Jump to content

installing OAT wire


Recommended Posts

Installing my JPI EDM-900 and down to inches.  One thing that is evading me is the ability to get the OAT thermocouple wire from the inspection panel at the base of the wing out to the inspection panel outside of the gear.  I don't know if other Mooneys have an inspection panel between those two ribs, but mine does not.  I was hoping to follow the oem wires through their grommets, WAY at the front edge of the wing.

Anyone have suggestions as to how to follow those wires?  I am currently thinking about something to slide along around the wires that will slide through the grommets, but I have no idea what that might be.

Thanks in advance!

James

Link to comment
Share on other sites

I relocated  an EI CGR30P  OAT just outside the right  landing gear door. Initially I tried routing the wiring from inside the  cabin  out to the wing but it was taking too long. I had some left over really thin aluminum tubing something like 1/8" o/d. and feed it from the wing inboard. It was much easier using tubing or I suppose 12 awg single conductor would work.

 

James '67C 

  • Like 1
Link to comment
Share on other sites

Working from the inspection panel next to the fuselage, out is neigh impossible.  My aileron push tube goes pretty much through the center of that inspection panel.

I'll have to give a larger wire a try, maybe I even have some 10 gauge.  My thinner wire (I think 14 gauge) just curled up inside (found another new use for my borescope).

Thanks!

James

  • Like 1
Link to comment
Share on other sites

Wondering if the pros have have a methodology that they use for this kind of long distance wiring challenge...

I think I Remember Some type of high tensile strength string being used to pull wires...

But, I don’t recall how they got that string in place to do the pulling... :)

 

See if Mr. Baker is around... @Baker Avionics (how to pull wires into the wing, OAT gauge install challenge...)

Best regards,

-a-

 

  • Like 1
Link to comment
Share on other sites

hum you must looking at inboard most panel. if you outboard  an inspection panel  or two and have maybe light shining down from the cabin  you should see from the inspection panel. I will probably remove the interior maneuver the oat wire to get to where you want it to go.  borescope may do the trick or I have an older used GO Pro   camera the one that looks like a  cube one I use that one  and light in the inspection bay works pretty well also .

  • Like 2
Link to comment
Share on other sites

You could use the lighting wire to pull it through. Just pull a replacement  Lighting wire with your oat wire to replace the one your pulling out. 
 

while you’re there might as well do both. 
 

I recently pre wired for my Dynon servos. Didn’t need the wing leveler vac hose anymore so I did this. 
 

they are now the most well protected wires in the airplane. 

9BE2BEE1-D0DA-4445-A130-D9303956C1D7.jpeg

  • Like 3
Link to comment
Share on other sites

use a glow stick, its what electricians use to pull wire.  HD has them. https://www.homedepot.com/p/Klein-Tools-15-ft-Splinter-Guard-Glow-Rod-Set-56415/204178243

 

I pulled wire for a 3-light strobe Whelen 600E strobe system with these. Theyre flexible enough to work into the wing from an inspection panel.

  • Like 5
  • Thanks 1
Link to comment
Share on other sites

I’ve had good success using a length of MS20253 piano hinge pin to install wires along side existing wires in wings. In essence a large sewing needle, just tape the new wire to the end of the pin.

Clarence

Link to comment
Share on other sites

10 hours ago, jetdriven said:

use a glow stick, its what electricians use to pull wire.  HD has them. https://www.homedepot.com/p/Klein-Tools-15-ft-Splinter-Guard-Glow-Rod-Set-56415/204178243

 

I pulled wire for a 3-light strobe Whelen 600E strobe system with these. Theyre flexible enough to work into the wing from an inspection panel.

+1 on these things for pulling/pushing wire.   I have a similar set but have not used them in the specific space under question.

Link to comment
Share on other sites

When I pulled the air tubes for my AoA I used small diameter all-thread.  Slide one length into the inspection hole and the rib lighting hole and join the second all-thread with an all-thread nut.  You can put a bend in the all-thread to make it to a lighting hole forward or aft. Jim

  • Like 1
Link to comment
Share on other sites

On 10/6/2020 at 6:23 PM, carusoam said:

Wondering if the pros have have a methodology that they use for this kind of long distance wiring challenge...

I think I Remember Some type of high tensile strength string being used to pull wires...

But, I don’t recall how they got that string in place to do the pulling... :)

 

See if Mr. Baker is around... @Baker Avionics (how to pull wires into the wing, OAT gauge install challenge...)

Best regards,

-a-

 

Well thank you for the plug! Lol Usually we will try to run some safety wire through then do a cone shaped tape job on the wiring  on the needed wiring and either use baby powder or something like vaseline to help with the sliding. Sometimes we will cut a pre-existing wire, pull it back with another string or safety wire and use that to stagger wires and pull it back through with the OAT wires and then splice the wire we originally used back together. Make sense? Lol. Either way, it isn't fun! I am glad I hire people to that these days! Lol. I hope that helps. 

  • Thanks 4
Link to comment
Share on other sites

Well, I got the wire through.  It was not easy and it required at least 4 tries, but I got it done.  I used the "light stick" method.  Except I used a fiberglass rod I had around from the aircraft tools section of Harbor Freight, cut it to length, and then made a point on one end.  This made getting the rod through the grommets much more straight forward.  The grommets are quite tight, which meant that getting the rod through with the wire attached was difficult and required 3 attempts...but it finally worked.

Man those inspection panels are small...

Link to comment
Share on other sites

Call JPI.  They will make you any size harness you want.  I was ticked that the first installer put it in the naca duct out the side without asking.  I later had that remedied and its now out in the wing where the OEM one was.  I forget how long I ordered but I bet they could look it up for you.  The installer told me the length I ordered worked well.

  • Like 1
Link to comment
Share on other sites

7 hours ago, hypertech said:

Call JPI.  They will make you any size harness you want.  I was ticked that the first installer put it in the naca duct out the side without asking.  I later had that remedied and its now out in the wing where the OEM one was.  I forget how long I ordered but I bet they could look it up for you.  The installer told me the length I ordered worked well.

Was there a problem with it being in the naca duct?  That is where mine is works great.  Reads the same Dynon probe mounted under the wing.

  • Like 2
Link to comment
Share on other sites

5 minutes ago, Floyd said:

Was there a problem with it being in the naca duct?  That is where mine is works great.  Reads the same Dynon probe mounted under the wing.

Often, TCs mounted anywhere near the cowl have a tendency to pick up a few degrees of temp because of proximity to the engine... when the sun is shining on it, the instrument error gets exacerbated...

When trying to avoid icing, a few degrees makes a big difference...

So... the preferred location for accuracy is out on the wing, far enough back to avoid any sunlight...

PP thoughts only, not an instrument guru...

Best regards,

-a-

  • Like 1
Link to comment
Share on other sites

7 hours ago, Floyd said:

Was there a problem with it being in the naca duct?  That is where mine is works great. 

That is where originally had my oat Probe for CGR engine monitor. My thought was  it would be like compass correct card and you just add/ subtract the correction value.

The problem with that theory was it all over the place it was never a constant value that I would need to add or subtract.

I confirmed this when Installed gad13 oat on my G5 . I installed the probe just outside left main gear door in inspection panel.  when I cross checking the temperature reading that is I was getting off the G5 to temp Probe in the front windshield. The would be usually close while the engine monitor temp Probe when it was mounted in naca duct air vent was some time 15 to 20 degrees difference when compared to the other two temp probes. The delta in temp was never constant.  So relocated it to just outside right main gear door. Now it agrees oat on the G5.

Just my experience.

Hope that helps.

James '67C

Link to comment
Share on other sites

New one-piece windshield on our ‘66E necessitates an electronic probe installation.   (The original ugly analog probe stuck straight out the windshield like a unicorn horn, in the full sunlight.)   Am hopeful that an electronic probe in the NACA duct on the fuselage is no worse than the original in terms of sunlight-induced error.  I don’t want to mess with snaking those wires through the wing.

Edited by Aviationinfo
Link to comment
Share on other sites

8 minutes ago, Aviationinfo said:

New one-piece windshield on our ‘66E necessitates an electronic probe installation.   (The original ugly analog probe stuck straight out the windshield like a unicorn horn, in the full sunlight.)   Am hopeful that an electronic probe in the NACA duct on the fuselage is no worse than the original in terms of sunlight-induced error.  I don’t want to mess with snaking those wires through the wing.


unfortunately, the naca duct location combines two errors, not just the one the unihorn has...

Sooo....

If you use your OAT instrument for...

  • calculating DA for T/O distance..... Or,
  • Planning A route out of icing....

These calcs can save your bacon...

Unfortunately, garbage in equals garbage out... when it comes to calcs...

Depends on how you use your plane...

If it is VMC only, the OAT gauge hardly gets used... with any precision...

PP thoughts only, not a CFI...

Best regards,

-a-

Link to comment
Share on other sites

Continuing on with where the excess warm air comes from....

It is not exhaust gasses causing the challenge... or we would be discussing the CO challenges that come with that...

for some reason our engines are surrounded with warm air that causes challenges in all directions...

If you have ever seen oil drips escape the cowling, and end up on the windshield... this would be another one...

PP thoughts only, not sure why warm air collects around the OAT sensor.... Apparently some more than others... :)

Best regards,

-a-

Link to comment
Share on other sites

5 hours ago, Aviationinfo said:

New one-piece windshield on our ‘66E necessitates an electronic probe installation.   (The original ugly analog probe stuck straight out the windshield like a unicorn horn, in the full sunlight.)   Am hopeful that an electronic probe in the NACA duct on the fuselage is no worse than the original in terms of sunlight-induced error.  I don’t want to mess with snaking those wires through the wing.

I wasn't interested in doing what I would consider half a job.  I wanted my information to be as accurate as it could be.

It really wasn't a big deal once I figured out how to do it.  Yes, you have to take the whole interior out of the pilot side (that could be lessened by putting it on the passenger side), and you have to pull a couple of inspection panels and be uncomfortable for a while, but as I said, using a fibreglass rod with a slight taper on the end, I could follow the wires and put it through the grommet relatively quickly.  Just make sure the wire is well attached when you pull it...that was as much my problem as anything.

I personally much prefer the placement under the wing, but its your airplane.

Link to comment
Share on other sites

7 hours ago, RobertGary1 said:

My probe is at the cut out for the fresh air intake below and ahead of the pilot window. I know the exhaust doesn’t go there. I have my JPI and my Garmin temp probes there. 
 

-Robert 

That's where my OAT probe is, but on the passenger side.

This is a not-very-good cropped photo that sort of shows it.

20201018_221230.thumb.jpg.632844486f3a61e150b2b591c4633f45.jpg

Seems to work well. But I also get to keep an eye on Carb Temp, which generally gets low first . . . .

Edited by Hank
  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.