Organfreak
The significant Pan Am flight numbers were PA217 (1968), PA816 (1971), PA806 (1974), PA812 (1974). A series of reports was produced by Pan Am and the FAA detailing the major problems with the airline but these were kept confidential. I would hesitate to use the word blame though. As PJ2 points out blame is a legal concept and a bit out of place. Of course like everyone I have been guilty of using value loaded terms like this because it is often easier to write. It is not a matter of blame as such but an inability to cope with the situation in hand. I detail what I think was missing but I do not believe that the aircraft was a factor in this. One can argue that if things have been different in design or warning features then the accident would haven't have happened. Unfortunately this is what I would characterise as a wish state. Other accidents have demonstrated that where these features were present they didn't necessarily prevent an accident. The question why comes down to the people flying the aircraft and their background. To try and evade that and attribute the accident to a machine fault is to my mind dangerous as it assumes that we can further design the pilot out of the loop.