Originally Posted by
Concours77
It is inconceivable this system was not challenged during test with loss of/compromised AoA, to elicit this very behaviour.
Inconceivable, but clearly they did not know. Because if they knew, and the system was approved, somebody got some splainin’ to do.
FAA:
This AD was prompted by analysis performed by the manufacturer showing that if an erroneously high single angle of attack (AOA) sensor input is received by the flight control system, there is a potential for repeated nose-down trim commands of the horizontal stabilizer. We are issuing this AD to address this potential resulting nose-down trim, which could cause the flight crew to have difficulty controlling the airplane, and lead to excessive nose-down attitude, significant altitude loss, and possible impact with terrain....
Erm, other than that, what’s for supper...?
So does open up another possible explanation for the Fly Dubai Rostov on Don crew? I think the interim report was suggesting over enthusiastic use of the stab trim by the PF with fatigue coupled with the rather inplausible 'I forgot I was still holding the trim switch' type of argument. So easy to blame a fatigued crew eh? Like shooting ducks in a barrel.!!.