How many hull-loss accidents have NOT been solved as a result of unusable/unrecoverable flight recorders? It can't be more than 5. So hand-wringing about sensors is pretty much pointless if the actual goal is flight safety. The introduction of CVRs and FDRs has increased airline safety by an order of magnitude - only another order of magnitude improvement would justify changing the whole system. I think good training with emphasis on flying skills is much more important than obsessing over recorders and sensors. I get the strong feeling that the bad man of AF447 is the flight management system and the over-reliance on automation to fly the airplane.