With respect to induced drag and down wash it should be noted that induced drag is lessened when the aircraft in in ground effect. The down wash (from the wing) on the horizontal tail surface is less and this requires more elevator back force as the airplane enters ground effect, in order to maintain a given pitch.
There is a characteristic up wash ahead of the wing followed by a down wash behind the wing. These up and down washes are in a sense 'flattened out' as the airfoil enters ground effect.
