Xuav Talon Crash

Hi Today i am flying my Xuav talon , running arduplane 4.2.2 latest, soon after take off the plane felt not stable and it tried going up but it felt bumpy , constantly pitching up and down and slowly .It was in a Auto mode following a small mission, but eventually it was making turns and crashed. During the final leg of crash, Error compass variance message came. Any inputs what led to the crash, might be helpful. Checked on the control surfaces post recovery all were intact. No Airspeed on this.
Log

Thank you

Without logs hard to determine what had caused the crash. Upload the logs please.

Hi
Log is uploaded via gdrive link under my message there is the Log highlighted please click on it . Posting the link also here .

https://drive.google.com/file/d/1eACN2EMMKNK1haRcvu0cP-mIcthP9JWn/view

Thank you

Your data logs does not contain any logs.
Duration of the flight is 1s, compass is fail to initiate, throttle didn’t go above 20%, never done any autotune,m.

Here’s my suggestions, in order:

  1. Set ARMING_CHECK,1. If you’re getting errors with this when you try to arm, then fix them.
  2. Fix the Centre of Gravity. I think that the C of G is too far aft. The continual pitch oscillations, coupled with large speed changes suggest the plane is out of trim. The plane came very close to stalling many times.
  3. Set SERVO_AUTO_TRIM,1
  4. Carry out an autotune.
  5. If possible try to set up current monitoring. Won’t solve this crash, but in the long run it makes it better for battery management and troubleshooting some compass issues.

A stalling porpoise. I wouldn’t suggest making any more Auto flights until you have this basically flying: