Quadcopter with Pixhawk randomly crashes

I’m new to quadcopters and my copter randomly crashes while flying. I set it in autopilot mode and I think one motor suddenly stops working or slows down then causing the other motors to try and correct it, but it loses altitude until it hits the ground.

My setup is:
Tarot 650
hobbywing skywalker quattro 20A ESC
380kv tiger motor

I have a log file of the crash also which I will upload.

I’m pretty much brand new to these things so I’m not totally sure which info to give you guys.
Just let me know if you need more information and I’ll try to get it to you.
Any help is appreciated.

I’m probably not the best at analyzing logs, but for the most part everything looks fairly healthy. Maybe someone more tuned in could look at the magnetic values. There are some peaks of about 300, I think during manual stab manipulation. But I would expect more consistent problems from the beginning if it were that.

Near the end one of the motors on channel 4 went to zero for a while, perhaps in response to an opposite motor mechanically/electrically failing temporarily.

I notice you switched to Loiter and put throttle to full to try to straighten out the problem. Loiter throttle is much less responsive. The ideal response to any problem in auto modes is to switch to Stabilize. There you should have full control. At least if there is a failing motor, your input responses will be more “certain”.

Other notes. You should check your parameters and assure that they are ideal for your copter. You are using 4S batteries, but have failsafe voltage at 10.5 for instance, something like 14 would be better. Also you have Battery failsafe turned off. Perhaps your choice, but it will help you prolong the life of your batteries and avoid unexpected failure of your copter at 100 m alt.

So suspect perhaps intermittent motor failure, either mechanical or electrical. Motor 2?

Anyone else?