Will, I use Wiki a lot, but not for basic aerodynamics. 5 years studying for an Aero Eng Degree and practicing a wee bit afterwards means I don't need to...
The predominant effect of le devices is to extend the lift curve slope,
The predominant effect of flaps is to give a Delta Cl increment (with varying degrees of Delea Cd, becoming very significant at full flap positions)
I
was indeed talking
slotted le devices, but even if not slotted on the 747, the le camber has a similar effect, the predominant one (Wiki has it right) to extend lift curve slope (to higher alphas), since without the le camber, flow breakdown will occur earlier - but yes, an extension and camber will give a delta Cl increment as well.
So in actual fact for the 747 we're both right
As pointed out above, the pilot flying was doing a great job right on the edge of a cliff, between the devil and the dep blue sea, having a very narrow margin of operational alpha until he could dump some drag and pickup a few knots here and a few there...
Another Sully, making simple, basic, and most importantly quick decisions! He won't get to retire and write a book though...
