Originally Posted by
tae9141
I read a phrase from B737 FCTM and it says as below:-
"The leading edge devices ensure that the inboard wing stalls before the outboard wing."
Is this because of how inboard lead egde flap is situated or is it different theory that supports aforementioned idea?
While we tend to think of a wing stalling at a single AOA value, usually the stall begins in one area and spreads to other regions as the AOA is increased. It is desirable to have the stall begin in areas away from the roll control devices (usually the wing root) so lateral control can be maintained approaching and even into the the stall. That said, the stall characteristics of a clean wing can be significantly different than when in the landing configuration, particularly with swept-wing aircraft which have a tendency to stall at the wing tips. Leading (and trailing) edge devices changes the effective camber and chord line of the wing, and the amount of this change can vary along the cross section from wing root to tip. Effective design of these devices, sometimes with the addition of vortex generators, will ensure that roll authority is retained in the landing configuration in inadvertent high-AOA situations (e.g. windshear).