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GRT EFIS & Pitot Static Check

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coop85(at)bellsouth.net
Guest

Posted: Tue Sep 26, 2006 2:06 pm Post subject: GRT EFIS & Pitot Static Check

I'm ready to start traveling around this great country in our RV-10 so I

started looking into the XPDR Mode C certification and Pitot Static checks.

I know the XPRD encoder check is required to operate Mode C.  I spoke to the

local avionics guy and he said they remove the altimeter and encoder from

the airplane and hook it to the test equipment.  Not possible with the GRT

EFIS so we are looking into how to actually do this.



The questions are: 

 - is the pitot static check (run it up to 20K and see how it responds)

required for an experimental to fly IFR?

 - How have folks performed the pitot static check (if required) and the

XPDR encoder check with a GRT EFIS?



Thanks

Marcus



Do not archive

indigoonlatigo(at)msn.com
Guest

Posted: Tue Sep 26, 2006 3:45 pm Post subject: GRT EFIS & Pitot Static Check

When I have had my bi-annual transponder certification on my sailplane, all 

they did was to hook a pressure device to the single airline going into the 

encoder and then run through all the different frequencies on the 

transponder while changing the pressure into the encoder to verify it is 

functioning correctly.



Mode C has nothing to do with EXPERIMENTAL catagory, but is required for 

Class B airspace, so to with Class A(IFR).  I am unfamiliar with the GRT 

EFIS, does this have its own encoder built in or is it too connected to a 

seperate encoder? If seperate, would it not be the same as my above test.



No one has ever checked the entire static system for leaks while checking 

the transponder certificaion.



I'm not clear on how a static leak or error, would be discoverred if both 

the encoder and the altimeter are hooked to the same static system? Approach 

control radar does not determine ones altitude, that's why we have mode C.  

The encoder is set to 29.92 and then we set the manual altimeter to current 

barometric pressure, but if the encoder is hooked to the same static line 

both will have errors when we give our initial reporting altitude. even when 

they correct for the difference in barometric pressure, current vs. 29.92



I need a little help on this.



JOhn G.

 	  Quote: 	
		  From: "Marcus Cooper" <coop85(at)bellsouth.net>

Reply-To: rv10-list(at)matronics.com

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

Subject: GRT EFIS & Pitot Static Check

Date: Tue, 26 Sep 2006 18:05:05 -0400






I'm ready to start traveling around this great country in our RV-10 so I

started looking into the XPDR Mode C certification and Pitot Static checks.

I know the XPRD encoder check is required to operate Mode C.  I spoke to 

the

local avionics guy and he said they remove the altimeter and encoder from

the airplane and hook it to the test equipment.  Not possible with the GRT

EFIS so we are looking into how to actually do this.



The questions are:

  - is the pitot static check (run it up to 20K and see how it responds)

required for an experimental to fly IFR?

  - How have folks performed the pitot static check (if required) and the

XPDR encoder check with a GRT EFIS?



Thanks

Marcus



Do not archive

coop85(at)bellsouth.net
Guest

Posted: Tue Sep 26, 2006 4:43 pm Post subject: GRT EFIS & Pitot Static Check

John, 



  The GRT encoder is built into the system and the same computer drives both

the encoder and altimeter display so there's not going to be any difference.

In that regard I guess I just have to shell out $75 for the Mode C sign-off

even though it's a waste of time.  As for the leak, I suspect they use a

calibrated vacuum to raise the simulated altitude to make sure the altimeter

reads the same.  As for necessity, I doubt a leak would be that catastrophic

as the pressure inside and out of the airplane are similar (as indicated by

the alternate air source on most airplanes being in the cabin), although not

exactly the same.  Definitely an issue with pressurized airplanes, but I

don't have one.



What it really comes down to is I know I need the transponder (really

encoder) certification to turn on the Mode C.  Right now I just tell center

every flight that I'm negative Mode C, but I'd sure like to turn it on.

What I'm wondering, is if a pitot-static check is required for IFR flight?



Marcus

40286

Do not archive

--

jesse(at)itecusa.org
Guest

Posted: Tue Sep 26, 2006 4:58 pm Post subject: GRT EFIS & Pitot Static Check

Our local avionics guy did the transponder check and some kind of

pitot/static check in the plane, then wired up a harness on his bench to

test the altimeter, encoder and the Dynon EFIS.  Is it not possible to do

something similar with the GRT?  He said that he needed to test everything

in the plane that was giving altitude information on his bench.



Jesse Saint

I-TEC, Inc.

jesse(at)itecusa.org

www.itecusa.org

W: 352-465-4545

C: 352-427-0285



--

dlm46007(at)cox.net
Guest

Posted: Tue Sep 26, 2006 4:58 pm Post subject: GRT EFIS & Pitot Static Check

The transponder check can be accomplished in the aircraft if it complies 

with the required frequency stability. If it passes frequency then proceeds 

to Mode C in the aircraft. The whole system is checked for leaks. Usually 

the static system is sealed and a manual vacuum pump in a tester is used to 

pump the system to an altitude a couple of thousand feet higher. The tester 

then waits to determine altitude loss over time ; i.e. how fast the system 

leaks down to ground level. If that passes, then the tester steps the 

equipment up to altitude in increments and checks for leaks at each 

interval. In most cases, leakage must be almost zero; however as altitude 

increases some minor leakage is allowed. During the incremental test the 

encoder is checked to see that the output to the transponder corresponds 

closely to the visual altitude on the test equipment and on the altimeter in 

the aircraft.



My recommendation is that as you are building you should have an avionics 

guy visit you fuselage while its open to check for leaks, Tightening 

fittings and use of Teflon tape can eliminate most leaks before the final 

test. Its a whole lot easier to check when the various connections can be 

accessed. Trouble shooting requires isolation of various parts of the system 

and can be a bear if you have to open up a lot of access panels to get to 

them.



As for the GRT, I suggest that the tester tap into the static system and 

check for leaks, and then look for the correspondence on the GRT altitude 

readout. The test equipment will show transponder altitude output. BTW, 

encoders can have errors and my ACK has two pots on the top to adjust the 

output higher and lower.



---

Tim(at)MyRV10.com
Guest

Posted: Tue Sep 26, 2006 5:05 pm Post subject: GRT EFIS & Pitot Static Check

I have a separate ACK A30.8 encoder that feeds my GTX330 and

GNS-480, but I previously did use the Air data of the EIS 6000

for my system too.  Next test I'll be having to use the

pinpoint since my air data is now coming from that.  During the

IFR pitot static test, they checked the pitot system for

speed and for leaks, and they checked the static system for

accuracy, but never did they have to remove it from the plane.

I do believe they hooked directly to the ACK at one point, and

since that is a TSO'd device, I consider that the one that

ATC would care about.  But, the one that I myself really cared

about was the EIS 6000 before (and the pinpoint now), since

that's the one that will keep me away from the ground.  I have

my ACK set for 10' resolution.  The cool thing about the EIS

though was that the air data came out so that my accuracy

was within something like 7' all the way to 20K, since you could

put in some calibration factors.  What's really cool too is

the pinpoint shows the *exact* same altitude as the EIS 6000,

and the *exact* same airspeed as well...and during the calibration

those were right on as well.  The pinpoint has been tested

at the factory to something like 8' accuracy from zero to 40K'

or something like that.



Then, in testing the transponder, they did like John's reply

said....they cycled through the various codes, checking to

see what altitude it reported and what code it showed.  I also

paid just that tad bit more and got the Mode S addition to

the IFR pitot static test done.  That way they can verify if

your Mode S TIS information is displaying and working properly.



But, at no point did any of the equipment get removed from

the airplane to accomplish this.  The cart was rolled next to the

rear step, and it was done inside a hanger.



If you can't accomplish a similar result with your local

place, maybe try calling around a bit.  You should

be able to do what you need.  Rumor has it though that

some people will not test the experimental, non-TSO'd

stuff.  The guy that did mine didn't have a problem with

it, but he was very happy that I had the ACK encoder there,

because it gave him that comfort factor.  To him, the

zeroing in on the EIS6000 was just a side benefit.  He

was very impressed with the accuracy of the system though.



Tim Olson - RV-10 N104CD - Flying

do not archive

Marcus Cooper wrote:

 	  Quote: 	
		   

 

 I'm ready to start traveling around this great country in our RV-10 so I

 started looking into the XPDR Mode C certification and Pitot Static checks.

 I know the XPRD encoder check is required to operate Mode C.  I spoke to the

 local avionics guy and he said they remove the altimeter and encoder from

 the airplane and hook it to the test equipment.  Not possible with the GRT

 EFIS so we are looking into how to actually do this.

 

 The questions are: 

  - is the pitot static check (run it up to 20K and see how it responds)

 required for an experimental to fly IFR?

  - How have folks performed the pitot static check (if required) and the

 XPDR encoder check with a GRT EFIS?

 

 Thanks

 Marcus

 

 Do not archive

dlm46007(at)cox.net
Guest

Posted: Tue Sep 26, 2006 5:05 pm Post subject: GRT EFIS & Pitot Static Check

leakage for IFR is not acceptable. Check FAR 43 appendix E and F.

---

deutscht(at)rhwhotels.com
Guest

Posted: Tue Sep 26, 2006 5:05 pm Post subject: GRT EFIS & Pitot Static Check

Can we do our own certifications if we have received a repairman's

certificate issued by the faa on our airplane?



--

Tim(at)MyRV10.com
Guest

Posted: Tue Sep 26, 2006 5:21 pm Post subject: GRT EFIS & Pitot Static Check

Yes, the pitot static check is required for IFR flight, to the

best of my knowledge.  Why anyone would fly IFR without one would

be beyond my understanding.



Tim Olson - RV-10 N104CD - Flying

do not archive

Marcus Cooper wrote:

[quote] 

 

 John, 

 

   The GRT encoder is built into the system and the same computer drives both

 the encoder and altimeter display so there's not going to be any difference.

 In that regard I guess I just have to shell out $75 for the Mode C sign-off

 even though it's a waste of time.  As for the leak, I suspect they use a

 calibrated vacuum to raise the simulated altitude to make sure the altimeter

 reads the same.  As for necessity, I doubt a leak would be that catastrophic

 as the pressure inside and out of the airplane are similar (as indicated by

 the alternate air source on most airplanes being in the cabin), although not

 exactly the same.  Definitely an issue with pressurized airplanes, but I

 don't have one.

 

 What it really comes down to is I know I need the transponder (really

 encoder) certification to turn on the Mode C.  Right now I just tell center

 every flight that I'm negative Mode C, but I'd sure like to turn it on.

 What I'm wondering, is if a pitot-static check is required for IFR flight?

 

 Marcus

 40286

 Do not archive

 

 

 --

dlm46007(at)cox.net
Guest

Posted: Tue Sep 26, 2006 6:43 pm Post subject: GRT EFIS & Pitot Static Check

No. check FAR 43 appendix E and F. The calibrated equipment is costly and 

you need the FAA's blessing. Neither IA or A&P is approved for same unless 

separately blessed.



---

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