Fred,
I have seen a number of installations and tried a few myself.
Flap area as you have heard works well.
Just aft of the rear wing attach (good airflow through the pip pin hole I
guess).
At the fairing for the stabilator just forward of the metal bracket TP12.
If centered it doesn't interfere with the stab.
In the tail post lower end, in a trigear with the bottom of the rudder cut
off as per the manual.
Under the passenger seat near the wing fillet out in the stream. (Retrofit
idea it put the magnatometer and OAT together under the pax seat. Quick and
easy worked great. On autopilots installed though.)
In a NACA duct coming into the cockpit. The duct was equipped with a plenum
off the NACA to allow ball type inlet control, and this gave room for the
probe.
In a tail fin mounted NACA duct which funneled air up to the cockpit.
In the 914 engine inlet metal duct work just forward of the air filter.
Note that his is subject to the heated duct and must be insulated from
that heat transfer. Terrible on the ground between sorties.
In the 914 duct on the vertical metal below the oil tank. (Ran high all the
time.)
In the 912 XS Airbox. Just under the filter in the fiberglass box, it is
not bad but is just a bit warmer than outside air, better if attached just
in the free air coming into the filter on the top of the airbox where it can
sense the NACA airflow coming into the engine...
Note, same problem on the ground above.
In the metal air inlet face just inside the fiberglass cowl on the XS.
Note, same problem on the ground as above. Lots of bugs too.
In a custom made flap bracket cover on the starboard side (a modified
teardrop, with a 1/4 inch hole dedicated to allow air to impact the probe
and go out through a vent in the rear of the teardrop.) Nicely done.
Supposedly worked and I can't see why not.
The above positions all worked in-flight OK.
Lessons learned:
Anything in the tail meant more wire, voltage drop and weight.
Anything in the engine, meant insulation from heat.
Anything on the outside of the skin meant hitting it when washing. Not
unlike civil air probes. They just stick it out the side of the aircraft
where convenient.
Anything on the gaps in the flight controls meant extreme care to assure no
interference.
Not so well working:
Mounted on top of the aircraft near the fuel vents in a mono. The sun
heated it and it was always high in the summer and just OK in winter.
In the port wing near the end of the flap in a Classic. Hot exhaust must
collect under the wing or something. Plus it was another connector to
disconnect. I had to move this clients probe to the starboard side.
In the cockpit tunnel for the mono forward of the gear just below the panel.
Seems hot air coming in from the leaky firewall was the culprit. Moved to
belly.
Good luck Fred.
Regards,
Bud
--------------------------------------------------
From: "Fred Klein" <fklein@orcasonline.com>
Sent: Saturday, October 04, 2014 5:13 PM
Subject: Europa-List: OAT probe location
>
> All,
>
> I offer half my kingdom to anyone who will give me a proven location for
> an OAT thermocouple which is part of my aftermarket EMS.
>
> with appreciation,
>
> Fred
>
>
>
|