[richardkmichael]

Yes, I point out AF447 as a perfect and horrific example of a problem which is really HCI (human computer interaction) / UX.

The lack of stall warning meant two different things: "not stalling", and "stalling so extremely it can't be sure, so don't report it"; as you say. I wondered if there should be a different sounding alarm for "can't determine". Or, the pitch of stall alarm could rise, such that pilots could tell "which side of the stall" the plane is on, so that entering stall from one side would side start with a very high pitch or very low pitch. (I'd guess there's a better way..)

So, in this case, it's more subtlety more tragic than you describe, because the pilot did correct the AoA, and nose down, but when he did that, the stall warning resumed (albeit from the extreme other "side" of the interval), confusing him: no alarm, alarm resumes, so he thought he "re-stalled" it and he pulled up again. This kept him mentally "stuck" in the extreme stall. They needed to "pass right through" the stall warning window, and come out the other side. They had sufficient altitude for this to succeed.