Pietenpol lift struts; $65, a free education, and fun with friends..

Builders,

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Below a story in pictures of making a set of steel lift struts for Terry Hand’s Pietenpol. In this previous story: Pietenpol Project – Terry Hand, we had an overview and mentioned he was measuring it for lift struts. Terry lives in Atlanta and drove down for welding assistance in my shop yesterday. He has done me a million favors so it was a chance to repay him in kind.

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The raw material for the struts were a set of pre-war J-3 cub struts, provided to Terry by fellow Corvair/Piet builder Bob “early builder” Dewenter. who found them for $40 at a fly mart. Cub struts are about 2′ longer than the ones on a Piet, so they can be cut down and re-formed. The smaller rear struts had slight bends near the bottom, but they came with good forks and barrels. $40 is a good deal, but not unusual at a flymart, particularly for bent struts which are essentially impossible to straighten, but are good raw material for shorter struts.

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There are several options for material on Pietenpol struts, steel, aluminum, and wood. All have proven themselves to work, but I’m not a fan of wood ones. People point out that biplanes like Jennys and DH-4s had wooden struts, but they are showing they don’t understand aircraft loads, because every strut on a biplane is always in compression, even if the plane is pulling negative G’s. Conversely a lift strut on a monoplane is working in tension almost all of its life, and the tension loads at the strut/fitting interface are a whole different story than a biplane. The weak link on most wooden strut installations are the fittings, and the tear out strength of the bolt holes in the struts. The ornate fittings on some planes look like decorative gate hinges, but they are weak particularly in compression. If you think a Piet will never see 2 negative G’s, think again, loads in turbulence can be that high. I have also seen a set of wooden struts break while a pilot ran down a strip in a wheel landing attitude at 65-70mph with the wing sticking the plane down hard. He ran over a slight rough spot and the lift struts broke in column failure.

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If I teach you one single thing, let it be this phrase I wrote 20 years ago;

“It isn’t the probability of being right, it is the cost of being wrong that matters”

If you are 50% sure your paint won’t flake off who cares; If you are 97% sure your lift strut will not break, it is unacceptable. The first has no serious cost, and the second would likely be fatal. Use my phrase to evaluate things you hear in experimental aviation and you will understand that much of the talk and priorities people have are a foolish misuse of their attention.

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The work on these struts boiled down to removing the bent section on the rears and doing a FAA legit crafty splice ( they are stronger than the original strut) and then putting new wing attach fittings on all four. The additional material as about $25. If a guy can weld, that is the cost for first class struts. If you have a friend who can, good; in Terry’s case he is friends with both Vern (Fun with Agkistrodon Piscivorus and Vern’s Aero-Trike, and Vern’s 5/8 scale L-4..) and myself, so he got two welders for the price of none. Even if you had to pay for the work, it would be worth $300 tops. In Terry’s case it was just some driving, a chance to learn stuff, and a fun day in the hangar, the stuff that makes being an old school traditional homebuilders fun, elements I have worked very hard to retain in our world of Corvairs.

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Above, working with approved engineering. I’m always stunned how people will go to the internet and ask people they don’t know, questions about airplane construction and engines. Often, the advice is dangerous misinformation. What these people should know is aviation is a vast library of known, proven ideas, and there is zero need to ask advice from people with no training nor respect for existing standards or methods. When you are building a plane, you need old and proven, not some fools idea misapplied to aviation. The drawing above is an FAA approved method of splicing lift struts. It is airworthy on certificated aircraft. We used this to take out the bent sections on the lower ends of the rear struts, while retaining the ends with the forks and barrels, which are in great shape in spite of being 78 years old.

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Above, the splice elements of the drawing above, prior to welding. The insert tube is 1″OD, and 6″long.

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Above, Vern on Left and Terry on right. Yes, Vern welds with two pairs of glasses on, I don’t get it but it works for him. To get a look at Vern’s credentials and experience, look at this story: Shop Notes, 10/26/14

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Above, weld splice done. -NEVER, repeat NEVER grind a weld anywhere in aviation. It is a rule from the very first page of the FAA book on aircraft welding, AC-43.13. I have seen many people post pictures of doing this on planes “to make it pretty” including doing this on exhaust systems. In discussion groups this gets lots of “likes” which tells me that people don’t read FAA books on how to do things. The above repair is just to be cleaned and painted. It is not airworthy if a grinder touches it, period. Either you are going to follow proven methods, or go for “Likes” on social media, pick your path, its your life.

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When I post things like this out, there is a certain kind of person who will instantly say ‘it worked on Joe blows plane’ as if that is the standard for how proven methods are developed. All they are doing is citing what one guy allegedly got away with. If someone wants to debate me on a topic, they should pick a one different than aircraft welding, a category I know pretty well.

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The wing attach parts of the spars were fabricated by edge welding 1″ long .188 wall 5/8″ bushings to the edge of 1/8″ 4130 plates. These plates are inserted into slots cut in the strut tops, where they are fine adjusted for alignment and welded in, and then the tops are formed around this core. To start the process, the upper part of the strut needs an accurate slot 4″ deep in the leading and trailing edge. This could be done on a mill, but it only takes a few second on a 14″ chop saw with an abrasive disc.

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Above, a picture of the slot cut into the leading edge of the top of the front lift strut. The plate with the pre welded bushing is slid down in the and checked for alignment before welding. It is an excellent and proven way of transferring the bolt loads from the bushing into the body of the strut.

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Above, Terry cutting the strut end to shape with an air cut off wheel while I clown around taking selfies. I’m wearing a tee shirt from Corvair College #4, which had the slogan “I got my crank polished at Corvair College”, politically incorrect humor for Motorheads and troglodytes.  Airplane building was supposed to be about learning and having fun. If your not getting your share of both, perhaps it is time to plan on hitting Corvair events this year.

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The Next Event on the Schedule:

FlyCorvair/SPA – Joint Workshop/Open house, May 18,19,20

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Also get a look at:

Build a 3.3L Corvair at the May 18-20 Workshop/Open house.

Read the links now and make a plan today.

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WEWjr

Build a 3.3L Corvair at the May 18-20 Workshop/Open house.

Builders;

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We are getting closer to our next event: FlyCorvair/SPA – Joint Workshop/Open house, May 18,19,20. We have already signed up builders of 2700-3000cc Corvairs for 1/2 of the test run slots, but we are reserving almost all of the other slots for 3.3L “Engine in a Box” complete kits. These kits are on the shelf at SPA. If you are considering using one in your plane, the workshop represents a golden opportunity to purchase a kit in advance, and come to the worksop to learning, assembly, and test run. On Sunday you will head home with a great American made motor, a lot of new skills and understanding, and some new friends to boot.

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Get a look at all the links to stories, videos, and pictures of 3.3s. If you decide than you will take advantage of the workshop to make a quantum leap forward on your plane project, call Rachel at the SPA engine hotline to get more pricing and information about the workshop. 904-626-7777.

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A good basic overview of the 3.3L Corvair can be seen here:

3.3 Liter Corvair, a Smooth Power House

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 Above, Dan and Rachel stand on either side of their 3.3 engine at Oshkosh 2015. In the 33 months since the 3.3 has go on the become the ‘engine in a box’ kit, which as been assembled and flown by a number of builders.

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Link to a video of the first 3.3 Running:

SPA / Weseman 3.3 Liter Corvair now running

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A story about vibration testing at Sensenich props on the 3.3:

Testing at Sensenich Propellers

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Story about a 601XL flying on a 3.3L:

Ken Pavlou, Zenith 601XL / Corvair, 620 hours.

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A story about the billet cranks which are the heart of all the 3.3Ls and many 3.0L Corvairs

SPA Billet Corvair Cranks

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A short discussion of the value of a large displacement Corvair

3,300cc Corvair 601XL, Oshkosh 2017

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A look at how the standard baffling kits also clean;u fit the 3.3:

Baffling on 3.3 Liter Corvair 

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A funny story about a test run on a 3.3:  3.3 Liter Corvair of Kamal Mustafa

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In Your Shop: Studio or Cell?

Builders;

Over the last quarter century, I’ve taught perhaps a thousand people how to build an aircraft engine from a Corvair motor. Some of these builders chose to also consider what else I might have to share on the greater topic of aviation, such as these bitter lessons: Risk Management reference page. The words below are addressed to a still smaller subgroup, the builders concerned with how the hours in the shop might protect ones sanity and provide some clarity and peace in a society which values neither. 

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I wrote the words below in 2013. They address what you might find if you treat the hours in your shop as time spent in a creative studio, where you are investing in yourself. Far too many people approach experimental aviation as a consumer experience, and the look at every hour of building as a trade of time for saving the cost of buying a factory plane. These people are sentencing themselves to time in a prison cell.

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As the months pass, the builder who is working in a studio will develop new skills and find the peaceful time to cleanse what modern life soils. He looks forward to the hours of self investment. The customer who’s only goal was to own the appliance will soon discover he is in a prison cell of his own choosing. He will stay only until a frustrating day arrives and he ‘self-paroles’ by quitting the project, unaware that homebuilding had much more to offer than having an airplane. -ww.

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” If you have never met me, but beleive I am charmed with myself, you got it all wrong. I know countless humans who are better people. They are kinder, smarter, and harder working. I can’t sing nor dance, I learn slowly, and I can’t stand to hear my recorded voice nor see my image on film. If I was once handsome, all trace of it is gone along with my uncorrected eyesight. I can be a conversational bore, and I deeply wish I had given my parents more moments to be proud of me. At 50 I look back on my life with a very critical eye and stand on the far side of a very wide gulf from the heroes of my youth.

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Honest evaluation leads to harsh thoughts like that. I spend a lot of time alone and have long bouts of insomnia, which can lead to thinking about things excessively. But here is a secret, shared with anyone who feels the same way at times; I have a sanctuary where I am insulated from much of my self-criticism. It is a place where at 50, I am much better than I was in my youth. When I am building things with my hands in my shop, I rarely feel poor. Although I now need glasses to do any close work, and my hands have lost a lot of dexterity, I am a far better craftsman than I ever was in my youth. I am not a great craftsman, but over a very long time I have worked to develop these elements in my life, and I compete with no one, except who I was last year. While all else fades, these things flourish. It is a gift I am most thankful for.

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This did not come into focus until 1999, the worst year of my life. (The plane crash and burns were 2001, a picnic compared to 1999.)  Feeling dangerously low, I sought the council of a guy I knew. He had come back from such a year. He is an artist, working as an incredibly detailed wood carver. He told me to forget everyone and everything else, go back to my shop and tools and work with my hands. Give up your apartment, but never your studio. Explore all the things you can’t forget, have stolen, give away or loose. At the moment, I was having a hard time picturing surviving another week, and I asked him how long it took him to recover his sanity.  He thought with great care a slowly said “two, no really three..” I was jolted and blurted out “Three months?” he looked me in the eye and said “No. Years. It’s probably your only way out.” It turned out to be a painfully accurate prediction.

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In the years since I have read letters or posts from many people in a tough spot, who are selling their project or tools. I often think their ship is sinking and they have just traded their life jacket for five more minutes on the deck. They are blindly committing a very self destructive error.  I have also met a number of successful builders who have said that when everything else in there lives was broken, they had a place of refuge in work and creation. Of the thousands of people I have met in aviation, these people are truely brothers, for we share the same salvation.”

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Above, a very rare night run of a Corvair engine at Corvair College #22 in Texas. The engine belonged to John Franklin. It ran after dinner on Saturday night, and he had many fellow builders to cheer on his achievement. It was a great moment among builders with similar perspectives.  These hours are a rarity in homebuilding. The vast majority of the time is spent alone.  The quality of these hours is solely determined by the builders attitude, which will determine if he is working in a studio or a prison cell.

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The Next Event on the Schedule:

FlyCorvair/SPA – Joint Workshop/Open house, May 18,19,20

Read the link now and make a plan today.

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WEWjr

Pietenpol Project – Terry Hand

If you like any story here, please feel free to share it with friends. Every story published here also appears on the Corvair College FB page. That makes it easy to share as a link to other friends on FB. I write with the goal of reaching many aviators. I appreciate anyone who shares the stories. -ww

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Builders,

Below is a picture of Terry Hand’s steel tube aluminum spared Pietenpol project. It is in his hangar outside Atlanta. It is an outstanding example of a well thought out, one of a kind, experimental aircraft . For a look at the engine that will power it, read this: Terry Hand’s 2700 cc Pietenpol engine – w/Weseman 5th bearing

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Above, Terry’s bird set up for a final rigging before building the lift struts.  If you like the gear and want to see what first class welding looks like, read: Steel tube Pietenpol fuselage with landing gear and 12 x 4.8″ tires.. The mount on Terry’s plane is a little different because it has a steel tube fuselage, not wood, but it has the same dimensions as out production Pietenpol Motor Mounts, P/N 4201(C).

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Something ironic and retarded about internet comments: Last month, a guy on the web told Terry that the combination of wooden ribs and aluminum spars doesn’t work and the wing would have no rigidity. As a factual source, he citied a guy with no name, in a place he couldn’t remember, some year in the 1970s. I told Terry that I had personally seen a 4 Place, 2,200 pound gross Wag Aero sportsman with the same rib/spar arrangement, fly with my friend Gus Warren at the controls…oh and it was powered by a very angry 200hp angle valve 360 Lycoming. But you have to weigh that fact against a story a guy heard about a unicorn…..

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Are you a fan of Pietenpol’s? So am I, over the years I have spent a lot of time writing factual stories about them. Get a look at this link to see about 30 of them: Corvair – Pietenpol Reference page

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Terry Hand is a very good guy. He runs our Pietvair discussion group: “Zen-vair” and “Piet-vair” Discussion Groups, your resource.. He is also a highly experienced Aviator, with ratings than run from CFI, to ATP, Helicopters, and 767s. Terry is usually pretty humble. I have actually seen him patiently endure a lecture from an inactive private pilot that started with the phrase “when you know more about flying….” You can read some of Terry’s thoughts here: Guest Editorial, Pietenpol builder Terry Hand.

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The Next Event on the Schedule:

FlyCorvair/SPA – Joint Workshop/Open house, May 18,19,20

Read the link now and make a plan today.

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WEWjr

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Steve Wittman – “Like Mars at Perihelion”

Builders:

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There are many greats in aviation, and homebuilding has it’s share, but there was only one life that stands out “like mars at perihelion.”  This is Steve Wittman, greatest air racer who ever lived, builder and designer, pilot of incredible talent. He relentlessly evolved for 70 years in aviation.

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When I was 31 years old, he took me flying in the Olds-Tailwind, N37SW. He wrung the plane out for 25 minutes in a display of skill that I was hard pressed just to fathom. Wittman was 91 years old. Afterward, he took me in the hangar and showed me some new ideas he was incorporating into a brand new set of Tailwind wings he was in the process of building.

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Above, Steve Wittman in his “Buttercup”. He built the plane in 1937. Through out his life he changed many things on the plane, the gear, the engine, the span, the wing tips, adding leading edge devices, making the tail cantilever, etc. Although he was a brilliant designer, and won 375 air races in planes he designed and built, he never rested on his laurels. He was deaf to praise and past glory when there was anything new to try or learn.

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From my 2014 story: Thought for the day: Challenge of an open mind

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The term “Like Mars at Perihelion” is from the essay  Message to Garcia written by Elbert Hubbard in 1899, Describing a hero of the Spanish-American war, Lt. Andrew Rowan.

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WEWjr.

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Corvair / Buttercup – Dan Palmer

Builders,

This is a 2014 photo sent to me by Dan Palmer, the first person to build and fly a Corvair Powered Wittman/Luce Buttercup.  This airframe is one of the all-time great homebuilt designs, from the mind of one of the greatest aviators of all time Steve Wittman.

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Two lessons here:

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If you think that you are too old to build a plane because AARP sends you junk mail, know this: Dan Plamer’s EAA membership number is 3065. Thats right, only four digits. I joined 29 years ago and my number is 331,351.  This guy is serious ‘old school’, he could have voted for Harry Truman. If your first election was after that, time for you to head out to the shop and get building.

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Second, I included his original engine parts order in the picture. Note that it was placed and filled in 2004. Twelve more years elapsed before Dan’s engine went flying. Many planes are a personal lifetime goal, and the builders are not competing with anyone. They may be on a budget, have family obligations, or just approaching each task with a goal of mastery. 2004 was my 15th year in the engine business. Nearly every single engine company from that period is gone. Engine companies that have short life spans don’t serve traditional old school builders. Working with Corvairs since 1989, I am here for the long run. Read: What defines ‘reputable’ in our industry?

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Above, Dan’s creation in New Mexico. The Corvair and the Buttercup are a natural match. Wittman’s original was powered with a number of different engines, but he intentionally stuck with a high reving C-85 installation.

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Today, I find it ironic for anyone to claim to admire Wittman’s designs, but not like auto engines. He was one of the greatest advocates of alternative engines and high rpm direct drive props ever.  I know what I’m speaking of, read this: From The Past: With Steve Wittman 20 years ago today. Wittman’s Oldsmobile V-8 powered Tailwind flew us on a 62″ metal prop turning 3,600 rpm at 195mph. It was no slouch.  His VW powered V-Witt design was the perennial Formula-V national champion.

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It is not a myth that Wittman flew his planes at wide open throttle as a cruise setting, and he liked 500AGL as a cross country altitude. With the props he liked, this meant the original C-85 Buttercup going 145mph with the engine at 3,400 rpm. That is 825 rpm above the C-85s published redline. At 3,400 the C-85 probably made 110-115hp.

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Wittman derided anyone who put a 150-160hp Lycoming in his designs and then throttled back to 115hp for cruise. He may look grandfatherly in pictures, but in person he had a sharp tonge for people who believed old wives tales about slow turning props.  Wittman understood that with the right prop, the 3,400rpm Continental was virtually as efficient and powerful as a throttled back Lycoming, but it was 100 pounds lighter and  less expensive. Everything I have said about the efficiency of Corvair engines with reduced diameter props is taken straight from the Steve Wittman playbook. When you encounter someone making a statement about smaller props not being efficient, recognize they are calling Steve Wittman, the greatest air racer that ever lived, an idiot or a liar.

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WEWjr.

Engine Cores and Parts at SPA

Builders,

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Every airshow has builders who ask about the availability of core engines and rebuildable parts to work with. Below are two pictures I took in the storage building at the SPA/Panther factory.  The images should demonstrate the availability of Corvair core engines, and also point out that we have complete core engines available for builders working with SPA and ourselves.

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Above, one of two pallets of GM 8409 forged cranks to be fully reworked and matched to Gen II 5th bearings. These cranks are destined for base level builds. about 50% of 3.0L Corvairs and 100% of 3.3L Corvairs use SPA’s brand new made in the USA Billet cranks. Read more here: SPA Billet Corvair Cranks. For a look at the three crank options, look at this story: Update notes to 2014 manual, 1000 – Crankshaft group.

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Above, piles of heads, cases, and the end of a row of core motors.  SPA keeps a very large collection of head cores to support their high end Corvair flight head program. They have now made more sets of Corvair Flight heads than any other company, ever. From the start, Dan’s goal was to have them available on the shelf which they now are. In years previous, our former supplier Falcon got to the point of being a year behind. This had not been an issue in the years since Dan started offering heads.

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The cases pictured are mostly from my collection, featured in this story: Corvair Case sale, 36 available, $100 each.. The picture illustrates the availability of parts, and our willingness to invest in them to support builders in a timely fashion.

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Above, a pickup load of complete Core engines I brought to SPA in January. These and others are available for sale now. If you are a builder yet to find a core, but planning on attending the open house next month, it would be a good idea to contact SPA in the next few days to purchase one of the cores we have on hand. All progress on planes starts with the decision that you will take action when opportunity appears.

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SPA=904-626-7777.

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The Next Event on the Schedule:

FlyCorvair/SPA – Joint Workshop/Open house, May 18,19,20

Read the link now and make a plan today.

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WEWjr

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