Originally Posted by
spornrad
Then, in desperation, they probably switched on the electric motors again, only to find out now, with two very short trim-up switch attempts, that in the meantime, electric trim quit working too (speed has meanwhile increased further). A nightmare.
If you look carefully at the FDR traces it seems to me that the electric trim did in fact work after apparently re-enabling it. The line goes up ever so slightly around 5:43:15, just before MCAS trims nose-down again. About back to where it was when the trim cutout switches were set to cutout.
I wonder, since the next page (27) has much higher-resolution graphs of some parameters, why the graph showing the flight control parameters (p. 26) is only low-resolution (looks like a screenshot).
The scenario painted on
Bjorn's corner at Leeham News seems very plausible and extremely scary, especially the take on why only short trim blips were used. One of the most scary parts is that even at a moderately out-of-trim situation, where the PF could hold the control column forces for several minutes, that mechanical trim would not work, if that turns out to be true.
Bernd