Mail Sack, 11-18-12, Steel tubing, exhausts, advice….


On the subject of Steel tubing and risk management;

601XL Builder and Flyer Ron Lendon writes:

“WW, I really enjoyed this article and was in the drag racing game in the 1970′s as a mechanic. Some of those experiences have prepared me to expect the unexpected and like the Boy Scout motto “Be Prepared”. The learning experiences of building and flying the Corvair powered CH601 have been one of the most enjoyable and exciting endeavors I have undertaken to date. Now that I’m getting older and wiser, I will be paying much more attention to the details of the proven path. Thanks for persisting my friend.”

Pietenpol builder, CC#24 grad, ATP/USMC, Terry Hand writes:

“William, You are correct that safety is not a “one trick pony”. Safety is a combination of choices, not just a single choice of steel tube over wood, for example. Safety is also a recognition of the human factor. The pilot who practices his/her emergency procedures, particularly his or her engine failure procedures, knows and flies the glide ratio of the airplane and keeps their skills up is far better, in my eye, than the pilot who kicks the tire, lights the fire, takes off, and then thinks nothing will happen when they fly 10 hours per year. But, as you have said many times, it is not safety. It is risk management.”

DC-3 owner, International aviator of adventure Tom Graziano writes:

“William, Spot on about the crash worthiness of steel tube fuselages. I’ve been around more than a few crashes. Steel tube holds up/protects the best IMHO. One AT802 crash in particular pretty much had only the cockpit remaining intact – the CSAR guys couldn’t believe the pilot survived, let alone got out and staggered down to a river to wait for rescue. (Pilot did sustain a fairly serious concussion from the ordeal.) My latest project is definitely steel tube. There are some good threads about crash worthiness over on

“I will be changing my fuel tanks from a straight aluminum tank to a polypropylene tank inside an aluminum outer tank/box. Adds a little weight, but its a price I’m willing to pay for the extra margin. Self-sealing bladders are probably the best way to go, but their weight, maintenance, life limit, cost, and availability makes them not so feasible to me. I’ve decided to install self-sealing breakaway fittings at the tanks and one or two other key places. I saw a Super Cub crash once where the fuel lines pulled away from the tanks and drenched the occupants with fuel which self-sealing breakaway fittings would definitely have prevented. Fortunately, there was no post crash fire. I believe homebuilders give too little thought or serious consideration to flammability and fire. Toxic fumes from foam, upholstery and other things can kill just as fast as fire….”

Builder Tom Griesemer Sr. Writes:

“The 1960s were — individuals worth admiring.
This paragraph is so true…-Tom G”

Tom, I can think of no better example of the poisonous effects of celebrity culture and how degrading ‘entertainment mentailty’ is than Bruce Jenner. Once a genuine American Champion in the 1970s, today portrayed as a buffoon for the benefit of ratings and consumerism. I know a number of people who work in the national media. The only bias they share is an obsession to find a flaw in any effort, the gap in a personality, the small error in any advancement. This quest to degrade or critique betrays their very ugly view of human nature, a grotesque view that does not acknowledge, and can not permit, the recognition of a Champion or a Hero. They will never focus on how Jenner trained 8 hours a day for 6 years, living near poverty, to defeat the Soviet state trained athletes in the 1976 decathlon. Yet they gleefully show you his fall where he is brought to the pettiness of dealing with a vapid family without a single redeeming quality. They do not believe that an individual, even through intense effort, should be allowed admiration of  society.-ww

Builder, CC#5 grad. and linguist Dan Branstrom writes:

“Both my parents spoke Swedish first. My dad, because he was born in Sweden, and my mom, because she lived in a farming community composed of Swedish Immigrants.For her, it was easy, because her mother had been a school teacher. My dad learned English after he immigrated to the U. S. at 17. He put himself through an academy (high School), two years of college, then seminary, and left for China at 26 and learned to speak Chinese. I asked him what the hardest language for him to learn, and he answered, “English.”

I wrote all that because I understand how difficult it can be, particularly with all the homonyms we have and our hodgepodge of spelling rules we have because our language comes from so many disparate sources William, you do things with a flair, but you flare a tubing or an airplane.Knowing you, you probably flare an airplane with a flair.To get even more ridiculous, a very dramatic person at the scene of an accident would light a flare with a flair. Thanks for the essay on construction modes. The only thing I’d add would be that a good system of restraint is mandatory. At least a 4 point seat belt should be used.-Dan”

I include this note from Dan to show that he functions as my editor when Grace is out-of-town. The corrections often come in stylish sentences like above. Dan lives in CA and has been part of the Corvair movement for a long time and has a very interesting family history.-ww


On the subject of Zenith Exhausts and Advice, Zenith 750, 3,000 cc Builder and Flyer Doug Stevenson (First person to fly a 750 on Corvair power) writes:

“William, I certainly agree with you….these discussion groups can lead you far astray. Much better to go straight to the “horses mouth.” Regarding this topic, my pipes fit perfectly 1/2″ below my 750 firewall, but I do not have any exhaust gaskets between my exhaust pipes and the pipes coming out of the heads. Should I have used gaskets? My engine seems to run and sound fine without any gaskets, and I cannot detect any signs of leakage. (Doug, I would put gaskets in, it’s a good idea-ww)

On another subject, some time back, I complained to you that my coil splitter was defective and would not allow the engine to run properly. I finally discovered the solution to the problem, but not until spending many hours searching for a solution and having four very experienced mechanics try in vain for several hours to fix the problem. I even sent the new splitter back to the factory for replacement without solving the problem. What was so confusing was that when bypassing the splitter and wiring directly from either coil to the distributor, the engine ran perfectly. I even flew the plane on one coil without the splitter for a short period until I discovered what was wrong. The answer was that the coils were wired with reverse polarity. I had learned many years ago from my hot-rodding days in the 1950′s that it didn’t matter whether the coil was wired from the power source to the + or – side of the coil, the engine ran the same. However, not so with a coil splitter, because the diodes in the splitter won’t allow the current to flow in the opposite direction. I’m bringing this to you now in hopes this information disseminated by you will save some other poor builder the problems I endured. Thanks, Doug Stevenson ps: My engine runs like a dream. I’m really happy with it.”

Doug, Thanks for the note. KR builder/flyer Dan Heath reversed the polarity on his coils before flying last year, and it took a bit of head scratching then also. I have had builders suspect the coil splitter, but I have never seen one fail. You are correct, sharing this type of detail advances the movement. I define success in aircraft building as the comparison between what a guy knows going in and how much he knows when the plane flies. Learning isn’t a common goal in all experimental aviation, but it is in the land of Corvairs.-ww

2,850cc Zenith 750 builder CC#22 grad Blaine Schwartz writes:

“William, I appreciate your comments regarding internet builders. I reread some of these posts and it is very clear the author has never seen the business side of a wrench. People just don’t get it: Carl Sandburg once wrote “experience is the best teacher” and there are no words that are more true that. sometimes the truth just hurts. I would much rather seek out the truth based on proven techniques than risk my life on some phony internet expert. Please keep pursuing the pure unadulterated truth for us who use logic in our aviation decision making.-Blaine”

2,850 cc powered Zenith 750 builder/flyer Jeff Cochran (3rd Corvair powered 750) writes:

“William, Every once in a while the photos do not show up on the post. When I click on the icon, it opens a new window that says I am no longer logged on to AOL, and ask me to log in. Would like to see the exhaust photos because I have the same situation. The pilot side has melted some of the fuse skin. I will use your dowel method to bend it down slightly. Meant to ask you about this, so glad it came up.- Jeff”

Jeff, The issue with some photos is that I have taken them out of emails, Grace has a way of correcting this later, but you have to hit F5 on the computer if I sent it out wrong in the first place, sorry about that, I am a troglodyte. Inspect the skin and make sure it’s only paint damage.-ww

Builder Jackson Ordean writes:

” It is the very ‘attitude’ that you exhibit that some folks apparently don’t like is the main reason I tend to believe every word. Don’t change it. I don’t know what to tell ya’ about these guys ‘A’ and ‘B’, except they’re giving the alphabet a bad name.-unabashed fan and future college attendee.”

Jackson, Both A&B are good guys in general, but that doesn’t mean that their advice nor judgment are good to follow. Its OK to be a Fan of the corvair and/or the movement, but I like friends not fans. At Oshkosh a guy told me that I come across as a “know it all” in my writing. I said I was some thing of a “know most of it” on Corvairs. I asked he if he would prefer getting his building information from some one who knew less about the engine or was unsure about their data? I also pointed out that I always tell people I am a caveman, a Luddite, and I can’t paint, fly complex aircraft, sing, dance, do differential equations, be civil with annoying people, or (as Dan Branstrom points out) spell. I am still mystified on how this could be read as being a “know it all.”-ww

On  crash worthiness, Sprint builder Joe Goldman writes:

“How about stress skin construction over aluminum .040 2024T3 oval bulkheads. The Sprint is the same size as the zenith 601 planes, 27ft wingspan, 19′ fuselage. and according to the designer uses 18′x4′ less AL sheets, then the HD601. If I am lucky stall at 38mph@1150lb with 9:1 glide. Off course I have to finish it to prove it.-Joe”

Joe, Sounds like a Sprint should fly a lot like a Zenith 601/650, which I think has a very good combination of factors. The 601s glide ratio was probably higher than 9:1 and is had a low min. sink rate. The Zenith 601/650 are a fairly good STOL planes, even if they are not perceived as such. Woody Harris just told be about landing his at a 1,400′ strip is a very remote part of CA and using less than 1/2 the runway.-ww 

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