[danielvf]

When anything in a 737 moves the stabilizers, physical wheels in the cockpit loudly turn right next to the pilots. In the case of a stabilizer runaway, it's really obvious. (See https://www.youtube.com/watch?v=3pPRuFHR1co&t=154)

MCAS is just one of many different systems on a 737 that can automatically adjust the stabilizer. Because there are so many things that could be the cause of the problem, the checklist procedure for any runaway is just to cutout automatic control of the stabilizers.

Here is Boeing official update to all 737 MAX operators after the crash, which boils down to saying "follow the checklist, dummies".

http://www.avioesemusicas.com/wp-content/uploads/2018/10/TBC...

[lolc]

Thanks. So that blaring and the wheels turning is what we assume happened 24 times in that cockpit before the crash?

If I understand this right the pilots must have known the plane did adjust stabilizers, but they didn't have a way of finding out why it did it. And per checklist they shouldn't have cared for the why, but just cut-out the automatic control.