Drilled LH wing tank attach angles using "Chekoway Method". For all but the inboard angle I drilled a #12 hole in one of the flanges on the lengthwise centerline and 1/16 inch toward the flange from the widthwise centerline. I then bolted the angle in place on the spar through the single center hole, squared it up and clamped it in place. Then I drilled one of the outside holes and put another bolt in that hole, removed the clamp and drilled the final hole. I then drilled and countersunk the holes for the nut plate attach rivets in the outboard angle.
