OH I SEE. SO A HIGH WING PLANE WOULD USE ANHEDRAL?? THIS WOULD PUT THE TIPS AT ENGINE CENTER LINE>>>>???? "NOT"..ITS JUST NOT THE CRITICAL..TLAR WORKS JUST FINE..FORMULAS ARE OK ,BUT NOT THE FINAL WORD.. IF THEY WERE,THERE WOULD BE NO NEED FOR WIND TUNNELS, OR TEST PILOTS.A BUICK TRUNK LID WILL FLY ,IF YOU MOVE IT FAST ENOUGH.FOMULAS ARE JOB SECURETY FOR GUYS WHO CANT BUILD, OR FLY.. RD