B737 Flaps 40 question
 

Does anyone know why I always seem to get into some sort of lateral PIO when landing F40.
I read somewhere that an extra roll spoiler unlocks with F40 vs F30.

Over controlling. With F40 roll control becomes more effective.

No, the airflow gets bent. Spoiler deployment starts at a different angle of roll input.

Zero spoiler input is shifted 1.5 degrees of roll towards one wing.

B737-800 with Flap 40: what causes increased roll sensitivity? [Archive] - PPRuNe Forums

Try mixing the configurations more often, you'll soon get used to it