Second crash from 15 m (hexacopter)

I have a problem when the flight mode change from automatic to manual , the Hexacopter stops engines and drops like a stone . Using Channel 5 ( aux ) using Futaba T8FG and receiver with sbus, Navio2 and raspberry pi3.

@Vicent_Mayans

It’d be nice to have flight logs, APM version and image version. Otherwise it’s extremely hard to tell what’s wrong.

Could you also elaborate on this one? Please, take a look at this footnote.

If I can´t use the chanels 5-8, how I change from auto to manual with the radio?

Here is the log
logs

My guess is simple, you changed the flight mode while your throttle stick was at lowest position.
In the log it is clearly visible that channel 3 is at 1000 while channel 5 changed …
Addionally, changing the flight mode failed. I suspect you were chosing a mode which depends on the GPS. However, there was no sat lock according to the log. So AP changed back to manual mode, and because you had no throttle it crashed.
This hapened once also to me with my robust test copter. Simple pilot mistake. Just take off in Loiter mode. Then the copter arms only with GPS lock.

I highly suggest you to avoid auto flight modes and overly expensive builds at the beginning, because you will crash in this phase.

Thank you very much for your help.
The problem is that I turned up the throtle but there was no reaction of the engines , it is as if they were unarmed .

It looked like the throttle was off the whole time according to the log. Nearly all controls where either mid stick or off.
I don’t know the reason for this, but maybe try not to start in guide mode, but manual to test your setup.