My process keeps all the covering the ARF came with intact! Having said that I’ve never had the Covering a ARF came with last more than 10hr of air time. Bill insisted that he could make it last and has painstakingly cared for his P-51D’s covering and is now getting to the point were he admits it could use a recovering on the bottom of the wing. If you look at the pic’s of Bills H9 P-51D you can pick out the overlap of the covering we put over the LE of the flaps and the TE of the wing. On the top of the wing we matched it with appropriate colors but on the bottom we left the silver overlap the d-day stripes.

While on the subject of D-Day stripes the actual aircraft modeled by this ARF did not have the D-Day stripes on the top of the wing so I’m debating weather to remove them from the top wing or not. I probably wont, opting to get as meny flights as possible on this plane before a recover is needed.

To do split flaps find the TE structural members in from the wheel well. Notice which way the grain goes in the vertical member. If it goes span wise (structural) or top sheeting to bottom sheeting (Shear webbing), next notice if it goes through the ribs (structural) or stops at the ribs (shear webbing). If it is shear webbing we can remove that with impunity because what we will replace it with will more than make up for it! But there could still be a structural member behind the shear web. There are a number of ways to verify what is behind the shear webbing, the easiest is to use a push pin. You know the shear web will be 1/16, 3/32 thick so if you push the pin in just behind it, it should go right through. Or even put the push pin in a pair of pliers and push it through the shear webbing if a good feel can be gotten from that. But I know that the punky balsa I will be removing from the flap area will have to be stiffened up for flap use and the easiest way to accomplish that is to replace it with ply. That makes that sheeting expendable so I would lay out my scale flaps on the bottom of the wing then lay out the shear webbing over the flaps and cut a x-acto hole in the expendable sheeting to look at the back of the shear webbing for structural members. When doing this remember to make the hole big enough to see things well. Pic's here would be very helpfull to all others thinking of doing this with the same manufacturers plane.

If there are structural members behind the shear webbing, is it balsa or a hard wood? If hard wood that means the member is expected to carry considerable stress. The way ARF's are built I'd bet nothing is behind the shear webs so the first test I would try is to push on the shear web from the wheel well. Now the ball is in your court.