Unleaded 100-octane aviation fuel should be available at three California airports as early as this summer, according to officials with General Aviation Modifications Inc. (GAMI).
In an hour-long, standing-room-only forum at the 2023 SUN ‘n FUN Aerospace Expo presented by GAMI’s George Braly, he noted that — if all goes according to plan — Reid-Hillview Airport of Santa Clara County (KRHV), Watsonville Municipal Airport (KWVI), and Meadows Field Airport (KBFL) in Bakersfield will be the first airports in the country to offer GAMI’s lead-free 100 octane FAA-approved avgas known as G100UL.
A California FBO chain also has expressed interest in distributing the new fuel at its 13 locations, he noted.
“California is crying for this fuel,” said Braly. “The avgas situation at the Reid-Hillview airport is critical because the sale of 100LL has already been suspended there.”
As a sad result, Braly said that a plane reportedly ran out of fuel and crashed when its owner attempted to fly from Reid-Hillview to a nearby airport for a fill-up. The plane’s fuel had been depleted by extended engine run-ups at a maintenance shop.
After a 13-year effort and many roadblocks, GAMI finally received its all-inclusive STC in September 2022. During the SUN ‘n FUN forum, Braly praised the efforts of the FAA certification staff in the Wichita office. He also cited help at critical junctures from now retired Senator James Inhofe and Mark Baker, president of the Aircraft Owners and Pilots Association (AOPA).
In order to buy and use the new environmentally friendly fuel which, appropriately enough, is green in color, aircraft owners are required to purchase an STC from GAMI. The STC costs around $2 per horsepower and includes placards and a flight manual supplement.
More than 500 STCs have been sold so far, according to GAMI officials.
As a drop-in fleet-wide avgas replacement, G100UL can be mixed with 100LL in any ratio and without any alteration to aircraft engines or airframes, GAMI officials added.
GAMI is currently working with an experienced aviation fuel blender in Houston that can produce the patented formulation in railcar quantities by the end of June 2023. After the shipment of G100UL arrives in California, the fuel will be loaded into tanker trucks and delivered to individual airports.
Avfuel, a global supplier of aviation fuel, helped GAMI fund the STC process over the past six years, but any qualified aviation fuel producer or blender can apply for a license to produce and distribute G100UL.
“That creates competition,” said Braly, who hopes to have nationwide distribution in place by 2026. “It’s a chicken and egg situation.”
The new avgas has been thoroughly tested since 2010, when it was first flown in GAMI’s turbo-normalized Cirrus SR-22. In addition, Braly reported that the Cirrus Aircraft factory in Duluth, Minnesota, conducted a series of independent and well-documented test flights last winter that compared and graphed the differences between 100LL and G100UL.
Braly reported that Cirrus confirmed his earlier experiments showing that GAMI’s unleaded avgas produces a 4% improvement in Brake Horsepower (BHp) at the same lean of peak (LOP) fuel flow. In the example cited, G100UL produced almost 10 horsepower more than 100LL.
“The science works folks,” said Braly. “The tests done by Cirrus were an elegant experimental ratification of earlier test data.”
Braly was also quick to point out that having more energy available from G100UL makes up for the fact that it weighs slightly more than 100LL and is likely to cost more.
During testing observed by FAA officials, detonation protection from using G100UL exceeded that of 100LL, Braly reported.
In addition, Embry-Riddle Aeronautical University helped GAMI conduct a successful 200-hour engine durability test using a relatively high time (1,400 hours) engine. Robinson Helicopter is also about to start its own independent evaluation of G100UL.
Other tests have shown that GAMI’s avgas does not harm fuel tanks made of fiberglass and carbon fiber. Also, a batch of G100UL that had been stored in a drum for 12 years still met specifications, Braly noted.
Other unleaded 100 octane aviation fuels are in the testing process, including those from Swift Fuels, Lyondell and VP Racing, and Phillips 66 and Afton Chemical.
You can learn more about G100UL at G100UL.com. You can learn more about the FAA’s unleaded fuel initiatives at FAA.gov/Unleaded.
How do you prevent the use of G100UL by those that have not wasted money on the STC? Are you going to have personnel standing by each fuel tank to ensure an STC placard is in place? Are you going to impose extremely heavy fines if caught “getting fuel from the wrong tank”? If I take my plane to fuel up at midnight, with there be a guard looking over these fuel tanks?
I understand wanting to recoup your investment costs but that is what government grants are for when it is the government mandating this to be done. Or, do like any other inventor does and demand royalties in perpetuity. And why attach a “per horsepower” cost to the STC? Why not a simple flat rate since there is nothing actually done to the aircraft or engine other than placing a sticker on the wing?
Doing it this way only encourages people to ignore the STC costs and ignore the fuel (since it will most certainly be significantly more costly) until it is mainstream where they will simply put it in the tanks anyway. This STC is silly.
When modifications to an aircraft or aircraft engine are accomplished, subsequent test flights are always accomplished with heightened awareness around operational excursions from the norm. It will be vital for the flying public to consider any new fuel a “modification” and any new anomaly a matter of concern. Vigilance will pay off in this area.
A sidebar comment: Compression ratios are not the only reason for using higher octane fuels. As indicated, boosted operation and high-altitude heat concerns are certainly relevant. But engines using large diameter combustion chambers in excess of 5.5 inches also need slow-burning, high-octane fuels to avoid pre-ignition and detonation, regardless of compression ratio.
I am a mechanic with 55 years experience working with a client base average of 100 aircraft. About 85% have been using mo-gas since the seventies. I have had less maintenance problems with the mo-gas users than the 100LL av gas users over thousands of hours of use. The engine compression ratio’s range from 5.5 to 8.5 that originally where certified on octane ranges from 65 to 96. Most octane ranges have a low to high ( 90/96 for instance) which means it is safe to run anywhere in that range. Originally, some of the old fighter aircraft that had internal superchargers ,and turbos needed some help with the higher 130 octane ( purple fuel) and then some used the 96 octane (green fuel) and some used the 80 octane (red) fuel. Then somebody got the brilliant idea to quit making all those different octane fuels and eliminate the red, green and purple fuels and make one combined for all seasons fuel called 100LL, and color it blue. That fuel has a little less lead than the 130, but more than the 80/96 fuels did. Now, why can’t the powers that be get off the band wagon, and go into the Type Certificates, approve the fuels that have thousands and thousands of hours of proof
and eliminate all this STC stuff that no one is too likely to enforce anyway. Oh wait, I know, it is called MONEY and pay-offs to the policy makers.
Wow, that’s quite a list of ‘Villains’ that Mr. Prukop has assembled!
“Just because you’re paranoid doesn’t mean they aren’t after you.” attributed to several sources.
Here’s just ONE of those NGO’s AKA ‘Villains’ working against you, me and everyone else. Listen carefully: https://www.youtube.com/watch?v=teg5CJhSwy0&t=71
All of the Klaus Schwab/WEF schemes and those of the United Nations Agenda 21 and Agenda 2030 with their “public-private partnerships” dovetail together and are wholly Fascist in nature.
For more insight, check https://abeldanger.blogspot.com from time to time and especially review the videos in the “Is it Live or Is It Livery?” section. Here’s a link to make it a breeze: https://abeldanger.blogspot.com/p/videos.html
Good luck!
Wait! If there are no changes to be made to your aircraft and it’s a “drop in replacement,” what’s the STC for? Do you need to show your STC before buying the fuel?
During SnF I spoke with a vendor (I dont remember which bender but it was not GAMI) about how I feel excited about how the new fuel will help with maintenance cost increase in performance. This vendor stated that GAMI has noticed problems with fuel lines degrading because of the new fuel but has failed to mention that to people who buy the new fuel and STC. I question the validity of the statement by the vendor and doubt that GAMI or anyone else would allow a fuel that causes harm. It’s a shame that a vendor would try to harm the reputation of a highly respected company. I for one have not heard of any fuel line issues. I wonder if anyone else heard anything about this. I look forward to getting the STC personally when the fuel is available on the east coast.
Does anyone actually BELIEVE that Santa Monica is not going to find some other excuse to ban airplanes from that airport? They want that property for development, tax revenue and the kickbacks from the developers. Get real folks.
It’s convenient for “somebody” that an STC to use G100UL costs $200 for the owner of a C150, and that the cost is based on an engine’s horsepower! What’s that all about? If I had a C182, my STC costs $220 more?
The next step is to make the unleaded avgas renewable.
Since all gasoline is a mix of hydrocarbon octane, heptane, toluene, xylene, etc. it isn’t easily made from other hydrocarbons, like cellulose, C6H10O5.
Shell makes gasoline and motor oil from nat gas, with a modified Fischer-Tropisch process. It can also use coal as an input, which the USA has about 100 years of supply, and is now much less used to produce electricity, [ maybe a good thing with the emissions of heavy metals, and uranium ].
So, possibly ‘renewable’ methods….??
Another get rich scheme WITHOUT ANY ARTICULABLE OR PROVABLE INTRINSIC/EXTRINSIC EVIDENCE whatsoever that existing Blue 100 Low Lead Avgas has caused harm to ANYONE, let alone “THE CHILDREN!” But it’s just jolly for the money pump and dump lying global-warming-climate-change-Dollar-carbon-foot-print-Tax-promoting-healthful-carbon dioxide-denying UN Master Manipulator’s who run the integrated global plantation SCHEME from various NGO (Non-Governmental Organization) “THINK TANKS” that are SELected and UNelected and UNaccountable to anyone via their United Nations machinations like UNESCO *(United Nations Environmental Scientific Cultural Organization) and the UN-IMF *(United Nations International Monetary Fund) who promote “SAVING THE EARTH” under various pseudo-science schemes and rubrics that were initiated under AGENDA 21 during the 1992 UNCED Earth Summit gathering “IN OUR HANDS” *(United Nations Conference on Environment and Development), now enhanced under AGENDA 2030 including integration of the full surveillance and repressive control mechanisms of AI *(Artificial Intelligence) and financial extraction schemes. ALL ARE TOXIC FOREIGN ENTITIES THAT DO NOT ADHERE TO THE U.S. CONSTITUTION OR THE LAWS MADE IN PURSUANCE THEREOF.
You can read what the UN-IMF has planned for you: “GLOBAL POLICY AGENDA 2023 – And Beyond” and “WORLD ECONOMIC OUTLOOK” here: https://www.imf.org/en/Publications
GET THE UN OUT OF THE USA NOW!
If you actually fly a piston engined aircraft, you would know the HARM that TEL and Lead-dibromide does to the engine…fouls spark plugs, contaminates the oil with lead compounds and causes stuck exhaust valves after some time.
So I for one am glad to see 100LL gone and G100UL in its place.!!
No agenda 21, just some great fuels engineering..!!
Awesome. Kudos George. It’s about time this happened.
These airports could have had unleaded aviation fuel years ago but refused to offer it. I and a few others helped find them a supplier of lead-free, ethanol-free, high AKI rating mogas, which also would have cost far less than 100LL and any of its boutique fuel replacements. But it was all-or-nothing for them, despite mogas being a perfectly adequate and legal, FAA-approved aviation fuel that would have been fine for at least 70% of the aircraft based there. American airport management is so backwards, probably because most are run by the government. I have little sympathy for the aircraft owners that now face the consequences of apathy.
Thank you Mr. Braly!