Originally Posted by
phylosocopter
ahh as soon as to AP disconnects, the craft will start to roll! some intervention is required to keep wings level after AP disconnect.
my question is , were they at that point (immediately after AP disconnect) seeing a raw gyro attitude display or were they seeing some flight director telling them to go up?
My view is that BOTH the manufacturer and the regulator should be facing questions here because the state of alarms and displays at time of unreliable airspeed is not defined in regulation (as far as I can see)
edit.... have now found this discussion of the accident report that answers some of my question at
https://www.ainonline.com/aviation-n...pitch-commands"A major new finding in the final report concerned the flight director, which normally displays symbology on the pilots’ primary flying displays that give guidance on control inputs to reach a desired steady-state flightpath. After the autopilot and autothrottle disengaged, as the flight control law switched from normal to alternate, the flight director’s crossbars disappeared. But they then reappeared several times. Every time they were visible, they prompted pitch-up inputs by the PF, investigators determined. It took them a long time to “rebuild” what the flight director displayed since this is not part of the data recorded by the flight data recorder.The BEA acknowledged that the PF might have followed flight director indications. This was not the right thing to do in a stall but it seems that the crew never realized that the aircraft was in a stall. Moreover, the successive disappearance and reappearance of the crossbars reinforced this false impression, the investigators suggested. For the crew, this could have suggested their information was valid.None of the pilots recognized that the flight director was changing from one mode to another because they were just too busy. The PF may have trusted the flight director so much that he was verbally agreeing to the other pilot’s pitch-down instructions, while still actually pitching up.The BEA’s report includes significant recommendations about the flight director. One of them calls for European Aviation Safety Agency to review its “display logic.” The flight director should disappear or present “appropriate orders” in a stall."
from
IIRC, one of the UAS procedures is to turn off the FD.
As an aside, the auto-pilot could probably be programmed these days to cope with a UAS event without disconnecting.