Crash when activate autotune

ArduCopter Copter 4.0
1

Previously we had a homemade quadcopter flight, which had a crash. And the broken and non-functional parts were replaced.
but the Pixhawk controller stuck around for no drawbacks.
This topic refers to a second flight carried out today (10/20/2020), when the flight begins it remains stable but at moment autotune is activated, it begins to lose altitude, without responding to the radio control until it crashes with a fence.
Now we take out the log of the pixhawk, and while it was downloading, we noticed that the pixhawk started to respond badly. We have decided to change the part, but we do not know what has happened, so we leave the Log of the flight to have a more experienced opinion.

Thanks for your time, and sorry my rusty English.

2020-10-20 16-38-42.bin (812 KB) .

2

You seem to try Autotune in Stabilize mode (seems not easy), so have to move sticks constantly:

2020-10-20 16-38-42
2020-10-20 16-38-423440×775 162 KB

Try in PosHold, Loiter or AltHod. You can start Autotune at low altitude and check again, perhaps reducing aggressiveness.

3

Please do read the instructions before doing autotune !!!