Originally Posted by
MemberBerry
Actually that's probably what happened to the Lion Air accident flight, not to the Ethiopian flight. There was not much trimming done on the Ethiopian flight, but on the Lion Air accident flight they did a lot of trimming while fighting MCAS. And the control column forces recorded by the DFDR seem to indicate that the Lion Air captain handed over control to the FO shortly before they lost control.
In addition to the change in pilot electric trim inputs (from frequent to infrequent), the DFDR traces also appear to show a brief, but marked divergence in the control forces exerted between the left and right side control columns. Normally there is a small variance with the pilot flying side showing more force than the non-flying pilot (which is how we can intuit when the change in control took place). At first there was a question raised whether this could have been a mechanical issue, but since that issue has not come forth in any of the Boeing/FAA/EASA discussions, then it is suggestive of inadvertent control interference. We have evidence that the Captain handed control to the FO in order to refer to a manual. It was suggested by another poster awhile back that if the Captain was reaching for his manual (usually stored in a pubs bag to the left and behind), his right leg may have drifted in front of the control column and thus interfered with an aggressive pull by the FO when MCAS activated. Throw in the sudden shock of the Captain being kneecapped into the mix (Captain shouts, FO releases back pressure, nose drops, etc), it may have contributed to the ultimate loss of control. Unfortunately, we don't have a full CVR transcript that might illuminate what exactly transpired.