Hello to all,

Again HAPPY NEW YEAR 2003 !!!!!!

To Grob... of course, biplane rigs seem theoretically very very interesting, by dividing aerodynamic loads by 2 on each rig, at SAME ASPECT RATIO, you lower the CoE by 20% or more and cracks the induced drag ( in theory ) by 2 also...BUT, practically, things come a little bit tougher...

First, because of Munk's wings stagger theorem, you see interference drags between 2 ( if lateral gap is under 30% rigs span ).

Secondly, broad reaching in light to medium airs could suffer severely when the AWA is near 90° ( acceleration process ) from the "shadow effect" of the windward towards the leeward rig...

Thirdly, structure becomes quite complicated with diagonal internal shrouds, compression connection beam somewhere in the heights, spi attachment mess...shroud limiting course of battens due to crossing backstays... EXCEPT, self-sustained masts strongly set up in carbon dwells inside hulls...that's rather hard to manage.

May be, with new fibers such as Akzo M5, M40J carbon or Boron's Silicates, one day, you could set up the rig so simply that even a Laser will seem you a 505 !!!!

Friendly Yours,
Frenchie