Basic Notes about the LG Design Process

• General design process
  • Tipback angle, clearance angle (length from CG to tail), overturn angle (<50),
  • NLG - straight (no angles)
    • Wheel sizing equation
  • Strut Type, NLG Shape (3D printed curve maybe)
  • Structural Analysis (PATRAN)
    • Material and strut dimensions (cross-section)
    • Strut placement end is wheel location not end of strut
      • Save photos for each iteration
    • 3 load cases, straight up(1.5-2 SF), side load, cross (~1)
    • Excel sheet with displacement and SF, Volume in mass
      • Changes in width, thickness, and materials (nice numbers)
  • CAD
    • Picking hardware, wheels, modeling the strut
    • Manufacturability and fitting with rest of plane (holes in the fuselage)
      • LG placement (nose and main) is near the bulkhead so that the load can be spread out
      • NLG connecting to the fuselage
      • Drawing for manufacturing
    • Fasten wheels without locking them
  • Manufacturing
    • Start as soon as possible, test materials (weight test), manufacturing plan, prototype to test process
      • Best aluminum for bending 3003, make a little thick
      • 7075 for nonbent aluminum
    • ACE Hardware
  • Testing
    • Static load test
    • Taxi test (no overturn, no lock-up)
    • Nylon vs. steel bolts during rough landing
• Weights
  • Landing gear is about max 10% of empty weight
  • NLG is about 35% of total LG weight
  • MLG is about 65% of total LG weight
• Deliverables for the LG Team
  • Mass and placement to aero & Manufacturing
• Received from other teams:
  • Fuselage length
  • Fuselage height
  • Fuselage width
  • CG (FROM NOSE)
  • Tail Lenth
  • MTOW