Rep. Jay Obernolte On Fielding Unleaded Fuels


The FAA’s 2023 Reauthorization Bill hit a snag when language in the bill appeared to require airports to continue selling 100LL gasoline. California Rep. Jay Obernolte explains to AVweb’s Paul Bertorelli how an amendment fixed the problem.


  1. I use AI in programming daily (via GitHub CoPilot, which is using OpenAI technology as does ChatGPT). I can type a comment in my development tool (Visual Studio), and CoPilot will suggest some code. Usually is scary accurate. Sometimes it misses completely. Most of the time as I’m working it will “auto-complete” programming. Frequently finishing something is an exercise in [tab][tab][tab] done. In all cases the programmer must verify what the AI has suggested is what they want. It’s not a risk if you’re doing proper development work. It is a real timesaver and has often come up with something better than what I would have done on my own. It’s not the scary monster people make it out to be. [Some programmers on the other hand should step away from the keyboard and can write junk all by themselves.]

    Regarding fuel, I’d love to see the FAA just buy George out and put G100UL in the public domain. The FAA has already approved it for all airframes and all spark-ignition engines. The technical problem is solved. The rest is bureaucratic nonsense. As I understand it, it took him 90 days to find a fuel the PAFI process hasn’t been able to find in *20 years*.

  2. Thank you, Paul, for the video. I found it very informative. It is refreshing to see someone in Congress that is an experienced pilot and seems to actually care about aviation beyond the airlines. While I appreciate Rep. Obernolte’s explanation of why he inserted the amendment worded the way it was, I kind of question whether it fixes the problem of GAMI’s replacement fuel. He seems to kind of talk in circles about a “consensus” standard fuel. The FAA has approved G100UL for all spark ignition engines in the fleet, which sounds like a pretty good consensus, but yet the way the amendment is worded, it sounds like it would have to be an ASTM “consensus” to actually qualify.

    On a slightly different subject, perhaps soon you could do one of your video presentations explaining just how the ASTM process actually works. Who applies for the specification and what is involved in getting it approved? And just who is the American Society of Testing and Materials? I can’t seem to find any information about how that whole process works. I do know that George Braley did not go for ASTM review and approval due to concerns over confidentiality of GAMI’s formulation, but he did not explain what that actually meant. Judging from some of the comments I have read on Avweb articles about unleaded avgas, it is obvious there are a whole lot of readers who don’t seem to know much about it either. Thanks in advance, if you decide to take on that challenge.

    • Paul, John Mc makes a good point. Like an explanation of key points covered by ASTM D910 on the specifications and requirements for G100UL.

  3. Good discussion of the FAA Re-authorization bill’s amendments, Paul. Nice to see a congressman who understands aviation involved in this complicated legislative process.

    This whole “industry consensus” thing is confusing and uncertain. From what I gather, it takes a long time for ASTM approval of pretty much anything due to the need for so much testing.

    Since the FAA has already approved the STC for GAMI’s G100UL, wouldn’t it be much quicker and simpler for the FAA to declare G100UL a “consensus” fuel and approve it without the STC restriction for all piston engines? I realize that would have a big financial impact on GAMI but the important goal here is to distribute 100UL fuel widely as soon as possible. Other 100UL fuels that are in development could then go the ASTM route while G100UL becomes available to all airports. Any 100UL fuel approved by ASTM would have to be capable of blending with G100UL to allow airports to buy any 100UL fuel for single tanks, pumps or trucks just like they do with 100LL.

    • Actually, in this context, ASTM does no testing itself. It reviews the technical data and literature used in the FAA-approved testing, delves into manufacturing issues and may ask for additional data. I think that might include more testing for the candidate, but not by ASTM itself. Members of the organization then vote through a series of ballots to approve a standard. The flaw is conflict of interest. Companies you may be competing against are also the ones voting on approval of your spec.

      This explains the process:

  4. Paul, John Mc makes a good point. Like an explanation of key points covered by ASTM D910 on the specifications and requirements for G100UL.

  5. The argument against allowing an STC’ed fuel to replace 100LL because it’s not “freely available” to any one wanting to use it at least is a valid argument. I think it’s an unnecessary and short-sighted argument, but I can at least accept it.

    My question is, do you actually have to provide an STC number for any pump to dispense G100UL (or any other STC’ed fuel, for that matter)? Or is it just a matter of legality that you’re not supposed to be burning a fuel that you haven’t purchased an STC for?

    Te other part of the “STC 100LL replacement” argument that I could see is what happens if a pilot lands at an airport with minimum fuel only to find the only fuel available is an STC’ed fuel that they don’t have an STC for. Do they have to take off and hope they can get to an airport with 100LL before running out of fuel, or is there some way to pump G100UL without an STC in an “emergency” situation?

  6. Maybe a solution to the STC issue would be that any FBO that sells only G100UL is also authorized to issue the STC on the spot. Fill out the form, pay the fee and you are now signed up and legal. Since there are no modifications needed to either the airframe or engine, this is basically just a paperwork exercise. As far as payment is concerned, you just charge it on the same credit card you use for buying the fuel. As I have said before, the FAA allowing G100UL to be used in ANY spark ignition engine currently in the fleet, sounds a lot like a “consensus” standard to me. Some people may interpret that consensus means an ASTM specification, but the law does not say that.

  7. We seem to have a “chicken or the egg” problem. My aircraft will qualify for the STC for GAMI fuel, but since nowhere that I fly is it currently available, I am reluctant to spend money on the STC when it will do me no good. I like the John Mc solution for an onsite STC purchase at airports that sell G100UL fuel. At that point, there is no reason for an airport to not sell G100UL fuel. How about it, George Braley? He could fix this problem immediately. Either that or as someone suggested, simply sell his STC to a major fuel company or the FAA. Mr. Braley is not going to live forever – so this is an opportunity to cash out now rather than incrementally via the individual STC route…