Category: Installation Components

Posted on

STOL and utility planes for Corvair power

Builders,

Below is an overview of STOL and Utility airframes that have been Corvair powered or are in excellent candidates for the engine, that we have already looked at closely. Included with many of the airframes listed are links to stories about them.

.

This group of planes are all high-wing cabin monoplanes. There is a good selection of designs for builders to choose from. There are others that would work as well, for example Morgan William’s lite star http://www.customflightltd.com/aircraft-kits-1.html Has flown on Corvair power, but I have just written an overview of the planes most people ask about. If you have a plane in mind that you don’t see here, just send me an email.

.

—————————————–

Zenith 750:

This is a good match for the Corvair. There have been a number of them flown in the last four years, and many more are in the works. The 750 has flown on 2700, 2850 and 3000 cc Corvairs. We make every part to install the engine on a 750 airframe and have a Zenith specific install manual. The last link below has a very complete over view.

.

blogburdett050813

Above, the flying 2850cc Zenith 750 built by Gary Burdett of Illinois.  It has our full complement of Zenith installation components and one of our production engines.

.

Zenith 750 Flying on Corvair Power, Gary Burdett, Illinois

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

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

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

 Zenith 750 / Corvair reference page, October 2013

————————————————————————-

Zenith 701:

We flew our 701/2700cc Corvair test bed aircraft in 2007.  The combination works, and a few have been built, but the 750 has stolen a lot of the potential popularity. If anyone is looking at both airframes, they should pick the 750, because it has matched hole tooling and is far easier to build. It is a better match to a Corvair. Economically, a Corvair powered 750 will still cost a lot less than a 912 powered 701. The link below the photo has a very detailed look at the combo. The plane below was made of all our off the shelf engine components, and the entire plane and engine was built in our Edgewater hangar.

.


Our Corvair powered 701 taxis out before its first flight, 2007. Gus Warren at the Controls.

.

Zenith 701- Corvair reference page, November 2013

.

——————————————————————–

Pegzair:

Is a 20 year old Canadian design with automatic leading edge slats. It has a metal wing and a steel tube fuselage. We finished and flew the first Corvair powered on in 2007. the story is in the link below the photo. The engine has all of our conversion components. Every part ahead of the firewall was built in our hangar in Edgewater.

.

Read the story at this link:

3,100cc Corvair in Pegzair

.

—————————————————————

Wagabond :

Below, our Wagabond, N707SV, flying over the Intercostal Waterway near the Atlantic Ocean in 2005. The airframe is based on a highly modified 1964 Piper PA-22-108 (Colt). The plane was built as a group project by “The Hangar Gang” between 2003 and 2005. It has been flown by a number of well-known Corvair pilots who all found it to be a well behaved work horse. In person, the plane is very large for an LSA legal homebuilt. The airframe is the size of a Tripacer, and sitting on the ground the spinner is as tall as I am, yet a direct drive 100 HP Corvair easily flys this plane, including a test flight where the plane climbed out with a payload greater than its own empty weight.

Originally flown to shows by David Vargesko, today the plane has been modified and refined by Grace and myself, re-engined with a 120 HP 3000 cc Corvair, and functions as our personal Corvair powered plane. It is a 5 gallon per hour, 100 MPH plane with a very large baggage compartment. With Grace, the dog, myself and 36 gallons of fuel loaded, it can still carry 275 pounds of equipment and stay in CG.

 .

Below is a youtube link to the plane flying:

http://www.youtube.com/watch?v=B7XhuWmqcPw

.

—————————————————————

Merlin:

Below is a link to film of Jeff Moore’s Merlin flying on floats in Newfoundland. The airframe has a strong following in Canada. This particular plane was originally powered with a Rotax. Jeff’s plane uses most of our Gold engine parts and one of our stainless U-2 exhaust systems. The engine is a 2700 cc motor with a Weseman 5th Bearing.

.

Jeff and the Merlin with Corvair installed.

.

 Film:

Jeff’s story is at this link:

Corvair Powered Merlin Flying Over Newfoundland

.

—————————————————————–

Buttercup:

The plane was originally Designed by Steve Wittman in 1937. It was vastly ahead of its time. Later modified to have full span movable leading edges.  Grace and I worked on the Buttercup pictured below with the intention of finishing it for ourselves before we had a change in direction. Our standard intake and U-2 exhaust fits the plane, along with all of our gold engine components.

Above, the motor mount for our Wittman Buttercup. It is an intensely complicated mount because it incorporates Wittman’s tapered rod landing gear sockets (the modern Buttercup actually uses RV-6 landing gear legs). Earl Luce, the plans provider gave me all the operational data and weight and balance info for his O-200 powered plane, which I mathematically worked out to the Corvair installation. The Mount resembles the O-300 mount for a Tailwind.  After completely welding it, I took it to our local powder coater, and had it done in U.S. Navy gray. It was the 40th different Corvair Motor Mount Design that I have built. Today two builders are closing in on finishing the Corvair Buttercup combination, but none have flown yet. The plane above is being finished in Wisconsin.

.

———————————————————————

Rebel:

The Murphy rebel is an all sheet metal Canadian design almost 25 years old. It is not currently in production. It is a complicated plane to build compared to other all metal designs like a Zenith. Below is a link to a story I wrote about how people who know nothing often say the Corvair will not work on utility planes like the rebel, in spite of all the evidence on this page that speaks to the contrary. The commentary and data in the story is worth reading for anyone looking at a Corvair engine for their homebuilt.

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

.

———————————————————–

Bearhawk LSA:

I consider this plane to be the best flying plane in it’s category. I worked directly with the designer Bob Barrows to develop a Corvair motor mount for it. I flew Bob’s prototype, and it has excellent handling qualities. The design uses or standard intake manifold, and a stainless exhaust common to our Zenith installation.

.

Corvair Motor Mount for Bearhawk LSA

Bearhawk LSA, Corvair motor mount in development

Bob Barrows to Fly LSA Bearhawk to CC #27, Barnwell, S.C., Nov. 2013

.

———————————————————-

Kitfox:

The only Kitfox model that has flown with a Corvair was the model 5. The builder had a number of issues, related to using a poor choice in carbs. Below is a link to a Kitfox 4 mount we made in my shop. The engine is slightly too big for the model 4, but it is a good match for the series 5 and up.  The factory likes to promote engines they sell cowls for and have a dealership on.  Kitfox has had three different owners in the last 25 years. The current ones did not sell the bulk of the unfinished model 5’s which are available second hand from internet sources like barnstormers.com for less than 50% of their original sale price. Combine one of these with a Basic Corvair, and it is possible to build a good plane for less than $18K, airframe and engine.

.

Kitfox Model IV with Corvair mount

———————————————————-

Stits SA-7D Skycoupe:

Ray Stits, the man behind the fabric covering system designed a series of very successful planes in the late 1950s. The Skycoupe was once one of the most popular 2 seat planes in the EAA.  Several hundred were built, and their was even a FAR-23 type certified model. It is a stout plane, but it is small inside by modern standards. We put about 200 hours of flight testing on ours, it is a natural match for the Corvair. Below the photo is a link to pictures of turbocharging the design.

.

Above, the Skycoupe on the ramp in front of our Edgewater hangar in 2007. We made every component ahead of the firewall on this plane.

.

Read more at this link:

More Turbo Skycoupe photos

.

———————————————————–

Fisher Horizon 1 and 2:

Both of these designs have flown on Corvair power. I built the motor mount for them, and most of our off the shelf components fit the installation.  The plane has strong appeal for builders who like wood, but it is not as rugged as steel tube designs or all aluminum ones.

———————————————————–

J-3:

The first plane ever to fly with a Corvair was a J-3 in 1960.  The Corvair would make a very good power plant for any of the J-3, J-5, PA-12 family of airframes.

————————————————————-

Just Highlander:

Below is a photo of the first Corvair/highlander to fly. It was not a success because the builder insisted on using a left over cowl from a Jabaru 3300, and the Bing Carb from the same engine. He also ran the engine was a display without any form of cooling for a long period on the ground prior to the first flight.  With the wrong cowl and carb, it should come as no surprise that the plane overheated. From the pictures above, we have plenty of evidence that the Corvair can easily power larger heaver and slower planes than the Highlander when it is equipped with the correct cowl and carb. .

.

————————————————————

Christavia:

Is an older design that is somewhat similar to a champ. The plane has many fans, but it would not be my first choice in a utility plane. It is called a STOL plane, and it is by Lancair standards by not by Zenith standards. The plane pictured below was powered by a 2700 Corvair with a Rinker Gearbox, a design from the 1970’s. The gear box failed in 28 hours because the machinist employed by the builder decided to omit a keyway critical to the design. The combination will work much better as a direct drive plane.

.

 .

——————————————————-

Taylorcraft BC-12D replica:

Below is a one of a kind plane, built from some BC-12D parts. Today the FAA has cracked down on this practice, but with a friendly DAR this could still be made. The plane below is powered by a 2700 and has clipped wings. It topped out at 130mph.

.

.

This very slick aircraft is the handiwork of Gary Loucks of New York.

.

 

 

Posted on

More Turbo Skycoupe photos

Builders:

While cleaning up some of the older parts of our website I came across a few more pictures of Our Stits SA-7 Skycoupe test bed aircraft to go with the ones that I put on this link: Thought for the day: Being simple and done. The information is applicable to many aircraft.

.

Here’s what the Skycoupe looked like with it’s final cowl, on the ramp in front of our Edgewater hangar in 2007. It had our nose bowl and a Van’s FP-13 13″ spinner. The rest of the cowling is made from flat wraps of aluminum. It does not take much imagination to guess that the airplane was significantly faster with this cowl than the one that came with the airframe pictured at the bottom.  Notice how much more of the prop is working. It’s the same 66″ Warp Drive prop in both photos. It even cooled better. Statistics aside, it looks like a missile, compared to a tugboat. If you’re building a Corvair powered airplane, do not handicap it functionally or aesthetically with an ugly cowling.

.

.

Above is an overhead shot of the turbo installation. It is easier to see the stainless heat shield over the hot side of the turbo in this view. It had a blast tube 1″ in diameter porting cooling air too it off the back of the baffling.  The plane used a stock 12 plate oil cooler, but it did have high oil temps. Note that the plane was built before we had Gold oil systems , Gold prop hubs, or even 5th bearings. It was the very last plane I ever built that didn’t have welded on head pipes for the intake. The value of many of those developments was confirmed by testing on this plane, that is one of the was this plane worked as out test bed. If anyone looks at this photo and thinks about using our old methods, they are not getting the value of our testing from that era.

.

.

Above: One day we brought the plane into the hangar for a maintenance. I removed the cowling and put all the sharp PK screws in a plastic shoebox on top of the wing. Whobiscat, the hangar cat, promptly settled in for a six hour nap. This as not a normal cat. She was particularly cruel, even for a female Siamese, but I found it interesting that she was also cruel to herself at times.

.

Above is the Turbo Skycoupe with its original cowling from a Lycoming powered Pacer. Not a bad cowling if you have an engine 36″ wide. It had come on the Skycoupe when Gary Coppen put the airframe on long term loan to us in 2002. The photo above was taken at Sun n Fun 2005. The modified cowl in the top picture is the one we used from 2006-07.  Every year a hand full of Corvair builders elect to use some off the shelf nose bowl like this one or one for a Continental on their planes and end up with a “esthetically challenged” plane.

.

I didn’t even find this attractive nor functional enough for a test mule airframe we didn’t own. When it had the above cowl at airshows, the first thing we did was take the whole cowl off so people could look at the engine installation. In the same period we had our 601XL and the Wagabond as test aircraft, so we had limited time and call for improvements to the Skycoupe, but eventually we switched it over to our nose bowl and cowl design that we already had on the 601XL and the Wagabond.

.

If you look at photos, the nose bowl also appears on our 750 installations, it is on the Pegzair photos, and variation of the design are on many different Corvair powered planes. If you look at Dan Weseman’s Panther, it uses the same 13″ spinner and the very front of his cowl has the same DNA as our nose bowl. It is a good looking design that works on many planes. -ww.

 .

Posted on

New voltage regulator source. ( #3501)

Builders,

Zenith 601XL builder/Pilot Ken Pavlou sent me this information to pass along to builders. Ken has one of these in his own plane, and it works perfectly.  In our numbering system Group 3500 is the airframe charging group, and part #3501 is the voltage regulator.  This partical manufacturer part number is J4900, made in the USA by Jimco: http://www.jimcotest.com/ . It is Just $65 direct from Jimco.

.

Anytime a part is made in America, works great, and costs 25%, (yes 1/4 the price) of the John Deere part that is made in China,  you can see the hand of grotesque corporate profiteering revealed.  I see countless examples every month where the American made item is actually lower priced than the Chinese one. I bought a Class 3 trailer hitch a while back: most expensive one, Reese, made in China, lowest priced Curt, made in Wisconsin. So much for the argument that exporting jobs was the fault of US labor costs.

.

Visual ID
J4900

PART NUMBER

J4900

Replacement for

JOHN DEERE

AM101406

.

Airframe charging group (3500)

3501- Voltage regulator

3502- PMOV

3503- Master solenoid

3504- Power bus/fuse box

3505- Main electrical pass through

3506- Battery

.

Posted on

New Builder ‘Cards’ and communications

Builders,

Many of you who have met us in person know that one leg of our builder records are on paper. (This backs up of computer records) Grace tends to work with the computers, but I like the Card system. It revolves around how we work with builders; Grace tends to communicate by email, I generally call builders.

.

For example, If I am calling builders in the evening, I generally pull their card out of the files, and review from it the progress of their project, give them a call and cover questions and ideas with them. When I head to an airshow, I bring both existing cards and new blank ones to fill out. I find this a better way to lay out a progress plan with builders picking up or ordering parts.

.

Most builders know about how our full on line catalog also doubles as a checklist for a complete engine build with all the group numbers and the part numbers in each group.  You can see it at this link:http://www.flycorvair.com/products.html. But, it is a long 10 page print out with a lot of detailed info. The Builder card is an abbreviated version of this, stripped down to just list the most popular parts that builders get from us. It leaves off all the items that come with the core engine, come from other sources like Clark’s Corvair or the Wesemans and the ordering notes.

.

Yesterday, Grace and I spent a two hours revising the card to reflect all the most current part numbers. As you are giving it a look, keep in mind that the total of the prices listed is very high if totaled because several choices for systems are listed. Example, both E/P and E/P/X distributors are listed, but your engine needs only one. Likewise, there are four stainless exhaust systems listed, but obviously a plane needs just one. If you are looking at the Card and something isn’t clear, the first stop is back at the main catalog page, where the descriptions are expanded and there are further notes. I wanted to give new builders an advance look at things they will likely need from us.  Note that some items don’t have prices, these items are place holders that may be developed later.

.

 

EngineBuilderCard1060614

tying

 

EngineBuilderCard2060614

Here’s a link to a pdf which might be easier for some to print:

EngineTwoPageCard060614PDF

.

——————————————————-

.

Communications:

.

In the last 90 days we have been hit with both, a number of family obligations and a deluge of email and calls. The family obligations are the same things that nearly everyone faces at one time, and we appreciate the people who expresses understanding. The Email has been caused by a string of favorable magazine articles and interest coming off the four 2014 colleges. I understand that it can be frustrating at times to work with this, but we are putting great effort into getting back ahead of the curve. The new builders cards above are a very small part of a comprehensive re-organization, all done to make things work smoother. I have taken behind the scenes, but real, steps to prioritize existing builders. If you are a builder who I still have to call back, you may not feel this yet, but we are working on it.

.

A while back, I wrote two stories that explained how we are a small mom and pop business in an industry characterized by big flashy, often short lived outfits. We have a different mission, approach and capability. For people who can meet us half way, there are rewards you can’t get from salesmen. The two stories are: Back from the road, notes on Communications and Improving communications……a little reading goes a long way. Below is an excerpt from the first story, it is the most important element that builders can do to help things work better:

.

“When leaving a message, please leave me a number that I can call you on in the evening, and how late I can return your call. I can cover a lot of calls in the evening. I often spend several hours between 7 and 12 pm answering questions in great detail.  You are always welcome to call 904 -529-0006 as late as you like. It only rings in the hangar, and it will not disturb us if you call late. About 1/2 the nights of the week I am in the hangar until midnight. If you ever ring the phone and it tells you the mail box is full, it is an electronic fluke caused by me not having call waiting, but also having some type of phone company complementary voice mail that I don’t want. This message just means I am on the line with a builder already.

.

The absolute best way of contacting us: Send me a short email that looks like this:

“Subject:  Corvair engines, question from Bob Smith

Bob smith here: Please give me a call back on my house line 608-123-3456 or cell, 608-234-5467 any time up to 8pm CST. I have a number of questions about a Zenith 750. Thanks.”

.

 

 

Posted on

Aircraft Wiring 102

Builders,

After todays Aircraft Wiring 101 story, a letter came in from California 750 builder David Josephson. I share it for several reasons;

.

First, it is a view of what a builder can do if he wants to look at operating one level above the basic information I was sharing.  In all my conversations with David, what comes through is his unusual balance of technical-practical-detail application along with a very strong scientific understanding of the fundamentals of the question at hand.  When reading his take on a subject, it is a reminder that accessing this balance on any subject is what makes it interesting. While Tefzel and basic quality crimps and tools are what I use on planes, David’s notes are another step toward quality and away from the sub-airworthy.

.

Second, The letter is a reminder to people who work outside Aviation or the tech world, that industry specs and standards mean something in our field. Many workplaces and topics have very subjective standards of performance or none at all; note that experts in aviation long ago put out the most detailed standards for things as small at how wire is plated. Working in aviation, I don’t know 2% of these standards, but critically, I know for almost every question, there is a correct tested answer, you just have to look for it.  Understand when a guy says “It will be alright” what his is actually doing is deciding to stop looking for the known way and proven path, and accept the item in question as it is. Conversely, a guy who works in aviation knows that when in doubt, keep looking until you find the proven standard. When you think like that, you have become an aviation professional, even if your paycheck has a different address.

.

Third, The strength of the Corvair movement is the quality of the people we bring in as builders. Yes, I know the subject of Corvairs very well, but we have countless other people who know far more about engineering , electronics, flight, you name it. I like it this way, because it puts me in contact with people a lot smarter than me, and this expands my world and learning.  At Oshkosh a number of years ago, I was confronted by a man who leveled what he felt to be a damning charge against me; He wanted to publicly prove that I had changed my position on several technical points over the years. He was perplexed and disappointed by my response, where I told everyone present “Yes, I intentionally surrounded myself with smart people and then had the common sense to listen to them.”

.

c79323

Oshkosh 2013: East meets West in the tent. Two of the sharpest minds in the Corvair movement belong to Ken Pavlou of Connecticut, at left above, and David Josephson of California on the right. Both are Zenith builders. Ken has been involved in numerous projects in support of the Corvair movement. David is a nationally known expert on acoustics, and is interested in extreme noise reduction in aircraft. Both of these men find the Corvair movement the right focal point for their efforts in aviation.

.

____________________________

.

"William,

I have a few comments on your article, and a resource to offer. Your
recipe is good, but if people want to drill a little deeper they can
understand a bit more if they want. A well designed simple airplane will
only have a few dollars of wire in it, there is no point in scrimping —
but it may be possible to buy NOS military wire and terminals and get
good quality for less.

1. The softness of the terminal insulation is only part of the picture.
Good crimp terminals are made with nylon insulating sleeves, which is
soft and transparent. More important, there is a bronze sleeve inside
that crimps around the wire insulation under the nylon to actually
provide strain relief. The terminals with vinyl sleeves lack this part
and no strain relief is actually provided, only insulation, because
there is no mechanical connection to the insulation of the wire. Good
crimp terminals are made by Thomas and Betts, AMP and Panduit (although
those companies also make cheap vinyl insulated terminals that have no
strain relief,) and are compliant with the former MS-25036 series, now
SAE AS 25036.

2. The crimp tool must be the one specified by the manufacturer of the
terminal or compliant with the relevant mil spec, such as the AMP tool
in your picture.

3. An even more secure approach is to use uninsulated crimp terminals,
soldered if you like, and heat shrink tubing, which if clear can include
a typed label inside. (But! Solder only after there is a secure crimp!)
The crimp tool for uninsulated terminals like the original T&B Sta-Kon
is completely different from that used with insulated terminals.

4. The wire doesn’t have to be Tefzel (crosslinked ETFE), but it does
have to be aircraft wire. There are three criteria: the strands must be
individually plated, not bare copper or batch tinned, the stranding must
be fine enough to provide good flexibility, and the insulation must be
rugged enough not to deform when clamped, rubbed or mildly abraded.
Generally people use Tefzel because it can get hotter and not smoke
versus PVC, but the fumes from burning Tefzel are worse than from
burning PVC. Tefzel wire compliant with MIL-W-22759 is the best
compromise but is expensive. It comes in many colors and is stamped with
the mil spec number and gauge. PVC is okay but it must have a nylon or
fiberglass jacket, typically compliant with MIL-W-5086 or the later
MIL-W-16878. There are also good aircraft wire made to Boeing
specification. Teflon (PTFE) is okay inside equipment, but is softer and
more easily damaged. Teflon also more expensive than Tefzel because it
is usually silver plated — and in many cases the silver plating on
surplus Teflon wire has tarnished so badly you can’t use it.

5. There is a good stock of surplus aircraft wire, $8 a pound for mil
spec vinyl and $15 a pound for fluorocarbon (when in doubt they charge
you the vinyl price,) at Apex Electronics in southern Calif.,
www.apexelectronic.com. Joe has come back from retirement and will
usually find what you want, better if you go there. They also have
multiconductor milspec cable. They have mostly 16 gauge and smaller, I
recently bought spools of 16 and 20 gauge and even at $15 a pound it’s
1/4 the current market price, and you have a chance to get it in colors
if you are lucky. It is worth a visit, it’s one of the remaining
aviation surplus stores on the west coast. Take a flashlight and good
glasses, the lighting inside isn’t so great.

6. The Delphi Weather Pack connectors are great, *if* you buy into the
whole system. The parts are cheap, but you need to have the correct
sealing glands and the correct crimp tool or the reliability of the
system is lost. If you really need to be able to disconnect things
quickly, fine. Frankly I prefer to have fewer connectors and am willing
to spend a little more time unscrewing terminals.

7. NO BARREL SPLICES. You cannot inspect the crimp of a barrel splice,
so you have no way of knowing it’s secure. If you need to splice a wire,
use two knife blade connectors like AMP 32446, in a length of vinyl
tubing tied with nylon twine.- David”

.

Posted on

Aircraft wiring 101

Builders:

I bring this up because it is the most common mistake I see in homebuilding, and oddly enough, it is about the easiest skill to posses, the tools are cheap, and there is no valid reason for doing this wrong……but 75% of the planes I look at have terrible wiring, particularly the terminal crimps.

.

Below is a photo that has been on our main page for nine years. It is also in our Zenith installation manual, and I have reprinted it before. Search “wiring crimp” on the main page search block and it pops right up. Think most people read it? The wiring I see suggests otherwise.

.

This isn’t an academic nor style point, this is airworthiness 101. Two years ago we had a builder spend several months of very frustrating searching, looking for a defect that made his plane have a bad miss at times. He sent the distributor back to me more than once with the clear implication that it was defective even though it tested fine. Next suspect was the certified yellow tagged carb. All the while, the people at his airport are being treated to a demonstration they perceive as “Auto engines are unreliable” and “Not even the guru knows how to fix it.” When it was all said an done, the 100% culprit was a shitty crimp done by the builder on the 12V line going to the coil. I do not like my designs and work being considered as the prime suspects when the issue is people who are doing wiring at a quality we could expect from a weed smoking high school boy in 1978, trying to install his 8-track player in a ’69 Valiant, so he could listen to his new Ted Nugent Cat Scratch fever tape.

.

Your Corvair needs good wiring on the ignition system to run properly. You need to make as few connections as possible, and have a simple design for the critical wiring. Leave out all the junction strips and additional connections. To make the distributor easily removable, consider using the Weatherpack connector we have on EP-X distributors. If you are headed to a college and already have a distributor, bring it, I will upgrade it on the spot.

.

Now, as we read this, some dope is going to post a link on a discussion group saying that “Corvairs have critical wiring and that is why I am glad I picked an A-65 Continental with mags.” OK, get this: Hand prop planes with mags have an even more critical connection than a Corvair. The P-lead grounds to the mag have to be done perfectly, because you count on them to protect your life every time you touch the prop.  If one of the P-leads has a shitty crimp, the key can be in the off position and the engine will easily start or kick over with lethal force.  Think I am exaggerating? At the very bottom of this story are a few photos of a great guy Gary Collins, who attended many Corvair Colleges and built a very nice Corvair Powered Carlson Sparrow II. In June of 2013 he was struck by the prop on his Lycoming O-320 powered Tailwind while simply working in his hangar. He died several days later.

.

I want to clearly state that I am in no way implying that Gary’s plane had anything wrong with the wiring or he that was an unsafe guy.  He was an outstanding human being, and I include his accident here because I want to make builders understand that accidents involving props are not a myth, and they do happen. (Gary did not build nor wire the plane that killed him) By putting a person’s name on one I want people to think about this as possible. I have seen a number of homebuilts with poor wiring and magneto ignition. You can assume the builder also did poor work on making the P-leads. Moving such a plane by touching the prop, or rotating the prop to prime it is the absolute equivalent of pointing a loaded gun with a known defect in the safety at your head.  All planes have critical points where the wiring quality must be 100%. Anyone who implies it is OK to have “It will be alright” level of quality on the P-leads of planes with mags is a dangerous fool.

.

Go on any internet forum on homebuilding you like and bring up the topic of wiring. You will get hours of reading and opinion on electrical theory, written by people who think they have something to teach Nikola Tesla. It is all a giant waste without simple crimping tools and skills, but the armchair electrical engineers never bring that up. Good homebuilding is about mastery of basic skills like crimping. It is that simple.

.

———————————————————

.

Here are the basic elements of good wiring for experimental airplanes. Tefzel clad wiring is available from all the  aircraft supply houses. This jacketing is many times tougher than typical insulation, especially at elevated temperatures.  Real aircraft grade terminals have soft insulation, which does not crack when it’s crimped. The crimpers in the photo  above are available from mcmaster.com. They’re just under $50, and worth every penny. There are many good books on  aircraft wiring, and some discussion groups about it. Unfortunately, most Internet discussions devolve into giant debates about  massive redundancy, counter EMF, diodes and bridges, and how the letter i represents the square root of -1, which can  be used to describe the behavior of alternating current. Perhaps you, like me, get sleepy reading this stuff and wonder  what it has to do with your airplane. Answer is: not much. But do not wholesale cash in all of aircraft wiring. The  basic materials and tools are important to incorporate into your own project. Don’t let the complex discussions  completely turn you off.

Above are things that should not be in your aircraft workshop. Typical automotive store wiring has very soft, poor  insulation. The crimpers do a terrible job, and the terminals have hard insulation that cracks when crimped, and is  then prone to falling off. Wiring like this is one of the first things that catches my eye when inspecting a project or  scanning a photo. Your DAR, when inspecting the airplane, will notice this also. Many DARs I know are very reluctant  to sign off airplanes with this type of wire. Five minutes of exposure to the right stuff and you’d never consider  using the wrong stuff again.

————————————————–

.

The following excerpt is form a story I wrote called Spark Plug Issue resolved….. you can click on the title to read the whole story after reading and thinking about the words below. It is fine to have dreams and complex interests in aviation, but you must also strive to cover the fundamentals. like being able to do a 100% airworthy crimp. Being able to fly a jet is an admirable skill that takes real effort to learn, but in successful homebuilding the basic stick and rudder guy who spent 30 minutes learning how to do good crimps is going to have a lot more success than a 10,000 hour jet pilot

.

“In an average year, I will get 200 emails asking about things like constant speed props and elaborate injection systems. If you read all of them, it is easy to tell that 95% of these come from people with little experience. If I lined up these 95% and asked them to install a distributor and time it, or to explain to me how you could tell if the engine was on the top of the exhaust stroke of compression by looking at the motion of the rockers,(both things we teach at Colleges,) I am sure these people would be at a loss. Is there anything wrong with their dreaming of injected constant speed planes? Of course not…if the extent of what they came to aviation to do is dream about things. Conversely, if actually achieving things is the goal, dreaming can not take the place of a rock solid foundation of the basics.

None of us were born knowing this stuff. I am glad to teach it to anyone who wishes to learn instead of day dreaming. I can make a very good argument that the builder who creates and masters the operation of a basic aircraft, is a lot safer, and will experience far greater rewards that any builder operating a plane he really doesn’t understand, or is sketchy on the details of a complex aircraft’s function. The guy with the most basic plane has won the game. The guy who consigns himself to daydreaming has not lost the game…..he wasn’t ever playing.  Once the basics are mastered, then moving forward can be done with the understanding that you are not posing or posturing as your own mechanic, you actually have earned the confidence in yourself, the real reward for knowing the subject. -ww

.

—————————————-

.

I took the comments below from Gary Collins’s Facebook page. They were written by his son in law as Gary lay dying in the hospital. Learn from this tragedy. Gary was a life long aviator with a very safety minded attitude. I worked with him at many Colleges, and I would never have suspectled he would have this type of accident. Learn to treat props with the same care you handle firearms.

.

 “I will miss you Gary.  You have always been very generous with me and Jennifer and the girls.  I enjoyed the time we spent together.  I pray that you can still hear the words of love that your family and friends give as they visit you in the hospital.  I pray that you have no pain or discomfort in your last days.  And I pray that you find peace with the Lord so we can see each other again someday in heaven.  God bless you.”

Photo

Photo

Photo

.

Posted on

Myths about propeller efficency

Builders,

On the Pietenpol discussion group, a well meaning guy reposted a story from the 1996 Pietenpol newsletter. The subject was on prop efficiency. It included the comment:

“The Corvair engine is another compromise. They have a loss of efficiency due to the small diameter propeller and accelerate poorly (due to the tall gear effect) but produces good power. ” 

The guy who posted this probably didn’t know it, but I know that the comment is without merit, and no one who actually conducted a test, or understood propellers would make such a comment. Yet, here we are, 18 years later, in the information age, following the same myths that have been floating around for decades.

.

The above comment has no educational value. Take it line by line: All engines, not just a Corvair are a compromise, period. Testing shows that a 100HP engine climbing at 60 mph with a 66″ prop may be close to 95% as efficient as one with a 72″ prop; Ask any tester you like, there is no such thing as an engine that produces good power but accelerates poorly. This only happens when it has a bad prop on it.

.

OK, the whole point of having a dialog, reading thoughts or communicating about the building of planes is to learn something and use this knowledge to improve the plane you are building. The comment above serves none of these functions. It is only valuable to people who which to reinforce false realities they believe in. You can divide almost every story you read that allegedly shares information on airplane building into to camps: Valid testing that supports learning, and opinion or out of context stories that support myths. Only one of these will make your plane better.

.

This division cleaves all discussion, any story can be put in one pile or the other.  What always gets me is this simple fact: Less than 20% of homebuilts are completed. I have been around Pietenpols a long time, and I would guess that their completion rate is far below 10%. What no industry magazine or salesman is going to tell you is that the completion rate, as a whole for our branch of aviation is actually dropping. Yes more planes get completed, but the sell many more these days. Given this fact, you would think that builders would all recognize that to personally beat the poor average, they have to make some smart choices, and a critical one is learn from valid tests, and don’t waste time listening to the same myths and old wives tales that lead 80% of previous builders to failure. But, for some reason, the myth mill still works every day, and people participate in it, directly sabotaging their own chances of learning and success

.

It is somewhat frustrating to conduct a mountain of public tests, but they are cited less often than dubious sources from decades-old news letters. For people who wish to see real side by side thrust tests and dyno runs, get a look at this link to our testing page: Testing and Data Collection reference page. For Pietenpol builders who want to see that a 72″ prop doesn’t hold a candle to a 66″ one bolted to a powerful engine, look at: Pietenpol Power: 100 hp Corvair vs 65 hp Lycoming. If you would like to read about how most of the things said about “prop efficiency” are myths, get a look at this:The case of the Murphy Rebel, “eyeball vs. testing” I would hope that the next time the myth machine goes to work, someone will share a link to these pages, or even this story.

.

Here is a simple example of testing and common sense from the last story link:

“Props with diameters of 74″ are only efficient on engines like the
Continental 65 with a low red line of 2300 rpm. Low rpm isn’t efficient in itself. A 65 Continental becomes a 75 continental with respect to power output by just a jet change and an RPM increase to 2600.  If turning the prop 300 rpm faster and using one with less diameter actually made less low speed thrust, than no one would have ever converted a 65 to a 75.”

Some pretty basic logic. I only ask people to believe what I can show them with tests and common sense like the point above. To counter this, the myth makers only have old newsletters and stories like “I heard a guy tried that once but it didn’t work.” Occasionally there will be input from a guy who touts a long dusty engineering degree as some credential as credibility for his favorite myth. If that is more valid than a specific test done in public, then I have a Unicorn to sell you.

.

If you would like a simple example to destroy the myth that low speed aircraft have to have large slow turning props to have performance, let us take a look at some work from a man who only valued one thing in planes: Performance. This man was the greatest air racer who ever lived, and almost all of his work was done on planes that could be well powered by a Corvair. The Mans name was Steve Wittman.

.

Let’s look at the plane below and the prop on it. It is Wittman’s “Big X”. It is a 4 seater powered by a 150HP Franklin. It was noted for having a very wide speed envelope.  Did Wittman use a big slow turning prop said to be efficient? No, he used a high rpm, smaller scimitar prop. This plane climbed at 70 mph, it had to have good low speed thrust, and it did. How long have people known that the only thing slow props have going for them is sound suppression? Well the photo here is from 1947.

.

Below, the Buttercup. The photo is from the EAA museum where the plane was retired to after flying for 60 years. It is reported to have 3,000 hours on it. The prop is not the correct one, it is just for display. This plane will fly and climb at speeds well below the stall speed of a Pietenpol. it will also do 145 mph on the top end. How does it cover such a wide envelope with a C-85? Simple, it has a smaller diameter prop that it spins faster. For people who claim that high rpm props don’t make thrust, please explain what was making the thrust that drove the plane forward at 145 mph when the engine was turning 3,400 rpm. Again the ideas are not new, the buttercup was built in 1937.

.

How about a slightly faster example? Below is a youtube link to Steve flying his Tailwind N-37SW, powered by a direct drive inverted Olds 215 V-8, bored and stroked to 262 cid. It has a 62″ diameter prop on it. It was cut down from a Cessna 150 aluminum prop. It climbed very strong and topped out at 3,600 rpm and 195 mph with out wheel pants. How do I know this? Because I flew in the airplane with him for a very vigorous flight in 1993. Notice that people who present myths always have a mysterious “guy who tried it”. I am essentially doing the same thing here, with the exception that I was there, my “guy” actually existed and was one of the greatest builders and pilots of all time, and, conversely, it worked for him. Other than those details, my story is just the same as any other internet myth.

http://www.youtube.com/watch?v=WsH-j4pF4fE

.

_________________________________

.

Something I wrote about real aviators at the core of flight:

.

“If you look at their lives close enough, all of the greats offer something to guide us in pursuit of the timeless truth of flying. Pietenpol teaches that we are more likely to find it in the simplest of planes; Lindbergh knew that you started your search inside yourself; Gann said that we will not see the truth directly, but you can watch it at work in the actions of airmen; and Wittman showed that if you flew fast enough, for long enough, you just might catch it. These men, and many others, spent the better part of their lives looking for this very illusive ghost. Some of them paid a high price, but you get the impression they all thought it was worth it.

While it is possible that someone who rents a 172 or even a person who reads Fate is the Hunter has some access, I honestly think that the homebuilder who dreams, plans, builds and eventually flys his own plane is infinitely more likely to experience the timeless truth of man’s quest for flight. All of the aviators who had some insight to guide you found it while they were in action, in the arena. If you inherently feel that you want to build a plane, you feel just like Pietenpol did. When you’re building it, you will find out how determined you are and what kind of perseverance you have. Lindbergh evaluated these qualities in himself every day. As you finish and prepare to fly, you will find others of enormous qualities and flaws, and you will learn to sort them and their counsel, as Gann always did. And when you fly your plane, and come to trust it because it is your creation, and you cut no corners, you will never want to stop, the way Wittman never did.” -ww-(2008)

Posted on

Prices going up Monday night 2/24

Builders,

Since the beginning of the year I have been conducting cost reviews on all of the parts and services we offer. Over the last few years we have slowly evolved a number of our products without raising prices. Additionally, a number of our machine shops have slowly raised their prices to us. To address these issues, we are going to modestly change many, but not all the prices on our catalog page: http://www.flycorvair.com/products.html.

.

Keep in mind that being willing to do work yourself has a very large effect on the cost of your engine.  If an engine importer raises his price, that’s it, pay it or don’t progress. With our program, the majority of the cost increases we are implementing address the fact I have severely underpriced our shop labor rate.  Most aircraft maintenance shops bill at $80/hr., which is still less than most people pay to have their car worked on.

.

After building small batches of parts like starters and oil covers without interruption, I found out we were working on some parts for under $20/hr. Obviously we are not going to have a 400% price increase, but we do have to change some things.

.

Keep in mind you can’t actually complain about my shop rate if I am willing to come to your state, hold a college and train you for free to do the same work on your own engine, and then supervise you doing it and test run it for you. I have always trained guys to do as much as they like on their project, but if you would like to leave parts of it in our hands, it is going to be slightly more expensive after Monday night.

 

.

The change is going to go into effect around midnight on Monday the 24th. We are sending this out so builders who were thinking about getting a particular item can order it before the increase goes into effect.

.

If any builder has a question on any part, please email me with you phone number and a time I can call you back. We are starting to pack for CC#28 in Texas, but I will make time to get back to everyone on Monday.

.

Again, I would like to remind builders, that having an “order” with us means that the builder has sent payment or paid on line. In the case of complete engines, it means we have a deposit for your engine on hand. We do have people who just send us an email saying “bring a mount to Oshkosh for me …flyboy26ataol.com” That does not constitute an order. I would need an army of mechanics and a fleet of 18 wheelers to make and bring to Oshkosh every part anonymous people said they were going to buy. More realistically, we try to focus on regular orders made through regular means.

.

Exemptions:

1) If you have a part on order with us, it will be delivered at the original price.

2) If you are one of the 4 people who have an engine ordered with us, and you have sent us the deposit without specifying all the options on your engine, the engine options will be priced at the original level, even if you specify them later.

3) If you have a part in the shop, like an engine in for a teardown inspection, and we quoted a price, it stays where quoted, even if the work is yet to be paid for.

Posted on

Pietenpol Weight and Balance project

Builders,

Besides covering the world of Corvairs, I have done a number of additional projects in Experimental Aviation. One of the most important of these other projects was the Pietenpol Weight and Balance project, 2010 -2012. We did this project to serve all builders of this design, not just the builders using a Corvair. The work was covered in a series of five articles in the Pietenpol newsletter. There is information at the bottom of this story on ordering the back issues.

.

Above, My Pietenpol at the last hours of Sun n Fun 1996. From L to R, Gus Warren, Steve Upson and a much younger version of me. I have been around Pietenpols my entire 25 years in aviation. Take a moment to look at all the aspects of this on our Pietenpol page at this link:

Corvair – Pietenpol Reference page

.

__________________________________________

.

The nature of the issue: People who know the design well, understood that a great number of these planes were being finished and flown near their aft CG limit or behind it. This is a dangerous situation. The problem was driven by a number of factors: people using light engines like A-65’s, pilots who are far past the 170lb FAA example, and the fact many people had no examples to follow, and operated on old wives tails. The Aircamper is extraordinarily sensitive to poor planning because the pilot sits entirely behind the rear spar of the wing, much further aft than a typical tandem cockpit light plane such as a J-3.

.

Additionally, many planes were built with their main landing gear too far back. This lead to several airplanes being put on their backs. Combining axle placement from 1930s drawings with modern brakes caused this.

.

Although there had not been any fatalities directly attributable to CG and axle placement, there had been significant preventable damage done. I also suspected that the poor utilization of a great number of finished planes was due to the undesirable handling caused by these issues.

.

A weight and balance document that Bernard Pietenpol developed in the 1960’s with an example of showing correct axle placement for brakes, an example of W&B that allowed a 290 pound pilot to be in limits, and stating in all capital letters that the CG of his design was 15″ to 20″ and that it was never to be flown aft of this, was available, but largely ignored by builders. Additionally, I weighed “The Last Original, ” Bernard’s personal plane, confirming his design data. I can think of no other design where builders routinely ignored designers CG limits. Our goal was to demonstrate that there is no reason to.

.

The project was done with the support of many well known Pietenpol people like Doc and Dee Mosher and Bill Knight. We also had great participation for pilots who allowed us measure their aircraft and weigh them. The project had broad support.  A gentleman who was personal friends with BHP told me that it was the single most constructive project undertaken since Bernard had passed in 1984.

.

———————————————————–

.

The data collection: In 2010,2011 and 2012, I brought a set of very accurate electronic scales to Brodhead and weighed more than 30 different Pietenpols with Corvair Ford and Continental  engines. All of the measurements of the aircraft, such as fuselage length, motor mount length, landing gear location and wing to fuselage location were accurately taken. I used the same set of scales every year. A number of the aircraft we weighed had very poor bathroom Scale type W&B reports. Several planes had not been weighed in years, or were purchased second hand and had W&B data that was clearly copied from a different aircraft. About 1/3 of the aircraft had flown to Brodhead at or beyond the designs 20″ aft CG limit. All of these pilots expressed thanks at learning the situation and made plans to correct it.

.

The data showed many parts of builders lore to be foolish myths; Both long and short fuselage models were shown to be equally prone to CG issues;  Fuel and passenger weight was shown to have little effect; we proved that building a longer engine mount had very little effect on CG compared to wing placement; Lighter was not better, as the lightest planes as a group had the most aft CG.

.

We did additional measurements on planes in 2011 and 2012. I used the same scales in Florida and South Carolina to measure several other planes. The total data set is now 33 aircraft, enough to cover the design thoroughly. For an example of a specific CG change and performance change in a Pietenpol going from a 65Hp engine to a Corvair read: Pietenpol Power: 100 hp Corvair vs 65 hp Lycoming.

.

68209

Bob Lester strikes the “Intrepid Aviator” pose with his Pietenpol.  Bob weighs 210 fully dressed up for open cockpit flying. with his Lycoming, his plane was flying near the back of the CG range at 19.1″. With the Corvair we moved it forward to 15.9″ This is a dramatic shift, and it would now take a pilot over 320 pounds to move his CG to the aft limit. This is a much better position to be in.

.

The project was started at Brodhead 2010. With the help of the above crew,  we performed a weight and balance on 14 Piets. From left to right above, Ryan Mueller, Jess (whose shirt says “Real men fly  Pietenpols”), Emory Luth and myself.  Gathering the data was a quick process,  taking less than 10 minutes per plane once we had the drill down.

,

______________________________________

.

The calculations and results: Technically every pilot and A&P must know how to do a weight and balance calculation to pass his test. The reality I know is 50% can’t do a weight and Balance calculation to save their lives. On the other hand, I am particularly good at this, especially the complex variable of adjusting the wing fuselage location to correct the issue.

.

One of the first things Ryan and I did was develop a complex computer algorithm that we could plug each planes data into and it automatically spit out the maximum pilot weight that the plane could take before it went out the aft limit of the design at 20.” There were several planes we measured that had A-65 Continentals that could only take a pilot of 130-135 pounds before going out the aft limit of the envelope. Several of these were being flown by 180-190 pilots. You can get away with this as long as you have the engine running creating high air flow over the tail, but if the engine quit and the speed decayed, the plane would be very prone to an unrecoverable condition.

.

Rational people do not build airplanes to see what they can get away with, they do it to effectively master the skills and utilize the design correctly. Anyone arguing that it is “OK” to build and fly a plane at or beyond the CG limit because he has evidence that it has been gotten away with before isn’t a person who should be taken seriously, and their judgment can rightly be called into question. Using our data, any plane, even one with a light motor can be set up correctly to fly with a pilot of 220 pounds. Planes using a Corvair, Ford or O-200 can be set up to fly 300 pound pilots in CG.  Several of the examples we weighed could have pilots over 305 pounds and still be in CG. There is no reason to build your plane and not have it operate in the designers CG limits.

.

______________________________________

.

Where you can find the full data set. Click on this link:

Pietenpol Weight and Balance article source

.

__________________________________

 Most people don’t view it as their task to correct negative or dangerous things others advocate. They value “getting along.”  For a reason explained below, my loyalty lies elsewhere.

.

I earned my A&P license from Embry-Riddle in 1991. It was in an era when the department was run by men who were former military, who had come of age in WWII,  Korea, the Cold War and Vietnam. They took aviation very seriously, they all had seen its potential costs. They were tough.  I am biased, but I do think the program was without peer.  At the end of training, a handful of select students, I among them, elected to take a solemn oath in a private ceremony  to swear our unwavering allegiance to aviation safety.

.

We did not swear to protect our employers, nor to defend the FAA or their rules, nor did we swear to defend our friends, careers or egos. We didn’t even take an oath to protect pilots. The only people we were taking an oath to protect was unwitting passengers who would fly in planes, people who had supreme trust and the belief that their fellow man, an aviation professional, was trustworthy with their very life.  The critical element of the oath is that we might be the passengers last line of defense, and if it was so, we were to “forsake every other consideration to protect them.”

.

To have some understanding of my perspective, spend an evening reading my Risk Management reference page.  If you only have some time, just read this story: Effective Risk Management – 2,903 words ” It include the statement “This was the first time I can clearly say I understood the cost of keeping your mouth shut. This was the first step to me becoming the kind of “Bastard” who publicly points out people doing dangerous things.” At the conclusion of the CG project I wrote the paragraph below when a builder sent me a photo of an 8 year old kid flying in a plane with an aft CG. Few people outside professional circles understood the tone, but I did get one short note from a guy who graduated from Embry-Riddle before I was born, when the school was still in Miami. He knew without asking I had taken the oath as he had, and the tone made perfect sense to him.

.

” Many builders over 160 pounds with light engines are actually flying behind the aft CG limit, which is a great idea if you feel you have already accomplished every thing you wanted to do in this life. In my book if, you want to knowingly fly out the aft cg limit of a homebuilt, it’s your choice, I don’t base my happiness on the actions of others. If someone wants to tell other people this is a good thing to do, then they will find me disagreeable. If a guy wants to go a step further and fly passengers who know nothing about CG, like little kids, they will find me to be a vocal opponent of theirs, no matter who they are. When it comes to speaking up for the safety of unwitting passengers, I am not intimidated by any combination of the offending pilots wealth, experience, popularity or physical size far less peer pressure or being thought of as a mean spirited sob.”

Posted on

Mounts at Oshkosh and Colleges.

Builders,

In the last few days we have had a number of questions on ordering and picking up mounts at airshows and colleges. We are always glad to save the builder the shipping on a mount by delivering it in person to an event. A few guidelines make the process work smoother, and several of the letter’s questions can be covered here.

We have two different categories of mounts. Some we build in big groups just to have available, others are in small groups or done one at a time. For the most part, the Zenith 601/650 mount (4201-A) and the Zenith 750 (4201-B), we build in groups 4 times a year. Typically, we have several extras heading to a show like Oshkosh, but the surplus does not last there, I rarely have one making the return trip in the trailer. If you would like to pick one up, it is best to order it in advance.

The second group is built less frequently. We weld Pietenpol mounts(4201-C) 2 or 3 times a year. We will occasionally build one extra to bring to Brodhead. We don’t generally have extras hanging on the wall. Most of the other mounts are one offs, and we build them at any time of the year because there is no economy of scale with them. If you would like one of these, I will be glad to make it, but for obvious reasons, custom mounts have to be paid for before we get started.

.

Above, a 2011 photo showing a large cross section of the mounts we make and bring to events. Scoob E examines the pile powder coated Motor Mounts that we produced. The front row is two KR-2 Mounts with a PA-15 Vagabond for Scott Statz’s project. Behind it is a Zenith 750 Mount that we delivered at a College, followed by a Flybaby mount for Bill Rotenberry. The last row is Russ Mintkenbaugh’s  PA-22-108 based Wagabond Mount, and the white one is for Bryon Stewart’s modified PC Cruiser.

.

If you would like to be assured of picking up a mount at an event, ordering it ahead of time from our website is the best way to go. Every now and then I will have a guy say “I ordered one from you months ago”, and he is referring to sending me an email with a name like “RV6Fyr” that said “I want a mount for my project, see you at Oshkosh” I think most people recognize that I can’t build an motor mount for a guy who I don’t have his name nor know what plane he is building.

.

If you have a special project or consideration, send me an email with your thoughts and please include a phone number and a good time to call you back in the evening. I will be glad to cover details on the phone at length. -ww