Pixhawk Misbehavior at midflight

Quadcopter specifications are-

  • Pixhawk 2.4.8
  • 1000kV Motors
  • Simonk 30A ESCs
  • Ublox M8N GPS
    We used v4.0.2 quadcopter firmware.
    Our quadcopter was flying nicely for about 2 minutes in the loiter mode and suddenly it went out of control and crashed. We completely lost control. I have attached the log file and the video drive link below. After this crash, we again calibrated accel, compass, and radio. On the next flight, we used Altitude Hold mode. The quadcopter was flying nicely below the knee level, and as soon we tried to bring it above the knee level, the throttle went to max and the quadcopter was completely out of control. We had to disconnect the battery to stop the motors. Unfortunately, we don’t have the log file and of this crash.
    To reduce the vibrations, we had used hitlon sheet.

Any help appreciated.
Crash 1
LOG file

RC1 & 2 are at minimum throughout several portions of your flight, so I would guess severe imbalance maybe, and then when you go out of control they are all over the place. So I would suspect mechnical failure of some description. Your vibes are too high regardless.

Thanks for pointing out some issue. Can you suggest us some remedies to this issue?

Also, if you see the altitude in BARO, there was a negative spike and after that the errors started. And in POWR, there was some voltage drop after which the spike was observed. Can this also cause the misbehaviour?