GRT EIS OAT sensor recovery factor

I am wondering if someone (Kevin?) has determined the recovery factor for the GRT OAT probe - in particular for the streamlined aluminium part from GRT, ideally mounted underneath an RV wing.
I’m using a recovery factor of 0.8 which is giving remarkably good result (within 2.3kts SD 1.4kts). This value was suggested in the old Aviation Formulary website but can range between 0.7 and .95.
I’m thinking my results are too good to be true so am hoping someone may have objectively measured the value.
Doug Gray

Doug,
I have a GRT Horizon and EIS, plus I use the aluminum streamlined OAT probe. What is recovery factor, and where do you program it? I must have missed it in the install manual, but my temp indication seems like it’s accurate.

Scott Hersha said:

Doug,
I have a GRT Horizon and EIS, plus I use the aluminum streamlined OAT probe. What is recovery factor, and where do you program it? I must have missed it in the install manual, but my temp indication seems like it’s accurate.

Click to expand...

I have the same set up, I didn't see anything about recovery rate either. I would also like to know more about it.

When converting from calibrated airspeed to true airspeed the ‘Recovery Factor’ coefficient considers how effectively the OAT probe accounts for the additional temperature rise due to compressibility of the airflow around the probe in the Indicated Air Temperature. It’s value is a function of the design of the probe and how it is mounted.
GRT makes no mention of this spec for their probe.
At RV airspeeds the temperature rise due to compressibility is minimal and is probably and most often ignored.
Google for Ed Williams Aviation Formulary pages for the OAT to TAS conversion equations.
Kevin Horton has lots of valuable information in the Flight Test section of this forum (where I should have posted this question) and addresses recovery factor as well.
Doug Gray