How to find (CG) of biplane
with positive stagger and
both wings swept back

Tall Paul has a method that I find quite elegant and at least as usefull as any I've seen.

You look down on a top view and treat the portions of the wing that you can SEE as one wing. So obviously that would be the whole top wing and whatever shows of the bottom wing added onto the top shape. Now do your MAC geometry for this imaginary wing and from that select your CG based on the tail volume coefficient.

That is problem. How do you find

(MAC) of a swiptback wing

Also what is tail volumn coeffieicent?

Thanks for your help.

I sort of thought those two would be next...

Either you or I can do the search. Since you need to read them anyway I suggest you go play with the search function. It's a common pair of topics and excellent answers are waiting for you.

Come on back if you get really stuck.

http://www.rcuniverse.com/forum/m_86.../tm.htm#861355

Search box at the top is broke... just gets you a search on { } (nothing) but access to the search page by hitting the "Search" in the corner at the top of the results.

Limit the search to the aerodynamics forum and search on "Finding MAC" and the page this is on will pop up in the list just a few from the top.