1. Mark the centerline of each flange of each rib and rib assembly.
2. Insert ribs into skin. Flanges of basic rib (nothing attached to them) should point inboard. Insert control arm rib assembly into inboard end of aileron, and a left and right counterbalance rib assembly on the outboard end. Counterbalance arms are orientated to face each other. Align centerline of flange with holes in skin and transfer drill holes into rib. Before drilling counter balance ribs, mount the counter balance weights or a temporary spacer between arms as shown below.
CAUTION! The counter balance weights can be easily damaged because the lead is soft so use care when handling them. Please use appropriate safety gear when handling, sanding or drilling lead at all times. (Gloves, safety glasses and a respirator)
3. Trim and bend flanges of aileron skin as necessary to obtain a tight fit. The tighter the fit, the better the aileron will look. A loose fit when riveted will cause the skin to bulge between the ribs.
