George Braly, co-founder of General Aviation Modifications, Inc. (GAMI) presented a forum at Sun ‘n Fun 2025 today on his efforts to bring GAMI’s G100UL unleaded avgas to market. Braly expanded on remarks he shared with AVWeb yesterday in a podcast on the topic.
“He said it’s likely the sealant was either poorly applied at the factory decades ago or improperly resealed over the years.” Yeah, and G100UL exposed that fact by causing leaks today that expose that poor application from years past. Where is the logic here?
1960 aircraft; started a fuel weep a few years back; on 100LL
Emptied the tank; sealant had disintegrated into very fine sandlike material.
Replaced parts and sealant; problem solved.
Engines on unleaded fuel last longer and have fewer problems; Proven Fact!
GAMI fuel has had more testing than current fuels; it is more consistent.
The nonsensical resistance to moving forward is simply greed;
100LL is extremely profitable; current producers don’t want to give that up.
US Lawyers are the other problem; any change is an excuse for time consuming profitable for lawyers lawsuits.
The unjustified resistance to change by US manufacturers is nothing more nor less than fear of litigation.
Randy said “Where’s the logic here?”
Do you really think those blue stains in the picture at the top of the article were there from BEFORE the 100LL leak was repaired in 2015, TEN years ago? Unlikely that it was left on the aircraft after the repair: you’d want a clean surface so you could tell if the new repair was leaking or not.
The logic here, Randy, is that the tanks were leaking all along, but until all the hot air about G100UL “causing leaks,” the owner/operators weren’t looking for them. Upon finding them, they jumped to the inappropriate conclusion that G100UL caused it. G100UL doesn’t cause blue stains.
Braly has not only invented a new unleaded fuel, but also an excellent fuel leak detecting agent. Additionally, it has the effect of motivating aircraft owners to have their fuel system leaks repaired as rapidly as possible to protect their paint. This will also help our local mechanics stay in business repairing all the fuel leaks, not to mention the aircraft paint shops. What’s not to like about G100UL?
Just throw some tariffs on the fuel, the stains, the sealant, the IP thieves, the exhaust valves and guides, the paint… even on the FAA and the
ASTM committee, throw them on everything because that’ll fix it, no worries mate, all sorted! I’m sure that’s what the village Idiot in the Capitol will prescribe 
Good luck getting any funds for this little project once Elon finds out what you’re trying to achieve! (For the ‘sticks in the mud’ out there… it’s just a bit of light humour ;))
If the stains were blue, that would point to the blue fuel, i.e. 100LL, as the source, not G100UL, which is not blue.
There are both colors of stains in the photo
In defense of GAMI & George Braly, his concern about IP theft is valid. In the 1980s, our group wrote an FAA/DOT Small Business Innovation Research proposal to develop a “Airborne Weather Information Dissemination System” which we called AWIDS. It was based on a new and very realistic computer generated voice just marketed by Digital Equipment Corp. The proposal was rejected and less than 3 months later, Lockheed Martin was award a much bigger contract for a “novel weather broadcasting system called AWOS.” His concern is valid with ASTM and his formulations and variations should be protectable by patent. The reality is it can be determined by analytical chemical methods which is the other 2/3 of the equation.
It’s too bad people don’t take before and after pictures; then it would be possible to make more valid inferences.
Not really necessary in this case, since the blue stain was clearly “before”.
It’s actually not valid. I know the story behind this misrepresentation of the facts in respect to the ASTM committee and the oil company, but can’t divulge them here.
Powerful points.
As Braley is a lawyer, I expect his claim about a patent attempt was not just off the cuff in the spur of a moment.
(George Braley is an engineer and lawyer. What capability do his flapping detractors have?)
My experience with industry standard committees is they are cumbersome, sometimes not thinking clearly and broadly, and used by some participants to block innovation so their own products will have more sales.
Braley and IIRC Swift have detailed gaps in the ASTM avgas standard, and recommended additions to improve effectiveness of the standard.
Let’s assume that G100UL is the ‘standard’ moving forward. Does Braly have the manufacturing resources to produce enough fuel to meet the current demand? Is this fuel going to be made available to everyone, or will you still need a STC? ( I believe this is a colorful sticker one applies around the fuel filler ). If this is a drop in replacement, why is it even necessary to have a STC?
Sorry Charlie, but I don’t believe we have all the facts here.
This topic was automatically closed after 7 days. New replies are no longer allowed.