>I thought a stab has to pull DOWN, not lift (or if you >want: lift "down") in order ot counteract the tendency >of the wing to roll-over ?
The stab on a typical RC glider with a good CG location can lift either up or down, but only slightly. In particular, the stab's Cl is rarely outside the range -0.05 ... +0.05, so the stab airfoil camber, as long as it's small, doesn't matter all that much. Note: Smallish stabs will typically have a very slight download (negative Cl). Largish stabs will typically have of very slight upload (positive Cl). Jerry uses rather large stabs, so his slight positive camber actually makes some aerodynamic sense. - Mark RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
