is there a guideline for optimizing flight based on where the engine/propeller is placed along the vertical axis? some planes have the propellers well below the wings, some on the wings, some above the wings.
i've been reading about center of mass, center of lift, center of pressure, and center of thrust, and none of these seem to address this.
is there any sort of "center of drag" concept? so like if i'm quickly pulling a plane horizontally through the air on a string, the point of string attachment where the wings will be level to the ground? eg if i had a plane with a very tall fuselage that was completely under the wings, and attached the propellers to the wings, i'm assuming the plane would have a tendency to nose-dive due all the drag pushing against the front of the fuselage under the propeller/(thrust vector). ?
namely, will the bottom 2 planes, below, have a tendency to lurch forward/downward because of this (unlike the top plane)? something that would have to be counteracted by the tail and be less efficient because of it?