Originally Posted by Cool Guys
I am an electrical engineer with considerable experience in highly automated equipment that can kill people when things go wrong. Hence I am highly interested in these discussions about the plane’s automation. I have very limited flying experience.
I am a software engineer with experience in the development of life-critical software systems including healthcare patient diagnosis, and command & control systems. I'm also an aviation enthusiast, so I am highly interested in these discussions as well.
I think your post was spot on with regard to the lack of sound HCI principles in the design of the autopilot system. If this kind of automation is going to be in place, it should not completely crumble upon the loss of one input parameter (albeit a very important one).
The flight computer is aware of the weight, the altitude, the AOA, the last indicated reliable airspeed, and almost everything else the pilot will use to perform his own calculations to decide on the best course of action. If the autopilot just hands over control as it did in this situation, and the PF is supposed to go 85% N1 and 5% AOA (or whatever it is), then I think the autopilot should do that for him, and just display a very big warning. The pilot always has the option to disconnect the autopilot if it starts doing something stupid, this would at least give them more time to think and react.
Heck, can't the autopilot even handle stall recovery? It had the vertical speed parameter intact and it knew AOA, thrust settings, elevator position, trim, as well as weight etc. so it should be able to preempt a stall even without knowing airspeed. Am I wrong? I'm tempted to write the code for that and send it to Airbus, though most of it probably already exists in flight simulator software.