Originally Posted by
meleagertoo
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.
So. Imagine for some reason you’ve cocked up the performance calculation and/or entered the wrong weights in the FMC, like
EK407, maybe even not as grossly. What are you going to see? Thrust - what you intended, airspeed - as bugged, attitude - somewhere in the takeoff range. Nothing *obviously* wrong? Given differing density altitudes, runway parameters, terrain constraints, variable flap settings, ATM & fixed derates, etc. there is no “one size fits all” measure of performance these days. In a FBW aircraft, any “feel” in the controls will be based on false data.
Then you know the next thing to do is AIRSPEED UNRELIABLE chex. - What else fer chrissakes? WHAT tf ELSE???
If the crew on the
BA56 had dismissed the stall warning as false, things would most likely not have gone well from then on. They had no indication that anything was amiss but they respected the stick shaker.
JK5022 is what can happen when you ignore a stall warning at low-level.
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.
You could also say that you are training a single response to something that is much more nuanced in reality. Yes, you can pass the sim but fail dramatically in real life...