Gavin wrote: "The reduction in vortex drag between a single taper and elliptic planform stab would be incredibly small. Far too small to be noticable. You also start running the risk of tip stalling the stabs, especially with a V-Tail which is used for rudder as well. High Aspect Ratio is a good thing for stabs." That was all good advice except for the misleading last sentence. I think what Gavin was trying to say was that a higher AR stab is more efficient, which is true. But there is a limit to how high you should go with the stab AR. The aspect ratio of any tail surface should have a lower aspect ratio than that of the wing. It appears that using a stab AR at least 10 percent lower than the wing AR is about the upper limit for stab AR. I would say that going to 25 or 50 percent lower AR for the stab is safer yet. There is a trade off with stab AR. Yes, higher stab AR is more efficient, but it is also more sensitive to deflection and will stall earlier than a lower AR stab of equal area (assuming the airfoils are the same). A plane intended for more aerobatic use or high G turning may need a lower AR stab compared to a TD aircraft. So to qualify what Gavin said, use the highest stab AR that is appropriate for your aircraft configuration and intended use. Martin Brungard Tallahassee, FL "Meandering to a different drummer" PS: The info above only applies to conventional tail aircraft, not canards. ________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com RCSE-List facilities provided by Model Airplane News. Send "subscribe" and "unsubscribe" requests to [EMAIL PROTECTED]
