Two of the most alarming accidents that involved pre-programmed back trim (system input) during a coupled approach and a subsequent missed approach, both involved in a very short space of time, either the A300 or the A310.
I am going back to the 90's and when I get some time I will find the references (apologies that I am not able to do that at the moment) but it should be relatively easy to find the accident reports.
First one: Nagoya.
Second one: Taipei (Chang Kei Shek as it was at the time).
PIC unable to overcome the pitch trim input following a Manual AP disconnect during the Missed Approach before the aircraft(s) stalled.
I remember seeing both unfortunate wreckages. Plan form on the ground.
I will give you more when I have the time; apologies.