From the examples above:-
Weak auto thrust design, the system could go to sleep; the designer was surprised.
Weak FD switching logic, mandated use of FD for takeoff; the operator was surprised.
Multiple probe icing beyond the conditions assumed by regulation; the regulator was surprised
Okay, the above anomalies occurred, but the in each case the aircrew made some woeful errors that actually caused the accident/incident:
- No attempt to monitor the airspeed during the approach into SFO
- Blindly following the FD during take-off without looking out of the window (or again, monitoring their airspeed!)
- Continuing to maintain a pitch-up input despite the obvious clues!