2018/3/11 Challenges in Landing Gear Design 圈上声文大学 Tasks and Objectives in Landing Gear Design 国上清大学 Attachment fitting adapted to the A/C structure ·Tasks: Geometry Adapted Min.ove ral din vith the L/G in the up to the aircraft -Requirements analysis Adapted tire retraction path -Integration with aircraft and configuration C.G.location) -Weight and loads,shock absorber Optimized Loads On landing -Kinematics(retraction and deployment) And Performance On rolling During retraction and extension -Cost Analysis Design Objectives and Constraints Required static strength -Minimum weight Dimensions -Maximum component strength High reliability Optimized ·Safety Low cost Operation 。Reliability -Overall aircraft integration Airfield compatibility Reduced Overall Cou High op ating endurance Easy maintenance More Detailed Description of Tasks 圈上活大坐 Historical Data 国上活大等 Type (tricycle,tail gear,bicycle,etc) Fixed(faired,or un-faired),or retractable,partially B:-J818W retractable 8 ·Height B7888N8 Wheel base 6%7 Wheel track 0.0500 The distance between main gear and c.g. Strut diameter 0.040 Tire sizing (diameter,width) Landing gear compartment (retracted) ·Load on each strut 3% GD Ean (d eRoskam'sreri Design Weighs Vo 00200 TOGW Ratio of la eagaea2-w58 _f/M96SC.html Landing Gear Arrangements 国上洋大峰 Landing Gear Selection vs Aircraft Weight 园上海发大坐 启三点式，touchdownspeed<12okm/h Aireraft Weight Landing Gear Selection sailplane B52 Four wheel Quadricycle 400000t 81436kg ngle main ge 250000b. 11398kg Two main wheel per strut/four B47 A380 150000b 68038kg wheel bogey Multi-bogey ain wheel 50000b 22680kg 满三点式，240一28okm/h Single main neel per strut 22018/3/11 2 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics, 2017-2018 Challenges in Landing Gear Design Geometry Adapted to the aircraft Optimized Loads And Performance Optimized Dimensions Optimized Operation Reduced Overall Cost • Attachment fitting adapted to the A/C structure • Min. overall dimension with the L/G in the up position • Adapted tire retraction path • On landing • On rolling • During retraction and extension • Required static strength • High service life (fatigue) • Low weight (% of the A/C weight) • Safety • Reliability • Simple design • High operating endurance • Easy maintenance © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics, 2017-2018 Tasks and Objectives in Landing Gear Design • Tasks: – Requirements analysis – Integration with aircraft and configuration ( C.G. location) – Weight and loads, shock absorber – Kinematics (retraction and deployment) – Cost Analysis • Design Objectives and Constraints – Minimum weight – Maximum component strength – High reliability – Low cost – Overall aircraft integration – Airfield compatibility © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics, 2017-2018 More Detailed Description of Tasks • Type (tricycle, tail gear, bicycle, etc) • Fixed (faired, or un-faired), or retractable, partially retractable • Height • Wheel base • Wheel track • The distance between main gear and c.g. • Strut diameter • Tire sizing (diameter, width) • Landing gear compartment (retracted) • Load on each strut © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics, 2017-2018 Historical Data Ratio of Landing gear W/MTOW http://www.dept.aoe.vt.edu/~mason/Mason_f/M96SC.html © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics, 2017-2018 Landing Gear Arrangements 后三点式 , touchdown speed <120km/h 前三点式, 240－280km/h Single main gear Bicycle Quadricycle Multi-bogey B47 sailplane B52 A380 © Shanghai Jiao Tong University – Dr. Wenbin Song School of Aeronautics and Astronautics, 2017-2018 Landing Gear Selection vs. Aircraft Weight 50000lb Single main wheel per strut 150000lb Two main wheel per strut 250000lb 400000lb Four wheel bogey with 4-6 wheels Two main wheel per strut/four wheel bogey 22680kg 68038kg 11398kg 181436kg Aircraft Weight Landing Gear Selection