Two very different Outcomes: Choose your own path.


Here are two polar opposite stories, two builders of Corvair powered planes, who had radically different outcomes on their first flight this week. The difference in outcomes is solely attributable to decisions the builders made. If you disagree, and  think the difference is that some people are ‘lucky’, let me strongly urge you to get out of aviation, now while you are still ok.


Success: Andy Mechling’s 3.0L Corvair powered Zenith 750 Cruiser. 

Andy called Dan and gave him a run down on the first two flights, both went very well, and he was showing real performance numbers like 110+ mph as a cruise setting with no wheel pats, larger tires and a climb prop setting. Engine was cool with a STOL Bowl , and everything is going very well. Satisfied builder at the beginning of many fine adventures.



Above: Get a good look at Andy’s expression the minute his engine fired up on the run stand at a 2016 finishing School we held at SPA. Read the full story here: Zenith 750 engine; Andy Mechling’s 3,000cc/120HP Corvair




Not Success: Pietenpol completed by a man who elected not to talk with me about his project crashes on its first ‘flight’:


First, let me say I’m very thankful that the guy wasn’t seriously hurt or killed. The investigators today said he was doused in fuel, and it was something of a miracle he wasn’t killed. Much of the following info I share isn’t speculation, it is from the actual investigators. Additionally, the first flight was captured on video,a more reliable source than personal recollections.


On June 20th, I wrote the following story on my blog, and yes this is the same aircraft: Need Help Contacting the Builder of this Aircraft ASAP. I wrote it because I was interested in speaking with the builder before he went flying and something went wrong. He contacted me the next day, and said I have to take his airplanes picture off my site, and off FB, as it was ‘Copywritten’ I wasn’t into debating it, my goal was to get him to reconsider some things I saw, even though he was not a builder of mine, and he never bought anything from me. The guy who sold him the project told him it was a WW conversion, it wasn’t, I didn’t care, just wanted to start a conversation with the guy to get him to reconsider some stuff. He wasn’t belligerent, but he wasn’t interested in talking. I’m a very serious respecter of personal choice, and it was his absolute right to make that decision. In the last few days some people on the net, with an axe to grind, have implied that no one tried to assist this man. That is complete BS, I did.


The plane tried to take off from a 4,900′ paved runway. That is at least ten times longer than a Pietenpol would need to get airborne from. It never gaining tree top altitude, but the pilot apparently never pulled the power back.  The plane flew another 1/2 mile, was not going to clear a line of trees, and the pilot tried landing in a rough field. The planes wing was completely displaced on contact with the ground, the fuel tank ruptured, and the plane was destroyed.


I have no idea if he read this 2016 story, but there is a reason why I selected it as story topic number one in the series.Critical Understanding #1, Take off distance.. If a pilot didn’t want to have this accident, all he had to do was pull the throttle back when he passed say 800′ and was still on the ground. Anyone who has seen Corvair powered Pietenpols taking off at Brodhead can see they only need 300-500′ for a modest regular takeoff. Still holding the throttle in thousands of feet down the runway isn’t a mechanical problem, it is a judgement error.  Any pilot, in any plane, who pushes the throttle forward without knowing his exact abort point on the runway, is making a judgement error, even if he never has an issue. The error is starting a takeoff with no plan. If you have been around homebuilding for a number of years, it is stunning how often this becomes a ‘first flight’ accident.


If you have not seen the series, they are all listed right here: Critical Understanding Reference Page. My commitment to assisting builders starts with the things I write and teach. It extends all the way to trying to contact people who are not even customers of mine.


The investigators mentioned that the plane likely had a home made prop on it, and that it never made full static rpm. I addressed both of these issues in this story: Critical Understanding #2, Absolute Minimum Static RPM.,  spelling out that no Corvair powered plane should ever be flown with less than 2700 static rpm.  Let me be very clear, it obviously wasn’t making anywhere near the level of thrust that even a very modest running Corvair turning a factory made prop would have. Included in the story is this sentence:

“No offense to any builder who wants to make his own Piet prop, but you have to look at what you are getting over a Warp Drive prop besides looks”


I’m going to spell this out for new people: I could put a 66″ long 2 x 6 on the front of a Corvair and it would turn 2700 static rpm, but it would make Zero thrust, it would not even allow the plane to taxi at 2 mph. That is a ‘safe’ home made prop. I could put a 66″long Warp Drive prop on the same plane and it would 2700 rpm, and fly great, because it would make about 400 pounds of thrust. The trouble with many home made or small company props is they may make the required rpm, but that is no indication what so ever that they make enough thrust. They may make just enough to get the plane in trouble. I have written countless stories about this, like this one: Critical Understanding #3, Rate of Climb, the critical prop evaluation., and I genuinely hope the next guy flying a Corvair powered plane reads them, takes them to heart, and acts accordingly.




PS, if anyone is tempted to use the comments section here to say anything about the Piet pilot, Other than “I hope he fully recovers” , please don’t. The event has happened and nothing will change that now. The story here isn’t about one man’s mishap, its about making sure that your own personal first flight goes just like Andy Mechling’s. And that outcome solely depends on decisions you will make. 


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.

2 Responses to Two very different Outcomes: Choose your own path.

  1. David says:

    Hi William, you know it cost me $3000 to follow your advise about my fuselage welding on my Bearhawk, but it is stories like this that make me glad I did, And really deep down I knew it probably was not up to aviation standards and I would be wiling to bet it was the same situation with this guy. In the other forum I follow I put my dilemma out and many builders would tell me that oh those welds look good. Well I considered the source and most were at the same level I was in my welding ability. So that is one reason why I sought out your advise. I think you saved me much more than money by giving that advise. So you keep being an opinionated bastard and telling the truth no matter how it hurts or how much it cost, because the cost can me much higher than if you did not give the advise or the cost of an idiot not taking it. Keep doing what you do man!!!

  2. Lane Seidel says:

    One proud moment of my 750 build was when you stopped at my hangar, looked at my 750, ( I thought you were a DAR) and said “It looks wonderful “ I was flattered too say the least. A good bit of how my build is going I have to give you credit. I have read every post in this blog and almost everything on Between all that and the corvair colleges I have been to I feel “schooled” on proper assembly techniques. I can’t wait till first flight tome as I know mine will perform as it should!

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