§29.307 Proof of structure

(a) Compliance with th e stren gth an d deformation requi rements of t his Subpart must be shown for each critical loading condition accounting for the envi ronment t o whi ch t he structure will be exposed in operation. Structural analysis (static o r fatigue) may be used only if the structure conform s t o t hose for which experience has shown this m ethod t o be rel iable. In ot her cases, substantiating load tests must be made. (b) Proof of com pliance wi th the strength requirements of this Subpart must include: (1) Dynamic and endurance tests of rotors, rotor drives, and rotor controls; (2) Limit load tests o f th e co ntrol system, including control surfaces; (3) Operation t ests of t he control system; (4) Flight stress measurement tests; (5) Landing gear drop tests; and (6) Any additional tests required for new or unusual design features.