Pixhawk 3.3.3 slow yaw at first flight attempt


I just finished mounting my hexa X6. The setup is:

  • 3DR Pixhawk with APM 3.3.3
  • Tarot X6 960 frame
  • Tarot 5008 motors
  • 18x55 CF props
  • T-Motor 40A ESCs
  • UBlox M8N GNSS external GPS
  • FrSKY X9D+ and X8R receiver
  • 10A Tattu 25C LiPo

Everything has been calibrated, from ESC to Radio.

At first flight attempt, in Stabilize mode, I’ve been able to just lift it of 1 cm. (yes, actually not lifted) because the X6 starts to slowly yaw counterclockwise.

The yaw stick from the radio TX does NOT control yaw, despite the radio is calibrated and it correctly reports its values on the APM Planner on my Mac (connected with SIK V2 telemetry radio to the copter).

I tried to use Loiter mode, and the copter flipped backwards upside down.

I remember to have checked the motors wiring according to Ardupilot Wiki, will double check today.

Anyway, what could be the problem?

Another strange behaviour is that APM Planner reports me FCU errors randomly: bad accel health, for instance, but if I power cycle the copter, it disappears.

Any help would be very very appreciated.


If you can get the log off the copter and post a link from google drive or one drive we can see what was going on. A slow yaw seems to indicate a motor is not level and is pointing in that direction.


I will download it later and will post it here. Thanks.

Here you are:


Please find the log here.

Thank you very much.

Your configuration will not fly. All your PID values are zeroed out so there is no control. I would follow the instructions on the following page to reset your PID’s to something that should fly.


You can also save them on the advanced tab prior to resetting them.

You will also need to re-due all the setup calibrations again as well.


Thanks @iseries your support is decisive. I asked before to setup but it has been told me that I could keep the PID at zero…
So I will reset them tomorrow. Can I just copy the settings or do I have to reset the Pixhawk and setup again the radio?

If you know what they were you should be fine otherwise they will be populated with the defaults if you a reset. I would recalibrate everything since a few items looked off.


Thanks Mike and sorry for my late reply.

I hope to find the time to reset and rebuild everything tomorrow and test it the first good weather day…

I will post here the news.

Thanks again.