Originally Posted by bearfoil
They do say, however, that the a/c was slow to respond to PF's climb input. "At PITCH +10, the a/c began to climb."
They didn't quite say that, but it may be a literal interpretation of what they wrote in the Update. I have a slightly different interpretation that I would like to throw up for debate. As I read it, one investigator has listened to the CVR and notes the words spoken at 2:10:16 and 2:10:50. Another investigator has studied the DFDR data and gives an account of various observations he has made between 2:10:05 and 2:10:51. He places those observations in a 'logical' order, more or less but not necessarily exactly in the correct time-sequence. For example:
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.
Was the nose-down input before or after V/S reached 7,000 ft/min? The reason I'm raising this is not that sentence, but the preceding one:
The airplane’s pitch attitude increased progressively beyond 10 degrees and the plane started to climb.
I don't believe these two events occurred in that sequence. If they had, the airplane would be in level flight with pitch at 10 degrees and therefore AoA 10 degrees. At M=0.8 stall warning begins at 4.2 degrees, alpha-max is 5.25 degrees, and the airplane stalls at about 8 degrees. Furthermore, pitch angle does not jump instantaneously from the initial 2.5 degrees to 10 degrees. As soon as pitch angle starts to increase 'progressively', AoA and hence lift increases also, and the airplane starts to climb (give or take small g-variations due to 'chop'). Just can't wait for the real DFDR traces to look for myself ...