Yaw Errors - Hardware Issue?

Hi Folks -
Had a scary flight last night and looking for some insight on whether I have a new hardware problem. I normally fly over the lake without issues, but last night for some reason my MP switched to ATTI mode with 17 satellites visible at an altitude of about 80ft, a few hundred feet out over the lake. I have no idea why this happened, although the logs show a consistent series of Yaw Errors just before switching to ATTI and continuing for a bit after switching back to P-Mode. I’ve uploaded the log, and I have the 400MB DAT file if needed.


And here’s the share link on Airdata:


My compass and IMU readings were all in the green (great actually) from my take off point. IMU readings were .003-.004, and compass interference readings were all low double digits. It’s been a few weeks since I cal’d but I’ve flown several times without issue.

I can handle some random interference, but if this is a sign of a hardware problem (and thus I can’t trust my Mavic), I’d like to know so I can send it in. Is there any insight from the logs? Does it look like the compass got ‘stuck’ or is bad, or is there a way to determine if it was just random interference?

Thanks for any help or insight!

Your TXT flight log doesn’t contain much information other than the fact that something was negatively affecting the compass. Your DAT flight log might contain additional information that’ll explain what happened. If you’d like other people to comment on it, please upload it to a file sharing site (like Dropbox) and post the download link here.

I have a few questions about your flight:

  1. Where did you take off?
  2. Did you have any kind of metallic accessories attached to your Mavic?
  3. Did you have trouble controlling your Mavic after it switched to ATTI mode?

Here’s a link to the DAT file. I have the guys over at MavicPilots.com looking at it too. So far they think it was localized interference.


In answer to your questions:

  1. I took off from the beach, and all the IMU and compass readings were low and green at that location. Icon was pointed in the right direction. I was launching from my foldable (no metal ring) launch pad. No other metal or electronics around unless it was embedded in the dirt/sand.
  2. Nothing attached to the Mavic except my PGYTECH landing gear and some velcro strips for when I use extra strobes (they were not attached at the time).
  3. I did not have trouble controlling in ATTI mode…although I still need practice. I was able to control it via FPV until it switched back to P-Mode.

Thanks for any additional thoughts!

Here’s the section of the log where the Mavic switched to ATTI mode:

230.601 : 15114 [L-FDI]ns req:fdi,0to0,reason:fusion.gps_yaw_err,result:fail for same index
231.805 : 15174 [L-FLYMODE][Ctrl<1>] REQ_RC_NORMAL ATTI ctrl_atti
232.146 : 15191 [L-FMU/LED]action changed. imu error:ns_abnormal(3)
238.198 : 15493 [L-NS][AHRS] yaw aligned 1
245.425 : 15855 [L-FLYMODE][Ctrl<1>] REQ_RC_NORMAL ATTI_HOLD ctrl_gps_atti

I see @sar104 is already on the case over in your other thread. I don’t see anything in addition to what he posted there.

Thanks msinger - yes, @sar104 gave me some great info. At this point I’m going to write it off as a one time disturbance and assume it’s not a hardware issue (until it is). Thanks for the response!