DC-8, you made your points, some of them I could follow, but over time your repetitions get a bit boring, sorry to say.
Several posters here have stated that in Direct Law, the plane flies just like it's non-FBW predecessors but obviously the pilots of this aircraft were unable to do so.
I think that's the main point. No reversion back from "auto" thinking to "manual" action.
- They entered a stage where they expected to see the kick-in of several protections.
- I assume they did never realise the completely back trimmed elevator - as this is no item to care for during normal ops, which they were used to.
- I assume the complete lack of protections and automation struck them in a situation they were unable to break that barrier of mind because of the huge workload kept them occupied (see sidestick action).
- They obviously never used the trim wheel manually during that flight, which seems to could have saved the flight.
The preliminary report suggests that 9 minutes before impact there was deliberate manipulation on the flight laws, not covered by the test procedure. Then the crew expected at that "stall test" in 3000' a fully functioning A/C, which it wasn't. The broken AOA disabled some auto functions. They could not break that and didn't make use of all items the A/C provided them to regain control.
Never make any "quick and dirty testing"... And that's exactly what the high altitude serves for in a "real" test flight: gain reaction time.