Pixhawk crash after switched flight mode

I have a problem which has twice led to crash of my multirotor. In both cases this happened when switching flight mode. A few days ago I created mission in MP and flew, immediately after take-off, I switch to auto mode. Because I made a mistake in planning, I soon switched to stabilize flight mode. I adjusted the height of the flight, and then re-enters the auto flight mode and then it crashed. I attach log file of this flight. Please help me in determining the reason for the crash. Im using pixhawk 2.4.8 with firmware 3.3.3
2016-09-25 17-20-07.bin (756 KB)

Hi Silvo,

to me it looks like a mechanical failure.

When you switched to auto mode RCOUT4 was working harder than the other outputs.
When you switched into auto mode the second time vibrations became very high.

It might have been Motor / ESC on channel 4 that was fading away ?


It does look like a mechanical failure, as @Linus stated.
Both 4 and 3 RCout were pegged at max.
Also vibrations went very high at that point. Could you have shed a prop?

Have you checked the operation of all your motors and esc’s since the crash?

No not yet because Im waiting for spare parts (one arm broken). Strange to me is that when I reviewed the log with APM Planner 2, I noticed that all motors immediately after switching to Auto mode for a few moments stopped. Also it happened to me once before, and then everything worked without problems.