I'm just finishing up an AT-6 scratchbuild, and since its very light, I am confident that my little
OS .10 will pull the 40" span model.

The problem is, the little engine leaves a huge gaping mouth to catch the air, and I was
thinking of filling in at least the bottom half.

I was thinking this would cut down on overall fuselage drag, but how would this affect prop
efficiency with a flat surface right behind ?

Also, this is a handlaunch model, so I'd sure like to fill in that space so it doesnt scoop up dirt.