I have spent 60 years plus in aviation as a pilot and only had one
pitot tube fail to give me airspeed (a wasp had entered). Attitude
reference (real or artificial horizon) takes over to control the aircraft.
Pitot tubes when heated, as most of them are, are extremely reliable
and I suspect that Thales (in the case of AF447) may have made changes
to accomodate computer sensor pick-up etc.thus complicating it with more
chances of something failing.
Normally you burn yourself badly when touching a heated pitot tube and icing it would be next to impossible.
Accuracy of airspeed? If you ever flew in realy turbulent conditions, you
would not question a decimal difference, leave alone plus or minus
10-15 kn as can happen in mountain flying and rotors.
So my conclusion is : don't re-design the wheel, unless you are building
a sled !
