mm43
The following is a combination of FDR traces posted in a format used to convey the data that HazelNuts39 had originally constructed from the BEA's initial report on the FDR data.
Very interesting indeed.
Pay attention to the smoothed normal acceleration curve:
02:10:05 - 02:10:12, 7 seconds, load increase from 1,0 g to 1.4 g
02:10:12 - 02:10:40, 28 seconds, load decrease from 1.4 g to 0.8 g
02:10:40 - 02:10:55, 15 seconds, load increase from 0,8 g to 1.1 g
02:10:55 - 02:12:00, 65 seconds, load decrease from 1,1 g to 0.9 g
What the crew really felt despite their SS actions, was the initial overshooting in g in the first 7 seconds, then the correction phase for 28 seconds, then a increase again to 1,1 g in 15 seconds, followed by going below 1 g in the following 65 seconds.
Caught of guard by speed loss and AP/ATHR dropout combined with lack of training and stress might have increases the danger to follow the feel in the pants instead stick to the instruments, like we climbed too much, but now it feels like leveling.... even descending when below 1 g and do not disturb the cabin too much.....
Loose straps with impaired seating position (we do not know, wether the seatbelts of PF separated due to impact or if they had been donned inproperly). might have influenced the resistance to unload further. Best seen here also, that the erratic stick inputs of PF (after initial pitch) does not influence the big picture concerning g-loading that much. When we talk about too much backstick pressure after the initial pullup and compare it to the g loading, then the resulting aircraft response does not represent the SS inputs that clearly.
Talking about traces, the
post from lampaeso is an interesting compilation of traces with cockpit communication, thanks very much for that work.
What struck me most is the fact, that the pitch came down below the horizon in several timeframes, and mostly in combination not to SS pitch ND inputs, but to big bank angles to the right in combination with full oposite SS input and even SS full NU inputs.
02:11:55, 25° RH bank, SS full left, SS full NU, pitch -10°
02:12:10, 20° RH bank, SS full left, SS full NU, pitch -10°
02:12:50, 40° RH bank, SS full left, SS half NU, pitch - 5°
02:13:00, 40° RH bank, SS full left, SS half NU, pitch -5°
02:13:55, 30° RH bank, SS full left, SS full NU, pitch -5° (double input)
Watch also the stall warning and VVI during these occasions as well as the CVR.