This should be made clear during ground school, in that the aeroplane manufacturer knows their aeroplane. This means if the QRH calls for a resets without caveats, the pilot should do as per the QRH and NOT try to outthink the system. I know this goes against the grain for those used to the "old" way of doing things but design has moved on.
This brings up an interesting point: If it is
-not- in the QRH what then?
Reports suggest that the Lion air crews (both flights) might have been trying to find a match for their situation in the QRH and other manuals. The third pilot on first flight ultimately suggested the trim motor cutouts, not clear if this was before or after he got the large book from his carry on.
One theory is that some crews are trained/held to tight observance of SOP and any actions outside of those are strongly discouraged. This is good as long as the SOP can cover every eventuality, which of course they cannot.
Is it possible the Lion air accident crew did not follow the trim runaway procedure since it was not an exact match for what they were seeing and/or were afraid of consequences if they did and it was later deemed to be not following SOP?
Could this fear have influenced how the prior crew wrote up the incident?
Point being that system knowledge can be vital for undocumented cases, in addition to knowing the procedures understanding what they do and possible side effects is important since it allows problem solving in situations -not- in QRH or other sources.
In the Lion air MCAS case knowing for sure that the cutout switches would work
-and- confidence that they could manage the aircraft after they were used might have saved the day.
Really too early to extend to Ethiopian case since not known (to public at least) how similar the cause(s) were.