1. ITU LCH Structural Design Criteria and Structure Analysis March 19, 2003

2. Outline General Strength Requirements Load Determination Structure Analysis

3. General Strength Requirements Loads Factor of Safety Strength and Deformation Proof of Structure Design limitations Miscellaneous Structure Strength Requirements FAR 27

4. Load Determination External Loads –Flight Loads –Ground Loads Inertia Loads Component Loads

5. Load Determination Flight Loads –Limit Maneuvering Load Factor Maximum 3.5 Minimum -1.0 load factor envelope

6. Load Determination Flight Loads –Symmetrical Pull-ups and Rolling Pull-outs –Gust Loads –Yawing Conditions

7. Load Determination Flight Loads –Load Calculation Flight Lab Input Parameters Results Analysis

8. Load Determination Ground Loads –Landing Load factor Energy absorption requirements –Limit drop height: 13 inches –Reserve energy drop height: 19.5 inches –With rotor lift Determine the load factor –Software

9. Load Determination Ground Loads –Landing load conditions: (landing gear with skids) Level landing with Vertical reactions only Level landing with Drag load Level landing with side Load One skid landing Special conditions

10. Load Determination Ground Loads –Ground Handing Hoisting Mooring Jacking Towing –Emergency Landing conditions

11. Load Determination Inertia Loads –Weights and its distribution –Equilibrium equations –Translational and rotational load factor –Distributed inertia loads

12. Load Determination Component Loads –Main rotor loads Load conditions –Flight load conditions –Ground flapping, ground gust –Torque Load calculation

13. Load Determination Component Loads –Fuselage, landing gear, and rotor pylon structures Load conditions –Flight load conditions –Landing Conditions –Ground Handing –Emergency Landing conditions Load calculation

14. Load Determination Component Loads –Control System Loads Limit pilot forces and torques –Tail rotor loads Flight loads Ground gust –Empennage loads –Transmission system

15. Structure Analysis Rotors Fuselage (including rotor pylon Landing gear, Empennage) Control system Transmission system