WHERE is the AP/FD vertical engagement mode trace ???
That trace would tell if the 'zipper' is irrelevant.
In the meantime that trace is central to figure what were commanding the FDs when displayed.
Why such trace is missing ?
Isn't the difference between V/S and V/S selected equal to the FD order?
They are both in the same trace.
V/S mode is active from 02:10:26 and on.
FD bars displayed when FG considers 2 or more speeds valid and consistent.
The first 10 sec. after FD comes available the bars are flashing dim/bright.
Max. limit is at 6000ft/min and actual limit is set by Vsw/Vmo
when available. (meaning FD bars will not direct one into Vsw/Vmo)
Don't know the exact resolution as displayed on PFD and Vsw/Vmo were available at the moment FD bars were in view.
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The PNF saw as much blue as PF, BEA and ACARS don't report any CHK ATT message/flag displayed, so FWC considered both attitude signals in agreement.