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More testing with OAT and Static Ports.

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Ray.R.Doerr(at)sprint.com
Guest

Posted: Tue Jul 03, 2007 5:48 am Post subject: More testing with OAT and Static Ports.

Over the weekend I changed out my flat faced static ports from Cleveland Tools to there new dome faced ones.  When I called them about the error (TAS was 5 - 6 knots low on my Dynon versus 4-way GPS TAS) I was having with the original flat faced ones, they sent me the new dome faced ones at no charge (awesome folks at Cleveland).  I also mounted another OAT in my left wing on the wing spar flange right in front of the middle inspection plate, which was connected to a General Purpose input on my Dynon Engine Monitor.  My other OAT is mounted in the aft half moon bulkhead under the emp fairing, which is connected to the compass module for the Dynon EFIS.

	Well with these changes completed, Loal Wood (RV-7, XP-360 injected with cold induction, Dual OAT's in each wing) and Tom Deutsch (RV-10, IO-540, OAT in NACA vent inlet connected to Dynon Compass Module) went up to do some comparison testing.  Loal was reading 61 degrees on both of his OAT's which were out in each wing, while I was reading 61 on my OAT that was out in the wing on the Dynon EMS, but my was reading 67 on my OAT under the emp fairing.  Tom on the other hand was reading 68 on his OAT in the NACA vent inlet.  Since all three of us had Dynon EFIS and EMS's with OAT connected, we concluded the correct OAT was from the OAT's that were mounted out in the wing regardless if they were connected to the EFIS or EMS, since Loal's both read the same value both on the ground and in the air.

	Now as for the TAS error I was seeing after my post from last week, which showed my Dynon TAS being 5 - 6 knots low.  I did another run and here are the numbers.



	

TRK	IAS	TAS	GS	OAT	MAP	RPM	FF	ALT	DA

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

0	144	168	182	60	22.0	2450	14.6	8500	10420

90	144	168	164	60	22.0	2450	14.6	8500	10420

180	144	169	158	60	22.0	2450	14.6	8500	10420

270	144	168	176	60	22.0	2450	14.5	8500	10420

            ----

            170.3

	From this I concluded that the domed faced static ports have corrected my TAS error to the point where I am reading 1 - 2 knots low versus 5 - 6 knots before.  I believe this is the same experience that Tin Olson has seen when he changed his static port out.  Also since I now had the OAT on the EMS with Dynon's latest 3.0RC4 beta code which now has the % HP, it was showing that this test run was at 74% power ROP.  There is no doubt my speeds would be faster trying this again at a DA of 8000 versus the 10420, but I need to leave something for another day.





Thank You

Ray Doerr

N519RV (40250) Hobbs 266

Tim Olson

Joined: 25 Jan 2007
Posts: 2879

Posted: Tue Jul 03, 2007 6:13 am Post subject: More testing with OAT and Static Ports.

Ray,



You are absolutely to be applauded for your input and efforts on this.

It's very refreshing to see someone take the time to validate everything

to a good extent.  Indeed you're right....I had the same flat-faced

ports and was reading 6.5-7.5kts low, and after swapping them for

the domed ports I'm now about 1.8kts low if my repetitive testing

averages are right.  -1.8 is good enough for me, although the

perfectionist in me gets tempted to make it better...luckily the

lazy man in me tempers that a bit.



Also, that was great of you to take the time to verify OAT probe

positions and temp errors. Hopefully people will take that to

heart.



Tim Olson - RV-10 N104CD - Flying

do not archive

Doerr, Ray R [NTK] wrote:

 	  Quote: 	
		   

 <Ray.R.Doerr(at)sprint.com>

 

 Over the weekend I changed out my flat faced static ports from

 Cleveland Tools to there new dome faced ones.  When I called them

 about the error (TAS was 5 - 6 knots low on my Dynon versus 4-way GPS

 TAS) I was having with the original flat faced ones, they sent me the

 new dome faced ones at no charge (awesome folks at Cleveland).  I

 also mounted another OAT in my left wing on the wing spar flange

 right in front of the middle inspection plate, which was connected to

 a General Purpose input on my Dynon Engine Monitor.  My other OAT is

 mounted in the aft half moon bulkhead under the emp fairing, which is

 connected to the compass module for the Dynon EFIS. Well with these

 changes completed, Loal Wood (RV-7, XP-360 injected with cold

 induction, Dual OAT's in each wing) and Tom Deutsch (RV-10, IO-540,

 OAT in NACA vent inlet connected to Dynon Compass Module) went up to

 do some comparison testing.  Loal was reading 61 degrees on both of

 his OAT's which were out in each wing, while I was reading 61 on my

 OAT that was out in the wing on the Dynon EMS, but my was reading 67

 on my OAT under the emp fairing.  Tom on the other hand was reading

 68 on his OAT in the NACA vent inlet.  Since all three of us had

 Dynon EFIS and EMS's with OAT connected, we concluded the correct OAT

 was from the OAT's that were mounted out in the wing regardless if

 they were connected to the EFIS or EMS, since Loal's both read the

 same value both on the ground and in the air. Now as for the TAS

 error I was seeing after my post from last week, which showed my

 Dynon TAS being 5 - 6 knots low.  I did another run and here are the

 numbers.

 

  TRK	IAS	TAS	GS	OAT	MAP	RPM	FF	ALT	DA 

 ----------------------------------------------------- 0	144	168	182

 60	22.0	2450	14.6	8500	10420 90	144	168	164	60	22.0	2450	14.6	8500

 10420 180	144	169	158	60	22.0	2450	14.6	8500	10420 270	144	168	176	60

 22.0	2450	14.5	8500	10420 ---- 170.3

 

 

 From this I concluded that the domed faced static ports have

 corrected my TAS error to the point where I am reading 1 - 2 knots

 low versus 5 - 6 knots before.  I believe this is the same experience

 that Tin Olson has seen when he changed his static port out.  Also

 since I now had the OAT on the EMS with Dynon's latest 3.0RC4 beta

 code which now has the % HP, it was showing that this test run was at

 74% power ROP.  There is no doubt my speeds would be faster trying

 this again at a DA of 8000 versus the 10420, but I need to leave

 something for another day.

 

 

 

 

 Thank You Ray Doerr N519RV (40250) Hobbs 266

 

 

 

 http://www.matronics.com/Navigator?RV10-List

rleffler

Joined: 05 Nov 2006
Posts: 680

Posted: Tue Jul 03, 2007 1:53 pm Post subject: More testing with OAT and Static Ports.

It doesn't appear that Cleaveland has updated their web site.  What's the

new part number?  I'm assuming they are the same price as the old ones?



Has anyone measured the ones from Rivethead-Aero yet?   Do they exhibit

similar issues?



--

_________________
Bob Leffler
N410BL - Phase I
http://mykitlog.com/rleffler

rv10builder(at)bellsouth.
Guest

Posted: Tue Jul 03, 2007 2:16 pm Post subject: More testing with OAT and Static Ports.

I know Mike follows this list...he can probably answer.



BTW Mike...can you have a supply of the new static ports on hand at OSH'08?



Brian

#40308

Nashville, TN



Bob Leffler wrote:

[quote] 



 It doesn't appear that Cleaveland has updated their web site.  What's the

 new part number?  I'm assuming they are the same price as the old ones?



 Has anyone measured the ones from Rivethead-Aero yet?   Do they exhibit

 similar issues?



 --

KiloPapa

Joined: 24 May 2006
Posts: 142
Location: Pearblossom, CA

Posted: Tue Jul 03, 2007 6:00 pm Post subject: More testing with OAT and Static Ports.

Thanks for the update.



Kevin

40494



----- Original Message Follows -----

From: "Doerr, Ray R [NTK]" <Ray.R.Doerr(at)sprint.com>

To: <rv10-list(at)matronics.com>



 	  Quote: 	
		      Now as for the TAS error I was seeing after my post

from last week, which showed my Dynon TAS being 5 - 6 knots

low.  I did another run and here are the numbers.

_________________
Kevin
40494

do not archive

rv10builder(at)bellsouth.
Guest

Posted: Tue Jul 03, 2007 6:40 pm Post subject: More testing with OAT and Static Ports.

Sorry...OSH'07.  Wow...I just added another year to my construction by 

mistake!



do not archive



rv10builder wrote:

[quote] 



 I know Mike follows this list...he can probably answer.



 BTW Mike...can you have a supply of the new static ports on hand at 

 OSH'08?



 Brian

 #40308

 Nashville, TN



 Bob Leffler wrote:

> 

>

> It doesn't appear that Cleaveland has updated their web site.  What's 

> the

> new part number?  I'm assuming they are the same price as the old ones?

>

> Has anyone measured the ones from Rivethead-Aero yet?   Do they exhibit

> similar issues?

>

> --

elhershb(at)comcast.net
Guest

Posted: Wed Jul 04, 2007 6:33 am Post subject: More testing with OAT and Static Ports.

Pardon my comment on this. When Cleaveland Tool came out with the new domed static ports I became worried because I had the original flat ones installed. I called Mike about this and was told that the reason for the design change was to account for the fact that many were priming the inside of the skin. When doing this it took away the designed protuberance of .010". When the back side is primed the face of static port becomes practically flat with the outside of the skin. This will not allow them to be in clean undisturbed air.

     So if you have primed the inside skin, you either need the new domed static ports or you need to machine the flat ones so they stick out .010" above the outside skin.

 

 Ed Hershberger

 Wings Top Skins

 N410EP (res)

 

 Bob Leffler wrote: 

 --> RV10-List message posted by: "Bob Leffler" <rvmail(at)thelefflers.com> (rvmail(at)thelefflers.com) 

 

 It doesn't appear that Cleaveland has updated their web site.  What's the 

 new part number?  I'm assuming they are the same price as the old ones? 

 

 Has anyone measured the ones from Rivethead-Aero yet?   Do they exhibit 

 similar issues? 

 

 --

VHMUM(at)bigpond.com
Guest

Posted: Wed Jul 04, 2007 2:17 pm Post subject: More testing with OAT and Static Ports.

I just dont get it with my 6 we just used the Vans  pop rivet. All acurate and no stuffing around reinventing ....whats the  diference with the 10.....please excuse my ignorance.

  

 Is the location wrong?

  

 Chris 388

 [quote]   ---

sam.marlow

Joined: 25 Feb 2006
Posts: 99

Posted: Wed Jul 04, 2007 2:38 pm Post subject: More testing with OAT and Static Ports.

It's driving me crazy, I wished I knew. I've installed the new Cleveland ports, and it helped, but it's still not correct. Van's can do better than this, I'm disappointed.

Sam



---- The McGough Family <VHMUM(at)bigpond.com> wrote: 

[quote] I just dont get it with my 6 we just used the Vans pop rivet. All acurate and no stuffing around reinventing ....whats the diference with the 10.....please excuse my ignorance.

 

 Is the location wrong?

 

 Chris 388

   ---

jwt(at)roadmapscoaching.c
Guest

Posted: Wed Jul 04, 2007 4:34 pm Post subject: More testing with OAT and Static Ports.

Does anyone know if the ports from SafeAir have the same errors that the

Cleveland flat ports have?



John Testement

jwt(at)roadmapscoaching.com

40321

Richmond, VA

Paint prep and interior

do not archive

--

VHMUM(at)bigpond.com
Guest

Posted: Wed Jul 04, 2007 5:47 pm Post subject: More testing with OAT and Static Ports.

Has anyone tried the vans method?



---

DAVELEIKAM(at)wi.rr.com
Guest

Posted: Wed Jul 04, 2007 7:32 pm Post subject: More testing with OAT and Static Ports.

Good question, I installed the Safe Air ports.  I second.  Any known errors?



Dave Leikam

40496



do not archive

---

rvbuilder(at)sausen.net
Guest

Posted: Thu Jul 05, 2007 5:11 am Post subject: More testing with OAT and Static Ports.

The common theme here is that the static ports must extend out approx .010 in order to clear the boundary layer and give accurate readings.  Van's do this from the shear fact that they are a domed pop rivet.  A lot of people are concerned, and I believe a few have experienced, that the van's pop rivet doesn't hold the static tubing on with any type of long term positive grip.  Other than that thousands are flying with the pop rivet.



  With the -10 many people just didn't like the idea of a cheesy pop rivet static port and just as many are planning on using the -10 for IFR so it would seem prudent to use something better like the Cleaveland or SafeAir.  Back when I made my decision there was a lot of conjecture on why people would see various errors and I discussed this briefly with SafeAir and went with their package anyway knowing I might have to replace the ports (I mainly was interested in the tubing and connectors).  It was acknowledged back then that there was a potential for problems but most people didn't seem to care that they might have an error as they fly for fun.



  So we now know, with some hard data, that you probably need at least a .010 protuberance for accurate readings.  I would be interested to know if .015 would clear up that additional 1-2 knot discrepancy.  If your ports are flush you will probably have an error.  If you use Van's pop rivet method or anything else that sticks out a bit you will probably be ok.



Michael Sausen

-10 #352 Limbo.



--

Tim Olson

Joined: 25 Jan 2007
Posts: 2879

Posted: Thu Jul 05, 2007 5:47 am Post subject: More testing with OAT and Static Ports.

I'd agree with everything Michael just said.  It really is just

sticking the port out a bit that fixes things.  I had my old

Cleveland flat ports in, and cut flat washers to tape over the

area and that did the job too as a test...just getting the ports

to stick out a bit.  The pop-rivet will do that, and there's

probably many more ways, but as Michael also said, you want

something really good for IFR flight that securely holds

the tubing on, so the pop rivet doesn't cut it from a mechanical

perspective, even if it worked perfectly from an accuracy perspective.

Also, I know, cleveland said that the primer is the cause of the

flat ports not working right.  While that may add to the

poor function of the flat ports, IMHO, if the primer is enough

to wreck it's function, then they weren't NEARLY stuck out

enough to begin with.  Even the domed ones don't stick out that

far, and if I were building my own, I'd probably want to at

least test them being another .020-.030 stuck out than

the domed ones are.  It would be interesting if the additional

~2kt error would then go away.



So I don't think the location is much at fault at all, but it's

absolutely apparent that the static port must stick out from the

skin.  If the SafeAir ports do that, then you should be fine.

If not...don't expect much.



Also, if you don't paint the ports, the skin's thickness will

detract from how far the port sticks out, so apparently you

are supposed to paint the ports with the skins. Again though,

I think the ports should just be cut thick enough that they

can go on unpainted and still work.



Tim Olson - RV-10 N104CD - Flying

do not archive

RV Builder (Michael Sausen) wrote:

[quote] 

 <rvbuilder(at)sausen.net>

 

 The common theme here is that the static ports must extend out approx

 .010 in order to clear the boundary layer and give accurate readings.

 Van's do this from the shear fact that they are a domed pop rivet.  A

 lot of people are concerned, and I believe a few have experienced,

 that the van's pop rivet doesn't hold the static tubing on with any

 type of long term positive grip.  Other than that thousands are

 flying with the pop rivet.

 

 With the -10 many people just didn't like the idea of a cheesy pop

 rivet static port and just as many are planning on using the -10 for

 IFR so it would seem prudent to use something better like the

 Cleaveland or SafeAir.  Back when I made my decision there was a lot

 of conjecture on why people would see various errors and I discussed

 this briefly with SafeAir and went with their package anyway knowing

 I might have to replace the ports (I mainly was interested in the

 tubing and connectors).  It was acknowledged back then that there was

 a potential for problems but most people didn't seem to care that

 they might have an error as they fly for fun.

 

 So we now know, with some hard data, that you probably need at least

 a .010 protuberance for accurate readings.  I would be interested to

 know if .015 would clear up that additional 1-2 knot discrepancy.  If

 your ports are flush you will probably have an error.  If you use

 Van's pop rivet method or anything else that sticks out a bit you

 will probably be ok.

 

 Michael Sausen -10 #352 Limbo.

 

 --

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Thu Jul 05, 2007 3:51 pm Post subject: More testing with OAT and Static Ports.

Before Dr. Carl Cadwell built the first Epic LT Kitbuilt Single Engine

Turbo-prop, he finished a beautiful Lancair (N25CL) that used the

boundary layer disrupter in the attached picture.  This might help

clarify why the pickup port should Not be flush with the skin.  Notice

the accent color pinstripe on the lower red to bring out the clarity.

One Shot - lettering paint was used.



Just a Trivia Note: It was the completion of Dr. Cadwell's Epic that

caused Comp Air of Florida to whine about the competition and trigger

the secret 51% Committee Meetings.  Has anyone seen any progress from

the private committee?  I will wager Mass Produced Kit Build is here to

stay with non American QB labor.



John Cox - KUAO

#600



PS - I hear that the RV-12 with a new wing is ready for "Prime Time" OSH

'07



--

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wcurtis(at)nerv10.com
Guest

Posted: Thu Jul 05, 2007 6:33 pm Post subject: More testing with OAT and Static Ports.

I don't know about boundary layer disruptor but these are stock S-Tec (Meggit) static ports used on their autopilots.  I know this cause I have two of these on the tailcone sides of my Cardinal feeding the S-Tec 30 altitude hold.  Ironically, the stock static ports on the Cardinal are flush and forward of the cabin door.



William

http://wcurtis.nerv10.com/ 



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