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I have mentioned the hazards of circling approaches  https://www.canardzone.com/forums/topic/18661-kents-long-ez-project/?do=findComment&comment=66249   and see that the recent Challenger crash at Truckee is a typical example that killed six people: circling to land in bad visibility, got in too close to the landing runway, stalled it in.   Juan Brown has a good analysis  https://youtu.be/VT6Z--HNqlM   but he does not bring up the "look angle" illusion that gets a pilot into a square corner turning final.  It is funny problem: pilot may see that he has put himself in a square corner turning final and needs to tighten the turn (increase G) but if he increases his speed to handle the G, it makes an overshoot more likely.  I have seen pilots even slow down to try to make the turn radius smaller.  Brrrr.

 


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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I started reading this accident report, expecting it to be the recent Long-EZ crash this week that killed Marc Borum.   http://www.kathrynsreport.com/2021/07/rutan-long-ez-n966ez-fatal-accident.html   It mentions the recent accident but mainly covers a 2017 midair of the same aircraft & pilot. Reports say he was getting a flight review in the recent accident; perhaps he just got the airplane repaired.    Fate is the hunter, eh?

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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This is a good test by Russ Meyerriecks worth repeating here.  He was not happy with his cooling (new engine) and tried VGs ahead of the NACA scoop.  Before VGs he had 4.3" water differential on his manometer.  With VGs, 6".  Quite an improvement.  Someone pointed out that the increase in manifold pressure in inches of mercury corresponds to the increase in water pressure.  In my experience, this is what you can expect with VGs like this.  (pic)

To repeat a story:  I put a pitot tube in my NACA one time and hooked it up to an ASI.  The ASI would rapidly fluctuate between almost zero to freestream velocity.  A couple of VGs like this smoothed it out quite a bit.  The ASI did not reach freestream velocity but it was much improved.  My theory is that the air wants to skip over the NACA and the VGs create a swirl that helps the flow go into the scoop.  Don't try this because it eventually broke my ASI.  Use a manometer of some time an piccolo tubes above and below the cylinders.

Quote

Both test flights had the following configuration:
* 6kft standard pressure, 55f OAT
* wide open throttle stabilized cruise
* ~2600RPM, full rich

Without VGs:
CHT1: 412f (hottest)
CHT2: 386f
CHT3: 398f
CHT4: 350f
Baffle Pressure Differential: ~4.3in/h2o
MAP: 23.6"

With VGs:
CHT 1: 377
CHT 2: 369
CHT 3: 386 (hottest)
CHT 4: 343
Baffle Pressure Differential: ~6.0in/h2o
MAP: 23.9"

Notes:
* Positive increase in cooling effect. My hottest cylinder #1 had a 35f degree drop
* The increase in cooling from the vgs appear to be effective in cruise only and not as much in takeoff and climbout. I'm still seeing consistently CHT3 spike up to 450f on takeoff and cooling off rapidly during the climb.
* I'm unsure why map increased slightly. Perhaps the vgs are directing more airflow at the intake filter and creating a "ram air" effect? Or maybe the engine is breathing easier with a higher pressurized lower section?

VG configuration:
4 ply bid right angle stock
dimensions: 1" high, 2.5" long
location: halfway between landing brake and beginning of intake naca
orientation: 2.5" apart center to center, 15deg angled inwards from airflow
glued on with clear RTV

 

IMG_3656.JPG


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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Here is a headset I found after Lightspeed discontinued their very light passive "QFR" model.  Cheaper than anything on the Spruce website at $100 and they do the job for me.  Virtually the same as the Lightspeed QFR.   I have a couple from them.  They don't seem to advertise anywhere

https://www.wicomheadsets.com/product-category/aviation-headsets/

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Here's another tip--no charge:  If you have a disqualifying medical condition, download the FAA AME guide and peruse the checklists for approving special issuances for a particular condition.  I had a melanoma removed about 6 years ago and had the required brain MRI (melanoma can move into the brain causing a seizure).  This year I put in my paperwork for a special issuance for another condition but neglected to see that a brain MRI is required EVERY TIME you renew with a history of melanoma.  My AME didn't catch it either so it will add another month or two to the process.  Here is a pic from page 115 of the AME guide.

melanoma.jpg


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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I was just trying to find a Varieze builder's site for future reference.  Couldn't find one.  I still see them being built and repaired but most built in the days of dial-up internet.   "currrrr, weeeee, dong, dong dong"   Doesn't sound familiar?  Then you are a youngster.  My first experience was dialing to a number in Las Cruces, NM that would link me to Rec.Aviation.Homebuilt.  It is still around apparently.  Here is the latest post   🙂

Screen Shot 2021-08-30 at 3.54.57 PM.png

  • Haha 1

-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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dial up internet   

 


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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before the internet - bbs - each had their own phone number!!!  Still have my Mac Plus (and it still works) - and a 56k modem - if the internet ever goes down....

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This welded-tube Varieze project has been very interesting to follow.  It is not really a Varieze anymore.  Look it up at Facebook: RaptorAirWorks.   I grabbed this latest pic of cooling for his Viking engine.  I think I would have tried something different.    I think there will be turbulence behind that canopy that will reduce the flow into the scoop.  Also interesting is his video of a failed centerspar test of a spar he bought from another builder.  It wasn't built right

https://www.facebook.com/Raptorairworks/videos/649202605129720/

 

145072044_3869729869743628_7467987927184518771_n.jpg


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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Had a scare recently when the buyer of my EZ removed the old Rocky Mountain engine monitor I had used and installed a new Dynon EIS + sensors and reported the engine and oil temp were running very hot.  Suspicions were leveled at  my homemade CHT bayonets and oil cooler setup.   🙂  It seems now to have been a problem with sensor selection, sensor setup, or just test flying in hot weather.  All is forgiven from my end.  It reminds me of the saying "When you hear hoofbeats, think horses, not zebras"

---------------------

Saw this pic on Vans Airforce complaining of flare leaks on a fuel line.  Most of the comments centered on the small size of the flare (upper right), which also looks undersize to me.  'Course, not tighten the B-nut could also have been the cause.  🙂  I have not had any problem getting leak-free flares but my fuel systems are low pressure.    Use the correct 37 deg aircraft flare tool, deburr the inside of the tube with a deburring bit or tool, use a drop of oil on the flaring tool, and check that the outside diameter of the finished flare is pretty close to the I.D. of the B-nut.  Second pic is a bonus.

attachment.jpg

Screen Shot 2021-09-21 at 3.44.49 PM.png

Edited by Kent Ashton
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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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3 hours ago, Kent Ashton said:

Had a scare recently when the buyer of my EZ removed the old Rocky Mountain engine monitor I had used and installed a new Dynon EIS + sensors and reported the engine and oil temp were running very hot.  Suspicions were leveled at  my homemade CHT bayonets and oil cooler setup.   🙂  It seems now to have been a problem with sensor selection, sensor setup, or just test flying in hot weather.  All is forgiven from my end.

Sorry, Kent, but since you're posting publicly, I'll respond the same. That is not at all my interpretation of what's going on. Since the sensor that is now on the plane is the exact same sensor with the exact same setup as the Dynon EMS was originally installed with, and the sensor was calibrated with a candy thermometer, any statement that the issue with high OT measurements was due to sensor issue is contraindicated by the evidence. Multiple flights with the calibrated sensor verified the high OT's.

Only after the oil lines and cooler were cleaned and reinstalled, the OT's returned to a normal 180F - 190F from the previously noted 240F - 260F. Although no debris or blockage was found in either, those were the ONLY things (other than the flapper door removal in the oil cooler ducting) that changed. The problem was NOT the sensor. It may or may not have been the duct door, the cooler or the lines - maybe there was an air bubble somewhere that prevented flow - I don't know. But what I DO know is that it was NOT a sensor issue.

Now, it's possible that the issue with high OT's was completely coincidental with the installation of the new EMS. It would be a substantial coincidence, since we did not touch the cooler or the oil lines during the EMS install, but anything's possible. In that case, both the RMI and Dynon EMS's would have been reading correctly.

So no apologies needed and no forgiveness required. Zebras, indeed.

Edited by Marc Zeitlin

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I look at it this way:  This airplane/engine combo flew several hundred hours before.  It apparently cooled well and the oil temp was normal, then the owner installed a new EFIS, wiring, and sensors and it suddenly overheated and the oil temp spiked.  I'm hearing horses.

The owner told us he checked the oil lines and found no obstruction.  The oil-cooler company said there was nothing much in the oil cooler when they cleaned it--it was new when installed.  No changes made to my air duct to the cooler although the owner removed the oil door that regulates the air flow but as I say, the duct-cooler-door had been fine before and I would bet it will be fine if re-installed.   My homemade CHT bayonets were not checked so they might have been just fine (I suspect they were).

So yeah, the new oil temp sensor was checked but that still leaves, wiring, grounding, installation error, settings error or some unknown problem interpreting the new EFIS.  

Quote

[owner said 2 days ago]  At 2,600 rpm, in the climb, the CHTs are in the low 390’s, the oil temps stayed in the 180’s to 190’s. I flew for about an hour. When I idled for the descent the CHTs, the OT, and the EGTs, all receded appropriately.   . . . I don’t have a real smoking gun. . . .   I have two extra OT sensors to show for it, as I went back to the Dynon single-wire sensor. I have another that seems incompatible with the Dynon system, and I have the GRT two-wire sensor Marc recommended. I’ve had all three in the aircraft, at some point and can’t really return them, so I guess I’ll sell them on ebay.

Can we agree the engine has returned to nominal?  You seemed to want to blame my installation/instrumentation and guessed that the engine was actually running very hot for the past year or two but there is no evidence to support that hypothesis and it does not explain why the new installation showed hot readings initially, but now it has seemingly returned to essentially match what I experienced, without any appreciable changes to the engine or trouble found.  Horses!


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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Saw this interesting way of cutting a wing cavity with a hot wire.  Good idea.  A long hotwire tends to bow and cut across the curves in the center.  The builder has a series of Youtubes about his project   https://www.youtube.com/user/howardyin/videos

Screen Shot 2021-09-27 at 10.52.52 AM.png

Screen Shot 2021-09-27 at 10.53.34 AM.png

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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On 9/6/2021 at 9:20 AM, Kent Ashton said:

This welded-tube Varieze project has been very interesting to follow.  It is not really a Varieze anymore.  Look it up at Facebook: RaptorAirWorks.   I grabbed this latest pic of cooling for his Viking engine.  I think I would have tried something different.    I think there will be turbulence behind that canopy that will reduce the flow into the scoop.  Also interesting is his video of a failed centerspar test of a spar he bought from another builder.  It wasn't built right

https://www.facebook.com/Raptorairworks/videos/649202605129720/

 

145072044_3869729869743628_7467987927184518771_n.jpg

Hi Kent

 

does he say how he tested the spar? It really is a show of you can’t be too careful when buying a built project. 

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There is video of his spar test either on his FB site or a website.    He bought the spar and says it was defective (it broke dramatically).   However nobody except a few European builders load-test structures—because the authorities made them.  If built to plans they are very strong.    Load testing done wrong can break perfectly good parts.

there is a write up and pics of Burt load-testing a donated canard that was rejected as too dry.   As I recall, it still went to about an 11g load before cracking.    You cannot see into a spar or winglet attachment so there must be an element of trust when you buy a project.    Does the builder seem reliable?   How did he checkoff steps in the plans?   Do the layups look good IAW Rutan’s guidelines?    Most builders are very careful;  I have seen a bad project but it was a builder who never saw another project under construction in the days before the internet.    These days there are many good builder sites you can study and compare to what’s for sale


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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17 hours ago, Kent Ashton said:

There is a write up and pics of Burt load-testing a donated canard that was rejected as too dry.

The writeup and some pics of this are in CP 45     http://www.cozybuilders.org/Canard_Pusher/1985-07_cp-45.pdf

   This "extremely dry layup" went to 10G before it failed.  I think the pic below is from that test

Canardtest copy.jpg


-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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Thank you for the reply and insight

the amount of weight on that is insane!!!

 

seeing how the build logs are done is great advice. I will for sure be studying the ones I am looking at. A lot of unfinished projects out there. 
 

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My Cozy has not flown in a year while I fiddled with getting a Special Issuance medical.  The medical approval finally came through--five months after submitting the paperwork.  It expires in 5 months but I think I will get back on Basic Med which will be good for two years.  Anyway  .. . .

The airplane had a worrying miss on one of the LIghtspeed Plasmas.  Low takeoff RPM and  an alarming miss running on that one Plasma.  I thought maybe it was fouled plugs.  Nope, they are almost new.  Plug wires are pretty new.  I thought maybe the screw-on sparkplug caps were loose.  Nope.  One time I had a Lightspeed box that suffered a broken connection to an internal chip.    It seemed to be a manufacturing defect but Lightspeed did not publicize it.  Bad on them.  I doubt thst is the probem here.

Ordinarily, the boxes are pretty stout.  One  time I had corrosion in a coil tower connection to the plug wires that caused an engine miss.  I see that Klaus says a disconnected sparkplug is very bad for the coils and a corroded connection could mimic that.   I suspect my problem is going to turn out to be a bad coil.   News at 11.   The nice thing about the Lightspeed is that they are pretty easy to troubleshoot.

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-Kent
Cozy IV N13AM-750 hrs, Long-EZ-85 hrs and sold

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grounding and connector issues seem to be my biggest bane on airplanes (esp when they have alum and copper connectors (like buss bar)). 

I found a great product that I use quite religiously called "de-oxit" https://www.amazon.com/CAIG-LABORATORIES-D100L-25C-Contact-Cleaner/dp/B0000YH6F8/ref=sr_1_6?dchild=1&keywords=deoxit&qid=1634164261&sr=8-6.  they have specialty formulas for various type connectors - but the above seems to be very adequate for not only cleaning assitance - but also corrosion protection (oxidation)...   (unfortunately this stuff is VERY pricy)

Congrats on a clean bill of health!!  Hope you get the squalks worked out! great weather to fly in the Carolinas!!!   I want to go up with you again (after you get this all worked out of course 😉 ).

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@Lyn - I actually bought this unit first - now I buy the refill and just reuse the applicator here.  The long tip allows good control and a LITTLE is all you really need.  I touch to the contact point - let it set for 5-15 min...  then wipe off with q-tip.  then with the other end of the qtip put one drop of fresh de-oxit and put a super light coating on per directions  to prevent further corosion.

they do have special versions for gold connectors and such - but this works for all (the specialty ones actually have particulate matter to encourage connection - I am not fond of that idea if I have tiny pins I wonder if there could be electrical bridging if applied to liberally).  

 

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