Kent's Long-EZ project

[Kent Ashton]

I have gone through four or five iterations of ideas to seal the nose gear box and electric nose lift.  A full cover over the NG30s and mechanism is probably the most airtight but the space between the top of the mechanism and the canard is so tight, I have not be able to figure out how to fab a full cover that would be easily removable.  Maybe heavy canvas would work but it'd be hard to fit-up on my existing airplane.  Here is today's attempt making strip-seals that the nose strut cover retracts against to seal the NG box.

I traced the curve of the bottom nose on some posterboard.  Then got 1/4" x 1/4" wood from the home store, steamed it and clamped it to to match the curve of the nose.  After the strips dried I cut them to fit the nose gear opening and attached some D-shaped insulating strips.(pic1)   The D-stuff seemed sufficiently squishy.  It is not very sticky but if needed, I will reattach it with contact cement later.  Then I made up about 5 springs from 3/32" welding wire.  I smeared epoxy on the wooden strips and lightly taped them at about the right place with a couple pieces of masking tapes.  Then I retracted the nose gear and inserted the springs to hold the wood pieces against the sides of the nose gear box.  (pics 2,3) I took a long stick and pushed the wood and D-strips down against the retracted nose gear and let them set up overnight.  Next day, I smeared a bit of micro to secure them better (not shown).

I had previously glued 1/2" heavy foam rubber in the big 1/2" space on either side of the NG pivot so I had a pretty good seal there.  Ahead of the pivot, on the bottom, I made a small flap of slilcone material and screwed it on the bottom ahead of the NG box.  The flap will open when the NGz extends and cover the hole when it retracts.

A fun day at the airport! 

[Kent Ashton]

Pitch Trim update:   I had to update my pitch trim wiring to make it possible to reverse a trim setting that reached a limit switch and disabled the trim.   Duh!   Added a couple of diodes.  About any size should work.  For reference, the PWM I used is shown here  https://www.canardzone.com/forums/topic/18661-kents-long-ez-project/?do=findComment&comment=63864

The Carling switch is a bit clunky but seems very robust.   Doing it again, I might use a MOM-OFF-MOM toggle switch mounted in the armrest near the stick.  There is not much need to adjust a trim on these airplanes once it is set so IMO, the switches do not need to be in the stick.  Here are a couple of ways to mount the screwdriver motor https://www.canardzone.com/forums/topic/18661-kents-long-ez-project/?do=findComment&comment=61194

My nose box seal (above) works pretty well when the NG is retracted.  It's a big noisy hole with the NG down. 

 

[Kent Ashton]

Here is a document called "Resource Guide for Non-builders of Canard Composite Aircraft" by Terry Yake.  It has lots of good info about EZs and maintaining them

 

LEZnon_builders.doc

[mquinn6]

   

[Kent Ashton]

I might be repeating myself but I had a thread on CanardAviation about modifying a prop and CA has disappeared so I will recreate it here:  I had a 3-blade Performance Prop (a 61.25"  x 76", 26.7 deg chord) that would not give me enough RPM.  I had been reading Paul Lipps about the importance of thin prop tips and after a fastener took a chunk out of it, I decided to cut the tips down.

I drew a line on the outboard 10" of the blades and cut the front part off evenly (pic 1, 2).  Rasped, filed and shaped the wood to a pleasing profile, checking the balance along the way.  In pic 3 I put used some lead shot to make that blade heavier.  I glassed it but that was mostly an anti-fod measure and to give me a warm fuzzy it would hang together.  Pic 3 is with glass on the other side and getting ready to glass the side showing.  The trailing edge wood has been removed to make a flox corner.  I also used JB Weld along the outboard leading edge and filed it to shape as leading edge protection.  The mod gave me about 125 more RPM in cruise and the only real change was making the tips narrower and a touch thinner.   It has held up well.  Interestingly, it is still a 61.25 x 76 prop.  For more details on glassing a prop, see my prop thread.  I did the glassing a little differently later.  Fun!

[Kent Ashton]

Saw this on the Cozy mail list:  Jochen Fuglsang photos of load-testing his Cozy III for the German authorities.  I suppose he passed  🙂

[Kent Ashton]

I always get a run or two in my paint job but I never developed a great way to sand them out.  One time I had a run so bad that I wiped off the wet paint with a lacquer thinner-soaked rag and started all over.  I usually don't screw up that bad but even a good paint job will have a run now and then.  I saw a great idea for sanding out runs on a site called Trev's Blog.  Here is his video    https://youtu.be/ySje2CcPZVA   but I can explain the idea here:  

Normally, when you try to sand out a run, the sandpaper or sanding tool sands into the good paint on either side of the run (#2) and exposes the primer so now you have to respray.  Trev's idea is to apply body filler over the run (#3) feathering out the edge of the body filler.   As you sand down the body-filler & run, the filler supports the sandpaper and keeps you from sanding through the good paint on either side of the run.  Gradually, you will expose the run (#4) and work the run and the body filler flat.  The body filler will get thinner and thinner until it becomes translucent and the run will become virtually flat.   He suggests starting with 320 grit and going finer grades.

I am looking forward to trying this on some old runs on the Cozy.  Let the paint harden up before trying this.  Trev is mostly into body metal work but he has some great tips.  He is a very entertaining fellow.

 

 

[jridge]

Interesting video (although he talks way too much and could get the point across much quicker).  Be interested to hear how your rework goes. 

[Kent Ashton]

I just mentioned it to my NASCAR-painting neighbor.  He knew all about it but he uses glazing compound

[Kent Ashton]

A couple of incidents I saw recently:  Pic 1, pilot began losing oil pressure and returned at idle for a safe landing from 25 miles out.  Note the puddle under the engine.  Cause unexplained so far. 

Pic 2:  N82V at Compton, CA.   I could not find much detail on this one but a person with some knowledge says "He set up for a short field approach with a very tight pattern due to the loss of altitude and to make sure he could make the field. The engine continued to run only at just above idle. On turning final, he was close in and off center to the right. He corrected left toward the runway, straightened out and bounced hard and came down on the dirt along the left of the runway where all hell broke loose. He ended up back on the runway in a ground loop."

Practice those engine-out approaches.  Pic 2 reminds me of the old caution "Get to the ground in control and you will probably survive the accident"

Also reminds me "Never give your airplane a cutsy name".  Old-timers know.

Edited December 29, 2020 by Kent Ashton

[Voidhawk9]

Well, both 'safely' on the ground.

No engine is ever perfectly reliable. So I agree, practice for their failure often - if you fly long enough, eventually it will happen to you. Might be tomorrow, might be 20 years from now.

[Kent Ashton]

Just reading this incident where a 70 year-old student pilot pranged her Cessna.  http://www.kathrynsreport.com/2021/01/abnormal-runway-contact-cessna-172r.html

What interests me is her narrative (pic 2):  "[In the flare and roundout] I looked down the runway as I had been taught.  And when the runway 'zoomed' in (as I had been taught), I started my flare, and held it . . . waiting for the aircraft to settle and I was on centerline.  Then in the next split moment, the nose wheel dropped down completely, hit the runway.  I recall that it came down hard"

It is clear to me this person did not have a sense of her height above the runway or a sense of sinking and likely dropped the aircraft in.  I have often heard instructors advise to "look down the runway in the roundout" but that's only half of it.   Of course, you have to keep the aircraft track aligned with the runway but a student can't rely on an automatic flare technique, i.e.,  approach at XX speed, reduce power at X, begin a roundout shifting your eyes down the runway and a good landing just happens.   I have never been conscious of a runway "zooming" in but a student must develop the ability to judge his height above the landing surface using his sense of height.  When I have had students that had trouble judging their round-out I would have them fly down the runway a few feet above it.  To do that successfully the student has to develop a sense of his height above the surface in his peripheral vision.  That sense is essential to avoiding a high or low roundout but what is it?  It is an awareness--in your peripheral vision-- of runway scale and the texture of the asphalt, grass, and runway markings. 

In the F-4 instructor course, we had to land from the back seat with very little forward vision.  On final we could check runway lineup by putting our helmet up against the canopy and looking through a pretty small hole above the instruments (pic 3).  That worked from several miles out until the roundout but at the start of the flare we were generally advised to sit up straight, stare at the back of the front seat, and rely on peripheral vision to keep the wings level and sense the runway height.

It is also important to feel "sink".  I have often flown with pilots who set themselves up nicely out on final.  They had the perfect final approach picture but they did not realize that they were sinking, i.e., they did not feel "sink" in the seat of their pants (actually, a very slight G reduction).  They allowed the airplane to sink below the glideslope.  I often found myself saying "Do you feel that sink?  Make a pitch correction"   Some of them said "I never felt that before but I see what you mean."  A worse case is when a student does not feel the sink developing that results in a dropped-in landing.

I suppose the G one feels on final is the cosine of the approach angle.  For 3 degrees it is .9989 G.  I doubt you can really feel the difference between 1 G and .9989 G but you CAN feel the difference in .9989 G and say, .95G which is what you might feel if the airplane is sinking on final.  Once you are conscious of sink (G), you will have better approaches. 

Again in the Phantom, we wanted to fly a steady ON-SPEED AOA tone on final.  Once in a while on a calm day you would get just the right speed, approach angle, and aimpoint that would result in a steady ON-SPEED tone.  Then, by holding the same power and keeping the same G in the seat of your pants, you could maintain that ON-SPEED most of the way to the roundout.  So satisfying!

I hope you found this discussion interesting.

[Voidhawk9]

6 hours ago, Kent Ashton said:

 ...To do that successfully the student has to develop a sense of his height above the surface in his peripheral vision. ...

Most people can learn this. Some take awhile to get it, a few never do. At least in my experience. Sort of an 'art' to it.

 

How did you find landing an F-4 from the back seat? I guess you wouldn't do it very often in practice, but how were your landings compared to the front seat position? Just out of interest!

[Marc Zeitlin]

12 hours ago, Kent Ashton said:

...  but they did not realize that they were sinking, i.e., they did not feel "sink" in the seat of their pants (actually, a very slight G reduction).  They allowed the airplane to sink below the glideslope.  I often found myself saying "Do you feel that sink?  Make a pitch correction"   Some of them said "I never felt that before but I see what you mean."  A worse case is when a student does not feel the sink developing that results in a dropped-in landing.

I suppose the G one feels on final is the cosine of the approach angle.  For 3 degrees it is .9989 G.  I doubt you can really feel the difference between 1 G and .9989 G but you CAN feel the difference in .9989 G and say, .95G which is what you might feel if the airplane is sinking on final.  Once you are conscious of sink (G), you will have better approaches. 

Actually, a constant descent rate is still at 1G - the only time there is acceleration or deceleration vertically is if the descent RATE is changing. That's the definition of acceleration. So no matter what the descent angle is - 1 degree, 3 degrees, 10 degrees - if the descent RATE is constant (300 fpm, 500 fpm, 1000 fpm), you're still at 1G.

Now, what MAY be going on in what you're feeling is a CHANGE of descent rate, and that's an acceleration, and that you CAN feel. But you can't feel velocity, and downward velocity does not imply a change of "G" loading. For this poor woman, what she probably didn't feel was the backside of the power curve increasing her descent RATE, and the wing stalling and slamming the nose gear into the ground.

[mquinn6]

As I read thru this - I just saw a little old lady that could not see over the panel and just a tuft of blue grey hair visible from the side windows...  (I am certain we have all driven our cars behind this view...).  Glad she is ok.

IF she was flying by the numbers (airspeed and decent rate (yes vsi has a lag time)) she should not have landed up like this.  This is (should) be all configured well before final and the "view" is the only thing that she should have worried about.    I suspect low airpeed causing geater decent rate - and exacerbated by pulling back on the yoke to "keep the view"...

Just an armchair quarterback - but I think about this every flight I take (and I am not NEARLY as old and grey (yet)....

 

 

[Kent Ashton]

9 hours ago, Marc Zeitlin said:

Actually, a constant descent rate is still at 1G

Ah yes, feeling reduced G due to acceleration.  Thanks, Marc

15 hours ago, Voidhawk9 said:

How did you find landing an F-4 from the back seat? I guess you wouldn't do it very often in practice, but how were your landings compared to the front seat position? Just out of interest!

It was not too bad if you got a good briefing on how to do it.  I never really had to land one for a student from the back seat.  Actually, for a guy moving from the T-37, my first impression was the rather poor front seat vision with a sight mechanism and RHAW scope in the way, and the pitch sensitivity flying formation.  Most pilots flew formation with their forearm braced lightly on their knee to avoid a PIO--at least initially.

[Kent Ashton]

Put some new pads on the Matcos and new tires.  I have a small hole in the wheel pants for airing up the tires.  Here's how I can align the hole with the valve stem.  Those tires are Desser retreads; really stout.  I think Marc has reported getting more landings out of them.  If I'm wrong, he will correct me.  🙂

[Marc Zeitlin]

10 hours ago, Kent Ashton said:

Those tires are Desser retreads; really stout.  I think Marc has reported getting more landings out of them.  If I'm wrong, he will correct me.  🙂

I love those things - I get 350 - 375 landings out of a set - way more than the new tires, that cost more.

They are not always available, though...

Edited January 21, 2021 by Marc Zeitlin

[Kent Ashton]

Saw these pics of Wayne Blackler's EZ.  (pic 1) a nice way to seal up the nose strut.  I presume the black thingy hinges down as the strut extends.  Perhaps it is pulled up by a small spring when the strut is retracted.   (pic 2) His downdraft intakes look nice but I thought he had abandoned them.  Guess not. 

Speaking of intakes, you might find this intersting:   On my EZ, I built top scoops based on Blacker's photos they but did not work for squat (pic 3) ---the engine would overheat before I could get to pattern altitude.  I remade them into forward-facing intakes (pic 4).  Even then the forward-facing intakes did not cool as well as a plans NACA in a climb.  I turned out I just didn't have sufficient exits for the cooling air.  After I built some exits on the bottom cowl (pic 5) just below the cylinders and all my cooling problems went away, in fact, my forward-facting intakes could probably have been made smaller.  

So I would speculate that these sort of NACA-style downdraft intakes would work OK with good exits

[Kent Ashton]

Seen on FB:  Lost left brake; owner speculates it was a Nylaflow failure.  I still have Nylaflow on my Cozy but I am very careful about it.  I changed it out at the 8-year point as a precaution and it was still very flexible and serviceable.    OTOH, I had a roll of it i bought from a surplus place and it had gotten stiff.  It would snap with just a little bending!   I think I will keep using it and just change it out every 8-10 years--not hard to do--just link the new to the old with a piece of thin rod and push it through.  If I was buying a strange airplane, that'd be something I'd change right away.  Based on the owner's narrative, his Nylalfow might have been 28 years old.

[Kent Ashton]

Welcome to "Brake Week" at Kent's Long-ez project!:  This sad Varieze owner said

Quote

I had plenty of airspeed but it wouldn't rotate. I taxied back to the end of the runway and tried it again with the trim all the way back. Still wouldn't rotate.. I tried it a third time with the same result but when I pulled off the runway the brake was so hot the whole wheel caught on fire.

IMO brakes on our airplanes are good for about one high-speed abort.  Matcos use a thicker rotor that can absorb a little more heat so maybe they can do more.  This chap had Clevelands on his Vari and what looks like a thin 1/4"-thick rotor.  Then I will guess he was using the usual red (flammable) brake fluid.  Nylaflow tubing?  No.  There appears to be a stainless steel or aluminum tube going to the caliper.  If I did a high speed abort I would probably get out and check the brakes.   BTW I have changed all my o-rings to EPDM and use DOT 3/4 non-flammable brake fluid.

What caused the failure to rotate?  Undetermined at this point but from experience, most aircraft WILL rotate given free controls and enough airspeed.  I took off solo one time in the Cozy with my usual 40# of ballast in the nose AND my 25# lead weight hanging in the nose gear.  That got my attention but it flew.  I believe more wrecks have been caused by high speed aborts than failures to rotate.  There is not much time to decide but my default mode is GO unless I felt a loud bang or some other clear indication that a high-speed abort would be the best course of action.

I get the impression the owner did not build this Vari.  There are a lot of things to know about these airplanes, like the history of their brakes.  Fortunately, I was able to muddle through my first experience with my store-bought Cozy III without hurting myself but there was a lot I did not know.  With these airplanes being sold-on to younger owners, this is a tough way to learn.

Edited January 24, 2021 by Kent Ashton

[Voidhawk9]

Never a happy day to have your aircraft damaged.

 

I think if I ever found my aircraft would not rotate, I'd abort right back to the ramp and figure that out, not go back and try to force it into the air! Something is wrong, and the airplane is talking to you!

[Kent Ashton]

Just talking to a gent about some foam.  Pic 1 is the foam he got recently from Spruce.  Pics 2, 3 are the sort of foam I am used to seeing.  His foam is very coarse with big bubbles.  I suppose it will be OK as a shape to hold the fiberglass but I think it will require a lot more micro to fill the voids in the surface.  The extra micro is not a lot of extra weight but I am just remembering that it probably takes me 3 or more butter-containers (32 oz each) of micro to micro a wing surface before applying the glass and it might take 5 with that sort of foam.  Pic 3 is scrap left over from hot-wiring.   I have seen blocks of Dow foam at an insulation dealer.  They all appeared more like pic 2.  I think Spruce got some bad batches.

[Kent Ashton]

I saw a pic of a guy trying to level his wings to his fuselage with a water level.  One time I tried to level the floors in my Dad's old house with a long water level using a garden hose attached to clear tubing.  It was really squirrely.  Later I read that if you get a few bubbles in the water, the level will be different.  Duh!  It may work OK if you are careful to tap out any bubbles.

I managed to do OK with tight nylon string and an ordinary brickmason's level.  A swiveling laser level would be nice.   I thought about making one with a laser flashlight hot-glued to a flat plate.  Show me your pics!   🙂

BTW, the chap above contacted Rob Irwin at Spruce who said he would replace the foam if the builder "couldn't make it work".   Weak sauce but it helps.

Edited January 28, 2021 by Kent Ashton

[mquinn6]

I use the autoleveling laser.  can set it above (or below to have less eye contact) and measure up with a story pole.  can set it right up on the firewall or nose as it does a 360 projection (for those with tight hangers).