I hate when "investigators"
resort to "Human Factors"
to explain a "complex failure interaction".
But maybe sometimes there are such HF's.
We all recall the AA901 / 26June94 MD11 upset ntsb's id
MIA94FA169
(co-pilo
t NOT seated in a "normal position",
with seat-aft, &
legs-crossed heel-to-knee). Electric seat, visitor entered cockpit ... .
That's ONE red-flag for students of inflight upsets.
The
other red-flag mentioned :
Visitor-in-Cockpit (F/A).
Several pilots have mentioned PAX ethics (keep their seat-belt fastened)
Pilot-lessons : Cockpit Housekeeping
--
AA311 / 8Oct1947, DC-4, NC90432, Chuck Sisto upset,
taught us that cockpit occupants can unexpectedly interact with switches on the overhead panel (feathered engines).
Housekeeping, Pilot Ethics, "airmanship" from 2009