Please help in diagnosing crash!

Hi! Can anyone help us understand the cause of our plane crash last Feb 28, 2019? We successfully flew our newly built Skywalker for the first time and did some autotuning. Unfortunately, on our second flight, it crashed while we were repeating the autotune.

We would like to know what can possibly cause this. Attached are the log files. Thank you.

There are many things wrong with that flight log:

  • you are using a very old dev version of ArduPilot
  • arming checks are disabled
  • the aircraft appears to be badly unbalanced, heavy on the right wing and nose heavy
  • even after an auto-tune the roll control is very poor, with it barely managing to stay in control

For your next build pay more attention to details like CoG, servo throws, good linkages etc.

1 Like

Thank you, Tridge. How did you know the unbalanced parts of the plane just by looking at the flight logs? What parameter should we check?

I see significant integrator buildup in the PID logs, plus if you look at the AETR log message you’ll see unbalance in aileron and elevator usage.
Cheers, Tridge