This post is to retract my earlier assessment that the initial response from PF may have been wrong. After spending a couple of days studying the report, I'm not sure anymore. It is unfortunate that BEA has released so little factual information. There is very little to go by. I'll just post some questions I scribbled in the margins of the report here before taking leave and waiting for the July report.
From 2 h 10 min 05 (4), the autopilot then auto-thrust disengaged and the PF said "I have the controls". The airplane began to roll to the right and the PF made a left nose-up input.
Why nose-up. Was this required to arrest the roll to the right?
The PF made nose-down control inputs and alternately left and right roll inputs. The vertical speed, which had reached 7,000 ft/min, dropped to 700 ft/min and the roll varied between 12 degrees right and 10 degrees left.
Propensity to roll right again?
The airplane was subject to roll oscillations that sometimes reached 40 degrees.
Were these oscillations symmetric? These oscillations correspond to a sharp turn to the right on the track shown by BEA in figure. Again reasonable to assume a/c wanted to roll right? Why?
Edit: remove nose-up comment.
The a/c seems to show a propensity to roll right from AP disconnect to end of flight, why?
My conclusion, there is more here than meets the eye. There is just not enough factual information to explain the oddness. There are enough doubts in my mind now to say the initial response of the PF was wrong.
Peace.
Last edited by CogSim; 29th May 2011 at 21:00.