Tail plane in ground effect during rotation.

[XPMorten]

Linton,

I might misunderstand you, but I really don't understand your reference to Downwash in a Ground Effect context.

The reason you get a drag reduction is;
The LATERAL flow of air (along the wing axis, not longitudal like downwash) towards the wing tip
due to pressure difference below and above the wing will get slower. This is due to the space of movement gets smaller closer to ground.
THIS FLOW is the same flow that creates wingtip vortex -
or better known as DRAG.
So, e.g an aircraft with WINGLETS will get less drag reduction than one without...

Now, when getting into the Chord effect, as you know there is a lift increase due to RAM pressure. Whenever you have an
increase in lift, you will have an increase in INDUCED DRAG. Again, downwash is not an issue..

Cheers,

M