Gents,
I"ve had a bug to build a flapless, long moment flying stab design for awhile, but never acted on it.  Does anyone have any wisdom regarding wing:stab area, stab airfoil, pivot point placement (% stab chord to pivot point)?
Thanks,
Les Byrd

Bob's Cherokee is the best example of a stunter with a flying stab I've seen.  The fuse is wide enough at the back for a decently wide hinge and the stab extends behind the fuse, making it stronger and better aligned.  Flys very well too.

Hinging at 25% of chord is the absolute max.  That essentially makes the stab float around it's mean aerodynamic chord with very little control feel.  A little further forward hinge point, 18-20% will give more control feel.

The biggest advantage for a stabilator is that you don't run out of control if the plane is slightly noseheavy.  A flapless plane can easily be trimmed to handle a wide range of CG positions and still have a decent control feel.  A standard stab/elevator combo can only generate so much lift with the elevator moved to 25 deg. or so.  Any more elevator movement just generates drag.  If you need a little more turn with a stabilator you can just crank in a few more degrees of travel, up to about 30 deg.  As the plane turns the angle of attack of the fuse gets subtracted from the angle of the stabilator, so 30 deg. of stabilator travel can drive the wing up to about 15 deg(where it stalls), but since the stabilator is less highly loaded than the wing it doesn't stall.  On a full flapped plane you will probably have to limit the stabilator travel to around 15 deg. since the flap movement limits how much angle of attack the fuse develops.