PPRuNe Forums - View Single Post - B737 Upset Recovery nose low high AoB
View Single Post
Old 4th Nov 2020, 21:42
  #5 (permalink)  
Join Date: Dec 2002
Location: UK
Posts: 2,292
The general design and certification principles would normally require an increase in stick force to minimise over-stressing the aircraft ('g' wt), similarly for higher speeds (Q).

The PLI is related to the stall margin defined by AoA, not solely at slow speeds but also at higher speeds with applied 'g'; PLI could be shown during a high speed / high 'g' turn (spiral dive).

Thus for a spiral dive recovery, levelling the wings should provide greater stall margin as 'g' is reduced - PLI moves up / disappears. With further pull up the speed could reduce, reducing the stall margin; thus PLI appears / repositions on the pitch scale - respect the PLI.
A dynamic situation involving speed, 'g', attitude and above all else AoA.
Beware rolling 'g', do not trim into a turn.
safetypee is online now