the proper way to find the cg on a biplane

[doug9611]

what is the right way to find the cg on a biplane ?

[fhhuber]

Depends on what level of finding CG you mean.

If you know the measure from upper wing leading edge you pic 2 spots that far back and balance it on your fingertips.
The Staggerwing, with the lower wing leading edge forward of the upper, you do it inverted, supporting on the lower (now on top) wing.

To calculate the correct CG using the 25% to 30% MAC "rule" you use the airplane's shadow cast on the ground, not the total wing area. Just the part of the lower wing which can be seen from directly above counts for CG

[doug9611]

thanks fhhuber for the reply, I know the measurements but was not sure to check it on the top wing or the bottom wing and do I have the plane right side up or inverted, thanks again