painted OAT probe

[ve0kog]

My Dynon OAT probe got painted black, I'm sure by accident. It is located under the horizontal stab (also black). This results in a much hotter reported OAT on the ground but I'm curious how much of a problem this is during the flight, with the airflow over the probe hopefully normalizing the reading.

Relocating or replacing the probe or stripping the paint off it would be a bit of challenge. I wonder if it's worth the trouble.

Any ideas on how to determine the OAT error while in flight?

 

[Carl_Froehlich]

The short answer is yes, it would be worth the trouble.

My OAT (not painted) was originally mounted in the tail area. It read ~2 degrees above actual. I moved both OAT probes (one for each AHAHRS) to the near the first left wing inspection bay. Problem solved.

I used a single four #22 conductor shielded cable, two wires for each probe. This made cable routing easy and is more robust than just running single wires.

What drove me to this was picking up light but unexpected ice one day, even though OAT reading was 34 degrees. I accounted for the slight ram rise in OAT, but the error got me below freezing. The side benefit was a more accurate TAS reading on the EFIS.

Carl

 

[ve0kog]

I think it's possible to pick up icing in slightly above freezing temp. Before I jump to replace the probe I will try to measure the OAT with an alternative sensor. May be something low profile can be mounted under the wing, or at the tail tie down and send temp via bluetooth.

 

[Carl_Froehlich]

Anywhere near centerline on the fuselage (like the tail tie down) will read high from the exhaust gas. Halfway out on a wing is the right place.

Carl