Hello all,

I have a flying wing that I am setting up. The wing is about 30 years old and I have no idea where the CG should be. Is there a general rule of thumb I could use to get this plane balanced before flying it?

Thanks!

What is the shape?
Plank, swept, delta?
These have different requirements.

The simplest way is to build a simple cardboard hand-launched glider with the scale planform. A simple flat plate airfoil and 6" wingspan is fine. It should have some dihedral, and a small amount of "up" elevon or elevator, produced by bending the cardboard. I often check out unusual planforms this way, just as a quick check of my CG calculations, and often find that the simple glider that takes about five minutes to throw together gives more accurate results. I use various numbers and locations of paper clip noseweights, test gliding until I get a good stable glide at just above stall airspeed, then record the CG position works best.

Start at about 18% of the m.a.c. and go from there.
I think I said that right.
Also see post no. 2

generally it wants to be just slightly infront of the thickest part of the wing