Bruce.....

You are misunderstanding.

I have already measured the wing area, and if I subtract out the area involved in the fuselage, and then just the area underneath the wing when at dihedral (NOT flat), then my estimate and that shown on the plan coincides near exactly. This sort of like the older Wakefield rubber powered formulae.

Is this typical of Russian designs?

The other Russian A/C that I have do not an area cited on the plan.

Wm.