infrequentflyer789 - a quick look only, and I'll come back with more time to your queries, but just to say that I am trying to isolate HF here - there were obviously big issues in that department - but am looking primarily at how crews can/should be notified when a system which is at the heart of the protections built into an aircraft has malfunctioned such that the protections are not there. This purely as a pilot now - my 'engineering days' are well behind me.
Again leaving HF aside, it has been argued that the RadAlt #1 failure on the AMS 737 should have been more readily flagged to the crew - the 'subtle' inference of the failure was not appreciated by many 737 operators. This may, of course, have been addressed by changes in emphasis during training. As said above, we do not know what was or was not 'flagged' to the AF 447 crew.
I am more on the sliderule side of things
- I still take my slide rule out of its dusty box occasionally and AMAZE my sons and grandchildren - "you did what?!!!"
