How do you ascertain that? The traditional answer is performance attitudes (which we see a lot of in postings) but an aeroplane can be approaching a stall in a normal takeoff/climb attitude for many reasons, such as: strong adverse wind gradient, temperature inversion (often combined with the item before), incorrect loading, wrong flap setting, incorrect performance data and/or incorrect FMC weight/speed entries. If you leap straight into the UAS checklist at that moment, what will happen if you really *are* on the stick shake? I never tried this in the 737 sim but my gut feeling is that isn't a good place to be: on the back of the drag curve, keeping the nose high and likely take a bit of power off... Hmmm.
Good question. How indeed?
For a moment or two after rotation when the stickshaker and stall warning burst out you are doubtless momentarily and firmly in the land of half-crown, threepenny bit, dustbin lid. But within a very short period of time you see TOGA thrust confirmed, airspeed/groundspeed confirmed, attitude correct and your sphincter begins to relax the dustbin lid to manageable proportions; then you see the usual huge Boeing ROC and realise the thing is flying as normal and thus the warnings
must be false and the laundry-threatening event is all but over. The mere fact you're not mushing along the runway at thirty feet and 20' pitch in ground effect should tell you this. IMMEDIATELY.
Then you
know the next thing to do is AIRSPEED UNRELIABLE chex. - What else fer chrissakes? WHAT tf ELSE???
If you don't - in the sim - you've just failed that check. Bombed it.
That's why we train these events in the sim, so we learn to recognise them and know better than to repeat them on the line.
I know I won't be thanked for it but it appears to me that these crews hadn't left this lesson behind in the sim.
Why?
Well, that's quite another matter...and one I suspect will become the crux of investigation in the months to come.
There can be little doubt that merely carrying out AIRSPEED UNRELIABLE chex would have pevented these accidents altogether.
(as would a number of other fundamental vital/airmanship actions too)
The more I think about this the more I see this as a training/culture/airmanship/professionalism/HF failure than anything else.
That's not to exonerate Boeing by any means, but when all else is said and done all 4 pilots had it entirely within their power and ostensibly within their training (tbc) to avoid both these accidents regardless of what the airplane seems to have done. In neither case did the airplane begin the event in anything approaching an unflyable condition, but just as in AF 447 the pilots very quickly and unnecessarily managed to put it in one through gross mishandling.