Drone takeoff automatically & irregular descent

[etiennepixhawk]

Hi

I have 3 identical drone with pixhawk, at the factory settings and one of them, when I arm my engines in position mode, takes off alone. Is there a parameter for this?

And when the drone lands, it is difficult to detect the ground, so it takes off automatically after a few seconds ...
I have to re calibrate the sensors and I can not find the right parameters on Q ground control...

Thanks.

Etienne

 

[pyrate]

get mission planner, and yes do all your calibrations before taking off