Sassy, how long ago was the AN-2 designed? And the 3-winger was 1917 wasn't it? I recall a video of a plane with a wing like a venetian blind, it got to about 4 knots and it folded up, like a ... well, like a venetian blind.
Why doesn't Boeing or Airbus make biplanes, if they are still considered to be a worthwhile idea?