Originally Posted by
henra
???
What plausible scenarios does that leave?
=> Stall as initiating event rather unlikely (too much speed margin, flight attitude pretty stable and straight, albeit hefty ND with rather lowish AoA in the footage)
=> Out of Trim situation somewhat unlikely if the position of the jackscrew represents the state it was in during the terminal phase of the flight.
=> failed jackscrew/ball nut can't be completely ruled out but is not really support by the picture of the jackscrew nor the apparent started recovery => rather unlikely.
At the moment I'm somewhat at a loss what could have reasonably caused that loss of Control.
Some instrument failure causing false and highly unexpected aircraft attitude data beeing displayed for the pilots making them push hard on the yoke, aka CRJ200 crash in Sweden....
Failure of the elevator control/servo system putting the aircraft in a steep dive, aka 737 rudder hardover......
Mechanical breakage/failure of the HS screw jack system including its attachment structure making the HS freefloating, somewhat similar to Alaska MD-80......
........