Thanks flash2002, for providing some more info. Now, does anyone know when and where did the serious incident happen? Just curious who is investigating.
From the scant data available, it seems we are dealing with simultaneous identical failure of three independent sensors. There is extremelly slim chance the simple (no matter how aerodynamically sophisticated is its blade) swiveling AoA vane can be frozen solid by external icing. It might get unbalanced, it might start reading erroneously but to get the bearing frozen solid, significant moisture must be present at the base, below the aeroplane's skin.
If had to place my bet now, I'd put my money on Perpignan-style washing.
Originally Posted by flash2002
Switching off those 3 ADR's could have been a major problem, making things worse.
Oh, sure. If they switched off ADRs following problems with AoA and then followed erroneous AoA information while cheerfully ignoring their attitude then they would be in real trouble.
the BUSS, fly the attitude!
Originally Posted by flash2002
12 degrees nosedown is NOT ACCEPTABLE!
It resulted in how many deaths? Injuries? How much damage to property?
Now I have your attention, I'm not saying it is acceptable (whatever criteria we might use to define it) just that it was recoverable.
Originally Posted by 737Jock
having to turn off ADR's is not normal!
Maybe that's why we call it "Abnormal"?