Originally Posted by
737 Driver
I had the exact same question when I first read the accident report. I spent a lot of time looking for evidence that the trim motor stalled or the trim switch wasn't working. However, none of the accident evidence or any historical data supports either of these conclusions.
One of the most telling pieces of evidence in this report, however, is that the Captain repeatedly tried to engage the automation (three times) in a situation that specifically precluded it. This is evidence of someone with a strong case of automation dependency. People with significant automation dependency also demonstrate a deterioration in basic hand-flying skills. Combine that with the startle effect and the distraction of the active stick shaker, it is entirely conceivable that the Captain suffered from cognitive overload and simply forgot to trim because it had never become a thoroughly engrained behavior.
Four times.
Take a look at 05:43:15, just after they made those two insufficient trim inputs. They got a warning there from a failed attempt to engage the autopilot.
Unfortunately the report has left out plenty of what was said and done in that last phase when they lost control.