APM 2.6 Crash log analysis

Hi all

I have no idea how does the multicopter crash.
When executing RTL, the multicopter start to tilt in a dangerous angle and then flip&crash
I had tested these modes: manual/althold/loiter/auto, and RTL function.
It works fine more than 5 flights. And I think it is stable.

I’ve posted the detail to the following link
Any help will be very appreciated !!


This graph is derived from Mission Planner “Log Browser”. Maybe there is something wrong with the motors.

Besides, I found that the similar case by the following link
copter.ardupilot.com/wiki/common … sing-logs/
It says that the actual curve and the desired curve mismatch is caused by mechanical failures.

thanks all the people who like multicopters