Best L/D and most efficient AOA

[Piltdown Man]

Ignore the engine. It is irrelavent. What counts is the wing and the way it works. Flying just above the stall you will have a high angle of attack and high drag. As you lower the nose and increase airspeed, the angle of attack will reduce and the drag will reduce. Keep lowering the nose. You will keep increasing speed but the total drag will continue to reduce until you get to minimum drag speed. Keep increasing reducing the AofA and increasing airspeed and you will arrive at best Lift/Drag ratio. And further reduction AofA will result in more speed and drag. At speeds below minimum drag, the greatest proportion of total drag is induced drag as the wing worked "hard" (moving fewer air molecules a greater distance). At speeds above minimum drag where the wing worked less hard (where many air molecules were forced to do a small amount of work) the greatest contributor to total drag was parasitic.

In each case above the lift remained constant. One variable changed, the AofA. That in turn reduced a specific airspeed and drag value.

Eckhard: Many wings generate life at a negative angle of attack. Also, rather unfortunately we rarely know the actual (average) AofA; we are not given that rather useful value. But we can be assured that the wing's angle of incidence will be calculated to give the best body angle/AofA/handling compromise.

PM