Kent's Long-EZ project

[Kent Ashton]

It's probably me, but I've looked at these pics several times and I don't "see it".  

Sure you can Jon. See how the left winglet points about 3ft left of the center of the airport gate and the right one points 8-10 right of center? I just lined the airplane up on the gate by eye but i'm sure the winglets are at different incidences.

[Jon Matcho]

Yes, but look at where the winglets meet the end of the main wings -- they're "off" by the same amounts.  Unless you have perfect "gun sights" lined up with the gate, I wouldn't have confidence in this particular test.  

 

How are you going to figure out the exact measurements anyway?  I thought this was done by measuring to the nose?

 

Just my opinion and curious... maybe I still don't get it.  

[Kent Ashton]

How are you going to figure out the exact measurements anyway?  I thought this was done by measuring to the nose?

 

The winglets are set by measuring off of the inboard aileron cut-out (pic).  I don't think the winglet angle (dihedral?) is very critical but the incidence surely is.  Even in my Cozy, I had to but a small block in the rudder to displace it and take out a little yaw.

 

If I install a new winglet, I'll make a jig that fits over the winglet about 1/4 of the way above the wing with an offset centerline and compare the chord line of the two winglets in relation to the nose in the same way that the wings and canard are set.

[Jon Matcho]

That's a lot of work, so I hope (not really) your yaw is worth fixing.  Nothing you can't trim away?  I've seen blocks/stops in the rudder before...

 

Maybe when you measure it will turn out to be a very small difference, meaning the real reason for the yaw will be hidden elsewhere.  Just thinking out loud...

[Kent Ashton]

Winglet misalignment:  Studying page 19-10 in the plans again, it appears the winglet chords are designed to be parallel with the A/C centerline at the 157" body line.  Gee Burt, why didn't you just say that?!

 

So I made some careful measurements against the hangar wall using a jig on the winglets to tell where the winglet chord line is pointing.  Picture below.  My left winglet points .44 degree inside the ideal zero angle and the right winglet points 1.8 deg outside the zero angle.  This confirms with what I was seeing in my fence photos earlier.  Good thing I checked because I was anticipating resetting the left winglet.  Will do the right one instead, and try to set it at .44 deg in to match the other.

 

BTW, I drew out the Long-ez planform using the plans FS/BL positions in a CAD program.  It was interesting to see that the aileron-to-winglet-leading edge distance measured by my CAD program is 102.084" vs the plans 102.15" and the aileron-to-winglet-trailing-edge measures 108.102" on the CAD vs the plans 108.35", so the CAD result matches the plans are pretty closely, I'd say.

 

Still, I like the jig idea and think it's a better way to align the winglet chord.  It is pretty easy to tell something isn't right.

 

 

 

Scan.pdf

[787Guy]

How did you extend the chordline onto the hangar wall ? Did you just use a string or a laser ?

[Kent Ashton]

How did you extend the chordline onto the hangar wall ? Did you just use a string or a laser ?

Tight nylon string with a wife on the other end.  A laser would be nice but thin nylon string is pretty accurate. 

[Jon Matcho]

It was interesting to see that the aileron-to-winglet-leading edge distance measured by my CAD program is 102.084" vs the plans 102.15" and the aileron-to-winglet-trailing-edge measures 108.102" on the CAD vs the plans 108.35", so the CAD result matches the plans are pretty closely, I'd say.

Yes, very close.  Glad to see you've got this under control (not that you otherwise didn't)!  

[Kent Ashton]

Starting winglet surgery.  Pic #1 is the jig to check the winglet incidence.  Flip it over and it works on both wings.

 

It took about a hour to get the winglet off with a Sawzall; most of that just pondering how to do it.  It goes pretty fast except for finding and chipping around the rudder conduit.  If I save the conduit, I might not have to order another swaged wire.  The winglet antenna is cut off; it's pretty easy to run a new coax through the wing for the new antenna in the new winglet.  Next: sanding off old layers

[Jon Matcho]

No turning back now!  Looks good Kent... I would have been anxious around the wires.  Happy sanding...

[Kent Ashton]

I am posting this in the hope that non-builders won't be afraid of working on their airplanes.  Almost everything on an EZ/Cozy can be fixed or modified, even down to building a new wing.  Just cut the bad stuff off and start rebuilding.  :-)

 

In pic 1, I used a belt sander and 36-grit to gently remove the filler and expose the 7 UNI layers that bond the winglet and wing.  I marked them with a black Sharpie.  Under the UNI are two layers of BID that also bond the winglet to wing and underneath that, the basic wing layups (top: 2 layers of UNI on crossing angles and one UNI lengthwise; bottom: two layers of UNI on an angle).

 

Sand, vacuum, inspect, repeat.  It was easier than I had expected.  I stopped when I was just getting into the BID weave.  I didn't want to sand into the wing layups.  The plans call for the BID layers to go 15" up the wing.  I didn't sand that far--only 12-13 inches to get the UNI off.  I plan to add one layer of BID and the 7 UNI layers.  It will be a tad heavier than original but not appreciably so.

 

Next: fitting the new winglet

[James Bailey]

Kent,

 

I am so glad that you posted this...what timing

I am going to start the repair on the scrapped up nose on the varieze I bought where the previous owner forgot to lower the landing gear...

my question is how hard was it to identify each layer/layup as you sanded the area down ? any tips or tricks you would recommend

 

thank you sir

James

[Kent Ashton]

Ha! Unfortunately, i had to do that myself once, James.

 

It should be an EZ job. You just need to sand off filler so you can overlap the new glass over the old glass. It is not very critical how you expose the old glass.

 

As i recall, i micro'd on a piece of new foam and sanded it to "a pleasing shape" and glassed it. Really not much more complicated than that although you may want to use some kevlar for next time. :-). Maybe use a little extra glass under the rubber puck for a little reinforcement there. It just takes a lot of little steps to get back to a clean, painted finish.

[James Bailey]

Can I use the west epoxy system or do I need to utilize something else?

[Kent Ashton]

West is fine for repairs like that.  I think people have built airplanes with West but most just use it for filling.  The West Microlight filler is easy to sand but expensive.  You can use regular micro balloons if you have those.

[Kent Ashton]

Aligning the new winglet:   Spent a few pleasant hours at the airport setting up the airplane and aligning the new winglet (pics).

 

Then went back today and did it all again because I realized I hadn't accounted for variation in winglet chord position in relation to aircraft centerline.  Of course, in theory the winglet chords should be parallel to, and the same distance from the aircraft centerline.  Mine are not by about (gulp) 2.5 inches!  I don't know how that number got so huge but it had to be accounted-for when aligning the winglet.  I could not simple aim the new winglet chord the same distance from centerline as the other winglet.  After re-marking the winglet position, it did make a very slight difference (about 1/8" at the wing trailing edge) in how the winglet is positioned.

 

Of course, my positioning of the centerline could be off but 2.5 inches is pretty obvious.  I am using the nose and the prop flange to establish centerline and it looks pretty good.

 

Pic one is the jig and string projecting the chord line to the hangar wall (with a 5" offset).  It is very repeatable.

 

Pic two is a rig to hold the winglet and set the cant.  I do not know off-hand if the winglets should have an inward tilt but my left one does, so I'll try to match it.

 

 

[Jon Matcho]

That was fast!  Where'd that new winglet come from?

[Kent Ashton]

That was fast!  Where'd that new winglet come from?

The Winglet Fairy. :-)

 

It only takes a couple days to build one but cutting out the rudder and attaching it is a bunch of steps.

[Kent Ashton]

Had a bit of a setback when I went to the basement planning to some winglet layups and found the sewer system had overflowed.  Don't know how or when but S--t was everywhere. Thank goodness for shop vacs.  A good mop-up with bleach has almost killed the smell.

 

Anyway, I had the inside winglet layups done and as soon as I can return everything to its place, will get the bottom-outside UNI layups done.

[Jon Matcho]

Ugh, that must have been awful!  Vinegar spray is good when the bleach smell gets too much. As they say, "sh*t" happens.

 

I can also see now why you have little problem making parts with that mill and other machines in the background. 

 

The winglet is looking good!

[Kent Ashton]

Back at it after a bit of basement repairs.  You could build an EZ in a year if life didn't get in the way.

 

Pics: winglet ready for outside BID & UNI layups; layups done.   4th pic is a suggestion for working with UNI which can become a stringy mess. Run a strip of masking tape, cut down the center of the tape.  After wetout, it is pretty easy to trim off the tape without making a lot of loose strands.  It ain't rocket science but it helps.

[Kent Ashton]

Winglet almost ready for primer.  I would like to put this winglet out in the hot sun in primer to get a little post-cure but it's not hot enough to do that this time of year.

 

See the pits and pinholes?  Two wipes of epoxy almost killed them all.  First wipe used a little West filler--a thin-soup consistency, second wipe was straight epoxy.  Actually, a third and forth wipe with straight epoxy or a runny epoxy/West filler mix would have helped but I get impatient and will probably finish-up with a primer-surfacer.  I learned of this epoxy-wipe method from seeing Cory Bird's beautiful airplane at Oshkosh one year.  He used five or more epoxy wipes allowing it to tack-up between wipes, until all the defects are filled, then it can be wet-sanded with 320-grit and primed.

more here:  http://forum.canardaviation.com/showthread.php?t=1514

 

I have tried various ways to prep the sanded surface and kill pinholes:

 

- Nat Puffer recommended spraying epoxy primer thickened with micro--no great results there.  You cannot spray enough of it to fill 36 grit sanding scratches and it does not kill pinholes.

- Conventional primer-surfacer will not kill pinholes.

- I have used the old waterborne Smoothprime which worked pretty well to kill pinholes but others have cursed that it does not adhere well.

- The Cory Bird method seems to get the best results but use 3 or 4 wipes and don't leave any hard ridges of epoxy.

- I have tried wiping-on conventional primer-surfacer but it dries too fast.

- When I only have a few pinholes, I will dip a toothpick in primer and touch each of them.

- Nowadays, when I think I'm about ready for actual primer, I usually spray a thin coat of cheap black sandable primer from a rattle can and sand it all off to expose defects.

 

My airplanes are not show planes but they look decent.

 

Pump your septic tank every 3-5 years or die!

[Kent Ashton]

Here's a variation on the Davenport pitch trim idea.  It uses spring wires vs. a fiberglass spring.  Use 1/8" wires for a Cozy, 3/32" for an EZ.  I have it actuated by an electric screwdriver in the EZ but in the Cozy, I am using a knob on the instrument panel.  I like the feel of it and pitch trim can be adjusted precisely.

 

Description: Use a short piece of 4130 tube that will fit over the elevator torque tube.  Weld on a tab to capture the two wires with a screw and nut.  Rivet it to the elevator torque tube so that it doesn't hit the canard T.E. at full up-elevator.  For the adjustment mechanism, weld three hardware store long nuts to make a thread follower and drill two holes so the wires can be captured in the long-nuts with screws.  The spring wires are pulled forward in use so you will need a suitable mount at the FU-22 station to pull against and the mount must allow the threaded rod to rotate to vary the pull on the spring wires.  You may need a universal joint; mine is a cheap 1/4" universal from a socket set. 

 

The 4th pic shows a first iteration mounting system on the torque tube that was more complicated.  Wouldn't use that.  I also found the small crank handle in the last pic did not work and made a simple knob I could twist.

 

To remove the canard, you loosen the two screws holding the wires and put the wires out.

[Kent Ashton]

Seeing an abandoned, heavy-looking Cozy/Aerocanard project on Ebay prompts me to reflect on building light.

 

In another life, I flew F-4s.  Mostly we flew them with two 370 gallon external fuel tanks but often in the winter we would add an additional 600 gallon centerline tank.  The total, including the internal fuel was 21,000 lbs of fuel, equal to 70% of the weight of the empty airplane! (30,000#)  You get used to flying the airplane in those configurations and don't think too much about it.  A few times a year though, we would take the tanks off and do some training in the clean airplanes.  What a joy to fly a light airplane!  You would leap off the runway.  The airplane felt like a sports car.  "Oh Boy", the guys in the squadron would say, "We're gonna fly some clean airplanes this week!"

 

For us, in an 1180# empty-weight Cozy with 50 gallons of fuel, you, one pax, and 120 lbs of luggage and tool kit, you are carrying a load equal to about 71% of the empty weight.  That is significant, and we don't have afterburners.  :-)  Taking off on a hot day, fully loaded, a cruise prop, perhaps with a crosswind that does not help you and even makes you tap the brakes, and trees at the departure end, it will get your attention.  It has made me pucker a few times.  Need to climb on top?  It's not happening very fast.

 

Sometimes I go somewhere close-by and takeoff solo with only 8-10 gallons.  The Cozy is a delight to fly in that condition and takes me back to my former life.

 

Build light.

[Kent Ashton]

My winglet is back on the airplane.  No pics, it is just a winglet.  Have not had a chance to test it yet.

 

A friend called me recently about a 1985 Glasair he was looking to buy.  Fresh paint, low hours, low price, nice looking airplane.  The engine (pic) had 70 hours since an '83 overhaul and was installed in '85.   Seven-zero hours!  The engine looked pristine and the owner pitched it as an overhauled low-time engine, which it was, but it had never been pickled.  Moreover, the owner had started it up every six months and run it for a half hour and changed the oil every year.  See pic from the log book

 

Of course, that engine is probably junk--full of rust.  This is the worst thing you can do to these engines.  I discussed with a local AI who agreed it'd likely need a full overhaul.  

 

Moreover, from the the log book, this was originally an "overhauled as necessary" engine and there was no indication about the life of the engine before overhaul. The overhauler replaced exhaust guides, exhaust valves, rings and gaskets.  Yes, that's an overhaul but just barely.  What a pig-in-a-poke!

 

A Cozy sold recently with the same sort of engine condition--early Cozy IV nicely done but with 120 hours or so--engine apparently never preserved per Lycoming.  Some partners bought that airplane last year, flew it for a few weeks and threw a rod.  I mentioned it to my friendly AI who said main bearings get corroded, seize-up and that's what happens.   I have had my own adventures with rust.

http://forum.canardaviation.com/showpost.php?p=69231&postcount=40

 

Lycomings are reliable engines but don't let them sit without taking precautions.  You can't be too anal about keeping fresh oil in them and preserving them.