OAT Location

[Dayton Murdock]

Hi All
I am installing a new EFIS and I need to locate my OAT sensor. Can I install it in the lower wing root fairing and receive a reliable reading?

[db1yg]

Hey Dayton,

I would expect the wing root fairing to pick up some of the radiant heat from the cowl. I have two OATs and know that the NACA picks up about 6 to 8 degrees f. from the cowl and I would expect the fairing to also pick up some--although not as much. I tried the NACA, the tail fairing under the HS, and finally settled on the first available wing access panel. This also gave me easy access. It proved to be out enough to avoid any engine heat and shaded from direct solar.

Hope this helps.

Cheers,

db

[rleffler]

I concur with Dave. I have one OAT on each wing, adjacent to the first wing access plate.

bob

[Ironflight]

Hi Dayton,

Under the wing, outboard of any possible engine heat, is a great spot. That's where we put Tsam's (essentially mirrored the pitot position on the opposite wing. Another good one seems to be in the elevator horn access plate in the shade of the horizontal tail. I'd pick one of those for a retrofit - whichever gives you the least headache pulling wires.

I can't overemphasize the need for an accurate OAT in an EFIS airplane - so much of the cool stuff you get in an EFIS (like instant winds aloft) depend on TAS, which depends on OAT....you lose a lot when it isn't right.

Paul

[schristo@mac.com]

I have mine under the fiberglass tailcone fairing... works spot on. If sitting in the sun it heats up and reads high but as soon as you start moving the air flushes ouy and it is works remarkably well at all speeds and temps.

[JonJay]

Hey buddy.
I have two. One mounted as you suggest, under left wing root fairing towards the rear (EMS). One mounted under the right HS (EFIS). Both read withing a degree or two at all times.
When I had the EFIS sensor mounted in the NASA duct, it was consistantly high 10 deg, F.
FWIW

[DanH]

Mine like Paul's....mirror the pitot under the opposite wing.