OAT Probe Location

[PaulSA]

I have a Dynon remote magnetometer located in the last wing bay. It has a connection for the OAT probe. I am considering fitting the probe to the last rib inside the wing tip. I'm trying to avoid yet another wire running down by the windshield.

Am I going to get an accurate reading? It seems to me that there are enough lightening holes around the place that air is going to move about fairly freely plus the aluminium skin should conduct the heat in and out fairly well.

Otherwise I was thinking under the tip but I'm a bit worried it might be vulnerable to tall people .......

[Nev]

Paul I think it’d need to be sensing the temp outside to read OAT, as it may get quite warm inside the sealed wing at times (and may also effectively sense TAT inflight - not that there’ll be much difference at low speeds).

[Nev]

Of course TAT could be real handy if you find yourself getting into the Mach regime and cold fuel issues.....

[zkelley2]

Ha! I think I'm going to stay home if the temp is approaching -58C.

I had mine in the fiberglass wingtip on the last airplane. I'll probably do this one in that metal that goes from the wing to the fuselage.

[rodsmith]

Garmin instructions specify outside in the airstream, best location underside of the wing.

[Rollie]

What do the installation instructions recommend? I have not heard of an Outside Air Temp probe being mounted anywhere but outside. Things like airspeed and altitude on an EFIS are calculated by not just the pitot-static input but also include OAT. They will only be as accurate as the input from those probes. I mounted mine on the bottom of the wing, just inboard from where the wing strut joins the wing so I would be less likely to bump into it than in any other location I could think of.

[tailwind]

I installed mine in the leading edge of the wing root fairing. Seem to work well and is out of the way here.

[PaulSA]

Of course, I don't see any reason why I shouldn't mount it on top of the wing tip ........

[jaredyates]

I believe the Dynon manual says theirs should be out of direct sunlight. One airplane I used to fly had two, one on each side of the nose. At low speeds we could see a difference on the sunny side. On our Bearhawk the probe is just aft of the strut attach point on the bottom and it works great there.

[Mark Goldberg]

On my old Patrol we were having problems getting Garmin G3X to light uo and start working. The problem was the OAT was not hooked up. At the time that surprised us.

we placed the probe near the wing root on the bottom of the wing a fott or so back from the leading edge. Always worked fine there. Mark

[Ray Strickland]

Ditto here.

[Steve W]

Also mounted the remote compass in the outer bay and placed my OAT sensor under the wing aft of the spar just inboard of the strut attach point. That way it is protected and so is the top of my head. On the last plane I built, I placed it under the root of the wing tight to the fuselage. No issues.

[kestrel]

With big enough tires, you can mount on the under side of the wing and heads are still safe.

[Mark Moyle]

My Pacer has two probes...both are installed on the bottom side of the wing root fairings that wrap around the wing at the windshield. One is for the Scandia mode C transponder. The second one is for the Ei engine monitor.

[Battson]

Mine is in that location, inside the wing "space" facing into the dead-space in the aileron pocket, exposed to ambient air but always shaded within the wing. Not exposed directly to the air stream. The temperature inside the wing tip would be substantially similar.

That location has proven to be accurate in all situations, noting that my plane is not painted dark colours.

[Battson]

P.S. my system is also Dynon, same hardware

[PaulSA]

That's interesting to hear. I think I will fit it at the rear of the outboard rib facing inboard so it should get ambient air from the lightening hole in the rear spar

[Nev]

Any issues with mounting the air temp probe on the lower fuselages? Has anyone tried this ?
I guess it could possibly get direct sunlight occasionally, so I’m wondering if this is an issue in practice.

[Battson]

Any place outside the plane lends itself to being damaged. I would somewhere with constant shade and mechanical protection at all times.

[Mark Dickens]

You want it out of the engine exhaust air flow, otherwise it will read too high. I will put mine under the wing

[PaulSA]

On my RV10, I initially mounted it underneath the fuselage right at the back. I thought it would be far enough aft to not be affected by the exhaust - I was wrong ......

[Flygirl1]

Ours (Dynon) are on the wing root fairing bottom left side just aft of the front window. Easily removed with the fairing with a quick disconnect. So far, works great.