... a fully-stressed beam. A derivation is given here.Wing Weight Breakdown DC- 8- 5 5 DC-1 0-1 0 STOL StudyWing Bending Material 13,115 21 ,83 0 5, 983 Wing Spars, Webs, Stiffeners2,301 2 ,82 2 1,136Bending, ... 24,652 7,119Ribs 1,463 2,333 82 5Wing Box Weight 22,7 18 33,623 10, 387 Total Wing Weight 33,604 49,2 98 20 ,86 1Bending / Total . 387 .443 . 287 Box / Total .676 . 682 .4 98 Detailed Wing Weight Buildup ... Subtract 8. 5% for all-cargo aircraft. 5. Landing GearGear weight is about 4.0% of the take-off weight. This is the total landing gear weight including structure, actuating system, and the...