D6-27370-MAX-TBCNFF
According to the "Flight Crew Operations Manual Bulletin" D6-27370-MAX-TBCNFF:
"It is possible for the stabilizer to reach the nose down limit unless the system inputs are counteracted completely by pilot trim inputs and both STAB TRIM CUTOUT switches are moved to CUTOUT. "
The bulletin also says that an AoA failure could automatically disable the autopilot, which then could and probably would activate MCAS.
So the flight takes off, and at about 1100ft, an AoA fault shuts off autopilot, the stick shaker rattles the left yoke, and MCAS trims nose down, as designed.
Do audible stall warnings sound?
The pilot instinctively pulls back and trims, but MCAS re-engages after 5 seconds, as designed.
The pilot pulls the yoke to adjust pitch (and forgetting that MCAS could be engaged) before calling to circle back.
The first officer may have even suggested flipping both STAB TRIM CUTOUT switches - assuming he was a good FO - and he read the bulletin.
The pilot attempts to steady the craft using yoke only - because he already compensated for potential runaway trim, right? And what does a green FO know.
The only way to save the flight is by flipping both STAB TRIM CUTOUT switches. But the pilot really needs to return the stab to neutral before flipping the switches to avoid the need to find the trim wheel handle, flip it out, and hand crank it back into place without the motors - which would take too much time (minutes) anyway.
For a good pilot, this procedure might seem routine. But even good pilots have bad days. One faulty AoA sensor can disable autopilot, initialize MCAS, override manual pilot trim, and screw the stab to a full down position. This is clearly a design flaw, even if there is a procedure to mitigate it.