Kent's Long-EZ project

[Kent Ashton]

 A post about long-noses on EZs.  I just want to cross-reference it in this thread  https://www.canardzone.com/forums/topic/32714-hangar-electricity-and-other-rants/?do=findComment&comment=63634

 

[Kent Ashton]

This is a little aileron trim idea from the LEZ project.  I use a similar idea on the Cozy.  It's a bit fiddly to install but very precise to adjust.  Uses 3/32" spring wire (music wire) captured by a fitting on the control rod with a welded-up screw device that moves the trim spring up and down.  BTW, if you are building an EZ, use the Cozy stick weldment shown in pic 2.  It has advantages over the original EZ stick although you might have move the control rod inboard just a tad.

Also, homemade CHT bayonets.  I probably posted that before but a good hack is worth repeating.  Hardware store 3/8"-24 flare fitting, type J thermocouple wire, small spring.  Coil up the wire and silver-solder it into a ball.

Edited June 23, 2019 by Kent Ashton

[Kent Ashton]

Weeding out some old pics on my computer.  Here are two ideas that didn't work:  First, NACA-style cooling intakes.  I think they are naturally inefficient and subject to any backpressure inside the cowl.  The air is just as happy to skip over the intake.  Later I modified them to a forward-facing scoops   The next idea was that downdraft cooling air would exit mainly around the large exhaust openings.  Nope.  There was probably a lot wrong with this design: intakes that didn't want to intake, too many corners and obstructions between the bottom of the cylinders and the exit openings, and exit area rather small.  Another bad idea was the oil-service door that did not hinge at the forward edge.

Pic 3, 4: Making some strut fairings.  I used the two small templates in pic 3 to cut a foam "airfoil" and sliced it and micro'd it to the strut.

Pics 5, 6: Oil flow test of the cowl and later intake -  I the pattern behind the cowl was about what you'd expect.  This is why I do not think the standard cowl opening on a EZ is a very good spot; it is area of turbulent, disorganized air--not the low pressure area you might imagine.  Note the puddle in front of the intake.   I would like to see a smoke test of that area in one of NASCAR's wind tunnels.  It would probably give the NASCAR aero guys a good laugh!

Edited June 23, 2019 by Kent Ashton

[Voidhawk9]

NACAs are great for things where sometimes you want the air to skip over the top, like for an air vent that may be closed sometimes. Not so great for pressure recovery - as stated in the original paper describing the inlet. North American tried to use huge NACA scoops to feed a jet engine (YF-93), which did not work very well, and after tweaking the NACAs a lot, just replaced them with ram scoops. Some guys have made them work, and obviously a lot of canards use them, but they do seem very sensitive to details to cool properly.

 

Not sure how much the rounded cowl vs open cooling outlet have in common for airflow there. Though, I'd expect that the cooling air -having been twisted through at least 180deg and forced around the engine- doesn't have a lot of energy relative to the free-stream and so will stagnate and burble around readily. Having the outlet not too close to the prop seems to help too, perhaps the pressure wave or the blocking presence of the prop blocks the cooling flow somewhat. People have reported improved cooling once they cut the cowl back a bit. Apparently the prop does not suck the air out here - that section at the root of the prop is thick and relatively inefficient anyway.

 

Still lots of potential for improvement in canard aft ends, IMHO. Exactly what that looks like is another question!

[Kent Ashton]

Update on the ADSB:  Yup, my EchoUAT Baro failure went away when I changed the Garmin 327 RS-232 output setting to "remote" _AND_ moved the cursor off that field so the Garmin would store the change.  (The Garmin is hardwired to the EchoUAT)  However, the next FAA Performance Report showed failure of "Flight Plan ID"!   This was not a previous failure.   Uavionix' instructions say to leave this field blank.  I have posted a question with Uavoinix that will take "3 to 5 days" to get answered.  This is poor customer service.  They could help us out a lot with some same-day responses and by posting some simple troubleshooting FAQ.

This guide to the Performance Report was useful.  https://adsbperformance.faa.gov/paprusersguide.pdf

I have about four hours on the new prop and have run it at WOT at 3000' MSL.  Still has two blades attached.  :-)

[Kent Ashton]

Further on the ADSB:  "Apparently" to hardwire the Uavionix EchoUAT to a Garmin 327, you need a special MUX (multiplex) cable that resolves differences in baud rates between the Echo, the transponder, and maybe the altitude encoder.   Neither the EchoUAT install manual nor the product webpage tell you that.   The tech who said he would call me back to discuss my configuration has not done so after 24 hours so I called their order department to get a cable.  The clerk was a little hazy about which MUX cable I needed but I hope to see one in the mail.  It looks like this thing is going to work, even if I have to use the "sniffer" ("TRANSPONDER MONITOR") mode but I see others have similar complaints.  Not sure I would buy this unit again.  https://www.myrv14.com/N14YT/The_Box/index.html 

FWW, it seems that when I got a good Baro report and good Flight ID report, I had been in "sniffer" ("TRANSPONDER MONITOR")  mode.  However, when I tried to input the Garmin transponder data via the hardwire in "EFIS/PANEL" mode, the baro worked but the Flight ID failed, thus the need for the MUX cable.  BTW, the tech confirmed that the "FLIGHT ID" should be left blank at all times as stated in the manual.  See what I mean?  You aren't using it but it still fails?  :-(

Which reminds me of another thing:  Poking around the airplane I heard a very faint squeal coming from my Artex 345 ELT.  The battery is good to 2023.  It was not an ELT signal.  No changes to wiring or switches.  Squeal stopped when I disconnected the D-Sub.  It took several days again to get a response from Artex and no explanation for the squeal  but maybe I have a replacement unit coming.

Airplanes do not make your life less complicated.  And I do not like the ADSB.  98% of the targets are no factor.  They divert your attention into the cockpit and the buzzards do not use ADSB.

[Kent Ashton]

So the Uavionix tech just called me back and we established that because my existing encoder, a Trans-Cal 120-(XX)A, uses a 10-wire gray code output to the Garmin 327 transponder, Uavionix'  MUX (multiplex) cable will not work and I will have to rely on the sniffer mode or get a new encoder (or dive into the MyRV14 box above).  A newer encoder would use RS-232 output which would work with their cable.    To correct what I said two posts above, I got good baro altitude in that report because I was likely in sniffer mode and the cable issue did not come into play.   (I still need to check the Flight ID issue.)

To be clear, when the Echo is hardwired to the transponder it needs a squawk from the transponder and an altitude from the encoder.  In sniffer mode it receives both over the airwaves.  

 

Edited June 27, 2019 by Kent Ashton

[Kent Ashton]

A project more dangerous than building your own airplane:  I saw a recumbent bike like this on Craigslist (pic 1).  Whoa, that thing was twitchy!  I modified it thinking it would be easier to ride (pic 2) but it was still a bear to control and at my age I can't afford the contusions to get good on it.  Sometimes you get the bear, sometimes the bear gets you.  Back to Craiglist!

[Barry]

That thing looks whacky....

[Kent Ashton]

7 hours ago, Barry said:

That thing looks whacky....

That's what they said to Burt.  :-)

Grabbed this shot (pic 1) off a FB page.  It seems to me that a small map at the distance shown here is going to be hard to read and adjust.  I put my Ipad Mini right in my face and it is about right. (pics 2, 3)--just the right viewing distance and the angle is good for minimizing glare.   Another problem with touch-screens is using them in turbulence.  There are many times flying around down low that it's hard for me to hit just the right spot on the Foreflight to select some bit of data when the plane is bumping around.  I suspect it's going to be even harder at arms length on a small map display.  I like the portable maps/ipads but they need to be brought closer to the face and the ipad needs a pretty sharp angle to avoid glare.  It would be good to have some sort of steadyrest for the hand that you can rest your palm against when tapping the map.  Hmmmm ...   Perhaps a Ram mount or fold-out on the side.

I am mod'ing this ipad mini holder so it holds the correct angle for me in the right seat but I can swing it away (forward) for takeoff and landing and it stays in that position.  Right now it flops around a little.

[Kent Ashton]

If somebody has original copies of Long-ez drawings, plz download my drawing of the F22 bulkhead, print it out and and see how it compares to the original or if you contact me directly I will get one printed and send it to you for a check.  It's in dxf file but I can put it in other formats.  I tried to take the A3 Open-ez drawing, put it in the proper scale and draw over it.    Should be well within tolerance to build from.

F22.dxf

[Voidhawk9]

6 hours ago, Kent Ashton said:

I am mod'ing this ipad mini holder so it holds the correct angle for me in the right seat but I can swing it away (forward) for takeoff and landing and it stays in that position.  Right now it flops around a little.

How about a folding tray table for your passenger's meals? 😉

[Jon Matcho]

21 hours ago, Kent Ashton said:

If somebody has original copies of Long-ez drawings, plz download my drawing of the F22 bulkhead, print it out and and see how it compares to the original or if you contact me directly I will get one printed and send it to you for a check.  It's in dxf file but I can put it in other formats.  I tried to take the A3 Open-ez drawing, put it in the proper scale and draw over it.    Should be well within tolerance to build from.

I can cross-check your drawing against the originals used for the Open-EZ package.  I'll print and compare and report back.  I'll also use this as an opportunity to finish Open-EZ Revision 7!

[Kent Ashton]

 Brazilian Bumerangues:  I have not seen this sort of intake used in real life before (the stubby wing thingy on the aft end of the fuselage, pics 1, 2) but something similar is pictured in Dr. Hoerner's book on drag.   I see that they have at least two versions.  The airfoil version appears less draggy to me than the version in pic 3.  It'd be interesting to compare it to the drag of a wheel pant.  The airfoil is smaller and finer-tapered but of course the open inlet will be draggy compared to the nose of a pant.   Funny looking but it gets the intake out of the boundary layer and doesn't result in a blunt, draggy rear.

[Kent Ashton]

I copied these pics off a VansAirForce discussion about metal found in the oil filter (Hat tip: Dan Horton).  I have not thought about "shared cam lobes" before but it's pretty obvious that some are shared by just looking at the top of the engine.  Sure enough, the O-360 parts manual shows 5 cam lobes for a 4 cylinder engine.  It makes sense that those would show the most spalling.

It would be nice to know how my 700 hour engine is doing.  When I rebuilt an O-320 with about 1800 hours, the spalling was not as bad as shown here but I still had to replace most of the lifters and the cam.  Very expensive part, that cam.

Edited July 3, 2019 by Kent Ashton

[Kent Ashton]

Got a good ADSB Performance Report today with the Uavionix EchoUAT in the "transponder monitor" (sniffer) mode.  To summarize, it does not work to hardwire the Echo to a Garmin 327 transponder unless you are using a _serial_encoder feeding baro altitude to the transponder.  My older Trans-Cal 120 was a gray code encoder.  Finally!

[mquinn6]

Way to make it work!  Congrats!

 

 

[Kent Ashton]

This is the mod I came up to keep the ipad holder from flopping around.  The notches keep the holder in viewing position (for a right seat pilot) or angled straight ahead for takeoff and landing.  I can be raised slightly and swiveled for the pax to look at.  Doing it again, I would probably machine a little aluminum block with notches but it was easier to mod what I had before.  3rd pic shows the underside of the armrest.  I could have embedded a piece of phenolic in the armrest at the building stage.  See pics above for the holder.

[Jon Matcho]

On 6/20/2019 at 7:22 AM, Kent Ashton said:

A post about long-noses on EZs.  I just want to cross-reference it in this thread  https://www.canardzone.com/forums/topic/32714-hangar-electricity-and-other-rants/?do=findComment&comment=63634

In a nutshell, the best nose shape for an aircraft that flies subsonic is a parabola (raindrop shape).  The best shape for a supersonic aircraft is a pointy nose.  By 'best', I mean the shape the has the least amount of drag.

As mentioned in that post, the builder/flyer, and Marc Zeitlin, while the look of a pointy nose may appeal to some they certainly do not help aerodynamics and can actually destabilize the aircraft.

My nose will be as close to a clean parabola that I can shape.  Achieving that will be "sexy" to me (I know, I don't get out much).

 

[Kent Ashton]

CIRCLING APPROACHES/LOW PATTERNS:  Ya know, many pilots have died doing circling approaches or trying to fly a visual traffic pattern below a low cloud deck.  The reason is that pilots rely on a "look angle" to the runway to set up their downwind position but the same look angle at 500' AGL is much closer to the runway than for a 1000" AGL pattern (pic).   So they establish the same look angle and end up with a very tight base turn to the runway and sometimes even slow down to make the turn radius smaller.  Result: stall-spin or overshoot and go-around.

Also, when the visibility is bad, as it often is when the ceiling is low, a pilot can be fearful of losing sight of the runway and is hesitant to widen his downwind enough (i.e., shallow-out his look angle) to use a normal base turn bank-angle.  And who knows what towers and obstacles lurk out there on a low downwind?  Psychologically, we do not like to fly off away from a runway in the haze and murk.

Also, a pilot will need to start the base turn as a level turn using more power.  That's different.  And the base position will also look shallower.  If a pilot begins a base turn descent as he would on a normal pattern, the trees can reach up and grab him.

If these factors are not in your mind as you fly a circling or low-deck approach, you will often screw it up or scare yourself.  As an instructor in Tweets, we could count on a student screwing up his first for-real circling approach; what fun!    Go out and practice a couple, the next time you fly.

It's good to get in the habit of establishing a downwind position by knowing the runway length (say, 5000') and visually putting yourself a runway-length (or whatever you use) offset from the runway.  On a 2500' runway, the perspective from downwind is quite different but by using 2 runway lengths as an offset, you'll be in your normal downwind position.

[Kent Ashton]

There is a lot of talk about the FAA's recent requirement to log an ADSB Service Availability Prediction Tool (SAPT) preflight check or be accused of not exercising "due [preflight] dilligence".  

https://sapt.faa.gov/res/SAPT_User_Guide_v4.1.pdf

The regulation is obtuse but but what I get out of it is that if you have an ADSB employing a WAAS GPS source, you merely have to check the usual NOTAMS.  The clearest thing I could find on this is the ICAO instruction

See  https://www.icao.int/SAM/Documents/2017-ADSB/08%20FAA%20Briefing%20ADS_B%20Rules%20and%20Airspace%20(2).pdf

Quote

[at p. 14]  • There are three common position sources in use for ADS-B:
• GPS that behave as if Selective Availability (SA) is still active (SA-On);
• GPS that behave as if SA has been deactivated (SA-Aware), and
• GPS that have Satellite Based Augmentation System (SBAS) such as the U.S. Wide-Area Augmentation System (WAAS)

Selective Availablity is the jitter built into the GPS system by the military which has since been turned off but apparently there are older GPS receivers designed to deal with it.  Note also that WAAS is an SBAS.  ICAO also says

Quote

[at p. 18}   • Operators with SBAS systems need only check NOTAMS

Also see the bottom of the chart on page 7-35 in the first reference which says "SBAS - no preflight availability prediction required"

I installed a cheap Uvionix EchoUAT and SkyFYX (WAAS) antenna so the check does not seem to apply.

Edited July 16, 2019 by Kent Ashton

[Kent Ashton]

I was just talking to a buddy about where and how to mount a fuel pressure sender on a Lycoming.  I like to measure the pressure on the outlet side of the engine-driven fuel pump because that's what the carb/Ellison sees.  On my Cozy, I drilled and tapped the steel Lycoming fuel pump fitting for a steel AN816-3  (AN3 flare to 1/8" NPT pipe) fitting (pic 1).  However, I see now that Spruce sells a tapped fitting that would make it easier.  https://www.aircraftspruce.com/catalog/eppages/lycomingfitting00783.php  Below is an RV builder that used the fitting. (pic 2)

From the FP fitting I use a fuel hose about one foot long running to a similar AN816-3 fitting, an AN910 1/8" NPT to 1/8" NPT coupling with the sender screwed on the coupling.  The sender is mounted on an engine mount tube with a large and a small Adel clamp.  It is self-aligning with the hose.  The sender could also be mounted other places.  

If you are new to fittings these are called "Lycoming/AC fuel pump fittings".  They are listed with fuel pumps and not in the AN fitting section of the Spruce catalog.  

[Kent Ashton]

I simplified my pitch trim control a bit, using a cheap ($6-$8) reversing PWM from Ebay similar to pic 2.   I hot-glued it to a piece of non-conductive fiberglass and mounted it in the armrest with a couple of screws.  I had to go from a 2A fuse to a 5A but otherwise, it works the same and simplified the wiring a little.  Throw the cheap switch away and use the nice Carling switch.

[Kent Ashton]

Something new to me: "Magnehelic" gauges for measuring cylinder Delta-P (cooling differential)   http://www.dwyer-inst.com/Product/Pressure/DifferentialPressure/Gages/Series2000    At about $63 they are not too expensive.  I have used the old water-manometer method for measuring cylinder Delta-P and an airspeed indicator for measuring flow into a NACA scoop.  The manometer is a bit bulky and the ASI quit after snapping from 0 to 150 knots for a few minutes.

I saw that 8.5" of differential was suggested in a Van'sAirForce discussion for 200 hp.  That sounds about right.

[Barry]

Kent,

Hope your vacationing somewhere and that everything is OK. Haven't seen any posts from you for awhile. Maybe I just missed one.

Barry

 

Update - I heard from Kent and he is fine. Just vacationing from the site.

Not sure why the whole thing got re-commented, but it works

Edited August 22, 2019 by Barry