aguadalte - an even more confusing post! It has got gyros - it hasn't got gyros - it has got gyros.....
If I may divert momentarily, it is important here to differentiate between a gyroscope, which is a rate sensor, and a rate sensor (eg QRS or LRG), which is NOT a gyroscope. A gyroscope will maintain its attitude in a space frame and thus enable 'attitude' to be directly physically determined. A rate sensor, as in ISIS, can only offer displacement information FROM a known attitude, and requires a lot of software to produce the new 'attitude'. It lacks the vital 'rigidity' which the gyroscope has.
Back to 447 - I'm still not clear if we have an answer to what the software would have shut down or permitted in the way of information to the crew. Have we established BEYOND DOUBT that loss of pressure inputs to an ADIRU render that ADIRU unusable for attitude, either because it lacks some feed or because the system determines it to be 'unusable'? If the answer is yes, then we move on the the John Wayne scenario where the good captain is holding a torch in his clenched teeth and shining it on his only remaining attitude indicator. Does this definitely still function, or has HAL decided it too should be shut down because it has either faulty attitude inputs from the ADIRUs or faulty pressure inputs? I've been searching for info on the Qantas and Air Caribe 'upsets' to see what they 'lost' on the panel - anyone point me please?
Even with a better understanding of the systems, we are still basically in the dark as to what the software programmes are doing.
If breakup of the airframe did indeed occur, we really should be going BACK to how it got to that position in the first place, rather than discussing flat spins, VS failure modes etc. We need those recorders!