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Pitot control box in wing tip?

tims88

Well Known Member
Has anyone installed a pitot heater control box on the outboard side of the last wing rib? I'm thinking about installing mine there but I'm worried about water damaging the controller if/when any leaks in through the wing tip seam. Garmin confirmed that they don't use sealed connectors and that water could damage it if it gets in. However, I know a lot of people install magnetometers in their wing tips and I haven't seen anything that says those are built for water exposure so maybe it's not as big of an issue as I'm imagining?

If I hadn't already cut the hole in the skin for the pitot tube I would probably just move it one bay inboard so that I could install the control box next to the aileron bellcrank inspection panel but the opening I've already cut is too far away for that.

Screen Shot 2023-03-23 at 8.40.50 PM.png
 
You could just put sealant on the box where it´s needed.
A nice little aluminium rain cap on top of the box?

Good luck
 
Consider mounting it to a rib as close to the Pitot as possible. Minimize the light gauge wiring between the box & the pitot heater & the heavier gauge wire run length to the power source.
 
I have mounted them on the inspection cover inboard of the pitot tube.
It's in the wiring line, easy to get at if you need to and it's a good vacant area.
 
Thanks for the responses.

Unfortunately the inspection panel is too far away for the wires to reach from the controller to the pitot tube. Sealing the control box might work but I'm thinking about moving it one rib inboard to the blue circle in the updated screenshot. I'll have to put the controller on the inboard side of the rib because that's where flat side it. It will make it tough to get to if I ever need to remove it but hopefully I'll never have a reason to do that.

It does have the advantage of putting the controller close enough to the pitot tube location that I'll be able to pull the connectors down through the pitot tube when I have to remove the pitot tube. I've made sure that I can reach that inboard rib through the lightening holes of the outboard rib.

It's not the best idea but maybe it's not a terrible idea?

pitotcontroller.JPG
 
You don’t say which probe you’re using, but the Garmin control box is to be within 2ft of the probe.
One option could be to mount the control box to the spar using click bond stand off nut plates. It’s something I’m exploring now.
 
I was able to mount the GAP 26 control box to the rib nearest the pitot tube, all done through the inspection plate in a finished wing. A little tight but not a big deal. You can see from the wire bundle in this photo approximately where it is:

20210731_plumbing2.jpg
 
I was able to mount the GAP 26 control box to the rib nearest the pitot tube, all done through the inspection plate in a finished wing. A little tight but not a big deal. You can see from the wire bundle in this photo approximately where it is:

20210731_plumbing2.jpg

Any chance you could show how it's attached to the rib? Am just at this step myself and am looking at options.
 
You don’t say which probe you’re using, but the Garmin control box is to be within 2ft of the probe.
One option could be to mount the control box to the spar using click bond stand off nut plates. It’s something I’m exploring now.

I mounted mine this way.
I used the nutplate-on-a-string trick to mount regular nutplates on the back (forward face) of the spar web.
Fiddly but worked out ok.


B43FCC2D-1020-40BA-B305-BFEC2E478E06.jpeg

29B28B92-9E58-40D0-AE5B-7053E186F36F.jpeg
 
It would be better to drill holes in the rib rather than the spar web...
Even if the control box is only supported by 3 screws or needed a backing plate.
 
You don’t say which probe you’re using, but the Garmin control box is to be within 2ft of the probe.
One option could be to mount the control box to the spar using click bond stand off nut plates. It’s something I’m exploring now.

I am using the GAP 26 and yeah I came across that 2' limit in the manual. If only it was 3' then I think I could just put the box by the aileron bell crank inspection panel.

I do like the click bond idea since I wouldn't have to drill more holes in a rib. I'll take a look to see if putting it on the spar would make it easier for me to remove it than putting it on a rib would.
 
I was able to mount the GAP 26 control box to the rib nearest the pitot tube, all done through the inspection plate in a finished wing. A little tight but not a big deal. You can see from the wire bundle in this photo approximately where it is:

20210731_plumbing2.jpg

I like that support you've added for the pitot/AOA connections. I have been wondering if those tubes needed any kind of support and if so how to do it. Thanks for the picture.
 
Any chance you could show how it's attached to the rib? Am just at this step myself and am looking at options.

It's just some screws and nuts through the flat part of the rib - couldn't be simpler, see image below.

I like that support you've added for the pitot/AOA connections. I have been wondering if those tubes needed any kind of support and if so how to do it. Thanks for the picture.

Thanks - more details here: https://vansairforce.net/community/showthread.php?t=197793
 

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It would be better to drill holes in the rib rather than the spar web...
Even if the control box is only supported by 3 screws or needed a backing plate.

Checked with Vans first. No problem from their end.
The most important variable is being able to actually access and remove it through the access plate.
It’s tight in there.
 
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