What brought about the distinct change in design philosophy that has seen airliners that routinely use the outboard ailerons to augment flap function? Examples: 777, A330/340, MD11. The use of inboard ailerons only in the same manner - as on the 767, for example - was seen a bit earlier. And, going still farther back in time, no other major jets ever used any of the ailerons (inboard or outboard) in the same way (e.g. 707, 727, DC-10, L1011, 747).
Does having the entire wing trailing edge as "one flap", even if in sections, allow you to use fewer degrees of deflection overall, thus increasing lift while decreasing drag? Is that the whole point?
As a counterexample, consider the KC-135 wing. The flaps have a large deflection, while the ailerons do not perform any flap augmentation: this causes there to be simultaneous sections of high-lift, and other sections of perfectly clean wing.
Would love to read some thoughts on this whole thing.