective" answers to your questions.   What I have provided is hard data.  Exposure data with controls.   

There is simply not enough information about the circumstances in California with the Mooney for us to be able to do any more than speculate.  

We are continuing to investigate the matter.   That does require some time.   If I recall, one of the U-Tube reports "dropped" one day before Christmas.   This is New Year's Day. 

What I do find somewhat frustrating is that, when GAMI does provide relevant aircraft paint exposure data - - with experimental controls - -  that data is dismissed  by several of the participants here, as not being sufficient to further the discussion. 

Regardless, as stated above,  we will, with all deliberate speed, continue to investigate the matter. 

 

George, I know this is not exactly a friendly environment for you, and I'm not a proponent of how we got here, but I do appreciate you logging in.  It would be easier to just turn off the computer.  

[redbaron1982]

I think it would be wise for GAMI to remove this from their website:

It is clear at this point that G100UL is not transparent to the engine, aircraft, and pilot. Hard data is pointing out that:

• Paint staining has been reported by many, in none of the cases buffing or polishing was able to remove the stains.
• Paint damage (as in paint peeling off) has been reported.
• Fuel tank seal damage has been reported.
• Some o-ring materials swell significantly more than with 100LL. If that generates any issue, it is still not clear.

I'm not saying that G100UL is good or bad. I'm saying that it should be clearly stated in which aspects it is different than 100LL and in which scenarios (certain o-ring materials, wet wing aircraft with old sealants, paint that is not in mint condition, etc) there is an elevated risk of having issues during the transition.

[gabez]

5 minutes ago, redbaron1982 said:

I think it would be wise for GAMI to remove this from their website:

It is clear at this point that G100UL is not transparent to the engine, aircraft, and pilot. Hard data is pointing out that:

• Paint staining has been reported by many, in none of the cases buffing or polishing was able to remove the stains.
• Paint damage (as in paint peeling off) has been reported.
• Fuel tank seal damage has been reported.
• Some o-ring materials swell significantly more than with 100LL. If that generates any issue, it is still not clear.

I'm not saying that G100UL is good or bad. I'm saying that it should be clearly stated in which aspects it is different than 100LL and in which scenarios (certain o-ring materials, wet wing aircraft with old sealants, paint that is not in mint condition, etc) there is an elevated risk of having issues during the transition.

I think if they remove it, it can be pursued as admission of guilt, so believe it or not, it's better to leave it there and see how this plays out 

[EricJ]

21 hours ago, George Braly said:

I think it is rather inappropriate to state that I give "deflective" answers to your questions.   What I have provided is hard data.  Exposure data with controls.   

FWIW, you don't get to determine whether you come across as deflective or not to somebody.  If they think you're being deflective, then it's 100% appropriate for them to say so.   FWIW, I also think you're often very deflective.

21 hours ago, George Braly said:

What I do find somewhat frustrating is that, when GAMI does provide relevant aircraft paint exposure data - - with experimental controls - -  that data is dismissed  by several of the participants here, as not being sufficient to further the discussion. 

Your data will always be under suspicion due to the obvious conflict of interest.   There have now been multiple aircraft of different makes showing photographic evidence of significant paint damage, i.e., bubbling and peeling, after use of G100UL, and those are just the ones have been shown or linked on this site.   I'm sure that's not a comprehensive inventory of the entire field.   The YT vid by mluvara did a good job of reproducing the conditions suspected to create the damage and 100% of the different articles tested in G100UL failed.   So when you produce a single test with a single type of test item that doesn't appear to reproduce the same field conditions, then, yes, there's going to be some pushback, notwithstanding the conflict of interest.   A cynic might say the test was designed specifically to not show the issue.

 

21 hours ago, George Braly said:

Regardless, as stated above,  we will, with all deliberate speed, continue to investigate the matter. 

What it needs is more independent third party testing to remove the conflict of interest.

[Paul Thomas]

12 minutes ago, EricJ said:

What it needs is more independent third party testing to remove the conflict of interest.

I feel a bit like a fraud, because I wouldn't put G100UL in my airplane at this point but let me make a counter argument.

I understand where you are coming from and the youTube video is bothersome. However, if I had a product that I believed in, why should I pay for every test demand by people who appear to have no interest in being my customer? If you start to pay for tests, at what point do you stop? Whenever you do, it will likely appear that an issue has been found.

I can see how third party testing would be advantageous from a marketing perspective -- and I'm starting to think marketing is the biggest issues with G100UL -- but otherwise people are free to use or not use the product. There are clearly two very loud bases here but much fewer users.

I believe that the biggest advantage that G100UL will have is time and being the first mover. Whatever are created by G100UL, they will be shown in the field. Most of them will show up quickly, some will likely take some time. Absent immediate failure, as more time passes, more and more customers that are willing to take that chance on the fuel and demand will grow.  When other fuels are introduced, I have a feeling they'll have a lot of pushback as well.

[EricJ]

35 minutes ago, Paul Thomas said:

When other fuels are introduced, I have a feeling they'll have a lot of pushback as well.

If on introduction to the general market they cause damage and create safety concerns, there ought to be pushback!

Scott Manley (YT guy) did an interesting analysis of the chemical history of aviation fuels and a short assessment of where we are now.   He made an interesting point at the end, that Swift has indicated that 100R is miscible with 100LL but not G100UL.  The VP fuel appears, from what I can gather and what he said, is taking a similar formulation path, so the potential situation may be that 100R and VPs fuels are miscible with each other and 100LL, but not G100UL.   If Swift and VP both attain ASTM standards, they will have more industrial support than G100UL.    This may create a situation where people have to closely monitor whether there is any G100UL in their tank so as to be careful to not mix it with the other unleaded fuels.   This could create a contracting market for G100UL, assuming it gets traction given the current environment.

So I understand why GAMI is pushing hard to get first mover advantage and gain whatever market share that they can, but it looks to me like the cards are not in their favor given the miscibility issues with the others and the greater support for the others given ASTM status.   The ASTM process assures the "coalition approach" features and broader support as mentioned in the Textron letters.

Scott Manley's recent vid:

https://www.youtube.com/watch?v=8zfIy17q9sE

 

[A64Pilot]

7 hours ago, EricJ said:

What it needs is more independent third party testing to remove the conflict of interest.

I have no idea how widespread this fuel is or how many aircraft use it, but I’d suspect that before long in California it will become very widespread as other Jurisdictions jump onto the ban lead bandwagon, but never having lived there that’s just my guess.

What I’m getting at is that there are several independent third party testers, the users of the fuel, if in fact the fuel is causing issues this early after it’s adoption, then the number of aircraft that are having problems will increase with the number of users.

Plus and this is just from my own experience with chemicals reacting with fuel tank sealant and paint, the longer the paint and sealant is exposed if there is a problem, it will get worse.

I’m thinking that if in fact there is a problem, it will become pretty apparent with the passage of time and increase in users. Mooney’s aren’t the only aircraft with wet wings.

In truth I think the only real test, or arguably the true acid test is to put it out there and see what happens, hopefully nothing.

By the way, what’s this selling for per gl?

 

[Brian2034]

I questioned the wisdom of an alternative fuel on other threads and its timeline.

I’ve been involved in aviation for 30 years and watched the alternative fuel issues and updates for almost the same amount of time. 
My question is, why are we trying to reinvent the wheel!
Would it not be easier to figure out how to use auto gas in all aircraft engines and airframes?

Autogas would be globally the most abundant and economical product available.

For example a Piper Cherokee 140 requires nothing but a STC sticker to run autogas.

 A Piper warrior requires a duel fuel pump upgrade ($5000) but with the upgrade and now being able to run auto gas, depending on fuel prices and hours flown the upgrade will pay for itself in a very short time.

Let’s face reality, the demand for 100ll or an alternative fuel is low compared to autogas.

 

 

 

[IvanP]

7 hours ago, Paul Thomas said:

I feel a bit like a fraud, because I wouldn't put G100UL in my airplane at this point but let me make a counter argument.

I can see how third party testing would be advantageous from a marketing perspective -- and I'm starting to think marketing is the biggest issues with G100UL -- but otherwise people are free to use or not use the product.

Whille wee may be free to not use G100LL for now, that "freedom" will be short lived and, unless there will be another alternative on the market soon, this fuel may be the only fuel available. Absent some seismic shift in the political landscape, 100LL will be banned sooner than later. My home state of CA probably being the frontrunner, as with many other misguided and wasteful mandates. 

[Pinecone]

12 hours ago, Brian2034 said:

Autogas would be globally the most abundant and economical product available.

Except that MOGAS is highly variable.  Especially when you get outside the US.

In the old days, you could blow up your car running Mexican auto fuel.

[A64Pilot]

14 hours ago, Brian2034 said:

I questioned the wisdom of an alternative fuel on other threads and its timeline.

I’ve been involved in aviation for 30 years and watched the alternative fuel issues and updates for almost the same amount of time. 
My question is, why are we trying to reinvent the wheel!
Would it not be easier to figure out how to use auto gas in all aircraft engines and airframes?

Autogas would be globally the most abundant and economical product available.

For example a Piper Cherokee 140 requires nothing but a STC sticker to run autogas.

 A Piper warrior requires a duel fuel pump upgrade ($5000) but with the upgrade and now being able to run auto gas, depending on fuel prices and hours flown the upgrade will pay for itself in a very short time.

Let’s face reality, the demand for 100ll or an alternative fuel is low compared to autogas.

 

 

 

The low compression Mooney’s should do fine on 87 Octane car gas, but none of the high compression fuel injected or I’m sure Turbo ones could. They would need ADI.

I bet as we are all low wing that it’s likely that airframe modifications would likely have to be made, but even some high wing aircraft need them too, Maule does. It’s because car gas is much more likely to vapor lock.

I’m sure our fuel injected but not turbo would burn car gas just fine with ADI, the turbo ones are said to be able to, but I’m guessing that if you don’t want the ADI on all of the time it might mean reduced boost in cruise.

Current use of ADI is if cyl head temp is above 400F OR MP at or above 25 MP, below both of those and ADI is off, from what I read those are very conservative settings very much on the safe side, but as the fluid is cheap why not be extra safe?

[T. Peterson]

16 hours ago, IvanP said:

Whille wee may be free to not use G100LL for now, that "freedom" will be short lived and, unless there will be another alternative on the market soon, this fuel may be the only fuel available. Absent some seismic shift in the political landscape, 100LL will be banned sooner than later. My home state of CA probably being the frontrunner, as with many other misguided and wasteful mandates. 

I am hoping that with the seeming cultural shift as evidenced in the recent election, there will be a pushback from at least most of the flyover states. I am not asking that 100LL be anointed, only that any potential alternative be subject to free market forces. The ultimate 3rd party testing will be by customers. 

[Brian2034]

7 hours ago, A64Pilot said:

The low compression Mooney’s should do fine on 87 Octane car gas, but none of the high compression fuel injected or I’m sure Turbo ones could. They would need ADI.

I bet as we are all low wing that it’s likely that airframe modifications would likely have to be made, but even some high wing aircraft need them too, Maule does. It’s because car gas is much more likely to vapor lock.

I’m sure our fuel injected but not turbo would burn car gas just fine with ADI, the turbo ones are said to be able to, but I’m guessing that if you don’t want the ADI on all of the time it might mean reduced boost in cruise.

Current use of ADI is if cyl head temp is above 400F OR MP at or above 25 MP, below both of those and ADI is off, from what I read those are very conservative settings very much on the safe side, but as the fluid is cheap why not be extra safe?

Yes, I believe all lower compression aircraft can run mogas including the Mooneys. We have a hangar full of aircraft and 90 percent run mogas, we also had a homebuilt aircraft with an AeroSport Power IO-375 running exclusively auto gas for hundreds of hour with no issues.

Problem I have is the extremely high cost of 100ll in our area and the lack of a mogas STC for the Mooney. (even the lower compression Mooneys). If and when an alternative fuel becomes reality, im sure it will be even more costly than 100ll. As I mentioned in an earlier post the Peterson STC for a Piper Warrior requires a fuel pump upgrade. Did Peterson go through the same regimen with the Mooneys as they did with Piper?

 

[Brian2034]

9 hours ago, Pinecone said:

Except that MOGAS is highly variable.  Especially when you get outside the US.

In the old days, you could blow up your car running Mexican auto fuel.

Obviously, there is a minimum standard that would have to be adhered to and also it would have to be ethanol free mogas .  Wouldn’t it be easier for the major fuel manufacturers to provide non ethanol unleaded fuel (mogas) for the aircraft industry?

 

[A64Pilot]

I don’t know, but I think either a Mooney was too hard to get to run on Mogas, or more likely in my opinion the interest for people who wanted to run car gas in their Mooney’s just wasn’t there. I don’t see why a Mooney would be harder than a Piper? Carbureted low compression 180 HP Mooney’s that is.

Interest in auto fuel STC’s and ADI just went away, largely I think because Mogas is rare at airports and who wants to schlep gas in 5 gl cans. I had a 100 gl tank in my truck that I used for my boat and C-140, but most don’t and I think some airports won’t let you self fuel. Where I kept mine was a little town and they didn’t care.

A LOT of interest in car gas is from people who live in places like Alaska say where Avgas is tough to get, but car gas is easier to get and if you have to have your Avgas flown in a Beaver it’s way cheaper too.

I don’t know of any maintenance requirement of ADI except replace that cheap auto electric fuel pump if or when it fails.

Looked like a facet pump to me on the video.

[A64Pilot]

2 minutes ago, Brian2034 said:

Obviously, there is a minimum standard that would have to be adhered to and also it would have to be ethanol free mogas .  Wouldn’t it be easier for the major fuel manufacturers to provide non ethanol unleaded fuel (mogas) for the aircraft industry?

 

One way I see it could happen is we get 94UL, that I know could go into widespread distribution almost overnight, you just keep making the same Avgas you have for decades, just don’t put lead in it, shipping, distribution etc all remain the same. Those that don’t have high compression engines just burn it, those with high compression / turbo’s run ADI. That way you get honest Avgas that meets specs, the aircraft should require no mods  to prevent vapor lock, it has the same storage life of 100LL, shouldn’t be any more expensive than 100LL, plus it will go into the same trucks and tanks etc that 100LL did as it’s just 100LL, without the lead I think? And we know it won’t cause any issues, except maybe valve recession, but I think any unleaded fuel may cause that, unless we leave a little lead in or add an additive, they exist.

An issue with car gas as I see it is getting it, it’s one thing to be able to burn it and another to get it. 

[George Braly]

On 1/2/2025 at 12:02 PM, EricJ said:

FWIW, you don't get to determine whether you come across as deflective or not to somebody.  If they think you're being deflective, then it's 100% appropriate for them to say so.   FWIW, I also think you're often very deflective.

Your data will always be under suspicion due to the obvious conflict of interest.   There have now been multiple aircraft of different makes showing photographic evidence of significant paint damage, i.e., bubbling and peeling, after use of G100UL, and those are just the ones have been shown or linked on this site.   I'm sure that's not a comprehensive inventory of the entire field.   The YT vid by mluvara did a good job of reproducing the conditions suspected to create the damage and 100% of the different articles tested in G100UL failed.   So when you produce a single test with a single type of test item that doesn't appear to reproduce the same field conditions, then, yes, there's going to be some pushback, notwithstanding the conflict of interest.   A cynic might say the test was designed specifically to not show the issue.

 

What it needs is more independent third party testing to remove the conflict of interest.

1) Your response details a number of the reasons I made the offer to host a delegation of Mooney folks to visit GAMI and go through all of the testing.  You are, apparently, unaware of the significant level of third party independent testing that has been done - - without involvement by GAMI.  All of that is part of the certification file.  Your criticism of the testing GAMI did under the direct (in person) oversight of the FAA is noted.   And has been noted by some folks in the FAA and received by them as a direct challenge to their integrity and competency. 

2) I am not sure how I could have designed that U-tube  test to more clearly show any differences that might occur in the paint integrity than what is seen in the video.  But I am open to suggestions as to how to improve upon that test.  

3) As to the small number of planes with paint issues - -  I am specifically aware of two.  The Mooney and a Twin Cessna.  There may be more.   However, we have fueled up well over 30 different aircraft with G100UL on our ramp.  In addition there were about 50 that fueled up at KRHV when we did the STC day there.   Several of those were Mooneys who had no subsequent issues.   Given the Watsonville set of aircraft then there are probably about 100 different aircraft that have used G100UL avgas.  

Given that one of those aircraft has been using G100UL avgas for 14 years - - with no paint damage and no leakage - -  then collectively that represents a fairly robust demonstration.    

If one does a technically informed deep dive into the sealant / fuel compatibility world, then one can begin to articulate some reasons for the fuel leaks on those two aircraft reported in this forum.

Reality:  Mooney aircraft have been having fuel tank leaks and paint damage for more than 40 years - - going back to the 1980 time frame.  That is most likely due to the novel method of wet-wing fuel tank construction adopted by Mooney on the production line in Kerrville, which I visited several times in the late 1960s. 

Regards,  

George

 

  

 

[Brian2034]

26 minutes ago, A64Pilot said:

I don’t know, but I think either a Mooney was too hard to get to run on Mogas, or more likely in my opinion the interest for people who wanted to run car gas in their Mooney’s just wasn’t there. I don’t see why a Mooney would be harder than a Piper? Carbureted low compression 180 HP Mooney’s that is.

Interest in auto fuel STC’s and ADI just went away, largely I think because Mogas is rare at airports and who wants to schlep gas in 5 gl cans. I had a 100 gl tank in my truck that I used for my boat and C-140, but most don’t and I think some airports won’t let you self fuel. Where I kept mine was a little town and they didn’t care.

A LOT of interest in car gas is from people who live in places like Alaska say where Avgas is tough to get, but car gas is easier to get and if you have to have your Avgas flown in a Beaver it’s way cheaper too.

I don’t know of any maintenance requirement of ADI except replace that cheap auto electric fuel pump if or when it fails.

Looked like a facet pump to me on the video.

 

29 minutes ago, A64Pilot said:

I don’t know, but I think either a Mooney was too hard to get to run on Mogas, or more likely in my opinion the interest for people who wanted to run car gas in their Mooney’s just wasn’t there. I don’t see why a Mooney would be harder than a Piper? Carbureted low compression 180 HP Mooney’s that is.

Interest in auto fuel STC’s and ADI just went away, largely I think because Mogas is rare at airports and who wants to schlep gas in 5 gl cans. I had a 100 gl tank in my truck that I used for my boat and C-140, but most don’t and I think some airports won’t let you self fuel. Where I kept mine was a little town and they didn’t care.

A LOT of interest in car gas is from people who live in places like Alaska say where Avgas is tough to get, but car gas is easier to get and if you have to have your Avgas flown in a Beaver it’s way cheaper too.

I don’t know of any maintenance requirement of ADI except replace that cheap auto electric fuel pump if or when it fails.

Looked like a facet pump to me on the video.

Exactly, my thinking also, there wasn’t enough of a Mooney demand for a mogas STC !

I guess I’m lucky and unlucky, I live in an area where there is limited access to 100ll and it’s costly!
Also they say ethanol will not be added to mogas in our area as of yet because of the low consumption and limited shelf life of the fuel when added.

Aviation is expensive but with 100ll in our area selling for $18.00 cad. for a Us. Gallon it definitely cuts into the flying budget.

For example flying our Piper Warrior on mogas instead of 100ll for 100 hours at a consumption of 8 us gallons per hour would cost $6500 as compared to $14000 for 100ll. 
 

[Brian2034]

I’m guessing at least half the aircraft fleet in the world are capable of running on mogas, wouldn’t it be easier for the powers that be to revisit the STC process for all aircraft and make whatever modifications are required for the use of mogas.

Then with the increased demand for non- ethanol mogas and its required use in general aviation ???

In our area we have thousands of hours on aircraft using mogas with no issues.  Clean running, no valve issues, 50 hour oil changes look like new oil, in some cases better performing engines, spark plugs come out perfect, much cleaner bellies on aircraft.

[EricJ]

2 hours ago, George Braly said:

1) Your response details a number of the reasons I made the offer to host a delegation of Mooney folks to visit GAMI and go through all of the testing.  You are, apparently, unaware of the significant level of third party independent testing that has been done - - without involvement by GAMI.  All of that is part of the certification file.  Your criticism of the testing GAMI did under the direct (in person) oversight of the FAA is noted.   And has been noted by some folks in the FAA and received by them as a direct challenge to their integrity and competency. 

I'm well aware, but you missed the point that your demonstration with the cowl flaps is not free of conflict of interest and was not independent.  This is an example of why some people find you deflective. 

2 hours ago, George Braly said:

2) I am not sure how I could have designed that U-tube  test to more clearly show any differences that might occur in the paint integrity than what is seen in the video.  But I am open to suggestions as to how to improve upon that test.  

3) As to the small number of planes with paint issues - -  I am specifically aware of two.  The Mooney and a Twin Cessna.  There may be more. 

This is discouraging, as there are two Mooneys and a third aircraft that have been reported here.   If there is also a twin Cessna then that's four.   If you're not aware of the scope of the problem, that is a concern in itself, as I suspect that's not a even a comprehensive list.

2 hours ago, George Braly said:

However, we have fueled up well over 30 different aircraft with G100UL on our ramp.  In addition there were about 50 that fueled up at KRHV when we did the STC day there.   Several of those were Mooneys who had no subsequent issues.   Given the Watsonville set of aircraft then there are probably about 100 different aircraft that have used G100UL avgas.  

Given that one of those aircraft has been using G100UL avgas for 14 years - - with no paint damage and no leakage - -  then collectively that represents a fairly robust demonstration.    

If one does a technically informed deep dive into the sealant / fuel compatibility world, then one can begin to articulate some reasons for the fuel leaks on those two aircraft reported in this forum.

Reality:  Mooney aircraft have been having fuel tank leaks and paint damage for more than 40 years - - going back to the 1980 time frame.  That is most likely due to the novel method of wet-wing fuel tank construction adopted by Mooney on the production line in Kerrville, which I visited several times in the late 1960s. 

Regards,  

George

I'm not trying to be negative, but again this seems like deflection.  If a food additive is killing a very small percentage of the consumers, moving focus to the vast number of survivors is not helpful.   Blaming the victims for 'you already had leaky tanks', is also not particularly helpful, especially when the fuel has been advertised "that operates no differently than the 100LL that you are accustomed to".   There are significant concerns that go to the safety of operation of aircraft using G100UL, especially in the long term in the context of latent failures and increased maintenance.   Continuing to deflect the concerns as "inappropriate" or otherwise not significant is concerning in itself and is further eroding confidence for some of us.

[redbaron1982]

42 minutes ago, EricJ said:

I'm well aware, but you missed the point that your demonstration with the cowl flaps is not free of conflict of interest and was not independent.  This is an example of why some people find you deflective. 

This is discouraging, as there are two Mooneys and a third aircraft that have been reported here.   If there is also a twin Cessna then that's four.   If you're not aware of the scope of the problem, that is a concern in itself, as I suspect that's not a even a comprehensive list.

I'm not trying to be negative, but again this seems like deflection.  If a food additive is killing a very small percentage of the consumers, moving focus to the vast number of survivors is not helpful.   Blaming the victims for 'you already had leaky tanks', is also not particularly helpful, especially when the fuel has been advertised "that operates no differently than the 100LL that you are accustomed to".   There are significant concerns that go to the safety of operation of aircraft using G100UL, especially in the long term in the context of latent failures and increased maintenance.   Continuing to deflect the concerns as "inappropriate" or otherwise not significant is concerning in itself and is further eroding confidence for some of us.

4 out of 100, that's not small... It means that G100UL is not a drop in replacement for at least 4% of the fleet. I wonder what's is the threshold required to consider that there is an alternative to 100LL. Is it 80% of the fleet? 90%? 95%?