Model T of the air, Part #2 – Leeon Davis notes


I mentioned Leeon Davis in the first part of this story. There is not much biographical information on him on the web, but I found this link below , It has a good short summary of his designs:

Above, Rex Johnston’s Corvair powered DA-2

There are long articles on the DA-11 and the DA-9 in back issues of Contact! magazine. A long time ago in the 1990s, Sport Aviation did a story on the DA-9. At 375 pounds, powered by a C-90 Continental turning high rpm, it would do 290mph, an impressive special purpose missile.

There have been several Corvair powered DA-2’s. The best known one is Jim Ballew’s in Oklahoma. It has about 500 hours on it. Jim also has a Corvair powered 601 and a Corvair powered Pietenpol. There are links to all three at this story:  Another new “Zenvair” 601XLB, Jim Ballew, 2700cc

Rex Johnston’s DA-2 is a story that gets a lot of attention on our website, because his plane is the first Corvair powered plane with Electronic Fuel Injection. In the 20 years I have been teaching people about Corvair engines, I have had many people tell me that they were going to do this, but Rex was the guy with the combination of skills and persistence. You can read about it at this link:  Corvair Powered Davis DA-2, w/EFI

In part one, I said that Leeon Davis was the most outspoken proponent of mass-produced aircraft at an affordable price. His hall marks were light weight and extreme simplicity. Today, it is very hard to imagine how against the grain this was in the 1988-94 time line. The ‘Fast Glass’ rage was on, and many new high-end designs came out that got a lot of attention, even when they were not particularly good designs.  (Prescott Pusher and the Cirrus VK-30 come to mind here). You can read my story 2,500 words about levels of aircraft finsh…… to get an inside look at how these aircraft distorted the world of homebuilding and aviation journalism.

Davis was sending out the message of simplicity, just when few people were listening, as the magazines began to focus on planes that reflected the “conspicuous consumption” mentality. One of the real differences of that era was also a reflection of a change in society. People willing to heavily finance their hobby on credit. Previous to this people took out loans for houses and cars, but not often homebuilts. If you read the magazines of the 1960s, it is very clear that people built from savings or paid for the plane in parts as the made progress.  Kit aircraft go all the way back to Bernard Pietenpol and Ed Heath, but the explosion of kitbuilding only came after the 1980’s provided an accumulation of wealth and the willingness to spend even more. A great number of the high end planes of the 1990s were financed by an outfit called Green Tree financial. They had previously specialized in financing mobile homes, but moved heavily into boats , motorcycles and planes in the 1990s. If you read their history, it is filled with all the buzz words we learned in 2008 like “securitized loan packaging”. This new availability of money to loan, the national mood to accept debt and the glowing coverage high end planes received put Davis’s message of realism off the radar. Look back, it is easy to see that the three factors above sold a lot of kits, but few of them were completed, and many of the people who did would have been happier listening to Leeon’s perspective.

I don’t want to imply that just composite builders were getting lost in this either; Look how quickly beautifully simple ultralights all became complicated. Same with metal aircraft, and fabric ones. All attention was all focused on the most elaborate machines. Very few articles ever said how much the airplane weighed or cost, two elements that Davis focused on. A lancair 320 called ‘dream catcher’ and a Pacer named ‘miss pearl’ come to mind as two planes that got a lot of press coverage for their detail paint and interior, but were each very heavy examples of their respective designs. The EZ’s built to Rutans specified simplicity and planes like Dave Anders 900 pound RV-4 didn’t get anywhere near the attention.

In 1998, I came very close to buying the design rights and tooling for the DA-2, but found the owner (not Leeon) a hard guy to deal with. I didn’t consider it a perfect plane, but felt that it was a good starting point. I spent a lot of time with Gus Warren and a set of drawings, and we looked at blind rivets, a different wing planform and a thicker airfoil. Once we agreed on a value, the owner specified that he would only accept payment in a form that the IRS and his ex couldn’t track. That was the derailment, not the design.

In the past 25 years, the qualities I like in planes and find important have evolved. You can read about more about this at this story: Steel tube fuselages, “Safe” planes and 250mph accidents . Before I knew how to fly I was captivated by slow landing Stol planes, because I incorrectly thought they would be easy to fly. Likewise I was initially following ‘stall proof’ planes until an instructor made me do an hours worth of stalls from every angle and approach, and then explained that flight qualities before and after stall are more important. I learned that many textbook/hangar flying ‘truths’ , like a 23012 having a ‘dangerous stall’ are a myth.

A point I would like to make is that I liked Davis’s values as a designer, even if his aircraft were not the best ones for myself. We could ask Jim Ballew if he likes flying his 601XL more than his DA-2. He might, especially if he was flying out of a short strip. I can make a case that a Panther would radically out perform a DA-5 on the same power. Davis went to extreme measures to save weight, and his planes have short spans and very little wing area. probably a reflection of flying from flat areas of the country and paved strips. Yet I can make a very good case that both the 601XL and the Panther have a great allegiance to simplicity. Chris Heintz and Dan Weseman moved slightly off stone simple to add a lot of capability to their planes, but they didn’t lose sight of the concept of affordability.

People who have never met me or just glanced at something I wrote may think of me as opinionated. But if you ask people who have known me for a long time, they will tell you that my perspectives evolved in the long run. I have always been interested in the results of a test, to see if a direction shift was in order. I have always listened to people with experience to learn from them. I am more likely to look for an indication I am wrong than a validation I am right. Today I have a refined and focused set of things that are important to me in aviation. If things go well, I have 20-25 flying seasons left, and I want to spend them on things I like, not what I ‘should be doing.’ I have a pretty good set of answers for myself, but they were not the ones I started with. I don’t need people to agree with mine, the point is only to find your own. The one thing that has not changed in my perspective is the thing I learned from Leeon Davis: simplicity and lower cost will always be vital characteristics. -ww

About William Wynne
I have been continuously building, testing and flying Corvair engines since 1989. Information, parts and components that we developed and tested are now flying on several hundred Corvair powered aircraft. I earned a Bachelor of Science in Professional Aeronautics and an A&P license from Embry-Riddle Aeronautical University, and have a proven 20 year track record of effectively teaching homebuilders how to create and fly their own Corvair powered planes. Much of this is chronicled at and in more than 50 magazine articles.

5 Responses to Model T of the air, Part #2 – Leeon Davis notes

  1. Bruce Culver says:

    I remember this from the first time you posted it. It reminds of another of your posts in which you mention that if the average price of entry level homebuilt kits came down a certain percent (I think it was 10%, but it may well have been higher), the number of people who could consider buying a kit and building an airplane would not increase by 50% but by a factor of perhaps 10:1 or more, because so many people out here were just below the financial entry point for homebuilt aviation. Keep up the good work…..

  2. Jim waterman San Antonio says:

    Have the DA-7 for several years now, was fortunate to work with Leeon until his death, have last plane we were building at that time, can provide Leeon anecdotes
    Jim Waterman

  3. Charise Daniels says:

    Leeon Davis is my father. Glad to see things about him available online. Jim Waterman could tell you a lot more about my dad and his planes than I could. My mother could also give you biographical info if you want.

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