Heading bug off 9deg. Level button also

[Donald_Eccker]

Been have this problem for quite a long time, Its time to fix it!
I'll set my Autopilot Heading bug and once engaged plane tracks 9-11 deg off to the left? lets say my setting is 322deg. it'll track at 312-313deg?
Also does the same with my Level button? plane keeps slowly turning left.
Both maintains good Altitude.
I've done all the Heading bug setups but I'm surely missing something ?
Please help!!

 

[PaulSS]

Have you tried recalibrating the magnetometer? It's an easy thing to try if you haven't already done so and may a lucky break.

 

[Donald_Eccker]

ill assume you mean the ADAHRS ill give it a shot.
thanks

 

[PaulSS]

No, I meant the magnetometer. Whether you have a separate one or whether you're using the internal one to the ADAHRS, you can recalibrate it in flight. It may be that you're calibration is just fine but it won't do it any harm to recalibrate and, who knows, it might be the magnetic heading that is giving you the snags.

 

[chriscalandro]

Sounds like that ADAHRS also isn’t mounted flat.

 

[Jim8JD]

I had the same problem with my SV Touch in my RV-6A. I performed the on-ground compass calibration again and checked it with the in-flight calibration and that fixed the problem. I suspect the on-ground compass calibration wasn't performed properly after the initial installation, since it had always been off since I started flying the plane at 24 TTSN. You can find the procedures in the SV Installation Guide ... Pg 20-6 - 20-8. The on-ground calibration is the most critical part. I did it with engine running and did the turns slowly and it worked well.