He's trying to argue that because mcas moves in increments rather than a single continual application that it would not be considered a runway trim situation.
No, the argument is not the incremental activation but the fact, that it stopped immediately by applying manual trim on the yoke. --> Stopped automatic trim ≠ trim runaway.
1 Control column. . . . . . . . . . . . . . . . . Hold firmly
2 Autopilot (if engaged) . . . . . . . . . . . . .Disengage
Do not re-engage the autopilot.
Control airplane pitch attitude manually with
control column and main electric trim as
3 If the runaway stops:CHECKLIST COMPLETED
4 If the runaway continues:
STAB TRIM CUTOUT
switches (both) . . . . . . . . . . . . . . . . CUTOUT
That right there says to cut the switches when the manual trim failed to stop the stab from moving again. Just because it took several seconds to be reactivated means nothing.
I have added the "Checklist completed"
line item after point 3, that you conveniently left away. It means that in the large majority of the MCAS trim cycles, the pilots did follow this memory item checklist and did 100% comply with it:
1. The trim started moving
2. The autopilot was disengaged, and they controlled the airplane manually with the control column and the main electric trim as needed
3. The runaway stopped -> "checklist completed"
On the following picture the relevant events are extracted:
(1) These are the manual main electric trim inputs (mainly nose up)
(2) These are the MCAS induced nose down trim inputs
(3) Totally 23 times (21 in a row) the runaway stabilizer checklist was done with line item 3 after the runaway stopped -> "checklist completed"
(4) This was the first full MCAS cycle, that went without manual interruption. At that point they stood with one foot in the grave. But during the next MCAS cycle the manual input that stopped the MCAS input was there already, so even during that final time going through the above checklist has ended at line item 3 -> "checklist completed"
. Then another MCAS cycle was triggered, that was unopposed, so the stabilizer finally stopped at the full nose down position and the aircraft was unrecoverable.
So statements like "they were not flying" or "they did not follow known procedures" at max could made about the two unopposed MCAS cycles at the end. The rest was flying to the textbook, fully compliying with the NNC. In fact, if you run the NNC stubbornly to the end, you will never reach line item 4. The runaway always stops, when trimming manually. So every time, sticking strictly to the NNC would mean -> "checklist completed"
at line item 3. In a sense, the pilots of the flight before did not follow the NNC as accurate, because they missed, that using manual electric trim the MCAS would stop.
You also have to remember, how humans work. If you do something 21 times and each time you find the trim to stop immediately after you give manual opposite trim, your mind must have come to the conclusion, that trim runaway is not your problem.
(5) And there is this one: during the time, when the first full uninterrupted MCAS passed by, the plane seems to have started a turn (see heading change). And during turns it is bad practice to trim. Applying pitch trim during a turn means, that after the turn you end up in an unpredictable trim state. So my theory is, that as during the turns trim input is not done at all or only sparsely, the MCAS was able to do its two full, deadly cycles.