Flaps on approach
I seem to remember that the drag goes up with the square of the lift. If you double lift, the drag goes up four times. Triple lift and the drag goes up NINE times. So the more flap you use, the more lift you produce but the drag goes up quite a bit (with the square of lift). During turbulent approaches, if flap is reduced, drag is also reduced, speed is increased and that helps to improve approach and go-around performance if required.
I well remember the L1011 that crashed going into Dallas years ago. Got into a microburst and couldn't maintain the flight profile. It's possible that a reduction of flap may have saved the day.
T