Re: Air France Flight 447 accident
"What amazes me is that Airbus pitots don't have automatic sensors to turn on the heaters under icing conditions."
Now you got a sensor ON a sensor. And that sensor can still fail.
"Or that it didn't use inertial/GPS nav input as well as the mechanical airspeed inputs (there are a number of ways of estimating speed sans pitots and pilots are taught them. This should be part of the flight control program too)"
Which doesn't help much if you're getting conflicting readings, meaning one sensor says one thing while another says a different thing. At this point, it can't figure out which one's the right one and having additional sensors isn't likely to help since you can always have a failure cascade that makes multiple sensor say the same WRONG thing at the same time.