Originally Posted by Graybeard
Birgenair was different, because the lower ranked FO knew what was happening
..........DW: As did the PNF in this case, judging by the CVR.
GB: The FO could have overpowered Capt. by pushing harder on the yoke. Could he have done that with a joystick?
DW: If he'd called "I have control" and pressed the priority button, of course he could have. The issue for the Birgenair F/O, as it was for the AF447 PNF was that he wasn't assured enough of his assessment of the situation to take positive control and hold it.
GB: As for your argument that the 777 backdrive can fail: it's built to the same safety standards as the Cat IIIc autoland, i.e., 10 -(7?) probability of undetected failure.
DW: As are the Airbus systems, so why trust one system and not the other?
It's you who previously threw out the probability of a 777 backdrive failure rendering it no better than a joystick.
The 777 backdrive provides continuous feedback to the PNF of the commands by the PF and AP. And it is in the peripheral vision at all times, even while the PNF is attending the ECAM. The PNF doesn't have to focus on the EFIS to interpret the commands.
And you're wrong to equate a high ranking Capt on Birgenair to the AF 447 PNF copilot. The 447 PNF seemed to be less aware of PF actions, because
there was no yoke!