RV9 OAT

[MJS]

I would like to put the OAT on the underside of the fuselage just behind the bulkhead at the rear of the baggage area. This would put it about 7' behind the firewall.

Is this going to be okay ?

Mark S.

[BH1166]

Nothing in potential heat flow is going to be accurate. Lot put out on underside of wing. Mine is pretty accurate +/-3 and mine is in pilot side fresh air naca duct. The error is heat from cowl, being it is so close. Just one opinion, others coming.

[Mel]

Originally Posted by MJS

I would like to put the OAT on the underside of the fuselage just behind the bulkhead at the rear of the baggage area. This would put it about 7' behind the firewall.
Is this going to be okay ?
Mark S.

You will still get noticeable heat at this point. If you are going to put it on the fuselage, the farther back the better. Many people opt for under the right hand horizontal stabilizer. This is where I put mine and it is pretty accurate.

[RV8JD]

Here is what Davtron says on OAT location:

"NOTES: THE TEMPERATURE SENSOR MOUNTING SHOULD BE IN A PLACE THAT IS FREE OF EXHAUST GASES OR COWL FLAPS AIRFLOW. THE IDEAL PLACE IS TWO FEET OUT FROM THE WING ROOT ON THE BOTTOM OF THE WING. SENSOR LEADS MAY BE LENGTHENED OR SHORTENED WITHOUT AFFECTING
CALIBRATION."

Here is what the Dynon SkyView manual says on OAT location:

"Sensor Location

The SV-OAT-340 is an outside air temperature sensor. In order for it work properly, it must be able to measure air temperature accurately. Avoid exposing the sensor to sources of heat that would interfere with outside air temperature readings such as:

• Direct sunlight
• Engine heat and exhaust
• Aircraft interior (back side of sensor)
• Heated air from the cabin exiting from an open window or cabin air exhaust port
• The installation area should have space for a nut and wires on the back side of the sensor. It is acceptable to extend or reduce the wire length if necessary. Reduce the wire length by cutting out the desired length from the middle of the wires and splicing together the remaining ends.
• If there is a backup ADAHRS in the SkyView system, it is acceptable to install a backup OAT sensor a few inches away from the primary sensor. Consider running primary and backup OAT sensor wiring together. Tape sensor wire pairs together to avoid confusion later."

FWIW, my RV-8 (IO-360-M1B) has a Dynon OAT probe on the aft fuselage under the right stab. A friend retrofitted a Davtron OAT probe (for an AV 30) for his RV-8 on the second outboard inspection panel of the left wing. We have compared OAT readings on several occasions when flying close together and they differ by 1°F at the most. I have heard anecdotally that the 'aft fuselage under the right stab' location does not work as well for RV's with larger engines (like those for the RV-10).

My RV-8:



My friend's RV-8:

[MacCool]

Anywhere in the line of the exhaust would seem to be a bad place for a temp sensor. I put my Dynon OAT on the outboard-most inspection panel on the underside of the left wing. The wiring was twisted and ran in the same conduit as the AoA and pitot tubing. Works fine in that location

[Dugaru]

Mine was originally in the pilot-side NACA duct and proved to be very inaccurate there. Reads perfectly now that it's out in the wing. Unfortunately now my true airspeed has gotten slower.

Originally Posted by BH1166

Nothing in potential heat flow is going to be accurate. Lot put out on underside of wing. Mine is pretty accurate +/-3 and mine is in pilot side fresh air naca duct. The error is heat from cowl, being it is so close. Just one opinion, others coming.

[Sportquattro]

I put mine in the inboard inspection panel on the Starboard wing. Works well and easy to access if needed.

[DarylT]

I had to move mine from the NACA duct. Opted for the Left wing inboard inspection bay cover. Works much better.

[eric.the.blonde]

I opted to put the sensors under the h-stab rather than the wing. The discerning factor was the location of the ADAHRS units which are mounted near the bulkhead behind the baggage bulkhead.