“I sure hope his opinion is worth money to someone”


John Tower was a four term US Senator from Texas.  Between his service in WWII and being a reservist, he wore the uniform of the US Navy for 46 years. He was on the Senate Armed Services Committee for 20 years; he was on the Joint Committee on Defense Production for 16 years; Although he was a Republican, he lead the ‘Tower Commission’, that investigated and condemned the Reagan administration role in the Iran Contra Affair. After leaving the Senate Tower was the Chief US negotiator of the Strategic Arms talks at a critical time in the Cold War.


In 1989 President Bush nominated Tower to be US Secretary of Defense. Because he had never been a man of blind party loyalty, Tower was attacked on many fronts in one of the ugliest Senate confirmation hearings in history. At the height of the battle in the Senate, Towers enemies stated he was unqualified to be Secretary of Defense, because after serving in the Senate, Tower had worked for General Dynamics and was paid about $200,000/yr. One of Towers supporters went to the microphone and “We are speaking of making this man United States Secretary of Defense, on these issues,  I sure hope that his opinion is worth money to someone.” 


With the goal of finding someone who had not been paid for their perspectives, Tower’s nomination was defeated by a coalition of his political rivals and enemies.  Another nominee was found, a relative unknown from a state where he had few detractors. He was easily confirmed, 92-0, and thus began the rise to power of a Wyoming Congressman named Dick Cheney.




Your Aviation Connection: In budget experimental aviation, there is a small (10%) but internet vocal minority that will constantly spout the myth any person who runs a profitable or successful business will advocate products and procedures, motivated solely by quick profit. In this distorted view, anyone who is ‘successful’ can’t be trusted, and their track record should be ignored in favor of getting advice from people who’s opinions have never been valuable enough for builders to spend money on.


This is a disease that doesn’t affect mid level builders like RV series builders. A part of the reason why their are 10,000 flying RV aircraft is the message Profitable=Evil doesn’t resonate with them. They want to build a proven aircraft, and they want to fly it. They are not interested in getting sidelined by conspiracy theories on success. To the contrary, the majority of RV builders selected Van’s Aircraft, specifically because it was successful and profitable. To sane people, this is taken as evidence of having a good and proven product.


When people who are against trusting successful people need medical attention, do they look for people who didn’t make it through med school? Do they look upon every successful professional with suspicion? Do the automatically trust the opinion of every amateur or failure? Your guess is as good as mine, I am an aircraft mechanic, I have little understanding of that kind of psychology.


On the internet last week, the claim was made I advocate pressure cowls because I make money selling baffle kits.  This is a joke, first because pressure cowls work, evidenced by 98% of RV aircraft and 100% of Cessna 172 and 150’s having them, second, we have more than a hundred of flying Corvair powered planes that use a pressure cowl, but lets not forget the point, I don’t even sell baffle kits. Even if I did, I am well known as a person who can’t be bought: Read this story: Expert Witnesses in civil Aviation trials. and know that I was offered $55,000 for 2 hours of testimony against Cessna, and I told their lawyers to “F–k Off. ”  In 2001, I had several attorneys promise me a million dollar settlement if I would sue the PIC in my accident. I told them to drop dead also.   So perhaps it seems unlikely that I would sell out for the ‘big money’ available from Corvair parts sales.


The anti-success line sold on internet groups isn’t just aimed at Corvairs; I have seen it used against any VW company that lasted, about half of the aircraft plans sellers, and a great number of people who offered parts for plans built aircraft. The people who sell this idea claim to be defending traditional homebuilding, but what they are really doing making it unattractive for people to make products of basic planes, to take away the opportunity for some builders to choose for themselves products that best serve their individual time vs money equation.  If you are a grass roots homebuilder who wonders why there are “A wealth of products for the wealthy“, but far fewer choices for those on a budget, here is a big part of your answer.


Here is irony: One of the things I do with the modest profits from our 27 year business is put them back into events that serve grass roots builders like our free Corvair Colleges: Corvair College History….in photos. and use the time to write about our R&D and testing projects: Testing and Data Collection reference page. Yet, a number of people who claim I am solely motivated by profit, have actually attended a Corvair College, and certainly almost all people who make the claim have learned something from my websites. These are the some of the people I was writing about in this story:The Hypocrisy of Homebuilders.


Every builder will choose his own path. Some will follow the proven path because their goal is success, and they interpret success as the sign of good product or service. I am glad to assist these builders, no matter how big or small their budget is.  Others, will choose to condemn any successful company, for reasons that are important to them, but in doing so will greatly diminish their personal odds of building and flying a reliable plane, all as the years drift by and their time runs out. Pick your own personal path carefully, most people don’t get two chances at this.


Above John Tower in the 1960’s. If you can see past the political necessity of his vote against the Civil rights act to gain office, the man had a long run where he put his loyalty with his conscience instead of either party. It wasn’t a long term strategy for gaining the favor or protection of his party. He was killed at age 65 in the crash of an Embraer twin turboprop, a scheduled airline flight. The accident was traced to the failure of a Hamilton Standard propeller. A later, nearly identical fatal accident caused a major safety probe that laid responsibility on Hamilton Standard’s overhaul practices.








An Internet drama in a teapot.


A little internet drama is a guilty pleasure of many aircraft builders. Submitted for your approval, a little drama that ran this week; It has a cast, a plot and a twist. Fun, but in the end it is only drama, and like a dozen other dramas before, it entertains, but doesn’t advance your plane toward flying.



Mark from Falcon Heads, Roy from Roy’s Garage, and 601XL builder/pilot Ron Lendon.



At the end of last year, I privately told Mark and Roy that I was no longer going to have them at Corvair Colleges nor in my booth at Oshkosh. After nearly 10 years of being their single most vocal supporter, I was tired of Mark not making heads and Roy telling people his work was “Technically Correct” with the implication that people choosing other suppliers were making a mistake. To retain some portion of builders, they decided Mark would come up with a special set of magic head mods for $500, and Roy would run people’s engines on his dyno with promises of further power increases. To sell this to people, they enlisted Ron Lendon to put it on his plane, and then tell people what an improvement it was. The broke the ‘story’ on the “Corvaircraft” discussion group, a venue where I am not allowed to participate.


It all sounded pretty good to people who like a good drama/conspiracy theory. Mark and Roy had “discovered” the dirty secret of Corvairs: The way we tell people to build them (Just as Mark and Roy have done for years) is terribly down on power. They claimed to have raised Ron’s power output by something like 24%. Ron followed up with a detailed flight report that showed his plane to now run 116-117 mph, a large improvement. Roy then comes in with some graphs showing Ron’s plane now makes 100 HP.


Sounds great, except:


Several well known and trusted 601XL pilots with 2700 cc Corvairs chime in to say that their planes are that fast already. Lynn Dingfelder and Phil Maxson, who have both been flying for years, point out that their planes do 115 mph, and Ken Pavlou’s will break 120, in the same configuration as Ron Lendon’s in spite of Ron’s engine being a 2,850 cc. The logical observation is that these unmodified airplanes have the same output as Ron’s now does, which Roy’s dyno said to make 100HP. Most people concluded that the test validated my long standing power output claims, because there is little variation in 601XL airframes, so the same speed  = the same power.




Points to understand:


Roy claimed to have previously tested a 2700 cc engine and the output was only 82-83HP. His contention was that all 2700s built to my suggestions had that power output. Clearly that wasn’t so, based on the other pilots reports compared to Ron’s ‘modified’ 2850.

I have little doubt that Ron’s plane had an improvement. He had been plagued by engine problems in his first years of operation, mostly caused by his adamant use of a obscure carb of a 65HP engine. In spite of working for GM for decades and having significant flying time, Ron  missed that his engine was running lean enough to damage itself bad enough to need a rebuild. His plane was never a particularly good performer by 601 standards. He got another Carb, much closer to correct, but still didn’t recognize it was running lean.


There was no ‘before’ run made on Ron’s engine, just an after. Although he mentioned that his plane now has flat top pistons, he didn’t mention that the heads were changes from 95 to 110 high compression ones,  the valve size increased, and again the carb was made richer. because it was never tested, there is no before and after, but judging from performance, his plane does run much better, but evidently not significantly better than other 2700cc 601XL’s. Changing the compression from 8;1 to 9.5:1 and making the carb a lot richer could account for the improvement alone. Perhaps the other ‘modifications’ have negligible or negative effect.

A great claim was made that Roy’s dyno was scientific because it used a data program called “Labview”. A guy who got it from his work traded it to Roy for a discount. Same guy claimed “This is basically the same software & hardware that is used on a $50-$100K dyno.” I tend to disagree because you can go on National Instruments website and see they sell the Labview dyno soft ware brand new for $1,290. I don’t think having  that software makes Roy’s dyno the equal tool as a $100,000 dyno.


No mention was made of correcting the dyno runs to standard atmosphere. Without this, there is no comparisons between engines, even ones run a few hours apart, far less weeks or months apart.






Above, Roy and I running an engine I built in 2014 on his dyno. Several people chimed in on Corvaircraft to praise Roy for his testing, even though they have no experience with dynos. Does this look like a $100,000 piece of equipment? On the day in the photo we could not get a test more than a few seconds long, and Roy had to manually manipulate the controls, there was no real data from this. I am sure it is better now, but this isn’t the “technically Correct” infallible tool that some people suspect.  If you would like to read a dozen stories of practical testing spanning 10 years, look here: Testing and Data Collection reference page



Above, a 2008 dyno calibration run in my yard in Florida. Notice Kevin and I are wearing jackets. We’re waiting just before sunset for a rare weather phenomena to occur: a perfect standard day of 59F 50% relative humidity and a pressure of 29.92. Any time you read a dyno report and it says “corrected horsepower,” they’re making a calculation, sometimes accurate and sometimes not, to adjust for their test conditions not being at standard atmosphere. Because we live in Florida near sea level, there have actually been three occasions the past years when these conditions were met during daylight hours on testing days.

Our dyno relied on the super accurate optical Prop Tach for the rpm measurement and it will only reliably pick this up in daylight. A few minutes after the photo above was taken, we made a dyno run which required no correction. By testing the same engine later in the week, we reconfirmed our correction factors for this particular dynomometer and we retained accurate measurements all year round. If you want to read the whole story, it is here: Dyno testing Corvairs, 2008 Any dyno run that doesn’t reference a correction to the ‘ICAO Standard Atmosphere’ has no meaning, and there is a significant difference between  the reliability of a calculated correction and a measured one, as we are doing above. People get excited hearing about ‘software packages’ but in reality the value of the tests relies on basic things like atmospheric corrections. 



Above, Ron Lendon, running his engine on my stand at Corvair College #17, having a good moment. Yesterday he said this on Corvaircraft: ” I even heard WW say to Dan W. that he would fly the engine I just built at CC17 to the Bahamas. But I don’t here him saying that now, no he is heaping his opinion on people he called friends because they are behaving as he did several years ago. “  A big part of why Ron’s engine ran great on my stand is that my stand has the recommended carb, a MA-3SPA. He promptly went home and bolted the incorrect carb on his plane, because it was cheap, starting a long series of issues. Oddly, the people Ron is championing today, Ron and Mark, supplied him with parts and service that he was previously angry about. As for his evaluation of the behavior of ‘friends’, perhaps he can review the definition of “ingrate.”



As for Mark or Roy being able to claim ignorance of the output of engines they happily built and sold to people, I submit the photo above: Marks EFI 2,700cc Corvair in 2007, on my dyno, right in front of mark’s shop in WI. He certainly didn’t think this motor, nor a carbureted one was 82hp that day. You can also see that Mark was present in the calibration story above. Roy had also flown as a passenger in Lynn Dingfelder’s 601XL and saw what a good running plane, with a stock 2700cc ww engine could do. Before making his claims this week he understood that his ‘modified’ engine in Ron’s plane was no more powerful than Lynns.

 My testing was absolutely satisfactory for Mark and Roy to sell heads and engines to people for years, but somehow they have suddenly ‘discovered’ that none of these engines worked, coinciding with them becoming unwelcome at events I am hosting. Think it over.




That concludes todays entertainment programing. I am headed back out to the shop to prep for the next Corvair College, I suggest builders intrested in progress do the same.


Great moments in aircraft testing -2003-2004-2008


In two weeks we will be headed back to Oshkosh. Once there we will be surrounded by hundreds of companies that will all attest on a stack of Bibles that they have carefully tested all of their products to protect the safety of their customers. In with these people will be at least 30 companies selling engines. Every single one of these companies will tell you without blinking an eye that their engine power output numbers are the result of careful Dynomometer testing. Almost all (90%) of these companies are lying about this.


Traditional dyno testing is expensive, and a bit of a production to adapt an aircraft engine to. To learn much, it requires hours of evaluation, and runs at different conditions. Any company that does this would be justified in taking a photo of this milestone in their company history…….except you can politely ask to see a photo of their engine on a dyno, and of course they will not be able to produce a single image of their engine running on a dyno. I actually had one company tell they had done 100 hours of testing, but had forgotten to take a single photo of it. In an era where nearly every human has a cell phone that is also a camera, please tell me who would believe this?


There are many kinds of dynos. Basically they all apply a load to the engine, and then measure the equal and opposite torque reaction resisting this load. No Dyno measures HP; they measure torque. HP is a calculation based on torque and RPM. If you building a plane, you don’t need to know this, but ideally everyone selling engines would, (but they don’t). A real motor head, like yours truly, knows this stuff. Combine this with some basic fabrication, and “Taa Daa!” the $500 dyno. Our dyno used the prop to generate the load,  allowed the engine to rotate on it’s crank axis by using a front spindle from a Corvair car, and measure the torque with a hydraulic cylinder. Later we simplified it further with an electronic scale for measurement. Using a digital optical tach, the accuracy measuring HP was within 2%


I didn’t invent this kind of dyno, it has been around a long time, pictures of them in 1960s Sport Aviation magazines. This isn’t even the simplest kind of dyno. In one old Sport Aviation there is a picture of a Corvair  hanging on a steel cable turning a prop, with a wooden arm touching a scale. Yes that works also. The pictures of our set up have been on our webpage for more than 10 years. It would be very easy for any company selling engines at Oshkosh to have built their own version. Easy, but not as easy as telling people they have hundred of hours of testing, but forgot to take any photos.


2003- Above, Oil system testing at Spruce Creek airport, 2003. We were testing how much pressure loss the cooler had when the oil in it was cold soaked for an hour at 32F. Testing like this is serious business. Note that Gus Warren liked Becks Dark, and I liked Michelob. Lot’s of companies like to have the appearance that they test products: they put people in lab coats and have them make scientific faces.  I don’t care for appearances, I just want results, and the picture shows we drank beer while we let the oil cool off. I can put on a lab coat a lot faster than a salesman can become a motor head and teach builders anything valuable.


2004- Above, an O-200 on our dynamomemter; test crew from left to right, above: Gus Warren, Detroit Institute of Aeronautics, A&P 1990; Steve Upson, Northrop University, A&P 1976; yours truly, William Wynne, Embry-Riddle Aeronautical University, A&P 1991. While the way we dress may be slow to catch on in high fashion circles, we certainly know our stuff about all types of aircraft powerplants.


2008- Above, Kevin and I are standing on my front yard, wearing jackets. We were waiting just before sunset for a rare weather phenomena to occur: a perfect standard day of 59F 50% relative humidity and a pressure of 29.92. Any time you read a dyno report and it says “corrected horsepower,” they’re making a calculation, sometimes accurate and sometimes not, to adjust for their test conditions not being at standard atmosphere. Because we live in Florida near sea level, there was actually  three occasions in four years when these conditions were met on testing days, and all our results we calibrated against these standards.



How you can build a Dyno for $500 if you know how they work and you can weld:

Dynamometer testing the Corvair and O-200

A page devoted to all kinds of testing:

Testing and Data Collection reference page




Comments on aircraft accidents


I am well known in experimental aviation for speaking of the things we can learn from accidents. I have an entire section of my website devoted to this: Risk Management reference page . Very few people in our field do this. The reluctance of most companies to comment has nothing to do with protecting their work nor our industry, it is simply the unspoken acknowledgement that very few people are listening, and altering their actions as a result of findings. I have worked in experimental aviation for more than a quarter of a century, I was trained as an accident investigator at Embry-Riddle, and the focus of my work is teaching builders, and yet I have to concede that my fellow aviation business owners are actually correct, very few people in experimental aviation are willing to alter or improve their behavior over time. They may want to read about accidents and comment on them, but the statistics say that few people are learning and changing their actions.


If you are an individual, it doesn’t matter that 90% of people are doing what 90% have always done. This statistic is a concern of the industry, but it need have no effect on you. It applies to people who behave like a herd, but not the individual. I write the following points with the assumption that I am speaking with an individual, but the acknowledgement that this will also be seen ( I don’t use the word read here) by people of the herd who will ignore, take offence at, or misquote it. I can do nothing about that because my craft is teaching aircraft mechanics, and if my goal was to control herds, I would have been a shepherd.


For individuals who want to learn something, the following points are based on 26 years of continuous work with Experimentals:


Know the ” WW 100 Rule “: If the prototype breaks or has an accident before anything is being sold, that is called testing and R&D, and that is what responsible companies do; If 3 or the 5 first prototypes have accidents before getting to 100 hours, there is likely an issue with the product; If 2 of the first 10 have accidents before getting to 100 hours, you are likely looking at something about people, not the product; if 20 of the first 100 people have an issue before getting to 100 hours, then you are certainly looking at a human issue because it logged 8,000 hours for people who used it properly, and I have plenty of evidence that more than 20% of people have no judgment around planes. Read : A visit to the insane asylum .


There will always be accidents with every plane and product, even ones with several hundred examples. Fools would have you believe this a reflection of aircraft companies randomly producing a defective mechanical devices, and that is a joke. What it actually shows is that there is a large persistent group of people who think that transition training, following instructions, biennial pilot reviews, pre-flighting and spending money where it is needed, do not apply to them. This is not unique to flying, think of anything you engage in, boating, shooting, motorcycling, eating, breathing, whatever, there are at least 20% of people who also do these activities with a willful disregard for safety. The only difference with flying is that the results make better TV news.


The fleet of flying Corvair powered planes is about 400-500 active planes. While my original builders may be as low as 5% fools, there are strong industry records that show second owners of aircraft are a very accident prone herd. They are drawn from modern societies’ Darwin award candidates, and they are often people who thought learning enough to build a plane was for egg heads who like books. Second owners have a very high percentage of people with the pre-flight motto “kick the tires, light the fires.” These factors produce a steady flow of accidents. In most cases, if the engine is a Corvair, I will get a call from the FAA or the NTSB within 24 hours of the accident.


Remember Martha Stewart?; most people think that she went to jail for insider trading. She did not, she actually went to jail for simply misleading (not even directly lying to) Federal agents conducting an investigation. When a billionaire can’t hire enough lawyers to keep them out of jail after misleading Federal investigators, a reasonably intelligent blue collar guy like an aircraft mechanic concludes one should only say pure factual information to Federal agents. Not only because it is legally a good idea, but it is also the ethical thing to do.


There are rules about what you can share before the preliminary report is filed. Now, just think about how many times I have been informed about what was found, but then read stupid speculation from people on the internet, saying things I already knew not to be a factor in the accident. In the last 25 years, I am yet to see a single speculator, who was later shown to be absolutely wrong, come back on the net and admit that their speculation was complete BS.


Random Comments on the Net: Following an accident, there will be people who always comment, and in most cases, they will not use their real name. This may be the guys friends “sticking up for him”, but you are almost certainly looking at one of three things; 1) An on line know-it-all.  2) An axe grinder trying to do some PR damage by speculation. 3) A small business competitor. (The most famous cases of this were on the Matronics/Zenith list where there were it was later shown that many of comments following accidents originated from other aircraft companies.) Anything that doesn’t come with a guys name and address, from a known person is to be considered BS.


When there is an accident, new builders focus on it, but the time spent learning about accidents, particularly when people are just speculating, would be far better spent studying the people who didn’t have an accident. I have seen countless new guys focus on what they ‘think’ happed in some particular accident, but they can’t name a single successful builder’s plane they have studied in the same detail. This is stupid. Their time would be much better invested in learning to emulate the success of another builder who isn’t having accidents. Good flying is about patterning your success after what is proven to work. Even if a builder had a god’s eye view of what went wrong in every accident of the type of plane he is building, this still doesn’t tell him anything about what is right, only what is wrong. Study success at least as much as failure.


Keep in mind that when you see an accident, you are arguably looking at the guy who wasn’t following procedures nor exercising good judgment. If he comes right back and says, “I f^#*ked up, let me tell you the mistake I made”, he is the total rarity that can teach you something. but far more often, the person who had an accident says nothing because they didn’t know what they were doing, or still argue that they were doing nothing wrong. A person in that position has nothing to teach you.


After an accident, out comes the guy who met him: In many cases this speculator is the guy who knew the guy from his EAA chapter, or knew him from an airshow. Invariably the guy will include a comment like “I thought his plane was nose heavy” OK, and this is based on? Notice the guy never says “I did a weight and balance on it personally and found it to be at the front of the CG range in the drawings” it is always some random judgment, often meant to express how his own personal plane is somehow better than the one in the accident. All of these guys “just want to share facts” but in realty they don’t know what they are talking about. Even well meaning guys who post a link and say “He had an engine failure” are jumping to a conclusion themselves.


Do you know that the FAA lists running out of gas as a loss of power? I worked for several years with the late Jeremy Monnett trying to get a category called “Gross Pilot Error” to be included in the descriptive terms because we both thought that is a better description of running out of gas than calling it a “loss of power.”


I have written countless times that any commentary on an accident, other than a PIC report or the actual accident investigation is nothing but speculation, But this never stops idiots from doing it. Consider that both this plane: Flying Zenith 750 w/3000cc Corvair, Doug Stevenson, California and this plane: New Zenith 601 XL(B), Conventional Gear, Jerry Baak, S.C. were destroyed in accidents.  If you search the stories on websites, you will find at least 200 random speculations about what caused these accidents, mostly centered on what a terrible engine choice the Corvair is. Ready for reality? Both aircraft were run out of gas.   I flew to California and proved this on video:


  The Federal investigator agreed with the conclusion. Yet not one single speculator had the self-respect to go back on any list and say “I was wrong”. You can wait as long as you like and you will not see that on the internet.


For people thinking of speculation on vague info, consider how stupid the TV news commentator feels today about reading the “Confirmed Names” of the pilots in the Asiana 214 crash:






Above, a 2007 picture of the homebuilt of Ken Lien of WA state. The following year, he was killed on the very first flight. You can read the story I wrote a long time later here: Risk Management, Judgement Error, money in the wrong place. By an absolute coincidence, a life long best friend of Ken’s, named Denny Jackson became my neighbor at our airport in FL just after the accident. Denny was deeply hurt by his friend’s death, and finding out that I was the ‘Corvair guy’ lead to him angrily confronting me at our EAA chapter. He was 6’5″ and 325 pounds and not to be trifled with. Because I was part of the investigation, I already knew what Denny did not: It was caused by his friend putting his carb together incorrectly, it had nothing to do with Corvair engines, yet I could not say this to him, I could only ask that he withhold judgment. Months later, Denny understood the report, came and explained that he was just hurt at the loss of his friend. I told him I might have done the same thing. We ended up as friends, spent a chunk of time around the airport together. Denny’s picture is now on our EAA chapter wall, as he was taken by cancer 3 years ago.


Reference posts and updates to FlyCorvair.com


Below are some notes on reference pages:


A good memory: Standing with my father at Sun n Fun 2006, in front of a piece of hardware from his era of Naval Aviation, an F8F Bearcat. Although Dad’s hat says CVN-65, he joined the USN in an earlier era,  3 July 1943. 


Click on any color link below to read the story:


Grace and I have been collecting stories and grouping them together on the “reference pages.” We are doing this to have the stories that were written individually now grouped together by subject. The location of these reference pages is right on the front of the main page of our traditional website : http://flycorvair.com/


If you have not looked at in in a while, about 70% of the subject entries have had their content changed in the last 30 days. Almost all of the headings on the main page are now reference pages. For example, both the Engine Operations reference page and Corvair College reference page that we just put up here yesterday, will also be conveniently accessible on the main page of our other site.


But notice also the Testing and Data Collection reference page I wrote a month ago has been updated and installed on the main page of the other site also.


I would like to draw attention to the Risk Management reference page, I wrote it a week ago, but last night I took some time to update it with some short biographies and pictures of friends. While you are there notice that last nights story Concerned about your potential? was specifically written as an introduction to the risk management page and it has already been installed there.


This last point shows that I can update the reference pages easily, the way I put the story DonPietenpol Passes, 1/8/14 into our existing Corvair – Pietenpol Reference page. I am going to keep updating rhe new stories into the reference pages like this to keep them up to date. Our traditional site will be a lot less dated this way.


A very important act that our friends can do for us is to post the appropriate link on discussion groups when the topic comes up. If you belong to any of the airframe discussion groups, you are aware of how often a new guy will ask a legitimate question on where to get started or ask for more reading on his choice of airframe. I ask that friends post a short direct link to the appropriate reference page. Mind you, the discussion does not have to be focused on Corvairs. There are many stories and useful information for Pietenpol builders using various engines on our page, and last week about 60 of the page reads on the risk management page came from a like that a friend shared on a forum devoted to gyroplanes.


Besides the fact that I think there are direct safety benefits to builders reading the comments, I think it does demonstrate to other members of the experimental aircraft building world that the Corvair movement is made up of traditional home builders who are thinking people. There are benefits to the efforts of all Corvair builders being better appreciated. It attracts a better cross section of builders for next year, and it also tends to discourage the imbeciles who worship stupidity from spending time in our camp, doing some damage and departing. If I gently roll up the welcome mat on the latter group by mocking people who trust ‘luck’ over preparation, and using two syllable words, all of our lives will be a little more sane in the next years to come. -ww

200 Stories of aircraft building


Below are 200 stories on aircraft building that I wrote in the last 2.5 years. This is just the top 40% most popular ones from our blog. They are loosely grouped, but you can scan through the titles, and you can read the full story by clicking on any colored title.

There are some real classics like “Unicorns vs Ponies”, but most stories are directly about flying planes and running engines. You don’t have to read it in one sitting (it is about 250,000 words, half the length of “War and Peace“) But keep it handy for a reference page. -ww.



Basic Corvair information

Shop perspective: Mastery or ?

Concerned about your potential?

A visit to the insane asylum

Glider flying – a funny story

The Cherry Grove Trophy

Model T of the air?

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

More Thoughts On Economical Aircraft

Testing and Data Collection reference page

Why Not the Panther engine?

What is a core engine worth?

Corvair College reference page

Corvair College History….in photos

College Tech

Basic Corvair College Skills, examples of learning

Zenvair’ Information board formed

Calling All “Zenvair” Flyers……601 / 650 / 750

New Numbering System, Final, please print.

College engine build options for closing the case

Getting Started in 2013, part #1, Crankshaft process options.

Getting Started in 2013, Part #2, Group numbering system

Getting Started in 2013, Part #3, The Camshaft Group (1100)

Getting Started in 2013, Part #4, Case Group (1200)

Getting Started in 2013, Part #5, ‘Allan Able’ short block.

Getting Started in 2013, Part #6, ‘Bob Baker’ short block

Getting Started in 2013, Part #7, ‘Chas. Charlie’ Short Block

Getting Started in 2013, Part #8, ‘Davie Dog’ Short Block

Getting Started in 2013, Part #9, ‘Eddie Easy’ short block.

Getting Started in 2013, Part #10, Piston and Cylinder options.

Getting started in 2013, Part #11, Comment of the day

Getting Started in 2013, Part #12, Piston Choices

Getting Started in 2013, Part #13, Basic piston/rod/cylinder combo.

Getting Started in 2013, Part #14, 2,850 cc piston/rod/cyl. Kits

Getting Started in 2013, Part #15, 2,775cc, (imaginary piston)

Getting Started in 2013, Part #16, 3,000 cc Piston/cylinder kits

Getting Started in 2013, Part #17, Short block cost chart.

Getting Started in 2013, Part #18, A look ahead

Getting Started in 2013, Part #19, Cylinder Heads

Guest Writer: Pietenpol builder/flyer Kevin Purtee

Guest Editorial, Arnold Holmes On Affordable Aircraft…



Planes flying on Corvair Power

Corvair planes and projects on You Tube

Corvair Powered Davis DA-2, w/EFI

List of Corvair Powered Zeniths

Zenith 750 / Corvair reference page, October 2013

Zenith 601/650 – Corvair reference page November 2013

Corvair power for Panther and Sonex reference page

Pietenpol review in pictures, 15 more Corvair powered Piets

16 Flying Corvair powered Zenith 601/ 650s

Corvair – Pietenpol Reference page

Gary Burdett, 2,850cc Zenith 750, now flying. (engine selection)

New 3,000 cc Cleanex, Dale Williams, SC

Panther Roll out.

Zenith 701- Corvair reference page, November 2013

New Photos of JAG-2, a Corvair powered twin.

JAG-2, Corvair Powered Twin, Jim Tomaszewski, N.Y.

Zenith 601XL-3100cc Dr. Andy Elliott

Zenith 601XL-2,850cc, Woody Harris

Zenith 650-2700cc Dave Gardea

2,700cc-Skycoupe-2002 Photos

New “Zenvair-750″, Jeff Cochran, 2,850cc engine, N750ZV

Flying Zenith 750 w/3000cc Corvair, Doug Stevenson, California

Corvair powered Dragonfly, Charlie Johnson, aka ‘One Sky Dog’

Zenith 750 Flying on Corvair Power, Gary Burdett, Illinois

KR-2S at 700 Hours – Joe Horton

New Zenith 601 XL(B), Conventional Gear, Jerry Baak, S.C.

New Pietenpol, 2700 Corvair, Don Harper SC

New Pietenpol, Gary Boothe, Cool, Calif.

Two More Flying Planes: Merlin and VP-2

Corvair Powered Merlin Flying Over Newfoundland

Floats on Snow, Corvair powered Merlin

Flying 2,850cc Cleanex, Clarence Dunkerley

New Pietenpol, EAA #1279, French Valley CA

New Pietenpol #3, Mike Groah, Tulare, California

Guest writer: Phil Maxson, flying a 3100cc Corvair in his 601XL

Another new “Zenvair” 601XLB, Jim Ballew, 2700cc

Flying Zenith 750, Tom Siminski, 2700cc, PA.

Flying 2700 cc Zenith 601 XL(B), Alan Uhr



Complete Engines for Sale

2012 Corvair Engines For Sale: 100, 110 and 120 HP

World’s Strongest 3,000cc Corvair, built by Greg Crouchley

Panther Prototype Engine 3,000 cc/120 hp to OSH

3,000 vs 3,100 cc Corvair engines

3,000cc/Billet Crank Shortblock, Destination: Waiex

High Volume Oil Pump

3,000cc Engine Running

3,000cc Case Modifications.

Billet Cranks Made In The USA

Chinese Crankshafts

Chinese Crankshafts for Corvairs, update 2/17/13.

Notes on Corvair flight engine oils.

Shipman Engine at CC#22

A Tale of Two Spark Plugs……

The Panther’s engine, worlds strongest Corvair flight engine.

Panther Engine Is Alive … ALIVE

Engine Operations reference page

The case of the Murphy Rebel, “eyeball vs. testing”

Corvair vs O-200…. weight comparison

Testing Head Studs

Balancer Installation

Gold Oil Filter Housing, Standard and Reverse

Front and Rear alternators, their part in numbering system

Thoughts on cold weather operation, minimum oil temps, etc.

Cooling with J-3 style cowls. (Pietenpols, Cubs, Biplanes, etc)

Spark Plug Installation

Starting procedures on Corvairs, 2,000 words of experience.



Stromberg Carbs

Carb applications, choices people make

Fuel Injected Corvairs

Carburetor Reference page

A question of Carb location…..

Mechanical Fuel Injection Testing

Stainless Steel Exhaust Systems

Fuel Injection – Corvair flight engines reference page

New die spring landing gear on a Pietenpol, 10 a.m.-4 p.m.

Pietenpol Products, Motor mounts, Gear and Instalation Components.

MA3-spa carb pictures, Wagabond notes.

In Search Of … The Economical Carburetor

Pietenpol Box Spar Construction, 6/27/13

Pietenpol Mount on airframe

Panther Engine propeller test

Kitfox Model IV with Corvair mount

Corvair Motor Mount for Bearhawk LSA

Inexpensive Panel……..part one.

Inexpensive panel…….part two.

“William, you ignorant troglodyte”…….(instrument options)

My favorite Tach; Stewart Warner 82636.

Ammeters Pro and Con, & Flying like there is no tomorrow.

Corvair Oil System, information on oil pressure gauges.

MGL vs Corvair ignition issue

Measuring Cylinder Head Temps on Corvairs.

Corvair Cooling

Corvair Cooling, Three 2007 examples from our hangar.

Cylinder Head Temperature measurement

Cowling Inlet Area, marketing, accident stats, Darwin where are you?

Corvair Cooling, something of a human issue…..

CHT part #5, flight data from Zenith 750

Engine Cooling Factory Sheet Metal

Pietenpol Fuel lines and Cabanes

Three Pietenpol Motor Mounts

Zenith 601/650 Motor mounts, P/N 4201(A)

Intakes and Internet myths



Welcome to The FlyCorvair.net Blog

Back from the road, notes on Communications



Unicorns vs Ponies.

Sunday, a long day at the airport.

Fixing America is going to cost each of us $1.69

Greatest Book on Flying Ever Written, (Is your life worth $16?)

A thought on Easter….

In defense of plain speaking……

Turtles and Cell Phones, 6/24/13.

2,500 words about levels of aircraft finsh……

Steel tube fuselages, “Safe” planes and 250mph accidents

Cessna’s Chinese adventure a failure.

Communist Chinese government at Oshkosh

Risk Management, Experience vs Judgement.

Risk Management, Wrong airframe, Wrong experience level.

Effective Risk Management – 2,903 words

Risk Management, Factor #1, Judgement.

“If only someone had told him……”

Expert Witnesses in civil Aviation trials.

Great tales from discussion groups…….part #1

Vern’s Aero-Cars

Fun with Agkistrodon Piscivorus and Vern’s Aero-Trike

Cloudn’t have happened to a nicer guy……

Built by William Wynne? Built according to The Manual?

Risk Management, Judgement Error, money in the wrong place.

Flathead Ford, 71 cid. Freedom to pursue happiness.


History and aviators:

B.H. Pietenpol, Patron Saint of Homebuilding

Robert Hedrix, Aviator, Nha Trang, 1975

The Quote, 1927, C.A.L.

James Stockdale – Philosophy

Sterling Hayden – Philosophy

A Father’s Day Story – Lance Sijan

Three Aviation Stories

Charles Poland Jr., An American of whom you could be proud.

Carl Sagan, Corvair Owner, Practical Philosopher, Individual.

William Edward Wynne Sr. – Father’s Day Notes



Corvair College #22, March 9-11, 2012 in Austin, Texas

Panther Prototype Engine 3,000 cc/120 hp to OSH

John Moyle, noted aviation enthusiast, passes -1/16/13

Corvair College #25, In Photos

Corvair College #23 – 2850cc Engine, Roger Grable, CH-750 Builder

House Call on Pat Green’s 1,000 Hour Pietenpol

Brodhead, Oshkosh and Beyond 2013

Wisconsin 2012 Air Adventure

Zenith 750 Builder Blaine Schwartz

Corvair College #23, 2700cc Engine, Spencer Gould, SP-500

Sun N Fun 2012

Randy Bush’s Pietenpol hits 500 hours.

Corvair College #27 run on film

Franklin Engine Runs at CC ##22 KGTU Spring Break 2012



Thought for the day: “Censorship” on the net

“If your reading this, and you have never met me, let me teach you one single important thing right now that most people don’t yet know: Censorship is the rank amateur way of controlling people. It is not effective at all, especially in the information age. However, it has three highly effective off spring that are the tools of the professionals. These are Disinformation, Self doubt and Fear. These three are far more effective, and they work even when you are later exposed to the truth. If you look at it, negative people out there do all three.  They claim to know of failures, but have no names nor dates; They cite nameless “experts” who disagree with what has been shown to work; they make new builders doubt all the positive and factual reports, and gradually over years, they get you to be afraid to trust things that have been well proven to work. These efforts would have had little effect on our grandparents, but several decades of intense consumer marketing along the same lines makes all of us more prone to distrust, more likely to see some truth in the plausible lie. Unwittingly, many of the people who cry censorship are actually employing  the tools of the real propaganda artist.”




For a number of years I harbored the delusion that I could participate in on-line aircraft discussion groups, and write some things that would allow new builders to understand that we had pioneered  very effective and reliable ways to build an operate Corvair flight engines. I freely admit that I was wrong. On any discussion group where people who are known only was “Flyboy26” or “RVguyCN” have the exact same size soap box as people with real names, specific experience, links to photos, there is no chance for new people to sort useful reality from dangerous fiction.


On discussion groups I tried to advocate that people should use real names and they should never ‘recommend’ anything that they had not personally and specifically flown behind. I also advocated that all references to third party experts, require also stating that persons name, so people couldn’t say things like “A local expert here who has built 25 planes says that will not work.” These sounded like very reasonable ideas to me if we were going to talk about Corvair engines in planes for the purpose of getting people flying. I was wrong about that, and a number of very vocal people always claimed that I was “Censoring” them buy not supporting their ‘right’ to say anything.


As you might imagine, I was quite a thorn in the side of people like ‘flyboy26’. I merely showed how things they advocated had long been proven by our testing not to work. Over time, these people hated me. They switched tactics to making wild claims about our products failing, they claimed to be in touch with ‘experts’ who assured them that a wave of failures was eminent, and they constantly tried to make people afraid to follow things we had long proven to work.


These tactics didn’t win builders to their ideas, but they were very effective in getting a large number of new builders to do nothing. Probably without knowing it, ‘flyboy26’ and his buddies were employing real propaganda tools, Disinformation, Self doubt and Fear. Before getting kicked off discussion groups for life, I wrote the quote above in hopes that new builders would understand.  I look back today and see that hope as delusional also.





Left to right, Three Corvair powered Zenith 601XL’s. Ken Pavlou, Roger Pritchard and Louis Leung’s planes in a row. Ken’s plane had just concluded phase one, 40 hours without the slightest issue, or need for adjustment. Roger and Louis have already flown their planes to Oshkosh. The builders of these planes are all members of a private discussion group that I formed as an alternative to open internet groups that allow comments from ilk such as ‘flyboy26’. You can read about the group at these two links:


‘Zenvair’ Information board formed


‘Zenvair’ information board, part #2


Ken had never built a plane nor engine before. The reason why his flight testing was without event, is because he followed our proven path, and took no advice from internet ‘experts’. The same week that Ken flew off his last hour, another 601 with a Corvair in it took it’s first flight.  That builder chose to listen to many people, but follow very little that I had to say.


His first flight lasted just 6 minutes, one trip around the pattern. Many of the things this man tried, like cooling plenums on the engine and a carb off an old British car, were championed by people on open discussion groups, the same people who called me a Censor for pointing out they had never tried what they advocated. When the builder got on the ground 6 minutes later, 1/10 of an hour, 1/400th of his testing done, perhaps he had greater respect for my efforts to ‘censor’ the speech of dangerous fools.