Scheprock
A direct lift control is one that enables the pilot (or autopilot) to vary the lift at constant pitch attitude. It has the advantage that the controls do not have to fight the pitch inertia to get an attitude change to make the AOA change. (A potentially big advantage with a high mass aircraft)
The normal way such systems are arranged is that they reduce lift by using a spoiler type of surface. If this system is partially deployed at the start of an approach then by waggling the spoilers a tad in and out from this mid position you control lift directly.
Or you could wave the ailerons (symmetrically of course) up and down together to get the same effect of a lift variation at constant AOA. The notion was much in favour before the likes of the 747 came along as designers worried about the difficulty of quickly changing pitch attitude on such “monsters”. In fact pilots did not find it too hard so long as they got the approach “stabilised” well out. (In other words did not have to vary the lift close in!)
Any help?
JF