G3X Flap configuration and calibration


I'm close to  first flight in my 10+ year ES project!  I'm working my way through the G3X configuration and calibration procedures, and am stuck on the flaps, which seems to be a rather common issue.  My setup includes two GDU 640's, GEA 24 and GAD 27, and a lot more.  Flap position sensor is the RAC model, mounted behind the flap torque tube.  I also have the CAXE solid state limit switches installed on the flap motor. (By the way, there is no flap motor coasting.)  Flaps worked just fine from the panel flap switch, that is until now.

I went through the Garmin configuration process, setting the relative position stops, and this worked just fine, that is it worked just fine in the GDU 460 configuration mode.  Then I saved my settings, and re-booted while still in configuration mode, per the on-screen instructions.  Looking good so far.  But upon returning to normal mode, flap indicator ribbon looked just fine, but the panel switch does not move the flaps at all, nothing, nada.  I repeated the entire process, after clearing all settings, with the same result - no flap operation in normal mode.  I have an inquiry into Garmin,  but so far no response.  They must be really busy. 

Anyway, any advice would be much appreciated.  This issue is the last issue on the airplane I have to resolve before first flight.  Certainly there is a lot more to do relative to the avionics, but I've got radio working, engine information, vibration test, magnetic interference test and magnetometer calibration working just fine. Thanks Jim Anderson



I would like to offer some advice but I have hydraulic flaps on my IVPT.  I'm not familiar with that flap system.


Hi James, I have messed with

Hi James, I have messed with this system on my plane with G3x.  Curious, do you have a momentary switch controlling flaps, and are expecting the flap display on the G3x located to the left of the HSI to move up and down?  This is the setup I have with a Ray Allen position sensor adjacent to the torque tube and I can check my configuration to recall how I got mine working.  Mine had stopped working and, after replacing the sensor, it turned out to be a G3x config issue that I went in and messed with and reset all of the relative positions.  Now that mine is working correctly, I have a notion to go back in and add more discrete positions to make it work a little more accurately.  You mentioned "stops" - mine doesn't have any stops per se, but just works off of relative position as a percentage based on the voltage of the sensor as the momentary switch is held down (or up).  If yours is exactly the same, I can pay close attention when I adjust mine and report back exact results.


Thanks for the suggestions. I

Thanks for the suggestions. I believe the problem is solved, with the invaluable help of Dave Buckwalter, or Avionics Systems.  Dave built my panel, and is assisting me in getting it up and running.  I try not to bring Dave in on questions until I have exhausted all other available avenues.  He is so kind and generous that I feel bad about taking up his time.  In any event, it does seem that the G3X installation manual (AQ) leaves a bit unsaid on the flap configuration/calibration procedure.  Dave walked me through it, and now it seems to be operating correctly.  The stops I mentioned are the "tic marks" available in the configuration/calibration process.  I do have a momentary flap switch for down flaps, and set the tic marks for 0, 10, 20, 30 and 40.  If you start the flaps fully retracted, at the 0 tic mark, then hold the flap switch down for about two seconds, it will send the flaps to 10 degrees and stop.  Same for 20, 30 and 40 (fully deployed) tic marks.  I'll need to double check, but I believe that you can retract the flaps in increments, but it is more of a manual process, holding the switch up until reaching the desired tic mark.  The importance of this, at least for me, is twofold:  First to enable incremental flap deployment in the pattern without having to look at the panel, and second to enable partial retraction of the flaps for go-around, until positive rate of climb, and altitude are nominal.  I have been taught not to retract the flaps fully on go-around due to loss of lift.  The bonus of all of this for me is that this flap control ability most closely mirrors my Cessna, thus reducing learning curve.