EMIT,
very insightful, and some interesting facts. Thanks a lot.
The deepest root cause of this accident may well be, the extremely slow acceleration of the engines from idle.
I do not quite follow you there. In a very deep causal analysis this may turn out to be a causal factor, but I rather think that the links between the engine properties via FADEC control laws via the changed MEL procedures via confusion to neglecting to retard a thrust lever are too weak to stand the Counterfactual Test.
1. (fact) The A-320's IAE engines accelerate very slowly from idle.
Do the CFM engines accelerate significantly faster? I thought slow spin-up was inherent in all gas turbines. (Evident also in the tubo lag in turbocharged piston engines.)
Slow spin-up from idle was a causal factor in the Habsheim accident.
All the discussion so far has been about points 8 and 9. Very interesting by themselves, but only scratching the surface.
There has been quite some discussion that the changed MEL procedures (points 5 and 6) might have added to the confusion, although the reason for the changes in the procedures were unknown.
In the discussion about point 8, I want to state clearly, but at this moment I have no time to elaborate on it further - the autothrust system with non-moving thrust levers is well thought out and logical, but it is NOT NATURAL!
Perhaps not, but then again, what is natural in controlling complex machines? As I pointed out, though, the operation of the levers may be considered natural: accelerate: push, cruise: leave alone, stop: pull.
Incidentally, same as with moving levers.
Bernd