A ROADMAP TOWARD A FATIGUE QUALIFICATION PROCESS FOR MODERN TECHNOLOGY HELICOPTERS

The helicopter fatigue qualification process is critically reviewed to establish a roadmap, providing specific directions for a more efficient and unified qualification process. Specific improvements, various alternatives, and suggested unified approaches are discussed in terms of supporting rationales in the areas of coupon S-N data utilization, S-N curve reduction factor and curve shape, cycle counting method, structure classification, fatigue test requirement and in-service monitoring. Current status and an overview are presented of a parallel AGARD effort to compile a “Helicopter Fatigue Design Guide”.