How does aspect ration compare between a bi and mono wing?
How about drag for engine selection?
Effects of dihedreal on lower or upper wing or both?
Thanks , Ace

An eyeball look at some airplanes designed for RC aerobatics can be seen here -

http://www.rcuniverse.com/showthread...82&forumid=232

and

http://www.rcuniverse.com/showthread...44&forumid=232

and

http://www.rcuniverse.com/showthread...71&forumid=232

Compare them to the standard F3A airplane and you find the wings are a little smaller, thinner and there are two of them on the same fuselage. The same aspect ratios, etc are there.

Dihedral on a bipe works the same as dihedral on a monoplane. The presence of the upper wing causes a dihedral effect and putting anhedral into the upper wing has been done. It looks funny so most designers don't do it. The engine for total wing area requirements are about the same I think. Considering the range of engines that are put on standard monoplanes (depending on the use of the airplane) the engines used on bipes are not all that much different.

I do know some of the visitors to this forum have had experience designing bipes so they should give some input..

I like to use one size bigger engine than you would expect for two reasons. one, to cempensate for the extra drag of a bipe and two, most bipes are built for aerobatics where the extra power helps. Flat top wing and a bit of dihedral in the bottom wing makes for neutral stability.
Ben. Still trying to get my pictures up but got as far as [ save to] and don't know where to go from there. To old to go to computer school!!

On biplanes, the airflow around one wing interferes with the airflow around the other. One effect is that that the top wing, usually ahead of the lower, directs air downward which reduces the effective angle of incidence of the lower wing. Bipes are usually designed with a couple degrees more incidence on the lower wing relative to the top wing. Another effect of the airflow interference is an increase in drag, and reduction of lift. Instead of relying on actual total wing area, one should consider 83% of actual wing area to be the effective wing area. This means the effective wing loading of a bipe is higher than what would be calculated based on actual total area. More power is good, if the loading does not get too high . High loading on a bipe means a glide like a brick.

If the biplane is to be used for aerobatics I would suggest both wings the same area, same 0 deg incidence, and no stagger. It will fly the same up as down that way. Puttering around in a scale Waco or the like will benefit from what lowandslow mentioned (puttering, lowandslow - pun intended but failing)