Copter 3.3.3 crash on Auto mission end


I had a pretty bad crash about a week ago, and I’m trying to find the root cause of it before the next flight.

I had the copter running laps of about 1km, with manual re-switching to Auto for each lap, and it was fine until the 9:th lap. When it hit the last waypoint and was stopping, it started to wobble uncontrollably, unable to recover, while loosing altitude quickly. It did “glitch” maybe once or twice on earlier laps when hitting that last waypoint but nothing too severe.

Now I have a few theories about what could have caused the crash:

  • Aggressive PIDs? (copter was auto-tuned, seems to overshoot, pitching to 40 deg when DesPitch is 30)
  • Too heavy? (though hovers at 50% throttle)
  • Braking too fast when hitting the last waypoint? (don’t know what param controls this, some loiter PID?)

I’d really appreciate it if you’d download the ZIP with .log and .param (10MB) and have a look, if you have any ideas about what the main cause is, or if it’s a combination of the above. I’m not that great at interpreting logs yet. The frame is a Tarot FY650 with Tiger Motor MN4012-11 (400kV) motors, 15x7.5 props running on 6S, if that’s of any help.

Thanks in advance,