Home > VansAirForceForums

- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics

Go Back   VAF Forums > Model Specific > RV-14
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Thread Tools Search this Thread Display Modes
Old 03-29-2017, 03:58 PM
Brent 801's Avatar
Brent 801 Brent 801 is offline
Join Date: May 2012
Location: Conroe, TX
Posts: 28
Default Pitot Tube wiring past Magnetometer

I'm preparing to run the wires from my Garmin GAP 26 heated pitot inboard to the fuse. Is there any concern about running the pitot heat wiring close to the Garmin Magnetometer which is installed in the left wing where a Dynon ADAHRS would by located if using Dynon?
Built and flying since 2012 RV-8 81764
Building RV-14A 140229
Donation 12/16
Reply With Quote
Old 03-29-2017, 05:17 PM
Walt's Avatar
Walt Walt is online now
Join Date: Aug 2005
Location: Dallas/Ft Worth, TX
Posts: 4,319

Pitot heaters are heavy current users, this means serious potential for magnetic interference. Best practice would be to run a twisted pair (pwr/grd) from the tube all the way to the switch and ground block and keep the wiring as far as practical away from the magnetometer, then keep your fingers crossed.
Walt Aronow, Dallas, TX (52F) RV7A, IO360, C/S, 1500+hrs

EXP Aircraft Services LLC
Specializing in RV Condition Inspections, Maintenance, Avionics Upgrades
Dynamic Prop Balancing, Pitot-Static Altmeter/Transponder Certification
FAA Certified Repair Station, AP/IA/FCC GROL, EAA Technical Counselor
Authorized Garmin G3X Dealer/Installer
Website:, Email:, Cell: 972-746-5154

Last edited by Walt : 03-29-2017 at 05:19 PM.
Reply With Quote
Old 03-29-2017, 05:57 PM
DerekS DerekS is offline
Join Date: Apr 2013
Location: Ontario, Canada
Posts: 33
Default My Experience

I have mine quite close to the pitot, and am using Dynon's temperature regulating probe which I imagine is noisier than just an on/off spike since it has to regulate.

First time I tested it was close enough to fail the self-test. In my case I was able to reroute the wires so that they were 6 inches further away, at which point I no longer saw any impact when I turned it on or off during the self test.

Distance really does matter a lot, and 3 or 4 inches is too close.

(In my case not a twisted pair install)

Glasair IIRG - Flying
RV-10 - Doors that latch :-)
2016 dues paid
Reply With Quote
Old 03-29-2017, 06:50 PM
KeithB KeithB is offline
Join Date: Mar 2014
Location: Granbury, TX
Posts: 84

Yes, pitot heat power will interfere with the Garmin magnetometer mounted on the ADAHRS shelf. I ran a power wire in the "bundle" in the wing with a ground to a rib by the pitot - failed miserably. Then I ran a ground wire (not twisted at this point as Walt has recommended) - better, but still failed. Then I rerouted the ground farther from the magnetometer, twisted it around the power wires(s) near the magnetometer and got better results. It still fails Garmin's interference test for about 3 seconds during power up and power down, but I called it a victory.
Keith Brown

RV-14A Builder - kit #136
N314KC - First flight Mar 8, 2017, Phase I compl Apr 3, 2017
RV-6A sold
Sport Pilot (weight-shift control) - Airborne XT912
Dues paid 12/2016
Reply With Quote
Old 03-29-2017, 06:56 PM
rockwoodrv9 rockwoodrv9 is online now
Join Date: Dec 2011
Location: Meridian ID, Aspen CO
Posts: 2,184

I know there are differences between the 9 and 14, so is there a reason the magnetometer located in the wing rather than the back tail deck area? Im not flying yet so I don't know how mine will work, but there isn't nearly as many wires back there as by the pitot. There must be a reason. Thanks
Meridian Idaho
O-320 D2A
Panel andWiring done
Final assembly and paint!
Reply With Quote

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

All times are GMT -6. The time now is 03:24 PM.

The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.