Wedge
It seems that you have a greater grasp of the detail of this than I do. You have made a strong statement about Peter Neilsen's part in the accident - I wonder if you would share the detail of his mistakes? Could it in any way be argued that his mistakes were provoked by the situation he was in?
What I find incredible is that (as I understand it) he was required to be monitoring 2 radar screens, 20 yards apart by himself. Surely, that is an unacceptable situation for any ATCO to be put in and it ought not to get through the safety case?
As far as the management is concerned, it seems to me that they willingly removed a number of the safety nets in order to get essential work done without first providing mitigation of the increased risks. That action directly exposed the system and Mr Neilsen. Regardless of what other errors were made, that strikes me as negligent.
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