Technically speaking…

The quest to find some answers at Oshkosh

In my last post, I had the gall to be less than positive about things at the Oshkosh airshow. I was surprised at the positive feedback about similar experiences. However, our publisher, Ben Sclair commented that to see Oshkosh through the eyes of a new aviation enthusiast is like a kid on Christmas morning — it is one of the greatest experiences ever (A suggestion for keeping the magic of AirVenture alive) And he is absolutely 100% correct.

But where are they going to find 500,000 new aviation enthusiasts every year? Since they are not available, they are going to have to depend on repeat visitors. And why do pilots return to Oshkosh, pay for their transportation, fight large crowds, and pay $250 dollars for a small hotel room? Well, most of us do it to learn what is new and to get answers to our many technical questions.

In the past, companies like Lycoming had a technical booth to answer such questions. And if you walked by it, you would see our friend, Paul McBride, who writes the Ask Paul in General Aviation News, and others, sit for eight hours every day during the show and answer questions. There were usually a dozen or more people waiting to see them and when you finally got your turn, Paul could answer almost any question and would usually have a service bulletin that addressed your concern. If he did not have the answer, he would take your name and address and tell you he would look into it. Now here is the amazing part that many people will not believe, but he would actually get back to you.

Before every AirVenture, I go through my old e-mails, and look at my files to make a list of questions I would like answers to. To give you an idea of how that went this year, let me share a few examples.

One of my first stops was at an LSA engine manufacturer. I went in and identified myself as being from General Aviation News and said I wanted to talk to one of their technical representatives. I was directed to a gentleman who was talking to several men in another part of the exhibit. I went over and waited until the “expert” answered their question. He then turned to me and asked if I had any questions. I again identified myself and explained that I had received numerous questions concerning their octane recommendations.

He informed me that they had done a lot of research and found that as long as a fuel has a Research Octane Number of 95 or more it will work in their engines. I then explained that no one in the U.S. can find the Research Octane Number of the auto gas they are buying because the oil companies only report the R+M/2 or anti-knock index (AKI) number, and that they would greatly reduce the confusion if they would change their spec to a number that people can actually find. The conversation went downhill fast.

One of the main lessons they teach at “expert” school is the principle of pretentious certainty. What this is concerns what to do if, as an “expert,” you do not know the answer, if you just repeat your guess loud enough and with enough positive feeling, most people will take your answer as the truth. So this “expert” got fairly loud and started in by saying that the Motor, Lean, and Rich octane numbers and the AKI are all meaningless and that the only number that means anything is the Research Octane Number. He went on, but I could not think of any intelligent thing to say that he might understand so I decided to try another company.

I walked up to another LSA engine supplier. Again I identified myself and asked if they had a technical expert. He said that he could handle that. So I asked him, since they had approved ethanol-containing fuels, how did the engine compensate for the lower stoichemetric value of the ethanol-containing fuel. He said that it was all automatic. I asked if they had an O2 exhaust sensor or some other means to change the mixture strength. He said no, and then showed me the carburetor and said the metering rod goes up and down to change the mixture strength as needed. I then pointed out that it appears that they have a constant vacuum carb and that it changes the mixture based only on air flow and not the heat content of the fuel. He walked away.

Well, maybe the airframe manufacturers are better informed. I then went out to the Cessna booth to look at the new diesel-powered NXT (now known as the Turbo Skylane JT-A). I again asked for a technical expert and went over to talk to him. My first question was what kind of identification they were going to add and what type of a fuel receptacle they were going to use to ensure that 100LL is not put in the aircraft. For example, were they going to use the BP-developed fueling door? Have you ever seen someone with that deer in the headlights look? From his look, I knew it was time for me to put my question list away and go shop for T-shirts.

Now this column is not a criticism of the Experimental Aircraft Association (EAA). The problem here is companies that send salespeople instead of technical people to the airshow because they think sales are more important than technical service. They may also think that if a technical person speaks the truth it may reflect badly on their corporate image. Some companies do not understand that good, honest information about their products is absolutely critical to their continued operation in the aviation business. If they can’t set a simple octane spec that people can follow or provide honest answers about their products, then they are inviting lawsuits.


Ben Visser is an aviation fuels and lubricants expert who spent 33 years with Shell Oil. He has been a private pilot since 1985. You can contact him at

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