For my PT-20, I marked  a centerline on the edge and a bevel-to line on the top and bottom of <div>the elevator and used a 10" GP bar sander. I used the GP countour sander on the leading edge </div><div>of the horizontal stab. I think fighter jets have sharp leading edges to stop <span style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">shock wave formation </span></div><div><span style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">from destroying lift. </span></div>