Originally Posted by
Fl1ingfrog
Very muddled language creeping in here, back to basics. Thrust and drag = pitch up, Lift and weight = pitch down. The lift weight couple dominates the thrust/ drag couple. The Horizontal stabiliser provides a down force providing a pitch up moment. The Trim tab is used to vary the down force of the horizontal stabiliser. Increase the thrust and the aircraft pitches up (thrust can also be gained from the speed by diving which will cause a pitch up also). So, increase the thrust and the nose pitches up aided by the increase in drag, then lift/weight opposes the pitch up but not completely. Any increase in speed will be a pitch up moment aided by drag. A initial large increase in pitch may be observed if thrust is added rapidly. As the forces stabilise the pitch up will settle downwards but not to the original attitude.
So if power is used to fly out of the stall then any pitch up will deepen the stall and therefore must be opposed by pitch down elevator. If you do not have any elevator pitch down force remaining then it will not be possible to stop an increase in the angle of attack. Thus the advice to reduce power (thrust) is to reduce the pitch up forces "if necessary".
100%
There have been many accidents and incidents where applying TOGA power with lots of nose-up trim caused a loss of control. Classic case: very slow on approach for x reasons, go-around on TOGA power, uncontrollable pitch-up. Well, uncontrollable without reducing power and/or getting on the trim fast.