[email protected] wrote:Putting OAT sensors inside air inlets worked very well.
Less danger of damage when cleaning the aircraft and no holes to the outside of the airframe.

On the ground as expected, they read higher but once you have airflow all OK.
If one wants a fairly aqurate density altitude readout on the ground one should consider not putting the sensor in the duct and find a shady place outside.

One of my sensors had already been installed under the wing, say a little behind and to the side of the aft part of the pitot tube.
Still reads higher to some extend until airborne.

Think I have more OAT sensors on the 180 than on the Airbus now.

My JPI sensor is in the wing root cover, just above the door as it swings open. It, as mentio1ned, is shielded & starting the engine doesn't seem to effect the readings. The sensor for my AV-20 is next to the pilot tube, and typically reads within a degree or two of the JPI. My Dynon D100 requires a temp sensor to make the "winds aloft" direction, etc. features function. It's in the side of the fuselage below the horizontal stabilizer, which worked out to run the harness from the remote compass, which is mounted behind the baggage compartment. On a hot day, they still read within a couple degrees of each other on the ground. When I initially installed the JPI, I installed the temp sensor in the belly, as there was already holes from an old ADF antenna or such, and I thought that'd prevent a new hole being drilled....nope, even back that far, the exhaust added like 30 degrees to the readings.

Hman442 wrote:

[email protected] wrote:Putting OAT sensors inside air inlets worked very well.
Less danger of damage when cleaning the aircraft and no holes to the outside of the airframe.

On the ground as expected, they read higher but once you have airflow all OK.
If one wants a fairly aqurate density altitude readout on the ground one should consider not putting the sensor in the duct and find a shady place outside.

One of my sensors had already been installed under the wing, say a little behind and to the side of the aft part of the pitot tube.
Still reads higher to some extend until airborne.

Think I have more OAT sensors on the 180 than on the Airbus now.

My JPI sensor is in the wing root cover, just above the door as it swings open. It, as mentio1ned, is shielded & starting the engine doesn't seem to effect the readings. The sensor for my AV-20 is next to the pilot tube, and typically reads within a degree or two of the JPI. My Dynon D100 requires a temp sensor to make the "winds aloft" direction, etc. features function. It's in the side of the fuselage below the horizontal stabilizer, which worked out to run the harness from the remote compass, which is mounted behind the baggage compartment. On a hot day, they still read within a couple degrees of each other on the ground. When I initially installed the JPI, I installed the temp sensor in the belly, as there was already holes from an old ADF antenna or such, and I thought that'd prevent a new hole being drilled....nope, even back that far, the exhaust added like 30 degrees to the readings.

Thanks for that response with real world experience!

MTV

[email protected] wrote:Right wing.
Cabin air inlet duct.
Temp sensor instalation.

I love this idea. I need a location for a OAT probe and just might do the same thing.

Okay, I now have an EDM OAT sensor mounted under the right wing root, in the wing root fairing.

I also have a uAvionix AV-30C OAT sensor in same position under left wing in wing root fairing.

Temps are identical on ground. Once airborne, left sensor runs on average 2 to 3 degrees higher than right.

I can only conclude that some engine heat is being slung under and around the fuselage, slightly impacting the left location.

MTV

A1Skinner wrote:

mtv wrote:

A1Skinner wrote:You want to put it outside of the prop slip stream and in ambient air. In the cabin vent may make it less accurate. Its really easy to just put it in an inspection panel which is how I've done all mine. Easy to access for maintenance as well.

Why outside the prop arc?

MTV

That way it is outside of the prop wash when sitting on the ground. I know EI specifies this in their install manuals, not sure about JPI. But it makes sense.

Actually, we do not make any mention of the prop arc in our installation instructions. They are as follows:

Mount the OAT Probe in an appropriate location on the aircraft, using the hardware supplied. The OAT
Probe is sensitive to air temperature changes. For this reason, do not mount the OAT probe in the path of
the cowl or engine exiting air (i.e., on the belly of the aircraft). Also, if the probe is mounted in the cowling
area near a turbo or hot cylinder head, radiant heat may influence the probe temperature. Other than these
considerations, the OAT Probe may be mounted in an air intake vent, on the side of the cowling or anywhere
else on the aircraft.