Ethiopian airliner down in Africa

[Albino]

Originally Posted by Takwis

Here are the memory items for "Runaway Stabilizer":

I. Runaway Stabilizer

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 needed
   If the Runaway Continues
3. STAB TRIM CUTOUT SWITCHES (both) - CUTOUT
4. If the Runaway Continues
5. STABILIZER TRIM WHEEL - GRASP and HOLD

Since the condition before step three says, "If the Runaway Continues", I would infer that at that point the aircraft is no longer in trim. Could you identify for me which subsequent step would put it back into trim?
It is looking very likely that moving the trim wheel with the trim set too far nose down is not physically possible, especially at high airspeed. As a last desperate measure, they tried something that wasn't in the checklist.

Step 2 - Control airplane pitch attitude manually with control column and main electric trim as needed.

Was this step done? 2 units is nowhere near in trim and significant control column input would've been needed. Full stabilizer authority was available to the pilots using the electric trim.

If runaway continues... I'd argue people are getting hooked up on semantics here. You can't put a long winded paragraph in covering every eventuality. The system is still not performing as expected so you cut out the stabs, ensuring step 2 is complete and the aircraft is in trim.

The bulletin Boeing sent to all operators and should have been read by all pilots was very clear on this point in 'Operating Instructions'.