avionimc
I am concerned that the long term understanding of the QZ8501 accident will be, "They were just conducting unauthorized inflight troubleshooting."
That was definitely a factor in the accident of course, but we should never lose sight of the fact the loss was directly caused by a gross piloting failure.
The aircraft was actually capable of being controlled, but the improper crew reaction to the new configuration caused them to lose control. In this regard, the accident very closely resembles the AF447 accident.
Perhaps we need to be tracking an accident causal factor called, "Loss of Control-Unrecognized or Not Understood Control Configuration Change."