OAT probe location?

Best place to mount? GRT folks say inside the wing root.
Anyone ever do this? Other locations? Thanks.

I have mine on the starboard wing root fairing outside. Seems to work fine.

Whatever you do... don't install it in the NACA duct inlet in the side of the fuselage right behind the firewall/cowling. Enough heat from the engine is present there, to cause significant error in measuring the real OAT.
My RV-6 was built with its OAT probe there, and it always reads at least 8-10 degrees high, sometimes much higher. Even on a cool morning flight, when I open the cabin air vents, I get warm-feeling air coming in. A friend who built an RV-4 with NACA cabin air inlets put his there too... it reads high as well. Another friend of mine who built an RV-10 also put his there... same thing always reads high. When we finished the RV-8 in 2010, I knew of these bad readings so I located the Dynon's OAT probe in the NACA duct inlet on the bottom of the right wing (air inlet for the rear seat vent duct) since that is plenty far away from any heat coming off the engine, and it always reads accurate.

I plan to move my OAT probe on my -6 to the underside of the right wing, someday whenever I get around to it.

I would place them near the first access panel on your wing. This allows easy access if you need to replace/repair and it's out of the stream of the heat coming off the engine.

I have two of them, one connected to GRT and one connected to GTX 330 and both were installed in each of the NACA air inlet. They both were within 1 degree F at most and all indication seemed to be reading correctly. After reading much discussion on this forum, I moved one of them (GRT) to the wing root area and still reading pretty much the same compared to the one that is connected to the GTX 330.

I believe it is reading very accurately and I hope this helps.

I have two. One is located in the wing root and the other in the HS just inside the first bay. Easy access by dropping the back part of the wing root fairing or through the empenage fairing.
I had one in the NACA duct and it always read 10 deg. or so high.
Both of mine read within a degree of each other in their current locations.

Under the Horizontal Stabilizer


In the back, shaded by the HS.

GRT inside the wing root.

bruceh said:

In the back, shaded by the HS.

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Mine is there too.

Stuck mine behind the wing tank forward attach bracket.

rleffler said:

I would place them near the first access panel on your wing. This allows easy access if you need to replace/repair and it's out of the stream of the heat coming off the engine.

Click to expand...

This is where I placed mine. Just inboard of the first access plate on the left wing. Easy to get to the sensor and wiring.

rleffler said:

I would place them near the first access panel on your wing. This allows easy access if you need to replace/repair and it's out of the stream of the heat coming off the engine.

Click to expand...

+1.

I had them in my NACA duct (doh!) and found the OAT was reading way off! I did some research and found a few that put it on the wingroot fairing, but I thought it may pick up some heat from the engine...so I went further out. The access panel was a good spot, and could be replaced easier than most other locations. So far, it's worked out really well.

bruceh said:

In the back, shaded by the HS.

Click to expand...

Same here, but I haven't flown yet...

LIke them guys said ...

...adjacent to the first access cover on the wing. PLenty of room AND future access if needed.