> Temporary inconsistency between the measured speeds, likely as a result of the obstruction of the pitot tubes by ice crystals, caused autopilot disconnection and [flight control mode] reconfiguration to "alternate law (ALT)".
- The crew made inappropriate control inputs that destabilized the flight path.
- The crew failed to follow appropriate procedure for loss of displayed airspeed information.
- The crew were late in identifying and correcting the deviation from the flight path.
- The crew lacked understanding of the approach to stall.
- The crew failed to recognize the aircraft had stalled, and consequently did not make inputs that would have made recovering from the stall possible.
Quoting your link, "Final Report" section:
> Temporary inconsistency between the measured speeds, likely as a result of the obstruction of the pitot tubes by ice crystals, caused autopilot disconnection and [flight control mode] reconfiguration to "alternate law (ALT)".
- The crew made inappropriate control inputs that destabilized the flight path.
- The crew failed to follow appropriate procedure for loss of displayed airspeed information.
- The crew were late in identifying and correcting the deviation from the flight path.
- The crew lacked understanding of the approach to stall.
- The crew failed to recognize the aircraft had stalled, and consequently did not make inputs that would have made recovering from the stall possible.
Note the numerous "the crew"