1. Does a biplane have twice the lift of a comparable single wing plane (assuming th same wing length). For instance, a biplane with a modified clark y airfoil will have a certain wing area and related lift. If you removed one of the wings, would you loose half of the lift.
2. Secondly, if you built a single wing plane with the same type of wing with the same wing area as the biplane, would you have more lift?
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Reply:
Because of this interplane interference if you remove one wing the other will actually recover some lost lift so if you remove 1/2 the area you'll actually only remove about 1/3 the lift.

It's a rule of thumb that a biplane with twice the wing area of a monoplane only has about 1.5 times the EFFECTIVE area. But this IS only a rule of thumb. The actual percentage of relative efficiency depends on that interplane distance and the stagger effects and other stuff. But a biplane will never be as efficient at producing lift as the same area monoplane. And it will always produce more drag than the equivalent area monoplane even if you ignore the extra support structure drag.
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With this reply in mind, does that mean that you should calculate the wing loading for a biplane differently than for a single wing plane? Should you multiply the normal calculation by some factor (1.2 -1.5) to get an "effective" wing loading?

These questions are all related to my winter project - Beechcraft Staggerwing. I'm am building this model from Sid Morgan Plans and can't find anyone who has built and flown this model. The plane is a 64 inch wing span with 1200 square inches for both upper and lower wings (3 degrees positive incidence) 187 sq. in horizontal stab (2 degrees negative), will weigh about 12 - 15 lbs, and powered by an OS 1.2 four stroke (2.5 degrees down thrust). The air foil is a thin modified Clark-Y.

Since I can't find any real world reference for this kit/model, I am trying to "scientifically" determine how she will fly.

3. Most importantly, should I use the decalage stated above which for the full scale airplane? Should the decalage be modified for a model? The Royal kit Staggerwing has all surfaces at zero incidence.

This is a long message but very important to me.
Thanks,
Vic