By mentioning that 99% accidents are avoidable, I mean that 1% are the result of chain of events that are either unforeseen or considered to be " To remote to be considered ,financially
Take for example: An incident where in the Pax on he emerg exit wanted to check if he could open the Emerg Exit on Ground before Take off...
or An Extremist or terror activity
I accept your point, Sir. Such things you mention are examined in a risk assessment process. For example, in a geologically stable country, the risk of earthquake may well be discounted and result in buildings that do not have earthquake protection being constructed. However, if one lived on the San Andreas fault, to leave this out would be tantamount to negligence.
However, certainly of the two examples you give one is not an accident as I would define it. Terrorist or enemy action is an 'on purpose'. Your second example (I am not familiar with modern ac systems) I would have thought could be overcome with a simple interlock system if it is a risk.
The point I was trying to make is that if you start with the premise that 'accidents are inevitable' you are starting from the wrong point.
Believe me, all accidents are avoidable.