My Align 450 flybar is running Copter V4.0.5 on Pixhack 2.8.4. During flight test on Pos Hold, the heli suddenly lost power and descended to ground with slight damage.
Recently I am testing the Pos Hold / Loiter mode in which the heli does not hold in position tightly, but drifts a little bit. RTL also did not perform satisfactorily. This sudden loss of power has happened for the third time.
Please help to review the attached log to trouble shoot the cause. Parameters are also attached for reference.
Thanks for help.