Originally Posted by
scifi
Hi Conso, I think you are looking at the wrong end of the incident.. The error occurred 2 1/2 to 3 minutes before the take-off roll.
The left AoA Sensor starts to give erroneous data during the taxi run, maybe caused by strong tail-winds bashing the AoA Vane in the wrong direction.
From that point on, until 8 1/2 minutes later the flight was not viable.
However,
pilots and aviation experts say that what happened on the Lion Air flight doesn’t look like a standard stabilizer runaway, because that is defined as continuous uncommanded movement of the tail.On the accident flight, the tail movement wasn’t continuous; the pilots were able to counter the nose-down movement multiple times.In addition, the MCAS altered the control column response to the stabilizer movement. Pulling back on the column normally interrupts any stabilizer nose-down movement, but with MCAS operating that control column function was disabled. These differences certainly could have confused the Lion Air pilots as to what was going on.Since MCAS was supposed to activate only in extreme circumstances far outside the normal flight envelope, Boeing decided that 737 pilots needed no extra training on the system — and indeed that they didn’t even need to know about it. It was not mentioned in their flight manuals.
from sunday seattle times article-
Substitute HAL for MCAS - ' I'm sorry dave- I cannot allow . . .'