Gums, that was a very interesting publication you linked to, thanks.
This passage jumped out to me:
The traditional approach to stall training consisted in a controlled deceleration to the Stall Warning, followed by a power recovery with minimum altitude loss.
Experience shows that if the pilot is determined to maintain the altitude, this procedure may lead to the stall.
A practical exercise done in flight in DIRECT LAW on an A340-600 and well reproduced in the simulator consists in performing a low alti- tude level flight deceleration at idle until the SW is triggered, and then to push the THR levers to TOGA while continuing to pull on the stick in order to maintain the altitude.
The results of such a manoeuvre are:
- In clean configuration, even if the pilot reacts immediately to the SW by commanding TOGA, when the thrust actually reaches TOGA (20 seconds later), the aircraft stalls.
- In approach configuration, if the pilot reacts immediately to the SW, the aircraft reaches AoA stall -2°.
- In approach configuration, if the pilot reacts with a delay of 2 sec- onds to the SW, the aircraft stalls.
This shows that increasing the thrust at the SW in order to increase the speed and hence to decrease the AOA is not the proper reaction in many cases (this will be developed in the following chapter).
In addition, it is to be noticed that, at high altitude, the effect of the thrust increase on the speed rise is very slow, so that the phenomenom described above for the clean configuration is exacerbated.