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

[gabez]

if you watch this video, around minute 19:00 you will see someone spraying the wing of the plane with a substance and wiping it (bottom right), this video is 9 months old, GAMI knew the fuel would stain the paint independently of the vintage. they just tone it down to "creates the potential for staining" as supposed to "will stain"
 

 

[A64Pilot]

Probably over safety conscious but if you’re refueling you should have the nozzle in contact with the wing to discharge any static build up, especially in cold dry air.

If you watch a tanker truck get top loaded they always have a long tube that goes down in the fuel to prevent that static build up.

Usually they bottom load though so it’s not an issue.

https://safetymeetingtopics.net/images/Toolbox_Topics/refuelingstatic.pdf

We really should bond the nozzle to the aircraft, Military does but I’ve not seen it in the Civilian world and as I assume refueling fires must be rare, I guess it’s a one in a million problem. But still any fuel company should know not to show something like that on the internet.

[hazek]

On 4/5/2025 at 4:52 PM, gabez said:

if you watch this video, around minute 19:00 you will see someone spraying the wing of the plane with a substance and wiping it (bottom right)

Great catch!

[Pinecone]

On 4/5/2025 at 8:24 PM, A64Pilot said:

We really should bond the nozzle to the aircraft, Military does but I’ve not seen it in the Civilian world and as I assume refueling fires must be rare, I guess it’s a one in a million problem. But still any fuel company should know not to show something like that on the internet.

If you hook up the ground cable, that should bond the nozzle to the aircraft.  The nozzle is bonded through a conductive element in the hose.

[gabez]

 

[mluvara]

1 hour ago, gabez said:

 

Same Cirrus that I reported on previously. It went to a Cirrus service center near Juan for inspection and repairs

 

[MikeOH]

Just now, mluvara said:

Same Cirrus that I reported on previously. It went to a Cirrus service center near Juan for inspection and repairs

 

Do you know if this G100UL problem instance has been reported to the FAA per their recent SAIB?

[mluvara]

2 minutes ago, MikeOH said:

Do you know if this G100UL problem instance has been reported to the FAA per their recent SAIB?

I shared the SAIB with the owner. The FAA FSDO did visit the aircraft onsite with Cirrus, so they are aware. If you note carefully in the SAIB, the notice was for FSDOs to report what they had learned too.

Edited April 8 by mluvara

[A64Pilot]

4 hours ago, Pinecone said:

If you hook up the ground cable, that should bond the nozzle to the aircraft.  The nozzle is bonded through a conductive element in the hose.

Should, if it has the wire in the hose like it should and the wire doesn’t have an open circuit, but also believe it or not but static builds from fuel falling in the air, that is why the tanker trucks that top load have the dip tube

https://www.chevronwithtechron.com/content/dam/external/chevron/en_us/marketing-support/all-other/Static_Electricity_Hazards_and_Prevention_from_CBT.pdf8v

https://docslib.org/doc/12963317/petroleum-loading-and-unloading-procedures-top-loading

As I said probably over cautious and when was the last time you heard of a GA aircraft catching fire being fueled, so probably not real necessary, but why not do a couple of things that require nothing special like be sure you touch the wing to dissipate static from you before you stick that nozzle in the tank?

I refuel inside of my hangar so I guess I’m overly paranoid.

But if you care when we refueled from a truck, (Military) the truck had to be grounded, the truck bonded to the aircraft and the nozzle bonded to the aircraft before being attached to the aircraft, we never open port refueled too, because of the danger from vapors, and that was Jet fuel which is harder to ignite than gasoline

Edited April 8 by A64Pilot

[redbaron1982]

4 hours ago, gabez said:

 

The most ironic thing about G100UL is that most likely is much worse for health and public safety than 100LL

Edited April 9 by redbaron1982

[IvanP]

4 hours ago, mluvara said:

Same Cirrus that I reported on previously. It went to a Cirrus service center near Juan for inspection and repairs

 

My guess is that George will now declare the Cirrus to be painted with "inadequate" paint system and "poorly maintained" which clearly caused the damage shown in the video . After all, well maintained planes that use "proper" paint are fine when G100UL is splashed around.    

Sarcasm off...

[mluvara]

Been awhile, but have an update on some aircraft (plus a new one), and interesting learnings from fuel selector bench testing.

 

 

[A64Pilot]

Pretty sad that it takes an interested citizen to do testing that the FAA should be doing.

What will it take to get them testing? If tests show negative results in one day, surely they are easily replicated?

I understand how Political pressure on any Government agency is enormous, I saw it and had to deal with its aftermath with the G-650 Certification crash, unfortunately they had to kill people in order for action to be taken.

Is that what it will take here, deaths?

[Pinecone]

GAMI did do testing of installed o-rings.  Plus running the fuel in a number of airplane for over 10 years.

[Sabremech]

Just now, Pinecone said:

GAMI did do testing of installed o-rings.  Plus running the fuel in a number of airplane for over 10 years.

So what’s the explanation now for the issues being observed? 

[MikeOH]

3 hours ago, A64Pilot said:

Pretty sad that it takes an interested citizen to do testing that the FAA should be doing.

What will it take to get them testing? If tests show negative results in one day, surely they are easily replicated?

I understand how Political pressure on any Government agency is enormous, I saw it and had to deal with its aftermath with the G-650 Certification crash, unfortunately they had to kill people in order for action to be taken.

Is that what it will take here, deaths?

In a word, "yes", people are going to die before the FAA rescinds their blanket STC.  As you point out, that's what it has taken in the past; this situation is no different.  Maybe even worse since the politics of "lead is EVIL" is likely more problematic than biz jets for the rich.

[A64Pilot]

3 hours ago, Pinecone said:

GAMI did do testing of installed o-rings.  Plus running the fuel in a number of airplane for over 10 years.

Leads one to question then what the scope of testing and field trials were then.

The relative sample of aircraft that are now burning the stuff is small, yet there are serious problems.

Is it something about California then? One or even two aircraft I could understand being outliers, there will always be a very few problems with anything new, bugs to work out etc. Try as you might to manufacture the perfect product usually something pops up once it’s out in the wild that didn’t show up in testing.

But there have been a slew of problems in a relatively small sample of aircraft, not just one or two bugs, but big seemingly unsolvable problems, the fuel selector valve issue on the twin Cessna is unquestionably a safety of flight issue. That could probably be fixed by Viton if it were part of the STC, but not every O-ring and or incompatible material can. I’ve not seen Viton seals for example, surely they exist. but Viton has a higher durometer than Buna-N will it cause wear on boost pump shafts for instance? What’s the basis of approval for substituting Viton for Buna-N in everything?

Apparently according to the Eagle fuel cell guy the fuel cells in my Mooney are made from Buna-N, if they swell by 60% if nothing else they won’t fit in the same size compartment, this will lead to I’m sure wrinkles, wrinkles trap water, I learned that in my C-210, engines won’t run on water obviously.

But just going off of a gut feeling without supporting data it’s my belief that anything that seriously causes materials to swell is degrading the material in some way.

This stuff eats two part polyurethane paint, the Army uses two part polyurethane paint as CARC paint, Chemical Agent Resistant Coating, anything that “eats” two part polyurethane paint is an aggressive solvent.

The varnish on the Bonanza’s dip stick would have been more than enough for me

Edited April 28 by A64Pilot

[Pinecone]

7 hours ago, Sabremech said:

So what’s the explanation now for the issues being observed? 

Not sure.  But it seems strange that GAMI did a lot of testing with no issues.

It is possible they were already on their last legs.

[Sabremech]

 

20 minutes ago, Pinecone said:

Not sure.  But it seems strange that GAMI did a lot of testing with no issues.

It is possible they were already on their last legs.

No issues that they admit. 

[EricJ]

1 hour ago, Pinecone said:

Not sure.  But it seems strange that GAMI did a lot of testing with no issues.

It's easy to not have issues when you're your own DER.

[ragedracer1977]

1 hour ago, Pinecone said:

Not sure.  But it seems strange that GAMI did a lot of testing with no issues.

It is possible they were already on their last legs.

If you’re referring to the video, they were literally brand new o rings

[EricJ]

8 minutes ago, ragedracer1977 said:

If you’re referring to the video, they were literally brand new o rings

Yes, after a one-day soak in G100UL in the fuel selector assembly the brand-new o-rings failed after only a few actuations.   If there was testing done at GAMI, it either didn't cover a common application like this or the results were not shared or included in their analysis.   Neither case is a good situation.

[A64Pilot]

I don’t believe they had all these issues and forged ahead.

Even if we assume he knew of the problems, he’s smart enough to know they would surface very quickly once the fuel hit the street.

Only way I could believe even a dishonest person would do such a thing is if they sold the rights etc right after obtaining the STC. Which of course didn’t happen, so I’m at a loss to explain.

‘I am not saying, implying etc that there is any dishonesty going on.

Only think I can come up with is that there is some kind of difference in the fuel being sold and the fuel that was tested, or some other difference in storage, environment etc.

Edited April 28 by A64Pilot

[ragedracer1977]

33 minutes ago, A64Pilot said:

 

Only think I can come up with is that there is some kind of difference in the fuel being sold and the fuel that was tested, or some other difference in storage, environment etc.

Or there wasn’t near as much testing as you were led to believe.

 Alternatively, as stated here by George himself, nitrile shouldn’t be in airplanes anymore anyway because there’s a service bulletin from 1980 something.  
 

I honestly think this is a case of not knowing what you didn’t know. He has some crazy ideas about what you can and can’t do with airplane maintenance.

[A64Pilot]

I retired from the Army in 2003, the Army and I assume all services seem to adopt the latest and greatest processes and materials, for instance we were using teflon hoses when I first came in in 1982, replaced 5606 with 83282 etc.

‘As of when I retired even the then new AH-64D still used Buna-N O-rings throughout. I first used Viton in cave diving in I guess 2105 or so, never seen it used in Aviation until I saw some crop duster gate box seals that were Viton, and that has nothing to do with aircraft engines etc, I’m sure Pratt & Whitney still used Buna-N as of five years ago.

I think Viton’s use in aviation is rare from my experience.