First of all, let me introduce my quad configuration and the crash details.
We have a Tarot T960 hexacopter configuration based on a APM 2.6. We have tested many times and it flies really stable.
This morning, we decided to do the first flight of a modification based on this frame, but in this case, just with 4 arms, in quad configuration. The controller in this flight test was a pixhawk with APM 3.2 version.
We were testing loiter mode in order to measure the time autonomy with a new battery ( Multistar 10000maH). It was stable and after 3 minutes of flight, something happened and drone fell free and crashed.
I have downloaded the log, but after analysing it, I can not figure what happened and which was the problem.
Please I need your help in order to determine which problems we had in order to not commit the same mistakes.
* I recorded the crash, so I will update the topic with the link of the video. Probably it helps in the analysis.
*I have attached the log file.