Wing Thin-Walled BoX Lift Top cover panels are compressed .Buckling stress f(t/b)2 thickness t Wing box weight Cover weight min Rib total weight many rew ribs ribsWing Thin-Walled Box Lift •Top cover panels are compressed b thickness t •Buckling stress = f(t/b)2 many b Rib total weight min few Cover weight Wing box weight ribs ribs